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Introduction: Superimposed high-frequency jet ventilation (SHFJV) is a new type of jet ventilation that simultaneously uses high- and low-frequency types of jet ventilation. We compared SHFJV with the conventional high-frequency jet ventilation (CHFJV) in interventional bronchoscopy in terms of safety and effectiveness. Methods : A multi-centre prospective random single-blind clinical trial was conducted by three interventional bronchoscopy centres. Patients who underwent diagnostic or therapeutic bronchoscopy under general anaesthesia were admitted and divided into two groups: SHFJV group (trial group) and CHFJV group (control group). PaO2 and PaCO2 were recorded before anaesthesia and during and after the procedure. SpO2 and etCO2 were recorded every 10 min throughout the procedure. Patients were observed until 24 h post-bronchoscopy. Results: Sixty patients were included in the study. Twenty-nine were in the trial group, and 31 were in the control group. Both groups had no significant differences in demographic data. In the control group, the PaO2 measured in the operation was higher than that in the trial group (p = 0.023). The values of etCO2 in the control group were more dispersed than those of the trial group. When the procedure time was over 90 minutes, the etCO2 in the control group significantly increased (p = 0.01), while the etCO2 in trial group remained stable (p = 0.594). There were more patients with PaCO2 ≥ 50 mmHg during the procedure in the control group than in the trial group (p = 0.042). Conclusion : SHFJV is effective and safe in interventional bronchoscopy. It may provide more effective and stabilised ventilation than CHFJV in cases with long procedure times., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Nasal cannulas and face masks are common oxygenation tools used in conventional oxygen therapy for patients undergoing endoscopic surgery with sedation. However, as a novel supraglottic ventilation technique, the application of supraglottic jet oxygenation and ventilation (SJOV) in endoscopic surgery has not been well established., Method: We searched six electronic databases from inception to January 16, 2024, to assess the oxygenation/ventilation efficacy and side effects of the of SJOV in endoscopic surgery. The primary outcome was the incidence of hypoxemia. The secondary outcomes were the incidence of respiratory depression and adverse effects (nasal bleeding, sore throat, and dry mouth)., Results: Nine trials involving 2017 patients were included. The results demonstrated that the incidence of hypoxemia was lower in the SJOV group compared with the conventional oxygen therapy (COT) group [9 trails; 2017 patients; risk ratio (RR) = 0.18; 95% confidence interval (CI), (0.11-0.28)]. Subgroup analyses showed that SJOV reduced the incidence of hypoxemia in the high-risk group but had no effect on the low-risk group. The incidence of respiratory depression is lower in SJOV than in COT, but has increased side effects such as dry mouth. There was no statistically significant difference in nose bleeding or sore throat between the two groups., Conclusion: Compared with the COT, the SJOV decreased the incidence of hypoxemia in high-risk patients during endoscopic surgery with sedation. There was an increased risk of dry mouth, but not of nose bleeding or sore throat, during endoscopic surgery under sedation., Competing Interests: Declaration of competing interest All authors declare that there are no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: High-frequency jet ventilation (HFJV) is used in pneumological endoscopy for rigid, diagnostic, and therapeutic bronchoscopies. It is unclear to what extent the unobstructed flow of respiratory gas from the patient's lungs causes microbial contamination of the surrounding air., Material and Methods: After the start of the HFJV (15 min) in 16 rigid bronchoscopies, airborne pathogen measurements were taken directly at the distal endoscope outlet, at examiner height (40 cm above the endoscope outlet), at a 2 m distance from the endoscope in the room and at the supply air outlet of the examination room using an RCS air sampler. The number and type of pathogens isolated in the air samples were then determined, as well as germs in the bronchoalveolar lavage fluid (BALF) from the patient's lungs., Results: An increased bacterial density (136 and 114 CFU/m 3 ) was detected directly at the distal end of the endoscope and at examiner height at a distance of 40 cm, which decreased significantly with increasing distance from the bronchoscope (98 CFU/m 3 at a distance of 2 m and 82 CFU/m 3 at the supply air outlet). The most frequently detected bacteria were Staphylococcus spp., Micrococcus spp. and Bacillus spp. In the BALF, pathogens could only be cultivated in four of 16 samples, but the same pathogens were detected in the BALF and the ambient air., Conclusion: When performing a rigid bronchoscopy, in which patients are mechanically ventilated in a controlled manner using an open HFJV system, there is an increased pathogen load in the ambient air and therefore a potential risk for the examiner., Competing Interests: Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

Background: During invasive ventilation, external flow jet nebulization results in increases in displayed exhaled tidal volumes (V T ). We hypothesized that the magnitude of the increase is inaccurate. An ASL 5000 simulator measured ventilatory parameters over a wide range of adult settings: actual V T , peak inspiratory pressure (PIP), and time to minimum pressure., Methods: Ventilators with internal and external flow sensors were tested by using a variety of volume and pressure control modes (the target V T was 420 mL). Patient conditions (normal, COPD, ARDS) defined on the ASL 5000 were assessed at baseline and with 3.5 or 8 L/min of added external flow. Patient-triggering was assessed by reducing muscle effort to the level that resulted in backup ventilation and by changing ventilator sensitivity to the point of auto-triggering., Results: Results are reported as percentage change from baseline after addition of 3.5 or 8 L/min external flow. For ventilators with internal flow sensors, changes in displayed exhaled V T ranged from 10% to 118%, however, when using volume control, actual increases in actual V T and PIP were only 4%-21% ( P = .063, .031) and 6%-24% ( P = .25, .031), respectively. Changes in actual V T correlated closely with changes in PIP ( P < .001; R 2 = 0.68). For pressure control, actual V T decreased by 3%-5% ( P = .031) and 4%-9% ( P = .031) with 3.5 and 8 L/min respectively, PIP was unchanged. With external flow sensors at the distal Y-piece junction, volume and pressure changes were statistically insignificant. The time to minimum pressure increased at most by 8% ( P = .02) across all modes and ventilators. The effects on muscle pressure were minimal (∼1 cm H 2 O), and ventilator sensitivity effects were nearly undetectable., Conclusions: External flow jet nebulization resulted in much smaller changes in volume than indicated by the ventilator display. Statistically significant effects were confined primarily to machines with internal flow sensors. Differences approached the manufacturer-reported variation in ventilator baseline performance. During nebulizer therapy, effects on V T can be estimated at the bedside by monitoring PIP., (Copyright © 2024 by Daedalus Enterprises.)

Objective: This study investigates the effects of tracheal stenosis on distal airway pressure during low-frequency jet ventilation (LFJV) in tracheal stenosis resection procedures, focusing on variables like stenosis size, depth, scope type, and inlet pressure., Methods: A 3D-printed human airway model was employed, featuring inserted tracheal stenoses of varied sizes and depths. Distal airway pressure was measured with 16 pressure transducers, and data were processed via MATLAB. The study varied stenosis size, depth, scope type, and inlet pressure during five sequential jet bursts under LFJV., Results: Using a subglottiscope resulted in significantly reduced distal airway pressure compared to a laryngoscope. Interestingly, neither stenosis size nor depth significantly influenced distal airway pressure. However, increased distance between the scope and stenosis raised normalized pressure. A linear rise in normalized distal airway pressure was noted with increased inlet pressure, regardless of stenosis dimensions., Conclusion: In this model, scope type and inlet pressure were noted to be significant determinants of distal airway pressure, while stenosis size and depth were not. The distance between the scope and the stenosis did influence distal pressures. These findings may have clinical implications for managing airway pressures in patients undergoing LFJV, potentially reducing the risk of ventilator-induced lung injury., Level of Evidence: NA (Basic Research) Laryngoscope, 134:2300-2305, 2024., (© 2023 The American Laryngological, Rhinological and Otological Society, Inc.)

Study Objective: To investigate post-procedural recovery as well as peri-procedural respiratory and hemodynamic safety parameters with prolonged use of high-frequency jet ventilation (HFJV) versus conventional ventilation in patients undergoing catheter ablation for atrial fibrillation., Design: Hospital registry study., Setting: Tertiary academic teaching hospital in New England., Patients: 1822 patients aged 18 years and older undergoing catheter ablation between January 2013 and June 2020., Interventions: HFJV versus conventional mechanical ventilation., Measurements: The primary outcome was post-anesthesia care unit (PACU) length of stay. In secondary analyses we assessed the effect of HFJV on intra-procedural hypoxemia, defined as the occurrence of peripheral hemoglobin oxygen saturation (SpO 2 ) <90%, post-procedural respiratory complications (PRC) as well as intra-procedural hypocarbia and hypotension. Multivariable negative binomial and logistic regression analyses, adjusted for patient and procedural characteristics, were applied., Main Results: 1157 patients (63%) received HFJV for a median (interquartile range [IQR]) duration of 307 (253-360) minutes. The median (IQR) length of stay in the PACU was 244 (172-370) minutes in patients who underwent ablation with conventional mechanical ventilation and 226 (163-361) minutes in patients receiving HFJV. In adjusted analyses, patients undergoing HFJV had a longer PACU length of stay (adjusted absolute difference: 37.7 min; 95% confidence interval [CI] 9.7-65.8; p = 0.008). There was a higher risk of intra-procedural hypocarbia (adjusted odds ratio [OR adj ] 5.90; 95%CI 2.63-13.23; p < 0.001) and hypotension (OR adj 1.88; 95%CI 1.31-2.72; p = 0.001) in patients undergoing HFJV. No association was found between the use of HFJV and intra-procedural hypoxemia or PRC (p = 0.51, and p = 0.97, respectively)., Conclusion: After confounder adjustment, HFJV for catheter ablation procedures for treatment of atrial fibrillation was associated with a longer length of stay in the PACU. It was further associated with an increased risk of intra-procedural abnormalities including abnormal carbon dioxide homeostasis, as well as intra-procedural arterial hypotension., Competing Interests: Declaration of Competing Interest M.S.S. has received grants for investigator-initiated trials not related to this manuscript from Merck & Co. He has received speaker fees from Mindray Medical International Limited, and from Fisher & Paykel Healthcare. He is an Associate Editor for BMC Anesthesiology and received unrestricted funds from philanthropic donors Jeffrey and Judith Buzen. J.W.W. is on an advisory board for HearCor Solutions and has received research support not related to this study from Anumana. The funders had no role in the design and conduct of the study, the collection, management, analysis, and interpretation of the data, the preparation, review, or approval of the manuscript; or the decision to submit the manuscript for publication. R.MA., T.M.T., B.A.A., A.S., E.A., L.J.W., F.C.L., G.C., P.T. and S.S. have no conflicts of interest. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (Copyright © 2023 Elsevier Inc. All rights reserved.)

BACKGROUND. High-frequency jet ventilation (HFJV) facilitates accurate probe placement in percutaneous ablation of lung tumors but may increase risk for adverse events, including systemic air embolism. OBJECTIVE. The purpose of this study was to compare major adverse events and procedural efficiency of percutaneous lung ablation with HFJV under general anesthesia to spontaneous respiration (SR) under moderate sedation. METHODS. This retrospective study included consecutive adults who underwent CT-guided percutaneous cryoablation of one or more lung tumors with HFJV or SR between January 1, 2017, and May 31, 2023. We compared major adverse events (Common Terminology Criteria for Adverse Events grade ≥ 3) within 30 days postprocedure and hospital length of stay (HLOS) of 2 days or more using logistic regression analysis. We compared procedure time, room time, CT guidance acquisition time, CT guidance radiation dose, total radiation dose, and pneumothorax using generalized estimating equations. RESULTS. Overall, 139 patients (85 women, 54 men; median age, 68 years) with 310 lung tumors (82% metastases) underwent 208 cryoablations (HFJV, n = 129; SR, n = 79). HFJV showed greater rates than SR for the treatment of multiple tumors per session (43% vs 19%, respectively; p = .02) and tumors in a nonperipheral location (48% vs 24%, p < .001). Major adverse event rate was 8% for HFJV and 5% for SR ( p = .46). No systemic air embolism occurred. HLOS was 2 days or more in 17% of sessions and did not differ significantly between HFJV and SR ( p = .64), including after adjusting for probe number per session, chronic obstructive pulmonary disease, and operator experience ( p = .53). Ventilation modalities showed no significant difference in procedure time, CT guidance acquisition time, CT guidance radiation dose, or total radiation dose (all p > .05). Room time was longer for HFJV than SR (median, 154 vs 127 minutes, p < .001). For HFJV, the median anesthesia time was 136 minutes. Ventilation modalities did not differ in the frequencies of pneumothorax or pneumothorax requiring chest tube placement (both p > .05). CONCLUSION. HFJV appears to be as safe as SR but had longer room times. HFJV can be used in complex cases without significantly impacting HLOS of 2 days or more, procedure time, or radiation exposure. CLINICAL IMPACT. Selection of the ventilation modality during percutaneous lung ablation should be based on patient characteristics and anticipated procedural requirements as well as operator preference.

Background: High frequency jet ventilation (HFJV) can be used to minimise sub-diaphragmal organ displacements. Treated patients are in a supine position, under general anaesthesia and fully muscle relaxed. These are factors that are known to contribute to the formation of atelectasis. The HFJV-catheter is inserted freely inside the endotracheal tube and the system is therefore open to atmospheric pressure., Aim: The aim of this study was to assess the formation of atelectasis over time during HFJV in patients undergoing liver tumour ablation under general anaesthesia., Method: In this observational study twenty-five patients were studied. Repeated computed tomography (CT) scans were taken at the start of HFJV and every 15 minutes thereafter up until 45 minutes. From the CT images, four lung compartments were defined: hyperinflated, normoinflated, poorly inflated and atelectatic areas. The extension of each lung compartment was expressed as a percentage of the total lung area., Result: Atelectasis at 30 minutes, 7.9% (SD 3.5, p = 0.002) and at 45 minutes 8,1% (SD 5.2, p = 0.024), was significantly higher compared to baseline 5.6% (SD 2.5). The amount of normoinflated lung volumes were unchanged over the period studied. Only a few minor perioperative respiratory adverse events were noted., Conclusion: Atelectasis during HFJV in stereotactic liver tumour ablation increased over the first 45 minutes but tended to stabilise with no impact on normoinflated lung volume. Using HFJV during stereotactic liver ablation is safe regarding formation of atelectasis., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Galmén et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Rationale and Objective: Percutaneous thermal ablative technique is a common radiological procedure for malignant lesions treatment. Controlled assisted ventilation during general anesthesia is the usual mode of ventilation, but high-frequency jet ventilation (HFJV) can be a helpful alternative for the operator. The objective was to evaluate the safety of HFJV during thermal ablation procedures., Materials and Methods: This monocentric prospective analysis included adult patients undergoing percutaneous thermal ablation procedures for abdominal tumor performed under HFJV. Procedures with a transpulmonary path were excluded. The primary outcome was the incidence of respiratory complications. Secondary outcomes included gas exchange modifications (hypercapnia, hypoxemia, pulmonary atelectasis) and the incidence of barotrauma., Results: Sixty patients were included during the study period. The mean duration time was 88 min. All procedures went according to the protocol and there was no respiratory complication. There was no barotrauma event. Three patients had an exhaled capnia above 45 mmHg at the end of the procedure which normalized within 10 min of conventional ventilation., Conclusion: HFJV during thermal ablation procedures is safe regarding gas exchange and barotrauma. This technique could be an interesting alternative to conventional ventilation during image-guided thermal ablation procedures. Clinical Trials database This study was registered in Clinical Trials database (NCT04209608)., (© 2023. Springer Science+Business Media, LLC, part of Springer Nature and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE).)

Objective: Manual jet ventilation is a specialized oxygenation and ventilation technique that is not available in all facilities due to lack of technical familiarity and fear of complications. The objective is to review our center's 15 year experience with low pressure low frequency jet ventilation (LPLFJV)., Methods: Retrospective review of procedures utilizing LPLFJV from 2005 to 2019 were performed collecting patient demographic, surgery type and complications. Fisher exact test, Chi square, and t -test were used to determine statistical significance., Results: Four hundred fifty-seven patients underwent a total of 891 microlaryngeal surgeries-279 cases for voice disorders, 179 for lesions, and 433 for airway stenosis. The peak jet pressure for all cases did not exceed 20 psi and average peak pressure for the last 100 procedures in this case series was 14.9 ± 4.6 psi. The average lowest oxygen saturation for all cases was 95% ± 0.6%. Brief intubation was required in 154 cases (17%). Surgical duration was significantly longer for cases requiring intubation P  < .001. The need for intubation was not associated with smoking or cardiopulmonary disease, but was strongly associated with body mass index (BMI). Intubation rates were 7% for normal weight (BMI < 25, N = 216), 13% for overweight (BMI 25-30, N = 282), 24% for obese (BMI 30-40, N = 342), and 37% for morbidly obese (BMI > 40, N = 52) patients. Three patients developed respiratory distress in the recovery unit and 2 patients required intubation., Conclusion: LPLFJV assisted by intermittent endotracheal intubation is an exceedingly safe and effective intraoperative oxygenation and ventilationmodality for a broad variety of laryngeal procedure.

High frequency jet ventilationis a mechanical lung ventilation method which uses a relatively high flow usually through an open system. This work examined the effect of high-frequency jet ventilation on respiratory parameters of an intubated patient simulated using a high-frequency jet ventilator attached to a ventilation monitor for measurements of ventilation parameters. The series of experiments altered specific parameters each time (respiratory rate, inspiratory-expiratory (I:E) ratio, and inspiratory pressure), under different lung compliances. A reduction of minute ventilation was observed alongside a rise in respiratory rate, with low airway pressures over the entire range of lung compliances. In addition, an I:E ratio of 2:1 to 1:1; and the tidal and minute volumes were directly related to the inspiratory pressure over all compliance settings. To conclude, the respiratory mechanics in high-frequency jet ventilation are very different from those of conventional rate ventilation in a lung model. Further studies on patients and/or a biological model are needed to investigate pCO2 and end-tidal carbon-dioxide during high-frequency jet ventilation.

High-frequency jet ventilation (HFJV) can reduce organ movement that otherwise complicates percutaneous image-guided ablation (IGA) procedures. This study describes feasibility and safety of the technique in routine use. We describe our method for the use of HFJV and present 169 consecutive cases, including IGA of tumors of the lung, liver, kidney, and pancreas. Intended oncological treatment was delivered in all cases and HFJV used for the duration of treatment in all except one case. We describe the characteristics of patients, procedures, and adverse events. It is feasible to use HFJV as the routine standard of care for IGA., Competing Interests: Conflicts of Interest: See Disclosures at the end of the article., (Copyright © 2022 International Anesthesia Research Society.)

Background: Ventilation strategies in atrial fibrillation ablation affect procedure outcomes by influencing catheter stability. Studies have highlighted favorable atrial fibrillation (AF) ablation outcomes with the use of high-frequency jet ventilation (HFJV) which has been shown to improve lesion durability, energy delivery, and tissue contact. However, this mode of ventilation is not readily available. In this systematic review, we highlight the available data on the use of very low tidal volume, high-frequency ventilation using standard ventilators that aim to provide settings similar to HFJV during AF ablations., Methods: Using a combination of search terms in databases and manual searches in bibliographies of identified articles, we reviewed all published data reported in the English language on the use of very low tidal volume with high-frequency ventilation during atrial fibrillation ablation., Results: A total of 4 manuscripts were identified; 3 cohort studies and 1 case report. The utilization of standard ventilators with a high-frequency, very low tidal volume ventilation strategy appears to closely mimic the catheter stability benefits that HFJV ventilators provide. Across the 3 cohort identified studies, the use of this ventilation strategy was associated with improved catheter stability, tissue contact, and a decrease in radiofrequency time. No increased risk was identified compared to standard ventilation., Conclusion: With a purpose of limiting thoracic excursion and cardiac movement, limited and sparse studies have shown improved outcomes with a very low tidal volume, high-frequency ventilation strategy. Additional studies are needed to solidify this easily accessible and widely available mode of ventilation., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: Laryngeal transoral surgery classically requires a neuromuscular block (NMB) to facilitate tracheal intubation and to improve surgical conditions. However, the short duration of most procedures and the potential complications of residual NMB lead to consider a no block approach. The hypothesis that intravenous anesthesia (remifentanil and propofol infusions) without NMB but including glottis topical lidocaine anesthesia would allow clinically acceptable laryngeal exposure and good surgical conditions was tested in the specific context of procedures undergone with High Frequency Jet Ventilation (HFJV)., Study Design: A prospective randomized clinical comparison., Methods: 66 consenting patients were planned to receive 0.6 mg·kg -1 rocuronium or saline at random. The outcome measurements included the time and conditions to complete suspended laryngoscopy, and the surgical conditions rated by the surgeon. Any vocal cord movement or coughing was recorded. Data were compared using a Wilcoxon rank-sum test for numerical variables and chi-square test for categorical ones. Treatment failure was defined as an impossible laryngoscopy or a grade 4 surgical field occurring at any time during surgery and was compared to its null theoretical value by a general z-test. An interim analysis after completion of 50% patients was performed using Pocock boundaries at 0.0294 significance levels., Results: A significant failure rate occurred in the non paralysed group (27%, p < 0.001). No coughing and no vocal cords movement occurred in the NMB group. Poorer surgical conditions were obtained without NMB (p = 0.011)., Conclusion: Inducing a deep NMB ensured improved conditions during direct laryngeal microsurgery with HFJV., (Copyright © 2021. Published by Elsevier Inc.)

Background: High frequency jet ventilation (HFJV) is an open ventilating technique to maintain ventilation for emergency or difficult airway. However, whether jet ventilation or conventional oxygen therapy (COT) is more effective and safe in maintaining adequate oxygenation, is unclear among patients with airway stenosis during bronchoscopic intervention (BI) under deep sedation., Methods: A prospective randomized cohort study was conducted to compare COT (high flow oxygen) with normal frequency jet ventilation (NFJV) and HFJV in oxygen supplementation during BI under deep sedation from March 2020 to August 2020. Patients receiving BI under deep sedation were randomly divided into 3 parallel groups of 50 patients each: the COT group (fractional inspired oxygen (FiO 2 ) of 1.0, 12 L/min), the NFJV group (FiO 2 of 1.0, driving pressure of 0.1 MPa, and respiratory rate (RR) 15 bpm) and the HFJV Group (FiO 2 of 1.0, driving pressure of 0.1 MPa, and RR of 1200 bpm). Pulse oxygen saturation (SpO 2 ), mean arterial blood pressure and heart rate were recorded during the whole procedure. Arterial blood gas was examined and recorded 15 min after the procedure was initiated. The procedure duration, dose of anesthetics, and adverse events during BI in the three groups were also recorded., Results: A total of 161 patients were enrolled, with 11 patients excluded. The clinical characteristics were similar among the three groups. PaO 2 of the COT and NFJV groups was significantly lower than that of the HFJV group (P < 0.001). PaO 2 was significantly correlated with ventilation mode (P < 0.001), body mass index (BMI) (P = 0.019) and procedure duration (P = 0.001). Multiple linear regression showed that only BMI and procedure duration were independent influencing factors of arterial blood gas PaO 2 (P = 0.040 and P = 0.002, respectively). The location of airway lesions and the severity of airway stenosis were not statistically correlated with PaCO 2 and PaO 2 ., Conclusions: HFJV could effectively and safely improve intra-operative PaO 2 among patients with airway stenosis during BI in deep sedation, and it did not increase the intra-operative PaCO 2 and the risk of hypercapnia. PaO 2 was correlated with ventilation mode, BMI and procedure duration. Only BMI and procedure duration were independent influencing factors of arterial blood gas PaO 2 . PaCO 2 was not correlated with any preoperative factor., Trial Registration: Chinese Clinical Trial Registry. Registration number, ChiCTR2000031110 , registered on March 22, 2020.

Imaging is used in human medicine to diagnose disease and monitor treatment efficacy. Computed tomography (CT) positron emission tomography (PET) and magnetic resonance (MR) are applied to animal models of infectious diseases to increase data quality, enhance their relevance to the clinical situation, and to address ethical issues through reduction of numbers and refinement of study designs. The time required for collection of MR and PET-CT scans means that normal breathing produces motion artefacts that can render images unacceptable. We report, for the first time, the use of high frequency jet ventilation (HFJV) for respiratory management during imaging of macaques. HFJV enables continuous gaseous exchange, resulting in cessation of spontaneous breathing motion thus providing a motionless field without the potential stresses induced by repeated breath-hold strategies.

Objective: To review pregnancy outcomes and the safety of jet ventilation use in the gravid patient undergoing surgical airway intervention., Methods: A multi-institutional retrospective review of medical records was performed to identify women who underwent low-frequency jet ventilation during pregnancy for surgical treatment of airway stenosis. Postoperative complications were noted, and patients were interviewed regarding pregnancy outcomes., Results: Six women were included in this series. No immediate complications relating to anesthesia or surgical intervention were noted in five of the six women. One patient with a well-known history of uncontrolled seizures experienced seizure activity postoperatively. One patient returned to the operating room at a later date for debridement of tracheal crusts. Five mothers delivered via cesarean section and one via spontaneous vaginal delivery. The mean gestation age was 37.3 weeks. One of the six infants delivered prematurely and three were delivered at low birth weight. Three of the six infants required elevated care immediately post-delivery but, at present, all are in good health., Conclusion: Low-frequency jet ventilation and surgical management of airway stenosis should be recognized as a safe treatment option in the gravid patient. Surgical intervention should not be delayed in patients with severe symptoms, particularly given the potential risk associated with prolonged corticosteroid use., Level of Evidence: 4.

Objectives: To assess whether manual jet ventilation can safely be performed with variable anesthesia and operating room (OR) staff experience levels and communication skills., Methods: Jet ventilation procedures for airway stenosis at a single institution over 35 months were retrospectively reviewed. OR and anesthesia staff were assigned scores based on experience level and communication skills. Data were analyzed for any association between the experience or communication skills of the staff and the successful use of jet ventilation, complication rate, or ultimate patient outcome, controlling for intraoperative variables and patient and airway complexity. A detailed preoperative surgeon-led communication protocol was followed in all cases., Results: Seventy procedures in 46 patients were performed. Jet ventilation was successful in 69 of 70 cases. No relationship was found between staff experience or communication scores and the successful use of jet ventilation, complication rate, or ultimate patient outcome. The percentage of cases performed with a fully experienced team was low, at 7.1%. The experience level of the certified registered nurse anesthetist was significantly associated with likelihood of using an adequate paralytic dose upfront (P = 0.017), which in turn correlated with shorter anesthesia time by 19.7 minutes (P = 0.0131); however, neither affected complication rate nor ultimate patient outcome. The statements above remained true in cases of medically complex patients, difficult airways with high degrees of stenosis, and multiple shift changes., Conclusions: Manual jet ventilation can be performed safely even in settings of lower staff experience level or communication skills given a surgeon experienced in the technique and a strict communication protocol., Level of Evidence: 4 Laryngoscope, 130:S1-S13, 2020., (© 2019 The American Laryngological, Rhinological and Otological Society, Inc.)

Background and Objectives: Cardiac Magnetic Resonance Imaging (MRI) is a technique used for evaluation of children with congenital heart diseases. General anesthesia ensures immobility, particularly in uncooperative patients. However, chest wall movements can limit good quality scans. Prolonged apnea may be necessary to decrease respiratory motion artefacts, potentially leading to hypoxemia and other adverse events. The use of a high frequency jet ventilator may be a solution avoiding chest wall movements., Case Report: We report four cases of pediatric patients, ASA II, aged between 4 and 15 years-old, scheduled for cardiac MRI. General anesthesia was proposed and parental informed consent was obtained. After general anesthesia was induced, an uncuffed endotracheal tube was inserted. Then, a 7Fr×40 cm catheter was placed through the endotracheal tube. The proximal outlet of the catheter was attached through a connecting tube to a high frequency jet ventilator (Monsoon III®, Acutronic Medical Systems). Good quality MRI images were obtained. At the end of the procedures, we observed increased salivation and increased end-tidal CO 2 (60-70 mmHg), in all patients. The patients were extubated after normocapnia was achieved and neuromuscular blockade reversed. Following appropriate recovery time, the four children were discharged home the same day., Conclusions: This case series demonstrates that the use of a high frequency jet ventilator for cardiac MRI was feasible, safe, providing good quality cardiac imaging and avoiding anesthesia personnel to be inside the hazardous environment of MRI room. Future studies are needed to confirm its safety and efficiency in pediatric patients., (Copyright © 2019 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.)

Background & Aims: Ablation plays an important role in the treatment of hepatocellular carcinoma. Because image-guided navigation technology has recently entered the clinical setting, we aimed to analyse its safety, therapeutic and procedural efficiency., Methods: Retrospective analysis of patients treated with stereotactic image-guided microwave ablation (SMWA) between January 2015 and December 2017. Interventions were performed using computertomography-guidance with needle trajectory, ablation planning and automatic single-marker patient registration. Needle placement and ablation coverage was controlled by image fusion under general anaesthesia with jet-ventilation., Results: In total 174 ablations were performed in 88 patients during 119 interventions. Mean age was 66 (46-84) years, 74 (84.1%) were men and 74% were Child Pugh Class A. Median tumour size was 16 (4-45) mm, 62.2% were BCLC A. Median lateral and longitudinal error of needle placement were 3.2 (0.2-14.1) and 1.6 (0-15.8) mm. Median one tumour (1-4) was ablated per session. One patient developed a Dindo IIIb (0.8%) complication, six minor complications. After re-ablation of 12 lesions, an efficacy rate of 96.3% was achieved. Local tumour progression was 6.3% (11/174). Close proximity to major vessels was significantly correlated with local tumour progression (P < .05). Median overall follow-up was 17.5 months after intervention and 24 months after initial diagnosis. BCLC stage, child class and previous treatment were significantly correlated with overall survival (P < .05)., Conclusion: Stereotactic image-guided microwave ablation is a safe and efficient treatment for HCC offering a curative treatment approach in general and in particular for lesions not detectable on conventional imaging or untreatable because of difficult anatomic locations., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To assess if high frequency jet ventilation (HFJV) is associated with reduced odds of death or discharge home on oxygen in preterm infants. Methods: A case control study (1 February 2010 - 1 June 2014) comparing the primary outcome as "death or discharge home on oxygen" in preterm infants who needed HFJV (Cases) versus those who did not (Controls). Controls were matched to cases (1:1) on gestation, birthweight, gender, place of birth, growth status, antenatal glucocorticoids, and dexamethasone as treatment for severe bronchopulmonary dysplasia (BPD). Logistic regression analysis was used to control for confounders. Results: Data on all preterm infants who needed HFJV (Cases: n  = 50) and 50 controls during the study period were analysed. Primary outcome was more frequent in cases versus controls, but not significant after adjusting for mean airway pressure and adjuvant therapy (e.g. diuretics) [aOR: 1.46 (0.23-9.14), p  = .687]. Death before discharge [odds ratios (OR): 6.00 (1.34-55.2), p  = .013] was more frequent in cases; discharge on home oxygen [OR: 0.88 (0.27-2.76), p  = 1.000] was comparable between groups. Duration of oxygen [adjusted hazard ratios (aHR): 1.23 (0.69-2.17), p  = .475] and incidence of treatment warranting retinopathy of prematurity [aOR: 0.10 (0.01-1.96), p  = .127] was not significant between cases versus controls. Conclusions: HFJV was not associated with reduced odds of death or discharge home on oxygen in preterm infants in our study. Adequately powered randomized trials are required to assess the efficacy and safety of HFJV in preterm infants.

Percutaneous cryoablation of pulmonary tumors at the posterior lung base is challenging due to diaphragmatic motion and the requirement for prone positioning. High-frequency jet ventilation allows oxygenation and ventilation with minimal diaphragmatic movement. In this case report, we describe the use of high-frequency jet ventilation in the prone position to facilitate the cryoablation of a peridiaphragmatic pulmonary neoplasm.

Background: Supraglottic jet oxygenation and ventilation (SJOV) can effectively maintain adequate oxygenation in patients with respiratory depression, even in apnea patients. However, there have been no randomized controlled clinical trials of SJOV in obese patients. This study investigated the efficacy and safety of SJOV using WEI Nasal Jet tube (WNJ) for obese patients who underwent hysteroscopy under intravenous anesthesia without endotracheal intubation., Methods: A single-center, prospective, randomized controlled study was conducted. The obese patients receiving hysteroscopy under intravenous anesthesia were randomly divided into three groups: Control group maintaining oxygen supply via face masks (100% oxygen, flow at 6 L/min), the WNJ Oxygen Group with WNJ (100% oxygen, flow: 6 L/min) and the WNJ SJOV Group with SJOV via WNJ [Jet ventilator working parameters:100% oxygen supply, driving pressure (DP) 0.1 MPa, respiratory rate; (RR): 15 bpm, I/E; ratio 1:1.5]. SpO 2 , P ET CO 2 , BP, HR, ECG and BIS were continuously monitored during anesthesia. Two-Diameter Method was deployed to measure cross sectional area of the gastric antrum (CSA-GA) by ultrasound before and after SJOV in the WNJ SJOV Group. Episodes of SpO 2 less than 95%, P ET CO 2 less than 10 mmHg, depth of WNJ placement and measured CSA-GA before and after jet ventilation in the WNJ SJOV Group during the operation were recorded. The other adverse events were collected as well., Results: A total of 102 patients were enrolled, with two patients excluded. Demographic characteristics were similar among the three groups. Compared with the Control Group, the incidence of P ET CO 2  < 10 mmHg, SpO 2  < 95% in the WNJ SJOV group dropped from 36 to 9% (P = 0.009),from 33 to 6% (P = 0.006) respectively,and the application rate of jaw-lift decreased from 33 to 3% (P = 0.001), and the total percentage of adverse events decreased from 36 to 12% (P = 0.004). Compared with the WNJ Oxygen Group, the use of SJOV via WNJ significantly decreased episodes of SpO 2  < 95% from 27 to 6% (P = 0.023), P ET CO 2  < 10 mmHg from 33 to 9% (P = 0.017), respectively. Depth of WNJ placement was about 12.34 cm in WNJ SJOV Group. There was no significantly difference of CSA-GA before and after SJOV in the WNJ SJOV Group (P = 0.234). There were no obvious cases of nasal bleeding in all the three groups., Conclusions: SJOV can effectively and safely maintain adequate oxygenation in obese patients under intravenous anesthesia without intubation during hysteroscopy. This efficient oxygenation may be mainly attributed to supplies of high concentration oxygenation to the supraglottic area, and the high pressure jet pulse providing effective ventilation. Although the nasal airway tube supporting collapsed airway by WNJ also plays a role. SJOV doesn't seem to increase gastric distension and the risk of aspiration. SJOV can improve the safety of surgery by reducing the incidence of the intraoperative involuntary limbs swing, hip twist and cough., Trial Registration: Chinese Clinical Trial Registry. Registration number, ChiCTR1800017028, registered on July 9, 2018.

Objective: To describe the use of balloon dilation with non-invasive ventilation in the treatment of pregnant patients with idiopathic subglottic stenosis., Methods: The medical charts of four consecutive patients who underwent jet ventilation or high-flow nasal cannula oxygenation with balloon dilation for the treatment of idiopathic subglottic stenosis during pregnancy were reviewed., Results: Objective improvement of subglottic stenosis was seen in all four cases, with end-result Myer-Cotton grade 1 lesions down from pre-procedure grade 3 lesions. Patients also reported subjective improvements in symptomatology, with no further airway issues. All patients delivered normally, at term., Conclusion: Laryngeal dilation with continuous radial expansion pulmonary balloons using non-invasive ventilation for the treatment of idiopathic subglottic stenosis in pregnant patients is safe and efficacious, and should be the first line treatment option for this patient population. The improvement in symptoms, and lack of labour and pregnancy complications, distinguish this method of treatment from others reported in the literature.

Objectives: To report the feasibility and efficacy of percutaneous ablation of small hepatic malignant tumors that are invisible on ultrasound and inaccessible using in-plane CT guidance, using a combination of high-frequency jet-ventilation (HFJV) and electromagnetic (EM) needle tracking. Methods: This study reviewed 27 percutaneous ablations of small hepatic tumors (<2 cm) performed using EM navigation-based probe placement and HFJV. All lesions were invisible on ultrasound and difficult to reach on CT requiring a double-oblique approach. The primary outcome was technical efficacy, defined as complete lesion coverage, and evaluated on contrast enhanced MRI after 3 and 6 months. Needle placement accuracy, the number of control CT acquisitions, procedure time, complications and radiation doses were assessed. Results: Twenty-one patients with 27 treated lesions (14 hepatocellular carcinomas and 13 metastases) were included in this study. Mean tumor size was 12 ± 5.7 mm. Thirty-three percent of the lesions were located on the hepatic dome. Complete ablation was obtained in 100% at the 3- and 6-month MRI follow-up. The ablation probe was correctly placed on the first pass in 96%, with a mean path-to-tumor angle of 7 ± 4 degrees and a mean tip-to-tumor distance of 22 ± 19mm. A readjustment for additional overlapping application resulted in complete treatment in 4 patients. Needle placement took a mean 23 ± 12 min with mean radiation doses of 558 mGy*cm. No major complications were reported. Conclusion: Percutaneous liver ablation of lesions that cannot be seen on US and requiring out-of-plane CT access can be successfully and safely treated using electromagnetic-based navigation and jet-ventilation.

Introduction: High frequency jet (HFJV) and oscillatory (HFOV) ventilation were used to rescue newborns with congenital diaphragmatic hernia (CDH), who failed conventional mechanical ventilation (CV). Changes in ventilator settings and pulmonary gas exchange were evaluated following transition to high frequency ventilation (HFV)., Methods: Records of patients with CDH rescued with HFV prior to surgical intervention between 2006 and 2015 were reviewed. Mean airway pressure (Pāw) and arterial blood gases during CV and those obtained within the first hour of HFV were compared. A composite repeated measure analysis was performed to evaluate longitudinal and intergroup variances., Results: Twenty-seven patients were rescued from CV, 16 by HFJV and 11 by HFOV. The two groups had similar gestational ages and birth weights. Prior to HFV, both groups had similar Pāw, PaCO2, FiO2 and PaO2. HFV was associated with a significant improvement in ventilation, and the rate of decrease of PaCO2 was no different between groups. There was a significantly higher increase in Pāw increase with HFOV compared to HFJV., Conclusions: In newborns with CDH rescued with HFV, ventilation improved but Pāw was significantly lower in patients supported with HFJV compared to HFOV.

Introduction: The failure rates of intubation and/or mask ventilation are higher in patients with neck or upper airway disease. To ensure oxygenation, rescue trans-tracheal jet ventilation (RTTJV) may be used. In this critical situation, a high rate of complications has been reported. The aim of this study was to report RTTJV performed by a jet ventilator with an end-expiratory pressure control in an experienced institution., Patients and Methods: From a computerised database of 63,905 anaesthesia cases, the anaesthetic reports of patients who underwent emergency RTTJV during intubation were studied retrospectively. The following information were analysed: anaesthetic procedures, data from the monitoring: lowest SpO 2 , duration of SpO 2 <90%, and complications. Success of emergency RTTJV was defined when SpO 2 was>90% under jet ventilation., Results: RTTJV was used in 31 patients, of whom 26 had upper airway cancer, (pre-treatment, n=9, post-treatment, n=17). Difficult intubation was anticipated in 15 out of 31 cases including six fiber-optic-aided intubations under spontaneous ventilation. RTTJV was effective in all cases with quick restoration of oxygenation (SpO 2 >90%). During jet ventilation, final airway control was performed either by oral intubation (n=25) or tracheotomy (n=1) in a short delay (mean: 8.1±1.7min). Subcutaneous emphysema was observed in one case without pneumothorax., Conclusion: RTTJV with end-expiratory pressure control allowed oxygenation during difficult intubation, with a low rate of complications., (Copyright © 2017 Société française d'anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.)

Objective: Microlaryngeal surgery requires teamwork between surgeons and anesthesiologists. High-frequency jet ventilation (HFJV) is an artificial breathing technique, preferred during endolaryngeal interventions, which offers a good solution for the requirements. Most studies investigating independent risk factors for intraoperative complications during HFJV in endolaryngeal surgery (ELS) has been retrospective and not standardized and the anesthetic approach has not been standardized. This prospective cohort study aimed to identify risk factors of complications related to HFJV in ELS under a standardized anesthesia regimen., Methods: 243 patients who underwent ELS with infraglottic HFJV were investigated. Infraglottic jet ventilation catheter was placed and anesthesia was standardized. Demographic and operative data were noted. Hemodynamics, SpO2 and end-tidal CO2 were recorded at regular intervals. Complications such as hemodynamic disturbances, respiratory problems, barotrauma, equipment failure and requirement for conventional ventilation were also documented., Results: 222 patients were included. Hypoxia, hypercapnia and the need for intubation were observed in 20(9%), 4(1.8%), 10(4.5%) patients. Bradycardia, hypotension and arrhythmia were observed in six (2.7%), 24(10.8%), and four (1.8%) patients respectively. Respiratory complications were associated with body mass index (BMI) (p < 0.001, OR: 1.57, 95%CI: 1.31–1.88) and previous major airway surgery (p < 0.001, OR: 34.0, 95%CI:3.52–328.24), whereas hemodynamic complications were associated with duration of the operation (p = 0.034, OR:1.04, 95%CI:1.0–1.09) and history of previous major airway surgery (p = 0.005, OR:9.57, 95%CI:1.97–46.49)., Conclusion: Infraglottic HFJV can be evaluated as an alternative breathing technique to conventional ventilation during endolaryngeal interventions. However, longer operation and previous laryngeal surgeries can increase the incidence of respiratory complications.

Background: Electrical impedance tomography (EIT) is a tool to monitor regional ventilation distribution in patient's lungs under general anesthesia. The objective of this study was to assess the regional ventilation distribution using different driving pressures (DP) during high frequency jet ventilation (HFJV)., Methods: Prospective, observational, cross-over study. Patients undergoing rigid bronchoscopy were ventilated HFJV with DP 1.5 and 2.5 atm. Hemodynamic and ventilation parameters, as well as ventilation in different regions of the lungs in percentage of total ventilation, assessed by EIT, were recorded., Results: Thirty-six patients scheduled for elective rigid bronchoscopy. The final analysis included thirty patients. There was no significant difference in systolic, diastolic and mean arterial blood pressure, heart rate, and peripheral saturation between the two groups. Peak inspiratory pressure, mean inspiratory pressure, tidal volume, and minute volume significantly increased in the second, compared to the first intervention group. Furthermore, there were no statistically significant differences between each time profiles in all ROI regions in EIT., Conclusions: In our study intraoperative EIT was an effective method of functional monitoring of the lungs during HFJV for rigid bronchoscopy procedure. Lower driving pressure was as effective in providing sufficient ventilation distribution through the lungs as the higher driving pressure but characterized by lower airway pressure., Trial Registration: The study was registered on ClinicalTrials.gov under no. NCT02997072 .

Aim: To evaluate the effect of high-frequency jet ventilation (HFJV) in place of standard intermittent positive-pressure ventilation (IPPV) on procedure duration, patient radiation dose, complication rates, and outcomes during CT-guided cryoablation of small renal tumours., Materials and Methods: One hundred consecutive CT-guided cryoablation procedures to treat small renal tumours under general anaesthesia were evaluated-50 with standard IPPV and 50 after the introduction of HFJV as standard practice. Anaesthesia and procedural times, ionising radiation dose, complications, and 1-month post-treatment outcomes were collected., Results: HFJV was feasible and safe in all cases. Mean procedure time and total anaesthetic time were shorter with HFJV (p = <0.0001). The number of required CT acquisitions (p = 0.0002) and total procedure patient radiation dose (p = 0.0027) were also lower in the HFJV group compared with the IPPV group. There were a total of four complications of Clavien-Dindo classification 3 or above-three in the IPPV group and one in the HFJV group. At 1-month follow-up, two cases (both in the IPPV group) demonstrated subtotal treatment. Both cases were subsequently successfully retreated with cryoablation., Conclusion: By reducing target tumour motion during CT-guided renal cryoablation, HFJV can reduce procedure times and exposure to ionising radiation. HFJV provides an important adjunct to complex image-guided interventions, with potential to improve safety and treatment outcomes.

Background: High frequency jet ventilation (HFJV) is a method of ventilation that has gained renewed interest over the recent years as it can reduce organ movement to near static conditions, thus enhancing surgical precision in minimal invasive procedures, for example, ablation procedures for atrial fibrillation and solid organ tumours. The aim of this review was to create a summary of the current evidence concerning the clinical use of HFJV for ablative procedures., Method: PubMed was searched for the key words high frequency ventilation and ablation January 1990-December 2016., Result: The search initially identified 34 papers, 14 met the inclusion criteria. Articles in other languages than English (n = 1), comments regarding other articles (n = 4) and articles that did not include HFJV or ablative procedures (n = 15) were excluded. Two articles were added from references in papers included from the primary search. Sixteen studies were finally included in the review; four updates/reviews and 12 papers with results from studies of HFJV on humans, with a total of 889 patients; 498 patients ventilated with HFJV and 391 controls. There were no randomised studies. The overall scientific quality of the studies was low., Conclusion: There is a lack of well-designed studies evaluating HFJV during ablation procedures. The available information, while sparse, supports the effect of less tissue movement, resulting in better surgical precision and outcome; such as shorter procedural time, fewer shock waves (ESWL) and less recurrence of atrial fibrillation. Randomised controlled studies are needed in this promising area of research to prove its superiority to standard ventilation., (© 2017 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Background: Patent ductus arteriosus (PDA) treatment is typically pharmacologic, but if unsuccessful, surgical ligation is commonly performed. High-frequency jet ventilation (HFJV) is used at the University of Iowa Stead Family Children's Hospital for extremely low birth weight infants. Historically, neonates requiring PDA ligation were temporarily transferred to conventional ventilation (CV) prior to surgery., Objective: The objective of this study was to determine whether conversion was necessary., Methods: This retrospective cohort analysis examined outcomes following PDA ligation from 2014 to 2016 at the University of Iowa's Stead Family Children's Hospital. Infants who were transferred to CV prior to surgery and returned to HFJV postprocedure are referred to as the CV cohort. The HFJV cohort infants remained on HFJV throughout., Results: We found no significant increases in morbidity or mortality with the use of intraoperative HFJV and potentially show some benefit through greater reduction in serum CO 2 ., Conclusions: Mode of ventilation during PDA ligation does not affect surgical morbidity or mortality or short-term clinical outcomes. Conversion to CV from HFJV is not necessary.

A difficult airway may lead to hypoxia and brain damage. The WEI Nasal Jet Tube (WNJ) is a new nasal pharyngeal tube that applies supraglottic jet oxygenation and ventilation (SJOV) for patients during tracheal intubation without the need for mask ventilation. We evaluated the effectiveness and safety of SJOV-assisted fibre-optic bronchoscopy (FOB) using the WNJ in the management of difficult tracheal intubations. A total of 50 adult patients with Cormack-Lehane grade ≥3 and general anesthesia with tracheal intubation were randomly assigned to either the laryngeal mask airway (LMA) or WNJ groups. The primary outcome was the percentage of patients with SpO 2 values lower than 94 % during intubation. The proportion of successful intubations, total time of intubation, and associated complications were also recorded. The percentage of patients with SpO 2 values lower than 94 % during intubation was significantly higher in the LMA group (25 % in the LMA vs. 0 % in the WNJ, P = 0.01). Although there were no statistically significant differences in the total success rates of intubation, the first-attempt success rate was significantly higher in the WNJ group (100 vs. 79.2 %, P = 0.02). The total time required for intubation with the WNJ was shorter than that of the LMA (73.4 vs. 99.5 s, P < 0.001), although the duration of fibre-optic intubation was similar. The incidence of complications was similar between the two groups. SJOV-assisted FOB using the WNJ improved oxygenation and successful tracheal intubation in the management of difficult airways. This technique can be used as an alternative approach to improve success and minimize hypoxia during difficult airway management.

Background: High-frequency jet ventilation (HFJV) has been used in conjunction with conventional ventilation for infants with respiratory failure. We sought to identify parameters that were associated with successful application of HFJV in patients with hypercapnic respiratory failure., Methods: A single-center, retrospective review of infants who received HFJV was conducted. Subjects were enrolled if birthweight was ≤2,000 g and capillary P CO 2 was ≥55 mm Hg. Ventilator parameters and physiologic data were recorded at 1 h before HFJV initiation and at hours 1, 4, and 6 following conversion. Subjects were classified as responders if capillary P CO 2 was reduced by ≥10% after 1 h of HFJV. Data included peak inspiratory pressure, PEEP, capillary P CO 2 , and oxygen saturation index (equal to mean airway pressure × F IO 2 × 100/S pO 2 ). Because the data were not normally distributed, they are reported as median (interquartile range), and the Mann-Whitney test was used to assess differences in continuous data between groups. Categorical data were analyzed using a chi-square and Fisher exact test., Results: Thirty-four premature infants ( n = 24 male) were studied. Twenty-five subjects were classified as responders and demonstrated a significant reduction of capillary P CO 2 and F IO 2 and increased pH within the first hour. The non-responders demonstrated a higher conventional ventilation peak inspiratory pressure (25 cm H 2 O vs 19 cm H 2 O, P = .005) and had a greater postmenstrual age (30 weeks vs 26.5 weeks, P = .01). This group had a higher oxygen saturation index (7.25 vs 3.36, P = .03) and F IO 2 requirements (0.6 vs 0.35, P = .038) at 4 h., Conclusions: We identified that lower postmenstrual age, improvements in capillary P CO 2 and pH at 1 h, and a reduction of F IO 2 were associated with good response to HFJV. These data may help to identify patients who are likely to benefit from HFJV in the neonatal intensive care unit., Competing Interests: The authors have disclosed no conflicts of interest., (Copyright © 2017 by Daedalus Enterprises.)

Background: Hypoventilation is the main reason for hypoxia during upper gastrointestinal endoscopy procedures with sedation. The key to preventing hypoxia is to maintain normal ventilation during the procedure. We introduced supraglottic jet oxygenation and ventilation (SJOV) through a new Wei nasal jet tube (WNJ) to reduce the incidence of hypoxia in patients sedated with propofol during upper gastrointestinal endoscopy procedures., Methods: In a multicentre, prospective randomized single-blinded study, 1781 outpatients undergoing routine upper gastrointestinal endoscopy who were sedated with propofol by an anaesthetist were randomized into the following three groups: the supplementary oxygen via nasal cannula group [nasal cannula oxygen: O 2 (2 litres min -1 ) was administered via a nasal cannula]; the supplementary oxygen via WNJ group [WNJ oxygen: O 2 (2 litres min -1 ) was administered through a WNJ]; and the SJOV via WNJ group (WNJ SJOV: SJOV was administered via WNJ) at three centres from March 2015 to July 2016. The primary outcome of interest was the incidence of hypoxia (peripheral oxygen saturation of 75-89%). Other adverse events were also recorded., Results: Supraglottic jet oxygenation and ventilation decreased the incidence of hypoxia from 9 to 3% ( P <0.0001). No severe hypoxia occurred in the WNJ SJOV group, one instance occurred in the WNJ oxygen group, and two instances were observed in the nasal cannula oxygen supply control group. Supraglottic jet oxygenation and ventilation-related minor adverse events increased significantly within 1 min after the procedure but decreased 30 min later., Conclusions: The use of SJOV during upper gastrointestinal endoscopy for patients who are sedated with propofol reduces the incidence of hypoxia, with minor and tolerable adverse events. Supraglottic jet oxygenation and ventilation has a favourable risk-to-benefit ratio and may improve patient safety., Clinical Trial Registration: NCT02436018., (© The Author 2017. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com)

Objective: The purpose of the present study is to evaluate the accuracy and safety of antenna placement performed with the use of a CT-guided stereotactic navigation system for percutaneous ablation of liver tumors and to assess the safety of high-frequency jet ventilation for target motion control., Materials and Methods: Twenty consecutive patients with malignant liver lesions for which surgical resection was contraindicated or that were not readily visible on ultrasound or not accessible by ultrasound guidance were included in the study. Patients were treated with percutaneous microwave ablation performed using a CT-guided stereotactic navigation system. High-frequency jet ventilation was used to reduce liver motion during all interventions. The accuracy of antenna placement, the number of needle readjustments required, overall safety, and the radiation doses were assessed., Results: Microwave ablation was completed for 20 patients (28 lesions). Performance data could be evaluated for 17 patients with 25 lesions (mean [± SD] lesion diameter, 14.9 ± 5.9 mm; mean lesion location depth, 87.5 ± 27.3 mm). The antennae were placed with a mean lateral error of 4.0 ± 2.5 mm, a depth error of 3.4 ± 3.2 mm, and a total error of 5.8 ± 3.2 mm in relation to the intended target. The median number of antenna readjustments required was zero (range, 0-1 adjustment). No major complications were related to either the procedure or the use of high-frequency jet ventilation. The mean total patient radiation dose was 957.5 ± 556.5 mGy × cm, but medical personnel were not exposed to irradiation., Conclusion: Percutaneous microwave ablation performed with CT-guided stereotactic navigation provides sufficient accuracy and requires almost no repositioning of the needle. Therefore, it is technically feasible and applicable for safe treatments.

The safety of high pressure source ventilation (jet ventilation) is dependent upon upper airway patency to facilitate adequate passive expiration and prevent increasing intrathoracic pressure and its associated deleterious sequelae. Distortions in airway anatomy may make passive expiration inadequate or impossible in some patients. We report the elective use of the Ventrain device to provide ventilation in a clinical setting of upper airway obstruction in a patient with post radiation fibrosis that had previously prevented passive expiration during attempted high pressure source ventilation., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Transtracheal jet ventilation (TTJV) is recommended in several airway guidelines as a potentially life-saving procedure during the 'Can't Intubate Can't Oxygenate' (CICO) emergency. Some studies have questioned its effectiveness., Methods: Our goal was to determine the complication rates of TTJV in the CICO emergency compared with the emergency setting where CICO is not described (non-CICO emergency) or elective surgical setting. Several databases of published and unpublished literature were searched systematically for studies describing TTJV in human subjects. Complications were categorized as device failure, barotrauma (including subcutaneous emphysema), and miscellaneous. Device failure was defined by the inability to place and/or use the TTJV device, not patient survival., Results: Forty-four studies (428 procedures) met the inclusion criteria. Four studies included both emergency and elective procedures. Thirty studies described 132 emergency TTJV procedures; 90 were CICO emergencies. Eighteen studies described 296 elective TTJV procedures. Device failure occurred in 42% of CICO emergency vs 0% of non-CICO emergency (P<0.001) and 0.3% of elective procedures (P<0.001). Barotrauma occurred in 32% of CICO emergency vs 7% of non-CICO emergency (P<0.001) and 8% of elective procedures (P<0.001). The total number of procedures with any complication was 51% of CICO emergency vs 7% of non-CICO emergency (P<0.001) and 8% of elective procedures (P<0.001). Several reports described TTJV-related subcutaneous emphysema hampering subsequent attempts at surgical airway or tracheal intubation., Conclusions: TTJV is associated with a high risk of device failure and barotrauma in the CICO emergency. Guidelines and recommendations supporting the use of TTJV in CICO should be reconsidered., (© The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Introduction: The authors modified an adult jet ventilation injector (Hunsaker Mon-Jet Ventilation Tube(®)) to be able to provide transglottal high-frequency jet ventilation (HFJV) in small children undergoing laryngeal procedures with CO2 laser., Methods and Material: Retrospective review of the anesthetic records of all children younger than 2years undergoing transglottal HFJV for CO2 laser laryngeal procedures using this modified adult injector between 2006 and 2013., Results: Nine children (5 boys, 4 girls) were identified who underwent a total of 20 procedures. Mean age was 7.4 ± 6.9months, and mean weight was 6 ± 2.8 kg. No complications were observed with the use of HFJV or this modified injector., Conclusion: In experienced hands, this modified injector ensures excellent visibility and field access to the surgeon as well as adequate ventilation during laryngeal laser surgery in infants., (Copyright © 2016 Elsevier Inc. All rights reserved.)

We present a 54 year old female patient who had undergone a Ross procedure in 2009, and in 2013 again a replacement of the aortic root and arch with bioprothetic material and homograft replacement of the pulmonalis walve. Postoperatively the patient had experienced a functional compromising tracheal stenosis and a persistent esophago-tracheal fistula. Endoscopic attempts to close the fistula were not successful, and the fistula was "bridged" with an endoscopically positioned tracheal stent.We report the anaesthesiological management during the open surgical repair of the esophago-tracheal fistula and resection of 2 tracheal rings with high frequency jet ventilation over a period of 2.5 h. The Patient was discharged from hospital on the 17. postoperative day., (© Georg Thieme Verlag Stuttgart · New York.)

Objective: Supraglottic jet oxygenation and ventilation may provide active pulse oxygenation and ventilation in patients with respiratory suppression. This randomized controlled clinical study was designed to determine the efficacy and safety of supraglottic jet oxygenation/ventilation during monitored anesthesia care (MAC) by intravenous (IV) infusion of propofol in patients undergoing colonoscopy., Patients and Methods: Forty-nine adult patients receiving colonoscopy were randomly divided into two groups: the control group with passive oxygen supply from regular nasal cannula (N = 24) and the supraglottic jet oxygenation/ventilation (SJV) group with active pulse oxygen supply and ventilation using a manual jet ventilator (N = 25). MAC was induced and maintained by intravenous injection of propofol. HR, ECG, BP, SaO2 were continuously monitored during and 1 hour after the procedure., Results: Demographic characteristics were similar in height, weight, age and BMI (Body Mass Index) between the two groups. Compared to the control group, the SJV group had similar averaged lowest SaO2, but highest SaO2 in SJV group were significantly lower during operation (p = 0.01). The proportion of maximum chest rise movement were increased significantly in SJV group (p = 0.03) compared with control group. Demographic characteristics were similar in the times needed to use facial mask ventilation, percentage of time to maintain SaO2 above 96%, average PetCO2 during the procedure, or complications between the two groups., Conclusions: SJV can provide adequate oxygenation/ventilation during monitored anesthesia care and convenient monitoring for patients' breath, without complications.

The indications for rigid bronchoscopy for interventional pulmonology have increased and include stent placements and transbronchial cryobiopsy procedures. The shared airway between anesthesiologist and pulmonologist and the open airway system, requiring specific ventilation techniques such as jet ventilation, need a good understanding of the procedure to reduce potentially harmful complications. Appropriate adjustment of the ventilator settings including pause pressure and peak inspiratory pressure reduces the risk of barotrauma. High frequency jet ventilation allows adequate oxygenation and carbon dioxide removal even in cases of tracheal stenosis up to frequencies of around 150 min -1 ; however, in an in vivo animal model, high frequency jet ventilation along with normal frequency jet ventilation (superimposed high frequency jet ventilation) has been shown to improve oxygenation by increasing lung volume and carbon dioxide removal by increasing tidal volume across a large spectrum of frequencies without increasing barotrauma. General anesthesia with a continuous, intravenous, short-acting agent is safe and effective during rigid bronchoscopy procedures.

Background: Both superimposed high-frequency jet ventilation (SHFJV) and single-frequency (high-frequency) jet ventilation (HFJV) have been used with success for airway surgery, but SHFJV has been found to provide higher lung volumes and better gas exchange than HFJV in unobstructed airways. The authors systematically compared the ventilation efficacy of SHFJV and HFJV at different ventilation frequencies in a model of tracheal obstruction and describe the frequency and obstruction dependence of SHFJV efficacy., Methods: Ten anesthetized animals (weight 25 to 31.5 kg) were alternately ventilated with SHFJV and HFJV at a set of different fHF from 50 to 600 min. Obstruction was created by insertion of interchangeable stents with ID 2 to 8 mm into the trachea. Chest wall volume was measured using optoelectronic plethysmography, airway pressures were recorded, and blood gases were analyzed repeatedly., Results: SHFJV provided greater than 1.6 times higher end-expiratory chest wall volume than HFJV, and tidal volume (VT) was always greater than 200 ml with SHFJV. Increase of fHF from 50 to 600 min during HFJV resulted in a more than 30-fold VT decrease from 112 ml (97 to 130 ml) to negligible values and resulted in severe hypoxia and hypercapnia. During SHFJV, stent ID reduction from 8 to 2 mm increased end-expiratory chest wall volume by up to 3 times from approximately 100 to 300 ml and decreased VT by up to 4.2 times from approximately 470 to 110 ml. Oxygenation and ventilation were acceptable for 4 mm ID or more, but hypercapnia occurred with the 2 mm stent., Conclusion: In this in vivo porcine model of variable severe tracheal stenosis, SHFJV effectively increased lung volumes and maintained gas exchange and may be advantageous in severe airway obstruction.