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Recently, the demand for high-pressure and high-flow truck-mounted pumps has been increasing due to the frequent occurrence of fires in high-rise buildings. The Korean Fire Equipment Standards, which were specified by the National Fire Agency in January 2018, stipulate the performance test of high-pressure and high-flow fire pumps. In this paper, the relevance of the fire pump standard in Korean Fire Equipment Standards was evaluated by comparison and review the technical standards of domestic KFI certification, NFPA1901 in the United States and EN1028 in Europe based on the performance test of currently used truck-mounted fire pumps. Furthermore, the necessity of establishing performance test facilities for fire pumps was discussed based on the difference between the technical fire pump standards of National Fire Agency and current KFI certification to introduce accurate and safe high-pressure, high-flow fire pumps in the future.

Objective: The main objective of this study was to compare the effects of minimal and high gas flow-controlled hypotension applications on IMA and thiol/disulfide balance, which are indicators of oxidative stress.Methods: Patients undergoing elective tympanoplasty were randomized to two groups as minimal-flow and high-flow anesthesia groups. Minimal flow anesthesia was performed with 5L/min fresh gas flow reduced to 0.4 L/min. High flow was administered as 2 L/min fresh gas. Preoperative and intraoperative SpO2, StO2, EtCO2, mean arterial pressure and heart rate values were recorded. Preoperative and intraoperative IMA, total thiol, native thiol, disulfide, disulfide/native thiol and disulfide/total thiol values were recorded and compared between the two groups. Results: The mean intraoperative arterial pressure was statistically notably higher in the high flow group (p=0.048). The mean intraoperative SPO2 value was remarkably higher in the minimal flow group (p=0.032). The mean EtCO2 value was notably lower in the minimal flow group at 5 minutes and 15 minutes of the operation (p=0.029; p=0.048). The mean preoperative and intraoperative IMA values were statistically notably higher in the minimal flow group compared to the high flow group (for both, p=0.001). There was no remarkable difference between the groups in terms of the other monitored parameters (for all, p>0.05).Conclusion: IMA value was found to be significantly higher with minimal-flow anesthesia. However, no notable difference was found in terms of thiol/disulfide homeostasis, indicating the need for further comprehensive studies in order to draw a definitive conclusion

A SARS-nCoV-2 vírus okozta Covid-világjárvány megmutatta, milyen alapvető fontosságú az egészségügyi tartalékképzés, milyen fontos a Covid szempontjából kritikus egészségügyi eszközök hazai gyártókapacitásának kialakítása. A világ több országához hasonlóan a járvány kezdetekor hazánkban is megindult a szükséges védőeszközök, gyógyszerek beszerzése, a hazai gyártási kapacitás kiépítése. Az egyik kulcseszköz, a lélegeztetőgépek külföldről történő beszerzésének súlyos nehézségeire tekintettel, országunkban kormányzati segítséggel megszervezték és beindították a hazai lélegeztetőgép-gyártást. A beindult projektek egyike az amerikai alapokon nyugvó, de hazai fejlesztésű és gyártású professzionális lélegeztetőgép, a Panther 5 Vácott történő gyártósorának beindítása. A váci Celitron Kft. hónapok alatt felépítette a Panther 5, egy modern, kifinomult, a jelen orvosszakmai kihívásainak megfelelő, kipróbált lélegeztetőgép külföldi licenc alapján történő gyártási folyamatát. A Panther 5 lélegeztetőgéppel az intenzív osztályokon nemcsak a Covid-járvány támasztotta igényeknek, de a mindennapos, a járvány lecsengése utáni intenzív osztályos terápia szükségleteinek is meg tudnak felelni.A Panther 5 készülék invazív és non-invazív módon is képes lélegeztetni, emellett képes a magas áramlású nazális oxigénterápia végzésére is. Diagnosztikus képességei, speciális funkciói kiemelik a hasonló készülékek közül, lehetővé teszik, hogy a betegek állapotának felmérésével a betegek számára a legmegfelelőbb lélegeztetési módot és paramétereket lehessen kiválasztani. Magyarország sikerrel tudhatja magáénak e modern, kifinomult lélegeztetőgép-gyártási kapacitását. A kormányzat által megrendelt és legyártott ezer darab Panther 5 lélegeztetőgép összevetve a járvány elején felmért hazai intenzív osztályos lélegeztetési kapacitással, igen komoly mennyiségnek mondható. A hazai gyártósoron elkészült lélegeztetőgépek kórházak részére történő kiosztása az Állami Egészségügyi Ellátó Központon keresztül megkezdődött. A szerző kirendelt szakértőként segítette a Panther 5 hazai gyártásának megszervezését, a gép funkcióinak hazai igényeknek megfelelő adaptálását.

BACKGROUND Preoxygenation efficacy with high-flow nasal cannula (HFNC) in obese patients is not clearly established. The primary aim of this study was to compare heated, humidified, high-flow nasal cannula with face mask for preoxygenation in this population. METHODS We conducted a single-centre, randomised, controlled trial. Forty subjects with BMI ≥ 35 kg m-2 were randomly assigned to receive 5.0 min of preoxygenation with face mask and 7 cm H2 O of PEEP (PEEP group) or HFNC at 70 L min-1 (HF group). Following induction, bag-mask ventilation continued until laryngoscopy, whereas HFNC was maintained before and during intubation. The primary outcomes were end-tidal fraction of oxygen (EtO2 ) at 2.5 and 5.0 min duration of preoxygenation. Secondary outcomes included PaO2 and PaCO2 at 2.5 and 5.0 min of preoxygenation and at intubation. RESULTS Mean (±SD) EtO2 was 0.89 (±0.04) versus 0.90 (±0.05) after 2.5 min (95% CI for mean difference -0.02, 0.04) and 0.93 (±0.02) versus 0.91 (±0.02) after 5.0 min of preoxygenation (95% CI for mean difference -0.03, -0.002) in the PEEP (n = 18) and HF group (n = 20), respectively. All subjects reached an EtO2 ≥ 0.85 at 5.0 min. There were no differences in mean PaO2 or PaCO2 during preoxygenation. Subjects in the HF group had a mean (±SD) apnoea time of 199 (±38) s, but no desaturation (SpO2

This paper describes the effects of laser pulse rate and solution flow rate on the determination of lithium at high pressure for water and 2.5% sodium chloride solutions using laser-induced breakdown spectroscopy (LIBS). Preliminary studies were performed with 0–40 mg L−1 Li solutions, at ambient pressure and at 210 bar, and in static and flowing (6 mL · min−1) regimes, for a combination of four different measurement conditions. The sensitivity of calibration curves depended on the pressure and the flow rate, as well as the laser pulse rate. The sensitivity of the calibration curve increased about 10% and 18% when the pressure was changed from 1 to 210 bar for static and flowing conditions, respectively. However, an effect of flow rate at high pressure for both 2 and 10 Hz laser pulse rates was observed. At ambient pressure, the effect of flow rate was negligible, as the sensitivity of the calibration curve decreased around 2%, while at high pressure the sensitivity increased around 4% when measurements were performed in a flow regime. Therefore, it seems there is a synergistic effect between pressure and flow rate, as the sensitivity increases significantly when both changes are considered. When the pulse rate is changed from 2 to 10 Hz, the sensitivity increases 26–31%, depending on the pressure and flow conditions. For lithium detection limit studies, performed with a laser pulse energy of 2.5 mJ, repetition rate of 10 Hz, gate delay of 500 ns, gate width of 1000 ns, and 1000 accumulations, a value around 40 µg L−1 was achieved for Li solutions in pure water for all four measurement conditions, while a detection limit of about 92 µg L−1 was determined for Li in 2.5% sodium chloride solutions, when high pressure and flowing conditions were employed. The results obtained in the present work demonstrate that LIBS is a powerful tool for the determination of Li in deep ocean conditions such as those found around hydrothermal vent systems.

AIM Bronchiolitis is a common condition in the paediatric population. Severe cases often receive respiratory support with high-flow nasal cannula (HFNC). Significant variation in the application of HFNC exists throughout Australia and internationally. This study aimed to determine if the flow rate used initially and when ceasing HFNC at the end of the illness alters clinical outcomes. METHODS A retrospective analysis was conducted of 251 children less than 12 months of age when admitted to the Women's and Children's Hospital Adelaide with bronchiolitis requiring HFNC therapy between the period of April 2016 to April 2019. The primary outcome was to determine if commencing HFNC therapy at different rates (1 L/kg/min, 1.5 L/kg/min and 2 L/kg/min) affected length of stay or treatment failure (escalation in physiological parameters or respiratory support). RESULTS Treatment failure occurred in 33%, 13% and 26% of those starting at 1 L/kg/min, 1.5 L/kg/min and 2 L/kg/min, respectively. Commencing HFNC therapy at 1 L/kg/min increased length of stay by an average of 30 h (P

OBJECTIVES To determine if the implementation of a weight-based high-flow nasal cannula (HFNC) protocol for infants with bronchiolitis was associated with improved outcomes, including decreased ICU use. METHODS We implemented a weight-based HFNC protocol across a tertiary care children’s hospital and 2 community hospitals that admit pediatric patients on HFNC. We included all patients who were RESULTS Implementation of the weight-based HFNC protocol was associated with an immediate absolute decrease in ICU use of 4.0%. We also observed a 6.2% per year decrease in the slope of ICU admissions pre- versus postintervention. This was associated with an immediate reduction in median cost per bronchiolitis encounter of $661, a 2.3% immediate absolute reduction in the proportion of patients who received noninvasive ventilation, and a 3.4% immediate absolute reduction in the proportion of patients who received HFNC. CONCLUSIONS A multicenter, weight-based HFNC protocol was associated with decreased ICU use and noninvasive ventilation use. In hospitals where HFNC is used in non-ICU units, weight-based approaches may lead to improved resource use.

Flood frequency analysis should consider small and frequent floods. Despite the complexities in partial duration series implementation, it can give a better flood estimation in a way that it does not exclude any significant high flow events, even if it is not the highest event of the year. This study employs the streamflow data recorded at Kajang station, Sungai Langat, Malaysia over a 36-year period spanning from 1978 to 2013. The paper attempts to conduct flood frequency analysis using two approaches, annual maximum and partial duration series. The optimal threshold value is selected to be 48.7 m3/s, where the dispersion index stabilizes at around 1, DI = 1 . The results have shown that generalized extreme value (GEV) distribution describes the annual maximum data while the lognormal (LN3) and generalized Pareto (GPA) distribution is chosen as the best fit distribution at Kajang station for a partial duration series. There is a slight difference between estimated streamflow magnitude when using GPA and LN3 for selected return periods, while a considerable difference was observed when using annual maximum at a higher return period. As a conclusion, PDS gives more relevant magnitude estimation rather than AMS. Flood frequency plays an important role in understanding the nature and magnitude of high flow, which in turn can assist relevant agencies in the design of hydrological structures and reduce flood impacts.

Mercury is a potent neurotoxic substance and accounts for 250,000 intellectual disabilities annually. Worldwide, coastal fisheries contribute the majority of human exposure to mercury through fish consumption. Recent global mercury cycling and risk models attribute all the mercury loading to the ocean to atmospheric deposition. Nevertheless, new regional research has noted that the riverine mercury export to coastal oceans may also be significant to the oceanic burden of mercury. Here we construct an unprecedented high-spatial-resolution dataset estimating global river mercury and methylmercury exports. We find that rivers annually deliver 1,000 (minimum–maximum: 893–1,224) Mg mercury to coastal oceans, threefold greater than atmospheric deposition. Furthermore, high flow events, which are becoming more common with climate change, are responsible for a disproportionately large percentage of the export. Coastal oceans constitute 0.2% of the entire ocean volume but receive 27% of the external mercury input to the ocean. We estimate that the river mercury export could be responsible for a net annual export of 350 (interquartile range: 52–640) Mg mercury across the coastal–open-ocean boundary, although there is still high uncertainty around this estimate. Our results show that river export is the largest source of mercury to coastal oceans worldwide, and continued mercury risk modelling should incorporate the impact of rivers. Rivers transport about 1,000 Mg mercury annually to coastal oceans, which is threefold greater than the amount delivered by atmospheric deposition, according to a global analysis of mercury measurements in rivers.

High flow nasal cannula (HFNC) therapy is a non-invasive oxygen delivery mode which is safe and well tolerated by adults and children with respiratory distress. HFNC is increasingly used in children with respiratory distress due to mucus retention, such as bronchiolitis and acute asthma. However, he effectiveness of this therapy in acute asthma has not been well researched. To evaluate HFNC for acute childhood asthma, we designed a randomized prospective crossover trial. In the trial, children aged 6–18 years, with a forced expiratory volume in one second (FEV1) lability of ≥30% during an exercise challenge test (ECT) are included. The time of fully recovered lung function within 10% of the baseline after peak fall of FEV1 is compared with and without HFNC therapy. A 50% reduction of recovery time during HFNC therapy compared to recovery time without HFNC is considered clinically relevant, with a power of 80% and a significance level of 5%. Secondly, the pressure used by the HFNC device to deliver the constant present flow is evaluated. A relationship between the measured pressure and the degree of recovery may reveal a working mechanism behind HFNC.

One of the solutions to increase children's energy intake is the use of amylase-rich flours. This led us to optimize the fluidification capacity of two paddy rice varieties. For that, the Doehlert plane-type response surface methodology was used to optimize the germinating ability of paddy rice flour (varieties Nerica 3 and Nerica L56) to fluidize cassava-based gruels by using two factors: soaking and germination time. The evaluated response was the flow velocity of the gruels. The optimization result showed that, the optimal soaking time was 48 h for the variety Nerica L56 and 12 h for Nerica 3. Concerning the optimal germination time, it was 135 h for both varieties. These conditions have been found to have the best fluidifying capacities for cassava flour-based gruels. The incorporation of 3 g germinated paddy rice flour (Nerica L56 and Nerica 3) and at optimal conditions, allowed us to obtain high flow velocities of the gruels. They were 100.00 mm/30 s and 210.66 mm/30 s respectively for the varieties Nerica L56 and Nerica 3. These flow velocities were similar to the flow velocities predicted by the model for desirabilities of 0.99 and 1.00. In view of all these results, we could therefore recommend the use of these two varieties of rice produced under these conditions to improving flow velocities, dry matter concentrations and energy bulk of the gruels. GRAPHIC ABSTRACT: [Image: see text]

BackgroundContinuous positive airway pressure (CPAP) and high-flow nasal oxygen (HFNO) have been used to manage hypoxaemic respiratory failure secondary to coronavirus disease 2019 (COVID-19) pneumonia. Limited data are available for patients treated with noninvasive respiratory support outside of the intensive care setting.MethodsIn this single-centre observational study we observed the characteristics, physiological observations, laboratory tests and outcomes of all consecutive patients with COVID-19 pneumonia between April 2020 and March 2021 treated with noninvasive respiratory support outside of the intensive care setting.ResultsWe report the outcomes of 140 patients (mean±sd age: 71.2±11.1, 65% male (n=91)) treated with CPAP/HFNO outside of the intensive care setting. Overall mortality was 59% and was higher in those deemed unsuitable for mechanical ventilation (72%). The mean age of survivors was significantly lower than those who died (66.1 versus 74.4 years, pversus 4, pConclusionsCPAP and HFNO delivered outside of the intensive care setting are viable treatment options for patients with hypoxaemic respiratory failure secondary to COVID-19 pneumonia, including those considered unsuitable for invasive mechanical ventilation. This provides an opportunity to safeguard intensive care capacity for COVID-19 patients requiring invasive mechanical ventilation.

High-flow nasal cannula is a non-invasive ventilation system that was introduced as an alternative to continuous positive airway pressure), with a marked increase in its use in pediatric care settings. However, the expected budget impact of this intervention has not been explicitly estimated. This study aimed to evaluate the budget impact of the high-flow nasal cannula for acute bronchiolitis in Colombia.A budget impact analysis was performed to evaluate the potential financial impact deriving from high-flow nasal cannula during 2020. The analysis considered a 5-year time horizon and Colombian National Health System perspective. The incremental budget impact was calculated by subtracting the cost of the new treatment, in which a high-flow nasal cannula is reimbursed, from the cost of the conventional treatment without a high-flow nasal cannula (supplemental oxygen through a nasal cannula up to a maximum of 2 liters per minute). Univariate one-way sensitivity analyses were performed.In the base-case analysis the 5-year costs associated with high-flow nasal cannula and no- high-flow nasal cannula were estimated to be US$159,585,618 and US$172,751,689 respectively, indicating savings for Colombian National Health equal to US$13,166,071 if the high-flow nasal cannula is adopted for the routine management of patients with acute bronchiolitis. This result was robust in univariate sensitivity one-way analysis.High-flow nasal cannula was cost-saving in emergency settings for treating infants with acute bronchiolitis. This evidence can be used by decision-makers in our country to improve clinical practice guidelines and should be replicated to validate their results in other middle-income countries.

Purpose The use of high-flow oxygen via nasal cannula has become increasingly more common in various patient populations given the multiple benefits for treating respiratory distress and failure. There is emerging, though varying research on the impact high-flow oxygen delivery may have on adult oropharyngeal swallowing function. The purpose of this literature review is to outline available research and examine study design, populations investigated, findings, and clinical considerations of these findings. Method After an extensive online database search, we found five available peer-reviewed research articles specifically investigating oropharyngeal swallowing function in adults receiving high-flow nasal cannula (HFNC) therapy. Each article was reviewed and summarized in detail with close attention paid to results and clinical implications. Limitations, indirectness, and/or methodologic flaws are highlighted for the readers' consideration. Conclusions Four prospective design studies and one retrospective data analysis collection have been published evaluating the effects of high-flow oxygen therapy on adult oropharyngeal swallowing. Three of the prospective design studies evaluated healthy adults; one prospective design and the retrospective analysis data collection investigated acute care patients requiring HFNC. Study findings varied greatly likely due to variability of each study's subject population, design, and methods. Variability of results may make it challenging for speech pathologists attempting to use evidence-based decision making in clinical practice. Additional studies investigating nonhealthy subjects undergoing instrumental swallow studies while on HFNC are warranted.

High flow nasal oxygen (HFNO) therapy has been widely used in intensive care units (ICU); however, its efficacy remains inconclusive. This systematic review and meta-analysis aimed to compare the efficacy of HFNO therapy with th at of alternative noninvasive oxygen therapies such as conventional oxygen therapy (COT) and noninvasive ventilation (NIV) in ICU.A Pubmed, Embase, Web of Science, Cochrane Library database search was performed in March 2020.In adult patients in ICU, HFNO may improve oxygenation and decrease pneumonia rate without affecting the length of ICU stay, intubation or reintubation rate, mortality, and SpO₂ at the end of oxygen therapy.

Therapeutic hypothermia (TH) is one of the few proven neuroprotective modalities in clinical practice. However, current methods to achieve TH are suboptimal. We investigated a novel esophageal device that utilizes high-flow transesophageal dry air to achieve TH via evaporating cooling. Seven Yorkshire pigs (

The purpose of this study was to determine whether the plethysmographic variability index ("PVi") can predict preload responsiveness in patients with nasal high flow (NHF) (≥30 L/min) with any sign of hypoperfusion. "Preload responsiveness" was defined as a ≥10% increase in stroke volume (SV), measured by transthoracic echocardiography, after passive leg raising. SV and PVi were reassessed in preload responders after receiving a 250-mL fluid challenge. Twenty patients were included and 12 patients (60%) were preload responders. Responders showed higher baseline mean PVi (24% vs. 13%

Head and neck arteriovenous malformations are the commonest extracranial vascular malformations but demonstrate a unique challenge in the limited available surgical options secondary to their intimate association to vital structures. We present a case of middle-aged female patient who presented with threatened upper-airway obstruction and bleeding secondary to a slowly enlarging parapharyngeal arteriovenous malformations. She was treated with an endovascular-only approach with the proximal arteriole branches selectively undergoing embolo-sclerotherapy with an optimal radiological and clinical outcome. We also demonstrate the utility of elective tracheostomy prior to intervention.

BACKGROUND: There is a persistent concern over the risk of respiratory pathogen transmission, including SARS-CoV-2, via the formation of aerosols (ie, a suspension of microdroplets and residual microparticles after evaporation) generated during high-flow nasal cannula (HFNC) oxygen therapy in critically ill patients. This concern is fueled by limited available studies on this subject. In this study, we tested our hypothesis that HFNC treatment is not associated with increased aerosol formation as compared to conventional oxygen therapy. METHODS: We used laser light scattering and a handheld particle counter to detect and quantify aerosols in healthy subjects and in adults with acute respiratory disease, including COVID-19, during HFNC or conventional oxygen therapy.RESULTS: The use of HFNC was not associated with increased formation of aerosols as compared to conventional oxygen therapy in both healthy subjects (n = 3) and subjects with acute respiratory disease, including COVID-19 (n = 17).CONCLUSIONS: In line with scarce previous clinical and experimental findings, our results indicate that HFNC itself does not result in overall increased aerosol formation as compared to conventional oxygen therapy. This suggests there is no increased risk of respiratory pathogen transmission to health care workers during HFNC.

Purpose Compare the efficacy(reintubation rate) between a high-flow nasal cannula(HFNC) and the WhisperFlow CPAP system in patients at risk for postextubation failure. Material and methods RCT was conducted in patients who had at least one high-risk criterion for postextubation failure. All patients were randomly assigned to CPAP or HFNC for 48 h. Results Of 140 patients, sixty-nine were assigned to the CPAP group and 71 to the HFNC group. The reintubation rate was similar between the HFNC and WhisperFlowCPAP [5 cases(7.0%) vs. 6 cases(8.7%); P = 0.76]. The postextubation respiratory failure rate was not significantly different between the HFNC and WhisperFlow CPAP groups [10 cases(14.1%)vs.7cases(10.1%); P = 0.48]. The respiratory rate was lower in the HFNC than CPAP group(P = 0.04). The pain rating scale score was lower in the HFNC group than in the WhisperFlow CPAP group at 24 h (2.8 ± 2.0 vs. 3.7 ± 1.9, P = 0.02) and 48 h (2.8 ± 1.8 vs. 3.8 ± 1.9, P = 0.002). Conclusions We are unable to demonstrate a reduction in postextubation respiratory failure in at risk patients with the use of HFNC compared with the WhisperFlow CPAP system probably because small sample size, but HFNC was better tolerated.

BACKGROUND Since the outbreak of coronavirus disease 2019 (COVID-19) in Wuhan, China in December 2019, the overall fatality rate of severe and critical patients with COVID-19 is high and the effective therapy is limited. CASE SUMMARY In this case report, we describe a case of the successful combination of the prone position (PP) and high-flow nasal oxygen (HFNO) therapy in a spontaneously breathing, severe COVID-19 patient who presented with fever, fatigue and hypoxemia and was diagnosed by positive throat swab COVID-19 RNA testing. The therapy significantly improved the patient's clinical symptoms, oxygenation status, and radiological characteristics of lung injury during hospitalization, and the patient showed good tolerance and avoided intubation. Additionally, we did not find that medical staff wearing optimal airborne personal protective equipment (PPE) were infected by the new coronavirus in our institution. CONCLUSION We conclude that the combination of PP and HFNO could benefit spontaneously breathing, severe COVID-19 patients. The therapy does not increase risk of healthcare workers wearing optimal airborne PPE to become infected with virus particles.

ObjectivesHigh-flow nasal cannula (HFNC) oxygen therapy has become a common treatment for respiratory conditions in children. To our knowledge, no study has described practice patterns for HFNC on pediatric inpatient wards in Canada. The aim of this study was to survey current practices and policies regarding the use of HFNC on the ward in children’s hospitals in Canada.MethodsWe conducted a web-based survey of Pediatric Hospital Medicine section chiefs in major tertiary care hospitals in Canada. The primary outcome was the proportion of hospitals that use HFNC on the general pediatric ward. Secondary outcomes included indications for HFNC, initial and maximum flow rates, maximum FiO2, method of nutrition delivery while on HFNC, level of nursing and respiratory therapist care required, criteria for pediatric intensive care unit transfer, and subjective successes and challenges of implementing a ward-based HFNC policy.ResultsThe section chief survey response rate was 100% (15/15). Eight centres (53%) allowed the use of HFNC outside of an intensive care setting. Six centres initiated HFNC on the ward, while two centres only accepted patients after HFNC had been initiated in an intensive care setting. Other practices and policies varied considerably from centre to centre.ConclusionOur study reveals that approximately half of tertiary children’s hospitals in Canada currently use HFNC on the ward and utilize a range of practices and policies. Other centres are considering implementation. Further research is needed to inform best practices for HFNC therapy, support stewardship of health care resources, and promote safe patient care.

BACKGROUND: High-flow nasal cannula (HFNC) has been used in the treatment of pediatric asthma, although high-quality data comparing HFNC to aerosol mask nebulizer are lacking. We hypothesized that HFNC would perform similarly to the aerosol mask for meaningful clinical outcomes in children with critical asthma. METHODS: We retrospectively reviewed the medical records of children with critical asthma (age 2–17 y) with a modified pulmonary index score (MPIS) ≥ 8 admitted to our pediatric ICU as part of a quality improvement project. Patients were managed with our MPIS-based, respiratory therapist-driven protocol. Subjects were divided into 2 cohorts by initial respiratory support: HFNC or aerosol mask. Data included demographics, initial respiratory support, and MPIS over time. Primary outcome was hospital length of stay (LOS). Secondary outcome was difference in MPIS over time. RESULTS: We included 171 subjects, with 104 in the HFNC group and 67 in the aerosol mask group. Median (interquartile range [IQR]) age was lower in the HFNC group (5 [IQR 4–9] vs 7 [IQR 5–10] y, P = .006)], while other demographic characteristics were similar. Initial MPIS was similar between HFNC and aerosol mask groups (11 [IQR 9–12] vs 10 [IQR 9–12], P = .15). There were no significant differences for hospital LOS (2.9 [IQR 2.1–3.9] vs 3.0 [IQR 2.3–4.4] d, P = .47), pediatric ICU LOS (1.9 [IQR 1.4–2.8] vs 1.8 [IQR 1.5–3.0] d, P = .92), or time to MPIS CONCLUSIONS: HFNC performed similarly to aerosol mask in pediatric patients with critical asthma.

Background: High-flow arteriovenous fistulae (HF-AVF) may lead to adverse cardiac remodeling in hemodialysis patients. We have investigated whether a novel external stent is safe and effective in reducing and stabilizing flow rates during a 1-year follow-up after HF-AVF reconstruction. Methods: All patients with HF-AVF (access flow rate ⩾ 1500 ml/min), who underwent HF-AVF reconstruction with external stenting in two centers between June 2018 and May 2020, were included in this retrospective analysis. During HF-AVF reconstruction, the dilated vein segment was resected, underwent volume reduction, and was externally stabilized using a braided cobalt-chromium external stent. AVF flow rates were assessed preoperatively, intraoperatively, and at follow up visits using duplex ultrasound. Results: Forty-three HF-AVFs in 42 patients were reconstructed and supported with an external stent (mean age 49 years, range 20–86 years; 74% men). Fifty-one percent were forearm AVFs, 49% were upper arm. The mean preoperative flow rate was 2622 ± 893 ml/min (range: 1500–6000 ml/min) and was decreased to 710 ± 221 ml/min (range: 300–1300 ml/min) intra-operatively after HF-AVF reconstruction. At 6 and 12-months follow-up, the mean flow rates were 1132 ± 320 ml/min (range: 470–1700 ml/min) and 1453 ± 888 ml/min (range: 300–3800 ml/min), respectively. Recurrence of high flow (>1500 ml/min) occurred in 16% and 25% of the patients at 6 and 12 months and primary patency rates were 86% and 70%, respectively. Conclusions: This early experience with novel external stenting for HF-AVF reconstruction demonstrates that it is a safe and effective method for reducing and stabilizing flow rates up to 1-year post procedure. Additional studies are required to evaluate the durability of this procedure over the longer term and assess its effect on cardiac remodeling.

Thermo-humidified nasal high flow (NHF) oxygen therapy is increasingly used in the management of respiratory failure. This therapy has recently gained attention as an alternative non-invasive respiratory support in several clinical scenarios, including acute and chronic settings. NHF enhances the patient's comfort and tolerance when compared with standard oxygen by supplying a heated and humidified mixture of air and oxygen at flows up to 60L/min. It can be delivered through different devices. Although few studies have compared the clinical effects of different NHF systems, the purpose of this paper is to describe the major benefits of NHF and to provide a quick guide on how to implement this therapy in daily practice. We have also included a brief description of the most frequently used NHF systems.

The measurement of discharge plays an important role in the design of open channels. Direct measurements of discharges in large canals and rivers are not feasible because of high flow. Weirs are the most widely used discharge-measuring device for open channels. In this study, the experimental study along with the modeling of discharge through a sharp-crested triangular weir using ANN model has been conducted. The sharp-crested triangular weirs having apex angles 30°, 45°, 60°, 75°, 90° and weir heights 15 cm, 18 cm, and 20 cm have been used in this study. The experiments were conducted for each combination of weir angle and weir height. The head above the weir crest was measured for all such combinations of apex angles and weir heights for different discharges. These experimental data are then used to train the ANN model to predict the discharge over a sharp-crested triangular weir. The Levenberg–Marquardt algorithm has been used as training algorithm. The MSE and R have been used as statistical parameters to judge the performance of ANN model. The ANN model terminates after 18 epochs and the MSE obtained for training, validation and testing are 8.477e − 08, 1.471 e − 07 and 1.325 e − 07, respectively. The corresponding R values obtained for training, validation and testing are 0.9987, 0.9973 and 0.9962, respectively. It was also observed that the predicted discharge stays within the range of ± 5% of the experimental discharge value. The model performance results are encouraging and conclusive and the developed ANN model may be used to predict the discharge over sharp-crested triangular weir precisely.

OBJECTIVES: We aimed to reduce unnecessary use of high-flow nasal cannula (HFNC) at lower flow rates through the implementation of a standard daily trial off HFNC at a medium-sized academic center. METHODS: We used an interprofessional quality improvement collaboration to develop and implement interventions to reduce HFNC waste in children aged 1 month to 24 months with bronchiolitis who were admitted to the inpatient ward or ICU. Key interventions included development and implementation of the Simple Cannula/Room Air Trial for Children (SCRATCH Trial), a standard trial off HFNC for eligible infants. Process measures were selected as metrics of use of the newly developed trial. The primary outcome measure was hours of treatment with ≤8 L per minute (LPM) of HFNC. Additional outcome measures included total hours of treatment with HFNC and length of stay. RESULTS: A total of 271 patients were included in this study, 131 in the preimplementation group and 140 in the postimplementation group. The mean hours of treatment below our a priori determined waste line (≤8 LPM of HFNC) decreased from 36.3 to 16.8 hours after SCRATCH Trial implementation, and mean length of stay decreased from 4.1 to 3.0 days. CONCLUSIONS: The SCRATCH Trial was successfully implemented across hospital units, with a significant reduction in hours on ≤8 LPM of flow. Rapid discontinuation of HFNC appears feasible and may be associated with a shorter length of stay.

Retrogressive erosion is a high-speed erosion process that usually occurs during the rapid release of stored water in reservoirs built on sandy rivers. Retrogressive erosion has been utilized in the practice of reservoir sedimentation control, but accurate prediction of the bed deformation process by numerical models has rarely been reported. The current study presents a one-dimensional morphodynamic model for simulating the evolution process of retrogressive erosion induced by high-velocity flows on steep slopes. The governing equations apply a Cartesian coordinate system with a vertically oriented z axis. The bed surface gradient and friction terms in the flow equations include correction factors to take account of the effects of high slope on flow movement. The net vertical sediment flux term in the sediment transport and bed deformation equations is calculated using an equation of erosion velocity. Particularly, this equation is based on an empirical relation between the sediment entrainment rate and the Shields parameter in contrast to the traditional sediment transport capacity, and the critical Shields parameter is modified by taking into account the permeability of the sediment layer and the stability of particles on a slope. The feedback of scoured sediment on the flow movement is considered by additional terms in the governing equations. Flume experiments of retrogressive erosion in literature were simulated to validate the model. The temporal variations of the longitudinal profiles of the free surface and channel bed and the sediment transport rate were well predicted. The algorithm calculating sediment entrainment in the proposed model also was validated for an experiment measuring entrainment rate from the literature. More importantly, it was found that the morphodynamic model using the sediment transport capacity equation predicts the trend of cumulative erosion contrary to the measurements, while results of the proposed model can follow a similar trend with the observed data in the retrogressive erosion process.

Rationale: How to provide advanced respiratory support for coronavirus disease (COVID-19) to maximize population-level survival while optimizing mechanical ventilator access is unknown. Objectives: To evaluate the use of high-flow nasal cannula for COVID-19 on population-level mortality and ventilator availability. Methods: We constructed dynamical (deterministic) simulation models of high-flow nasal cannula and mechanical ventilation use for COVID-19 in the United States. Model parameters were estimated through consensus based on published literature, local data, and experience. We had the following two outcomes: 1) cumulative number of deaths and 2) days without any available ventilators. We assessed the impact of various policies for the use of high-flow nasal cannula (with or without “early intubation”) versus a scenario in which high-flow nasal cannula was unavailable. Results: The policy associated with the fewest deaths and the least time without available ventilators combined the use of high-flow nasal cannula for patients not urgently needing ventilators with the use of early mechanical ventilation for these patients when at least 10% of ventilator supply was not in use. At the national level, this strategy resulted in 10,000–40,000 fewer deaths than if high-flow nasal cannula were not available. In addition, with moderate national ventilator capacity (30,000–45,000 ventilators), this strategy led to up to 25 (11.8%) fewer days without available ventilators. For a 250-bed hospital with 100 mechanical ventilators, the availability of 13, 20, or 33 high-flow nasal cannulas prevented 81, 102, and 130 deaths, respectively. Conclusions: The use of high-flow nasal cannula coupled with early mechanical ventilation when supply is sufficient results in fewer deaths and greater ventilator availability.

The appropriate identification and localization of a nidus of a high flow arteriovenous malformation is crucial to guide targeted interventional therapy. However, the nidus of a complex or previously treated HFAVM can be difficult to non–invasively demonstrate on magnetic resonance imaging alone. We describe a unique case of a 56-year-old female with a complex high flow arteriovenous malformation in which we demonstrated the feasibility of fluorodeoxyglucose positron emission tomography/computed tomography to non–invasively delineate the nidus which subsequently guided successful targeted interventional therapy.

BACKGROUND: Studies of pulmonary denitrogenation (pre-oxygenation) in obstetric populations have shown high flow nasal oxygen therapy (HFNO) is inferior to facemask techniques. HFNO achieves median end-tidal oxygen fraction (FE′O(2)) of 0.87 after 3 min. As HFNO prolongs safe apnoea times through apnoeic oxygenation, we postulated that HFNO would still extend safe apnoeic times despite the lower FE′O(2) after pre-oxygenation. METHODS: The Interdisciplinary Collaboration in Systems Medicine simulation suite, a highly integrated, high-fidelity model of the human respiratory and cardiovascular systems, was used to study the effect of varying FE′O(2) (60%, 70%, 80%, and 90%) on the duration of safe apnoea times using HFNO and facemask techniques (with the airway open and obstructed). The study population consisted of validated models of pregnant women in active labour and not in labour with BMI of 24, 35, 40, 45, and 50 kg m(−2). RESULTS: HFNO provided longer safe apnoeic times in all models, with all FE′O(2) values. Labour and increased BMI reduced this effect, in particular a BMI of 50 kg m(−2) reduced the improvement in apnoea time to 1.8–8.5 min (depending on the FE′O(2)), compared with an improvement of more than 60 min in the subject with BMI 24 kg m(−2). CONCLUSIONS: Despite generating lower FE′O(2), HFNO provides longer safe apnoea times in pregnant subjects in labour. Care should be taken when used in patients with BMI ≥50 kg m(−2) as the extension of the safe apnoea time is limited.

La cánula nasal de alto flujo (CNAF) es una alternativa en la oxigenoterapia de pacientes en insuficiencia respiratoria aguda hipoxémica, especialmente en contexto de pandemia por SARS-CoV-2. Existen muchos beneficios, con distintos niveles de evidencia y muy pocos efectos adversos reportados a su uso descritos en adultos. Se presenta el caso de un paciente con enfermedad pulmonar obstructiva crónica, que cursando con una neumonía grave por SARS-CoV-2, mientras recibía terapia con CNAF, desarrolló un neumotórax. Esta complicación asociada a la terapia con CNAF es poco reportada en la literatura, lo que motiva este reporte.

Bricks-and-mortar retailers have recently begun to utilize mobile applications delivering location-based services (LBS) as part of their omni-channel strategy to provide consumers with new in-store experiences. In light of this trend, this study examined how consumers’ value perception influences their intention to use LBS in the store and their behavioral responses as well as the moderating effect of flow on the relationships between the perceived benefits/costs and the perceived value of LBS usage. The results indicated that benefits (perceived usefulness and perceived enjoyment) and costs (perceived complexity and perceived privacy risk) were influential antecedents shaping consumers’ value perception of LBS, which in turn impacted their intention to use LBS and behavioral responses (search and purchasing using LBS). Also, we found that the negative relationship between the perceived costs and perceived value was attenuated in high flow states than in low flow states

The object of research in this article is the productive deposits of the pre-Jurassic complex. The pre-Jurassic complex is of great interest, this is an unconventional reservoir with a complex structure and developed fractured zones. High flow rates cannot be determined by the rock matrix, since the matrix permeability coefficient is on average 2−3 md. In this regard, there is the problem of separation of fractured intervals according to a standard set of well testing.

There is a need to develop safe and effective downstream passage for diadromous anguillid eels on large rivers, where the combination of physical screening and bypass structures that is used to protect eel on smaller rivers is infeasible. The Eel Passage Research Center was established in 2013 to address the challenge of providing safe passage for out-migrating silver-stage American eel (Anguilla rostrata) on the St. Lawrence River, the outflow of the Laurentian Great Lakes, which is spanned by two large, mainstem hydroelectric generating stations. The Center's goal is to develop the technology to behaviorally guide eel to a collection point for capture and transfer around the two generating stations. To achieve this goal, three parallel initiatives were undertaken; 1) research into behavioral guidance techniques suitable for guiding out-migrating eel on large, high flow rivers, 2) the evaluation of sonar technologies for detection of eel, necessary for assessing in situ guidance, and 3) the commissioning of literature reviews for the most promising guidance technologies. A number of behavioral guidance stimuli, including electricity, flow, sound and electromagnetic fields were examined in laboratory and flume settings for their utility in guiding out-migrating silver-stage eel. Of the techniques examined, only sound showed any promise for guidance. Three sonar technologies (Simrad 120 kHz EK60 echosounder, Sound Metrics ARIS Explorer 1800 sonar, and the Kongsberg Mesotech 500 kHz M3 multi-mode multibeam sonar) were evaluated to determine if existing acoustic technologies could be used to estimate the relative abundance and distribution of out-migrating silver-phase American eel in the St. Lawrence River. Only the ARIS unit could successfully identify eel targets, and only over a short (

Respiratory support is applied to maintain adequate oxygenation and ventilation and hence supplemental oxygenation is the first line of treatment for hypoxemic respiratory failure. There are multiple conventional oxygen support devices. However, in majority of these, oxygen provided is not humidified and maximum flow rate is 15l/min. However, high flow nasal oxygen (HFNO) is an alternative to conventional oxygen therapy. It is a technique that delivers heated and humidified oxygen with a controlled fraction of inspired oxygen(FiO2) at a maximum flow rate of 60L/min via (1) a specialized nasal cannula

AIM To assess cerebral oxygenation in premature infants who are transitioning from nasal continuous positive airway pressure (nCPAP) to heated humidified high-flow nasal cannula therapy (HFNC). METHODS A prospective observational study done in a single-centre neonatal intensive care unit (NICU). Regional cerebral oxygen saturations (RcSO2 ) were measured using frequency-domain near-infrared spectroscopy (FD-NIRS) in very low birthweight (VLBW) premature infants born at

This study aimed to assess how the emergence of high-flow nasal cannula (HFNC) has modified the demographic and clinical characteristics as well as outcomes of infants with bronchiolitis admitted to a pediatric intensive care unit (PICU).This was a single-center retrospective study including infants aged 1 day to 6 months with bronchiolitis requiring HFNC, noninvasive ventilation (NIV), or invasive ventilation on admission.A total of 252 infants (mean age 53±36 days) were included in the study. The use of HFNC increased from 18 (21.4%) during 2013-2014 to 53 infants (55.2%) during 2015-2016. The length of stay in the PICU decreased over time from 4.7±2.9 to 3.5±2.7 days (P0.01) but the hospital length of stay remained similar (P=0.17). On admission, patients supported by HFNC as the first-line therapy were older. The PICU length of stay was similar according to the type of respiratory support (P=0.16), but the hospital length of stay was longer for patients supported by HFNC (P=0.01).The distribution of respiratory support has significantly changed over time for patients with bronchiolitis and HFNC is increasingly used. The demographic and clinical characteristics of the have not changed over time. However, the PICU length of stay decreased significantly.

High-flow tracheal oxygenation (HFTO), a modification of high-flow nasal cannula (HFNC), has been used in tracheostomized patients but only rarely for weaning. We present two cases on prolonged mechanical ventilation (PMV) where HFTO assisted weaning. How to cite this article Ramachandran L, Jha OK, Sircar M. High-flow Tracheal Oxygenation: A New Tool for Difficult Weaning. Indian J Crit Care Med 2021;25(2):224–227.

Background The role of high flow nasal oxygenation (HFNO) for pre-oxygenation before obstetric general anaesthesia remains unclear. This study aimed to determine the number of vital capacity breaths using HFNO required to pre-oxygenate 90% of parturients to an end-tidal oxygen concentration fraction (FETO2) of ≥0.90 (termed EN90). Methods Using up-down, sequential allocation trial design, volunteer term parturients undergoing caesarean delivery were investigated with HFNO with their mouth closed, followed by mouth open, and if FETO2 ≥0.90 was not achieved after a maximum of 20 vital capacity breaths, pre-oxygenation was attempted with a face mask. The primary outcome was the number of vital capacity breaths required using HFNO (mouth open and closed) to achieve EN90. Secondary outcomes included assessment of EN90 using mouth open versus mouth closed and face mask pre-oxygenation, maternal satisfaction and evaluation of fetal cardiotocography. Results Twenty women at term were recruited. Successful pre-oxygenation occurred in 4 (20%), 3 (15%) and 14 (70%) women with HFNO mouth closed, HFNO mouth open, and via face mask respectively. At up to 20 vital capacity breaths, face mask pre-oxygenation was more successful at achieving EN90 compared with both HFNO with a closed (P=0.006) or open (P=0.001) mouth. Closed mouth HFNO did not outperform open mouth pre-oxygenation. Conclusion Face mask pre-oxygenation is more effective at achieving EN90 compared with to HFNO within a clinically acceptable number of vital capacity breaths. Further studies are needed to determine the role of HFNO in optimising the time before desaturation and for apnoeic oxygenation in term parturients.

Purpose: The aim of this study was to report our experience in one casepre-operative embolization of high-flow peripheral arteriovenous malformations (AVMs) using plug and push technique with low-density NBCA/LIPIODOL. Case presentation: A patient 26 years old man hospitalized at Hue Central Hospital, Vietnam with big pulsatile mass at right femoral above the knee. Doppler ultrasound showed a mass with high systolic and diastolic velocities. Patient felt discomfort and he has a desire to resolve this condition. Angiogram showed a large and high-flow arteriovenous malformation type IV according to Yakes classification. A multidisciplinary discussion was required between surgeon and interventionist because of the high risk of in-operative hemorrhage. Patient was treated with low-density NBCA/LIPIODOL 12.5% embolic agents by transarterial approach using plug and push technique before surgical excision. Results: Technical success was achieved in this patient. Complete devascularization was obtained and surgical excision was performed at 4 days after embolization procedure. Non-target NBCA/LIPIODOL embolization was not observed. Conclusions: Embolization using plug and push technique with low-density NBCA/LIPIODOL is an promising and interesting option for management of peripheral high-flow AVMs either pre-operatively or as a single treatment.

Background. High flow tracheostomy (HFT) is a commonly used weaning and humidification strategy for tracheostomised patients, but little is known as to how much PEEP or mechanical benefit it offers. Patient anatomy and device characteristics differentiate it from high flow nasal cannula and the physiological effects observed. Objectives. (1) To review the available literature on the effects of HFT on airway pressure and indices of gas exchange. (2) To quantify PEEP generated by a HFT circuit. Methods. A randomised benchtop experiment was conducted, with a size 8 uncuffed Portex tracheostomy connected to an Optiflow™ with Airvo 2™ humidifier system. The tracheostomy tube was partially immersed in water to give rise to a column of water within the inner surface of the tube. An air fluid interface was generated with flows of 40 L/min, 50 L/min, and 60 L/min. The amount of potential PEEP (pPEEP) generated was determined by the distance the water column was pushed downward by the flow delivered. Findings. Overall 40 L/min, 50 L/min, and 60 L/min provided pPEEP of approximately 0.3 cmH2O, 0.5 cmH2O, and 0.9 cmH2O, respectively. There was a statistically significant change in pPEEP with change in flows from 40–60 L/min with an average change in pPEEP of 0.25–0.35 cmH2O per 10 L/min flow ( p value

Acute respiratory failure (ARF) in immunocompromised patients is associated with increased incidence of mortality when endotracheal intubation is used. Early use of high flow nasal cannula (HFNC) o...