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The shortage of available organ donors is a significant problem worldwide, and various efforts have been carried out to avoid the loss of potential organ donors. Among them, organ donation from cardiocirculatory deceased donors (DCD), in which withdrawal of life-sustaining therapies is ongoing (Maastricht type III donors), is one emerging strategy. Thanks to the latest advances in transplantation and organ preservation, such as normothermic regional perfusion (NRP), ex vivo perfusion techniques, and good organization and communication among prehospital care providers, emergency departments, intensive care units, and transplantation units, DCD is rapidly increasing; it’s estimated that it will increase the number of donations of lungs and splanchnic organs by more than 40%. Although Maastricht type II DCD requires a 24/7 available experienced extra corporeal membrane oxygenation (ECMO) team in the institution, Maastricht DCD type III could be organized in secondary care and spoke hospitals without in loco ECMO facilities for NRP. This article analyses a potential mobile team organization based on the hub-and-spoke model, which already exists and functions in Italy, by estimating the dimension of the controlled DCD phenomenon in Italy, coordination requirements, costs, personnel training, and education, and reporting a single center experience in Milan, Italy.

It is not known if the degrees of improvement in oxygenation obtained by CPAP can predict clinical outcomes in patients with COVID-19 pneumonia. This was a retrospective study conducted on patients with severe COVID-19 pneumonia treated with CPAP in three University hospitals in Milan, Italy, from March 2020 to March 2021. Arterial gas analysis was obtained before and 1 h after starting CPAP. CPAP failure included either death in the respiratory units while on CPAP or the need for intubation. Two hundred and eleven patients (mean age 64 years, 74% males) were included. Baseline median PaO2, PaO2/FiO2 ratio (P/F), and the alveolar-arterial (A-a) O2 gradient were 68 (57–83) mmHg, 129 (91–179) mmHg and 310 (177–559) mmHg, respectively. Forty-two (19.9%) patients died in the respiratory units and 51 (24.2%) were intubated. After starting CPAP, PaO2/FiO2 increased by 57 (12–113; p < 0.001) mmHg, and (A-a) O2 was reduced by 68 (−25–250; p < 0.001) mmHg. A substantial overlap of PaO2, P/F, and A-a gradient at baseline and during CPAP was observed in CPAP failures and successes; CPAP-associated improvements in oxygenation in both groups were similar. In conclusion, CPAP-associated improvements in oxygenation do not predict clinical outcomes in patients with severe COVID-19 pneumonia.

PURPOSE: The study aimed to develop a gastrointestinal (GI) dysfunction score predicting 28-day mortality for adult patients needing mechanical ventilation (MV). METHODS: 377 adult patients from 40 ICUs with expected duration of MV for at least 6 h were prospectively studied. Predefined GI symptoms, intra-abdominal pressures (IAP), feeding details, organ dysfunction and treatment were documented on days 1, 2, 4 and 7. RESULTS: The number of simultaneous GI symptoms was higher in nonsurvivors on each day. Absent bowel sounds and GI bleeding were the symptoms most significantly associated with mortality. None of the GI symptoms alone was an independent predictor of mortality, but gastrointestinal failure (GIF)--defined as three or more GI symptoms--on day 1 in ICU was independently associated with a threefold increased risk of mortality. During the first week in ICU, GIF occurred in 24 patients (6.4%) and was associated with higher 28-day mortality (62.5 vs. 28.9%, P = 0.001). Adding the created subscore for GI dysfunction (based on the number of GI symptoms) to SOFA score did not improve mortality prediction (day 1 AUROC 0.706 [95% CI 0.647-0.766] versus 0.703 [95% CI 0.643-0.762] in SOFA score alone). CONCLUSIONS: An increasing number of GI symptoms independently predicts 28 day mortality with moderate accuracy. However, it was not possible to develop a GI dysfunction score, improving the performance of the SOFA score either due to data set limitations, definition problems, or possibly indicating that GI dysfunction is often secondary and not the primary cause of other organ failure.

Continuous positive airway pressure (CPAP) is the application in the airways of continuous positive pressure, close to the positive end expiratory pressure. The two common available systems are by a continuous (high/low) flow system and by a mechanical ventilator. Aim of this study was to compare the mechanical performance of the CPAP systems in intubated and not intubated patients. Medical literature databases (MEDLINE and EMBASE) were searched for articles on "clinical trials" and "randomized controlled trials". The key words "continuous positive airway pressure" and "CPAP", were combined with any of these key words: adult, work of breathing, continuous flow, mechanical valve, water valve, balloon reservoir, mechanical ventilator, pressure triggering, flow triggering, lung model, demand valve, equipment. Thirty-two articles (18 human and 14 bench studies) met the inclusion criteria. The continuous flow systems are able to maintain acceptable airway pressure variations during normal breathing. The most recent mechanical ventilators equipped with flow by systems compared to the first one, presented a similar or better work of breathing compared to the continuous flow systems due to the application of a little amount of pressure support. Although the use of a continuous flow is cheaper compared to mechanical ventilators, it does not allow a continuous respiratory monitoring.

According to evidence-based medicine (EBM), physicians must be able to assess and understand scientific evidence generated from biomedical research. Among the many statistical methods involved in the proof of the evidence, an essential area concerns how to select and interpret diagnostic tests to confirm or exclude a diagnosis. Rather surprisingly, these statistical methods are not always correctly reported or satisfactorily explained in some EBM reference books, which leads to misunderstandings and incorrect analyses of published studies in the biomedical literature. In this paper, the authors consider the methodology for performing diagnostic test studies and a correct analysis of the diagnostic test results by explaining it for a clinical audience with a working example.

Part II of this work addresses the use of likelihood ratios for the calculation of a positive predictive value (PPV) and a negative predictive value (NPV) for patient diagnosis. These two values are the most useful indices in the application of a diagnostic test in order to make a diagnosis for a patient. Furthermore, the relevance of sample size is also addressed by providing background theory and pertinent tables. These basic topics for assessing the validity of a diagnostic test and for performing appropriate and valid case vs control studies are explained in a simple way for a clinical audience with a working example.

Introduction In order to improve the efficiency of heat moisture exchangers (HMEs), new hybrid humidifiers (active HMEs) that add water and heat to HMEs have been developed. In this study we evaluated the efficiency, both in vitro and in vivo, of a new active HME (the Performer; StarMed, Mirandola, Italy) as compared with that of existing HMEs (Hygroster and Hygrobac; Mallinckrodt, Mirandola, Italy). Methods We tested the efficiency by measuring the temperature and absolute humidity (AH) in vitro using a test lung ventilated at three levels of minute ventilation (5, 10 and 15 l/min) and at two tidal volumes (0.5 and 1 l), and in vivo in 42 patients with acute lung injury (arterial oxygen tension/fractional inspired oxygen ratio 283 ± 72 mmHg). We also evaluated the efficiency in vivo after 12 hours. Results In vitro, passive Performer and Hygrobac had higher airway temperature and AH (29.2 ± 0.7°C and 29.2 ± 0.5°C, [P < 0.05]; AH: 28.9 ± 1.6 mgH2O/l and 28.1 ± 0.8 mgH2O/l, [P < 0.05]) than did Hygroster (airway temperature: 28.1 ± 0.3°C [P < 0.05]; AH: 27 ± 1.2 mgH2O/l [P < 0.05]). Both devices suffered a loss of efficiency at the highest minute ventilation and tidal volume, and at the lowest minute ventilation. Active Performer had higher airway temperature and AH (31.9 ± 0.3°C and 34.3 ± 0.6 mgH2O/l; [P < 0.05]) than did Hygrobac and Hygroster, and was not influenced by minute ventilation or tidal volume. In vivo, the efficiency of passive Performer was similar to that of Hygrobac but better than Hygroster, whereas Active Performer was better than both. The active Performer exhibited good efficiency when used for up to 12 hours in vivo. Conclusion This study showed that active Performer may provide adequate conditioning of inspired gases, both as a passive and as an active device.

Several guidelines have recommended that antibiotic prophylaxis (AMP) should be given only at premedication, except in selected cases. Conversely, in clinical practice, AMP is often unnecessarily prolonged after the surgical procedure. In this observational study, we evaluated the risk of surgical site infection (SSI) associated with the prolongation of AMP after clean and clean-contaminated surgery.All consecutive patients who underwent a surgical procedure were eligible. AMP was always administered before the surgical incision. Prolongation of AMP for the first 24 hours was allowed only in presence of at least one risk factor for SSI: an ASA score2 or surgical procedure longer than the specific cutoff (as indicated by the NNIS--the National Nosocomial Infections Surveillance System). SSIs were evaluated during the hospital stay and after hospital discharge.Three hundred fifty-eight patients were enrolled; 19 (5.3%) and 17 (6.5%) patients developed respectively intra-hospital and post hospital discharge SSIs. AMP prolongation for 24 hours in patients with at least one risk factor did not reduce the risk for intra-hospital SSI (OR 1.102; 95% CI: 0.336-3.612; P=0.873), while it increased the risk in patients without risk factors (OR: 8.99; 95% CI: 1.46-55.4; P=0.018). AMP longer than 24 hours raised the risk for intra-hospital and post hospital discharge SSI, regardless of the presence of risk factors (OR: 3.39; 95% CI 1.11-10.35; P=0.032 and OR: 5.39; 95% CI: 1.64-17.75; P=0.006, respectively.)Postoperative AMP prolongation should be avoided.

Continuous positive end-expiratory pressure (CPAP) and Pressure Support Ventilation (PSV) are commonly used for the therapy of several forms of respiratory failure. CPAP and PSV can be delivered both during invasive respiratory treatment, by means of an endotracheal tube or tracheostomy, and during non invasive respiratory treatment. Non Invasive Ventilation (NIV) is commonly used for the therapy of several forms of respiratory failure (COPD, Weaning period from Invasive Mechanical Ventilation, Cardiogenic Edema,.) and the helmet could be a good new device to deliver it with a better compliance instead the common facial mask without increasing the nurses' workload.

In the critically ill patient the hemodynamic management is essential. Usually the hemodynamic status is estimated by the measurement of the intravascular pressure or volume and by computing the fluid balance, while the change in body weight estimates the total body water. The fluid balance is computed by subtracting the fluid output to the input. Although the input (fluids, drugs, infusion.) are well known, the output are difficult to correctly compute, because they depend on several factors such as the body-room temperature, amount of humidity and may change with time. Aim of this study was to prospectively evaluate the accuracy of the fluid balance compared to the body weight measured by a dedicated mattress (Hill-Rom).Fifteen critically ill patients were enrolled (mean age of 63.2+/-19.7 years, body mass index of 24.9+/-3.5 kg/m2) and the measurements were computed every 8 hours. The data were analyzed by the Bland-Altman test.Four-hundred and seventy-two measurements for a mean intensive care stay of 12.3.+/-7.3 days were computed. The Bland-Altamn showed a great inaccuracy, because the agreement (the difference between the 2 methods) was poor with a standard deviation of 1 840 L.Although the fluid balance was not accurate, the only body weight without any intravascular measurement is not helpful for a correct clinical hemodynamic management of the patient.

Medical gases conditioning during mechanical invasive ventilation is nowadays a problem. In fact, in spite of conditioning guidelines, absolute humidity (AH) into 25-35 mg/l, clinical evaluation of the optimal level of airway humidification has not yet been established with certainty. Physiologically, during spontaneous respiration the airway hydric balance, inspiratory AH expiratory AH, is negative of 27 mg/l about. Usually the patients on mechanical ventilation have an expiratory AH of 32-33 mg/l. An overhumidification of inspired gases, positive airway hydric balance, gives anatomic-physiological alterations of airways and lung parenchyma. During invasive mechanical ventilation, the practice of active hot humidifiers has a positive or level airway hydric balance. We think that inspired AH must be equal to expired AH to maintain an airway hydric balance at least level. At last, the temperature of inspired gases, with active hot humidifiers, shouldn't exceed 32-34 degrees C.

The results of meta-analyses on the effectiveness of high positive end-expiratory pressure (PEEP) and prone positioning in acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) are not consistent. In addition, the meta-analyses on the activated protein C in patients with sepsis combine trials with discordant results. Therefore, the aim of this paper was to give a critical review of these meta-analyses. All relevant meta-analyses were identified by a computerized search of PubMed using combinations of the following terms: acute lung injury, acute respiratory distress syndrome, positive end-expiratory pressure, mechanical ventilation, prone position, drotrecogin, activated protein C, sepsis, and septic patients. A high level of PEEP and prone ventilation was shown to reduce the mortality in patients with severe acute hypoxemic respiratory failure. Although the evidence for the efficacy of activated protein C is not conclusive, it should be considered in patients that are at a high risk for death without any contraindications related to bleeding risk. Meta-analysis models can be very useful for clinical decisions if they include all of the similar papers on a medical topic and are correct from the methodological point of view; however, these results must be checked by a careful and well-informed reader.

We compared the performance of a heparinized hollow fiber artificial lung (Medtronic, Minimax) featuring standard hollow fibers (Group A) and experimental hollow fibers with a smaller pore size (Group B). Four sheep in each group underwent a veno-venous bypass for 72 hours. Every 6 hours, at 3 different blood flow rates (BFr) (400, 800, 1200 ml/min), at a constant gas flow rate (Gfr = 4 L/min), and at a constant blood inlet PCO2 (45-55 mmHg), we measured the oxygenation performance (O2 transfer = VO2 and blood outlet PO2 = PO2out), CO2 removal (CO2 transfer = VCO2 and PCO2 outlet = PCO2out) and pressure drop across the device (delta P). A total of about 50 measurement sets were obtained for each group at different time points and blood flow rates. Both groups showed a good oxygenation performance (PO2out always higher than 200 mmHg) and no differences were observed between the two groups (at 1200 ml/min BFr, the average VO2 of all time points was 47 +/- 15 ml/min in group A and 44 +/- 11 ml/min in group B, mean +/- SD, NS). During the first 24 hours, the VCO2 was higher in Group B than in Group A at each BFr (at 1200 ml/min BFr, 81 +/- 18 vs 67 +/- 20 ml/min, p0.01), while no differences were observed during the subsequent 48 hours. Throughout the entire experiment, VCO2 increased with increasing BFr in both groups, (in group B, from 43 +/- 14 ml/min at 400 ml/min BFr, to 73 +/- 17 ml/min at 1200 ml/min BFr, average of all time points, p0.01). In both groups the delta P increased with the increasing BFr, but it was lower in Group B than in Group A at BFr 800 and 1200 ml/min (at 1200 ml/min BFr, 51 +/- 15 mmHg vs 65 +/- 17 mmHg, p0.01), and remained stable for the entire experimental period.