Diaphragm Dysfunction Predicts Weaning Outcome after Bilateral Lung Transplant.

BACKGROUND: Diaphragm dysfunction and its effects on outcomes of ventilator weaning have been evaluated in mixed critical care populations using diaphragm thickening fraction (the ratio of the difference between ultrasound diaphragm thickness at end-inspiration and end-expiration to diaphragm thickness at end-expiration) or neuroventilatory efficiency (the ratio of tidal volume and peak electrical activity of the diaphragm). Such data are not available in bilateral-lung transplant recipients. The authors hypothesized that (1) diaphragm dysfunction, as defined by a diaphragm thickening fraction less than 29%, is more likely to occur in difficult weaning; (2) diaphragm thickening fraction and neuroventilatory efficiency predict weaning outcome; and (3) duration of mechanical ventilation before the first spontaneous breathing trial is associated with diaphragm dysfunction. METHODS: Adult bilateral-lung transplant patients admitted to the intensive care unit were screened at the time of the first spontaneous breathing trial (pressure-support of 5 cm H2O and 0 positive end-expiratory pressure). At the fifth minute, diaphragm thickening fraction and neuroventilatory efficiency were measured during three respiratory cycles. Weaning was classified as simple, difficult, or prolonged (successful extubation at the first spontaneous breathing trial, within three or after three spontaneous breathing trials, respectively). RESULTS: Forty-four subjects were enrolled. Diaphragm dysfunction occurred in 14 subjects (32%), all of whom had difficult weaning (78% of the subgroup of 18 patients experiencing difficult weaning). Both diaphragm thickening fraction (24 [20 to 29] vs. 39 [35 to 45]%) and neuroventilatory efficiency (34 [26 to 45] vs. 55 [43 to 62] ml/µV) were lower in difficult weaning (both P < 0.001). The areas under the receiver operator curve predicting difficult weaning were 0.88 (95% CI, 0.73 to 0.99) for diaphragm thickening fraction and 0.85 (95% CI, 0.71 to 0.95) for neuroventilatory efficiency. The duration of ventilation demonstrated a linear inverse correlation with both diaphragm thickening fraction and neuroventilatory efficiency. CONCLUSIONS: Diaphragm dysfunction is common after bilateral-lung transplantation and associated with difficult weaning. In such patients, average values for diaphragm thickening fraction and neuroventilatory efficiency were reduced compared to patients with simple weaning. Both parameters showed similar accuracy for predicting success of ventilator weaning, demonstrating an inverse relationship with duration of ventilation.

Gram-negative bacterial colonizations before bilateral lung transplant. The impact of 'targeted' versus 'standard' surgical prophylaxis.

BACKGROUND: Infections are one of the most common causes of death after lung transplant (LT). However, the benefit of 'targeted' prophylaxis in LT recipients pre-colonized by Gram-negative (GN) bacteria is still unclear. METHODS: All consecutive bilateral LT recipients admitted to the Intensive Care Unit of the University Hospital of Padua (February 2016-2023) were retrospectively screened. Only patients with pre-existing GN bacterial isolations were enrolled and analyzed according to the antimicrobial surgical prophylaxis ('standard' vs. 'targeted' on the preoperative bacterial isolation). RESULTS: One hundred eighty-one LT recipients were screened, 46 enrolled. Twenty-two (48%) recipients were exposed to 'targeted' prophylaxis, while 24 (52%) to 'standard' prophylaxis. Overall prevalence of postoperative multi-drug resistant (MDR) GN bacteria isolation was 65%, with no differences between the two surgical prophylaxis (p = 0.364). Eleven (79%) patients treated with 'standard' prophylaxis and twelve (75%) with 'targeted' therapy reconfirmed the preoperative GN pathogen (p = 0.999). The prevalence of postoperative infections due to MDR GN bacteria was 50%. Of these recipients, 4 belonged to the 'standard' and 11 to the 'targeted' prophylaxis (p = 0.027). CONCLUSIONS: The administration of a 'targeted' prophylaxis in LT pre-colonized recipients seemed not to prevent the occurrence of postoperative MDR GN infections.

Effects of non-invasive respiratory support in post-operative patients: a systematic review and network meta-analysis.

BACKGROUND: Re-intubation secondary to post-extubation respiratory failure in post-operative patients is associated with increased patient morbidity and mortality. Non-invasive respiratory support (NRS) alternative to conventional oxygen therapy (COT), i.e., high-flow nasal oxygen, continuous positive airway pressure, and non-invasive ventilation (NIV), has been proposed to prevent or treat post-extubation respiratory failure. Aim of the present study is assessing the effects of NRS application, compared to COT, on the re-intubation rate (primary outcome), and time to re-intubation, incidence of nosocomial pneumonia, patient discomfort, intensive care unit (ICU) and hospital length of stay, and mortality (secondary outcomes) in adult patients extubated after surgery. METHODS: A systematic review and network meta-analysis of randomized and non-randomized controlled trials. A search from Medline, Embase, Scopus, Cochrane Central Register of Controlled Trials, and Web of Science from inception until February 2, 2024 was performed. RESULTS: Thirty-three studies (11,292 patients) were included. Among all NRS modalities, only NIV reduced the re-intubation rate, compared to COT (odds ratio 0.49, 95% confidence interval 0.28; 0.87, p = 0.015, I2 = 60.5%, low certainty of evidence). In particular, this effect was observed in patients receiving NIV for treatment, while not for prevention, of post-extubation respiratory failure, and in patients at high, while not low, risk of post-extubation respiratory failure. NIV reduced the rate of nosocomial pneumonia, ICU length of stay, and ICU, hospital, and long-term mortality, while not worsening patient discomfort. CONCLUSIONS: In post-operative patients receiving NRS after extubation, NIV reduced the rate of re-intubation, compared to COT, when used for treatment of post-extubation respiratory failure and in patients at high risk of post-extubation respiratory failure.

Asymmetrical high-flow nasal cannula performs similarly to standard interface in patients with acute hypoxemic post-extubation respiratory failure: a pilot study.

BACKGROUND: Standard high-flow nasal cannula (HFNC) is a respiratory support device widely used to manage post-extubation hypoxemic acute respiratory failure (hARF) due to greater comfort, oxygenation, alveolar recruitment, humidification, and reduction of dead space, as compared to conventional oxygen therapy. On the contrary, the effects of the new asymmetrical HFNC interface (Optiflow® Duet system (Fisher & Paykel, Healthcare, Auckland, New Zealand) is still under discussion. Our aim is investigating whether the use of asymmetrical HFNC interface presents any relevant difference, compared with the standard configuration, on lung aeration (as assessed by end-expiratory lung impedance (EELI) measured by electrical impedance tomography (EIT)), diaphragm ultrasound thickening fraction (TFdi) and excursion (DE), ventilatory efficiency (estimated by corrected minute ventilation (MV)), gas exchange, dyspnea, and comfort. METHODS: Pilot physiological crossover randomized controlled study enrolling 20 adults admitted to the Intensive Care unit, invasively ventilated for at least 24 h, and developing post-extubation hARF, i.e., PaO2/set FiO2 < 300 mmHg during Venturi mask (VM) within 120 min after extubation. Each HFNC configuration was applied in a randomized 60 min sequence at a flow rate of 60 L/min. RESULTS: Global EELI, TFdi, DE, ventilatory efficiency, gas exchange and dyspnea were not significantly different, while comfort was greater during asymmetrical HFNC support, as compared to standard interface (10 [7-10] and 8 [7-9], p-value 0.044). CONCLUSIONS: In post-extubation hARF, the use of the asymmetrical HFNC, as compared to standard HFNC interface, slightly improved patient comfort without affecting lung aeration, diaphragm activity, ventilatory efficiency, dyspnea and gas exchange. CLINICAL TRIAL NUMBER: ClinicalTrial.gov. REGISTRATION NUMBER: NCT05838326 (01/05/2023). NEW & NOTEWORTHY: The asymmetrical high-flow nasal cannula oxygen therapy (Optiflow® Duet system (Fisher & Paykel, Healthcare, Auckland, New Zealand) provides greater comfort as compared to standard interface; while their performance in term of lung aeration, diaphragm activity, ventilatory efficiency, dyspnea, and gas exchange is similar.

General anesthesia or conscious sedation for thrombectomy in stroke patients: an updated systematic review and meta-analysis.

PURPOSE: Endovascular treatment for stroke patients usually requires anesthesia care, with no current consensus on the best anesthetic management strategy. Several randomized controlled trials and meta-analyses have attempted to address this. In 2022, additional evidence from three new trials was published: the GASS trial, the CANVAS II trial, and preliminary results from the AMETIS trial, prompting the execution of this updated systematic review and meta-analysis. The primary objective of this study was to evaluate the effects of general anesthesia and conscious sedation on functional outcomes measured with the modified Rankin scale (mRS) at three months. METHODS: We performed a systematic review and meta-analysis of randomized controlled trials investigating conscious sedation and general anesthesia in endovascular treatment. The following databases were examined: PubMed, Scopus, Embase, and the Cochrane Database of Randomized Controlled Trials and Systematic Reviews. The Risk of Bias 2 tool was used to assess bias. In addition, trial sequence analysis was performed on the primary outcome to estimate if the cumulative effect is significant enough to be unaffected by further studies. RESULTS: Nine randomized controlled trials were identified, including 1,342 patients undergoing endovascular treatment for stroke. No significant differences were detected between general anesthesia and conscious sedation with regards to mRS, functional independence (mRS, 0-2), procedure duration, onset to reperfusion, mortality, hospital length of stay, and intensive care unit length of stay. Patients treated under general anesthesia may have more frequent successful reperfusion, though the time from groin to reperfusion was slightly longer. Trial sequential analysis showed that additional trials are unlikely to show marked differences in mean mRS at three months. CONCLUSIONS: In this updated systematic review and meta-analysis, the choice of anesthetic strategy for endovascular treatment of stroke patients did not significantly impact functional outcome as measured with the mRS at three months. Patients managed with general anesthesia may have more frequent successful reperfusion. TRIAL REGISTRATION: PROSPERO (CRD42022319368); registered 19 April 2022.

RéSUMé: OBJECTIF: Le traitement endovasculaire pour les patient·es victimes d'un accident vasculaire cérébral (AVC) nécessite généralement des soins d'anesthésie, mais il n'existe actuellement aucun consensus sur la meilleure stratégie de prise en charge anesthésique. Plusieurs études randomisées contrôlées et méta-analyses ont tenté d'aborder cette question. En 2022, des données probantes supplémentaires provenant de trois nouvelles études ont été publiées : l'étude GASS, l'étude CANVAS II et les résultats préliminaires de l'étude AMETIS, ce qui a motivé la réalisation de cette revue systématique et méta-analyse mises à jour. L'objectif principal de cette étude était d'évaluer les effets de l'anesthésie générale et de la sédation consciente sur les devenirs fonctionnels mesurés avec l'échelle de Rankin modifiée (mRS) à trois mois. MéTHODE: Nous avons réalisé une revue systématique avec méta-analyse d'études randomisées contrôlées portant sur la sédation consciente et l'anesthésie générale dans le traitement endovasculaire. Les bases de données suivantes ont été examinées : PubMed, Scopus, Embase et la base de données Cochrane des études randomisées contrôlées et des revues systématiques. L'outil Risque de biais 2 a été utilisé pour évaluer le biais. De plus, une analyse séquentielle des études a été effectuée sur le critère d'évaluation principal afin d'estimer si l'effet cumulatif était suffisamment significatif pour ne pas être affecté par d'autres études. RéSULTATS: Neuf études randomisées contrôlées ont été identifiées, incluant 1342 patient·es bénéficiant d'un traitement endovasculaire pour un AVC. Aucune différence significative n'a été détectée entre l'anesthésie générale et la sédation consciente en ce qui concerne la mRS, l'indépendance fonctionnelle (mRS, 0-2), la durée de l'intervention, le moment d'apparition de la reperfusion, la mortalité, la durée de séjour à l'hôpital et la durée de séjour en unité de soins intensifs. Les patient·es traité·es sous anesthésie générale pourraient avoir une reperfusion réussie plus fréquente, bien que le temps entre l'aine et la reperfusion était légèrement plus long. L'analyse séquentielle des études a montré qu'il est peu probable que d'autres études montrent des différences marquées dans la mRS moyenne à trois mois. CONCLUSION: Dans cette revue systématique et méta-analyse mises à jour, le choix de la stratégie anesthésique pour le traitement endovasculaire des personnes victimes d'un AVC n'a pas eu d'impact significatif sur les devenirs fonctionnels mesurés avec la mRS à trois mois. La réussite de la reperfusion pourrait être plus fréquente chez les patient·es pris·es en charge par anesthésie générale. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42022319368); enregistrée le 19 avril 2022.

Early Physiologic Effects of Prone Positioning in COVID-19 Acute Respiratory Distress Syndrome.

BACKGROUND: The mechanisms underlying oxygenation improvement after prone positioning in COVID-19 acute respiratory distress syndrome have not been fully elucidated yet. The authors hypothesized that the oxygenation increase with prone positioning is secondary to the improvement of ventilation-perfusion matching. METHODS: In a series of consecutive intubated COVID-19 acute respiratory distress syndrome patients receiving volume-controlled ventilation, the authors prospectively assessed the percent variation of ventilation-perfusion matching by electrical impedance tomography before and 90 min after the first cycle of prone positioning (primary endpoint). The authors also assessed changes in the distribution and homogeneity of lung ventilation and perfusion, lung overdistention and collapse, respiratory system compliance, driving pressure, optimal positive end-expiratory pressure, as assessed by electrical impedance tomography, and the ratio of partial pressure to fraction of inspired oxygen (Pao2/Fio2; secondary endpoints). Data are reported as medians [25th to 75th] or percentages. RESULTS: The authors enrolled 30 consecutive patients, all analyzed without missing data. Compared to the supine position, prone positioning overall improved ventilation-perfusion matching from 58% [43 to 69%] to 68% [56 to 75%] (P = 0.042), with a median difference of 8.0% (95% CI, 0.1 to 16.0%). Dorsal ventilation increased from 39% [31 to 43%] to 52% [44 to 62%] (P < 0.001), while dorsal perfusion did not significantly vary. Prone positioning also reduced lung overdistension from 9% [4 to 11%] to 4% [2 to 6%] (P = 0.025), while it did not significantly affect ventilation and perfusion homogeneity, lung collapse, static respiratory system compliance, driving pressure, and optimal positive end-expiratory pressure. Pao2/Fio2 overall improved from 141 [104 to 182] mmHg to 235 [164 to 267] mmHg (P = 0.019). However, 9 (30%) patients were nonresponders, experiencing an increase in Pao2/Fio2 less than 20% with respect to baseline. CONCLUSIONS: In COVID-19 acute respiratory distress syndrome patients, prone positioning overall produced an early increase in ventilation-perfusion matching and dorsal ventilation. These effects were, however, heterogeneous among patients.

Single-injection regional analgesia techniques for mastectomy surgery: A network meta-analysis.

BACKGROUND: Patients undergoing mastectomy surgery experience severe postoperative pain. Several regional techniques have been developed to reduce pain intensity but it is unclear, which of these techniques is most effective. OBJECTIVES: To synthesise direct and indirect comparisons for the relative efficacy of different regional and local analgesia techniques in the setting of unilateral mastectomy. Postoperative opioid consumption at 24 h, postoperative pain at extubation, 1, 12 and 24 h, postoperative nausea and vomiting were collected. DESIGN: Systematic review with network meta-analysis (PROSPERO:CRD42021250651). DATA SOURCE: PubMed, Scopus, the Cochrane Central Register of Controlled Trials (from inception until 7 July 2021). ELIGIBILITY CRITERIA: All randomised controlled trials investigating single-injection regional and local analgesia techniques in adult patients undergoing unilateral mastectomy were included in our study without any language or publication date restriction. RESULTS: Sixty-two included studies randomising 4074 patients and investigating nine techniques entered the analysis. All techniques were associated with less opioid consumption compared with controls The greatest mean difference [95% confidence interval (CI)] was associated with deep serratus anterior plane block: mean difference -16.1 mg (95% CI, -20.7 to -11.6). The greatest reduction in pain score was associated with the interpectoral-pecto-serratus plane block (mean difference -1.3, 95% CI, -1.6 to - 1) at 12 h postoperatively, and with superficial serratus anterior plane block (mean difference -1.4, 95% CI, -2.4 to -0.5) at 24 h. Interpectoral-pectoserratus plane block resulted in the greatest statistically significant reduction in postoperative nausea/vomiting when compared with placebo/no intervention with an OR of 0.23 (95% CI, 0.13 to 0.40). CONCLUSION: All techniques were associated with superior analgesia and less opioid consumption compared with controls. No single technique was identified as superior to others. In comparison, local anaesthetic infiltration does not offer advantages over multimodal analgesia alone. TRIAL REGISTRATION: PROSPERO (CRD4202125065).

Higher versus lower positive end-expiratory pressure in patients without acute respiratory distress syndrome: a meta-analysis of randomized controlled trials.

BACKGROUND: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the association of higher positive end-expiratory pressure (PEEP), as opposed to lower PEEP, with hospital mortality in adult intensive care unit (ICU) patients undergoing invasive mechanical ventilation for reasons other than acute respiratory distress syndrome (ARDS). METHODS: We performed an electronic search of MEDLINE, EMBASE, Scopus, Cochrane Central Register of Controlled Trials, CINAHL, and Web of Science from inception until June 16, 2021 with no language restrictions. In addition, a research-in-progress database and grey literature were searched. RESULTS: We identified 22 RCTs (2225 patients) comparing higher PEEP (1007 patients) with lower PEEP (991 patients). No statistically significant association between higher PEEP and hospital mortality was observed (risk ratio 1.02, 95% confidence interval 0.89-1.16; I2 = 0%, p = 0.62; low certainty of evidence). Among secondary outcomes, higher PEEP was associated with better oxygenation, higher respiratory system compliance, and lower risk of hypoxemia and ARDS occurrence. Furthermore, barotrauma, hypotension, duration of ventilation, lengths of stay, and ICU mortality were similar between the two groups. CONCLUSIONS: In our meta-analysis of RCTs, higher PEEP, compared with lower PEEP, was not associated with mortality in patients without ARDS receiving invasive mechanical ventilation. Further large high-quality RCTs are required to confirm these findings.

Static compliance and driving pressure are associated with ICU mortality in intubated COVID-19 ARDS.

BACKGROUND: Pathophysiological features of coronavirus disease 2019-associated acute respiratory distress syndrome (COVID-19 ARDS) were indicated to be somewhat different from those described in nonCOVID-19 ARDS, because of relatively preserved compliance of the respiratory system despite marked hypoxemia. We aim ascertaining whether respiratory system static compliance (Crs), driving pressure (DP), and tidal volume normalized for ideal body weight (VT/kg IBW) at the 1st day of controlled mechanical ventilation are associated with intensive care unit (ICU) mortality in COVID-19 ARDS. METHODS: Observational multicenter cohort study. All consecutive COVID-19 adult patients admitted to 25 ICUs belonging to the COVID-19 VENETO ICU network (February 28th-April 28th, 2020), who received controlled mechanical ventilation, were screened. Only patients fulfilling ARDS criteria and with complete records of Crs, DP and VT/kg IBW within the 1st day of controlled mechanical ventilation were included. Crs, DP and VT/kg IBW were collected in sedated, paralyzed and supine patients. RESULTS: A total of 704 COVID-19 patients were screened and 241 enrolled. Seventy-one patients (29%) died in ICU. The logistic regression analysis showed that: (1) Crs was not linearly associated with ICU mortality (p value for nonlinearity = 0.01), with a greater risk of death for values < 48 ml/cmH2O; (2) the association between DP and ICU mortality was linear (p value for nonlinearity = 0.68), and increasing DP from 10 to 14 cmH2O caused significant higher odds of in-ICU death (OR 1.45, 95% CI 1.06-1.99); (3) VT/kg IBW was not associated with a significant increase of the risk of death (OR 0.92, 95% CI 0.55-1.52). Multivariable analysis confirmed these findings. CONCLUSIONS: Crs < 48 ml/cmH2O was associated with ICU mortality, while DP was linearly associated with mortality. DP should be kept as low as possible, even in the case of relatively preserved Crs, irrespective of VT/kg IBW, to reduce the risk of death.

Effect of Driving Pressure Change During Extracorporeal Membrane Oxygenation in Adults With Acute Respiratory Distress Syndrome: A Randomized Crossover Physiologic Study.

OBJECTIVES: Venovenous extracorporeal membrane oxygenation is an effective intervention to improve gas exchange in patients with severe acute respiratory distress syndrome. However, the mortality of patients with severe acute respiratory distress syndrome supported with venovenous extracorporeal membrane oxygenation remains high, and this may be due in part to a lack of standardized mechanical ventilation strategies aimed at further minimizing ventilator-induced lung injury. We tested whether a continuous positive airway pressure ventilation strategy mitigates ventilator-induced lung injury in patients with severe acute respiratory distress syndrome on venovenous extracorporeal membrane oxygenation, compared with current ventilation practice that employs tidal ventilation with limited driving pressure. We used plasma biomarkers as a surrogate outcome for ventilator-induced lung injury. DESIGN: Randomized crossover physiologic study. SETTING: Single-center ICU. PATIENTS: Ten patients with severe acute respiratory distress syndrome supported on venovenous extracorporeal membrane oxygenation. INTERVENTIONS: The study included four phases. After receiving pressure-controlled ventilation with driving pressure of 10 cm H2O for 1 hour (phase 1), patients were randomly assigned to receive first either pressure-controlled ventilation 20 cm H2O for 2 hours (phase 2) or continuous positive airway pressure for 2 hours (phase 3), and then crossover to the other phase for 2 hours; during phase 4 ventilation settings returned to baseline (pressure-controlled ventilation 10 cm H2O) for 4 hours. MEASUREMENTS AND MAIN RESULTS: There was a linear relationship between the change in driving pressure and the plasma concentration of interleukin-6, soluble receptor for advanced glycation end products, interleukin-1ra, tumor necrosis factor alpha, surfactant protein D, and interleukin-10. CONCLUSIONS: Ventilator-induced lung injury may occur in acute respiratory distress syndrome patients on venovenous extracorporeal membrane oxygenation despite the delivery of volume- and pressure-limited mechanical ventilation. Reducing driving pressure to zero may provide more protective mechanical ventilation in acute respiratory distress syndrome patients supported with venovenous extracorporeal membrane oxygenation. However, the risks versus benefits of such an approach need to be confirmed in studies that are designed to test patient centered outcomes.

Effect of Neurally Adjusted Ventilatory Assist on Patient-Ventilator Interaction in Mechanically Ventilated Adults: A Systematic Review and Meta-Analysis.

OBJECTIVES: Patient-ventilator asynchrony is common among critically ill patients undergoing mechanical ventilation and has been associated with adverse outcomes. Neurally adjusted ventilatory assist is a ventilatory mode that may lead to improved patient-ventilator synchrony. We conducted a systematic review to determine the impact of neurally adjusted ventilatory assist on patient-ventilator asynchrony, other physiologic variables, and clinical outcomes in adult patients undergoing invasive mechanical ventilation in comparison with conventional pneumatically triggered ventilatory modes. DATA SOURCES: We searched Medline, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central, CINAHL, Scopus, Web of Science, conference abstracts, and ClinicalTrials.gov until July 2018. STUDY SELECTION: Two authors independently screened titles and abstracts for randomized and nonrandomized controlled trials (including crossover design) comparing the occurrence of patient-ventilator asynchrony between neurally adjusted ventilatory assist and pressure support ventilation during mechanical ventilation in critically ill adults. The asynchrony index and severe asynchrony (i.e., asynchrony index > 10%) were the primary outcomes. DATA EXTRACTION: Two authors independently extracted study characteristics and outcomes and assessed risk of bias of included studies. DATA SYNTHESIS: Of 11,139 unique citations, 26 studies (522 patients) met the inclusion criteria. Sixteen trials were included in the meta-analysis using random effects models through the generic inverse variance method. In several different clinical scenarios, the use of neurally adjusted ventilatory assist was associated with significantly reduced asynchrony index (mean difference, -8.12; 95% CI, -11.61 to -4.63; very low quality of evidence) and severe asynchrony (odds ratio, 0.42; 95% CI, 0.23-0.76; moderate quality of evidence) as compared with pressure support ventilation. Furthermore, other measurements of asynchrony were consistently improved during neurally adjusted ventilatory assist. CONCLUSIONS: Neurally adjusted ventilatory assist improves patient-ventilator synchrony; however, its effects on clinical outcomes remain uncertain. Randomized controlled trials are needed to determine whether the physiologic efficiency of neurally adjusted ventilatory assist affects patient-important outcomes in critically ill adults.

Association of Driving Pressure With Mortality Among Ventilated Patients With Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis.

OBJECTIVES: A recent post hoc analysis suggested that driving pressure may be more important than traditional ventilatory variables in determining outcome in mechanically ventilated patients with acute respiratory distress syndrome. We conducted a systematic review and meta-analysis to summarize the risk of mortality for higher versus lower driving pressure. DATA SOURCES: MEDLINE, EMBASE, PubMed, CINAHL, and Cochrane CENTRAL from inception to February 10, 2017. STUDY SELECTION: Studies including mechanically ventilated adult patients with acute respiratory distress syndrome, reporting driving pressure and mortality. DATA EXTRACTION: Seven studies including five secondary analysis of previous randomized controlled trials and two observational studies (6,062 patients) were eligible for study. All studies were judged as having a low risk of bias. Median (interquartile range) driving pressure between higher and lower driving pressure groups was 15 cm H2O (14-16 cm H2O). Median (interquartile range) mortality of all included studies was 34% (32-38%). DATA SYNTHESIS: In the meta-analyses of four studies (3,252 patients), higher driving pressure was associated with a significantly higher mortality (pooled risk ratio, 1.44; 95% [CI], 1.11-1.88; I = 85%). A sensitivity analysis restricted to the three studies with similar driving pressure cutoffs (13-15 cm H2O) demonstrated similar results (pooled risk ratio, 1.28; 95% CI, 1.14-1.43; I = 0%). CONCLUSIONS: Our study confirmed an association between higher driving pressure and higher mortality in mechanically ventilated patients with acute respiratory distress syndrome. These findings suggest a possible range of driving pressure to be evaluated in clinical trials. Future research is needed to ascertain the benefit of ventilatory strategies targeting driving pressure in patients with acute respiratory distress syndrome.

Blood Products Transfusion and Mid-Term Outcomes of Lung Transplanted Patients Under Extracorporeal Membrane Oxygenation Support.

INTRODUCTION: Extracorporeal membrane oxygenation (ECMO) is considered a reliable technique in lung transplantation requiring cardiorespiratory support. However, the impact of this technology on blood product transfusion rate and outcomes compared to off-pump lung transplantation has been rarely investigated. METHODS: Between January 2012 and June 2015, 52 elective adult lung transplants were performed at our institution. Of these, 15 recipients required intraoperative venoarterial extracorporeal support and 37 did not. We compared blood product consumption and other outcome variables between the 2 groups. RESULTS: We found comparable in-hospital (86.7% vs 97.3%, P = .14) and 6-month (86.7% vs 91.9%, P = .56) survival between patients with and without extracorporeal support, respectively. Survival at 30 days was lower in the ECMO group (86.7% vs 100%, P = .02). Although patients who underwent ECMO received more intraoperative transfusions, postoperative transfusion rate was similar between the 2 groups. The ECMO group experienced longer mechanical ventilation (median 3 vs 2 days, P = .02) and intensive care unit stay (median 7 vs 5 days, P = .02), besides more cardiogenic shock and deep vein thrombosis. However, we observed no difference in other major and minor in-hospital complications and 6-month complications. CONCLUSIONS: In our experience, despite the higher need for intraoperative transfusions, lung transplantation performed with ECMO support is comparable to the off-pump procedure as to short-term survival and outcomes.