Rationale: Baseline characteristics and management have changed over time in patients requiring mechanical ventilation; however, the impact of these changes on patient outcomes is unclear. Objectives: To estimate whether mortality in mechanically ventilated patients has changed over time. Methods: Prospective cohort studies conducted in 1998, 2004, and 2010, including patients receiving mechanical ventilation for more than 12 hours in a 1-month period, from 927 units in 40 countries. To examine effects over time on mortality in intensive care units, we performed generalized estimating equation models. Measurements and Main Results: We included 18,302 patients. The reasons for initiating mechanical ventilation varied significantly among cohorts. Ventilatory management changed over time (P < 0.001), with increased use of noninvasive positive-pressure ventilation (5% in 1998 to 14% in 2010), a decrease in tidal volume (mean 8.8 ml/kg actual body weight [SD = 2.1] in 1998 to 6.9 ml/kg [SD = 1.9] in 2010), and an increase in applied positive end-expiratory pressure (mean 4.2 cm H2O [SD = 3.8] in 1998 to 7.0 cm of H2O [SD = 3.0] in 2010). Crude mortality in the intensive care unit decreased in 2010 compared with 1998 (28 versus 31%; odds ratio, 0.87; 95% confidence interval, 0.80–0.94), despite a similar complication rate. Hospital mortality decreased similarly. After adjusting for baseline and management variables, this difference remained significant (odds ratio, 0.78; 95% confidence interval, 0.67–0.92). Conclusions: Patient characteristics and ventilation practices have changed over time, and outcomes of mechanically ventilated patients have improved. Clinical trials registered with www.clinicaltrials.gov (NCT01093482).

This report summarizes current physiological and technical knowledge on esophageal pressure (Pes) measurements in patients receiving mechanical ventilation. The respiratory changes in Pes are representative of changes in pleural pressure. The difference between airway pressure (Paw) and Pes is a valid estimate of transpulmonary pressure. Pes helps determine what fraction of Paw is applied to overcome lung and chest wall elastance. Pes is usually measured via a catheter with an air-filled thin-walled latex balloon inserted nasally or orally. To validate Pes measurement, a dynamic occlusion test measures the ratio of change in Pes to change in Paw during inspiratory efforts against a closed airway. A ratio close to unity indicates that the system provides a valid measurement. Provided transpulmonary pressure is the lung-distending pressure, and that chest wall elastance may vary among individuals, a physiologically based ventilator strategy should take the transpulmonary pressure into account. For monitoring purposes, clinicians rely mostly on Paw and flow waveforms. However, these measurements may mask profound patient–ventilator asynchrony and do not allow respiratory muscle effort assessment. Pes also permits the measurement of transmural vascular pressures during both passive and active breathing. Pes measurements have enhanced our understanding of the pathophysiology of acute lung injury, patient–ventilator interaction, and weaning failure. The use of Pes for positive end-expiratory pressure titration may help improve oxygenation and compliance. Pes measurements make it feasible to individualize the level of muscle effort during mechanical ventilation and weaning. The time is now right to apply the knowledge obtained with Pes to improve the management of critically ill and ventilator-dependent patients.

Rationale: Oxygen is commonly administered after extubation. Although several devices are available, data about their clinical efficacy are scarce. Objectives: To compare the effects of the Venturi mask and the nasal high-flow (NHF) therapy on PaO2/FiO2SET ratio after extubation. Secondary endpoints were to assess effects on patient discomfort, adverse events, and clinical outcomes. Methods: Randomized, controlled, open-label trial on 105 patients with a PaO2/FiO2 ratio less than or equal to 300 immediately before extubation. The Venturi mask (n = 52) or NHF (n = 53) were applied for 48 hours postextubation. Measurements and Main Results: PaO2/FiO2SET, patient discomfort caused by the interface and by symptoms of airways dryness (on a 10-point numerical rating scale), interface displacements, oxygen desaturations, need for ventilator support, and reintubation were assessed up to 48 hours after extubation. From the 24th hour, PaO2/FiO2SET was higher with the NHF (287 ± 74 vs. 247 ± 81 at 24 h; P = 0.03). Discomfort related both to the interface and to airways dryness was better with NHF (respectively, 2.6 ± 2.2 vs. 5.1 ± 3.3 at 24 h, P = 0.006; 2.2 ± 1.8 vs. 3.7 ± 2.4 at 24 h, P = 0.002). Fewer patients had interface displacements (32% vs. 56%; P = 0.01), oxygen desaturations (40% vs. 75%; P < 0.001), required reintubation (4% vs. 21%; P = 0.01), or any form of ventilator support (7% vs. 35%; P < 0.001) in the NHF group. Conclusions: Compared with the Venturi mask, NHF results in better oxygenation for the same set FiO2 after extubation. Use of NHF is associated with better comfort, fewer desaturations and interface displacements, and a lower reintubation rate. Clinical trial registered with www.clinicaltrials.gov (NCT 01575353).

In randomized studies of heterogeneous patients with hypoxemic acute respiratory failure, noninvasive positive pressure ventilation (NPPV) was associated with a significant reduction in endotracheal intubation. The role of NPPV in patients with acute respiratory distress syndrome (ARDS) is still unclear. The objective was to investigate the application of NPPV as a first-line intervention in patients with early ARDS, describing what happens in everyday clinical practice in centers having expertise with NPPV. Prospective, multiple-center cohort study. Three European intensive care units having expertise with NPPV. Between March 2002 and April 2004, 479 patients with ARDS were admitted to the intensive care units. Three hundred and thirty-two ARDS patients were already intubated, so 147 were eligible for the study. Application of NPPV. NPPV improved gas exchange and avoided intubation in 79 patients (54%). Avoidance of intubation was associated with less ventilator-associated pneumonia (2% vs. 20%; p < .001) and a lower intensive care unit mortality rate (6% vs. 53%; p < .001). Intubation was more likely in patients who were older (p = .02), had a higher Simplified Acute Physiology Score (SAPS) II (p < .001), or needed a higher level of positive end-expiratory pressure (p = .03) and pressure support ventilation (p = .02). Only SAPS II >34 and a Pao2/Fio2 ≤175 after 1 hr of NPPV were independently associated with NPPV failure and need for endotracheal intubation. In expert centers, NPPV applied as first-line intervention in ARDS avoided intubation in 54% of treated patients. A SAPS II >34 and the inability to improve Pao2/Fio2 after 1 hr of NPPV were predictors of failure.

Rationale and Objectives: Duration of weaning from mechanical ventilation may be reduced by the use of a systematic approach. We assessed whether a closed-loop knowledge-based algorithm introduced in a ventilator to act as a computer-driven weaning protocol can improve patient outcomes as compared with usual care. Methods and Measurements: We conducted a multicenter randomized controlled study with concealed allocation to compare usual care for weaning with computer-driven weaning. The computerized protocol included an automatic gradual reduction in pressure support, automatic performance of spontaneous breathing trials (SBT), and generation of an incentive message when an SBT was successfully passed. One hundred forty-four patients were enrolled before weaning initiation. They were randomly allocated to computer-driven weaning or to physician-controlled weaning according to local guidelines. Weaning duration until successful extubation and total duration of ventilation were the primary endpoints. Main Results: Weaning duration was reduced in the computer-driven group from a median of 5 to 3 d (p = 0.01) and total duration of mechanical ventilation from 12 to 7.5 d (p = 0.003). Reintubation rate did not differ (23 vs. 16%, p = 0.40). Computer-driven weaning also decreased median intensive care unit (ICU) stay duration from 15.5 to 12 d (p = 0.02) and caused no adverse events. The amount of sedation did not differ between groups. In the usual care group, compliance to recommended modes and to SBT was estimated, respectively, at 96 and 51%. Conclusions: The specific computer-driven system used in this study can reduce mechanical ventilation duration and ICU length of stay, as compared with a physician-controlled weaning process.

Rationale: Intensive care unit (ICU) patients undergo several diagnostic and therapeutic procedures every day. The prevalence, intensity, and risk factors of pain related to these procedures are not well known. Objectives: To assess self-reported procedural pain intensity versus baseline pain, examine pain intensity differences across procedures, and identify risk factors for procedural pain intensity. Methods: Prospective, cross-sectional, multicenter, multinational study of pain intensity associated with 12 procedures. Data were obtained from 3,851 patients who underwent 4,812 procedures in 192 ICUs in 28 countries. Measurements and Main Results: Pain intensity on a 0–10 numeric rating scale increased significantly from baseline pain during all procedures (P < 0.001). Chest tube removal, wound drain removal, and arterial line insertion were the three most painful procedures, with median pain scores of 5 (3–7), 4.5 (2–7), and 4 (2–6), respectively. By multivariate analysis, risk factors independently associated with greater procedural pain intensity were the specific procedure; opioid administration specifically for the procedure; preprocedural pain intensity; preprocedural pain distress; intensity of the worst pain on the same day, before the procedure; and procedure not performed by a nurse. A significant ICU effect was observed, with no visible effect of country because of its absorption by the ICU effect. Some of the risk factors became nonsignificant when each procedure was examined separately. Conclusions: Knowledge of risk factors for greater procedural pain intensity identified in this study may help clinicians select interventions that are needed to minimize procedural pain. Clinical trial registered with www.clinicaltrials.gov (NCT 01070082).