Randomized clinical trial comparing helmet continuous positive airway pressure (hCPAP) to facemask continuous positive airway pressure (fCPAP) for the treatment of acute respiratory failure in the emergency department.

STUDY OBJECTIVE: To determine whether non-invasive ventilation (NIV) delivered by helmet continuous positive airway pressure (hCPAP) is non-inferior to facemask continuous positive airway pressure (fCPAP) in patients with acute respiratory failure in the emergency department (ED). METHODS: Non-inferiority randomized, clinical trial involving patients presenting with acute respiratory failure conducted in the ED of a local hospital. Participants were randomly allocated to receive either hCPAP or fCPAP as per the trial protocol. The primary endpoint was respiratory rate reduction. Secondary endpoints included discomfort, improvement in Dyspnea and Likert scales, heart rate reduction, arterial blood oxygenation, partial pressure of carbon dioxide (PaCO2), dryness of mucosa and intubation rate. RESULTS: 224 patients were included and randomized (113 patients to hCPAP, 111 to fCPAP). Both techniques reduced respiratory rate (hCPAP: from 33.56 ± 3.07 to 25.43 ± 3.11 bpm and fCPAP: from 33.46 ± 3.35 to 27.01 ± 3.19 bpm), heart rate (hCPAP: from 114.76 ± 15.5 to 96.17 ± 16.50 bpm and fCPAP: from 115.07 ± 14.13 to 101.19 ± 16.92 bpm), and improved dyspnea measured by both the Visual Analogue Scale (hCPAP: from 16.36 ± 12.13 to 83.72 ± 12.91 and fCPAP: from 16.01 ± 11.76 to 76.62 ± 13.91) and the Likert scale. Both CPAP techniques improved arterial oxygenation (PaO2 from 67.72 ± 8.06 mmHg to 166.38 ± 30.17 mmHg in hCPAP and 68.99 ± 7.68 mmHg to 184.49 ± 36.38 mmHg in fCPAP) and the PaO2:FiO2 (Partial pressure of arterial oxygen: Fraction of inspired oxygen) ratio from 113.6 ± 13.4 to 273.4 ± 49.5 in hCPAP and 115.0 ± 12.9 to 307.7 ± 60.9 in fCPAP. The intubation rate was lower with hCPAP (4.4% for hCPAP versus 18% for fCPAP, absolute difference -13.6%, p = 0.003). Discomfort and dryness of mucosa were also lower with hCPAP. CONCLUSION: In patients presenting to the ED with acute cardiogenic pulmonary edema or decompensated COPD, hCPAP was non-inferior to fCPAP and resulted in greater comfort levels and lower intubation rate.

The association between early arterial oxygenation and mortality in ventilated patients with acute ischaemic stroke.

BACKGROUND: There are conflicting data that suggest that hyperoxia may be associated with either worse or better outcomes in patients suffering a stroke. OBJECTIVES: To investigate the association between PaO(2) in the first 24 hours in the intensive care unit and mortality among ventilated patients with acute ischaemic stroke. DESIGN: Retrospective cohort study. SETTING: Data were extracted from the Australian and New Zealand Intensive Care Society Adult Patient Database. PARTICIPANTS: Adults ventilated for ischaemic stroke in 129 ICUs in Australia and New Zealand, 2000-2009. MAIN OUTCOME MEASURES: The primary outcome was the odds ratio for in hospital mortality associated with "worst" PaO(2) considered as a categorical variable, with data divided into deciles and compared with the mortality of the 10th decile. For patients on an FiO(2) of _50% at any time in the first 24 hours, "worst" PaO(2) was defined as the PaO(2) associated with the highest alveolar-arterial (A-a) gradient. For patients on an FiO(2) of <50%, it was defined as the lowest PaO(2). Secondary outcomes were ICU and hospital length of stay and the proportion of patients in each decile discharged home. RESULTS: Of the 2643 patients eligible for study inclusion, 1507 (57%) died in hospital. The median "worst" PaO(2) was 117mmHg (interquartile range, 87-196mmHg). There was no association between worst PaO(2) and mortality, length of stay or likelihood of discharge home. CONCLUSIONS: We found no association between worst arterial oxygen tension in the first 24 hours in ICU and outcome in ventilated patients with ischaemic stroke.