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.

A feasibility study on bedside upper airway ultrasonography compared to waveform capnography for verifying endotracheal tube location after intubation.

BACKGROUND: In emergency settings, verification of endotracheal tube (ETT) location is important for critically ill patients. Ignorance of oesophageal intubation can be disastrous. Many methods are used for verification of the endotracheal tube location; none are ideal. Quantitative waveform capnography is considered the standard of care for this purpose but is not always available and is expensive. Therefore, this feasibility study is conducted to compare a cheaper alternative, bedside upper airway ultrasonography to waveform capnography, for verification of endotracheal tube location after intubation. METHODS: This was a prospective, single-centre, observational study, conducted at the HRPB, Ipoh. It included patients who were intubated in the emergency department from 28 March 2012 to 17 August 2012. A waiver of consent had been obtained from the Medical Research Ethics Committee. Bedside upper airway ultrasonography was performed after intubation and compared to waveform capnography. Specificity, sensitivity, positive and negative predictive value and likelihood ratio are calculated. RESULTS: A sample of 107 patients were analysed, and 6 (5.6%) had oesophageal intubations. The overall accuracy of bedside upper airway ultrasonography was 98.1% (95% confidence interval (CI) 93.0% to 100.0%). The kappa value (Κ) was 0.85, indicating a very good agreement between the bedside upper airway ultrasonography and waveform capnography. Thus, bedside upper airway ultrasonography is in concordance with waveform capnography. The sensitivity, specificity, positive predictive value and negative predictive value of bedside upper airway ultrasonography were 98.0% (95% CI 93.0% to 99.8%), 100% (95% CI 54.1% to 100.0%), 100% (95% CI 96.3% to 100.0%) and 75.0% (95% CI 34.9% to 96.8%). The likelihood ratio of a positive test is infinite and the likelihood ratio of a negative test is 0.0198 (95% CI 0.005 to 0.0781). The mean confirmation time by ultrasound is 16.4 s. No adverse effects were recorded. CONCLUSIONS: Our study shows that ultrasonography can replace waveform capnography in confirming ETT placement in centres without capnography. This can reduce incidence of unrecognised oesophageal intubation and prevent morbidity and mortality. TRIAL REGISTRATION: National Medical Research Register NMRR11100810230.