Comparison of Noninvasive Mechanical Ventilation With High-Flow Nasal Cannula, Face-Mask, and Helmet in Hypoxemic Respiratory Failure in Patients With COVID-19: A Randomized Controlled Trial.

OBJECTIVES: For COVID-19-related respiratory failure, noninvasive respiratory assistance via a high-flow nasal cannula (HFNC), helmet, and face-mask noninvasive ventilation is used. However, which of these options is most effective is yet to be determined. This study aimed to compare the three techniques of noninvasive respiratory support and to determine the superior technique. DESIGN: A randomized control trial with permuted block randomization of nine cases per block for each parallel, open-labeled arm. SETTING AND PATIENTS: Adult patients with COVID-19 with a Pa o2 /F io2 ratio of less than 300, admitted between February 4, 2021, and August 9, 2021, to three tertiary centers in Oman, were studied. INTERVENTIONS: This study included three interventions: HFNC ( n = 47), helmet continuous positive airway pressure (CPAP; n = 52), and face-mask CPAP ( n = 52). MEASUREMENTS AND MAIN RESULTS: The endotracheal intubation rate and mortality at 28 and 90 days were measured as the primary and secondary outcomes, respectively. Of the 159 randomized patients, 151 were analyzed. The median age was 52 years, and 74% were men. The endotracheal intubation rates were 44%, 45%, and 46% ( p = 0.99), and the median intubation times were 7.0, 5.5, and 4.5 days ( p = 0.11) in the HFNC, face-mask CPAP, and helmet CPAP, respectively. In comparison to face-mask CPAP, the relative risk of intubation was 0.97 (95% CI, 0.63-1.49) for HFNC and 1.0 (95% CI 0.66-1.51) for helmet CPAP. The mortality rates were 23%, 32%, and 38% at 28 days ( p = 0.24) and 43%, 38%, and 40% ( p = 0.89) at 90 days for HFNC, face-mask CPAP, and helmet CPAP, respectively. The trial was stopped prematurely because of a decline in cases. CONCLUSIONS: This exploratory trial found no difference in intubation rate and mortality among the three intervention groups for the COVID-19 patients with hypoxemic respiratory failure; however, more evidence is needed to confirm these findings as the trial was aborted prematurely.

Early Prone versus Supine Positioning in Moderate to Severe Coronavirus Disease 2019 Patients with Acute Respiratory Distress Syndrome.

Objectives: This study sought to determine whether early prone positioning of patients with moderate to severe COVID-19-related acute respiratory distress syndrome (ARDS) lowers the mortality rate. Methods: We conducted a retrospective study using data from intensive care units of two tertiary centers in Oman. Adult patients with moderate to severe COVID-19-related ARDS with a PaO2/FiO2 ratio < 150 on FiO2 of 60% or more and a positive end-expiratory pressure of at least 8 cm H2O who were admitted between 1 May 2020 and 31 October 2020 were selected as participants. All patients were intubated and subjected to mechanical ventilation within 48 hours of admission and placed in either prone or supine position. Mortality was measured and compared between the patients from the two groups. Results: A total of 235 patients were included (120 in the prone group and 115 in the supine group). There were no significant differences in mortality (48.3% vs. 47.8%; p =0.938) and discharge rates (50.8% vs. 51.3%; p =0.942) between the prone and supine groups, respectively. Conclusions: Early prone positioning of patients with COVID-19-related ARDS does not result in a significant reduction in mortality.

Contrast Media-Induced Immune Hemolytic Anemia.

Drug-induced immune hemolytic anemia (DIIHA) is a rare type of immune-mediated hemolytic anemia, and mainly it is caused by antibiotics. There have been few case reports of contrast medium-induced immune hemolytic anemia. Here, we report a case of a 70-year-old woman who was admitted with community-acquired pneumonia. She had a CT abdomen and pelvis using iohexol (omnipaque), which resulted in severe hemolytic anemia and contributed to the patient's death. This case illustrates a very rare complication of IV contrast medium that may result in death.

Noninvasive ventilation in patients with acute cardiogenic pulmonary edema.

Acute cardiogenic pulmonary edema (ACPE) is a common cause of respiratory failure that necessitates endotracheal intubation. In some patients intubation and its attendant complications can be avoided with noninvasive ventilation (NIV). Both continuous positive airway pressure (CPAP) and NIV have been evaluated in patients with ACPE. Compared to conventional treatment, both CPAP and NIV improve vital signs and physiologic variables, and reduce intubation rate, in patients with ACPE. Both CPAP and NIV appear to be well tolerated and are not associated with any serious adverse events. Initial concern that NIV may be associated with a greater risk of myocardial infarction than CPAP was laid to rest by later studies. Despite a physiologic rationale that NIV should offer greater benefit than CPAP, NIV has not been found to offer any advantages regarding intubation rate or mortality compared with CPAP. We review the randomized controlled trials and summarize the evidence on NIV and CPAP in patients with ACPE.