Nitric Oxide in Cardiac Surgery: A Meta-Analysis of Randomized Controlled Trials.

OBJECTIVES: To investigate the efficacy and safety of perioperative administration of nitric oxide in cardiac surgery. DESIGN: Meta-analysis of randomized controlled trials (RCTs). PARTICIPANTS: Cardiac surgery patients. INTERVENTIONS: A search of Cochrane Central Register of Controlled Trials (CENTRAL), Embase, and MEDLINE for RCTs that compared nitric oxide with placebo or other comparators. MEASUREMENTS AND MAIN RESULTS: The primary outcome was intensive care unit (ICU) stay, and secondary outcomes were mortality, duration of mechanical ventilation, and reduction of mean pulmonary artery pressure. The study included 18 RCTs comprising 958 patients. The authors calculated the pooled odds ratio (OR) and the mean difference (MD) with random-effects model. Quantitative synthesis of data demonstrated a clinically negligible reduction in the length of ICU stay (MD -0.38 days, confidence interval CI [-0.65 to -0.11]; p = 0.005) and mechanical ventilation duration (MD -4.81 hours, CI [-7.79 to -1.83]; p = 0.002) compared with all control interventions with no benefit on mortality. CONCLUSIONS: Perioperative delivery of inhaled nitric oxide resulted to be of no or minimal benefit in patients with pulmonary hypertension undergoing cardiac surgery. Large, randomized trials are needed to further assess its effect on major clinical outcomes and its cost-effectiveness.

Feasibility, safety and efficacy of COVID-19 severe acute respiratory distress syndrome management without invasive mechanical ventilation.

BACKGROUND: COVID-19 acute respiratory distress syndrome (ARDS) is often managed with mechanical ventilation (MV), requiring sedation and paralysis, with associated risk of complications. There is limited evidence on the use of high flow nasal cannula (HFNC). We hypothesized that management of COVID-19 ARDS without MV is feasible. METHODS: Included were all adult patients diagnosed with COVID-19 ARDS, with PaO2/FiO2 ratio <100 at admission, and whose management was initially performed without MV. We evaluated need for intubation during ICU stay, mortality and hospital/ICU length of stay (LOS). RESULTS: Out of 118 patients, 41 were managed only with HFNC from hospital admission (and at least during first 24 hours in ICU) and had a PaO2/FiO2 ratio <100 (72.9±13.0). Twenty-nine out of 41 patients never required MV: 24 of them survived and were discharged home. Their median ICU LOS was 11 (7-17) days, and their hospital LOS was 29 (18-45) days. We identified PaO2/FiO2 ratio at ICU admission as the only significant predictor for need for MV during ICU stay. We also identified age, length of non-invasive respiratory support before ICU admission, mean value of PaO2/FiO2 ratio during first half and whole ICU stay as predictors of mortality. CONCLUSIONS: It is safe to monitor in ICU and use HFNC in patients affected by COVID-19 ARDS who initially present data suggesting an early need for intubation. The 41 patients admitted with a PaO2/FiO2 ratio <100 and initially treated only with HFNC show a 22% mortality that is in the lower range of what is reported in recent literature.