Zambrano, Claudia Castillo

OBJECTIVES: The goal of this scoping review was to review some of the challenges hospitals faced in dealing with the shortage of ventilators during the COVID-19 pandemic and the solutions they were able to implement or suggested. By highlighting these problems and solutions, we hope this review can catalyze further discussions about how to better prepare for future pandemics and medical supply shortages. DATA SOURCES: A comprehensive search strategy using identifying key words was applied to several different databases to procure relevant literature. STUDY SELECTION: Four thousand two hundred fifty-nine studies were found in the initial search. Inclusion and exclusion criteria were created and applied to screen studies. Included studies focused on the supply and distribution of ventilators during the COVID-19 pandemic. In the case where reviewers disagreed about whether a study should be included, a third reviewer acted as a tie-breaker. DATA EXTRACTION: Thirty-three studies were included for final data extraction. Two independent reviewers collected various data points from these studies, including the main challenges discussed by the authors, the level of ventilator shortage being addressed, whether ventilator sharing was discussed, and the limitations of the study. DATA SYNTHESIS: A third reviewer compared the collected data and decided on the results. CONCLUSIONS: Some of the common solutions for the ventilator shortage discussed included augmenting overall ventilator supply through increased production, transporting ventilators between hospitals, ventilator sharing, designing new ventilators, and repurposing other resources to help address shortages of supplies.

Objectives There is substantial practice variation in the management strategies for atrial fibrillation (AF) with rapid ventricular rate (RVR) and hemodynamic instability in critically ill patients. This study aimed to evaluate the use and effectiveness of direct current cardioversion (DCCV) for unstable AF RVR in the intensive care unit (ICU). Design Multicenter retrospective cohort study. Setting Non-cardiac/cardiovascular surgery ICUs of the Mayo Clinic Hospitals in Minnesota, Wisconsin, Florida, and Arizona. Patients Adult patients who developed paroxysmal AF RVR with hemodynamic instability (heart rate ≥ 130 beats per minute and a documented SBP ≤ 90 mmHg or the need for vasopressors) during ICU stay. Interventions Emergency DCCV. Measurements and Main Results Primary outcomes were in-hospital mortality, hospital-, ICU-, and organ support-free days. Secondary outcomes were return to sinus rhythm rate before and after discharge. Among 691 patients eligible for inclusion, 47 (6.8%) received emergent DCCV in the ICU. The frequency of DCCV was higher for patients located in surgical ICUs (14.5% vs 6.1%, P = .04). Patients were 1:2 propensity-score matched. The comparative analyses were conducted on 141 patients. Those who underwent DCCV were more likely to restore sinus rhythm (odds ratio [95% confidence interval], 5.2 [1.30 20.8]). However, DCCV was not associated with increased odds of having sinus rhythm at discharge, lower mortality, or higher number of ICU-, or hospital-free days. The number of organ support-free days was significantly lower in the DCCV group (estimate ± standard error, −5.0 ± 2.0, P = .012). Conclusions Emergency DCCV is rarely used to treat unstable AF in non-cardiac ICUs. Despite increased likelihood of immediate sinus rhythm restoration, DCCV was not associated with improvement in patient-centered outcomes. Prospective studies are warranted to evaluate harms and benefits of DCCV in non-cardiac critically ill patients with unstable AF where the driver of hemodynamic instability is often an underlying condition rather than arrhythmia per se.

ABSTRACT Background: Although central venous oxygen saturation (ScvO2) has been used as an endpoint for the treatment of circulatory shock, its role in guiding the evaluation and treatment of patients with severe hypoxemia remains to be assessed. The aim of this study was to assess the incidence of low ScvO2 in a cohort of hypoxemic patients and the association of this finding with differences in clinical management and patient outcomes. Methods: Retrospective review of data from adult intensive care unit patients with hypoxemia who required invasive mechanical ventilation for over 24 h and had at least one ScvO2 measured within 6 h of a PaO2/FiO2 ratio <200. Results: Of 442 mechanically ventilated patients with severe hypoxemia, 249 (56%) had an ScvO2 <70%. When compared with patients with ScvO2 ≥70%, those with low ScvO2 had worse systemic oxygenation and hemodynamic parameters and were more likely to receive red blood cell transfusions (31.7% vs. 18.1%, P = 0.001), epinephrine (27.3% vs. 16.6%, P = 0.007), and inodilators. Outcomes such as median intensive care unit length of stay (7.5 vs. 8.3 days, P = 0.337) and hospital mortality (39.8% vs. 35.7%, P = 0.389) were not different between groups. When stratified by the central venous-to-arterial CO2 difference (∆PCO2), patients with a low ScvO2 and normal ∆PCO2 had lower median PaO2 and hemoglobin levels and received more red blood cell transfusions, whereas those with an increased ∆PCO2 had a lower pulse pressure and cardiac index and were more likely to receive epinephrine and milrinone. Conclusion: Low ScvO2 is frequently observed in mechanically ventilated patients with severe hypoxemia, and these patients receive different interventions. Clinicians often use therapies targeting systemic oxygen delivery to correct low ScvO2. Prospective research is needed to identify patients with severe hypoxemia that might benefit from interventions targeting systemic oxygen delivery.