Core Warming of Coronavirus Disease 2019 Patients Undergoing Mechanical Ventilation: A Pilot Study.

Fever is a recognized protective factor in patients with sepsis, and growing data suggest beneficial effects on outcomes in sepsis with elevated temperature, with a recent pilot randomized controlled trial (RCT) showing lower mortality by warming afebrile sepsis patients in the intensive care unit (ICU). The objective of this prospective single-site RCT was to determine if core warming improves respiratory physiology of mechanically ventilated patients with coronavirus disease 2019 (COVID-19), allowing earlier weaning from ventilation, and greater overall survival. A total of 19 patients with mean age of 60.5 (±12.5) years, 37% female, mean weight 95.1 (±18.6) kg, and mean body mass index 34.5 (±5.9) kg/m2 with COVID-19 requiring mechanical ventilation were enrolled from September 2020 to February 2022. Patients were randomized 1:1 to standard of care or to receive core warming for 72 hours through an esophageal heat exchanger commonly utilized in critical care and surgical patients. The maximum target temperature was 39.8°C. A total of 10 patients received usual care and 9 patients received esophageal core warming. After 72 hours of warming, the ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2) ratios were 197 (±32) and 134 (±13.4), cycle thresholds were 30.8 (±6.4) and 31.4 (±3.2), ICU mortalities were 40% and 44%, 30-day mortalities were 30% and 22%, and mean 30-day ventilator-free days were 11.9 (±12.6) and 6.8 (±10.2) for standard of care and warmed patients, respectively (p = NS). This pilot study suggests that core warming of patients with COVID-19 undergoing mechanical ventilation is feasible and appears safe. Optimizing time to achieve febrile-range temperature may require a multimodal temperature management strategy to further evaluate effects on outcome. ClinicalTrials.gov Identifier: NCT04494867.

Emergency bedside extracorporeal membrane oxygenation for rescue of acute tracheal obstruction.

A 39-year-old man experienced total obstruction of a distal tracheal plastic stent by a tumor mass, preventing effective ventilation and resulting in cardiac arrest. Resuscitation by emergency bedside venoarterial extracorporeal membrane oxygenation (ECMO) permitted time to physically remove the obstructing tumor and reestablish successful ventilation and liberation from ventilatory support. We review several other reported cases of emergency ECMO to resuscitate patients with acute airway obstruction.

Survey of respiratory therapists' attitudes and concerns regarding terminal extubation.

BACKGROUND: There is little published information on the role of respiratory therapists in the process of withdrawal of mechanical ventilatory support. METHODS: We surveyed practicing respiratory therapists at 6 acute-care hospitals in a large urban area and asked about particular concerns and attitudes regarding terminal extubation. RESULTS: One hundred nineteen questionnaires were analyzed. The majority of respiratory therapists had participated in terminal extubation, but most were not regular participants in the decision-making process leading to withdrawal. CONCLUSIONS: Practicing respiratory therapists expressed a desire for a role in the decision-making process, education regarding terminal care, and more definitive orders for terminal extubation.

A laboratory evaluation of 2 mechanical ventilators in the presence of helium-oxygen mixtures.

BACKGROUND: Helium-oxygen (heliox) mixtures are being used more frequently with mechanical ventilators. Newer ventilators continue to be developed that have not yet been evaluated for safety and efficacy of heliox delivery. We studied the performance of 2 previously untested ventilators (Servo-i and Inspiration) during heliox administration. METHODS: We measured tidal volume (V(T)) delivery, gas blending, gas analyzing, and pressure stability in the presence of heliox. A heliox (80% helium/20% oxygen) tank was attached to the 50-psi air inlet. We compared the set V(T) (ie, set on the ventilator) and the exhaled V(T) (measured by the ventilator) to the delivered V(T) (measured with a lung model). Pressure measurements were also evaluated. We also compared the ventilator-setting fraction of inspired oxygen (F(IO(2))) to the F(IO(2)) measured by the ventilator and the F(IO(2)) measured with a supplemental oxygen analyzer. RESULTS: Heliox significantly affected both the exhaled V(T) measurement and the actual delivered V(T) (p < 0.001) with both the Servo-i and the Inspiration. Neither peak inspiratory pressure (in the pressure-controlled ventilation mode) nor positive end-expiratory pressure were adversely affected by heliox with either ventilator. Introducing heliox into the gas-blending systems caused only a small error in F(IO2) delivery and monitoring. CONCLUSIONS: Both Ventilators cycled consistently with heliox mixtures. In most cases, actual delivered V(T) can be reliably calculated if the F(IO2) and the set V(T) or the measured exhaled V(T) is known. With the Servo-i, at high helium concentrations the exhaled V(T) measurement was unreliable and caused a high-priority alarm condition that couldn't be disabled. A supplemental oxygen analyzer is not necessary with either device for heliox applications.