Adaptation of a respiratory service to provide CPAP for patients with COVID-19 pneumonia, outside of a critical care setting, in a district general hospital.

Introduction: One-hundred and forty patients at Croydon University Hospital received continuous positive airway pressure (CPAP) on a specialist respiratory ward, as a bridge to invasive mechanical ventilation (IMV) or as a ceiling of care for COVID-19. This retrospective study aimed to outline service expansion, patient characteristics and explore risk factors in outcomes.

Results: Mean age of patients on CPAP was 64 years (standard deviation 12).

Muscle fatigue examined at different temperatures in experiments on intact mammalian (rat) muscle fibers.

In experiments on small bundles of intact fibers from a rat fast muscle, in vitro, we examined the decline in force in repeated tetanic contractions; the aim was to characterize the effect of shortening and of temperature on the initial phase of muscle fatigue. Short tetanic contractions were elicited at a control repetition rate of 1/60 s, and fatigue was induced by raising the rate to 1/5 s for 2-3 min, both in isometric mode (no shortening) and in shortening mode, in which each tetanic contraction included a ramp shortening at a standard velocity. In experiments at 20 degrees C (n = 12), the force decline during a fatigue run was 25% in the isometric mode but was significantly higher (35%) in the shortening mode.