Effect of Atypical Sleep EEG Patterns on Weaning From Prolonged Mechanical Ventilation.

Background: Approximately one-third of acute ICU patients display atypical sleep patterns that cannot be interpreted by using standard EEG criteria for sleep. Atypical sleep patterns have been associated with poor weaning outcomes in acute ICUs.

Research Question: Do patients being weaned from prolonged mechanical ventilation experience atypical sleep EEG patterns, and are these patterns linked with weaning outcomes?

Study Design And Methods: EEG power spectral analysis during wakefulness and overnight polysomnogram were performed on alert, nondelirious patients at a long-term acute care facility.

Pearls and pitfalls of respiratory testing in a patient with amyotrophic lateral sclerosis and COPD.

https://bit.ly/3Co2yR0.

/ ratio: the mismeasure of oxygenation in COVID-19.

https://bit.ly/3tNipTJ

Noninvasive strategies in COVID-19: epistemology, randomised trials, guidelines, physiology.

https://bit.ly/3pVp78e

Misconceptions of pathophysiology of happy hypoxemia and implications for management of COVID-19.

In the article "The pathophysiology of 'happy' hypoxemia in COVID-19," Dhont et al. (Respir Res 21:198, 2020) discuss pathophysiological mechanisms that may be responsible for the absence of dyspnea in patients with COVID-19 who exhibit severe hypoxemia. The authors review well-known mechanisms that contribute to development of hypoxemia in patients with pneumonia, but are less clear as to why patients should be free of respiratory discomfort despite arterial oxygen levels commonly regarded as life threatening.

Pulse oximetry.

Pulse oximetry is one of the most commonly employed monitoring modalities in the critical care setting. This review describes the latest technological advances in the field of pulse oximetry. Accuracy of pulse oximeters and their limitations are critically examined.

Effect of hyperoxic hypercapnia on variational activity of breathing.

Dysrhythmias of breathing occur in several clinical disorders, but their mechanistic basis is obscure. To understand their pathophysiology, factors responsible for the variability of breathing need to be defined. We studied the effect of hyperoxic hypercapnia (CO2) on the variational activity of breathing in 14 volunteers before and after delivering CO2 nonobstrusively via a plastic hood.

Effect of elastic loading on variational activity of breathing.

To examine the effect of elastic loading on variational activity of breathing, we studied 11 healthy subjects breathing at rest and with inspiratory elastic loads of 9 and 18 cm H2O/L, applied randomly for 1 h each. Compared with rest, a load of 18 cm H2O/L decreased gross variability, quantitated as standard deviation, of tidal volume (VT) and expiratory time (TE) (p < 0.01 in both instances) but increased that of inspiratory time (TI) (p < 0.