The Use of Mechanical Insufflation-Exsufflation in Invasively Ventilated Critically Ill Adults.

Mechanical insufflation-exsufflation (MI-E) is traditionally used in the neuromuscular population. There is growing interest of MI-E use in invasively ventilated critically ill adults. We aimed to map current evidence on MI-E use in invasively ventilated critically ill adults. Two authors independently searched electronic databases MEDLINE, Embase, and CINAHL via the Ovid platform; PROSPERO; Cochrane Library; ISI Web of Science; and International Clinical Trials Registry Platform between January 1990-April 2021. Inclusion criteria were (1) adult critically ill invasively ventilated subjects, (2) use of MI-E, (3) study design with original data, and (4) published from 1990 onward. Data were extracted by 2 authors independently using a bespoke extraction form. We used Mixed Methods Appraisal Tool to appraise risk of bias. Theoretical Domains Framework was used to interpret qualitative data. Of 3,090 citations identified, 28 citations were taken forward for data extraction. Main indications for MI-E use during invasive ventilation were presence of secretions and mucus plugging (13/28, 46%). Perceived contraindications related to use of high levels of positive pressure (18/28, 68%). Protocolized MI-E settings with a pressure of ±40 cm H2O were most commonly used, with detail on timing, flow, and frequency of prescription infrequently reported. Various outcomes were re-intubation rate, wet sputum weight, and pulmonary mechanics. Only 3 studies reported the occurrence of adverse events. From qualitative data, the main barrier to MI-E use in this subject group was lack of knowledge and skills. We concluded that there is little consistency in how MI-E is used and reported, and therefore, recommendations about best practices are not possible.

Early conscious prone positioning in patients with COVID-19 receiving continuous positive airway pressure: a retrospective analysis.

The global pandemic of COVID-19 has challenged the management of hypoxaemic respiratory failure and strained intensive care unit resources. While prone positioning (PP) is an established therapy in mechanically ventilated patients with acute respiratory distress syndrome (ARDS), its role in conscious patients is less well defined. We retrospectively reviewed our experience of implementing early PP in a cohort of 24 patients with acute hypoxaemic respiratory failure due to COVID-19 who required support with continuous positive airway pressure (CPAP). The use of PP alongside CPAP significantly increased both the ROX index and arterial oxygen pressure:fractional inspired oxygen (PaO2:FiO2) ratio from baseline values (ROX index: 7.0±2.5 baseline vs 11.4±3.7 CPAP+PP, p<0.0001; PaO2:FiO2 ratio: 143±73 mm Hg baseline vs 252±87 mm Hg CPAP+PP, p<0.01), and the changes to both the ROX index and PaO2:FiO2 ratio remained significant 1 hour after cessation of proning. The mean duration of PP in the first 24 hours was 8±5 hours. Few complications were observed and PP was continued for a mean of 10±5 days. From our experience in a dedicated COVID-19 respiratory high care unit, PP alongside CPAP therapy was feasible, tolerated, safe and improved oxygenation. The use of conscious PP in ARDS warrants further investigation in randomised controlled trials.