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

Mechanical insufflation-exsufflation (MI-E) is traditionally used in the neuromuscular popula-tion. 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 identi-fied, 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.