Evidence-Based Mechanical Ventilatory Strategies in ARDS

Abstract

Acute respiratory distress syndrome (ARDS) remains one of the leading causes of morbidity and mortality in critically ill patients despite advancements in the field. Mechanical ventilatory strategies are a vital component of ARDS management to prevent secondary lung injury and improve patient outcomes. Multiple strategies including utilization of low tidal volumes, targeting low plateau pressures to minimize barotrauma, using low FiO2 (fraction of inspired oxygen) to prevent injury related to oxygen free radicals, optimization of positive end expiratory pressure (PEEP) to maintain or improve lung recruitment, and utilization of prone ventilation have been shown to decrease morbidity and mortality. The role of other mechanical ventilatory strategies like non-invasive ventilation, recruitment maneuvers, esophageal pressure monitoring, determination of optimal PEEP, and appropriate patient selection for extracorporeal support is not clear. In this article, we review evidence-based mechanical ventilatory strategies and ventilatory adjuncts for ARDS.

Acute respiratory distress syndrome

“…ARDS patients treated with ECMO experienced less psychological morbidity and impairment of health-related quality of life. 10 As per ELSO Registry report, estimated in-hospital mortality 90 days after VV ECMO support was 37.4% post-pandemic and 40% pre-pandemic. While COVID-19 ECMO run duration (18 e20 days) may be longer than in non-COVID-19 ECMO patients (12 days), published mortality appears to be similar in the two groups.…”

“…Improved survival is predominantly because of reduction of VILI due to more even distribution of volume than due to improved oxygenation. 10 Other advantages are improved secretion clearance and respiratory mechanics. Despite the benefits, the rate of use of prone position was as low as 16% in patients with severe ARDS in the large prospective epidemiologic Lung safe study.…”

“…Complications of prone positioning include increased intraabdominal or intracranial pressure, pressure injuries, ETT obstruction or dislodgement, difficult monitoring and performing procedures and delay in the instigation of ECMO. 10 Extracorporeal membrane oxygenation: VV ECMO improves oxygenation and CO 2 clearance and may reduce ventilator induced lung injury by allowing the reduction in the intensity of mechanical ventilation. The CESAR trial demonstrated higher survival without disability in the ECMO group versus the control group (67% vs 43%) whereas The EOLIA trial revealed a nonstatistically significant reduction in mortality in the ECMO group (35% vs 46%), despite a high rate of crossover to ECMO in the control group.…”

“…Also, early diuretic use in ARDS is independently associated with lower hospital mortality. 10 Sedation and neuromuscular blocking agents (NMBAs): sedation and analgesia are used in patients with ARDS to improve tolerance to mechanical ventilation and decrease oxygen consumption. Using sedation scales such as the Richmond Agitation-Sedation Scale (RASS) may help clinicians meet sedation goals more effectively, reducing the likelihood of over or under-sedation.…”

“…The higher the recruitment-to-inflation ratio is, the higher the potential for lung recruitment is. 10 Imaging Imaging techniques may help to identify different lung morphology and response to ventilation strategies. Chest CT allows quantitative analysis of lung: normally aerated, poorly aerated, and non-aerated tissue.…”