Monitoring patient–ventilator interaction by an end-expiratory occlusion maneuver

Excerpt

Mechanical ventilation (in combination with sedation) can completely suppress patient respiratory drive and effort. While there are circumstances under which this may be desirable, maintaining spontaneous respiratory effort is generally preferred because it reduces atelectasis, improves oxygenation, reduces pulmonary vascular resistance, and may prevent disuse diaphragm atrophy [1, 2]. Vigorous respiratory effort during assisted ventilation, however, can induce unintentional patient self-inflicted lung injury (P-SILI). Large respiratory efforts increase tidal volumes and elevate both global and regional lung stress, increasing the risk of volutrauma in the baby lung and exacerbating respiratory failure [3, 4]. Vigorous diaphragm contractions may also cause load-induced diaphragm injury [2]. Spontaneous breathing is, therefore, not a panacea, and its benefits and risks depend heavily on the magnitude of respiratory effort. Physiological principles and observational data suggest that a level of effort similar to that of resting quiet breathing is probably optimal [5]. …