Unveiling alveolar recruitment: the fascinating trail between theory and practice

Excerpt

Alveolar recruitment as well as avoidance of de-recruitment are well-accepted fundamental goals of the ventilatory management of ALI/ARDS patients, albeit even in the recent past the search for a definite strategy of recruitment and of positive end-expiratory pressure (PEEP) setting was the source of partially heated debates [1, 2, 3]. Compared with such fundamental controversies, the question of how to quantify alveolar recruitment may appear as a marginal sub-topic, especially because techniques based on CT scans, which is considered the gold standard [4], or others relying on respiratory mechanics [5, 6], have been fairly well established as research tools for decades. Nevertheless, even these techniques are limited mainly due to the lacking possibility of continuous measurements, in the case of CT to the need of transporting patients to the imaging facilities, and to the fairly complicated methods. In contrast, arterial oxygenation did not always prove to be strongly related to alveolar recruitment as detected by means of CT [7], the variability of the results being possibly dependent on the CT technique used [8]. …