Recruitment maneuver in pulmonary and extrapulmonary experimental acute lung injury

Abstract

Given the same transpulmonary pressures, RMs are more effective at opening collapsed alveoli in ALIexp than in ALIp, thus improving lung mechanics and oxygenation with limited damage to alveolar epithelium.

New and Conventional Strategies for Lung Recruitment in Acute Respiratory Distress Syndrome

“…Sustained infl ation has been shown to be eff ective in reducing lung atelectasis [29], improving oxygenation and respiratory mechanics [18,29], and preventing endotracheal suctioning-induced alveolar derecruitment [9]. However, the effi cacy of sustained infl ation has been questioned and other studies showed that this intervention may be ineff ective …”

“…Riva et al [18] compared the eff ects of sustained infl ation using a rapid high recruitment pressure of 40 cmH 2 O for 40 sec with a progressive increase in airway pressure up to 40 cmH 2 O reached at 40 sec after the onset of infl ation (so called RAMP) in paraquat-induced ALI. Th ey reported that the RAMP maneuver improved lung mechanics with less alveolar stress.…”

“…Based on this hypothesis, Kloot et al [17] investigated the eff ects of recruitment maneuvers on gas exchange and lung volumes in three experimental models of ALI: Saline lavage or surfactant depletion, oleic acid, and pneumonia, and observed improvement in oxygenation only in ALI induced by surfactant depletion. Riva et al [18] compared the eff ects of a recruitment maneuver in models of pulmonary and extrapulmonary ALI, induced by intratracheal and intraperitoneal instillation of Escherichia coli lipo polysaccharide, with similar transpulmonary pressures. Th ey found that the recruitment maneuver was more eff ective for opening collapsed alveoli in extrapulmonary compared to pulmonary ALI, improving lung mechanics and oxygenation with limited damage to alveolar epithelium.…”

“…Sustained infl ation has been shown to be eff ective in reducing lung atelectasis [29], improving oxygenation and respiratory mechanics [18,29], and preventing endotracheal suctioning-induced alveolar derecruitment [9]. However, the effi cacy of sustained infl ation has been questioned and other studies showed that this intervention may be ineff ective [30], short-lived [31], or associated with circulatory impairment [32], an increased risk of baro/volutrauma [33], a reduced net alveolar fl uid clearance [34], or even worsened oxygenation [35].…”

“…Th e most important are: 1) incrementally increased PEEP limiting the maximum inspiratory pressure [36]; 2) pressure-controlled ventilation applied with escalating PEEP and constant driving pressure [30]; 3) prolonged lower pressure recruitment maneuver with PEEP elevation up to 15 cmH 2 O and end inspiratory pauses for 7 sec twice per minute during 15 min [37]; 4) intermittent sighs to reach a specifi c plateau pressure in volume or pressure control mode [38]; and 5) long slow increase in inspiratory pressure up to 40 cmH 2 O (RAMP) [18].…”