Efficacy and safety of single versus repeated stepwise cycling recruitment maneuver during one-lung ventilation in patients with normal pulmonary function undergoing video-assisted thoracoscopic lung surgery: a randomized, controlled trial

Abstract

Background One-lung ventilation (OLV)-associated hypoxemia is a major concern and a challenge for the anesthesiologist. Lung recruitment maneuvers (RMs) are ventilator strategies in which the main goal is to restore the functional residual capacity and improve arterial oxygenation. Hemodynamic side effects are mainly associated with ‘fast’ RM not with ‘slow’ cycling RM and their effects are self-limited; therefore, they must be performed repetitively. Aim The aim of this study was to evaluate the efficacy and safety of single versus repeated stepwise cycling RMs during OLV in patients with normal lung function. Settings and design The study design is a randomized, double-blinded, controlled one. Patients and methods Sixty adult patients of ASA I–II who were scheduled for elective thoracoscopic lung surgery were randomized into groups C, single recruitment maneuver (SRM), and repeated recruitment maneuver (RRM) comprising 20 patients each. Group C patients received standard ventilation protocol: volume-controlled ventilation mode, VT 6 ml/kg, I : E ratio 1 : 2, positive end expiratory pressure (PEEP) 5 cmH2O, and respiratory rate 10–12 breaths/min. SRM patients received standard ventilation protocol with one alveolar RM 10 min after initiation of OLV with a PEEP of 10 cmH2O until end of surgery. RRM patients received standard ventilation protocol with first RM 10 min after initiation of OLV and then repeated every 30 min during OLV and a PEEP of 10 cmH2O until end of surgery. The following were assessed: hemodynamic parameters – heart rate, mean arterial blood pressure, and central venous pressure; respiratory mechanical parameters – peak airway pressure (Paw-peak), plateau pressure (Paw-plat), and static lung compliance; and oxygenation parameters – partial arterial oxygen tension (PaO2), PaO2/FiO2, and oxygen saturation (SpO2). Results PaO2 and PaO2/FiO2 ratio increased in the SRM and RRM groups after RM from T2 (10 min after first RM) to T4 (45 min from first RM), with a significant difference compared with group C (P<0.05). Peak and plateau airway pressures declined in the SRM and RRM groups after RM from T2 to T4, with a significant difference when compared with group C (P<0.05). Static lung compliance increased in the SRM and RRM groups after RM, with a significant difference among the groups (P<0.05). Conclusion Single or repeated cycling RM was considered effective with high safety profile in patients with normal pulmonary function undergoing thoracoscopic lung surgery using OLV.