Effects of two alveolar recruitment maneuvers in an “open-lung” approach during laparoscopy in dogs

Abstract

ObjectivesThe aim of this study was to compare the effects of a sustained inflation alveolar recruiting maneuver (ARM) followed by 5 cmH2O of PEEP and a stepwise ARM, in dogs undergoing laparoscopic surgery.Materials and methodsTwenty adult dogs were enrolled in this prospective randomized clinical study. Dogs were premedicated with methadone intramuscularly (IM); anesthesia was induced with propofol intravenously (IV) and maintained with inhaled isoflurane in pure oxygen. The baseline ventilatory setting (BVS) was as follows: tidal volume of 15 mL/kg, inspiratory pause of 25%, inspiratory to expiratory ratio of 1:2, and the respiratory rate to maintain the end-tidal carbon dioxide between 45 and 55 mmHg. 10 min after pneumoperitoneum, randomly, 10 dogs underwent sustained inflation ARM followed by 5 cmH2O of PEEP (ARMi), while 10 dogs underwent a stepwise recruitment maneuver followed by the setting of the “best PEEP” (ARMc). Gas exchange, respiratory system mechanics, and hemodynamic were evaluated before the pneumoperitoneum induction (BASE), 10 min after the pneumoperitoneum (PP), 10 min after the recruitment (ARM), and 10 min after the pneumoperitoneum resolution (PostPP). Statistical analysis was performed with the ANOVA test (p < 0.05).ResultsStatic compliance decreased in both groups at PP (ARMc = 1.35 ± 0.21; ARMi = 1.16 ± 0.26 mL/cmH2O/kg) compared to BASE (ARMc = 1.78 ± 0.60; ARMi = 1.66 ± 0.66 mL/cmH2O/kg) and at ARM (ARMc = 1.71 ± 0.41; ARMi = 1.44 ± 0.84 mL/cmH2O/kg) and PostPP (ARMc = 1.75 ± 0.45; ARMi = 1.89 ± 0.59 mL/cmH2O/kg), and it was higher compared to PP and similar to BASE. The PaO2/FiO2, in both groups, was higher at ARM (ARMc = 455.11 ± 85.90; ARMi = 505.40 ± 31.70) and PostPP (ARMc = 521.30 ± 66.20; ARMi = 450.90 ± 70.60) compared to PP (ARMc = 369.53 ± 49.31; ARMi = 394.32 ± 37.72).Conclusion and clinical relevanceThe two ARMs improve lung function in dogs undergoing laparoscopic surgery similarly. Application of PEEP at the end of the ARMs prolonged the effects of the open-lung strategy.

Intraprocedural CT guided Navigation with Ventilatory Strategy for Atelectasis (ICNVA): a modified electromagnetic navigation bronchoscopy

“…In clinical practice, there are two common methods for lung recruitment: sustained in ation and stepwise. The stepwise method using slow-low pressure can achieve lung recruitment while reducing impact on the circulatory system [13,14]. LNVP strategy uses sustained in ation, higher PEEP, and peak pressure threshold, but this setting violates the protective lung ventilation strategy and may lead to ventilator-related lung injury [4,5,[15][16][17].…”

Management of refractory hypoxemia using recruitment maneuvers and rescue therapies: A comprehensive review

“…Besides, manual sustained hyperinflations require a shorter amount of time to perform, whereas stepwise increases in PEEP or tidal volume may prevent untoward subject responses such as straining or coughing when the depth of anesthesia is equivocal ( 31 ). Interestingly, in a recent study, sustained inflation followed by application of a PEEP of 5 cmH 2 O compared with stepwise recruitment, were equally effective in improving pulmonary function in dogs undergoing laparoscopic surgery ( 57 ).…”