Effect of recruitment maneuver on respiratory mechanics in laparoscopic sleeve gastrectomy operations

EFFECT OF "RECRUITMENT" MANEUVER ON RESPIRATION MECHANICS IN LAPAROSCOPIC SLEEVE GASTRECTOMY OPERATIONS Background and Aim: Bariatric surgery is one of the most effective treatment methods for obesity. Laparoscopic Sleeve Gastrectomy (LSG) is a new approach in the surgical treatment of morbid obesity. Obesity and anesthesia, separately from each other, constitute a tendency for atelectasis and decrease in functional residual capacity. Pneumoperitoneum applied in laparoscopic surgeries is related to atelectasia and decrease in lung compliance. One of the most important aims of anesthesia method in anesthetized obese patients is keeping open the airway and alveoli. Alveolar "recruitment" maneuvers result in a sustained increase in airway pressure that serves to recruit collapsed alveoli and improve arterial oxygenation. The aim of our study is to investigate the effect of "recruitment" maneuver on respiratory mechanics and arterial blood gases in LSG operation applied in morbid obese patients. Material and Method: A total of 60 American Society of Anesthesiologist (ASA) II-III patients between 18-65 years of age, with a body mass index between 40-55 and scheduled for elective LSG were included in our study. Standard anesthesia induction and maintenance was applied to all of our patients. Patients were separated into two groups by drawing lots. Mechanical ventilation of 6 mL.kg-1 tidal volume in accordance with adjusted body weight, 8 cmH2O positive end-expiratory pressure (PEEP) with respiratory rate to maintain end-tidal carbon dioxide (EtCO2) between 30- 35 mmHg, fractional inspired oxygen (FiO2) %40 and 4 L.min-1 fresh gas flow, was applied to all patients. Manual "recruitment" maneuver was applied 5minutes after desufflation to the patients in recruitment group (n=30) under 100% oxygen with 40 cmH2O pressure for 40 seconds. No operation additional to mechanical ventilation was applied in the control group (n=30). After operation, respiratory mechanics (compliance and airway pressures) and arterial blood gas evaluations of both groups were made in the 10th minute after induction, 10th minute after insufflation, 5th minute after desufflation and 15th minute after desufflation. Also, arterial blood gas evaluation was made in recovery room 30th minute after operation. Results: In our study, it was demonstrated that oxygenation increased significantly in the recruitment group after recruitment. In 30th minute values after operation; partial arterial oxygen pressure (PaO2) values were found significantly high and partial arterial carbon dioxide 3 pressure (PaCO2) values were found significantly low (in the normal ranges) in the recruitment group compared to the control group. It was detected that, the compliance decreased with pneumoperitoneum in both groups and were over the initial values after desufflation. In the 15th minute measurements after desufflation, compliance was detected higher in the recruitment group. It was detected that there was an increase in PIP values with pneumoperitoneum in both groups and after desufflation this returned to the levels before pneumoperitoneum. In the perop and postop periods there was not any change in the hemodynamic state of the patients associated with recruitment maneuver and there was no any unexpected effect or complication. Conclusion: Application of "recruitment" maneuver in addition to PEEP application may be safely used as a more effective method to improve respiratory mechanics and the arterial blood gases in morbid obese patients who had LSG operation.