title: The effects of different oxygen concentrations on recruitment maneuver during general anesthesia for laparoscopic surgery.
abstract: OBJECTIVE
  Recruitment maneuvers (RMs), which aim to ventilate the collaborated alveolus by temporarily increasing the transpulmonary pressure, have positive effects in relation to respiration, mainly oxygenation. Although many studies have defined the pressure values used during RM and the application period, our knowledge of the effects of different oxygen concentrations is limited. In this study, we aimed to determine the effects of different oxygen concentrations during RM on the arterial oxygenation and respiration mechanics in laparoscopic cases.
  
  
  METHODS
  Thirty-two patients undergoing laparoscopic cholecystectomy were recruited into the study. The patients were randomly divided into 2 groups. RM with a 30% oxygen concentration was performed in patients within the first group (group I, n=16), whereas patients in the second group (group II, n=16) received RM with 100% oxygen. To study respiratory mechanics, dynamic compliance (Cdyn), airway resistance (Raw), and peak inspiratory pressure were measured at 3 different times: 5 minutes after anesthesia induction, 5 minutes after the abdomen was insufflated, and 5 minutes after the abdomen was desufflated. Arterial blood gases were measured during surgery and 30 minutes after surgery (postoperative).
  
  
  RESULTS
  The average postoperative partial arterial oxygen pressure values of the patients in groups I and II were 121 and 98 mm Hg, respectively. The difference between the groups was statistically significant. In addition, the decrease in compliance from induction values after desufflation in group II was statistically significant.
  
  
  CONCLUSIONS
  On the basis of our results, maintaining oxygen concentrations below 100% during RM may be more beneficial in terms of respiratory mechanics and gas exchange.
authors.affiliation: *Department of Anesthesiology and Reanimation, Faculty of Medicine, Bezmialem Vakif University †Department of Anesthesiology and Reanimation, Faculty of Medicine, Kemerburgaz University, Istanbul, Turkey.
authors.forename: Ufuk
authors.initials: U
authors.lastname: Topuz
authors.forename: Ziya
authors.initials: Z
authors.lastname: Salihoglu
authors.forename: Banu V
authors.initials: BV
authors.lastname: Gokay
authors.forename: Tarik
authors.initials: T
authors.lastname: Umutoglu
authors.forename: Mefkur
authors.initials: M
authors.lastname: Bakan
authors.forename: Kadir
authors.initials: K
authors.lastname: Idin
mesh_terms: D000768:Anesthesia, General; D005260:Female; D006801:Humans; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000008:administration & dosage / Q000032:analysis*; D011650:Pulmonary Alveoli / Q000502:physiology
chemical_list: D010100:Oxygen