title: Dose-Dependent Protective Effect of Inhalational Anesthetics Against Postoperative Respiratory Complications: A Prospective Analysis of Data on File From Three Hospitals in New England.
abstract: OBJECTIVE
  Inhalational anesthetics are bronchodilators with immunomodulatory effects. We sought to determine the effect of inhalational anesthetic dose on risk of severe postoperative respiratory complications.
  
  
  METHODS
  Prospective analysis of data on file in surgical cases between January 2007 and December 2015.
  
  
  METHODS
  Massachusetts General Hospital (tertiary referral center) and two affiliated community hospitals.
  
  
  METHODS
  A total of 124,497 adult patients (105,267 in the study cohort and 19,230 in the validation cohort) undergoing noncardiac surgical procedures and requiring general anesthesia with endotracheal intubation.
  
  
  METHODS
  Median effective dose equivalent of inhalational anesthetics during surgery (derived from mean end-tidal inhalational anesthetic concentrations).
  
  
  RESULTS
  Postoperative respiratory complications occurred in 6,979 of 124,497 cases (5.61%). High inhalational anesthetic dose of 1.20 (1.13-1.30) (median [interquartile range])-fold median effective dose equivalent versus 0.57 (0.45-0.64)-fold median effective dose equivalent was associated with lower odds of postoperative respiratory complications (odds ratio, 0.59; 95% CI, 0.53-0.65; p < 0.001). Additionally, high inhalational anesthetic dose was associated with lower 30-day mortality and lower cost. Inhalational anesthetic dose increase and reduced risk of postoperative respiratory complications remained significant in sensitivity analyses stratified by preoperative and intraoperative risk factors.
  
  
  CONCLUSIONS
  Intraoperative use of higher inhalational anesthetic doses is strongly associated with lower odds of postoperative respiratory complications, lower 30-day mortality, and lower cost of hospital care. The authors speculate based on these data that sedation with inhalational anesthetics outside of the operating room may likewise have protective effects that decrease the risk of respiratory complications in vulnerable patients.
authors.affiliation: 1Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA. 2Department of Anesthesiology, University of Copenhagen, Herlev Hospital, Herlev, Denmark. 3Institute of Public Health, Charité - Universitätsmedizin Berlin, Germany. 4Klinik für Anästhesiologie und Intensivmedizin, Universitaetsklinikum Essen, Essen, Germany.
authors.forename: Stephanie D
authors.initials: SD
authors.lastname: Grabitz
authors.forename: Hassan N
authors.initials: HN
authors.lastname: Farhan
authors.forename: Katarina J
authors.initials: KJ
authors.lastname: Ruscic
authors.forename: Fanny P
authors.initials: FP
authors.lastname: Timm
authors.forename: Christina H
authors.initials: CH
authors.lastname: Shin
authors.forename: Tharusan
authors.initials: T
authors.lastname: Thevathasan
authors.forename: Anne K
authors.initials: AK
authors.lastname: Staehr-Rye
authors.forename: Tobias
authors.initials: T
authors.lastname: Kurth
authors.forename: Matthias
authors.initials: M
authors.lastname: Eikermann
mesh_terms: D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005260:Female; D017721:Hospital Costs; D017052:Hospital Mortality; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D008875:Middle Aged; D011014:Pneumonia / Q000517:prevention & control*; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control*; D057216:Propensity Score; D011446:Prospective Studies; D011654:Pulmonary Edema / Q000453:epidemiology / Q000517:prevention & control*; D012131:Respiratory Insufficiency / Q000453:epidemiology / Q000517:prevention & control*
chemical_list: D018685:Anesthetics, Inhalation