title: Optimizing Prophylactic CPAP in Patients Without Obstructive Sleep Apnoea for High-Risk Abdominal Surgeries: A Meta-regression Analysis.
abstract: BACKGROUND
  Prophylactic continuous positive airway pressure (CPAP) can prevent pulmonary adverse events following upper abdominal surgeries. The present meta-regression evaluates and quantifies the effect of degree/duration of (CPAP) on the incidence of postoperative pulmonary events.
  
  
  METHODS
  Medical databases were searched for randomized controlled trials involving adult patients, comparing the outcome in those receiving prophylactic postoperative CPAP versus no CPAP, undergoing high-risk abdominal surgeries. Our meta-analysis evaluated the relationship between the postoperative pulmonary complications and the use of CPAP. Furthermore, meta-regression was used to quantify the effect of cumulative duration and degree of CPAP on the measured outcomes.
  
  
  RESULTS
  Seventy-three potentially relevant studies were identified, of which 11 had appropriate data, allowing us to compare a total of 362 and 363 patients in CPAP and control groups, respectively. Qualitatively, Odds ratio for CPAP showed protective effect for pneumonia [0.39 (0.19-0.78)], atelectasis [0.51 (0.32-0.80)] and pulmonary complications [0.37 (0.24-0.56)] with zero heterogeneity. For prevention of pulmonary complications, odds ratio was better for continuous than intermittent CPAP. Meta-regression demonstrated a positive correlation between the degree of CPAP and the incidence of pneumonia with a regression coefficient of +0.61 (95 % CI 0.02-1.21, P = 0.048, τ (2) = 0.078, r (2) = 7.87 %). Overall, adverse effects were similar with or without the use of CPAP.
  
  
  CONCLUSIONS
  Prophylactic postoperative use of continuous CPAP significantly reduces the incidence of postoperative pneumonia, atelectasis and pulmonary complications in patients undergoing high-risk abdominal surgeries. Quantitatively, increasing the CPAP levels does not necessarily enhance the protective effect against pneumonia. Instead, protective effect diminishes with increasing degree of CPAP.
authors.affiliation: Department of Anesthesia, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Preet Mohinder
authors.initials: PM
authors.lastname: Singh
authors.affiliation: Department of Anesthesia, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Borle
authors.affiliation: Department of Anesthesia, All India Institute of Medical Sciences, New Delhi, India.|Rhushabh Nursing Home, Mumbai, India.
authors.forename: Dipal
authors.initials: D
authors.lastname: Shah
authors.affiliation: Anesthesiology and Perioperative Medicine, Drexel University College of Medicine, 245 N. 15th Street, MS 310, Philadelphia, PA, 19102, USA.
authors.forename: Ashish
authors.initials: A
authors.lastname: Sinha
authors.affiliation: Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India.
authors.forename: Jeetinder Kaur
authors.initials: JK
authors.lastname: Makkar
authors.affiliation: Department of Anesthesia, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Anjan
authors.initials: A
authors.lastname: Trikha
authors.affiliation: Department of Anesthesia, Hospital of the University of Pennsylvania, Philadelphia, USA. goudrab@uphs.upenn.edu.
authors.forename: Basavana Gouda
authors.initials: BG
authors.lastname: Goudra
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000768:Anesthesia, General / Q000009:adverse effects; D045422:Continuous Positive Airway Pressure; D006801:Humans; D015994:Incidence; D008171:Lung Diseases / Q000453:epidemiology / Q000517:prevention & control*; D016017:Odds Ratio; D011014:Pneumonia / Q000453:epidemiology / Q000517:prevention & control; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control*; D011300:Preoperative Care / Q000379:methods*; D001261:Pulmonary Atelectasis / Q000453:epidemiology / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D016896:Treatment Outcome
keywords: Atelectasis; Pneumonia; Postoperative pulmonary complication; Prophylactic CPAP