title: Of rough starts and smooth finishes: correlations between post-anesthesia care unit and postoperative days 1-5 pain scores.
abstract: OBJECTIVE
  The goal of this project was to explore the association between post-anesthesia care unit (PACU) pain scores recorded within the first and second hour of the end of surgery with maximum and median pain scores recorded on postoperative days (PODs) 1 through 5.
  
  
  METHODS
  This study was a retrospective cohort study of clinically documented pain scores in a mixed surgical population.
  
  
  METHODS
  This study was set in a single tertiary-care teaching hospital over a 1-year time period.
  
  
  METHODS
  All patients were adult patients undergoing a single, non-ambulatory, non-obstetric surgical procedure.
  
  
  METHODS
  Pain scores, measured using the numerical rating scale, from PODs 0 through 5 were obtained from an integrated data repository. Kendall's Tau-b correlations were then calculated between maximum pain scores occurring within each of the two PACU time periods and maximum and median pain scores in each of the five ensuing PODs.
  
  
  RESULTS
  A total of 349,797 pain scores from 8,332 patients were reviewed. Correlations between maximum pain score by time period demonstrated a significant and high correlation at Tau-b = 0.86, between 1-hour PACU pain scores and 2-hour PACU pain scores. However, the correlation of maximum pain scores recorded in the PACU with those recorded on PODs 1 through 5 was significantly lower, ranging from 0.19 to 0.27. The correlation of maximum PACU pain score with median pain scores recorded on PODs 1 through 5 ranged from 0.22 to 0.29. The correlation structures of the PODs 1 through 5 median pain scores may be consistent with an autoregressive pattern.
  
  
  CONCLUSIONS
  Maximum scores measured within the PACU likely reflect a set of circumstances distinct from those experienced on PODs 1 through 5.
authors.affiliation: Department of Anesthesiology, University of Florida, Gainesville, Florida, USA.
authors.forename: Patrick James
authors.initials: PJ
authors.lastname: Tighe
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Harle
authors.forename: Andre Pierre
authors.initials: AP
authors.lastname: Boezaart
authors.forename: Haldun
authors.initials: H
authors.lastname: Aytug
authors.forename: Roger
authors.initials: R
authors.lastname: Fillingim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000762:Anesthesia Recovery Period; D015331:Cohort Studies; D005260:Female; D006757:Hospital Units; D006801:Humans; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000453:epidemiology*; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult
keywords: Anesthesia; Correlation Structure; Pain; Recovery Room; Surgery; Trajectory