title: The length of stay in the post-anaesthesia care unit correlates with pain intensity, nausea and vomiting on arrival.
abstract: BACKGROUND
  The benefit of the post-anaesthesia care unit (PACU) with respect to an early detection of postoperative complications is beyond dispute. From a patient perspective, prevention and optimal management of pain, nausea and vomiting (PONV) are also of utmost importance. The aims of the study were therefore to prospectively measure pain and PONV on arrival to the PACU and before discharge and to determine the relationship of pain and PONV to the length of stay in the PACU.
  
  
  METHODS
  Postoperative pain was assessed over 30 months using a numeric rating scale on admittance to the PACU and before discharge; in addition, PONV was recorded. Statistical analysis was done considering gender, age, American Society of Anesthesiologists (ASA) classification, surgical speciality, anaesthesia technique, duration of anaesthesia, intensity of nursing and length of stay.
  
  
  RESULTS
  Data of 12,179 patients were available for analysis. The average length of stay in the PACU was 5.7 ± 5.9 h, whereas regular PACU patients stayed for 3.2 ± 1.9 h and more complex IMC patients stayed for 15.1 ± 6.0 h. On admittance, 27% of patients were in pain and the number decreased to 13% before discharge; 3% experienced PONV. Risk factors for increased pain determined by multivariate analysis were female gender; higher ASA classification; general, cardiac and orthopaedic surgery and prolonged case duration. In more complex IMC patients, pain scores were higher on arrival but dropped to similar levels before discharge compared to regular PACU patients. Female gender and postoperative pain were risk factors for postoperative vomiting. Pain and PONV on arrival correlated with length of stay in the PACU. Pain- or PONV-free patients stayed almost half of the time in the PACU compared to patients with severe pain or vomiting on arrival.
  
  
  CONCLUSIONS
  The majority of PACU patients had good pain control, both on admittance and before discharge, and the overall incidence of PONV was low. Managing patients in the PACU could achieve a significant reduction of pain and PONV. The level of pain and presence of PONV on admittance to the PACU correlate with and act as predictors for increased length of PACU stay.
authors.affiliation: Institute of Anaesthesiology and Pain Medicine, Kantonsspital Winterthur, Brauerstrasse 15, 8401 Winterthur, Switzerland.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Ganter
authors.affiliation: Institute of Anaesthesiology and Intensive Care Medicine, Triemli City Hospital Zurich, Birmensdorferstrasse 497, 8063 Zurich, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Blumenthal
authors.affiliation: Institute of Anaesthesiology and Intensive Care Medicine, Triemli City Hospital Zurich, Birmensdorferstrasse 497, 8063 Zurich, Switzerland.
authors.forename: Seraina
authors.initials: S
authors.lastname: Dübendorfer
authors.affiliation: Institute of Anaesthesiology and Intensive Care Medicine, Triemli City Hospital Zurich, Birmensdorferstrasse 497, 8063 Zurich, Switzerland.
authors.forename: Simone
authors.initials: S
authors.lastname: Brunnschweiler
authors.affiliation: Institute of Anaesthesiology and Intensive Care Medicine, Triemli City Hospital Zurich, Birmensdorferstrasse 497, 8063 Zurich, Switzerland.
authors.forename: Tim
authors.initials: T
authors.lastname: Hofer
authors.affiliation: Department of Psychiatry and Psychotherapy, Statistics, University Hospital Zurich, Raemistrasse 100, 8006 Zurich, Switzerland.
authors.forename: Richard
authors.initials: R
authors.lastname: Klaghofer
authors.affiliation: Institute of Anaesthesiology and Intensive Care Medicine, Triemli City Hospital Zurich, Birmensdorferstrasse 497, 8063 Zurich, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Zollinger
authors.affiliation: Institute of Anaesthesiology and Intensive Care Medicine, Triemli City Hospital Zurich, Birmensdorferstrasse 497, 8063 Zurich, Switzerland.
authors.forename: Christoph K
authors.initials: CK
authors.lastname: Hofer
keywords: PONV; Post-anaesthesia care unit (PACU); Postoperative nausea; Postoperative pain; Postoperative vomiting