title: Risk factors for pain and nausea following retinal and vitreous surgery under conscious sedation.
abstract: BACKGROUND
  There have been no studies examining risk factors for pain and nausea during the first day after posterior segment surgery. We performed a study to identify significant risk factors for the development of pain and nausea during the first 24 hours after outpatient vitrectomy or scleral buckle surgery.
  
  
  METHODS
  A total of 257 consecutive patients who underwent vitrectomy (192 patients), scleral buckling (57 patients) or combined vitrectomy-scleral buckling (8 patients) between July 1 and Dec. 31, 1995, were enrolled in this prospective study. The patients' age, sex and ethnicity, the duration of the procedure and the intraoperative use of minor tranquillizers, hypnotic agents, narcotic analgesics or major tranquillizers were recorded. Each patient rated his or her postoperative pain and nausea on two separate 100-mm lines. The left end of the line represented no pain (or nausea) whatsoever, and the right end of the line represented severe pain (or nausea). The distance of the recorded point from the origin of the line was used as the outcome measure for pain and nausea. All the data were analysed statistically by means of logistic regression analysis and descriptive statistics.
  
  
  RESULTS
  The median pain scores were 1.0 for the patients who underwent vitrectomy, 47.0 for those who underwent scleral buckling and 35.0 for those who underwent combined vitrectomy-scleral buckling. The median nausea scores were 14.5, 45.0 and 55.5 respectively. The only variable that was identified as a predictor of postoperative pain or nausea was the intraoperative use of narcotic analgesics: in the vitrectomy group, postoperative nausea occurred almost three times as often among patients who received these agents as among those who did not (odds ratio 2.6, p = 0.00).
  
  
  CONCLUSIONS
  The identification of the intraoperative use of narcotic analgesics as a risk factor for nausea in the first 24 hours after outpatient vitrectomy suggests that, when possible, these agents should be avoided during surgery.
authors.affiliation: Department of Ophthalmology, Toronto Hospital, Ont.
authors.forename: M
authors.initials: M
authors.lastname: Mandelcorn
authors.forename: N
authors.initials: N
authors.lastname: Taback
authors.forename: E
authors.initials: E
authors.lastname: Mandelcorn
authors.forename: C
authors.initials: C
authors.lastname: Ananthanarayan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid; D016292:Procedural Sedation / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000209:etiology*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000209:etiology*; D011446:Prospective Studies; D012164:Retinal Diseases / Q000601:surgery*; D012307:Risk Factors; D012591:Scleral Buckling; D014821:Vitrectomy
chemical_list: D000701:Analgesics, Opioid