title: Prevalence and predictive factors of urinary retention assessed by ultrasound in the immediate post-anesthetic period.
abstract: OBJECTIVE
  Urinary retention is a common condition in the post-anesthetic care unit (PACU). Vesical overdistension and consequent damage of the detrusor muscle of the urinary bladder represent situations that can be prevented. The ultrasound allows the reliable measurement of the urinary volume, determining the prevalence of postoperative vesical distension. The objective of the present study was to determine the prevalence of postoperative urinary retention and identify independent predictive factors.
  
  
  METHODS
  Two-hundred and fifty-seven patients admitted to the PACU were included prospectively in this study. Parameters collected included: age, gender, physical status, site of surgery, type of anesthesia, time of the surgery and anesthesia, use of opioids, volume of fluids administered, and history of urinary symptoms. Vesical volumes were measured by ultrasound after admission and upon discharge from the PACU. The criteria to characterize urinary retention were: vesical volume equal or higher than 600 mL associated with incapacity of spontaneous micturition for 30 minutes after the diagnosis. Univariate and multivariate analyses were used to indentify independent predictive factors.
  
  
  RESULTS
  Urinary retention was observed in 19 patients (7.39%), independent predictive factors identified included urinary volume equal to or greater than 360 mL upon admission to the PACU (Mantel-Haenszel Chi-square test (1 dF) = 18.76; p < 0.01), with an odds ratio of 9.82 (95% confidence interval = 3.26-29.55) and surgeries of the lower limbs (Mantel-Haenszel Chi-square test (1 dF) = 5.33; p = 0.02), with odds ratio of 4.33 (95% confidence interval = 1.34-14.02).
  
  
  CONCLUSIONS
  Due to the prevalence of urinary retention, we suggest that a systematic evaluation of the urinary volume at the PACU should be done, especially in those patients with predictive factors.
authors.affiliation: Hospital Governador Celso Ramos. adalmago@hotmal.com
authors.forename: Adilson José
authors.initials: AJ
authors.lastname: Dal Mago
authors.forename: Pablo Escovedo
authors.initials: PE
authors.lastname: Helayel
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bianchini
authors.forename: Henrique
authors.initials: H
authors.lastname: Kozuki
authors.forename: Getúlio Rodrigues
authors.initials: GR
authors.lastname: de Oliveira Filho
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000758:Anesthesia; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D014463:Ultrasonography; D016055:Urinary Retention / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D055815:Young Adult