title: Influence of caudal block on postoperative oliguria in infants undergoing bilateral ureteroneocystostomy: a retrospective analysis.
abstract: BACKGROUND
  Caudal block has been widely used in children undergoing genitourinary surgery. However, the influence of caudal block on postoperative oliguria is unclear.
  
  
  OBJECTIVE
  The aim of this study was to assess the effect of caudal block on urinary flow through the reimplanted ureter after ureteroneocystostomy and the incidence of postoperative oliguria in infants.
  
  
  METHODS
  This retrospective study analyzed the medical records of 121 infants aged less than 12 months who underwent bilateral ureteroneocystostomy for vesicoureteral reflux at a tertiary medical center. In all study infants, a ureteral catheter was placed in one of the two ureters in order to relieve the clinical consequences of transient ureteral obstruction and a urethral catheter was placed at the end of the ureteroneocystostomy procedure. Urinary output was assessed separately for each catheter. Logistic regression analysis was performed to identify the risk factors for oliguria from the urethral catheter.
  
  
  RESULTS
  Among the 121 patients, 63 (52%) received caudal block (caudal block group) and 58 (48%) did not (no caudal block group). Patient characteristics, preoperative vesicoureteral reflux grade and renal function, and intraoperative profiles were comparable between the groups. The incidence of oliguria from the urethral catheter for 8 h after the surgery was significantly higher in the caudal block group than in the no caudal block group. However, the incidence of oliguria from the ureteral catheter was comparable between the groups. In multivariate analysis, oliguria from the urethral catheter was associated with caudal block, anesthesia duration, and intraoperative dexamethasone administration. The odds for oliguria was 3.069-fold greater in patients who received caudal block than in those who did not (95%CI, 1.303-7.228, P = 0.010). On the other hand, intraoperative dexamethasone reduced the risk of oliguria.
  
  
  CONCLUSIONS
  Caudal block may be associated with postoperative oliguria in infants undergoing ureteroneocystostomy.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.|Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyun Jeong
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.|Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yong Seon
authors.initials: YS
authors.lastname: Choi
authors.affiliation: Department of Anesthesiology and Pain Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.|Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Bon-Nyeo
authors.initials: BN
authors.lastname: Koo
authors.affiliation: Department of Urology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Han
authors.affiliation: Department of Anesthesiology and Pain Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young Eun
authors.initials: YE
authors.lastname: Cho
authors.affiliation: Department of Urology, Seoul National University Children's Hospital, Seoul, Korea.
authors.forename: Young Jae
authors.initials: YJ
authors.lastname: Im
authors.affiliation: Department of Anesthesiology and Pain Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.|Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000763:Anesthesia, Caudal / Q000009:adverse effects*; D000932:Antiemetics / Q000009:adverse effects; D015331:Cohort Studies; D003559:Cystostomy / Q000009:adverse effects*; D003907:Dexamethasone / Q000009:adverse effects; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009846:Oliguria / Q000453:epidemiology* / Q000209:etiology*; D011183:Postoperative Complications / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D014513:Ureter / Q000601:surgery*; D014546:Urinary Catheterization; D014563:Urodynamics; D014718:Vesico-Ureteral Reflux / Q000601:surgery
chemical_list: D000932:Antiemetics; D003907:Dexamethasone
keywords: analgesia; anesthesia; caudal; epidural; infant; oliguria; urologic surgical procedures; vesicoureteral reflux