title: Triggers of blood transfusion in percutaneous nephrolithotomy.
abstract: OBJECTIVE
  To determine the triggers of blood transfusion in patients undergoing percutaneous nephrolithotomy (PCNL).
  
  
  METHODS
  Observational study.
  
  
  METHODS
  The Aga Khan University Hospital, Karachi, from 1988 to 2007.
  
  
  METHODS
  The percutaneous surgery database was retrospectively reviewed to identify patients with postoperative haemorrhage and need for blood transfusion. Blood loss was estimated by the postoperative drop in haemoglobin factored by the quantity of any blood transfusion. Various patients and procedure-related factors were assessed for association with total blood loss or blood transfusion requirement using stepwise univariate, forward multivariate regression analysis.
  
  
  RESULTS
  A total of 326 procedures were performed in 316 patients. Two hundred and thirty two procedures were included in the study. There were 167 males and 65 females. The mean age was 41+14 years. The mean haemoglobin drop was 1.68 +1.3 gm/dL. The overall blood transfusion rate was 14.2%. Stepwise multivariate regression analysis showed that female gender (p = 0.003), staghorn stone (p = 0.023), stone fragmentation with ultrasound (p = 0.054) and chronic renal failure (p = 0.001) were significantly predictive of the need for blood transfusion.
  
  
  CONCLUSIONS
  Chronic renal failure, female gender, presence of staghorn calculi and stone fragmentation using ultrasonic device were predictive of blood transfusion in this cohort of patients.
authors.affiliation: Department of Surgery, Section of Urology, The Aga Khan University Hospital, Karachi.
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Zehri
authors.forename: Syed Raziuddin
authors.initials: SR
authors.lastname: Biyabani
authors.forename: Khurram Muthair
authors.initials: KM
authors.lastname: Siddiqui
authors.forename: Amanullah
authors.initials: A
authors.lastname: Memon
mesh_terms: D000328:Adult; D001803:Blood Transfusion; D005260:Female; D006801:Humans; D008297:Male; D053040:Nephrolithiasis / Q000453:epidemiology / Q000628:therapy*; D009403:Nephrostomy, Percutaneous / Q000379:methods*; D010154:Pakistan / Q000453:epidemiology; D019106:Postoperative Hemorrhage / Q000628:therapy*; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors