title: Drain clamping in knee arthroplasty, a randomized controlled trial.
abstract: BACKGROUND
  The purpose of this study was to determine whether repeated clamping of a suction drainage system will result in less external blood loss, blood transfusion and no increase in complications compared to a routine continuous suction drainage system. This was a randomized prospective study on patients undergoing total knee arthroplasty.
  
  
  METHODS
  Group A patients' drains were left clamped for all but 5 min (or 100 mL drainage) every 2 h for the first 6 h, then at 12-h and 24-h periods, when the drains were removed. Group B patients had continuous suction drainage. The amount of external blood loss, transfusion requirements and complications were compared between the two groups. The study group comprised 66 patients.
  
  
  RESULTS
  The mean external blood loss in the clamped drain group was 296.67 mL (standard deviation 160.28 mL) with a mean drain in situ time of 32 h, significantly less (P < 0.05) than the continuous drain group that had a mean external blood loss of 796 mL (standard deviation 250.34 mL) with a mean drain in situ time of 34 h. There was no difference in the requirements for transfusion between the two groups.
  
  
  CONCLUSIONS
  We conclude that clamping drains intermittently in hybrid total knee arthroplasty results in significantly less external blood loss with no change in morbidity or mortality. This study was a level 1 therapeutic study (i.e. with level of evidence randomized control trial with a significant difference).
authors.affiliation: Department of Orthopaedics, Alfred Hospital, Melbourne, Victoria, Australia. edenraleigh@hotmail.com
authors.forename: Eden
authors.initials: E
authors.lastname: Raleigh
authors.forename: Caroline B
authors.initials: CB
authors.lastname: Hing
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Hanusiewicz
authors.forename: Scott A
authors.initials: SA
authors.lastname: Fletcher
authors.forename: Rohan
authors.initials: R
authors.lastname: Price
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D016063:Blood Loss, Surgical; D001803:Blood Transfusion; D004322:Drainage / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications