title: The effects of tourniquet on intraocular pressure during knee surgery.
abstract: BACKGROUND
  In this prospective study we aimed at examining the effects of pneumatic tourniquet on intraocular pressure during elective knee surgery.
  
  
  METHODS
  Twenty patients undergoing elective knee surgery under general anesthesia with tracheal intubation were inluded the study. Anesthesia was induced with pentothal, rocuronium and fentanyl, then maintained with sevoflurane and nitrous oxide in oxygen. Intraocular pressure measurements were performed at 7 time points; awake (baseline), following induction, following tracheal intubation, just before tourniquet inflation, after the inflation of tourniquet, before tourniquet deflation, after the deflation of the tourniquet.
  
  
  RESULTS
  Baseline IOP was 15 +/- 1 mmHg. Following the induction of anesthesia IOP was reduced significantly (12 +/- 1 mmHg) (p < 0.05), then increased to 16 +/- 1 mmHg after tracheal intubation (p < 0.05). IOP was significantly higher after tourniquet inflation compared with just before (13 +/- 1 mmHg vs 16 +/- 1 mmHg recpectively) (p < 0.05). There was no significant difference between the IOP measurements after the inflation and before the deflation of the tourniquet (p > 0.05). The lowest value was 12 +/- 0 mmHg measured after the tourniquet loosened and it was significant compared with the baseline and the measurement performed before deflation of the tourniquet (16 +/- 0 mmHg) (p < 0.05).
  
  
  CONCLUSIONS
  Pneumatic tourniquet may cause a significant IOP increase in patients performing knee surgery under general anesthesia.
authors: Abant Izzet Baysal University Medical Faculty, Department of Anesthesiology, Bolu, Turkey. gulcune@yahoo.com.tr
authors: Nebahat Gulcu
authors: NG
authors: Bulut
authors: Kazim
authors: K
authors: Karaaslan
authors: Kutay E
authors: KE
authors: Ozturan
authors: Husamettin
authors: H
authors: Cakici
authors: Hasan
authors: H
authors: Kocoglu
mesh_terms: D001794:Blood Pressure; D005260:Female; D006339:Heart Rate; D006801:Humans; D007429:Intraocular Pressure; D007717:Knee / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014111:Tourniquets