The effects of propofol or halothane on free radical production after tourniquet induced ischaemia-reperfusion injury during knee arthroplasty.
BACKGROUND
Ischaemia-reperfusion injury following tourniquet release is a good in vivo model for evaluating acute conditions. The aim of the study was to investigate the effects of propofol or halothane anaesthesia on oxidative stress by determining malondialdehyde (MDA) levels during knee arthroplasty.


METHODS
Thirty patients undergoing orthopaedic surgery were divided into two groups. Anaesthesia was induced with either fentanyl 100 microg and propofol 2 mg kg(-1) (Group 1) or fentanyl 100 microg and thiopentone 5 mg kg(-1) (Group 2) and maintained with infusion of propofol in Group 1 or inhalation of halothane in Group 2. ECG, SpO2, EtCO2, and mean arterial pressure (MAP) were monitored. Venous and arterial blood samples were obtained at different measurement times for MDA and blood gas analyses.


RESULTS
There was a significant decrease in MAP in the 1st and 5th minutes after tourniquet release (ATR) when compared with the 5th minute before tourniquet release (BTR) in both groups. Heart rate (HR) increased significantly in the 1st minute ATR in Group 1 only. EtCO2 increased significantly in the 1st and 5th minutes ATR, SpO2 decreased in the 1st minute ATR in both groups. There was a significant decrease in pH and increase in pCO2 at 1, 5 and 30 min ATR in both groups. pO2 values decreased in the 1st minute ATR in Group 1 only and returned to control values at 5 min ATR and decreased at 30 min ATR in the recovery room in both groups. The differences in SaO2 were similar to SpO2. MDA levels decreased before and after release of tourniquet when compared to baseline in both groups. However, there was a statistically significant decrease only in Group 1.


CONCLUSIONS
Propofol may be a good choice of anaesthetic when an ischaemia-reperfusion injury is anticipated as in orthopaedic surgery requiring a tourniquet, due to its antioxidant properties, but halothane needs further study.
Aldemir
O
O
Department of Anaesthesiology, Gazi University, School of Medicine, Ankara, Turkey.
Celebi
H
H
Cevik
C
C
Duzgun
E
E
D000368:Aged; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D001178:Arthroplasty; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D005609:Free Radicals / Q000378:metabolism*; D006221:Halothane / Q000494:pharmacology*; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D018384:Oxidative Stress / Q000187:drug effects; D010100:Oxygen / Q000097:blood; D015742:Propofol / Q000494:pharmacology*; D015427:Reperfusion Injury / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology; D017392:Thiobarbituric Acid Reactive Substances; D014111:Tourniquets
D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D005609:Free Radicals; D017392:Thiobarbituric Acid Reactive Substances; D002245:Carbon Dioxide; D008315:Malondialdehyde; D010100:Oxygen; D006221:Halothane; D015742:Propofol