[Ischaemic and pharmacologic preconditioning: desflurane reduces renal reperfusion injury in rabbits].

Background: Anaesthetic preconditioning, i.e. administration of volatile agents before ischemia, is known to have protective effects on several organs, but remains uncertain on the kidney. We developed a rabbit model for acute ischaemia-reperfusion injury, and examined a possible protective effect of desflurane preconditioning on the kidney.

Methods: Forty New Zealand male rabbits, 3 months old, weighing 2-3 kg, were anaesthetized by titrated intramuscular injections of xylazine-ketamine, mechanically ventilated and monitored. They were randomly assigned into four groups: group ischaemia (I), group ischaemic preconditioning (IPC), group desflurane preconditioning (DPC), and group SHAM (S). Groups I, IPC and DPC were subjected to 45 minutes of bilateral renal ischaemia followed by 3 hours reperfusion. Group IPC was subjected to 3 x 3 minutes ischaemia, 5 minutes before the 45-minute clamping period. Group DPC was administered one MAC desflurane for 30 minutes, before a 30-minute wash-out period. Histological analysis of the cortical zone of both kidneys were blindly performed. Tubular cell damage was graded from 1 (no lesion) to 4 (>50 % cell necrosis). Pycnotic nuclei and intratubular hyaline casts were counted on each section.

Results: DPC (1[1-2]) and S (1[1-1]) groups displayed lower histological grades than group 1(4[3-4]) (p<0.01); IPC had a grade of 3 (2-3), I and IPC groups had higher scores of pycnotic nuclei and hyaline casts than DPC and S.

Conclusion: Desflurane preconditioning was associated with a diminution of tubular cell damage. Ischaemic preconditioning did not show a significant renal protective effect.