Comparison of the effects of two anaesthetic combinations in rabbits on some neutrophil functions in vitro

Abstract

Tissue injury during surgery as well as anaesthesia can lead to modulation of neutrophil function. The aim of this study was to assess how two types of anaesthesia, i.e. combination of ketamine/midazolam/propofol (Group I) and ketamine/propofol (Group II) infl uenced neutrophil function during and 24 h after operation in rabbits. Blood samples were taken prior to anaesthesia, at 30 and 60 min, and 24 h after starting the experiment. At these time points, degranulation and free radical generation were assessed in both groups. After 30 min of anaesthesia, we observed a decrease in elastase release from 50.96±0.71% to 26.52±4.85% in Group I and from 51.00±0.7% to 41.00±5.48% in Group II, respectively. In subsequent measurements, the elastase level increased to values lower than before starting anaesthesia. The myeloperoxidase (MPO) release decreased signifi cantly after 30 min of anaesthesia in Group I, then increased to the value similar to the pre-anaesthetic level after 60 min. MPO level in Group II also decreased after 30 min but to a lesser degree, and then after 1 h MPO slightly exceeded the pre-anaesthetic level. In both groups, 24 h after the start anaesthesia the values obtained decreased, but remained at a level higher than at the time before anaesthesia. We observed a decrease in alkaline phosphatase (ALKP) levels in both studied groups after 30 min of anaesthesia (from 24.77±5.9% to 15.7±2.1% and from 23.6±1.14% to 10.6±0.89%, in Groups I and II, respectively), with a subsequent increase after 60 min. In Group I, we observed a signifi cant (P<0.01) decrease in NO production 30 min after the start of anaesthesia. After increasing to the pre-anaesthetic level, the NO level was almost constant in both subsequent measurements. In Group II, NO level decreased 30 min after the onset of anaesthesia and then increased, reaching a slightly higher level than at the start of anaesthesia. The superoxide generation by neutrophils from rabbits of both groups decreased after 30 min of anaesthesia and then rose. Because the anaesthetic combinations used alter neutrophil function only transiently, both of them would be applied in surgery in rabbits without the risk of disturbance to the healing process.