Propofol-based anaesthesia versus sevoflurane-based anaesthesia for living donor kidney transplantation: results of the VAPOR-1 RCT.
Nieuwenhuijs-Moeke et. al. Published in BJA May 2017
Plus ça change, plus c’est la même chose – Jean-Baptiste Karr
This study explored the hypothesis that volatile anaesthetic agents provide a degree of conditioning which can attenuate potential ischaemia-reperfusion injury to an organ, in this case, the kidney. It was a prospective RCT comparing anaesthetic technique (TIVA vs Volatile) looking at biochemical markers of kidney injury (KIM-1 and NAG) as well as clinical outcomes following live donor kidney transplantation. The sevoflurane group showed higher urinary concentrations of biochemical markers of injury although this was not reflected in inferior graft outcomes.
Things we liked:
The population group was relevant to our clinical practice at the Royal Free Hospital.
The study was powered for the primary outcome measure of biochemical marker levels. The sample size calculation was very much an estimation due to insufficient published data on how these markers increased in the post-operative period. Our opinion was that, with only 17 patients in each group, the study was not powered properly for statistical significance in the secondary outcomes (including graft function). They comment in the discussion about a (statistically significant) higher incidence of T-cell mediated rejection during the first 2 years following transplantation in the TIVA group which seemed like quite a controversial statement given that the sample size was powered for another outcome. In addition, the results were the opposite of what expected (i.e the sevoflurane group had increased biochemical markers of injury) and this was explained in the discussion by a further hypothesis that actually these markers are involved in healing and repair and may be beneficial. It seemed to our group that the authors were very keen to suggest that volatile anaesthesia was the anaesthetic technique of choice even though on closer inspection the results of this study did not appear to show that.