Peripheral tissue oxygenation and the number of organs transplanted per donor.

Current donor management practices target macrohaemodynamic parameters, but it is unclear if this leads to improvements in microvascular perfusion and tissue oxygenation; the latter may have more impact on organ status. In a recent preclinical study we determined that brain death impaired tissue perfusion and oxygen utilisation in swine while pharmacologic correction of these deficits improved organ function and reduced markers of tissue injury. As a first step in translating the preclinical findings, we conducted a prospective observational study to determine if there was an association between peripheral tissue oxygenation (measured by near-infrared spectroscopy) in deceased by neurological criteria human donors and the number of organs transplanted. In 60 donors, the mean time-weighted average of tissue oxygenation was 87.5% (standard deviation, SD, 5.2%) and the average number of organs transplanted was 3.5 (SD 2); there was a positive linear relationship between these two parameters. A 5% rise in tissue oxygenation was associated with an increase of 0.47 organs transplanted (95% confidence intervals 0.16 to 0.78) after adjusting for age (P=0.004). No such correlations were observed for the macrohaemodynamic or macro-oxygenation parameters (including arterial blood oxygenation). The results of this clinical trial are consistent with our preclinical work and support the postulate that targeting the microvasculature to improve tissue perfusion and tissue oxygen delivery in human donors has the potential to increase the quantity of organs suitable for transplant.

The effect of inhalational anaesthesia during deceased donor organ procurement on post-transplantation graft survival.

Many deceased by neurologic criteria donors are administered inhalational agents during organ recovery surgery-a process that is characterised by warm and cold ischaemia followed by warm reperfusion. In certain settings, volatile anaesthetics (VA) are known to precondition organs to protect them from subsequent ischaemia-reperfusion injury. As such, we hypothesised that exposure to VA during organ procurement would improve post-graft survival. Lifebanc (organ procurement organisation [OPO] for NE Ohio) provided the investigators with a list of death by neurologic criteria organ donors cared for at three large tertiary hospitals in Cleveland between 2006 and 2016-details about the surgical recovery phase were extracted from the organ donors' medical records. De-identified data on graft survival were obtained from the United Network for Organ Sharing (UNOS). The collated data underwent comparative analysis based on whether or not VA were administered during procurement surgery. Records from 213 donors were obtained for analysis with 138 exposed and 75 not exposed. Demographics, medical histories, and organ procurement rates were similar between the two cohorts. For the primary endpoint, there were no significant differences observed in either early (30-day) or late (five-year) graft survival rates for kidney, liver, lung, or heart transplants. Our findings from this retrospective review of a relatively small cohort do not support the hypothesis that the use of VA during the surgical procurement phase improves graft survival. Reviews of larger datasets and/or a prospective study may be required to provide a definitive answer.