Peri-operative medical emergency team activation in liver transplantation

The medical emergency team (MET) system functions to promptly identify acutely ill patients at-risk for deterioration. Liver transplant (LT) patients are at-risk for serious post-operative complications.

To evaluate the characteristics of MET activations in post-operative LT patients and to compare clinical outcomes with case-matched controls.

Retrospective case-control study of all adult patients receiving LT over a 3-year period. Cases were defined as post-operative LT patients who received a MET activation. Controls were defined as LT patients who did not receive a MET activation during the same period, and were matched for age, sex and pre-operative Model for End-Stage Liver Disease (MELD) score.

We found 10.3% (n=18) of LT patients received a total of 26 MET activations (149.4 per 1000 admissions). The mean (SD) age was 54 (9.5) years and 52% were females. There were no differences in baseline characteristics or underlying liver disease between groups, except pre-operative hepatic encephalopathy was more common among cases (55.6% vs 22.2%, p=0.03). Of the MET activations, respiratory distress was the most common 'trigger' (87.7%). In 42.3% (n=11) of the activations, MET criteria had been fulfilled in the 24 h preceding. In these MET activations, patients were characterised as tachypnoeic, hypoxaemic, hypotensive, tachycardic and/or oligo-anuric. MET patients had significantly longer ICU and hospital lengths of stay, along with greater rate of unplanned ICU re-admission (83.3% vs 13.9%, p<0.0001) compared with controls. MET patients also had higher in-hospital and 1-year post-discharge mortality (p=0.10, <0.001, respectively) compared with controls.

LT patients with post-operative complications prompting MET activation had higher morbidity and mortality compared with controls; however, the MET may have been under-utilised and/or delayed. Further prospective multi-centre investigation is warranted.