Long term mortality of medical emergency team patients in regional Australia

Medical emergency teams (METs) have been introduced into hospitals worldwide to improve the recognition of and response to deteriorating hospitalised patients. Australia was an early adopter of this model of care,¹ which is now mandatory and linked to hospital accreditation.

The initial aim of the MET was to intervene in the early phases of clinical deterioration to reduce in-hospital cardiac arrests and preventable mortality; benefits now reported in four systematic reviews.2, 3, 4, 5 However, subsequent research revealed that, in about one-third of cases, the MET reviewed patients with end-of-life care issues⁶ and that the in-hospital mortality of MET patients is about 25%.⁷ These observations have driven research initiatives toward understanding the factors contributing to MET calls in an effort to further improve patient outcomes and reduce the burden on the MET.⁸

Most MET literature comes from metropolitan hospitals and reports on in-hospital outcomes. There is little information from the rural setting and on longer term mortality of patients reviewed by the MET. In this issue of Critical Care and Resuscitation, Dalton and colleagues⁹ report on long term mortality of patients reviewed by the MET in a large rural hospital in Victoria, Australia. The median age of such patients was 71 years and one-third had limitations of medical treatment. Their report on associations with long term mortality is well written and executed, involves a large dataset, and includes a relatively small number of biologically plausible variables in the modelling.

Importantly, they reveal that the one-year survival of patients reviewed by the MET is 72.5%, and that age, male sex, presence of limitations of medical treatment, alteration of calling criteria for the MET, and admissions under medical units were associated with longer term mortality.

This study highlights several important findings. Firstly, the mortality of patients reviewed by the MET is high, and greater than that of age-matched patients in the community. As with all studies of the MET, it is unclear how much of this mortality is preventable. In addition, it would have been of interest to understand how the mortality of MET patients compared with matched patients who did not receive a MET review in the study hospital over the same time period. The investigators reported that only 5% of patients were admitted to the intensive care unit following MET review. This figure is similar to that reported in other studies and highlights the need to further investigate which MET patients and conditions will benefit from ICU admission.

Secondly, modification of MET criteria was associated with increased risk of long term mortality in both age groups studied. The association between altered calling criteria and patient outcome has been studied in other settings with inconsistent findings.10, 11, 12 It is intuitive that the modification of MET criteria is counterproductive to one of the important tenets of the MET: that early intervention will improve outcome. However, modifications of the MET criteria may also be a surrogate indicator of surreptitious end-of-life care practices for ward patients. As highlighted by the investigators, clinicians should take care when modifying the MET criteria, particularly if patients do not have limitations of medical treatment.

The third major finding was the issue of limitations of medical treatment and their association with increased longer term mortality. Issues around limitations of medical treatment are now a common theme within MET research and have implications for patient care before and during the MET, as well as for the training and wellbeing of staff who participate in the MET. These findings emphasise the importance of ward clinicians establishing clear goals of care before the MET arriving. The presence of uncertainty during end-of-life care MET calls has been associated with moral distress among Australian intensive care unit (ICU) MET registrars.¹³,¹⁴ These issues also highlight the importance of training ICU registrars in end-of-life care discussions during MET calls, providing support for instances of moral distress, and the need for consultant involvement in critical care outreach services.

There is need to explore the external generalisability of the findings of Dalton and colleagues⁹ and compare the mortality of MET patients with matched and contemporaneous hospitalised patients. In addition, further research should focus on the variables associated with the need for ICU admission and how such patients can be identified as early as possible. There is also a need to investigate the long term functional outcome of patients who are reviewed by the MET. Finally, there is a need to identify which patients with end-of-life care issues are highly unlikely to benefit from MET review and develop alternative strategies to manage deterioration in such patients.

Competing interests

The author declares that he does not have any potential conflict of interest in relation to this manuscript.