Elsevier

Resuscitation

Volume 159, February 2021, Pages 1-6
Resuscitation

Rapid response systems
The epidemiology of Medical Emergency Team calls for orthopedic patients in a teaching hospital: A retrospective cohort study

https://doi.org/10.1016/j.resuscitation.2020.12.006Get rights and content

Abstract

Background

Patients undergoing orthopedic surgery are at risk of post-operative complications and needing Medical Emergency Team (MET) review. We assessed the frequency of, and associations with MET calls in orthopedic patients, and whether this was associated with increased in-hospital morbidity and mortality.

Methods

Retrospective cohort study of patients admitted over four years to a University teaching hospital using hospital administrative and MET call databases.

Results

Amongst 6344 orthopedic patients, 55.8% were female, the median (IQR) age and Charlson comorbidity index were 66 years (47–79) and 3 (1–5), respectively. Overall, 54.5% of admissions were emergency admissions, 1130 (17.8%) were non-operative, and 605 (9.5%) patients received a MET call. The strongest independent associations with receiving a MET call was the operative procedure, especially hip and knee arthroplasty. Common MET triggers were hypotension (37.5%), tachycardia (25.0%) and tachypnoea (9.1%). Patients receiving a MET call were at increased risk of anemia, delirium, pressure injury, renal failure and wound infection. The mortality of patients who received a MET call was 9.8% compared with 0.8% for those who did not. After adjusting for pre-defined co-variates, requirement for a MET call was associated with an adjusted odd-ratio of 9.57 (95%CI 3.1–29.7) for risk of in-hospital death.

Conclusions

Approximately 10% of orthopedic patients received a MET call, which was most strongly associated with major hip and knee arthroplasty. Such patients are at increased risk of morbidity and in-hospital mortality. Further strategies are needed to more pro-actively manage at-risk orthopedic patients.

Introduction

Orthopedic surgery frequently involves substantial mechanical and physiological stresses that can be associated with hypovolemia, cardiac dysfunction, and alterations of vasomotor function. These stresses can in turn lead to organ dysfunction, significant morbidity and mortality. Many orthopedic procedures are performed in elderly patients with significant co-morbidities and reduced physiological reserve. Combined, these factors predispose patients to several major post-operative complications including acute kidney injury, major adverse cardiac events, postoperative pulmonary complications and delirium.1, 2

Rapid Response (RRT) or Medical Emergency Teams (MET) are an interdisciplinary team of critical care health professionals who identify and treat deteriorating postoperative patients on the ward.3 The MET is activated when a patient breaches one or more pre-defined criteria based on deteriorations in a patient’s vital signs. The introduction of METs have been associated with reductions in in-hospital cardiac arrests, all-cause hospital mortality, and post-operative complications.4, 5, 6, 7

Although METs have been shown to improve patient outcomes, there remains a paucity of data defining these patients’ baseline characteristics and peri-operative variables. Furthermore, it is desirable to better understand the epidemiology of MET events to further improve patient safety and outcomes.8 Accordingly, we undertook a retrospective study of patients admitted to a high-volume orthopedic unit in a university hospital. Specifically, we assessed the frequency of MET activations, baseline patient characteristics, the physiological trigger for the MET activation and whether requirement for a MET activation was associated with an increased risk of in-hospital complications. Finally, we determined if requirement for a MET activation was associated with an increased risk of in-hospital death.

Section snippets

Hospital setting

After Human Research Ethics approval (HREC no: LNR/16/Austin/166) we performed a retrospective cross-sectional study of adult patients admitted to the orthopedic unit between January 2012 to December 2015. The need for informed written patient consent was waived due to the observational and retrospective nature of the study. The study was conducted at Austin Health, a tertiary teaching hospital affiliated with the University of Melbourne in Melbourne, Victoria, Australia. Austin Health performs

Details of the patient cohort

Between 2012 to 2015, a total of 6344 patients were admitted under the orthopedic surgical unit. The median (IQR) age was 66 (47–79), 55.8% were female, and the median (IQR) CCI was 3 (1–5). Smoking and alcohol abuse were present in 31.0% and 1.7% of patients, respectively (Table 1). Overall, 54.5% of admissions were emergency admissions and 1130 (17.8%) were classified as non-operative (Table 2).

Details of MET call number and physiological trigger

There were 605 (9.5%) patients who received a MET call during their admission, of which 390 (64.5%)

Discussion

We conducted a retrospective observational study of patients admitted under an orthopedic surgical unit of a university hospital to evaluate the epidemiology of MET activations. We found that patients who received a MET call were older, more likely to be emergently admitted, and had a higher CCI. In addition, such patients were more likely to have an operative procedure, especially hip and knee surgery, require ICU admission, and develop a postoperative complication. Finally, we found that

Conclusions

In our hospital, approximately one in ten patients received a MET call after orthopedic surgery. Increasing age, major lower limb joint arthroplasty, and patients with a high CCI were at increased risk of requiring a MET activation. Patients who received a MET call were at increased risk of subsequently developing postoperative complications and dying in hospital. Further strategies are needed to recognize and respond to clinical deterioration and more pro-actively manage at-risk orthopedic

Conflict of interest statement

None of the authors have any conflicts of interest to declare in relation to this manuscript.

Contributions

DJ and LC conceived the study.

LC and LO conducted the data analysis.

JGRR, RZ, BM and RR conducted the data extraction.

DJ takes responsibility for the integrity of the study.

All authors contributed significantly to the drafting and revision of the manuscript.

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