The medical emergency team (MET), a concept to prevent unexpected in-hospital cardiac arrest, was developed for adults at Liverpool Hospital, Sydney in the 1990s¹ after recognition that cardiac arrest was often preceded by warning signs and symptoms.^2–,⁴ While there have been several reports of the efficacy of MET services in adult hospitals,^5,6,7,8,9,10 no report of the impact of a MET service in a paediatric hospital has been published.

The outcome of cardiac arrest in children is dismal,¹¹ but since it is usually the culmination of prolonged hypoxaemia or hypotension, or both, there may be sufficient time to intervene and prevent it.

Review of adverse events by the Patient Safety Committee (PSC) at The Royal Children’s Hospital (RCH), Melbourne suggested that it was necessary to radically change provision of urgent medical assistance on wards. Perceived reasons for unexpected cardiac arrest and death were inability of medical and nursing staff at all levels to recognise serious illness, lack of empowerment of junior staff to obtain assistance, delay in calling for and arrival of assistance, lack of readily available medical staff, or a combination of these reasons.

METHODS

A MET service was commenced in September 2002. RCH is a specialised paediatric hospital serving a population of approximately 6 million inhabitants, of whom approximately 1.5 million are children, in southern Australia. All medical and surgical paediatric services are provided including emergency care, trauma, and cardiac surgery. It offers extra-corporeal membrane oxygenation and organ transplantation. It has an emergency retrieval service for the whole of the states of Victoria and Tasmania and for southern New South Wales.

This analysis is a quality assurance exercise conducted under statutory immunity granted to the PSC such that approval of the hospital ethics committee was not required. We excluded non-inpatients, infants in the neonatal and paediatric intensive care units, patients for whom a decision not to resuscitate had been established, those receiving palliative care, and those who had arrests under anaesthesia.

STATA 7 (StatCorp, College Station, TX) was used to analyse results. Differences in risk of arrest and death before and after MET introduction were subjected to a two-sample test of proportion. Differences in admissions to ICU were subjected to t test.

A uniform response was adopted rather than a two-tiered system of response such as one for “cardiac arrest” and another for “urgent assistance”. MET calls were regarded as potential cardiac arrests.

Instigation of MET was announced to medical officers by mail in early September 2002 along with a hospital-wide educational campaign. Daytime and night-time informal open teaching fora for nurses and medical staff were held and additional educational sessions offered. Sick Child Workshops were introduced to reinforce the clinical features of serious illness and the MET call criteria. The number of places for doctors and nurses in Advanced Paediatric Life Support courses was increased. A series of Clinical Practice Reviews for medical, nursing, and allied health staff were held in early September, November, and early December (2002) when the rationale and criteria for MET were presented and illustrative cases were reviewed. This educational period was regarded as preliminary to MET operation and as a transition period from the era of “Code Blue”. Its duration in advance was not specified, but by early December 2002 the need for intensive training had abated, representing an educational transition period of three months.

The composition of MET was initially five members comprising an ICU doctor (consultant/registrar), ICU nurse, emergency department (ED) senior doctor and nurse, and a medical registrar. However, after six months, the emergency nurses withdrew on realisation that four personnel were sufficient.

MET was initiated by calling the hospital switchboard on an emergency number. Telephonists were instructed to regard calls for any type of medical assistance as a MET call. Telephonists then: (1) issued a loud-speaker MET call (for example, “MET ward X”); (2) paged MET team members via beepers and personal data screens in ICU; and (3) telephoned ICU directly advising staff of a call and location.

At the scene, the MET provided immediate medical treatment as required, then communicated with the admitting bed-card unit members to formulate further treatment, and completed a standard MET data sheet which was collected by the investigators. To prevent discouragement of junior staff, particularly nurses, to make calls, MET members were instructed not to make adverse comments on the appropriateness or otherwise of calls and to adopt a supportive attitude.

RESULTS

DISCUSSION

Several adult hospitals have introduced MET with beneficial effects. The most recent study⁹ showed a 17% decrease in cardiopulmonary arrest from 6.5 to 5.4 per 1000 admissions. Another “before and after” trial showed a relative risk reduction of 65% for cardiac arrest, 56% for death at cardiac arrest, and 26% for hospital deaths.^5,10 It has been claimed that if this was applied nationally it would reduce Australian hospital deaths by 6000 per annum.¹³ In another hospital⁶ the incidence of unexpected cardiac arrests reduced from 3.77/1000 hospital admissions to 2.05/1000, which after adjustment for case mix was associated with a 50% reduction. Validity was challenged on the inability to separate the effects of education and instigation of MET.¹⁴ At another hospital,⁸ the incidence of in-hospital death decreased slightly from 0.74% to 0.65% and the incidence of cardiorespiratory arrest decreased slightly from 0.08% to 0.07% but with a significant decrease in unplanned ICU admissions. Another study of arrest and death between one hospital with a MET service and two others without MET did not reveal differences.⁷

In comparison, although clinically important reductions of cardiac arrest and death were observed in our “before and after” study, these were not statistically significant. This probably reflects a relatively small incidence of paediatric cardiac arrest, a small MET sample size after introduction of MET, and the fact that paediatric arrest may occur without warning. In our institution, before MET, the incidence of cardiac arrest was one twentieth of that reported in an adult hospital.⁶

The key feature of our MET service is empowerment of any nurse or paramedical personnel to request urgent medical assistance without necessarily consulting with seniors or doctors, and empowerment of any doctor to request assistance without consulting with peers or seniors. Potentially, this organisational change could lead to conflict between MET and bed-card unit members, but this was uncommonly experienced, and possibly averted by mandatory consultation of MET members with bed-card unit members to decide further management, after immediate treatment was provided.

Unlike others,¹⁴ we believe it is unnecessary to separate the effects of education and provision of emergency services with MET. Indeed, we believe twin processes of MET and education on serious illness are inextricably linked. We established a coordinated programme of education for medical, nursing, and paramedical staff in the recognition of serious illness, using MET call criteria as reference values. We believe that these interventions were an integral part of the process of introduction of MET and it is this process which contributed to reduction in unexpected cardiac arrests.

Although four arrests and deaths occurred during the three month transitional-education programme, they are not a failure of MET, but rather a reflection that education and behavioural change takes time. A similar period of transition (2 months) and a much longer preceding educational period (12 months) were described in the introduction of an adult MET service.^5,10 In that study, cardiac arrests during a 12 month educational period and during a two month transitional period were not considered in the initial analysis of the service, but in later correspondence¹⁵ it was revealed that unexpected cardiac arrest decreased to levels commensurate with those observed during MET, thus supporting our contention that education about serious illness is as important as provision of emergency services by MET.

Nearly one half of all patients subject to a MET call were admitted to ICU and unplanned admissions increased by an average of 4 per month. This increase contrasts with an adult service which observed a decrease in ICU admissions.⁸ We suspected that some MET calls made would be for relatively trivial matters, but this was not the case. In approximately 80% of cases treatment was given, and in approximately 20% only advice was given.

It is conceivable that one effect of MET may be to reduce death on wards and allow it to happen in ICU, but our observations suggest otherwise. The risk of ward death reduced from 0.12/1000 admissions to 0.06/1000 admissions, while death in all ICU patients also decreased, from 5.7% to 4.8%. These observations suggest that introduction of MET is effective in reducing unexpected cardiac arrest and mortality outside ICU and moreover does not contribute to ICU mortality.

Our study identified significant reductions in transgression of MET call criteria among patients who arrested and died before and after MET introduction, but this is subject to errors involved in retrospective analysis. It could be argued that reduction in MET transgression was partly dependent on MET criteria. We do not know the true incidence of transgression of MET call criteria among all patients and the sensitivity, specificity, and predictive power of the criteria have not yet been validated, and need research. However, it appears that we have chosen our call criteria appropriately: approximately 85% (17/20) of children in the Code Blue era who suffered cardiac arrest had transgressed MET criteria while in the MET era, a minority of calls (20%) did not warrant intervention apart from advice on ongoing management.

Establishment of a MET service may de-skill ward staff in the management of cardiac arrest. Rotation of junior medical and nursing staff through critical care areas and the integration of educational strategies within MET may offset this. Some MET members reported a disadvantage compared with the Code Blue service in that they did not know what situation was to be encountered until arrival at the scene. However, this is a relatively minor and unavoidable complication of providing preventative medical assistance.

Although this quality assurance study suggests improvement in performance, a prospective controlled study is required before a firm conclusion about the efficacy of a paediatric MET service can be made. Nonetheless, introduction of a MET service was co-incident with significant reduction of cardiac arrest and death among patients transgressing our MET call criteria.