Association between clinically abnormal observations and subsequent in-hospital mortality: a prospective study
Introduction
Unexpected in-hospital cardiac arrest is common and associated with a high mortality rate [1], [2], [3], [4]. When cardiac arrest occurs in a general ward area, many hospitals use a “cardiac arrest team” to respond and provide immediate resuscitation. However, this approach has not been associated with an improvement in the mortality rate.
Previous studies have suggested that 66–84% of in-hospital cardiac arrests are preceded by at least one abnormal clinical observation [5], [6], [7], [8]. Traditionally, these observations are reported by nursing staff to junior medical staff, leading to delays in evaluation and definitive care.
In order to decrease the incidence of unexpected cardiac arrest, the concept of the medical emergency team (MET) has been described [9], [10], [11]. The MET consists of experienced clinicians who are called to respond immediately to patients with any abnormal clinical observations and/or laboratory findings. The rationale of a MET system is that early intervention might prevent subsequent cardiac arrest and/or unplanned intensive care admission. We reported in a previous study that the introduction of a MET significantly decreased the mortality rate of unexpected cardiac arrest in our hospital [11].
However, the clinical criteria for the paging of the MET have been based on retrospective studies of the clinically abnormal observations which have been found to precede cardiac arrest. This methodology may significantly underestimate the true incidence of these observations among hospital in-patients. Therefore, we undertook this study to determine prospectively the incidence of selected abnormal clinical observations and their association with discharge mortality status for in-hospital patients.
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Study design and methods
This study was a prospective, observational investigation at Dandenong Hospital, Melbourne, Victoria, Australia. Dandenong Hospital is a 320-bed, university affiliated teaching hospital and provides most clinical services (except elective cardiac surgery and neurosurgery) to a population of approximately 500,000 in the outer south-eastern suburbs of Melbourne, Australia. During 1999, the hospital admitted 28,000 patients and there were 520 ICU admissions.
The study was conducted as part of an
Results
During the 7-month study period, 6303 patients were admitted to the study wards, with a total of 38,115 bed-days and a mean length of stay of 6 days. During this period, 1598 abnormal bedside observations were observed in 564 patients; making the incidence of abnormal bed observations 4.2 per 100 bed-days in 8.9% patients.
The prevalence of adverse events is shown in Fig. 1. The two commonest events were the bedside observation of oxygen desaturation to less than 90% (on or off oxygen therapy),
Discussion
Recent studies have proposed that the introduction of a MET may prevent subsequent unexpected cardiac arrest and therefore decrease in-hospital mortality [10], [11]. However, the clinical criteria which have been used in previous reports for the calling of a MET have been based on clinical experience and/or retrospective data [5], [6], [7], [8], [9], [13]. Since the introduction of a MET requires additional resources, the development of accurate clinical criteria is required to avoid
References (13)
- et al.
The epidemiology of cardiac arrests in a Sydney hospital
Resuscitation
(2002) - et al.
Survival after cardiac arrest in hospital
Lancet
(1977) - et al.
Clinical antecedents to in-hospital-cardiopulmonary arrest
Chest
(1990) - et al.
The identification of risk factors for cardiac arrest and formulation of activation criteria to alert a medical emergency team
Resuscitation
(August 2002) - et al.
Survival after cardiopulmonary resuscitation in the hospital
N. Engl. J. Med.
(1983) - et al.
Outcomes of adult cardiopulmonary resuscitation at a tertiary referral centre including results of limited resuscitations
Arch. Int. Med.
(2001)
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