Level of prehospital care and risk of mortality in patients with and without severe blunt head injury

doi:10.1016/S0020-1383(02)00395-9

Injury

Volume 34, Issue 11, November 2003, Pages 815-819

https://doi.org/10.1016/S0020-1383(02)00395-9 Get rights and content

Abstract

Objectives: To determine the association between mortality and the level of prehospital care in severely injured blunt trauma patients with or without severe head injury.

Method: Retrospective review of 2010 severe blunt trauma patients (injury severity score (ISS) >15) with or without severe head injury in a tiered trauma system involving ambulance officers (basic life support (BLS) and advanced life support (ALS)) and physicians, and a Level 1 trauma centre.

Results: After adjusting for age, type of head injury, glasgow coma scale score (GCS), systolic blood pressure, ISS and prehospital time, intensive care unit (ICU) admission modified the association between level of prehospital care and mortality. In those patients without ICU admission, patients in the paramedic and physician-staffed emergency services group were more likely to die than patients in the BLS ambulance group (odds ratio (OR) 2.18, 95% confidence intervals (CI): 1.05–4.55; 4.27, 95% CI: 1.46–12.45, respectively). Among patients who survived to ICU treatment, however, there was no association between level of prehospital care and risk of mortality. Presence or absence of a head injury did not modify the risk of mortality.

Conclusions: The level of prehospital care was associated with the risk of mortality. This was modified by whether the patient survived long enough to be admitted to the ICU.

Introduction

There is ongoing controversy regarding the benefits of advanced life support (ALS) versus basic life support (BLS) in the prehospital care of severely injured trauma patients. A systematic review of prehospital ALS versus BLS failed to show a benefit for onsite ALS and concluded that ‘scoop and run’ was the optimal strategy for trauma patients [12]. However, the sub-group of patients with severe head trauma has been suggested as a group that is particularly likely to benefit from on-scene stabilisation, as early correction of hypoxia and hypotension is critical for survival [6].

The objective of this study was to determine the association between mortality and the level of prehospital care in a population of severely injured blunt trauma patients with or without severe head injury. The study was approved by the Western Sydney Area Health Human Research Ethics Committee.

Section snippets

Patients and methods

We included patients who sustained severe blunt trauma with an injury severity score (ISS) >15 [5], with or without head injury, admitted to Westmead Hospital, western Sydney, Australia between July 1986 and December 2000. These patients were identified from the hospital trauma registry. Westmead Hospital is a tertiary referral hospital providing trauma services equivalent to an American College of Surgeons Level 1 trauma centre.

The Sydney prehospital trauma system is a tiered system involving

Statistical analysis

Analysis of variance (ANOVA) was used to compare the mean ISS between the various levels of prehospital care. Factors associated with mortality were examined by using logistic regression. The predictor variables included in the initial model were: level of prehospital care, time from injury to arrival in hospital, type of injury, mechanism of injury, age, sex, ISS, GCS and systolic blood pressure. The level of prehospital care was categorised into three groups: BLS (Levels 3 and 4 ambulance),

Population

Out of 2010 patients with severe blunt injury, most were males (76%). The median age was 30 years (interquartile range 21–49 years). The most common cause was road traffic accident (1355 (67%)), falls (271 (13%)) and assault (104 (5%)). There were 713 (36%) patients with no head injury, 1047 (52%) with isolated head injury and 250 (12%) with head injury with abdominal/chest injuries.

Patients received various levels of prehospital care: non-EMS transport (5%), Level 3 ambulance (23%), Level 4

Main findings

The multivariate analysis suggests that there was no evidence that patients with severe head injuries were more likely to benefit from advanced prehospital interventions, than patients with severe injuries but who did not have severe head injury. The level of prehospital care was associated with the risk of mortality after adjusting for age, physiological derangement, severity of injury, type of injury and prehospital time. There was an increased risk of mortality in those patients receiving

Acknowledgements

We thank the Trauma Registry of Westmead Hospital for their assistance in providing data for this study and the reviewer for his/her helpful comments. All authors contributed to the design of the study. AG supervised extraction of the data, and AL analysed the results. All authors contributed to the interpretation and drafting of the paper and will act as guarantors for the paper.

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HEMS treatment is associated with a non-significantly higher risk of in-hospital mortality for patients with TBI and a non-significantly lower risk for patients without TBI. This increased risk of mortality in TBI patients is attributable to the increased prehospital time. These results indicate that HEMS does not have a positive impact on survival.
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The quality assessment of these studies, based on the recommendations of The Cochrane Collaboration, revealed that inadequate sequence generation provided the largest risk of bias followed by inadequate allocation concealment (Table 1).13 Nine trials including a total number of 16,857 trauma victims, that met our inclusion criteria, were retrieved.21–29 Table 2 provides a summary of the characteristics of these 9 studies that met our inclusion criteria.
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Level of prehospital care and risk of mortality in patients with and without severe blunt head injury

Abstract

Introduction

Section snippets

Patients and methods

Statistical analysis

Population

Main findings

Acknowledgements

Injury

Ann. Emerg. Med.

Accid. Anal. Prev.

Aggressive out-of-hospital treatment regimen for severe closed head injury in patients undergoing air medical transport

Air Med. J.

The impact of advanced prehospital emergency care on the mortality of severely brain-injured patients

J. Trauma