Abstract
Background: Emergency care, crucial for those with life-threatening conditions, involves immediate interventions such as emergency endotracheal intubation (ETI), which is performed in either the prehospital or emergency department (ED) settings. While neither setting is considered optimal, the belief persists that intubation in the ED yields superior success rates and better patient outcomes compared to prehospital intubation. Despite this, global practice of prehospital ETI endures, including in South Africa, where limited literature exists. In the past two decades, research has predominantly centred on emergency intubation in traumatic brain injury (TBI) cases. Emergency ETI is however not only used for TBIs, but also for non-traumatic brain pathologies (NTBPs). Given the significant differences between TBIs and NTBPs, there is uncertainty about generalizing TBI-focused findings to NTBPs. Despite these differences and the potential lack of generalizability, the prevalence of emergency ETI in NTBPs remains high, particularly in the prehospital setting. The need for further research evaluating prehospital ETI in the NTBP cohort is therefore evident. This study attempts to fulfil this need by investigating the effect of prehospital ETI on the short-term mortality of patients with NTBPs.
Methods: This study utilised a retrospective cohort design. Data related to the mortality of NTBP patients admitted to the 42 EDs of a private hospital group in South Africa was collected electronically. This data was contained in the electronic ED database of the hospital group and reflects the period of 1 January 2011 to 10 May 2022. Data analysis comprised the use of frequencies and percentages for categorical data and calculation of either the mean and standard deviation or median and interquartile range for continuous variables, depending on the distribution. The relationship between exposure and outcome variables was assessed using logistic regression analysis. Both univariate and multivariate logistic regression models were utilised in order to produce unadjusted and adjusted odds ratios and 95% confidence intervals, with all confounding variables included in the multivariate model. Finally, the absolute effects of ETI location on outcomes were calculated.
Results: In a sample of 340 cases, this study found a 10.5% relative reduction in the odds of mortality for prehospital ETI compared to ED ETI. This translated into an absolute risk difference of 3 fewer deaths per 1000. There was considerable uncertainty about this possibly beneficial effect due to relatively low precision of odds
v
ratios. Furthermore, it was found that RSI was associated with a 46% relative reduction in odds of mortality in the ED. With regard to hospital mortality, prehospital ETI was found to be associated with a 4.7% relative reduction in odds of mortality compared to ED ETI, translating into an absolute risk difference of 11 fewer deaths per 1000. Although there was uncertainty about this effect due to the relatively low precision of odds ratios, the margin of error in this estimate was less than that for ED mortality. Additionally, this study found that RSI may be associated with a 24.2% relative reduction in odds of hospital mortality. Finally, the type of NTBP was identified as a noteworthy variable affecting mortality with poisoning/overdose and seizures showing significant reductions in odds of hospital mortality compared to stroke.
Conclusion: Prehospital ETI may be associated with a marginal mortality benefit for NTBP patients compared to ED ETI. The impact of ETI location on mortality was however limited. Nevertheless, these findings challenge the widely held view that ED ETI is inherently superior to prehospital ETI. RSI appears to be the optimal ETI type for emergency intubation of patients with NTBPs, however, further research is required to confirm this suggestion. The imprecise nature of the findings obtained in this study was a notable limitation highlighting the need for prospective studies with larger sample sizes.