Pre-hospital tracheal intubation in severe traumatic brain injury: a systematic review and meta-analysis

Prehospital intubation in patients with severe traumatic brain injury: a review

Traumatic brain injury (TBI) is a global health burden, with an incidence of 874-1005/100 000. It is a leading cause of morbidity and mortality in all ages. TBI is a heterogeneous entity, with a variety of definitions. Treatment starts at a prehospital level and aims to prevent secondary injury. Airway management is vital to prevent hypoxia, hypercapnia, and aspiration which could contribute to secondary injuries. In some systems, it is current practice to perform endotracheal intubation in the prehospital setting to secure the airway and permit controlled ventilation, as opposed to using basic maneuvers and adjuncts with supplemental oxygen. This study aims to review the effect of prehospital tracheal intubation on mortality and functional outcome in adult and pediatric patients with severe TBI compared with patients not intubated in the prehospital setting. A digital literary search of four databases using variations of the terms 'Endotracheal Intubation', 'Laryngeal Mask Airway', and 'Traumatic Brain Injury" included reports up to 31 March 2023. Of 7242, 33 studies were included. The overall risk of bias was moderate to serious. Nine studies noted an increase in mortality associated with prehospital intubation, four studies demonstrated a significant decrease in mortality and five studies reported poorer functional outcomes using various scales. Only three reports, including the only randomized controlled trial (RCT), showed improved functional outcomes with prehospital intubation. In eight studies, the prehospital intubation cohort had significantly more severe injuries. The majority of studies showed no effect on or increased mortality, and no significant association with functional outcome in patients with severe TBI who underwent prehospital intubation. However, all but one were retrospective and with a moderate to serious risk of bias. The cause of the mortality increase is uncertain and possibly a result of more severe injuries in the prehospital intubation group. The single available RCT reported improved functional outcomes with prehospital intubation but has yet to be replicated. The current evidence for prehospital intubation is uncertain in either direction, and there is a need for new prospective research, ideally with uniform outcome measures and the application of up-to-date intubation practices in the prehospital field.

Review of Ventilation in Traumatic Brain Injury

Acute brain injury is a prominent admitting diagnosis of critically ill patients, often requiring endotracheal intubation to protect the airway and resulting in respiratory failure and the need for mechanical ventilation. Following brain injury, a primary focus is avoidance of secondary insults including both hypercarbia and hypoxemia. Hyperoxemia may also result in unanticipated neurologic consequences. Brain-lung crosstalk refers to complex relationships that drive iatrogenic injury in both organs, mediated by inflammation, immunosuppression, and autonomic dysfunction. In an effort to further reduce secondary brain injury, care must be taken from time of intubation to extubation to preserve cerebral blood flow and adequate oxygen delivery. This review describes timing and methodology for intubation of a patient with brain injury, the controversies and current recommendations related to mechanical ventilation settings, and the difficulty of decision-making with extubation and tracheostomy.

Incidence and mortality related risk factors in patients with severe traumatic brain injury: A meta‑analysis

The present study aimed to clarify the onset of traumatic brain injury (TBI) and identify mortality-related risk factors in patients with severe TBI, to enable the early identification of high-risk individuals and timely implementation of prevention and treatment strategies to minimize mortality rates. Comprehensive database searches were conducted across Web of Science, PubMed, CINAHL and EMBASE, covering publications from database inception until October 17, 2023. Search terms in English included 'head trauma', 'brain trauma', 'mortality', 'death' and 'risk factor'. In total, two independent researchers screened and extracted the data on mortality onset and associated risk factors in patients with severe TBI. Meta-analysis was performed using R 4.2.2. A total of 33 cohort studies, including 71,718 patients with severe TBI, were selected for meta-analysis. The data indicated an overall mortality rate of 27.8% (95%CI: 22.5-33.2%) from database inception until October 17, 2023. Subgroup analysis revealed a mortality rate of 25.2% (95%CI: 20.2-30.1%) in developed countries, compared with 38.0% (95%CI: 21.4-54.7%) in developing countries. Additionally, the mean age of deceased patients was significantly higher compared with that of survivors (41.53±16.47). Key risk factors found to be associated with mortality included anemia [relative risk (RR), 1.42; 95%CI, 1.04-1.93], diabetes mellitus (RR, 1.40; 95%CI, 1.00-1.96), coagulopathy (RR, 4.31; 95%CI, 2.31-8.05), shock (RR, 3.41; 95%CI, 2.31-5.04) and systolic blood pressure≤90 mmHg (RR, 2.32; 95%CI, 1.65-3.27). Furthermore, pre-hospital intubation (RR, 1.48; 95%CI, 1.13-1.92),hypotension (RR, 2.04; 95%CI: 1.58, 2.63), hypoxemia (RR, 1.42; 95%CI: 1.13, 1.79), subdural hemorrhage (RR, 1.99; 95%CI: 1.50, 2.62), subarachnoid hemorrhage (RR, 1.64; 95%CI: 1.09, 2.47) and subdural hematoma (SDH; RR, 1.50; 95%CI: 1.04, 2.17). was identified to be a significant risk factor during hospitalization treatment. These results suggest that various factors, such as age, anemia, diabetes, shock, hypotension, hypoxemia, trauma scores and brain injury types, can all contribute to mortality risk in patients with severe TBI. Addressing these risk factors will likely be important for reducing mortality in this patient population.

Emergency critical care: closing the gap between onset of critical illness and intensive care unit admission

Critical illness is an exquisitely time-sensitive condition and follows a disease continuum, which always starts before admission to the intensive care unit (ICU), in the majority of cases even before hospital admission. Reflecting the common practice in many healthcare systems that critical care is mainly provided in the confined areas of an ICU, any delay in ICU admission of critically ill patients is associated with increased morbidity and mortality. However, if appropriate critical care interventions are provided before ICU admission, this association is not observed. Emergency critical care refers to critical care provided outside of the ICU. It encompasses the delivery of critical care interventions to and monitoring of patients at the place and time closest to the onset of critical illness as well as during transfer to the ICU. Thus, emergency critical care covers the most time-sensitive phase of critical illness and constitutes one missing link in the chain of survival of the critically ill patient. Emergency critical care is delivered whenever and wherever critical illness occurs such as in the pre-hospital setting, before and during inter-hospital transfers of critically ill patients, in the emergency department, in the operating theatres, and on hospital wards. By closing the management gap between onset of critical illness and ICU admission, emergency critical care improves patient safety and can avoid early deaths, reverse mild-to-moderate critical illness, avoid ICU admission, attenuate the severity of organ dysfunction, shorten ICU length of stay, and reduce short- and long-term mortality of critically ill patients. Future research is needed to identify effective models to implement emergency critical care systems in different healthcare systems.

Body composition parameters in initial CT imaging of mechanically ventilated trauma patients: Single-centre observational study

BACKGROUND

Body composition parameters provide relevant prognostic significance in critical care cohorts and cancer populations. Published results regarding polytrauma patients are inconclusive to date. The goal of this study was to analyse the role of body composition parameters in severely injured trauma patients.

METHODS

All consecutive patients requiring emergency tracheal intubation and mechanical ventilation before initial computed tomography (CT) at a level-1 trauma centre over a 12-year period (2008-2019) were reanalysed. The analysis included CT-derived body composition parameters based upon whole-body trauma CT as prognostic variables for 30-day mortality, intensive care unit length of stay (ICU LOS) and mechanical ventilation duration.

RESULTS

Four hundred seventy-two patients (75% male) with a median age of 49 years, median injury severity score of 26 and 30-day mortality rate of 22% (104 patients) met the inclusion criteria and were analysed. Regarding body composition parameters, 231 patients (49%) had visceral obesity, 75 patients had sarcopenia (16%) and 35 patients had sarcopenic obesity (7.4%). After adjustment for statistically significant univariable predictors age, body mass index, sarcopenic obesity, visceral obesity, American Society of Anesthesiologists classification ≥3, injury severity score and Glasgow Coma Scale ≤ 8 points, the Cox proportional hazard model identified sarcopenia as significant prognostic factor of 30-day mortality (hazard ratio 2.84; 95% confidence interval 1.38-5.85; P = 0.004), which was confirmed in Kaplan-Meier survival analysis (log-rank P = 0.006). In a subanalysis of 363 survivors, linear multivariable regression analysis revealed no significant associations of body composition parameters with ICU LOS and duration of mechanical ventilation.

CONCLUSIONS

In a multivariable analysis of mechanically ventilated trauma patients, CT-defined sarcopenia was significantly associated with 30-day mortality whereas no associations of body composition parameters with ICU LOS and duration of mechanical ventilation were observed.

Coronary artery calcification detected by initial polytrauma CT in severely injured patients: retrospective single-center cohort study

OBJECTIVES

Coronary artery calcifications detected by computed tomography (CT) provide prognostic relevance for vascular disorders and coronary heart disease, whereas their prognostic relevance in severely injured trauma patients remains unclear.

MATERIAL AND METHODS

All consecutive trauma patients requiring emergency tracheal intubation before initial CT at a level-1 trauma center and admission to the intensive care unit (ICU) over a 12-year period (2008-2019) were reanalyzed. The Weston score, a semiquantitative method to quantify coronary calcifications, was evaluated as a prognostic variable based upon whole-body trauma CT analysis.

RESULTS

Four hundred fifty-eight patients (74.6% male) with a median age of 49 years, median injury severity score of 26 points, 24-h mortality rate of 7.6%, and 30-day mortality rate of 22.1% met the inclusion criteria and were analyzed. Coronary artery calcification was present in 214 patients (46.7%). After adjustment for confounding factors, the Weston score was an independent predictor for 24-h mortality (hazard ratio, HR 1.19, 95% confidence interval, CI 1.06-1.32, p = .002) and 30-day mortality (HR 1.09, 95% CI 1.01-1.17, p = .027). In a subanalysis of 357 survivors, the Weston score was significantly associated with ICU length of stay (LOS) (beta weight 0.89, 95% CI 0.3-1.47, p = .003) but not with mechanical ventilation duration (beta weight 0.05, 95% CI -0.2-0.63, p = .304).

CONCLUSION

CT-detected coronary calcification was a significant prognostic factor for 24-h- and 30-day-mortality in severely injured trauma patients requiring tracheal intubation, and influenced ICU LOS in survivors.

Influence of Patient Weight on Prehospital Advanced Airway Procedure Success Rates

OBJECTIVE

Previous investigations of the relationship between obesity and difficult airway management have provided mixed results. Almost universally, these studies were conducted in the hospital setting, and the influence of patient body weight on successful prehospital airway management remains unclear. Because patient weight could be one readily identifiable risk factor for problematic airway interventions, we sought to evaluate this relationship.

METHODS

We conducted a retrospective analysis using the 2020 ESO Data Collaborative dataset. The inclusion criteria consisted of adult patients weighing >30kg with an attempted orotracheal intubation (OTI) and/or blind insertion airway device (BIAD) placement. Separate logistic regression models were developed to determine the influence of weight (dichotomized at 100 kg) on cumulative procedure success for OTI and BIAD, and linear regression models were used to identify trends for each across weight strata.

RESULTS

A total of 45,344 patients met inclusionary criteria, among which 40,668(89.7%) suffered from a medical emergency, followed by 3,130(6.9%) with traumatic injuries, and 1,546(3.4%) attributable to a combined medical-trauma etiology. Cardiac arrest occurred either prior to EMS arrival or at some point during EMS care in 38,210(84.3%) patients. OTI was attempted in 18,153(40.0%) patients, while 21,597(47.6%) had a BIAD attempt and 5,594(12.3%) had both airway types attempted. The overall cumulative insertion success rates for OTI and BIAD were 79.5% and 92.7%, respectively. Altogether, 2,711(6.0%) had no advanced airway of any type successfully placed, which represents the overall failed advanced airway rate. After controlling for patient age, sex, minority status, and call type (medical vs. trauma), weight >100kg was associated with decreased likelihood of cumulative OTI success (OR = 0.64, p < 0.001), but higher likelihood of cumulative BIAD success (OR = 1.31, p < 0.001). Cumulative OTI success was associated with a negative 0.6% linear trend per 5 kg of body weight (p < 0.001) while cumulative BIAD success had a 0.2% positive trend (p < 0.001).

CONCLUSION

This retrospective analysis of a national EMS database revealed that increasing patient weight was negatively associated with intubation success. A positive, but smaller, linear trend was observed for BIAD placement. Patient weight may be an easily identifiable predictor of difficult oral intubation and may be a consideration when selecting an airway management strategy.

The burden of head trauma in rural and remote North Queensland, Australia

BACKGROUND

Head trauma is a leading cause of death and disability worldwide. Young males, Indigenous people, and rural/remote residents have been identified as high-risk populations for head trauma, however, Australian research is limited. Our aim was to define and describe the incidence, demographics, causes, prehospital interventions, and outcomes of head trauma patients transported by aeromedical services within North Queensland, Australia. We hypothesized that young, Indigenous males living remotely would be disproportionately affected by head trauma.

METHODS

We conducted a retrospective study of all head trauma patients transferred by air to or between Townsville, Cairns, Mount Isa and Mackay Hospitals between January 1, 2016 and December 31, 2018. Patients were identified from the Trauma Care in the Tropics data registry and followed for a median 30-months post-injury. Primary endpoints were patient and injury characteristics. Secondary outcome measures were hospital stay and mortality.

RESULTS

A total of 981 patients were included and 31.1 % were Indigenous. Sixty-seven percent of injuries occurred remotely and the median time from injury to hospital was 5.8-hours (range 67-3780 min). Eighty percent of severe head injuries occurred in males (p = 0.007). Indigenous and remote patients were more likely to sustain mild injuries. The most common mechanism of injury overall was vehicle accident (37.5 %), compared to assault in the Indigenous subgroup (46.6 %, p<0.001). The overall mortality rate was 4.9 %, with older age and lower initial Glasgow Coma Score significant predictors of in-hospital mortality. Prehospital intubation was associated with a 7-fold increased risk of mortality (p = 0.056), while patients that received tranexamic acid (TXA) were almost 5-times more likely to die.

CONCLUSIONS

In North Queensland, young Indigenous males are at highest risk of traumatic head injuries. Vehicle accidents are an important preventable cause of head injury in the region. TXA administration is an important consideration for remote head trauma retrievals, in which time to emergency care is prolonged. Appropriate treatment and risk stratification strategies considering time to definitive care, severity of injury, and other prehospital patient factors require further investigation.

Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management. Part II

The Airway Management section of the Spanish Society of Anesthesiology, Resuscitation, and Pain Therapy (SEDAR), the Spanish Society of Emergency Medicine (SEMES), and the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) present the Guide for the comprehensive management of difficult airway in adult patients. Its principles are focused on the human factors, cognitive processes for decision-making in critical situations, and optimization in the progression of strategies application to preserve adequate alveolar oxygenation in order to enhance safety and the quality of care. The document provides evidence-based recommendations, theoretical-educational tools, and implementation tools, mainly cognitive aids, applicable to airway management in the fields of anesthesiology, critical care, emergencies, and prehospital medicine. For this purpose, an extensive literature search was conducted following PRISMA-R guidelines and was analyzed using the GRADE methodology. Recommendations were formulated according to the GRADE methodology. Recommendations for sections with low-quality evidence were based on expert opinion through consensus reached via a Delphi questionnaire.