Risky intubations in the Emergency Department

Background

Uncontrolled haemorrhage remains the most common cause of potentially preventable death after trauma. The management of the airway in the emergency department (ED) for trauma patients with major bleeding presents a critical challenge. Premature endotracheal intubation (ETI) in such patients can exacerbate shock and precipitate extremis, necessitating a careful balance of priorities where intubation may be deferred in favour of rapid resuscitation and transport to the operating room (OR). This week, we have an observational study that compares outcomes for trauma patients intubated in the ED or OR. The abstract is below, but as always, please read the paper yourself.

Abstract – Emergency department versus operating room intubation of patients undergoing immediate hemorrhage control surgery^​1​

Background: Hemorrhage control surgery is an essential trauma center function. Airway management of the unstable bleeding patient in the emergency department (ED) presents a challenge. Premature intubation in the ED can exacerbate shock and precipitate extremis. We hypothesized that ED versus operating room intubation of patients requiring urgent hemorrhage control surgery is associated with adverse outcomes at the patient and hospital-levels.

Methods: Patients who underwent hemorrhage control within 60 minutes of arrival at level 1 or 2 trauma centers were identified (National Trauma Data Bank 2017-2019). To minimize confounding, patients dead on arrival, undergoing ED thoracotomy, or with clinical indications for intubation (severe head/neck/face injury or Glasgow Coma Scale score of ≤8) were excluded. Two analytic approaches were used. First, hierarchical logistic regression measured the risk-adjusted association between ED intubation and mortality. Secondary outcomes included ED time, units of blood transfused, and major complications (cardiac arrest, acute respiratory distress syndrome, acute kidney injury, sepsis). Second, a hospital-level analysis determined whether hospital tendency ED intubation was associated with adverse outcomes.

Results: We identified 9,667 patients who underwent hemorrhage control surgery at 253 trauma centers. Patients were predominantly young men (median age, 33 years) who suffered penetrating injuries (71%). The median initial Glasgow Coma Scale and systolic blood pressure were 15 and 108 mm Hg, respectively. One in five (20%) of patients underwent ED intubation. After risk-adjustment, ED intubation was associated with significantly increased odds of mortality, longer ED time, greater blood transfusion, and major complications. Hospital-level analysis identified significant variation in use of ED intubation between hospitals not explained by patient case mix. After risk adjustment, patients treated at hospitals with high tendency for ED intubation (compared with those with low tendency) were significantly more likely to suffer in-hospital cardiac arrest (6% vs. 4%; adjusted odds ratio, 1.46; 95% confidence interval, 1.04-2.03).

Conclusion: Emergency department intubation of patients who require urgent hemorrhage control surgery is associated with adverse outcomes. Significant variation in ED intubation exists between trauma centers not explained by patient characteristics. Where feasible, intubation should be deferred in favor of rapid resuscitation and transport to the operating room.

Emergency department versus operating room intubation of patients undergoing immediate hemorrhage control surgery. Dunton Z, Seamon M, Subramanian M.
J Trauma Acute Care Surg

What kind of study is this?

This is a retrospective cohort study of adult patients who underwent urgent haemorrhage control surgery at level 1 or 2 trauma centres, as recorded in the National Trauma Data Bank (NTDB) from 2017 to 2019. The study aims to evaluate the association between the location of intubation (ED vs. OR) and outcomes such as mortality and major complications. As discussed below, retrospective cohort studies are prone to bias, but may provide useful information to inform future studies.

Tell me about the patients

The study cohort included patients who required urgent haemorrhage control surgery within 60 minutes of arrival at a trauma centre. Exclusions were made for patients with severe head, face, or neck injuries, those with a Glasgow Coma Scale (GCS) score ≤ 8, and those who underwent ED thoracotomy. The study focused on patients who did not have overt clinical indications for intubation, to minimise confounding by indication.

• Number of patients: 9,667
• Demographics: Predominantly young men (median age: 33 years)
• Injury type: 71% suffered penetrating injuries
• Initial GCS and SBP: Median GCS of 15 and systolic blood pressure (SBP) of 108 mm Hg

What were the outcomes?

• Primary outcome: In-hospital mortality
• Secondary outcomes:
  • Total ED time
  • Units of blood transfused within the first 4 hours
  • Major complications (cardiac arrest with CPR, acute kidney injury (AKI), acute respiratory distress syndrome (ARDS), ventilator-associated pneumonia (VAP), and severe sepsis)

What are the main results?

The study identified significant differences in outcomes based on the location of intubation:

• Mortality: Patients intubated in the ED had higher mortality (17.4%) compared to those intubated in the OR (7.1%).
• ED Time: Longer median length of time for ED intubation (31 minutes vs. 22 minutes).
• Blood Transfusion: Greater median units of blood transfused for ED intubation (6 units vs. 4 units).
• Major Complications: Higher rates of cardiac arrest, AKI, ARDS, VAP, and sepsis for patients intubated in the ED.

What was really interesting was that when the authors controlled for patient mix (via characterising the nature of the trauma centres, the differences still exist. This suggests that it may be that culture and local beliefs/procedures differ between centres and that this affects patient outcomes. It looks like different centres have different appetites for ED intubation for similar patients, and I think that’s a worry.

I have worked with people over the years who are very keen on doing procedures, and perhaps that influences their decisions. As we have said many times on the blog, there are two universal reasons for any procedure. One is that the patient needs it, and the other is that you want to do it. Ideally, both should be a yes, but it’s not acceptable for it to just be the latter, now that’s a leap from the data to an opinion, and so may be incorrect, but it’s an interesting observation in the data.

In essence, the authors describe a ‘striking difference’ in intubation rates between institutions that cannot be explained by patient mix (on the available data).

What are the strengths and weaknesses of this design?

Strengths:

• Large Sample Size: The study’s large cohort (9,667 patients) is good and has allowed a degree of statistical power.
• Exclusion Criteria: Patients who suffered prehospital cardiac arrest and those presenting dead on arrival or with nonsurvivable injuries ([AIS] score = 6) were excluded.
• Risk Adjustment: Multivariable logistic regression models were used to adjust for patient baseline and injury characteristics.

Limitations:

• Retrospective Design: The study’s retrospective nature makes it susceptible to biases inherent in non-randomised studies. It limits the reliability of the data recording and is often affected by factors that are not necessarily recorded at all. A prospective approach would be able to get better data and perhaps better match patients between cohorts. Clearly, an RCT would not be possible here (I don’t think), and so this sort of data is probably as best as we can get.
• Unmeasured Confounders: Potential confounding factors (e.g., specific clinical indications for intubation) may not be accounted for due to data limitations.
• Hospital-Level Analysis: Grouping trauma centres into categories based on intubation tendency may obscure individual patient-level variations. We could do this better with a prospective approach.
• The cohort is not really like my own, with 72% of the patients in this study being penetrating trauma. We see a lot of penetrating trauma in Virchester, but probably not as much as this.

Should we change practice based on this study?

The findings suggest that intubation in the ED for patients requiring urgent haemorrhage control surgery is associated with adverse outcomes. This underscores the importance of prioritising rapid resuscitation and transport to the OR over early airway control in carefully selected patients. However, given the study’s retrospective design and potential for unmeasured confounders, these results should prompt further prospective research rather than immediate practice change. Trauma centres should consider reviewing their protocols and possibly deferring intubation when safe to do so.

For me, it means that I will continue to be very cautious about intubating (RSI) patients who are apparently bleeding to death. I think most resuscitationists would agree that the best place to induce anaesthesia for these unstable patients would be in the OR, with a great surgical team in attendance and ready to go. However, in the UK, there are very few centres that are set up to move very rapidly to theatre at all times of day and night (though it’s getting better).

There are also two excellent letters^​2,3​ that point out that patients in the ER group were sicker and were more likely to have chest trauma but without the physiological data to grade the level of chest injury (e.g. Sa02). Clearly, that sort of data would be very important in determining whether these patients are really the same, even when stratified as they are in this paper. A prospective study could certainly address those issues. Fundamentally, we lack direct data on ‘why’ individual patients were intubated, which is perhaps the most important missing piece of the puzzle.

The challenge for EM/PHEM docs is that the patient may be too sick to make it that far without intubation and those patients present a real clinical challenge (top tip – resuscitate as much as possible before you intubate and significantly reduce doses of induction agent).

Summary

This study highlights significant adverse outcomes associated with ED intubation in trauma patients requiring urgent haemorrhage control surgery. The increased mortality, longer ED time, greater blood transfusion needs, and higher complication rates suggest potential benefits of deferring intubation in favour of rapid resuscitation and transport to the OR.

However, correlation is not causation, and despite several study strengths, the retrospective design and potential confounding factors suggest that while these findings are interesting, further prospective research is needed before we can truly understand the effect.

@EMManchester

Further Reading

1. Cannon JW. Hemorrhagic shock. N Engl J Med. 2018;378(4):370-379.
2. Meizoso JP, Ray JJ, Karcutskie CA 4th, et al. Effect of time to operation on mortality for hypotensive patients with gunshot wounds to the torso: the golden 10 minutes. J Trauma Acute Care Surg. 2016;81(4):685-691.
3. Barbosa RR, Rowell SE, Fox EE, et al. Increasing time to operation is associated with decreased survival in patients with a positive FAST examination requiring emergent laparotomy. J Trauma Acute Care Surg. 2013;75(1 Suppl 1):S48-S52.
4. Byrne JP, Xiong W, Gomez D, et al. Redefining “dead on arrival”: identifying the unsalvageable patient for the purpose of performance improvement. J Trauma Acute Care Surg. 2015;79(5):850-857.
5. Shafi S, Gentilello L. Pre-hospital endotracheal intubation and positive pressure ventilation is associated with hypotension and decreased survival in hypovolemic trauma patients: an analysis of the National Trauma Data Bank. J Trauma. 2005;59(5):1140-1145.
6. Heffner AC, Swords DS, Neale MN, Jones AE. Incidence and factors associated with cardiac arrest complicating emergency airway management. Resuscitation. 2013;84(11):1500-1504.
7. Wardi G, Villar J, Nguyen T, et al. Factors and outcomes associated with inpatient cardiac arrest following emergent endotracheal intubation. Resuscitation. 2017;121:76-80.
8. De Jong A, Rolle A, Molinari N, et al. Cardiac arrest and mortality related to intubation procedure in critically ill adult patients: a multicenter cohort study. Crit Care Med. 2018;46(4):532-539.
9. Thomas AC, Campbell BT, Subacius H, et al. Time to OR for patients with abdominal gunshot wounds: a potential process measure to assess the quality of trauma care? J Trauma Acute Care Surg. 2022;92(4):708-716.