Prevalence and Predictors of Post-Intubation Hypotension in Prehospital Trauma Care

The Importance of Circulation in Airway Management: Preventing Postintubation Hypotension in the Trauma Bay

OBJECTIVE

To identify the modifiable and nonmodifiable risk factors associated with postintubation hypotension (PIH) among trauma patients who required endotracheal intubation (ETI) in the trauma bay.

BACKGROUND

ETI has been associated with hemodynamic instability, termed PIH, yet its risk factors in trauma patients remain underinvestigated.

METHODS

This is a prospective observational study at a level I trauma center over 4 years (2019-2022). All adult (≥18) trauma patients requiring ETI in the trauma bay were included. Blood pressure was monitored both preintubation and postintubation. Multivariable logistic regression analysis was performed to identify the modifiable and nonmodifiable factors associated with PIH.

RESULTS

Seven hundred eight patients required ETI in the trauma bay, of which, 435 (61.4%) developed PIH. The mean (SD) age was 43 (21) years and 71% were male. Median [interquartile range] arrival Glasgow Coma Scale was 7 [3-13]. Patients who developed PIH had a lower mean (SD) preintubation systolic blood pressure [118 (46) vs 138 (28), P <0.001] and higher median [interquartile range] Injury Severity Score: 27 [21-38] versus 21 [9-26], P <0.001. Multivariable regression analysis identified body mass index >25, increasing Injury Severity Score, penetrating injury, spinal cord injury, preintubation packed red blood cell requirements, and diabetes mellitus as nonmodifiable risk factors associated with increased odds of PIH. In contrast, preintubation administration of 3% hypertonic saline and vasopressors were identified as the modifiable factors significantly associated with reduced PIH.

CONCLUSIONS

More than half of the patients requiring ETI in the trauma bay developed PIH. This study identified modifiable and nonmodifiable risk factors that influence the development of PIH, which will help physicians when considering ETI upon patient arrival.

LEVEL OF EVIDENCE

Level III-Prognostic study.

Impact of resuscitation adjuncts on postintubation hypotension in patients with isolated traumatic brain injury

INTRODUCTION

Postintubation hypotension (PIH) is a risk factor of endotracheal intubation (ETI) after injury. For those with traumatic brain injury (TBI), one episode of hypotension can potentiate that injury. This study aimed to identify the resuscitation adjuncts that may decrease the incidence of PIH in this patient population.

METHODS

This is a 4-year (2019-2022) prospective observational study at a level I trauma center. Adult (18 years or older) patients with isolated TBI requiring ETI in the trauma bay were included. Blood pressures were measured 15 minutes preintubation and postintubation. Primary outcome was PIH, defined as a decrease in systolic blood pressure of ≥20% from baseline or to ≤80 mm Hg, or any decrease in mean arterial pressure to ≤60 mm Hg. Multivariable logistic regression was performed to identify the associations of preintubation vasopressor, hypertonic saline (HTS), packed red blood cell, and crystalloids on PIH incidence.

RESULTS

Of the 490 enrolled patients, 16% had mild (head AIS, ≤2), 35% had moderate (head AIS, 3-4), and 49% had severe TBI (head AIS, ≥5). The mean ± SD age was 42 ± 22 years, and 71% were male. The median ISS, head AIS, and Glasgow Coma Scale were 26 (19-38), 4 (3-5), and 6 (3-11), respectively. The mean ± SD systolic blood pressure 15 minutes preintubation and postintubation were 118 ± 46 and 106 ± 45, respectively. Before intubation, 31% received HTS; 10%, vasopressors; 20%, crystalloids; and 14%, at least 1 U of packed red blood cell (median, 2 [1-2] U). Overall, 304 patients (62%) developed PIH. On multivariable regression analysis, preintubation use of vasopressors and HTS was associated with significantly decreased odds of PIH independent of TBI severity, 0.310 (0.102-0.944, p = 0.039) and 0.393 (0.219-0.70, p = 0.002), respectively.

CONCLUSION

Nearly two thirds of isolated TBI patients developed PIH. Preintubation vasopressors and HTS are associated with a decreased incidence of PIH. Such adjuncts should be considered prior to ETI in patients with suspected TBI.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Management of Respiratory Failure in Hemorrhagic Shock

Hemorrhagic shock results in acute respiratory failure due to respiratory muscle fatigue and inadequate pulmonary blood flow. Because positive pressure ventilation can reduce venous return and cardiac output, clinicians should use the minimum possible mean airway pressure during assisted or mechanical ventilation, particularly during episodes of severe hypovolemia. Hypoperfusion also worsens dead space fraction. Therefore, clinicians should monitor capnography during mechanical ventilation and recognize that hypercapnia may be treated with fluid resuscitation rather than increasing minute ventilation.

Impact of Prehospital Exsanguinating Airway-Breathing-Circulation Resuscitation Sequence on Patients with Severe Hemorrhage

BACKGROUND

At the 2023 ATLS symposium, the priority of circulation was emphasized through the "x-airway-breathing-circulation (ABC)" sequence, where "x" stands for exsanguinating hemorrhage control. With growing evidence from military and civilian studies supporting an x-ABC approach to trauma care, a prehospital advanced resuscitative care (ARC) bundle emphasizing early transfusion was developed in our emergency medical services (EMS) system. We hypothesized that prioritization of prehospital x-ABC through ARC would reduce in-hospital mortality.

STUDY DESIGN

This was a single-year prospective analysis of patients with severe hemorrhage. These patients were combined with our institution's historic controls before prehospital blood implementation. Included were patients with systolic blood pressure (SBP) less than 90 mmHg. Excluded were patients with penetrating head trauma or prehospital cardiac arrest. Two-to-one propensity matching for x-ABC to ABC groups was conducted, and the primary outcome, in-hospital mortality, was compared between groups.

RESULTS

A total of 93 patients (x-ABC = 62, ABC = 31) met the inclusion criteria. There was no difference in patient age, sex, initial SBP, initial Glasgow Coma Score, and initial shock index between groups. When compared with the ABC group, x-ABC patients had significant improvement in vitals at emergency department admission. Overall mortality was lower in the x-ABC group (13% vs 47%, p < 0.001). Multivariable regression revealed that prehospital circulation-first prioritization was independently associated with decreased in-hospital mortality (odds ratio 0.15, 95% CI 0.04 to 0.54, p = 0.004).

CONCLUSIONS

This is the first analysis to demonstrate a prehospital survival benefit of x-ABC in this subset of patient with severe injury and hemorrhagic shock. Standardization of prehospital x-ABC management in this patient population warrants special consideration.

A Nomogram Model for Post-Intubation Hypotension in Patients with Severe Pneumonia in the Emergency Department

Background

Post-intubation hypotension (PIH) frequently occurs in the management of critically ill patients and is associated with prognosis. The study aimed to construct a prediction model for PIH events by analyzing risk factors in patients with severe pneumonia in the emergency department.

Methods

We retrospectively enrolled 572 patients with severe pneumonia diagnosed in the emergency department of West China Hospital of Sichuan University. Five hundred patients with severe pneumonia who underwent endotracheal intubation were included in the study. All patients were randomized according to 7:3 and divided into a training cohort (n=351) and a validation cohort (n=149). Risk factors for PIH were analyzed using Least Absolute Shrinkage and Selection Operator (LASSO) and multivariable logistic regression. Calibration curves, receiver operating characteristic (ROC) curve, and decision curve analysis were applied to assess the predictive model's fitness, discrimination, and clinical utility.

Results

A total of 500 patients with severe pneumonia who underwent endotracheal intubation were enrolled in this study, and PIH occurred in 234 (46.8%) of these patients. Age, heart rate, systolic blood pressure, chronic obstructive pulmonary disease, acute physiology and chronic health evaluation II score, and induction agent use were identified as significant risk factors for the occurrence of PIH. Additionally, the body mass index was the opposite of the above. The area under the ROC curve (AUC) for the model was 0.856 (95% CI, 0.818-0.894) in the training cohort and 0.849 (95% CI, 0.788-0.910) in the validation cohort. The nomogram model was validated and demonstrated good calibration and high net clinical benefit. Finally, to facilitate application by clinicians, an online server has been set up which can be accessed free of charge via the website https://chinahospitals.shinyapps.io/DynNomapp/.

Conclusion

The nomogram is used for individualized prediction of patients with severe pneumonia prior to intubation and is simple to perform with high clinical value.

A CIRCULATION-FIRST APPROACH FOR RESUSCITATION OF TRAUMA PATIENTS WITH HEMORRHAGIC SHOCK

ABSTRACT

The original guidelines of cardiopulmonary resuscitation focused on the establishment of an airway and rescue breathing before restoration of circulation through cardiopulmonary resuscitation. As a result, the airway-breathing-circulation approach became the central guiding principle of resuscitation. Despite new guidelines by the American Heart Association for a circulation-first approach, Advanced Trauma Life Support guidelines continue to advocate for the airway-breathing-circulation sequence. Although definitive airway management is often necessary for severely injured patients, endotracheal intubation (ETI) before resuscitation in patients with hemorrhagic shock may worsen hypotension and precipitate cardiac arrest. In severely injured patients, a paradigm shift should be considered, which prioritizes restoration of circulation before ETI and positive pressure ventilation while maintaining a focus on basic airway assessment and noninvasive airway interventions. For this patient population, the most reasonable current strategy may be to target a simultaneous resuscitation approach, with immediate efforts to control hemorrhage and provide basic airway interventions while prioritizing volume resuscitation with blood products and deferring ETI until adequate systemic perfusion has been attained. We believe that a circulation-first sequence will improve both survival and neurologic outcomes for a traumatically injured patient and will continue to advocate this approach, as additional clinical evidence is generated to inform how to best tailor circulation-first resuscitation for varied injury patterns and patient populations.

Optimizing Physiology During Prehospital Airway Management: An NAEMSP Position Statement and Resource Document

Airway management is a critical component of resuscitation but also carries the potential to disrupt perfusion, oxygenation, and ventilation as a consequence of airway insertion efforts, the use of medications, and the conversion to positive-pressure ventilation. NAEMSP recommends:Airway management should be approached as an organized system of care, incorporating principles of teamwork and operational awareness.EMS clinicians should prevent or correct hypoxemia and hypotension prior to advanced airway insertion attempts.Continuous physiological monitoring must be used during airway management to guide the timing of, limit the duration of, and inform decision making during advanced airway insertion attempts.Initial and ongoing confirmation of advanced airway placement must be performed using waveform capnography. Airway devices must be secured using a reliable method.Perfusion, oxygenation, and ventilation should be optimized before, during, and after advanced airway insertion.To mitigate aspiration after advanced airway insertion, EMS clinicians should consider placing a patient in a semi-upright position.When appropriate, patients undergoing advanced airway placement should receive suitable pharmacologic anxiolysis, amnesia, and analgesia. In select cases, the use of neuromuscular blocking agents may be appropriate.

When Minutes Matter: Rapid Infusion in Emergency Care

Purpose of Review

This review provides historical context and an update on recent advancements in volume resuscitation for circulatory shock. Emergency department providers who manage critically ill patients with undifferentiated shock will benefit from the insights of early pioneers and an overview of newer techniques which can be used to optimize resuscitation in the first minutes of care.

Recent Findings

Rapid infusion of fluids and blood products can be a life-saving intervention in the management of circulatory and hemorrhagic shock. Recent controversy over the role of fluid resuscitation in sepsis and trauma management has obscured the importance of early and rapid infusion of sufficient volume to restore circulation and improve organ perfusion. Evidence from high-quality studies demonstrates that rapid and early resuscitation improves patient outcomes.

Summary

Current practice standards, guidelines, and available literature support the rapid reversal of shock as a key priority in the treatment of hypotension from traumatic and non-traumatic conditions. An improved understanding of the physiologic rationale of rapid infusion and the timing, volume, and methods of fluid delivery will help clinicians improve care for critically ill patients presenting with shock.

Clinical Case

A 23-year-old male presents to the emergency department (ED) after striking a tree while riding an all-terrain vehicle. On arrival at the scene, first responders found an unconscious patient with an open skull fracture and a Glasgow coma scale score of 3. Bag-valve-mask (BVM) ventilation was initiated, and a semi-rigid cervical collar was placed prior to transport to your ED for stabilization while awaiting air transport to the nearest trauma center. You are the attending emergency medicine physician at a community ED staffed by two attending physicians, two physicians assistants, and six nurses covering 22 beds. On ED arrival, the patient has no spontaneous respiratory effort, and vital signs are as follows: pulse of 140 bpm, blood pressure of 65/30 mmHg, and oxygen saturation 85% while receiving BVM ventilation with 100% oxygen. He is bleeding profusely through a gauze dressing applied to the exposed dura. The prehospital team was unable to establish intravenous access. What are the management priorities for this patient in shock, and how should his hypotension best be addressed?