ABCs are of paramount importance, and early intubation has been a major factor in recent improvements in trauma-related mortality
Acute Trauma Life Support (ATLS)
ATLS can be abbreviated as follows:
Airway: 1.5-3% of major trauma victims will have a cervical spine injury (thus, consider inline stabilization [Hastings RH and Marks JD. Anesth Analg 73: 471, 1991] if intubation is required).
Circulation: in particular, focus on the chest, abdomen, retroperitoneum (CT vs. angio), long bones, and drapes/street etc., the five places in which one can fatally hemorrhage.
Disability: neurologic deficit, as measured by GCS and motor neurologic exam
Exposure (followed by secondary Survey): history, diagnostic studies (ex. CBC, EKG, CT scan, FAST vs. DPL), subspecialty consultation
Induction and Intubation Outside the OR
Doses of induction agents should be reduced in proportion to the amount of hypotension present. Severely hypovolemic patients should receive no induction agents at all. 0.2 mg of scopolamine (a tertiary ammonium vagolytic) may inhibit memory formation while preserving cardiovascular stability, but can interfere with subsequent neurologic exams. Midazolam, which is a known anterograde amnestic, runs the risk of hypotension.
Many trauma patients will be hypovolemic, thus consider induction with etomidate (0.2-0.3 mg/kg) or ketamine (1-2 mg/kg). In the hemodynamically-stressed patient, ketamine, which is a direct myocardial depressant, can theoretically lead to cardiovascular collapse – in Waxman’s study of 12 critically-ill patients (5 of 12 ultimately died) given ketamine, 6 (50%) showed decreased contractility, cardiac output fell in 4 (33%), and MAP fell in 4 (33%). The worst fall in CI was from 4.99 to 3.45 (31% drop) [Waxman K et al. Anesth Analg 59: 355, 1980]. Etomidate has the unfortunate side-effect of adrenal suppression.
All patients are at risk for aspiration (delayed emptying, gastric blood, CT contrast, etc.), thus administer sodium citrate (30 cc of 0.3 M Bicitra™) if possible. Do NOT sacrifice preoxygenation for a potentially-decreased aspiration risk. The risk of aspiration is real, but Sellick’s maneuver should theoretically be able to prevent it, although it has never been proven reliable in either setting (ventilation versus true RSI). Interestingly, Sellick’s original article described his own maneuver as being useful during ventilation. [Sellick BA: Lancet 2:404, 1961]
In the past, some authors have recommended avoidance of paralysis or potent induction agents for risk for fear of an increased complication rate [Taryle DA et al. Chest 75: 541, 1979], however, this is not supported by the literature – three published studies of drug-assisted intubations (Talucci, 260 patients; Stene, 3000 patients; Rotondo, 204 patients) [Talucci RC et al. Am Surg 54: 185, 1988; Stene JK et al. Trauma Anesthesia, Baltimore: Williams & Wilkins: 64-99, 1991; Rotondo MF et al. J Trauma 34: 242, 1993] as well as unpublished data from 647 patients (adapted from Karlin A. Probl Anesth 13: 283, 2001] have shown either zero complications or a complication rate identical to that in the OR in pharmacologically-mediated induction/intubation outside the OR. Use of paralysis and adequate induction agents is therefore MORE IMPORTANT outside the OR – it increases the chances of a successful initial intubation, which is critical.
Patients with jaw and/or zygomatic arch injuries often have trismus, which complicates airway assessment and does not resolve until NMBDs are employed. Mandibular fractures and pharyngeal hemorrhage may lead to upper airway obstruction. Patients who arrive in the sitting or prone position because of airway compromise should be left that way until intubation commences.
Note that succinylcholine can be used safely if the injury/trauma occurred within 24 hours. That said, ALWAYS consider a spontaneous respiration-based induction (sevoflurane, slow-infusion of ketamine) in patients for whom a difficult airway is anticipated.
Other considerations: ENT personnel or an appropriate blade (with a 6.0 cuffed ETT) should be present. General surgery should ideally be present and have the capability of conducting an urgent tube thoracostomy, as an undiagnosed tension pneumothorax may develop after initiation of positive-pressure ventilation.
Cervical Spine Injuries
Crosby reviewed the literature on cervical spine injuries as they relate to anesthesia and came to several conclusions, including the following: “The routine use of some form of immobilization during airway maneuvers in at-risk patients is accepted as the standard of care. All airway maneuvers will result in some degree of neck movement… The available data support a conclusion that these movements are unlikely to result in neurologic injury provided that reasonable care is taken during airway interventions… There are no clinical outcome data that suggest better neurologic outcomes with any particular technique… Surveys indicate that the majority of American anesthesiologists would prefer to use a fiberoptic bronchoscope to intubate the trachea of at-risk patients and to do so with the patient awake…” [Crosby ET. Anesthesiology 104: 1293, 2006]
Thoracic injuries require upright chest films to rule out pneumothorax. Abdominal injuries will likely be evaluated via diagnostic peritoneal lavage or ultrasound, in order to rule out splenic or liver lacerations. Suspected pelvic fractures should be placed in binders and potentially sent to IR for treatment.