March brought the first edition of our Air Care flight physician orientation case series with the goal of preparing our first year residents for their roles as flight physicians. This is a monthly series that will continue through the end of the academic year in July. First year residents discuss the case and its associated questions on our internal asynchronous learning forum, Slack. We will then post a summary of the case and discussion points. Below is case number one, and the corresponding learning points.
You and your flight nurse at Air Care 2 are dispatched at 14:05 to a "MVC - Entrapped". You get more information en route from the Fire/EMS Liaison Officer reporting that the patient has just been extricated after about 20 minutes entrapped.
You land and enter the ambulance to receive this report from medics:
Your vital signs and physical exam are as noted:
VS: HR 115 BP 80/40 RR 28 SpO2 89% on NRB
General: male in acute distress, backboard and collar in place with multiple abrasions and contusions
CV: tachycardic, regular
Pulm: Decreased breath sounds on the right, crepitus over right chest wall
Abdomen: +seatbelt sign, tender to palpation diffusely
MSK: deformity to right femur, no other obvious deformities or instability
Neuro: moaning incomprehensibly, opens eyes to painful stimuli, withdraws to pain
What steps comprise your initial assessment and why?
What are your treatment priorities and who will perform each of these?
Does this patient require intubation? If so, why?
When and how would you perform RSI on this patient?
Does this patient need blood products? If so, to what end point? Any other medication considerations?
In response to these questions, a robust discussion with many excellent points ensued among our rising flight physicians. Most suggest an initial assessment plan that was a variation of the ABCs with priority given to initial hemorrhage control. Many specifically cited the military's excellent "MARCH" algorithm where "M" focuses on addressing massive hemorrhage up front. This might entail a tourniquet, pelvic binder, or simply aggressive direct pressure. In this case, several physicians suggested the use of a pelvic binder despite the conspicuous absence of reported pelvic instability. Pelvic instability is a poorly sensitive finding and a pelvic binder has trivial risks when placed correctly, especially compared to the risk of exsanguination from an untreated open book pelvic fracture.
Treatment priorities were in general resuscitation followed by intubation. Most acknowledged the hemodynamic misadventures that would occur with front-loaded intubation. As part of this initial resuscitation, many were concerned that the constellation of decreased breath sounds, hypoxia, and hypotension represented a tension pneumothorax and were quick to perform needle thoracostomy with low threshold for finger thoracostomy if no improvement. Most identified a few indications for volume resuscitation, not the least of which was the patient's shock index (HR/SBP). In this case it approximated 1.4, placing him at a high likelihood to require the massive transfusion protocol. In a likely bleeding patient, the best volume expander are blood products. Based on the favorable PROPPR trial, a 1:1 ratio of pRBCs and plasma was suggested. On Air Care, which carries both of these, plasma is usually started first. A few physicians wanted to give TXA empirically to further address hemorrhage, which is reasonable when a thromboelastogram is unavailable to assess for systemic lysis. Physicians identified myriad ways to choreograph the logistics of these procedures between them and the flight nurse.
Most did feel the patient warranted intubation for myriad reasons: mental status, acute hypoxic respiratory failure, and anticipated clinical course (transport, possible CT, possible OR, etc.). Following an initial aggressive resuscitation and preoxygenation/denitrogenation on the NRB mask, the strong consensus for induction was ketamine. One astute physician pointed out that ketamine is a great agent but can still cause hypotension at full induction dose in a shocked patient (Miller, Mathew et al 2016). Knowing that at full dose, even our beloved ketamine can cause hemodynamic collapse (likely by lysis of sympathetic tone), a reduced dose of 0.5-1 mg/kg ketamine might be in order for this patient whose sympathetic drive is the one thing keeping him alive. This should reliably induce a state of amnesia, loss of awareness, and/or dissociation without entirely blunting his adrenergic drive. Either paralytic agent would be safe in this patient, but succinylcholine would assure a reliable neurologic exam at the receiving facility should neurosurgical intervention be warranted.
Finally, Dr. Hinckley raised the shrewd reminder to check a blood sugar, highlighting the unfortunate scenario of intubating a patient whose altered mental status was largely or entirely resultant from hypoglycemia.
In sum, the case was full of great learning points and team discussion, reminding us of the perils and nuances in caring for a sick polytrauma patient in hemorrhagic shock. Stay tuned for next month's case and subsequent discussion!