Pre-Induction

1. Hypothermia is one of the arms of the lethal triad of coagulopathy, acidosis, and hypothermia.5 As such, it is important to warm the OR to greater than 30C and have a warmed intravenous (IV) line, forced air warmer, and rapid infuser with warming capability immediately available. Standard checks (e.g., anesthesia machine check, airway equipment is in proper working order) assure that vital equipment is ready for immediate use.
2. Establishment of a massive transfusion protocol and effective communication with the blood bank is essential and can improve survival.6 The Damage Control Resuscitation CPG7 defines the massive transfusion protocol for the combat theater. At all roles of care, awareness of the individual military medical facilities (MTFs) on-hand resources (including walking blood bank) and applicable protocols are key considerations.
3. The presence of anesthesia in the trauma bay is necessary for smooth transition of care to the OR and offers the opportunity to assist with invasive procedures. Identification of team roles prior to patient arrival facilitates effective transfer from the delivering team.

INDUCTION OF ANESTHESIA

1. Induction of anesthesia in the exsanguinating patient can be challenging. Ongoing volume resuscitation to prevent occurrence of cardiac arrest in the peri-anesthetic period is critical.

2. After a patient is identified for surgery, verification of functioning vascular access (either intravenous or intraosseous) and placement of monitoring devices (e.g., oxygen saturation, blood pressure, and electrocardiogram) must occur quickly.

3. Do not delay induction of the patient in extremis in order to place the central venous access or invasive monitoring. Placing monitors at the same time as the surgical prep and drape can save time in a crisis. A wide draping procedure with “arms out” ensures adequate surgical exposure, while affording access to the arms as needed after the start of surgery. Pre-oxygenation with four full vital capacity breaths can “de-nitrogenate” the end alveoli sufficiently to optimize oxygenation prior to rapid sequence induction. In the obtunded patient, it may not be possible to achieve four vital capacity breaths prior to induction, and one must proceed with induction relying upon apneic oxygenation.

4. There are a variety of sedative hypnotics available for induction of anesthesia. Standard induction dosages should be reduced and titrated to balance the induction of anesthesia with hemodynamic changes. Ketamine (1 mg/kg) will not decrease the systemic vascular resistance to the same extent as other sedative hypnotics. While Propofol is a standard induction agent, it can decrease the systemic vascular resistance significantly. It is prudent to use reduced doses of Propofol (0.5-1 mg/kg) in hypotensive patients. Ongoing volume resuscitation is vital to prevent vascular collapse.

5. Neuromuscular relaxation sufficient to facilitate endotracheal intubation can be achieved in approximately 45 seconds with succinylcholine in a standard rapid sequence induction dose (1mg/kg). Rocuronium is a non-depolarizing neuromuscular relaxant useful in cases where succinylcholine may be contraindicated(e.g., burns, spinal cord injury, hyperkalemia). An increased dose of Rocuronium (1-1.2 mg/kg) can produce intubating conditions similar to succinylcholine in approximately 60 seconds.

6. Prompt endotracheal intubation of the trachea following induction mitigates the risk of aspiration. Rapid sequence induction (RSI) with direct laryngoscopy is a safe and effective method to secure the airway of the trauma patient.8, 9 The efficacy of in-line stabilization during RSI is somewhat controversial; however, it remains prudent to minimize the manipulation of the cervical spine to the extent possible during laryngoscopy. Regardless, it is re-assuring to know that spinal cord injury following direct laryngoscopy rarely causes or worsens cervical spine injury.10

7. A variety of airway adjuncts are available to the laryngoscopist. The gum elastic bougie can be helpful in securing a challenging airway and is a low-cost, effective airway adjunct.11 Video laryngoscopy can provide an improved view of the vocal cords during intubation and has recently been shown to improve first pass success rate, especially for less experienced providers. Therefore, video laryngoscopes are preferred over direct laryngoscopes when available.12 It remains prudent to have a limited number of immediately available airway adjuncts with which one is familiar, rather than a larger selection of less familiar equipment.13 An alternate plan, including equipment for surgical airway management, must also be immediately available. (See Airway Management of Traumatic Injuries CPG14)

8. After intubation of the trachea and verification of end tidal carbon dioxide, communication with the surgeon ensures that the operation proceeds in a timely fashion. Placement of an orogastric tube at this point may potentially decrease the risk of aspiration.