Operative Management

Evaluation of the multiple trauma patient emergently transported to the OR involves reviewing pre-existing conditions, vital signs, oxygenation, and preoperative fluid replacement, and confirmation of correct position and patency of a previously inserted endotracheal tube.

Monitoring
1. Hemodynamic Monitoring. Direct intra-arterial pressure monitoring, which permits beat-to-beat data acquisition and sampling for measurement of blood gases, should be in place before surgery.
  1. Delaying emergent surgery to place a central venous line is rarely indicated unless a large-bore catheter is needed for volume resuscitation.
  2. TEE provides valuable diagnostic information (blunt cardiac injury. assessment of cardiac function, acute ischemia).
2. Urine output is routinely monitored as an indicator of organ perfusion, hemolysis, skeletal muscle destruction, and urinary tract integrity after trauma. (Reliability for monitoring perfusion is decreased by prolonged shock prior to surgery and osmotic diuresis caused by administration of mannitol or radiopaque dye.)
  1. Dark, cola-colored urine in the trauma patient suggests either hemoglobinuria resulting from incompatible blood transfusion or myoglobinuria caused by massive skeletal muscle destruction after blunt or electrical trauma.
  2. Red-colored urine usually is caused by hematuria, which, in the traumatized patient, suggests urinary tract injury.
3. Oxygenation. Finger or earlobe pulse oximeters are more affected by decreased perfusion than forehead oximeters (senses the pulsation of the supraorbital artery, a branch of the carotid artery, which is presumably less affected by shock or hypothermia). Multiwavelength pulse co-oximeters can measure methemoglobin and COHb (useful in acute burn injury management).
4. Organ Perfusion and Oxygen Utilization
  1. Unrecognized hypoperfusion may lead to splanchnic ischemia with resulting acidosis in the intestinal wall, permitting the passage of luminal microorganisms into the circulation and release of inflammatory mediators, causing sepsis and multiorgan failure.
  2. Base deficit and blood lactate level are acceptable markers of organ hypoperfusion in the apparently resuscitated patient and may be used intraoperatively to set the optimal end points of resuscitation.
5. Coagulation
  1. Conventional blood coagulation monitoring includes a baseline and subsequent serial measurements of prothrombin time, international normalized ratio, activated partial thromboplastin time, platelet count, blood fibrinogen level, and fibrin degradation products.
  2. Thrombelastography and rotation thromboelastometry are point-of-care devices that provide a relatively rapid, comprehensive, and quantitative graphic evaluation of clotting function (Fig. 52-4: Thromboelastogram).
Anesthetic and adjunct drugs for general anesthesia need to be tailored to five major clinical conditions (airway compromise, hypovolemia, head or open-eye injuries, cardiac injury, burns).
1. Airway Compromise
  1. Anesthetics and muscle relaxants should be avoided before the airway is secured if there is significant airway obstruction or if there is doubt as to whether the patient's trachea can be intubated because of anatomic limitations.
  2. If time permits, lateral neck radiographs, CT scanning, and endoscopy can be used to define better the problems.
  3. Topical anesthesia with mild sedation can be used to secure the airway with a conventional blade, video laryngoscope, or fiberoptic bronchoscopy.
2. Hypovolemia
  1. Anesthetic agents not only have direct cardiovascular depressant effects but also inhibit compensatory hemodynamic mechanisms such as central catecholamine output and baroreflex (neuroregulatory) mechanisms, which maintain systemic pressure in hypovolemia.
  2. Hemorrhage and hypovolemia lead to a higher than normal anesthetic blood concentrations following a given dose of IV agents (increased sensitivity of the brain to anesthetics, preferential distribution of the cardiac output to the brain and the heart).
  3. Two important principles in the use of anesthetic agents are accurate estimation of the degree of hypovolemia and reduction of doses accordingly.
3. Head and Open-Eye Injuries
  1. Deep anesthesia and adequate muscle relaxation is important during airway management of patients with head or open-eye injuries.
  2. Anesthetic agents selected for management of brain injury should produce the least increase in ICP, the least decrease in mean arterial pressure, and the greatest reduction in cerebral metabolic rate (CMRO₂).
  3. Hypotension caused by anesthetics or other factors contributes to the development or progression of cerebral ischemia.
4. Cardiac Injury
  1. If there is pericardial tamponade, preload and myocardial contractility must be maintained. If general anesthesia is required to relieve the tamponade, induction should be delayed until the patient is prepared and draped.
  2. In chronic pericardial effusion, ketamine supports the cardiac index better than other IV agents. In acute pericardial tamponade, even minor insults can bring cardiac activity to a halt. Ketamine thus remains the agent of choice.
5. Burns
  1. A hypermetabolic state characterized by tachycardia, tachypnea, catecholamine surge, increased O₂ consumption, and augmented catabolism follows the initial few hours of a burn and continues into the convalescent phase, necessitating increased oxygen, ventilation, and nutrition.
  2. Early extensive and repeated escharotomies with coverage by skin grafts attenuate the postburn hypermetabolic response, decrease insulin resistance, decrease fluid loss, and improve survival.
  3. Anesthetic management of escharotomies presents several difficulties (access for ECG, pulse oximeter, neuromuscular function, and noninvasive blood pressure monitoring).
  4. Hyperthermia occurs, but hypothermia is more likely in the OR.
  5. For serial wound debridement, ketamine in intermittent doses or neuraxial or peripheral nerve blocks via an indwelling catheter should be used.

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