After ensuring scene safety, the immediate management of the patient with traumatic brain injury (TBI) in a field setting should focus on stabilizing and maintaining oxygenation and blood pressure. All head-injured patients have potential cervical injury and should be immobilized. A fundamental premise in prehospital care is to anticipate and prepare for eventualities such as vomiting, seizures, and aberrations of blood pressure or oxygenation.
15.2.1 Should Tracheal Intubation Be Performed in the Field for This Patient?
In this patient, ensuring oxygenation via a patent airway is of paramount importance. Indications for a field intubation include inadequate ventilation or oxygenation despite supplemental oxygen administration or the inability of the patient to protect the airway. A relative indication for intubation is the risk of losing the airway during transport. Transport time and type of transport, that is, ground versus aeromedical, must be taken into consideration. Studies of the outcome of prehospital intubations have yielded conflicting results1,2,3-5 and, as discussed in Chapter 14, prehospital airway management protocols are currently being further investigated. In the case presented, the patient was maintaining oxygenation and ventilation. His clinical course could not be certain, and it was reasonable for the field team to consider tracheal intubation. However, the patient had clenched teeth and was predicted to pose a difficult laryngoscopic intubation based on his short neck and cervical spine immobilization. A decision to intubate would involve the use of a rapid-sequence intubation (RSI) protocol; considering the short transport time, RSI was not indicated.
15.2.2 What Additional Considerations Are Imposed by Field Conditions?
Several other priorities in clinical care must be addressed by the field team after initial patient stabilization.
Hypotension is a critical factor associated with an increased morbidity and mortality in patients with head injuries.6,7 Blood pressure in the field should be monitored closely with the goal of avoiding hypotension (systolic BP <90 mm Hg in adults); if present, it should be corrected immediately. This patient presented with a field BP of 90/60 mm Hg. As hypotension is strongly associated with poor outcomes in TBI patients, fluid resuscitation becomes a priority. However, the field team must weigh the benefit of delaying transport from the field to secure an IV with the risk of delayed transport to a trauma center. Ideally, IV access should be attempted as the patient is expeditiously transported to the trauma center. It should be emphasized that isolated brain injury rarely accounts for hypotension in trauma patients with multisystem injury;8 rather, if present, hemorrhage must always be suspected.
126.96.36.199 Neurologic Disability: ICP and C-Spine
ICP: The GCS of seven, 10 minutes after the injury, is not predictive of the patient's clinical course or prognosis (other than the increased likelihood of C-spine injury). The patient did not have unequivocal evidence of increased intracranial pressure (ICP) since the pupils were equal and reactive and the motor response was decorticate, not decerebrate. As such there was no indication for paramedics to provide any intervention for managing elevated ICP with modalities such as intubation/hyperventilation, mannitol, or hypertonic saline.9
A potential pitfall in the management of the TBI patient is to assume that trauma is entirely responsible for altered mental status. Consideration must be given to the reversible causes of altered mental status, that is, hypoglycemia and drug toxicity, in addition to hypoxemia and hypotension.
C-spine immobilization: All patients with blunt trauma to the torso or neurological dysfunction should be suspected of having spinal cord injury until proven otherwise. Although neurologic impairment is fully manifest at the time of injury in most patients with vertebral injury,10 the implications of an unidentified spine injury are such that routine use of immobilization devices is indicated. Secondary neurological injuries are reported to occur in 10% to 30% of patients with delayed diagnosis, who are not immobilized at time of entry into care11,12 and in 2% to 10% of those who are immobilized.13 Three recent studies suggest that the probability of associated C-spine injury is at least tripled with GCS scores of 8 or less.14-16 Studies of techniques for optimal cervical immobilization have supported the use of a rigid cervical collar that incorporates the upper thorax, stabilization blocks on either side of the head, and a long spine board for transport.17,18 Spinal immobilization is not without consequence in that patients are at risk of aspirating if they seize, vomit, or lose protective airway mechanisms. In addition, collars have been consistently demonstrated to increase ICP and may worsen intracranial pressure dynamics in patients with head injury,19-23 probably by interference with cerebral venous drainage.24 With the history of TBI and GCS of 7, the presented patient was at significant risk of cervical spine trauma and required full cervical spine immobilization.
Patients with severe head injuries can experience episodes of agitation and combativeness, both of which tend to increase intracranial pressure, and can pose safety risks to both the patient and the field paramedic crew. Sedatives, such as benzodiazepines and opioid analgesics, are typically employed but, if given, the GCS score should first be determined, and the status of oxygenation and ventilation closely monitored after administration.
188.8.131.52 Transport Decisions
A priority in the early management of patients with moderate or severe brain injuries is transportation to the closest facility providing immediate access to neuroimaging and neurosurgical services. Patients with severe TBI transported to trauma centers without the availability of prompt neurosurgical care are at risk of a poor outcome.7 Acute subdural hematomas in patients with severe TBI are associated with a 90% mortality if evacuated more than 4 hours after injury, but only 30% mortality if evacuated earlier.25,26 Consequently, it is recommended that field emergency medical services (EMS) systems operate under strict ground and aeromedical trauma transport protocols. Commonly accepted criteria for transport of head-injured patients to a trauma center include severity of injury, a respiratory rate less than 10, systolic blood pressure less than 90 mm Hg, and a GCS score less than 12.