Initial Resuscitation, Prehospital Care, and Emergency Room Care in Traumatic Brain Injury

Published on 13/03/2015 by admin

Last modified 13/03/2015

Print this page

This article have been viewed 38460 times

CHAPTER 333 Initial Resuscitation, Prehospital Care, and Emergency Room Care in Traumatic Brain Injury

Arun Jacob, M. Sean Grady, Gregory G. Heuer

A critical objective of management of traumatic brain injury (TBI) is to prevent secondary injury. The two most common causes of secondary injury are intracranial mechanisms (e.g., hematoma and elevated intracranial pressure [ICP]) and systemic mechanisms (e.g., shock and hypoxemia). Efficient management by trauma and neurosurgery teams prevents secondary brain damage through adequate oxygenation and maintenance of adequate cerebral perfusion pressure. During the past decade, there has been remarkable improvement in prehospital evaluation and treatment, which significantly affects patient outcome. Universal implementation of advanced trauma life support protocols and Glasgow Coma Scale (GCS) has helped in standardizing trauma care. The latter has become the standard scoring system for assessing the level of consciousness and helps prognosticate head injury outcome.¹

Prehospital Management

Rapid removal of the accident victim to a trauma care facility is critical to improve the chances of survival. Guidelines for prehospital management outlined by the Brain Trauma Foundation have been useful in this respect (Table 333-1). Paramedical personnel must work with the police and fire service to secure the scene and remove the patient safely without causing injury either to the casualty or other personnel at the scene.² Wilmink and coworkers, following a review of 737 motor vehicle crashes, recommended a target of less than 30 minutes for the extrication of entrapped victims. ³ However, they emphasized that uncontrolled release is indicated only if there is an immediate threat to the victim’s life. Although expertise in safely extricating patients is crucial, there is considerable evidence that the experience of rescuers, medical training, and the timeliness of transport to an appropriate hospital also influence patient outcomes.

TABLE 333-1 Guidelines for Prehospital Management of Traumatic Brain Injury

I Assessment: oxygenation and blood pressure

Monitor oxygen saturation and blood pressure continuously

Avoid hypoxemia(<90% O₂ saturation) and hypotension (<90 mm Hg systolic blood pressure)

II Assessment: Glasgow Coma Scale (GCS) score

Use as reliable indicator of severity of traumatic brain injury and also for prognosis

Obtain after securing airway, breathing, and circulation

Obtain before administering sedatives or paralytics

Obtain using trained personnel by interacting with the patient

III Assessment: pupil examination

Assess in the field for use in diagnosis and prognosis

Note evidence of orbital trauma

Assess after resuscitation and stabilization

Record bilateral pupillary size and reflex

IV Treatment: airway, ventilation, and oxygenation

Establish airway in patients who have severe brain injury, inability to maintain airway, or hypoxemia with supplemental oxygen

Avoid hypoxemia (SpO₂ < 90%)

Monitor blood pressure, oxygenation, and end-tidal carbon dioxide (ETCO₂) while implementing endotracheal intubation protocols

Confirm position of endotracheal tube by auscultation and ETCO₂ determination

Avoid hyperventilation (ETCO₂ > 35 mm Hg) unless patient shows evidence of cerebral herniation

In ground transportation in urban environment, routine use of paralytics is not recommended for intubating adult patients who are spontaneously breathing and maintaining SpO₂ above 90%

V Treatment: fluid resuscitation

Treat hypotensive patients with isotonic fluids

VI Treatment: cerebral herniation

Avoid mild or prophylactic hyperventilation (PaCO₂ < 35 mm Hg)

Assess patient frequently for clinical signs of cerebral herniation, which include dilated unreactive pupils, asymmetric pupils, extensor posturing/no response or progressive neurological deterioration—decrease in Glasgow Coma Scale score by more than 2 points from prior best score

In patients who are normoventilated, well oxygenated, and normotensive, hyperventilation can be used as temporizing measure to keep ETCO₂ between 30 and 35 mm Hg

Administer hyperventilation as 20 breaths/min in adult, 25 in child, and 30 in infant

The importance of prehospital services has been underlined by a prospective study comparing the overall mortality rate, in severe and moderate TBI patients, in two different environments: New Delhi, India, and Charlottesville, Virginia.⁴ The overall mortality rate was 11% in New Delhi versus 7.2% in Charlottesville. The mortality rates for victims with severe injuries (GCS motor score of 1 to 4) and those with mild injuries (GCS motor score of 6) were similar at both centers. Those patients with moderate injuries (GCS motor score of 5) had a mortality rate of 12.5% in New Delhi, compared with 4.8% in Charlottesville. This dramatic difference is attributed to the differences in prehospital emergency services. In New Delhi, 2.7% of victims received first aid administered by paramedical personnel or police before arriving at the hospital, whereas in Charlottesville, paramedics attended to 84.3% of victims and transported them by ambulance. The differences in transportation were also reflected in the percentage of patients admitted to the hospital within 1 hour of being injured: 6.9% in New Delhi, compared with 50.2% in Charlottesville. In regions where air transport is a feasible means of decreasing transport time to the trauma center, reductions in predicted mortality rates as high as 52% have been reported.⁵

Introduction of helicopter emergency medical services (HEMS) has revolutionized trauma care and has been shown to improve survival outcome. Proper identification of critically injured patients who need rapid transport is important for optimal use of this expensive mode of transport.⁶ The concept of physician-staffed HEMS was introduced to provide more definitive care to blunt trauma victims without prolonging the on-scene time.⁷^–⁹ Initial studies showed up to a 35% decrease in mortality rate among patients treated by a nurse-physician team.⁸ Recent studies, however, have not shown any benefit in outcome compared with nonphysician-staffed HEMS.⁹

All patients with a GCS score equal to or less than 8 must be intubated and given controlled ventilation with continuous monitoring of oxygenation by pulse oximetry. Preventing hypoxemia and hypercapnia is a crucial step in prehospital management. Treatment is similar in head injury patients with significant deterioration of level of consciousness, seizures, respiratory distress, or severe facial and thoracoabdominal injuries. The priority for emergency medical service (EMS) is to immobilize the spine and achieve safe airway for use of rapid sequence intubation (RSI). A study at Harborview Medical Center showed a decrease in mortality among TBI patients after early prehospital intubation, although the rate of severe hypercapnia was 18%. Patients with severe hypercapnia had higher Injury Severity Scores and were more likely hypotensive, hypoxic, and acidotic.^10,¹¹ The San Diego Paramedics RSI Trial documented an increase in mortality after paramedic RSI, with hyperventilation and aspiration pneumonia identified as the major risk factors.¹² Adequate training, regular experience, and close monitoring of a limited group of providers helps to maximize their exposure and experience with RSI.¹³

It is difficult to attribute improved outcomes in patients treated in the prehospital setting to a specific intervention; however, prevention of hypoxia and hypotension appears to be vital.^14,¹⁵ The incidence of hypoxia or hypotension on arrival at the hospital has been shown to be decreased from 30% to 12% by simple improvements in prehospital airway management, including an increased use of intubation and mechanical ventilation.^16,¹⁷ Patients with hypotension after severe TBI have twice the mortality rate of normotensive patients.¹⁸ Therefore, aggressive resuscitation with intravenous fluids is recommended in current guidelines for the management of patients with severe TBI.¹⁹ Treatment of increased ICP in patients with TBI is also likely to improve outcomes.²⁰ A double-blind randomized controlled trial has shown the efficacy of hypertonic saline as resuscitation fluid in TBI patients in the prehospital setting without affecting the long-term neurological outcome.²¹

Adequate resources must include paramedics or physicians in the emergency response group who are capable of intubating patients in the prehospital setting. When a GCS score is determined in the prehospital setting, it can be useful as a comparison with the score in the emergency department. Winkler and coworkers demonstrated that patients whose GCS did not improve between the prehospital and initial hospital evaluation had worse outcomes.²²

General Trauma Resuscitation and the Trauma Team

The American College of Surgeons (ACS) Committee on Trauma has outlined guidelines regarding responsibilities of the trauma response team.²³ The composition and organization of the trauma response team vary with the resources available, the volume of trauma cases treated at each medical center, and local government guidelines. The goal of this group is to receive patients in the emergency room, treat the primary injuries, and prevent additional injury. A center with few trauma cases may assess and resuscitate patients in a general “code room,“ whereas larger centers use a designated trauma bay within the emergency department. Immediate access to a ventilator, operative instruments, unmatched O-negative packed red blood cells, and plain radiographs are necessary. Prompt availability of a computed tomography (CT) scanner, preferably within the emergency department, is essential.

Trauma centers, particularly level I centers, play an important role in the management of head injury patients. A multi-institutional, prospective study that involved the examination of costs and outcomes of care received by more than 5000 adult trauma patients 18 to 84 years of age treated at 69 hospitals located in 12 states concluded that the overall risk for death is significantly lower when care is provided in a trauma center rather than in a nontrauma center.²⁴ Severely injured patients with an Injury Severity Score higher than 15 treated in ACS level I trauma centers have considerably better survival outcomes than those treated in ACS level II centers.²⁵

The trauma population can have a higher incidence of blood-borne infections compared with the general emergency department population.²⁶ Tardiff and colleagues studied patients who died from trauma in New York City.²⁷ Overall, 7.2% were HIV positive, and 20.8% of patients 35 to 44 years old were HIV positive. Kelen and associates tested all patients visiting an inner-city emergency department in Baltimore and found that 24% were infected with at least one of the following: HIV, hepatitis B virus, or hepatitis C virus.²⁸ Because of this increased risk, all participants in the trauma bay must strictly follow universal precautions. These include a fluid-impervious gown, mask, eye shield, head covering, and gloves.²⁹

The trauma team leader assigns portions of the evaluation to specific individuals. These assignments are best done in advance; if, however, they are done during the evaluation, they must be clear and specific, to minimize confusion. Aspects of the initial assessment that may be given to other members of the team include airway management, intravenous access, or the primary survey. Nursing support is vital to assist in each step of the process. One individual should also be responsible for recording rapidly received data onto the trauma flow sheet. Additional support may be needed from a social worker to communicate with family members, a security guard to minimize the presence of unnecessary people in the trauma area, a secretary to call consultants, and a messenger service to assist with patient or resource transport.