Page 57 - JSOM Summer 2022

Prehospital Traumatic Brain Injury Management

Clinical Pearls and Pathophysiology

2
1
Ricky M. Ditzel, CCP-C, SO-ATP ; Brian Y. Hwang, MD, 18D, SO-ATP *;
3
Jo H. Schmid, RN, CCNC(C), CCSNE ; Geoffrey S. F. Ling, MD, PhD 4

ABSTRACT
Traumatic brain injury (TBI) management is complex. The Secondary Survey
brain is a sensitive, high-maintenance organ that loses its abil- • 10cm scalp laceration to the right temporal region, no ex-
ity to take care of itself upon injury, and our primary mission is posed skull, no active bleeding
to achieve and maintain optimal levels of cerebral blood flow • Pupils equal bilaterally and minimally reactive to light
(CBF) from the moment of injury until recovery. The authors • Cough and gag reflexes absent
provide a case and discuss prehospital patient management, • No chest wall crepitus
including adequate oxygen saturation and blood pressure, • Right lower quadrant abdominal contusion
early recognition of TBI, frequent exams, detailed charting • Pelvis is stable
and hand-off, and fast transport to the next echelon of care. • No deformity to the extremities
• Abrasions in bilateral lower extremities
Keywords: traumatic brain injury; pathophysiology; prehospital
management; critical care Treatment Administered
The medic applies a cervical collar, ensuring it is not too tight
around the neck. She then places him on a spine board and
transports him to the nearest level 1 trauma center. En route,
Introduction
she establishes intravenous (IV) access, monitors his vitals,
Many interventions and guidelines for TBI are not supported tilts up the spine board to elevate his head above the level of
by a high level of evidence because of the complex, multifacto- the heart, maintains an end-tidal CO (EtCO ) level of 35–
2
2
rial nature of the injuries, diversity of the patient population, 40mmHg, and performs repeat neurological assessment every
and incomplete understanding of the brain and TBI patho- 5 minutes. The medic also notifies the receiving emergency
physiology. Our goal is to achieve and maintain optimal levels department that she is concerned about severe TBI and recom-
of CBF. mends emergent neurosurgery consultation.

Case Presentation Normal Physiology
The medic responds on scene to a 28-year-old male pedestrian Cerebral Blood Flow
struck by a truck traveling at approximately 40–50 mph (65– The brain is by far the most metabolically demanding organ.
80 km/hr). Upon arrival, the patient is unresponsive; he does Although the brain makes up just 2% of the total body weight,
not open his eyes, does not speak or make any sounds, and it requires 15% of the cardiac output and 20% of the total
withdraws all four extremities to pain. The medic intubates body oxygen. Normal brain function is critically dependent
1,2
the patient while maintaining manual in-line cervical spine on a continuous supply of glucose and oxygen. Because the
2
stabilization. brain is highly sensitive and vulnerable to changes in its ox-
ygen supply, it has evolved various mechanisms to maintain
Primary Survey and Initial Exam its rate of oxygen consumption, also known as cerebral meta-
Airway: Endotracheal tube bolic rate of oxygen (CMRO ). The brain must have sufficient
2
Breathing: Assisted ventilations provided by bag-valve mask cerebral blood flow (CBF) to meet its CMRO demands to
2
(BVM), equal breath sounds bilaterally function and survive. On average, CBF of a healthy adult is
3
Circulation: 1+ radial pulses bilaterally 50mL of blood for every 100g of brain tissue per minute (Fig-
Disability: Glasgow Coma Scale (GCS): 7T (eye opening none ure 1). Cerebral autoregulation is the key mechanism that the
4
(1), verbal (1T–intubated), motor localizes to pain (5) brain uses to maintain an adequate and stable CBF in the face
Vitals: Blood pressure 105/71, pulse 96 beats per minute of constantly fluctuating physiology. The brain achieves this
(bpm), temperature 97.3°F (36.2°C), respiratory rate 19/min, amazing feat by controlling the diameter of, and therefore, the
Spo 98% on 15L BVM vascular resistance of its arteries; the arteries dilate when the
2
*Correspondence to Department of Neurosurgery, Johns Hopkins School of Medicine, 600 N. Wolfe Street, Meyer 8–181, Baltimore, MD
21287; or bhwang8@jhmi.edu
1 Ricky M. Ditzel is the director of Research and Education for the Special Operations Medic Coalition (SOM+C), a post baccalaureate student at
Columbia University, and former USASOC flight medic. Brian Y. Hwang is the chief resident neurosurgeon in the Department of Neurosurgery
2
at the Johns Hopkins Hospital/School of Medicine in Baltimore, MD, and a retired US Army Special Forces Medical Sergeant. Jo H. Schmid is
3
a registered nurse in the Royal Canadian Medical Service of the Canadian Armed Forces in Ottawa, Ontario, Canada. COL (Ret) Geoffrey S.
4
F. Ling is a physician in the Division of Neurocritical Care, Departments of Neurology and Neurosurgery at the Johns Hopkins Hospital/School
of Medicine in Baltimore, MD.
55