What prehospital management is indicated for bradycardia (abnormally slow heart rate) in the presence of suspected elevated Intracranial Pressure (ICP) and Cushing's triad (a sign of increased ICP characterized by bradycardia, hypertension, and irregular breathing)?

From the Guidelines

For bradycardia with suspected elevated intracranial pressure (ICP) and Cushing's triad, paramedics should prioritize airway management and avoid treating the bradycardia with atropine, as recommended by the most recent guidelines 1.

Prehospital Management

The primary goal in managing bradycardia with suspected elevated ICP and Cushing's triad is to maintain cerebral perfusion pressure without exacerbating the increased ICP.

• Secure the airway through endotracheal intubation while maintaining cervical spine precautions if trauma is suspected.
• Hyperventilate the patient to a target EtCO2 of 30-35 mmHg using 100% oxygen, as this temporarily reduces ICP by causing cerebral vasoconstriction 1.
• Position the patient with the head elevated at 30 degrees if no spinal injury is suspected to promote venous drainage.

Avoiding Atropine

Atropine administration is generally avoided in this context because the bradycardia is a compensatory mechanism in Cushing's triad, representing the body's attempt to maintain cerebral perfusion 1.

Alternative Management

Instead of atropine, focus on rapid transport to a facility with neurosurgical capabilities. If hypotension develops, use small boluses of vasopressors like norepinephrine (2-4 mcg/min) or phenylephrine (50-100 mcg boluses) to maintain cerebral perfusion pressure without excessively raising ICP.

Monitoring

Monitor neurological status continuously using the Glasgow Coma Scale and pupillary responses during transport, as deterioration may indicate herniation requiring immediate intervention 1.

From the FDA Drug Label

1 INDICATIONS & USAGE Atropine Sulfate Injection, USP, is indicated for temporary blockade of severe or life threatening muscarinic effects, e.g., as an antisialagogue, an antivagal agent, an antidote for organophosphorus or muscarinic mushroom poisoning, and to treat bradyasystolic cardiac arrest.

12 CLINICAL PHARMACOLOGY ... Atropine-induced parasympatholic inhibition may be preceded by a transient phase of stimulation, especially on the heart where small doses first slow the rate before characteristic tachycardia develops due to paralysis of vagal control ... Adequate doses of atropine abolish various types of reflex vagal cardiac slowing or asystole

The prehospital management indicated for bradycardia in the presence of suspected elevated ICP and Cushing's triad is atropine administration. Atropine can counteract reflex vagal cardiac slowing, which is a component of Cushing's triad. However, it is essential to note that atropine's effect on heart rate may be preceded by a transient phase of stimulation, and its use should be carefully considered in the context of potential increased ICP. 2 2

From the Research

Prehospital Management of Bradycardia with Suspected Elevated ICP and Cushing's Triad

• The management of bradycardia in the presence of suspected elevated Intracranial Pressure (ICP) and Cushing's triad is critical and requires careful consideration of the underlying pathophysiology 3.
• In patients with suspected elevated ICP, the use of hyperosmolar agents such as mannitol and hypertonic saline may be beneficial in reducing ICP 4.
• However, the management of bradycardia in this context is more complex, and the use of atropine may be considered in patients with hemodynamically unstable bradycardia 5.
• Transcutaneous cardiac pacing (TCP) may also be considered in patients with symptomatic bradycardia, particularly those with a palpable pulse upon paramedic arrival 6.
• The American Heart Association (AHA) Pediatric Advanced Life Support (PALS) guidelines recommend interventions such as oxygen, chest compressions, epinephrine, and atropine for the management of bradycardia in pediatric patients 7.

Considerations for Prehospital Care

• Prehospital care providers should be aware of the potential for elevated ICP and Cushing's triad in patients with bradycardia and take steps to manage these conditions appropriately 3.
• The use of noninvasive maneuvers, neuroprotective intubation and ventilation strategies, and pharmacologic therapies such as ketamine, lidocaine, corticosteroids, and hyperosmolar agents may be considered in the prehospital setting 3.
• However, the efficacy of these interventions in the prehospital setting is not well established, and further research is needed to determine the optimal management of bradycardia with suspected elevated ICP and Cushing's triad in the prehospital setting 7, 4, 5, 3, 6.