Podcast 871: Increased Intracranial Pressure and the Cushing Reflex - The Emergency Medical Minute

Podcast 871: Increased Intracranial Pressure and the Cushing Reflex

Contributor: Travis Barlock MD

Education Pearls:

  • The Cushing Reflex is a physiologic response to elevated intracranial pressure (ICP)

    • Cushing’s Triad: widened pulse pressure (systolic hypertension), bradycardia, and irregular respirations

  • Increased ICP results from systolic hypertension, which causes a parasympathetic reflex to drop heart rate, leading to Cushing’s Triad.

  • The Cushing Reflex is a sign of herniation

  • Treatment includes:

    • Hypertonic saline is comparable to mannitol and preferable in patients with hypovolemia or hyponatremia

      • Give 250-500mL of 3%NaCl

    • 20% Mannitol – given at a dose of 0.5-1 g/kg

      • Each additional dose of 0.1 g/kg reduces ICP by 1 mm Hg

    • 23.4% hypertonic saline is more often given in the neuro ICU

    • 8.4% Sodium bicarbonate lowers ICP for 6 hours without causing metabolic acidosis

  • Non-pharmacological interventions:

    • Raise the head of the bed to 30-45 degrees

    • Remove the c-collar to improve blood flow to the head

    • Hyperventilation induces hypocapnia, which will vasoconsrict the cerebral arterioles

    • You hyperventilate on the way to the OR. Otherwise, maintain normocapnia.


  1. Alnemari AM, Krafcik BM, Mansour TR, Gaudin D. A Comparison of Pharmacologic Therapeutic Agents Used for the Reduction of Intracranial Pressure After Traumatic Brain Injury. World Neurosurg. 2017;106:509-528. doi:10.1016/j.wneu.2017.07.009

  2. Bourdeaux C, Brown J. Sodium bicarbonate lowers intracranial pressure after traumatic brain injury. Neurocrit Care. 2010;13(1):24-28. doi:10.1007/s12028-010-9368-8

  3. Dinallo S, Waseem M. Cushing Reflex. [Updated 2023 Mar 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549801/

  4. Godoy DA, Seifi A, Garza D, Lubillo-Montenegro S, Murillo-Cabezas F. Hyperventilation therapy for control of posttraumatic intracranial hypertension. Front Neurol. 2017;8(JUL):1-13. doi:10.3389/fneur.2017.00250

Summarized by Jorge Chalit, OMSII | Edited by Meg Joyce & Jorge Chalit, OMSII



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