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.
References
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
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
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/
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