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. 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