Permissive Hypernatremia: Comanagement of Intracranial Pressure

1Saint Joseph Mercy Hospital, Ann Arbor, Ml
2Saint Joseph Mercy Hospital, Ann Arbor, Ml
3Saint Joseph Mercy Hospital, Ann Arbor, Ml

Meeting: Hospital Medicine 2009, May 14-17, Chicago, Ill.

Abstract number: 206

Case Presentation:

A 17‐year‐old female was admitted to the surgical ICU after a motor vehicle accident. Her Glasgow coma score was 4. She had multiple traumatic injuries and required intubation. CT of the brain showed bilateral frontal and right temporal lobe hemorrhagic contusions, a complex basilar skull fracture, and severe cerebral edema. An intracranial pressure (ICP) monitor was emergently placed, Ventriculostomy drainage and levophed were used to control ICP and maintain cerebral perfusion pressure (CPP). Initial serum sodium was 138 mmol/L. On day 2 the nurses noted a high urine output up to 1790 cc/hour. Serum sodium rose acutely to 159 mmol/L. Our hospitalist service and endocrinology were urgently consulted. Serum and urine osmolarity (osm) were obtained, and central diabetes insipidus (Dl) was diagnosed. Urine output was replaced cubic centimeter for cubic centimeter with 0.2% normal saline, and a desmopressin drip was titrated to urine output. Serum sodium was initially brought to 149 mmol/L with a serum osmolarity of 306 mOsm/kg. Solucortef was started for possible adrenal insufficiency. Given the recent data on benefits of hypertonic saline in controlling cerebral edema, we proposed a goal sodium between 143 and 150 mmol/L and a goal serum osmolarity of 280–310 mOsm/kg. After extensive discussion, neurosurgery and endocrinology agreed. Desmopressin and percent sodium in IV fluids were adjusted accordingly. Mannitol was not required. On day 8, a reduction in serum sodium to 127 mmol/L resulted in a rise in ICP to 35 mm Hg. Mannitol was given acutely, and a pentobarbital coma was induced. Desmopressin was held, and 3% saline resulted in a rise in serum sodium and stabilization of ICP at 12 mm Hg. As cerebral edema improved, serum sodium was gradually allowed to normalize, and eventually the Dl resolved. After a prolonged hospitalization this patient made a remarkable recovery and within a year was back taking college classes.


We believe this case of permissive hypernatremia presents a novel approach to controlling ICP in a patient with severe head injury and diabetes insipidus. Traditionally, mannitol has been used in headinjured patients as the osmotic agent to acutely control intracranial pressure. Yet hypertonic saline solutions with forced hypernatremia have emerged as a promising alternative. Head injury with Dl is a unique condition in which the serum sodium is completely under our control. Given (1) the effectiveness of controlled hypernatremia in this patient, (2) the lack of need for mannitol when serum sodium was elevated, (3) the observed deleterious effects on ICP when sodium was allowed to drop, and (4) the excellent clinical outcome, we believe the use of permissive hypernatremia may warrant further investigation in head‐injured patients with Dl.


This case illustrates the importance of the hospitalist in comanaging the head‐injured patient and also introduces a novel approach to ICP management in diabetes insipidus.

Author Disclosure:

T. Tassava, none; N. Karenkova, none; M. Salameh, none.

To cite this abstract:

Tassava T, Karenkova N, Salameh M. Permissive Hypernatremia: Comanagement of Intracranial Pressure. Abstract published at Hospital Medicine 2009, May 14-17, Chicago, Ill. Abstract 206. Journal of Hospital Medicine. 2009; 4 (suppl 1). Accessed April 5, 2020.

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