Diabetes Insipidus

PATIENT PRESENTATION:
51 yr old female, K.W. with a past medical history significant for only HTN, presented to the ER with SBP 276, L sided weakness, and covered in emesis.  GCS is a 7.  K.W. was placed on a Cardene® gtt to control BP, intubated, and a STAT CT scan of the head was performed which revealed a right basal ganglia hemorrhage with intra-ventricular extension; K.W. was transferred to the Neuro-Surgical ICU.  An external ventricular drain, (EVD), was placed in order to monitor intracranial pressures (ICP), and to drain off excess fluid in the brain.  The EVD is open to drain at 0cm H20 and output is bloody. Urinary output is being monitored by a Foley catheter and is adequate at approximately 100mL/hr and yellow in color.  During the 1300 assessment, 18 hrs after K.W.’s initial presentation, the urinary output is approximately 500mL and has lost some of the color.  During the 1400 assessment, the urinary is now 800mL and extremely dilute.

DIFFERENTIAL LIST:
Diabetes insipidus is strongly suspected

DIAGNOSIS:
Labs: Na+ 162, serum osmolality 315, urine specific gravity 1.001, urine osmolality 200
Vital Signs: HR: 87, BP: 155/67 (on 5mg/hr of Cardene®), SpO2: 100% on 60% FiO2, RR: 16 on vent
ICP: 18 (however K.W. has had multiple periods of sustained ICP’s in the 50’s)
Neuro Exam: K.W. has progressed to a 3T on the GCS. Pupils are 7mm and fixed bilaterally.  K.W. has no cough/gag/corneal reflexes and is breathing over the ventilator by one breath.

K.W. was diagnosed with neurogenic diabetes insipidus secondary to elevated ICP due to hemorrhagic stroke.

TREATMENT:
Treatment will include performing mL:mL replacement for urinary output greater than 150mL in one hour, (i.e. if K.W.’s urinary output is 500mL in one hour, replace 350mL via IV administration of 0.9% NS).  Monitoring DI labs q 4 hrs will also be done.  Treatment for this specific patient will include treating the underlying cause, which will be to control the ICP and continue to drain from the EVD.

OUTCOME:
Unfortunately, K.W.’s hemorrhage was so severe, causing such elevated ICP’s that it caused brain stem herniation and she did not make it.  The diabetes insipidus was a result of this hemorrhage and could not be corrected because the underlying cause could not be corrected.
Case created by Kelley Wicheta, 2011.