Diabetes Insipidus

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

qw098

zyzzbrah
10+ Year Member
Joined
Oct 23, 2011
Messages
440
Reaction score
202
Dude just needs water cuz his pituitary gland isn't working so he isn't pumping out enough ADH...

How come I can't give my patient just water instead of D5W?
 
Dude just needs water cuz his pituitary gland isn't working so he isn't pumping out enough ADH...

How come I can't give my patient just water instead of D5W?
Probably don't want to lower his sodium too quickly and risk cerebral edema.
 
D5W will lower sodium just as quickly as free water, and you can give your patient ORAL free water. IV, however, is because you still need what ever fluid to be relatively isotonic or else the cells go poof (lyse).

...and yes, you don't want to lower it too quickly, thus you constantly monitor the sodium. You also want to give subq desmopressin titrated to urine output.
 
So, why doesn't oral water lyse the epithelial cells of the GIT?
Greater density of Na/K pumps and K and Cl leak channels on the luminal and basolateral surfaces and gap junctions between individual cells. A large water bolus is likely to cause the collective epithelium to swell only slightly. In contrast RBCs are little lonely cells with three Na/K pumps and are extremely susceptible to osmotic shifts.
 
Greater density of Na/K pumps and K and Cl leak channels on the luminal and basolateral surfaces and gap junctions between individual cells. A large water bolus is likely to cause the collective epithelium to swell only slightly. In contrast RBCs are little lonely cells with three Na/K pumps and are extremely susceptible to osmotic shifts.
Mucin
 
you'd have to give a bolus of concentrated sugar water do some damage in the GIT, IIRC
 
Top