12. Replace water deficit
Assumes no gain of sodium
The change in sodium is entirely due to loss of
water
The % body water lost equals delta Na divided by
the ideal (or prior) Na
To calculate the water deficit take % water lost
and multiply total body water
Na now – Na ideal
x Kg x 0.5*
Na ideal
13. Calculate free water deficit
Na now – Na ideal
x Kg x 0.5*
Na ideal
The kg x 0.5 is an estimate of total body water
The asterisk is because you need to estimate the
multiplier
14. The older and fatter you are
the less water you are.
We use 50% as standard
because most people with
hypernatremia are older and
fatter than the 60% estimated
for men.
15.
16.
17.
18. Ideal weight: Females: 45 kg
+ 2.3 kg for every inch over 5 feet
Males: 50 kg
Adjusted weight: ideal weight + 0.4 (actual body weight – ideal weight)
19. Calculate free water deficit
Na now – Na ideal
x Kg x 0.5*
Na ideal
1. Na 165; Prior Na 144; Body Wt 70 kg; %H2O 60%
2. Na 185; Prior Na 138; Body Wt 23 kg; %H2O 70%
3. Na 155; Prior Na 142; Body Wt 76 kg; %H2O 50%
4. Na 152; Prior Na 140; Body Wt 65 kg; %H2O 40%
20. Calculate free water deficit
Na now – Na ideal
x Kg x 0.5*
Na ideal
Na 165
Prior Na 144
Body Wt 70 kg
%H2O 60%
21. Calculate free water deficit
Na now – Na ideal
x Kg x 0.5*
Na ideal
Na 165
Prior Na 144
H2O deficit = 6.1 liters
Body Wt 70 kg
%H2O 60%
22. Calculate free water deficit
Na now – Na ideal
x Kg x 0.5*
Na ideal
Na 185
Prior Na 138
Body Wt 23 kg
%H2O 70%
23. Calculate free water deficit
Na now – Na ideal
x Kg x 0.5*
Na ideal
Na 185
Prior Na 138
H2O deficit = 5.5 liters
Body Wt 23 kg
%H2O 70%
24. Calculate free water deficit
Na now – Na ideal
x Kg x 0.5*
Na ideal
Na 155
Prior Na 142
Body Wt 76 kg
%H2O 50%
25. Calculate free water deficit
Na now – Na ideal
x Kg x 0.5*
Na ideal
Na 155
Prior Na 142
H2O deficit = 3.5 liters
Body Wt 76 kg
%H2O 50%
26. Calculate free water deficit
Na now – Na ideal
x Kg x 0.5*
Na ideal
Na 152
Prior Na 140
Body Wt 65 kg
%H2O 40%
27. Calculate free water deficit
Na now – Na ideal
x Kg x 0.5*
Na ideal
Na 152
Prior Na 140
H2O deficit = 2.2 liters
Body Wt 65 kg
%H2O 40%
33. Hypernatremia
Generation hypertonic saline
hypertonic dialysate
gain of sodium bicarbonate
tube feedings or TPN
loss of water salt tablets
primary hyperaldosteronism
Maintenance
Cushing’s syndrome
congenital adrenal hyperplasia
34. Hypernatremia
Generation sweating, burns
osmotic diarrhea
gain of sodium central diabetes insipidus
nephrogenic diabetes insipidus
loss of water congenital
ATN, CKD
Maintenance
lithium
hypercalcemia
hypokalemia
osmotic diuresis
38. Hypernatremia
Generation Generation increases water
demand. As long as increased
gain of sodium demand is met the sodium
remains normal
loss of water
Maintenance
39. Hypernatremia
Generation Generation increases water
demand. As long as increased
gain of sodium demand is met the sodium
remains normal
loss of water
Maintenance
Patient had labs 2-wks prior:
143 106 28
3.3 23 1.2
45. How about some
more history...
Lap chole was being done for
gall stones and increased in
abdominal pain
The polydipsia had been
ongoing for 3-6 months
ROS revealed increased DOE
and cough
No history of lithium use
64. Mobilization of bone
๏ Hypercalcemia of malignancy
๏ Humoral hypercalcemia (PTHrp)
๏ Direct invasion of bone (OAF)
๏ Breast Cancer
๏ Multiple Myeloma
๏ Lung cancer
๏ Primary and Tertiary Hyperparathyroidism
68. Patient was started on oral prednisone
Alternatives include ketoconzole and plaquinil
Rarely requires bisphosphonates
The case occurred in July 2008
69. A week after the patient’s calcium was 10 mg/dL
The patient still had polydipsia and polyuria
When surgical team made her NPO to take her to
the OR she again became hypernatremic
NA NA
NPO
142 158
90. 160
158
Sodium (mmol/L)
150
149
140 144
138
130 132
120
day 1 day 2 day 3 day 4 day 5
7,000
Urine output (mL)
6,050
5,000
3,900
3,000 3,200
2,200 2,400
1,000
day 1 day 2 day 3 day 4 day 5
93. Notes on treatment
central diabetes insipidus responds to ddAVP
Unlike vasopressin, ddAVP does not cause
vasoconstriction
94. Notes on treatment
central diabetes insipidus responds to ddAVP
Unlike vasopressin, ddAVP does not cause
vasoconstriction
Patient had labs two- 143 106 28
weeks prior 3.3 23 1.2
95. Notes on treatment
central diabetes insipidus responds to ddAVP
Unlike vasopressin, ddAVP does not cause
vasoconstriction
Patient had labs two- 143 106 28
weeks prior 3.3 23 1.2
It is a cosmetic drug