Electrolytes

Question 1

True or False

Answer 1

Hypokalemia prolongs post-op ileus

Question 2

Hypomagnesemia is most commonly seen in

Answer 2

ALCOHOLICS!

Question 3

Magnesium is first required before XXX can be restored

Answer 3

Potassium

Question 4

Hypomagnesemia impairs parathyroid hormone….resulting in

Answer 4

hypocalcemia

* MUST replace magnesium before attempting to replace Calcium*

Question 5

S&S of Hypomagnesemia

Answer 5

muscular weakness, arrhythmia, CNS depression, seizure

Question 6

S&S of Hypermagnesemia

Answer 6

seen in acute/chronic renal failure
delayed cardiac conduction (AV block)
cardiac arrest
hyporeflexia
respiratory depression

Question 7

What is the goal Mg level

Answer 7

2.0 mg/dl (normal 1.5-2.5)

Question 8

Magnesium replacement

Answer 8

can aggressively be replaced
if Mg 1.7-1.9: MgSo4 1g IVPB
if Mg 1.3-1.6: MgSO4 2g IVPB
if Mg <1.3: MgSO4 2g x2 runs

Question 9

Hypokalemia is common in…

Answer 9

general surgery patients

Question 10

Potassium replacement

Answer 10

KCL IV BURNS!!!!

oral K is better, but some patients are NPO

Question 11

Goal serum K+ level

Answer 11

4.0 (normal: 3.5-5.0)
1 run K+ should inc serum K+ by 0.1 mg
**those with poor renal function are prone to retaining K+

Question 12

Calcium exists in two forms

Answer 12

Free Ca, albumin bound Ca

Free Ca does the work

Question 13

MC cause of low serum total Ca+2

Answer 13

LOW ALBUMIN

Question 14

Corrected Ca

Answer 14

[(normal albumin (4.0)- serum albumin)x 0.8 ]+ Ca+

Question 15

Calcium Replacement

Answer 15

Calcium gluconate

Calcium chloride –> must be given via central line so gluconate is often easier

Question 16

Where is hyperphosphatemia seen?

Answer 16

in pt with ischemic bowel, acidosis

excess P binds to Ca+2 and drives calcium WAY DOWN

Question 17

Phosphate

Answer 17

2.4-4.1
lost via kidney, diarrhea, NG tube suctioning
likely to result in respiratory alkalosis
replace VERY SLOWLY
20-40 mmol NaPhos or KPhoa over 4-6 hours

Question 18

severe hypophosphatemia S&S

Answer 18

**associated w/ CHF***
confusion 
stupor
seizure
coma

Question 19

Refeeding Syndrome

Answer 19

occurs in malnourished patients who are fed high carb loads which results in massive insulin production, thus leading to Phos, Mg, K all being driven intracellularly and drastically dropping serum levels.
can result in inc CO2 leading to tachypnea, dyspnea
***begin feeding SLOWLY