Fluid and Electrolytes Ca and PO4^-3

Question 1

Normal Calcium

Answer 1

8.5-10.5 mg/dL

Question 2

Where is the calcium in the body

Answer 2

> 99% in skeleton

ECF has 0.5%

Question 3

ECF Calcium

Answer 3

about 46% is bound to albumin

Question 4

What is the active form of Calcium

Answer 4

Ionized or free Calcium

Question 5

Most common cause of hypocalcemia

Answer 5

Hypoalbuminemia

Question 6

Reduced serum calcium + PO4^3-

Answer 6

Elevated phosphorous can cause reduced Ca

Reduced Ca can lead to increase PTH

Question 7

Increased parathyroid hormone secretion leads to

Answer 7

Increased clast and blast in bone to increase Ca mobilzation
Increased renal Ca reabsorption and decrease PO4 reabsorption
Increased renal activation 1,25 dihydroxy vit D3

Question 8

Increased clast and blast in bone to increase Ca mobilzation & increased renal Ca reabsorption and decrease PO4 reabsorption leads to

Answer 8

Increased serum Ca which leads to increased calcitonin

Question 9

Increased renal activation 1,25 dihydroxy vit D3 leads to

Answer 9

Increased intestinal Ca and PO4 absorption which leads to increased serum Ca which leads to increased calcitonin

Question 10

Hypocalcemia can be seen in

Answer 10

Elderly
Malnourished pts
Pts receiving NaPO4

Question 11

Causes of hypoCa

Answer 11

Vit D deficiency (renal failure)
HypoMg
Tissue consumption of Ca
Hungry bone syndrome (renal failure)
Drug Induced

Question 12

Vitamin D + Ca

Answer 12

Activation of Vit D leads to increased Ca/P absorption so if there is not enough Vit D there is not enough Ca/P absorption

Question 13

HypoMg + Ca

Answer 13

Unresponsive to replacement and unresponsive to PTH

Question 14

TIssue consumption of Ca

Answer 14

Sever pancreatitis secondary to Ca turning into SOAP
Sepsis
Rhabdo

Question 15

Hungry Bone Syndrome + Ca

Answer 15

Recent thyroidectomy

Bone is avidly incorporating Ca/P into bone

Question 16

Drug induced hypoCa

Answer 16

Furosemide, calcitonin, bisphosphonates
Chelating agents (citrate and EDTA)
Ethylene glycol

Question 17

Symptoms of hypoCa

Answer 17

Increased pH (more Ca bind to albumin)
Muscle cramps, tetany
Depression, anxiety, confusion
Prolong QT interval

Question 18

Chvostek’s sign + HypoCa

Answer 18

Tap on their cheek and their mouth comes up

Question 19

Trousseau’s Sign + HypoCa

Answer 19

Put a blood pressure cuff on pt and their hand will retract towards arm

Question 20

HyperCa + EKG

Answer 20

Shortened ST interval

Arrhythmias

Question 21

HypoCa + EKG =

Answer 21

Prolong ST interval

Question 22

Acute Symptomatic Hypocalcemia Treatment

Answer 22

100-300 mg of Ca IV over 5-10 minutes (gluconate)

- Last for 1-2 hours so continuous infusion of 0.5-2 mg/kg/hr

Question 23

Rate of Ca infusion

Answer 23

No more than 60 mg per minute bc of cardiac dysfunction

Question 24

Ca + Precipitation

Answer 24

Don’t add bicarbonate or phosphate

Question 25

Chronic Asymptomatic HypoCa Treatment

Answer 25

``` If hypoMg, give Mg No bisphosphonates bc of hungry bone Oral Ca and Vit D - Ca: 1 to 3 g/day up to 2 to 8 g/day - D: 50,000 u/d but if renal use 1,25 OH D3 0.5-3 mcg/d ```

Question 26

Calcium chloride =

Answer 26

27% elemental Ca | - Often leads to hyper symptoms due to high potentcy

Question 27

Calcium gluconate =

Answer 27

9% elemental Ca

Question 28

Normal Phosphate

Answer 28

2.5-4.5 mg/dL

Question 29

Phosphorus is needed for

Answer 29

``` Cell membranes, nucleic acids, mitochondrial function Enzymatic reaction regulation Oxygen and hemoglobin dissociation High energy bonds of ATP Bone formation ```

Question 30

***Phosphorus is mainly

Answer 30

intracellular | SERUM LEVELS DO NO ACCURATELY REFLECT TOTAL BODY STORES

Question 31

Normal Levels for Children less than 12

Answer 31

4-5.6 mg/dL

Question 32

Phosphorous homeostasis

Answer 32

Western Diet provides 800-1600 mg and 60-80% is absorbed - Low Vit D and low P increase absorption - Reabsorption is inhibited by PTH and increased Vit D3

Question 33

Mild to moderate hypoP

Answer 33

1-2 mg/dL

Question 34

Sever hypoP

Answer 34

less than 1 (symptoms)

Question 35

Causes

Answer 35

Decreased GI absorption Reduced tubular reabsorption Internal redistribution

Question 36

Decreased GI absorption causing hypoP

Answer 36

``` P binding drugs: aluminum agents, sevelamer Decreaseintake Glucocorticoids Vit D def Hypoparathyroidism Diarrhea Steatorrhea (fat in the poop) ```

Question 37

Reduced tubular reabsorption causing hypoP

Answer 37

Hyperparathyroidism Burn recovery Faconi syndrome

Question 38

Internal redistribution causing hypoP

Answer 38

``` Refeeding syndrome IV nutrition Parathyroidectomy (hungry bone) Insulin Glucagon Calcitonin ```

Question 39

Define refeeding syndrome

Answer 39

Mitochondria are so starved for energy bc no enough P that when it enters it goes ECF to ICF and paralyzes the body

Question 40

Major conditions associated with severe hypoP

Answer 40

Alcoholism, IV TPN Antacids Treatment of severe DKA

Question 41

Symptoms of hypoP

Answer 41

``` Encephalopathy Impaired myocardial contracility (CHF) Myopathy, dysphagia Hemolysis, defective clotting Prolonged rickets and osteomalacia ```

Question 42

Treatment of HypoP

Answer 42

12-14 mmol/L to TPN Infusion fof 15 mmol/250 mL of D5W or NS over 3 hours Doses of 15-30 mmol can be given over 1-3 hrs if pts has normal Ca

Question 43

Monitoring with treatment of HypoP

Answer 43

Q6H

Question 44

Mild-moderate or asymptomatic hypoP Treatment

Answer 44

Oral P salts 1.5-2 g daily in divided doses and should correct in 7-10 days - Renal insufficiency reduced to 1 g