Fluid and Electrolytes Ca and PO4^-3 Flashcards Preview

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Flashcards in Fluid and Electrolytes Ca and PO4^-3 Deck (44):
1

Normal Calcium

8.5-10.5 mg/dL

2

Where is the calcium in the body

>99% in skeleton
ECF has 0.5%

3

ECF Calcium

about 46% is bound to albumin

4

What is the active form of Calcium

Ionized or free Calcium

5

Most common cause of hypocalcemia

Hypoalbuminemia

6

Reduced serum calcium + PO4^3-

Elevated phosphorous can cause reduced Ca
Reduced Ca can lead to increase PTH

7

Increased parathyroid hormone secretion leads to

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

8

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

Increased serum Ca which leads to increased calcitonin

9

Increased renal activation 1,25 dihydroxy vit D3 leads to

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

10

Hypocalcemia can be seen in

Elderly
Malnourished pts
Pts receiving NaPO4

11

Causes of hypoCa

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

12

Vitamin D + Ca

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

13

HypoMg + Ca

Unresponsive to replacement and unresponsive to PTH

14

TIssue consumption of Ca

Sever pancreatitis secondary to Ca turning into SOAP
Sepsis
Rhabdo

15

Hungry Bone Syndrome + Ca

Recent thyroidectomy
Bone is avidly incorporating Ca/P into bone

16

Drug induced hypoCa

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

17

Symptoms of hypoCa

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

18

Chvostek's sign + HypoCa

Tap on their cheek and their mouth comes up

19

Trousseau's Sign + HypoCa

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

20

HyperCa + EKG

Shortened ST interval
Arrhythmias

21

HypoCa + EKG =

Prolong ST interval

22

Acute Symptomatic Hypocalcemia Treatment

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

23

Rate of Ca infusion

No more than 60 mg per minute bc of cardiac dysfunction

24

Ca + Precipitation

Don't add bicarbonate or phosphate

25

Chronic Asymptomatic HypoCa Treatment

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

26

Calcium chloride =

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

27

Calcium gluconate =

9% elemental Ca

28

Normal Phosphate

2.5-4.5 mg/dL

29

Phosphorus is needed for

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

30

***Phosphorus is mainly

intracellular
SERUM LEVELS DO NO ACCURATELY REFLECT TOTAL BODY STORES

31

Normal Levels for Children less than 12

4-5.6 mg/dL

32

Phosphorous homeostasis

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

33

Mild to moderate hypoP

1-2 mg/dL

34

Sever hypoP

less than 1 (symptoms)

35

Causes

Decreased GI absorption
Reduced tubular reabsorption
Internal redistribution

36

Decreased GI absorption causing hypoP

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

37

Reduced tubular reabsorption causing hypoP

Hyperparathyroidism
Burn recovery
Faconi syndrome

38

Internal redistribution causing hypoP

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

39

Define refeeding syndrome

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

40

Major conditions associated with severe hypoP

Alcoholism, IV TPN
Antacids
Treatment of severe DKA

41

Symptoms of hypoP

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

42

Treatment of HypoP

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

43

Monitoring with treatment of HypoP

Q6H

44

Mild-moderate or asymptomatic hypoP Treatment

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