PCCN Renal

Question 1

What influences water reabsorption?

Answer 1

ADH = vasopressin

Question 2

What influences sodium reabsorption?

Answer 2

Aldosterone

Question 3

Why is GFR used to measure renal function?

Answer 3

The lower the GFR, the less filtrate (urine) is produced

• *GFR effected by:
• epinephrine ↑BP by vasoconstriction, but ↓renal blood flow and GFR

Question 4

Hyperkalemia

• causes
• pt presentation
• ECG changes
• Treatment

Answer 4

K > 5.5 [causes heart to slow down]

**CAUSED by ACE inhibitors, ARBs, BB, K-sparing diuretics; ↑cell destruction (crash injuries, burns, rhabdomyolysis, acidosis), obvi renal failure

**↓HR, ↓BP, lethargy, confusion, cramping, diarrhea, irritability to flaccid paralysis, oliguria

• *ECG:
• ST segment depression
• peaked/elevated T waves
• wide QRS
• prolonged PR interval (1°AVB)
• flat or absent P waves
• asystole

Tx K>6.5
insulin to drive into cell
Kayexalate- removes K in stool
Hemodialysis

Question 5

Hypokalemia

Answer 5

K <3.5

CAUSED by alkalosis, diuretic therapy, vomit, diarrhea, NG suction, starvation, ↑corticosteroids

**↓HR, ↓BP, lethargy, confusion, cramping, diarrhea, irritability to flaccid paralysis, oliguria

• *ECG:
• ST segment depression (same for hyperK)
• flat or inverted T waves
• VT, Vfib, PVCs

Tx K>6.5
KCl and Mg replacement

Question 6

Hypernatremia

Answer 6

Na >145

↑ECF: ↑Na + H2O retention = overhydration (pt has wt gain, ↑BP, pulm edema, dyspnea, edema)

↓ECF: ↑Na (w/o water retention) = dehydration (weak, thready pulse and ↑HR)

ppl with head injury, lose thirst mechanism and irregular ADH; when ADH low (diabetes insipidus) pee alot.

Rx causes: mannitol, NS infusions, laxatives, antacids and ↑mineralcorticoids.

NO ECG CHANGES!!!

Question 7

phosphate important for what?

Answer 7

ATP, O2 delivery, enzyme fxn

…bones, cell membranes

Question 8

SIADH

Answer 8

syndrome of inappropriate antidiuretic hormone (ADH) secretion (SIADH) is defined by the hyponatremia and hypo-osmolality resulting from inappropriate, continued secretion or action of the hormone despite normal or increased plasma volume, which results in impaired water excretion. ==> HYPONATREMIA

Question 9

s/s Hypocalcemia

Answer 9

cramps, paresthesias, tetany, seizures

Question 10

What happens to Ca when pt on prolonged bedrest?

Answer 10

body thinks it doesn’t need the Ca and leaves bones for the blood, high Ca levels

hypercalcemia enhances digoxin

Question 11

Why do you need to hang Mg before K?

Answer 11

low Mg liberates K from inside cell to ECF, causing ↑renal secretion of K–> hypokalemia.

Hang/correct Mg first of K will continue to be excreted.

Question 12

Normal electrolyte levels

Answer 12

Na    135-145
K       3.5-5.0
Ca    9.0-10.5
Mg         1.8-3
Cl       96-106
P        3.0-4.5

Question 13

Hypercalcemia

Answer 13

Ca >10.5

cause: move out of beone, hyperparathyroidism, thiazide diuretics

Pt: HTN, lethargy, confusion to coma, fatigue, muscle weakness, N/V, constipation, anorexia

ECG: shorten ST seg, AVB–>cardiac arrest

Question 14

Hypocalcemia

Answer 14

Ca <8.5

cause: diarrhea, diuretic use, vit D def, hypoparathyroidism

ECG: prolonged QT interval and ST seg

Question 15

Hypophosphatemia

Answer 15

P <3.0

Cause: chronic alcoholism, malabsorption

Pt: muscle pain/tenderness, seizures, muscle weakness/wasting, PLATELET DYSFUNCTION, ↓BP↑HR

Question 16

Problems seen with renal failure

Answer 16

hyperkalemia
hypocalcemia
HTN
Acidosis
anemia
Azotemia