49 Electrolytes

Question 1

What is the free water deficit? 53F. 60 Kgs. CBG 322. Serum sodium 155 mg/dl

Answer 1

3.2L

Question 2

A 24F diabetic presents with vomiting and abdominal pain. She is dehydrated and Febrile. CBG shows 420 mg/dl. Na 134 mg/dl. K 4.8 mmol/ml. Creatinine is 1.6 mg/dl. What is her corrected sodium?

Answer 2

Corrected Na is 140

Question 3

Osmolality of human fluid

Answer 3

280-295 mOsm/kg

Question 4

Half life of AVP

Answer 4

10-20 minutes

Question 5

Site of action of AVP/vasopressin

Answer 5

V2 receptor of thick ascending loop of Henle (TALH) and

Principal cells of collecting duct

Question 6

Site where 2/3 of NaCl is reabsorbed? The remaining 1/3?

Answer 6

2/3 in Proximal tubule

1/3 in TALH

Question 7

Site sensitive to aldosterone

Answer 7

Distal convoluted tubile
Connecting tubule
Collecting duct

Question 8

Site sensitive to thiazide

Answer 8

Apical NaCl Co transporter

Question 9

More reliable signs of hypovolemia

Answer 9

Decreased jugular venous pressure
Ortho static Tachycardia
Orthostatic hypotension

Question 10

What is Orthostatic tachycardia? Orthostatic hypotension?

Answer 10

Orthostatic tachycardia: increase of 15-20 beats while standing
Orthostatic hypotension: 10-20 mmHg drop in blood pressure while standing

Question 11

More dependable measure of GFR: Creatinine or BUN?

Answer 11

Creatinine

Question 12

Decreased TBW. Decreased body sodium. Urine Na more than 20

Answer 12

Renal losses
Diuretic excess
Cerebral Salt wasting syndrome
Ketonuria

Question 13

Decreased TBW. Decreased body sodium. Urine Na less than 20

Answer 13

Extra renal losses
Vomiting
Diarrhea
Third spacing of fluids
Burns
Pancreatitis
Trauma

Question 14

Euvolemia. Hyponatremia. Urine sodium more than 20

Answer 14

Hypothyroidism
Stress
Drugs
SIADH
Glucocorticoids deficiency

SS HGD
Sige higda

Question 15

Increased TBW. Decreased body sodium. Urine sodium less than 20

Answer 15

Acute or chronic renal failure

Question 16

Increased TBW. Decreased body sodium. Urine Na less than 20

Answer 16

Nephrotic syndrome
Cirrhosis
Cardiac failure

Question 17

Rare cause of hypovolemic Hyponatremia and inappropriate natriuresis in association with Intracranial disease

Answer 17

Cerebral Salt wasting

Question 18

Management of cerebral Salt wasting

Answer 18

Aggressive NaCl repletion

Question 19

Most frequent cause of euvolemic hyponatremia

Answer 19

SIADH

Question 20

Common causes of SIADH

Answer 20

Pulmonary disease: pneumonia, tuberculous, pleural effusion

CNS disease: tumor, Sah, Meningitis

Question 21

Loss of oligodendrocytes due to rapid reaccumulation of organic osmolytes; brain area classically affected

Answer 21

Osmotic demyelination syndrome;

Lesion affects the pons, cerebellum, lateral geniculate, thalamus, putamen, cerebral cortex or subcortex

Question 22

Na concentration correction allowed in 24 hours

Answer 22

8-10 mM within first 24 hours

Not more 18 mM within first 48 hours

Question 23

Cornerstone in the therapy of hyponatremia

Answer 23

Water deprivation

Question 24

Quick indicator of electrolytre- free water excretion

Answer 24

Urine to plasma electrolyte ratio (urinary Sodium + urinary Potassium/ plasma sodium)

Question 25

Interpretation of urine to plasma electrolyte ratio

Answer 25

More than 1: water aggressive restricted to less than 500 ml/day About 1: fluid restricted to 500-700 ml Less than 1: water restricted to 1 L/day

Question 26

Causes of Acute Hyponatremia

Answer 26

``` Thiazides Polydipsia MDMA (ecstasy) Exercise Polydipsia Colonoscopy preparation Glycine irrigation in TURP or uterine surgery ```

Question 27

Causes of hypernatremia. ECF volume increased. Minimum volume of maximally concentrated urine, Yes.

Answer 27

Insensible water loss GI water loss Remote renal water loss

Question 28

Causes of hypernatremia. Increased ECF volume. Minimal maximally concentrated urine, No. Urine osmole excretion rate more than 750 mOsm/day

Answer 28

Diuretic use | Osmotic diuresis

Question 29

Causes of hypernatremia. Increased ECF volume. Minimal maximally concentrated urine, No. Urine osmole excretion rate less than 750 mOsm/day. Desmopressin given. Urine osomolality increased

Answer 29

Central diabetes insipidus

Question 30

Causes of hypernatremia. Increased ECF volume. Minimal maximally concentrated urine, No. Urine osmole excretion rate less than 750 mOsm/day. Desmopressin given. Urine osomolality unchanged

Answer 30

Nephrologenic diabetes insipidus

Question 31

Causes of Hypokalemia. Decreased intake

Answer 31

Starvation | Clay ingestion

Question 32

Causes of Hypokalemia. Redistribution to cells

Answer 32

``` Metabolic alkalosis Bronchodilators/tocolytics Insulin Downstream regulation of NaKATPase: theophylline, caffeine Thyrotoxic periodic paralysis --- Vit B administration TPN ```

Question 33

Hypokalemia. Urine K less than 15. ABG normal

Answer 33

Extra renal cause | Profuse sweating

Question 34

Hypokalemia. Urine K less than 15. ABG metabolic acidosis

Answer 34

GI K loss

Question 35

Hypokalemia. Urine K less than 15. ABG metabolic alkalosis

Answer 35

Diuretic use Vomiting or stomach drainage Profuse sweating

Question 36

Hypokalemia. Urine K more than 15. TTKG more than 4. BP high. Aldosterone high. Renin high.

Answer 36

``` Renal loss Increased Distal K secretion -- Renal artery stenosis Renin secreting tumor Malignant hypertension ```

Question 37

Hypokalemia. Urine K more than 15. TTKG less than 2.

Answer 37

Increased tubular flow | Osmotic diuresis

Question 38

Hypokalemia. Urine K more than 15. TTKG more than 4. BP high. Aldosterone high. Renin low

Answer 38

Increased Distal K secretion --- Primary aldosteronism Familial hyperaldosteronism type I

Question 39

Hypokalemia. Urine K more than 15. TTKG more than 4. BP high. Aldosterone low. Renin normal. Cortisol normal

Answer 39

Liddle syndrome Licorice Syndrome of apparent mineralocorticoid excess

Question 40

Hypokalemia. Urine K more than 15. TTKG more than 4. BP high. Aldosterone low. Renin normal. Cortisol high

Answer 40

Cushing syndrome

Question 41

Hypokalemia. Urine K more than 15. TTKG more than 4. BP low to normal. ABG metabolic acidosis

Answer 41

RTA DKA Amphotericin B Acetazolamide

Question 42

Hypokalemia. Urine K more than 15. TTKG more than 4. BP low to normal. ABG metabolic alkalosis. Urine Chloride less than 10

Answer 42

Vomiting | Chloride diarrhea

Question 43

Hypokalemia. Urine K more than 15. TTKG more than 4. BP low to normal. ABG metabolic alkalosis. Urine Chloride more than 20. Urine Ca/CR ratio more than 0.2

Answer 43

Loops diuretic | Barterrs syndrome

Question 44

Hypokalemia. Urine K more than 15. TTKG more than 4. BP low to normal. ABG metabolic alkalosis. Urine Chloride more than 20. Urine Ca/CR ratio less than 0. 15

Answer 44

Thiazides diuretic | Gitelmans syndrome

Question 45

Causes of Hyperkalemia. Pseudo hyperkalemia

Answer 45

Cellular efflux: thrombocytosis, erythrocytosis, leukocytosis