Fluid & Electrolytes

Question 1

Normal GFR value:

Answer 1

150-250 L/24 hours

Question 2

Which estimate of GFR OVERestimates? UNDERestimates?

Answer 2

Over –> creatinine

Under –> BUN (“bun-derestimate”)

Question 3

As patient approaches ESRD, a more accurate approximation of GFR is what?

Answer 3

an average of Creatinine and BUN

Question 4

What’s a normal BUN:creatine ratio?

Answer 4

10:1

Question 5

A 4 variable GFR takes what else into account beside creatinine clearance?

Answer 5

age, weight, and race

Question 6

How does total body water change with age and sex?

Answer 6

More in men,

Decreases with age

Question 7

How are changes in total body water content best assessed?

Answer 7

weight

Question 8

How is circulating volume of water assessed?

Answer 8

BP, JVD, pulse

Question 9

To assess cause and severity of RENAL abnormalities, evaluation should include:

Answer 9

1) disease DURATION
2) UA
3) GFR

Question 10

Diagnosis and treatment of a FLUID and ELECTROLYTE disorder are based on:

Answer 10

1) careful history
2) Assessment of total body water and distribution
3) serum electrolytes (CBC)
4) urine electrolytes (UA)
5) serum osmolality

Question 11

What electrolyte is most checked with a serum OSMOLALITY?

Answer 11

SODIUM

Question 12

HYPOnatremia is defined by what serum Na osmolality?

Answer 12

< 136 mmol/L

Question 13

Hyponatremia occurs when total body water status is low, normal, or high?

Answer 13

ALL of them - natremic states cannot be assessed without first assessing the fluid and water status of the patient.

Question 14

Signs/Symptoms of hypoNAtremia:

Answer 14

Most commonly: ALTERED MENTAL STATUS (agitation, disorientation, apathy)
Also: Anorexia, Nausea, Hypothermia, Lethargy, depressed DTRs,
Severe: seizure, coma, death

Question 15

Infusion of hypertonic saline is usually not necessary unless:

Answer 15

1) Na <120 mmol/L
2) altered mental status
3) patient is fluid restricted due to HF, chronic renal failure

Question 16

Patients with hyponatremia caused by low TOTAL BODY SODIUM often exhibit signs and symptoms of:

Answer 16

DEHYDRATION - thirst, dry mucous membranes, weight loss, sunken eyes, diminished urine output, and diminished skin turgor

Question 17

HYPOosmolar HYPOnatremia with EUvolemia, caused by:

Answer 17

1) ADH problems (SIADH, renal failure)
2) Adrenal insufficiency
3) Hypothyroidism
4) Polydipsia

Question 18

HYPOosmolar HYPOnatremia with HYPERvolemia, caused by:

Answer 18

Edematous states - HF, liver cirrhosis, nephrotic syndrome, CKD

Question 19

HYPOosmolar HYPOnatremia with HYPOvolemia, caused by:

Answer 19

thiazide diuretics
diarrhea
vomiting
blood loss
hypoaldosteronism

Question 20

ISOosmolar HYPOnatremia, caused by:

Answer 20

Hyperlipidemia

Hyperproteinemia

Question 21

HYPERosmolar HYPOnatremia, caused by:

Answer 21

Hyperglycemia

Question 22

Signs/Symptoms of DEHYDRATION?

Answer 22

Orthostatic hypotension
Oliguria
Lethargy, irritability, weakness

Question 23

Causes of SIADH:

Answer 23

CNS disorders
Lung disease
Cancer
Drugs