Electrolytes

Question 1

What is the normal level of serum Sodium?

Answer 1

(135-145)

Question 2

Severe hypoNa range and symptoms

Answer 2

< 120 mmol/L

Seizure - coma - resp. Arrest - brainstem herniation - death

Question 3

Patient with sNa < 135 - and 280mOsm/L

Answer 3

PSEUDO-HYPONATREMIA:

Markedly ⇑ lipids OR Proteins (e.g., hyperproteinemia, multiple myeloma)

Question 4

Hyponatremia ( sNa < 135 ) - > 280 mOsm/L

Answer 4

HYPERTONIC hyponatremia
1- Significant hyperglycemia
2. Presence of osmoles (e.g., ethanol, glycine, sorbitol, mannitol or albumin) = ⇑ Osmolar gap

Question 5

Corrected sNa equation?

Answer 5

Corrected sNa =

Measured sNa + [(Serum glucose - 100)/100) x 1.7]

Question 6

How do we know if the patient have hypertonic hyponatremia ?

Answer 6

1- calculate corrected sNa

2- If normal ⇒ Hyperglycemia induced hyponatremia Treatment of hyperglycemia will return sNa to normal

Question 7

What do we do if the patient have low osmolality/ ( hypotonic )?

Answer 7

Assess vol. status
1- hypovolemic
2- Euvolemic
3- hypevolemic

Question 8

Dwhat are the symptoms of Hypovolemic?

Answer 8

Deficit of both total body Na & TBW, but Na deficit exceeds TBW deficit
Na loss&raquo_space; water loss

Orthostasis, hypotension, tachycardia, dry mucous membranes, CNS changes

Question 9

Causes of Hypovolemic hypoNa?

Answer 9

If UNa < 20mEq/L = External loss
Considerable GIT losses: Vomiting, diarrhea, laxative abuse
Profuse sweating

If UNa > 20mEq/L = Renal loss
Diuretics: Thiazides and loop
Hypoadrenalism (AI)-Addison’s Disease (low cortisol & aldosterone) Cerebral (renal) salt wasting syndrome

Question 10

Hypovolemic (⇓ ECFV) - TREATMENT

Answer 10

• Discontinue diuretics
• Treatment of underlying disorder
• NS preferred, LR can be used
• Hypertonic saline (3% or 5% NaCl) for patients with severe
  hyponatremia

Question 11

Na deficit (mmol) =

Answer 11

Na deficit (mmol) = TBW X (desired sNa− current sNa)
- 140 mmol/L is the desired sNa

Question 12

Hypervolemic hypoNa symptoms

Answer 12

Water gain > Na gain

Peripheral and pulmonary edema, variable blood pressure

Question 13

Hypervolemic (⇑ ECFV) - Dilutional Hyponatremia causes

Answer 13

Heart failure - Liver cirrhosis - Nephrotic syndrome, Renal artery stenosis, Kidney failure

Question 14

Hypervolemic treatment

Answer 14

Na and fluid restriction in conjunction with treatment of the underlying disorder

salt and water restrictions are used in the setting of
CHF along with loop diuretic, ACEI, and spironolactone

Question 15

Euvolemic hypoNa symptoms

Answer 15

of volume overload, and thus patients will appear euvolemic upon physical examination

Symptoms depends on severity of hyponatremia

⇔ TBNa, ⇑ TBW and ECFV

Question 16

Euvolemic hypoNa causes

Answer 16

1) SIADH: Malignancy - CNS (trauma, tumor, meningitis,stroke) - Pulmonary (pneumonia, ARDS, TB)
2) Medications induced SIADH
3)