Etiology of acid base and electrolyte disorders

Written by Dr.Md.Redwanul Huq (Masum)
Tuesday, 22 January 2013 04:31

Causes of Hypernatraemia:

1. Inadequate water retention (i.e. excessive water loss) by kidney:

i) Diabetes insipidus

ii) Diabetic ketoacidosis

iii) Hyperosmolar non- ketotic diabetic coma

2. Excessive Na+ retention :

i) Hyper-aldosteronism

ii) Cushing Syndrome

3. Excessive Na+ intake:

i) Diet

ii) Hypertonic sodium solution

4. Increased loss of water through lungs and skin:

i) Fever

ii) Hyperventilation

iii) Hot environment

iv) Hypothyroidism

5. Inadequate water intake.

Causes of hyponatraemia:

Causes of hyponatremia are-

A. Hyponatraemia associated with decreased extracellular fluid(ECF) volume

(i.e.depletional hyponatraemia):

1. Gastrointestinal tract (GIT) loss:

i) Diarrhea

ii) Vomiting

iii) Sequestration of fluid in bowel as in intestinal obstruction or paralytic ileus

iv) Fistula

2. Renal loss:

i) Addison’s disease

ii) Chronic renal failure,

iii) Salt losing nephropathy

iv) Use of excessive diuretics (e.g. osmotic diuretics)

v) Chronic interstitial nephritis

vi) Polycystic kidney disease

3. Cutaneous loss-

i) Severe burn

ii) Excessive sweating

4. Inadequate intake of salt due to environmental deprivation or inadequate therapeutic replacement

5.Metabolic acidosis.

B. Hyponatraemia associated with normal or slightly increased ECF volume:

1. Syndrome of inappropriate ADH secretion (SIADH) due to-

i) Bronchogenic carcinoma

ii) Carcinoma pancreas

iii) Dudenal carcinoma

iv) Cerebrovascular accident

v) Bronchietasis

vi) Pneumonia

2. Excessive intravenous fluid

3. Hypothyroidism

4. Psychogenic polydypsia.

C. Hyponatraemia associated with increased ECF volume: (i.e. dilutional hyponatraemia):

1. Cirrhosis of liver

2. Congestive cardiac failure

3. Nephrotic syndrome.

Causes of Metabolic acidosis:

Causes of Metabolic acidosis are as following-

1. Accumulation of excessive acids in plasma:

i) Lactic acidosis

ii) Ketoacidosis (e.g. Diabetic ketoacidosis)

iii) Salicylate poisoning

iv) Methanol poisoning

2. Decreased excretion of acids from plasma:

i) Acute renal failure

ii) Chronic renal failure

iii) Distal renal tubular acidosis

3. Bicarbonate loss:

i) Diarrhoea

ii) Uretero-sigmoidostomy

iii) Intestinal fistula.

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