17. Electrolytes & blood gas

Question 1

Incr in sodium (Na+)?

Answer 1

• Loss of low- Na+ (Hypotonic) fluid:
• Diuresis: Drugs(furosemide, corticosteroids, Mannitol), DM(osmotic), post obstructive (low USG)
• GIT losses: vomiting and diarrhoea
• Kidney disease
• Burn injuries and third space losses(peritonitis & pancreatitis)
• Loss of free water:
• Diabetes inspidus
• Panting (heat stroke, pyrexia, exercise, seizures)
• reduced water intake
• Increased Na+ retention
• Primary Hyperalaldosteronism(conns syndrome)
• Excessive Na+ from iv fluidor bicarbonate therapy, sodium phosphate enemas
• Ingestion of high Na+ foods/water

Question 2

Clinical signs of high Na+ ?

Answer 2

• Clinical signs: Due to shrinking of the brain
• weakness
• lethargy
• ataxia
• seizures
• stupor
• coma
• Mild<160
• Severe (neurological Csx): >170

Question 3

Decreased Na+ levels?

Answer 3

DECREASED:
• Hypoadrenocorticlsm (+/- inc K+) (rule out whipworm)
• Vomiting/diarrhoea
• Renal failure (Azotaemia)
• Over hydration - IV fluid diuresis
• Water retention:
> Heart failure
> Effusions (pleural and abdominal fluld)
• Artefact: Hyperlipidaemia, hyperproteinaemia,
hyperglycaemia
• Clinical signs: (due to swelling of the brain): Lethargy, seizures, coma
• Mild: <140 (<150 cats)
• Severe (Neurological CSx): <110- 120

Question 4

Increased Potassium ?

Answer 4

INCREASED:

• Reduced excretion:
Obstructive/rupture uropathy (FLUTD, urolith,
stricture) (azotaemia, anuria)
ii: Renal failure (anuric or oliguria) (azotaemia)
• Hypoadrenocorticism (Na+ can be normal (rule out whipworm and renal disease). Redistribution (ICF to ECF):
> Crush Injury (inc CK)
» Acidosis dec pH - commonly metabolic acidosis
> Thrombocytosis (inc CK)
> Artefact:
;> Haemolysed sample
“> Very high wcc
» Thrombocytosis

Question 5

Clinical signs for increased Potassium?

Answer 5

Clinical signs:

Weakness, collapse, flaccid paralysis, arrhythmia, bradyarrhythmias
•Mild: >5.5
•Moderate: >6.5

Severe: >9

Question 6

Decreased Potassium levels?

Answer 6

DECREASED:
• Persistent loss of high·K+ fluid
• Diarrhoea and vomiting
• Diuresis (Furosemide, IV fluids / low In K+)
• Insulin therapy (shifts into cells)
• Renal failure (polyuric- inc excretion) - (Azotaemia, dec . USG)
• Chronic anorexia
• Burmese polymyopathy (inc CK due to myopathy)
• Metabolic alkalosis (diuretics, vomiting, liver
disease, bicarbonate therapy)

Question 7

Clinical signs of decreased potassium levels?

Answer 7

Clinical signs: Weakness, lethargy, anorexia,
PU/PD, vomiting, neck ventroflexion (cats),
crouched gait
• Mild:3-3.5
• Moderate: 2.5 - 3
• Severe: <2.5

Question 8

Increased Chloride?

Answer 8

• Acidosis/ hypernatraemia

Question 9

Decreased Chloride?

Answer 9

Alkalosis / hyponatraemia

Question 10

Bicarbonate increased(alkalosis) and decreased (Acidosis)?

Answer 10

Question 11

PCO2 (art/venous) measure of alveolar ventilation incr and decr?

Answer 11

Question 12

PO2 (art/venous):
• Measure of alveolar to arterial gas exchange decr:

Answer 12

Question 13

Anion Gap cause of increased and decreased?

Answer 13

Question 14

Increased or decreased pH

Answer 14