Arterial Blood Gas (ABG) Interpretation and Electrolyte Imbalance

Practice flashcards covering ABG normal ranges, metabolic and respiratory acidosis/alkalosis, anion gap calculations, and clinical causes.

Normal pH range

$$7.35 - 7.45$$

Normal $pCO_2$ range

$$35 - 45\,mmHg$$

Normal $HCO_3$ range

$$22 - 26\,mEq/L$$

Normal $pO_2$ range

$$80 - 100\,mmHg$$

Normal Oxygen saturation

$$98 - 100\%$$

Anion gap (AG) Formula (without Potassium)

$AG = Na - (Cl + HCO_3)$ with a normal range of $6-12mEq/L$ .

High Anion Gap causes

DKA, Lactic acidosis, Renal failure, Metformin toxicity, Sepsis, Salicylate overdose, Rhabdomyolysis, and Starvation.

Normal Anion Gap causes

Renal tubular acidosis, Diarrhoea, and Pancreatic fistula.

Metabolic aidosis cause

DKA, lactic acidosis, diarrhoea, kidney failure, Medicine over dose such as salicylates, metformin, anti-retrovirals

Metabolic Alkslosis cause

vomitting:pyloric stenosis, GIT infection, self-induced. Hypokalaemia: diuretics, hyperaldosteronism, villous adenoma

respiratory alkalosis cause

panic attack, anxiety, lung disease (mild,moderate) pulmonary embolism, hypoxemia,fever, pain , salicylatetoxicity (mild, early presetation).

hyperventilation syndrome (activation of sympathetic system, reduction in CO2, hypocalceamia)

activation of sympathetic system: palpitation,sweating, dry mouth, tremulousness

reduction in CO2: precordial pain, epigastric pain, light-headedness, faintness

hypocalcaemia: tinnitus, convulsions, peroral numbness and tingling, paraesthesia

smothering sensation

intense fear

Symptoms of $CO_2$ retention (Respiratory Acidosis)

Vasodilation leading to headache, red face, and confusion.

Respiratory Alkalosis causes

Panic attack, Anxiety, Lung diseases (mild, moderate), Pulmonary embolism, Hypoxemia, Fever, Pain, and early Salicylate toxicity.

Respiratory Acidosis causes

Respiratory muscle weakness (GBS, MG, MND), drug overdose (narcotics, benzodiazepines, opioids), COPD exacerbation, and severe asthma.

Hyperventilation Syndrome (Hypocalcaemia symptoms)

Tinnitus, convulsions, perioral numbness and tingling, and paraesthesia.

Salicylate toxicity progression

Causes respiratory alkalosis at the beginning and later on causes metabolic acidosis.