Acidosis and Alkalosis

You can read my post about ABGs here.

Respiratory Acidosis

Respiratory acidosis is caused by poor alveolar ventilation. This leads to the retention of CO². Causes can include asthma, respiratory depression and COPD.

An ABG would show:

ph level


Respiratory Alkalosis

Respiratory alkalosis is caused by excessive alveolar ventilation, also known as hyperventilation. This causes more CO² to be exhaled than usual. PaCO² is reduced, causing the ph level to increase. Causes can include anxiety (panic attack), pulmonary embolism and pneumophorax.

An ABG would show:

ph level


Metabolic Acidosis 

Metabolic acidosis can occur due to increased acid production or decreased acid excretion. Can be caused by things such as diabetic ketoacidosis and Addison’s disease.

Metabolic Alkalosis

Metabolic alkalosis occurs due to a decreased hydrogen ion concentration. This leads to a rise in bicarbonate. Can also occur directly due to an increased bicarbonate concentration. Causes can include vomiting/diarrhoea (gi loss of H+ ions) and heart failure or cirrhosis (renal loss of H+ ions).

Below is what an ABG would show for metabolic acidosis and alkalosis:




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One thought on “Acidosis and Alkalosis

  1. Pingback: A guide to ABGs | Student Nurse and Beyond

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