Obstructive sleep apnea

Epidemiology


Etiology


Pathophysiology

Obstruction of the upper airways �?apnea �?�?partial pressure of oxygen in arterial blood (PaO2), �?partial pressure of carbon dioxide in arterial blood (PaCO2, also known as hypercapnia), which leads to:
  • �?Hypoxic pulmonary vasoconstriction �?�?pulmonary hypertension �?cor pulmonale
  • �?Sympathetic activity �?secondary hypertension
  • Respiratory acidosis �?renal compensation �?increased HCO3�?/sup> retention and decreased chloride reabsorption

    Clinical features


    Diagnostics

    Tip

    In OSA, hypercapnia is usually absent when the patient is awake. This fact explains why arterial blood gases would be mostly normal in a patient with OSA. Therefore, this test is not useful for diagnosis.


    Treatment

    Upper airway modification