Hypoventilation

Causes

Hypoventilation may be caused by:

• A medical condition such as stroke affecting the brainstem
• Voluntary breath-holding or underbreathing, for example, hypoventilation training or the Buteyko method.
• Medication or drugs, typically when taken in accidental or intentional overdose. Opioids are a well-known cause of drug-induced hypoventilation due to their depressant effects on the central respiratory centers. Recent studies have highlighted patterns of postoperative opioid-induced respiratory depression that may help identify at-risk patients.
• Hypocapnia, which stimulates hypoventilation
• Obesity; see Obesity hypoventilation syndrome

• Chronic mountain sickness, a mechanism to conserve energy.

• Paralyzing venom, such as that of the blue ringed octopus.

Medications

As a side effect of medicines or recreational drugs, hypoventilation may become potentially life-threatening. Many different central nervous system (CNS) depressant drugs such as ethanol, Antihistamines, benzodiazepines, barbiturates, GHB, sedatives, and opioids produce respiratory depression when taken in large or excessive doses, or mixed with other depressants. Strong opiates (namely fentanyl, heroin, and morphine), barbiturates, and certain benzodiazepines (such as alprazolam) are known for depressing respiration. In an overdose, an individual may cease breathing entirely (go into respiratory arrest) which is rapidly fatal without treatment. Opioids, in overdose or combined with other depressants, are notorious for such fatalities. Nevertheless, appropriate use of opioids in the right setting, as seen in patients with advanced cancer or severe chronic non-malignant pain, have been shown to be helpful, when used under appropriate medical care and guidance.