QS Study

Hypercapnia means excess Carbon Dioxide (CO2) in the fluid. It generally triggers a reflex which increases breathing and entrance to oxygen (O2), such as arousal and turning the head during sleep. A failure of this reflex can be fatal, for example as a contributory factor in sudden infant death syndrome. It can also be a symptom of underlying conditions that affect your breathing and your blood.

Cause: Usually occurs in association with hypoxia only when the hypoxia is caused by hypoventilation or circulatory deficiency. There are a number of causes, including seizures, drug overdoses, lesions on the brainstem, lung disease, hyperventilation, skeletal muscle weakness, asthma, chronic obstructive pulmonary disease, and sleep apnea.

Severe hypercapnia symptoms include: confusion, coma, depression or paranoia, excessive breathing, irregular heartbeat, muscle twitching etc.

Effects of hypercapnia

(a) Stimulates respiration,

(b) Produces symptom due to depression of central nervous system,

  • Contusion
  • Diminish sensory acuity and eventually coma
  • Respiratory depression and death.
  • Respiratory acidosis
  • Raising of plasma HCO3 to compensate acidosis.

(c) Stimulation of ventilation via both central and peripheral chemoreceptors

(d) Cerebral vasodilation increasing cerebral blood flow and intracranial pressure

(e) Stimulation of the sympathetic nervous system resulting in tachycardia, peripheral vasoconstriction, and sweating.