Symptoms of hypercapnia
Main symptoms of carbon dioxide toxicity, by increasing volume percent in air.[1][2]
SpecialtyPulmonology, critical care medicine

Hypercapnia (from the Greek hyper = "above" or "too much" and kapnos = "smoke"), also known as hypercarbia and CO2 retention, is a condition of abnormally elevated carbon dioxide (CO2) levels in the blood. Carbon dioxide is a gaseous product of the body's metabolism and is normally expelled through the lungs. Carbon dioxide may accumulate in any condition that causes hypoventilation, a reduction of alveolar ventilation (the clearance of air from the small sacs of the lung where gas exchange takes place). Inability of the lungs to clear carbon dioxide leads to respiratory acidosis. Eventually the body compensates for the raised acidity by retaining alkali in the kidneys, a process known as "metabolic compensation".

Acute hypercapnia is called acute hypercapnic respiratory failure (AHRF) and is a medical emergency as it generally occurs in the context of acute illness. Chronic hypercapnia, where metabolic compensation is usually present, may cause symptoms but is not generally an emergency. Depending on the scenario both forms of hypercapnia may be treated with medication, with mask-based non-invasive ventilation or with mechanical ventilation.

Signs and symptoms

Hypercapnia usually happens in the context of an underlying health condition, and symptoms may relate to this condition or directly to the hypercapnia. Specific symptoms attributable to early hypercapnia are dyspnea (breathlessness), headache, confusion and lethargy. Clinical signs include flushed skin, full pulse (bounding pulse), rapid breathing, premature heart beats, muscle twitches, and hand flaps (asterixis). The risk of dangerous irregularities of the heart beat is increased.[3][4]

In severe hypercapnia (generally PaCO2 greater than 10 kPa or 75 mmHg), symptomatology progresses to disorientation, panic, hyperventilation, convulsions, unconsciousness, and eventually death.[5][6]

Other Languages
беларуская: Гіперкапнія
bosanski: Hiperkapnija
català: Hipercàpnia
Deutsch: Hyperkapnie
español: Hipercapnia
Esperanto: Hiperkapnio
français: Hypercapnie
Bahasa Indonesia: Hiperkapnia
italiano: Ipercapnia
norsk: Hyperkapni
polski: Hiperkapnia
português: Hipercapnia
русский: Гиперкапния
српски / srpski: Хиперкапнија
srpskohrvatski / српскохрватски: Hiperkapnija
svenska: Hyperkapni
Türkçe: Hiperkapni
українська: Гіперкапнія
Tiếng Việt: Tăng CO2 máu