Search results
Results from the WOW.Com Content Network
Carbon dioxide molecule.. pCO 2, pCO 2, or is the partial pressure of carbon dioxide (CO 2), often used in reference to blood but also used in meteorology, climate science, oceanography, and limnology to describe the fractional pressure of CO 2 as a function of its concentration in gas or dissolved phases.
The alveolar oxygen partial pressure is lower than the atmospheric O 2 partial pressure for two reasons.. Firstly, as the air enters the lungs, it is humidified by the upper airway and thus the partial pressure of water vapour (47 mmHg) reduces the oxygen partial pressure to about 150 mmHg.
P a O 2 – Partial pressure of oxygen at sea level (160 mmHg in the atmosphere, 21% of standard atmospheric pressure of 760 mmHg) in arterial blood is between 75 mmHg and 100 mmHg. [4] [5] [6] Venous blood oxygen tension (normal) P v O 2 – Oxygen tension in venous blood at sea level is between 30 mmHg and 40 mmHg. [6] [7]
The values of pH and HCO3 of venous blood are close enough to arterial blood for direct comparison. The pCO2 of venous blood is less reliably compared to arterial blood but may be used in some cases. The PO2 level of venous blood is always significantly lower that arterial and should be reported, labeled and interpreted as venous PO2. [21]
Acute respiratory acidosis occurs when an abrupt failure of ventilation occurs. This failure in ventilation may be caused by depression of the central respiratory center by cerebral disease or drugs, inability to ventilate adequately due to neuromuscular disease (e.g., myasthenia gravis, amyotrophic lateral sclerosis, Guillain–Barré syndrome, muscular dystrophy), or airway obstruction ...
Hypercapnia (from the Greek hyper, "above" or "too much" and kapnos, "smoke"), also known as hypercarbia and CO 2 retention, is a condition of abnormally elevated carbon dioxide (CO 2) levels in the blood. Carbon dioxide is a gaseous product of the body's metabolism and is normally expelled through the lungs.
Blood levels of oxygen become important in hypoxia. These levels are sensed by central chemoreceptors on the surface of the medulla oblongata for decreased pH (indirectly from the increase of carbon dioxide in cerebrospinal fluid ), and the peripheral chemoreceptors in the arterial blood for oxygen and carbon dioxide.
Respiratory failure is classified as either Type 1 or Type 2, based on whether there is a high carbon dioxide level, and can be acute or chronic. In clinical trials, the definition of respiratory failure usually includes increased respiratory rate , abnormal blood gases (hypoxemia, hypercapnia, or both), and evidence of increased work of breathing.