Difference Between Asphyxia and Hypoxia

Main Difference – Asphyxia vs Hypoxia

Asphyxia and Hypoxia are two terms used in physiology to refer an insufficient supply of oxygen to cells and tissues. Even though the fundamental mechanism of these two conditions differs a lot from each other, most people find it bit confusing to identify one from the other due to the lack of knowledge. The main difference between Asphyxia and hypoxia is that asphyxia is caused by an injury or obstruction of airway passages whereas hypoxia is caused by inadequate delivery, uptake or utilization of oxygen by the body’s tissues

This article explains,

1.What is Asphyxia?
– Definition, Causes, Signs and Symptoms, and Management

2.What is Hypoxia?
– Definition, Causes, Signs and Symptoms, Management and Prevention

3. What is the difference between Asphyxia and Hypoxia?

What is Asphyxia

Asphyxia is defined as a multi-etiologic set of ailments in which there is an inadequate delivery, uptake or utilization of oxygen by the body’s tissues, often accompanied by carbon dioxide retention. This term is derived from an ancient Greek word, meaning α/A- “without” and asphyxia, meaning “squeeze” or “stopping of the pulse.”

Being a severe condition caused by a deficiency in supplying oxygen to tissues due to an abnormal breathing, Asphyxia usually occurs as a result of an obstruction or constriction in the airway canal. This obstruction can be caused due to a foreign body, inability to gain oxygen, which is richly available in the external environment, due to a potent contamination by smoke or fumes and poorly oxygenated environments like underwater or vacuum.

Commonest situations which are known to result in asphyxia include, asthma, chronic obstructive pulmonary disease, Laryngospasms, choking, foreign objects, acute respiratory distress syndrome, carbon monoxide inhalation, drowning, hanging, strangulation, overdose of drugs, sleep apnea, inert gas asphyxiation, etc.

Signs and symptoms associated with this condition mainly include difficulty in breathing, stridor, rapid pulse (tachycardia), hypertension, facial cyanosis, swollen and engorged veins on head and neck, seizures, paralysis, loss of consciousness, coma, and death.

It is highly important to attend to this condition as a medical emergency; if untreated on time, it can readily result in coma or death.

The major management of asphyxia depends on the etiology.

Choking due to obstructed foreign bodies – Remove the material using Heimlich maneuver
Drowning – Safe removal of the victim from the water.
Gas poisoning – Take the victim and let him breath fresh air. Evacuate other people in the same establishment.
Suffocation – Loosen clothes, remove causative material e.g. Polythene bags
Strangulation – Remove the object used to strangle as soon as possible.
Asthma attack – Assess the airway, breathing, and circulation which will be followed by medication.

In general, all patients with Asphyxia should be given cardiopulmonary resuscitation whenever the condition is severe and life threatening.

What is Hypoxia

Hypoxia is defined as a condition where body tissues are not adequately oxygenated. This condition is mostly due to an insufficient concentration of oxygen in the blood.

This will ultimately result in an impairment of the metabolic activities taking place in the body, giving rise to several compensatory signs and symptoms as follows.

An increase in the heart rate, myocardial contractility, and cardiac output.
Shortness of breath, wheezing
Sweating
Cyanosis or bluish discoloration of mucosal membranes due to poor peripheral blood supply.
Other changes of the skin color, ranging from blue to cherry red depending on the etiology.

Hypoxia can be categorized as

Local – affecting a specific area of the body
Generalized – Involving the whole body which may be sometimes referred to as Anoxia (a complete deprivation of oxygen-rich blood supply, throughout the body.

Causes of Hypoxia

Hypoxia can be caused by several different conditions such as,

Anaemia, which is a condition caused by a reduced amount of functional hemoglobin, reducing the oxygen-carrying capacity of blood,
Heart diseases and lung diseases such as COPD, Emphysema, Bronchitis, Pulmonary edema
Carbon monoxide poisoning – This gas which has a higher potential of getting attached to hemoglobin when compared to that of oxygen can give rise to heart failure, cardiac arrest or myocardial infarction.

Hypoxia isn’t necessarily found in ill people but can be seen in completely healthy people living in high altitudes due to a lowered partial pressure of oxygen in inhaled air. This specific condition can be very severe and life threatening, and can result in complications including high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE).

How to Prevent Hypoxia

Depending on the etiology, this may vary from avoiding triggering factors (like in asthma) to proper medication or surgical interventions.

Keep your Asthma under control by being compliant on drugs.
Good physical exercise and healthy diet
Get treatment for underlying conditions such as cardiac diseases, lung diseases, and Anemia.
Be aware of hypoxic signs and symptoms in order to get timely medical advice in case.

Asphyxia is a deprivation of oxygen at the tissue levels due to an injury or obstruction of airway passages such as in strangulation, aspiration of food (choking), near-drowning, drowning etc.

Hypoxia is a condition characterized by an inadequate supply of oxygen in the blood due to reduction of partial pressure of oxygen, inadequate oxygen transportation and inability of the body tissues to use oxygen due to some pathology.

Both these conditions can be treated in the same manner by ensuring airway, breathing and circulation (A, B, C) where specific management can be done by addressing the individual causative agents.

Image Courtesy:

“Asthma inhaler use” By United States National Institute of Health: Heart, Lung and Blood Institute (Public Domain) via Commons Wikimedia

“Obstruction ventilation apnée sommeil” By English: Credits to Habib M’henni / Wikimedia Commons – Own work based on: http://topnews.in/health/files/sleep-apnea_0.jpg (Public Domain) via Commons Wikimedia