Management of Hypoxia in Older Aged People- An Overview

Introduction:

The brain mainly depends upon the blood to provide it with a continuous supply of oxygen; thus, disruption in any part of the body that has a role in the supply of oxygen or blood can lead to hypoxia. Numerous illnesses and injuries can cause hypoxia, including traveling to higher altitudes, which is difficult for people in poor health. Other reasons like carbon monoxide poisoning, low blood pressure, strangulation or smothering, medical conditions like a heart attack or stroke, allergic reactions that may lead to anaphylactic shock, hyperventilation, and severe cases of asthma.

What Causes Hypoxia?

The four primary causes of hypoxia are-

1. No Blood Supply to the Brain - This occurs when the blood vessels that are responsible for supplying the brain with blood are completely obstructed, which is extremely rare and usually fatal.

2. Low Blood Supply to the Brain - This can occur when even a single vessel is partially obstructed or completely blocked, which commonly happens with a stroke. This type of hypoxia most often affects a specific brain region, interfering with the function governed by that area.

3. No Blood Oxygen to the Brain - When the body cannot take oxygen or the heart or lungs cannot properly provide the blood with oxygen, the brain, and all other organs suffer from hypoxia which becomes quickly fatal.

4. Low Blood Oxygen to the Brain - When the body cannot properly oxygenate the blood, often due to illness such as emphysema (lung condition causing difficulty breathing) or a condition such as a heart attack, in this case, the brain gets less oxygen than it needs to function properly.

What Are the Types of Hypoxia?

There are mainly four types of hypoxia-

1. Hypoxemic Hypoxia - It is also referred to as hypoxemia and is caused by an alteration in the ventilation for fusion coupling, certain types of pulmonary diseases, and in the atmosphere with low oxygen, like high altitudes.

2. Anemic Hypoxia - It occurs due to a decrease in hemoglobin or the absence of red blood cells (RBC) due to vitamin B12 deficiency, iron deficiency, or hemolytic anemia.

3. Ischemic Hypoxia - This occurs due to a decrease in blood volume as a result of congestive heart failure or obstruction due to thrombosis (blood clots that block arteries or veins).

4. Histotoxic Hypoxia - This results from tissue damage that cannot absorb oxygen due to certain conditions like cyanide poisoning.

What Are the Signs and Symptoms Seen in Hypoxia?

Several signs and symptoms that can be seen are-

• Agitation.

• Shortness of breath.

• Cyanosis

• Confusion.

• Unconsciousness.

• Seizures.

• Increased respiratory rate.

• Changes in skin color.

• Sweating.

• Chest pain.

• Headache.

• Visual disorders.

How Long A Person Can Survive Oxygen Deprivation?

Deep sea divers or people who practice a certain form of meditation may be able to survive longer periods than an average person without oxygen. For the average person, oxygen deprivation can pose an imminent threat, and the timeline for initial hypoxia to brain damage or death varies with the degree of oxygen deprivation. Minor oxygen deprivation can only cause damage with time, but true hypoxia can trigger near-instant damage. Brain damage can start within a minute or two, and then the death of the brain cells and severe brain damage that accompanies it becomes inevitable. Most people can die within 10 minutes of total oxygen deprivation, and those in poor health will die much sooner. Some people may suffer from other medical catastrophes, such as heart attacks, in response to oxygen deprivation.

How to Diagnose Hypoxia?

The partial pressure of oxygen is referred to as PO2. Normally it is between 11 and 13 kilopascals in a healthy individual.

• Pulse oximetry, or an SAT (oxygen saturation) probe, is a non-invasive and quick test that measures the amount of oxygenated hemoglobin in arterial blood and displays it as a percentage. Normal oxygen saturation in a healthy patient is around 95 % and above. In patients with chronic respiratory disorders baseline, oxygen saturation may show lower values of 90 %.

• Additionally, measuring the partial pressure of oxygen in the blood can be done by taking a sample from the artery and running it through an arterial blood gas machine. This device also measures carbon dioxide, serum PH, and serum bicarbonate which gives further information about the patient’s current metabolic and respiratory function.

• Computerized tomography (CT scan), magnetic resonance imaging (MRI), and brain imaging are also performed to diagnose hypoxia.

How Is Hypoxia Treated?

The primary goal is to find the cause of hypoxia and make a treatment plan accordingly.

• After the diagnosis, the first action is to give supplemental oxygen. 15 liters of oxygen per minute through a non-rebreather face mask is usually the best option. This also allows further assessments of the patient and treatment of the underlying cause of hypoxia.

• Making the patient sit upright also helps them to oxygenate, improving their respiratory volumes and lung mechanics.

• In some patients, prolonged high concentrations of oxygen therapy might be avoided, like in patients with chronic obstructive airway disease, depending on the degree of hypoxia to provide their drive to breathe; in this certain condition, the hypoxia is treated first, and then the oxygen concentration is titrated downwards until the normal oxygen saturation is achieved.

• In case of severe respiratory failure, admitting the patient to the intensive care unit for non-invasive or invasive ventilation may be required.

How to Manage Hypoxia in Elderly People?

Hypoxia plays a major role in developing age-related neurological disorders such as Alzheimer's and Parkinson's disease and also contributes to the decline of the physiological functioning of the elderly person. After a proper assessment of hypoxia, the following things should be done-

• If the hypoxia is mild, then deep breathing exercises can be taught, and the elderly should be asked to consume plenty of water.

• If any medical condition causes hypoxia, the patient should be rushed to the hospital.

• The first criterion is to maintain the oxygen levels in the patient and then achieve a normal heartbeat.

• Oxygen therapy is one of the methods that can be administered in elderly patients with low levels of oxygen.

• Older people can also benefit from rehabilitation programs after recovering from the hypoxic encounter.

• Regular blood oxygen monitoring should be done.

• A well-maintained diet and regular exercise are the key factors to healthy living.

• An elderly person who smokes cigarettes should quit as soon as possible.

Conclusion:

The older population is at greater risk of mortality due to hypoxia in comparison with younger individuals, as they are also associated with other conditions such as frailty, hypertension, and cardiovascular diseases. It is important to remember that hypoxia is not a permanent condition, but if any person suffers from it, it is advisable to seek medical attention to avoid further damage.