Introduction

The brain relies on the blood to provide it with a continual supply of oxygen, thus, any interruptions to any portion of the body that affects blood or oxygen flow might result in hypoxia.

So, how long can a person survive oxygen deprivation?

Deep sea divers who practice some forms of meditation, as well as a number of other exceptions to the rule, may be able to endure extended amounts of time without oxygen. For the average person, oxygen deprivation poses an imminent threat. The timeline from initial hypoxia to brain damage, for example, varies with the degree of oxygen deprivation. Minor oxygen deprivation only causes harm over an extended period, whereas serious hypoxia causes near-instant damage. Brain injury can occur within a minute or two of total oxygen deprivation. Death of brain cells and the catastrophic brain damage cause the majority of individuals to die within 10 minutes of total oxygen deprivation.. Those in poor health often die much sooner; some people may suffer other medical catastrophes, such as heart attacks in response to oxygen deprivation.¹

Understanding hypoxia

During a severe asthma episode or flare, children and adults may experience low oxygen levels. The airways narrow, making it difficult to get air into the lungs. Coughing can make the symptoms worse, as clearing the lungs uses even more oxygen. Low oxygen levels can also result from lung damage due to trauma, also causing high lung diseases such as emphysema, chronic obstructive pulmonary disease, bronchitis, pulmonary edema or fluid in the lungs and pneumonia. Heart problems, strong medications for pain and other drugs that hold back breathing, anemia and poisoning are some signs and symptoms of hypoxia.²

1. Shortness of breath is the most common sign and symptom of your body's not getting enough oxygen. Sometimes, you may experience shortness of breath, which means you need to take in more air to absorb more oxygen 
2. Yawning may additionally be triggered by shallow breathing or shortness of breath, both of which suggest an inadequate supply of oxygen
3. A lack of energy could be another sign that you are low on oxygen. A combination of exercise and breathing activities can address the issue
4. Shallow breathing, dizziness, and a sense of euphoria are two signs that the body is not getting enough oxygen. Before passing out or fainting, people frequently feel dizzy, which is often caused by a lack of oxygen
5. Elevated blood pressure 
6. When the brain lacks oxygen, it will result in confusion and an inability to follow instructions
7. Anxiety and stress. Some of these signs and symptoms may not be enough to conclude low oxygen levels in the body. However, two or three symptoms at a time will indicate a serious health condition. The dangers of low oxygen levels in the body, or hypoxia, causes decreased oxygenation of multiple organs in the body such as the brain, kidneys, liver and more. Having low oxygen levels damages these organs and ultimately leads to organ failure and even death. Moreover, hypoxia during pregnancy may also result in foetal death. If hypoxia is identified and treated early, patients can fully recover without any complications⁴

Symptoms and clinical presentation

People experiencing hypoxia may feel like they can't breathe, struggle to catch their breath or experience a rapid heart rate as the heart beats faster to attempt to supply the brain with blood. Symptoms include obstructing the face, mouth or nose. Increased carbon monoxide exposure can be a problem in enclosed areas, so a person in a very small space whose face is covered may suffer from oxygen deprivation. The victim may seem confused or experience a loss of consciousness, fainting, seizures, blue or white lips, tongue or face tingling in the extremities, pupils that don't respond normally to light, not breathing or not expelling air when exhaling, hyperventilation or gasping for air. Numerous illnesses and injuries can cause hypoxia. These include traveling to high altitudes, especially for people in poor health and for those who quickly rise to high altitudes. Carbon monoxide poisoning, strangulation or smothering can also cause hypoxia. Very low blood pressure, usually caused by something else such as a hemorrhage, smoke inhalation, choking, heart attack or stroke, can result in hypoxia. Medical conditions such as heart attack or strobe allergic reactions that lead to anaphylactic shock can also lead to oxygen deprivation. Severe cases of asthma allergies hyperventilation and, in infants, improper sleep positions or unsafe sleep environments can lead to an inadequate oxygen supply in children or babies especially whilst they are sleeping on their stomachs.⁶

Diagnostic approaches

Common diagnostic approaches to diagnosing hypoxia include:

Clinical Diagnosis

• Vital Signs: Respiratory Rate, Heart Rate, Blood Pressure, 
• Neurological Signs: Anxiety, confusion, restlessness, and level of consciousness (unresponsive, arousable, and awake)
• Signs of cyanosis: These manifest when 15% or 2-3 gm of haemoglobin is desaturated
• Circulation: Capillary refill, perfusion status

Non-Invasive Monitoring

• Pulse Oximetry (SpO₂)
• Capnography (EtCO₂)
• Airway pressure monitor⁷

Imaging & Lab Tests

• Chest X-ray, CT Scan
• Arterial Blood Gas (ABG)

Treatment strategies

Treating hypoxia has major goals, such as maintaining airway function and increasing the amount of oxygen inherited. The common treatments include:

• Suctioning in the upper airways to keep them clear and remove foreign objects, reducing any blockage in the throat, such as by treating the head
• Using ventilation devices such as a continuous positive airway pressure machine
• Using bronchodilator medications, which help expand the airways
• Chest physiotherapy 
• Endotracheal tube
• Having a flutter valve to help keep the airways clear of mucus 
• Using an incentive spiral spirometer to help a person visualise their bleeding and learn to take slow, deeper breaths 
• Use of nasal cannulas to supply oxygen through the nostril
• Using a face mask to supply oxygen to the nose and mouth
• Diuretics are used to remove extra fluid in persons with edema
• Steroids are used for some persons with interstitial lung disease

It is essential to contact a doctor and speak with them regarding any sudden symptoms such as troubled breathing, very rapid heart rate, discolored skin, or altered levels of consciousness. 

Conclusion

Hypoxia is the reduced delivery of oxygen to the tissues, enzymes or the vitality of the tissue and enzymes. For the average person, oxygen deprivation poses an imminent threat. The timeline from initial hypoxia to depth or brain damage varies with the degree of oxygen deprivation. It is essential that medical care is sought immediately.

FAQs

What is the difference between hypoxia and hypoxemia?

Hypoxia occurs when there is insufficient oxygen in the blood. In some circumstances, hypoxemia can result in hypoxia because the blood does not contain enough oxygen to supply the required amount to the cells or tissues.

How to prevent hypoxia?

Maintaining a healthy diet and staying active are crucial. To prevent flare-ups, make sure that medication is administered on time.