What is Hypoxia?

Hypoxia is a condition where there is a decrease in the amount of oxygen reaching the body's tissues.

Causes of Hypoxia

Hypoxia can be caused by a variety of factors, including pulmonary disorders, cardiovascular disease, trauma, carbon monoxide poisoning, and drug overdose. Given the frequency of these causes in their work, firefighters must be prepared to recognize and manage hypoxia in emergency situations.

Overall, understanding the potential causes of hypoxia and being prepared to manage this potentially life-threatening condition is critical for firefighters and other first responders.

1. Respiratory emergencies:

   Conditions such as asthma, chronic obstructive pulmonary disease (COPD), and pneumonia can impair the lungs' ability to transfer oxygen to the blood, leading to hypoxia.

   Individuals with respiratory conditions may experience shortness of breath, rapid breathing, and wheezing, which can indicate a lack of oxygen in the body. These symptoms can worsen during periods of physical exertion, stress, or exposure to environmental triggers such as allergens or pollutants.

2. Cardiac emergencies:

   Cardiac emergencies are another potential cause of hypoxia in the prehospital setting. Conditions such as heart failure, heart attack, and pulmonary embolism can reduce blood flow to the body's tissues, leading to hypoxia.

   When the heart is unable to pump blood effectively, the body may not receive sufficient oxygen, resulting in hypoxia. Individuals with cardiac emergencies may experience symptoms such as chest pain, shortness of breath, and rapid or irregular heartbeat, which can indicate a lack of oxygen to the tissues.

3. Trauma:

   When an individual experiences severe trauma, such as from a motor vehicle accident or a fall, they may sustain injuries that impede their ability to breathe and deliver oxygen to their tissues.

   Injuries such as broken ribs or a collapsed lung can interfere with the normal mechanics of breathing, preventing sufficient oxygen intake. Additionally, traumatic injuries can cause significant bleeding, reducing the body's ability to transport oxygen to the tissues. In some cases, trauma can also lead to shock, which can result in decreased oxygen delivery to the tissues.

4. Carbon monoxide poisoning:

   When individuals inhale smoke from a fire, they may be exposed to high levels of carbon monoxide, a poisonous gas that can cause hypoxia by binding to the hemoglobin in the blood, reducing the amount of oxygen that can be carried to the body's tissues.

   A complication with carbon monoxide poisoning is that it can lead to a false readings when using an SpO2 monitor. This is because carbon monoxide can bind to hemoglobin in a similar way to oxygen, which can cause the SpO2 monitor to read a normal oxygen saturation level, such as 99%. However, even if the SpO2 reading appears normal, the individual may still be experiencing hypoxia due to carbon monoxide poisoning.

   Therefore, it's important to always administer high-flow oxygen to any fire patient, including those who have potentially been exposed to carbon monoxide. Providing high-flow oxygen can help to displace carbon monoxide from hemoglobin and increase the amount of oxygen available to the body's tissues.

5. Drug overdose:

   Many drugs, particularly opioids and sedatives, can cause respiratory depression, which means that an individual's breathing rate is reduced and they may not receive enough oxygen.

Symptoms of Hypoxia

The symptoms of hypoxia can vary depending on the severity of the condition and the underlying cause. Some common symptoms of hypoxia include shortness of breath, rapid or shallow laboured breathing, cyanosis (bluish tint to the skin), confusion or disorientation, headache, fatigue, nausea, rapid heartbeat, and dizziness or lightheadedness.

How to Check for Hypoxia Using an SpO2 Monitor

As an advanced first aider who is allowed to treat with oxygen, it's important to understand how to check for hypoxia using an SpO2 monitor. An SpO2 monitor measures the oxygen saturation in the blood, which can help determine if an individual is experiencing hypoxia.

To use an SpO2 monitor, follow these steps:

1. Turn on the monitor and place the sensor on the individual's fingertip.

2. Wait for the monitor to display the oxygen saturation percentage.

3. Take note of the percentage and compare it to normal levels.

What Percentage of Oxygen on the Monitor Indicates Different Severities of Hypoxia?

Normal oxygen saturation levels are typically between 95-100%. If the oxygen saturation level is below 95%, it may indicate hypoxia. The severity of hypoxia can be determined by the following percentage ranges:

1. Mild hypoxia: Oxygen saturation level between 90-94%.

2. Moderate hypoxia: Oxygen saturation level between 80-89%.

3. Severe hypoxia: Oxygen saturation level below 80%.

It's important to note that an SpO2 monitor is not a definitive diagnosis of hypoxia and should be used in conjunction with other symptoms and clinical assessments.

Treatment of Hypoxia

As an advanced first aider who is allowed to treat with oxygen, your first step in treating hypoxia is to administer high flow O2 via NRB (Non Rebreather) or BVM (Bag Valve Mask).

Administering supplemental oxygen is a key treatment measure for hypoxia, but it's also important to address the underlying condition that is causing the hypoxia. This may involve working closely with other healthcare providers, such as respiratory therapists or emergency medical services personnel, to provide comprehensive care.

Overall, as an advanced firefighter, being familiar with the causes, symptoms, treatment, and prevention of hypoxia can help you provide effective care and support to individuals who are experiencing this potentially life-threatening condition.