Hypercarbia

What is Hypercarbia?

Hypercarbia is a condition caused by too much carbon dioxide in your blood. There are many reasons why this can happen, but our bodies are typically able to balance things out if the breathing mechanisms and lung functions are working properly. However, if the body can’t compensate adequately, this can lead to a condition called respiratory acidosis. Many people with chronic hypercarbia, due to lung disease, and normal kidney function will keep more bicarbonate in their bodies to keep a stable pH balance. Hypercarbia is also commonly referred to as hypercapnia.

What Causes Hypercarbia?

Hypercarbia refers to having too much carbon dioxide (CO2) in your blood. Several factors can cause this.

Firstly, you might be breathing out too little CO2 because of hypoventilation. Hypoventilation means you’re not getting enough air in and out of your lungs. This could be due to a sluggish response from your brain signaling the need to breathe (CNS depression), weak respiratory muscles, or a mismatch between air flow and blood flow in your lungs. These causes can occur individually or together.

Secondly, your body might be making too much CO2 and not breathing out enough to compensate for it. CO2 is a waste product that your body needs to remove during breathing. Various factors can speed up its production like fever, metabolic acidosis, a severe infection called sepsis, thyroid disease, and others. These conditions can overwhelm the body’s ability to remove excess CO2. It’s particularly hazardous for patients with existing lung or brain disorders. Eating a lot of carbohydrates can sometimes cause hypercarbia in people with impaired lung function as well.

Thirdly, you could inhale too much CO2 in the environment, which can happen during some surgical procedures when CO2 is used to inflate body cavities. Although generally safe, this can lead to hypercarbia and related circulatory problems. If you’re in a confined space with poor air circulation where CO2 is enriched, you could also end up with hypercarbia.

Lastly, chronic hypercarbia can happen if you have a lung disease. This is often a slow process where the lungs gradually become less effective at removing CO2. Your kidneys usually compensate for this by increasing bicarbonate in your blood, which helps maintain a normal pH level despite the elevated CO2.

Risk Factors and Frequency for Hypercarbia

Hyercarbia, a type of acid-base disturbance, is not regularly recorded. It is most often used to assess and track an existing disease.

Signs and Symptoms of Hypercarbia

Hypercarbia, which refers to increased levels of carbon dioxide in the blood, can appear suddenly (acute) or over time (chronic). Depending on how quickly or slowly it develops, hypercarbia can cause different symptoms.

Possible symptoms for a quick onset of hypercarbia can include trouble breathing, tiredness, confusion leading to drowsiness, headaches, flushed skin, and feeling sick. If hypercarbia develops over a longer period, symptoms can include tiredness, irritability, headaches, and difficulty breathing, particularly when exercising.

It’s crucial to have a medical history check to understand better your condition, including any relevant details about your health in the past, lifestyle habits, and any medication you’re taking.

The symptoms you feel might differ, as hypercarbia affects everyone a little differently. You might have a slower or more shallow breathing pattern, have to use extra muscles to breathe, feel unusually tired, sweat excessively, have a fever, or experience wheezing. People with low oxygen levels are often also dealing with hypercarbia, so there can be some symptom overlap. It’s also essential to consider hypercarbia in patients who have low oxygen levels according to pulse oximetry equipment.

If you have overdosed on drugs, symptoms of hypercarbia might also be accompanied by other signs of illicit drug use or a heart murmur. If you have a chronic lung disease, you might also hear wheezing or rattle-like sounds in your lungs. Doctors also need to check if you’ve been receiving too much supplemental oxygen (above 94% saturation). Too much supplemental oxygen can cause oxygen-induced hypercarbia.

Testing for Hypercarbia

To know whether someone has hypercarbia, which is an excess of carbon dioxide (CO2) in the blood, testing the blood gasses is needed. Blood can be taken from a vein or an artery, but an artery is typically used, even though it’s more uncomfortable, because the CO2 levels there are more accurate. If the CO2 level is over 45 mmHg, it suggests hypercarbia.

When the same blood sample’s pH is checked and it’s within the normal range, it might mean that the hypercarbia has been there for a long time, or that there’s another condition affecting the body’s acid-base balance. If the pH is less than 7.35, it’s called respiratory acidosis, which means the body isn’t removing CO2 well enough.

The next step depends on the patient’s history and physical exam signs. Another blood test called a basic metabolic panel can help the doctor check for other health issues that might relate to hypercarbia. If the doctor suspects an overdose, a urine drug test may be ordered. If there’s a chance of an infection causing fever, then blood and sputum (mucus) tests, and imaging of the chest will be required. The function of the thyroid gland, which regulates the body’s metabolism, also needs to be checked because certain thyroid diseases can contribute to hypercarbia.

Head imaging may be performed, too, as a stroke might cause the nervous system to become sluggish, leading to slow, shallow breathing. Although not commonly used in an emergency, tests of lung function could be helpful in diagnosing lung disease or subtle changes in lung function due to nerve and muscle diseases like amyotrophic lateral sclerosis. If the doctor suspects that a sleep disorder related to breathing, like obesity hypoventilation syndrome, may be causing the problem, an overnight sleep study could be ordered. This study records brain waves, blood oxygen levels, heart rate, and respiratory rate during sleep.

Treatment Options for Hypercarbia

Hypercarbia is a condition where there is too much carbon dioxide (CO2) in the blood, typically caused by inadequate ventilation or the body not breathing enough. The best way to treat this condition is to help the patient breathe better, which often starts while figuring out what is causing the issue.

For patients who can still breathe, the first option is usually a treatment called non-invasive positive pressure ventilation. It helps patients breathe in a steady stream of air, usually delivered via a full face mask. Ideally, better ventilation should lead to a decrease in CO2 levels within a few minutes or hours.

If the non-invasive method doesn’t improve the situation, the patient can’t breathe independently, or the non-invasive method is not appropriate, the next step is to use a machine to help the patient breathe. This is called mechanical ventilation or intubation. Once the patient’s breathing is supported in this way, doctors can focus on addressing the underlying issue causing the problem. This could include lung disease, the misuse of drugs or medication, a weakened nervous system, or other health conditions. As the patient’s CO2 levels become more normal, they often become more alert and can gradually start to breathe independently again.

In general, patients connected to a ventilator should see their CO2 levels normalize within hours, except for patients with severe lung diseases. In these cases, such as with severe pneumonia, asthma attack, or a condition called Acute Respiratory Distress Syndrome (ARDS), it might take days to gradually reduce CO2 levels. In some situations, immediately or completely normalizing CO2 might not be the goal. This is often seen in the treatment of ARDS, where a lower amount of air flow is permitted to prevent further damage to the lungs. This results in higher CO2 levels but it’s usually tolerated as long as it doesn’t result in extremely low pH levels (which measures the acidity of blood).

Similarly, in severe asthma attacks, doctors may maintain a higher level of CO2 to prevent the buildup of air in the lungs due to insufficient exhalation, which could exacerbate breathing difficulties and other issues. While treating the asthma with medications, a lower respiratory rate is set on the ventilator, causing an increase in CO2 but improving air flow.

In situations where hypercarbia is severe and the above treatments are not effective or suitable, there is an alternate course of action called extracorporeal carbon dioxide removal (ECCO2R). However, this method is not widely available and involves removing CO2 directly from the blood.

Some health providers, noticing the increased acidity of the blood caused by hypercarbia, might want to give the patient an alkali or basic therapy to normalize the pH. However, this approach can lead to an increase in CO2 levels and can actually make the condition worse.

Hypercarbia, a condition where there’s too much carbon dioxide (CO2) in your blood, could be caused by various health conditions both long-term (chronic) and short-term (acute). These potential causes include but are not limited to:

Chronic and Acute obstructive pulmonary disease, conditions that block airflow from the lungs
Chronic and Acute restrictive lung disease, conditions that limit the expansion of the lungs
Chronic and Acute types of kidney failure
Specific medications being administered
Interstitial lung disease, which affects the area and tissues around the lungs
Pulmonary edema, where there is an excess of fluid in the lungs
Acute respiratory distress syndrome, a severe lung condition that leads to low oxygen in the blood
Sepsis, an extreme reaction to an infection
A diet that is high in carbohydrates
Injury to the central nervous system, which consists of the brain and spinal cord
Exposure to extra CO2 during certain surgical procedures like laparoscopy, thoracoscopy, or endoscopy
Cancer, or malignancy
Neuromuscular disorders, disorders that disrupt the function of muscles or the nerves that control them
Obstructive or central sleep apnea, sleep disorders where breathing briefly and repeatedly stops
Thyrotoxicosis or myxedema coma, severe complications of thyroid diseases

What to expect with Hypercarbia

The outcome for hypercarbia, which is a condition characterized by an excess of carbon dioxide in the blood, varies and is heavily influenced by the root cause. If the cause behind acute hypercarbia, or a short-term increase in blood carbon dioxide levels, is identified quickly and treated, then the chances of recovery are good.

However, in the case of patients suffering from chronic obstructive pulmonary disease (COPD), a type of lung disease characterized by long-term breathing problems and poor airflow, and persistent (chronic) hypercarbia, the mortality rate is higher compared to those with COPD but without persistently high levels of carbon dioxide in their blood.

Possible Complications When Diagnosed with Hypercarbia

Hypercarbia, or having too much carbon dioxide in your body, can have harmful effects. These include:

Falling into a coma or becoming unconscious
Feeling confused, depressed, or paranoid
Experiencing panic attacks
Having irregular heart rhythm, also known as arrhythmias
Possibility of cardiovascular system failure, also referred as cardiovascular collapse

Preventing Hypercarbia

Patients should be informed if they have been diagnosed with hypercarbia, a condition where there’s too much carbon dioxide (CO2) in their blood. They should also be made aware of the symptoms that might indicate the condition is recurring, and advised on when to seek medical help in the future. In these cases, follow-up appointments will be scheduled with a specialist who is suitable for their condition. For instance, they may see a neurologist if they previously had a stroke, a lung specialist (pulmonologist) for lung diseases, or a psychiatrist for issues of substance abuse.

For those with severe lung disease causing hypercarbia, a re-test of the blood gases may be conducted after they’ve recovered from their immediate illness. If the levels of CO2 in their blood are still high, the use of a non-invasive positive pressure ventilation device might be suggested. This device assists in breathing and is used at home during the night. It’s also important for these patients to understand that their risk of death is higher compared to patients with chronic lung disease who do not have hypercarbia.

Frequently asked questions

Hypercarbia is a condition caused by too much carbon dioxide in the blood.

Hypercarbia is not regularly recorded, but it is used to assess and track an existing disease.

Signs and symptoms of Hypercarbia include: - Trouble breathing - Tiredness - Confusion leading to drowsiness - Headaches - Flushed skin - Feeling sick - Irritability - Difficulty breathing, particularly when exercising - Slower or more shallow breathing pattern - Using extra muscles to breathe - Unusual tiredness - Excessive sweating - Fever - Wheezing - Low oxygen levels - Symptom overlap with low oxygen levels - Accompanying signs of illicit drug use or a heart murmur in cases of drug overdose - Wheezing or rattle-like sounds in the lungs in cases of chronic lung disease - Oxygen-induced hypercarbia from receiving too much supplemental oxygen (above 94% saturation)

There are several ways to get Hypercarbia. It can be caused by hypoventilation, where you are not getting enough air in and out of your lungs. It can also be caused by the body producing too much carbon dioxide (CO2) and not breathing out enough to compensate for it. Inhaling too much CO2 in the environment or having a lung disease can also lead to Hypercarbia.

The doctor needs to rule out the following conditions when diagnosing Hypercarbia: - Chronic and Acute obstructive pulmonary disease - Chronic and Acute restrictive lung disease - Chronic and Acute types of kidney failure - Specific medications being administered - Interstitial lung disease - Pulmonary edema - Acute respiratory distress syndrome - Sepsis - A diet that is high in carbohydrates - Injury to the central nervous system - Exposure to extra CO2 during certain surgical procedures like laparoscopy, thoracoscopy, or endoscopy - Cancer, or malignancy - Neuromuscular disorders - Obstructive or central sleep apnea - Thyrotoxicosis or myxedema coma, severe complications of thyroid diseases

To properly diagnose hypercarbia, a doctor may order the following tests: 1. Blood gas testing: This involves taking a blood sample, usually from an artery, to measure the levels of carbon dioxide (CO2) in the blood. If the CO2 level is over 45 mmHg, it suggests hypercarbia. 2. pH testing: The pH of the blood sample can be checked to determine if the hypercarbia has been present for a long time or if there is another condition affecting the body's acid-base balance. If the pH is less than 7.35, it indicates respiratory acidosis. 3. Basic metabolic panel: This blood test helps the doctor check for other health issues that may be related to hypercarbia. 4. Thyroid function testing: The function of the thyroid gland, which regulates metabolism, may need to be checked as certain thyroid diseases can contribute to hypercarbia. 5. Urine drug test: If an overdose is suspected, a urine drug test may be ordered. 6. Blood and sputum tests: If there is a possibility of infection causing fever, blood and sputum tests may be required. 7. Chest imaging: Imaging of the chest may be necessary to evaluate the lungs for any abnormalities. 8. Head imaging: In some cases, head imaging may be performed to assess the nervous system, especially if a stroke is suspected. 9. Lung function tests: Although not commonly used in emergencies, lung function tests can be helpful in diagnosing lung disease or detecting subtle changes in lung function due to nerve and muscle diseases. 10. Overnight sleep study: If a sleep disorder related to breathing, such as obesity hypoventilation syndrome, is suspected, an overnight sleep study may be ordered to monitor brain waves, blood oxygen levels, heart rate, and respiratory rate during sleep.

Hypercarbia is typically treated by helping the patient breathe better. The first option is usually non-invasive positive pressure ventilation, which delivers a steady stream of air through a full face mask. If this method doesn't work or is not appropriate, mechanical ventilation or intubation is used to support the patient's breathing. Once the patient's CO2 levels become more normal, they can gradually start to breathe independently again. In some cases, such as severe lung diseases or asthma attacks, maintaining higher CO2 levels may be necessary to prevent further complications. In severe and ineffective cases, extracorporeal carbon dioxide removal (ECCO2R) may be used. Giving the patient alkali or basic therapy to normalize pH can actually worsen the condition.

The side effects when treating Hypercarbia include: - Falling into a coma or becoming unconscious - Feeling confused, depressed, or paranoid - Experiencing panic attacks - Having irregular heart rhythm, also known as arrhythmias - Possibility of cardiovascular system failure, also referred to as cardiovascular collapse

The prognosis for hypercarbia varies depending on the underlying cause. If the cause is identified quickly and treated, the chances of recovery are good. However, in the case of patients with chronic obstructive pulmonary disease (COPD) and persistent hypercarbia, the mortality rate is higher compared to those with COPD but without persistently high levels of carbon dioxide in their blood.

You may need to see a specialist such as a neurologist, pulmonologist (lung specialist), or psychiatrist depending on the underlying cause of your hypercarbia.

Hormones and Body Chemistry Metabolic Acidosis Respiratory Failure Sepsis Thyrotoxicosis