What does a hospital use CO2 for? An overview of critical medical applications

September 28, 2025 •

4 min read

Did you know that medical-grade carbon dioxide is purified to over 99.5% to ensure patient safety? This seemingly simple gas plays multiple critical roles in modern healthcare. So, what does a hospital use CO2 for?

Quick Summary

Hospitals use purified medical-grade carbon dioxide for various critical procedures, including inflating body cavities during minimally invasive surgery (insufflation), stimulating breathing, and acting as a contrast agent for diagnostic imaging.

Key Points

Surgical Insufflation: In minimally invasive surgery, CO2 is used to inflate body cavities, creating a stable and visible workspace for surgeons.
Respiratory Stimulation: In controlled doses, a CO2 and oxygen mixture can be used to stimulate a patient's breathing post-anesthesia or during respiratory assessments.
Angiography Contrast: CO2 serves as a safe alternative contrast agent for patients with kidney problems or iodine allergies during diagnostic imaging of blood vessels.
Cryotherapy: Liquid CO2 is utilized as a cryogen to freeze and destroy abnormal or diseased tissue, such as warts and certain tumors.
Medical-Grade Purity: Medical CO2 is manufactured under strict regulations, with a purity level typically exceeding 99.5%, to ensure patient safety.
Air Quality Monitoring: Hospitals monitor ambient CO2 levels to assess and maintain proper ventilation, which is crucial for reducing the spread of airborne pathogens.

Medical Insufflation for Minimally Invasive Surgery

One of the most common and vital uses of medical-grade CO2 in a hospital setting is for insufflation during minimally invasive surgeries. This technique involves pumping gas into a body cavity to expand it, which creates a larger, more stable working space for the surgeon. Procedures such as laparoscopy, endoscopy, and arthroscopy rely on this method. Using CO2 for this purpose offers significant advantages over using regular air:

High Solubility: CO2 has a very high solubility in blood. In the rare event of a gas embolism (where gas enters the bloodstream), the body can absorb and exhale the CO2 much more rapidly than it could with nitrogen, a primary component of air. This reduces the risk of a serious, life-threatening embolism.
Non-Flammable: As a non-flammable gas, CO2 is safe to use in the presence of electrocautery and lasers, which are often used during surgical procedures.
Physiologically Compatible: The body naturally produces and processes CO2, making it a well-tolerated and safe gas to introduce into a body cavity.

The process of insufflation gives surgeons a clear, magnified view of internal organs via a camera, allowing for better precision and less trauma compared to open surgery. This leads to reduced recovery times and less postoperative pain for the patient.

Respiratory Stimulation and Critical Care

While we typically exhale carbon dioxide, controlled doses can be used therapeutically in respiratory medicine. A mixture of CO2 and oxygen, known as Carbogen, is sometimes administered to stimulate a patient's breathing. This can be beneficial in several scenarios:

Arousing from Anesthesia: Post-anesthesia, a patient's breathing may be suppressed. A controlled CO2 mixture can help stimulate the respiratory drive and encourage normal breathing.
Respiratory Assessments: In some cases, doctors use CO2 to assess the body's respiratory response, particularly in patients with chronic respiratory diseases.
Cardiovascular Procedures: The use of CO2 in conjunction with other gases is crucial in certain cardiovascular procedures, where a controlled physiological response is needed.

Monitoring Air Quality in Critical Areas

Beyond direct patient treatment, hospitals also monitor CO2 levels to ensure optimal ventilation and air quality, especially in operating rooms, patient wards, and waiting areas. Elevated CO2 levels can indicate poor airflow, which is a concern for airborne disease transmission and can impact patient and staff well-being. Using continuous CO2 monitoring helps facilities maintain compliance with safety standards and manage energy consumption efficiently.

CO2 as a Contrast Agent for Imaging

For some diagnostic procedures, CO2 can be used as a contrast agent to visualize blood vessels. This is an invaluable alternative for patients who have:

Kidney dysfunction: Iodinated contrast agents, which are commonly used, can be toxic to the kidneys. CO2 offers a safe, nephrotoxic-free option.
Iodine allergy: Patients with an allergic reaction to iodine can safely undergo angiography using CO2.

In this application, CO2 acts as a negative contrast agent, appearing black on an angiogram. It displaces blood in the vessel, creating a clear image of the vessel walls and surrounding structures. Because CO2 is highly soluble, it is quickly absorbed and exhaled, minimizing any risk of complications.

Cryosurgery and Other Therapeutic Uses

Liquid CO2 serves as a cryogen, a substance that produces extremely low temperatures, for use in cryosurgery. This procedure involves freezing and destroying abnormal tissue. It is often used to treat conditions such as:

Warts and skin lesions
Certain tumors
Precancerous cells

The precise and controlled freezing action of liquid CO2 minimizes damage to surrounding healthy tissue, making it a targeted and effective therapeutic tool. The properties of CO2 make it a safe and controllable medium for this delicate procedure.

Medical-Grade vs. Industrial CO2: A Critical Distinction

Understanding the difference between medical-grade and industrial-grade CO2 is paramount in healthcare. The distinction is critical for patient safety and regulatory compliance.


Characteristic	Medical-Grade CO2	Industrial-Grade CO2
Purity	≥99.5% purity, with strict controls for impurities.	Varies widely, may contain contaminants unsuitable for medical use.
Regulation	Regulated as a medical gas under strict government standards (e.g., FDA).	Subject to industrial safety standards, not for patient use.
Sourcing	Sourced from certified suppliers and undergoes rigorous testing.	Sourced for various industrial applications like food processing or welding.
Handling	Handled with specific equipment and protocols for controlled, sterile delivery.	Handling procedures differ and are not suitable for clinical use.
Uses	Insufflation, respiratory stimulation, cryosurgery, angiography.	Enhanced oil recovery, food and beverage carbonation, welding.

The strict manufacturing and quality control standards for medical-grade CO2 ensure it is sterile, pure, and safe for direct application in and on the human body. This process is documented and traceable to maintain high standards of care.

The Role of CO2 in Future Healthcare

The use of CO2 in hospitals is an evolving field, with ongoing research exploring new applications and optimizing existing procedures. Innovations in insufflation technology, advanced angiography techniques, and enhanced monitoring systems all contribute to safer and more effective patient care. Its versatility and physiological compatibility mean it will continue to be a cornerstone of modern medicine.

For more in-depth information on the various medical applications of gases and regulations surrounding their use, you can explore resources from the National Institutes of Health.

Conclusion: A Versatile Gas at the Heart of Modern Medicine

From the operating room to the respiratory ward, carbon dioxide is a surprisingly versatile and essential medical gas. Its applications in minimally invasive surgery, respiratory therapy, and diagnostic imaging highlight its importance in providing safe and effective healthcare. The rigorous standards governing its production and use underscore the medical community's commitment to patient safety. The next time you consider the many tools at a hospital's disposal, remember that this simple gas plays a critical role in some of the most advanced medical procedures available today.

Frequently Asked Questions

CO2 is highly soluble in blood, so any gas that enters the bloodstream is quickly absorbed and exhaled by the body, minimizing the risk of a dangerous gas embolism. It is also non-flammable, making it safer to use with surgical tools like lasers.

No. While chemically identical, medical-grade CO2 is manufactured under strict regulations and is purified to a much higher standard (typically >99.5%) to ensure it is free of contaminants that could be harmful to patients. Industrial CO2 does not meet these medical purity requirements.

In specific therapeutic contexts, a medical gas mixture that includes a controlled amount of CO2 (Carbogen) can be administered to a patient. This slightly increases the CO2 concentration in the blood, which triggers the brain's respiratory center to increase the rate and depth of breathing.

As with any medical gas, there are risks, but they are mitigated through careful monitoring and protocols. For example, during insufflation, there is a small risk of a CO2 embolism, but its high solubility makes it less dangerous than an air embolism. Trained medical professionals manage the delivery to ensure patient safety.

CO2 is a 'negative' contrast agent, meaning it appears as a void (dark area) on X-ray imaging. This contrasts with traditional 'positive' contrast agents like iodine, which appear bright white. Its use is particularly valuable for patients who cannot receive iodine-based agents.

Monitoring CO2 levels in the air helps assess ventilation efficiency. High CO2 levels can indicate poor air circulation, which is a risk factor for the buildup of airborne pathogens. This monitoring helps staff identify and address ventilation issues to protect patients and staff.

In cryosurgery, a stream of liquid CO2 is applied to targeted tissue. The rapid expansion of the liquid into gas causes a rapid drop in temperature, freezing and destroying the targeted abnormal cells or tissue while minimizing damage to the surrounding healthy areas.