Why is carbon dioxide used in surgical procedures

Carbon Dioxide in Surgery

Facts and Figures

Current atmospheric CO2 levels are 0.04%. CO2 levels of 0.12% are considered to affect brain metabolism and neural activity. The density of CO2 is 1.5 times that of air, and it is 25 times more soluble in blood and tissue than air at 37 – 38 °C (Ng and Rosen., 1968).

Why Use CO2 During Surgery?

There are three known benefits to using CO2 during surgical procedures:

1. EMBOLI – CO2 insufflation over a surgical wound displaces the available air. Since CO2 is 25 times more soluble in blood and tissue than air is at 37°C, arterial CO2 emboli are much better tolerated than air emboli. Additionally, using the TEMED Gas Diffuser can enhance the deairing of the chest cavity, further minimizing this risk.

2. INFECTION - CO2 has antimicrobial properties, reducing the incidence rate of surgical site infections. Carbon dioxide has been utilized since the 1930s to inhibit microbial growth (Dixon and Kell., 1989), and its effectiveness is evident in laparoscopic procedures, which show a 40% reduction in surgical site infections compared to open colorectal surgery (Aimag et al., 2011).

3. HEALING – CO2 enhances wound healing by promoting the Bohr Effect, which results in a higher off-loading of oxygen from hemoglobin to surrounding blood and tissues. The administration of CO2 helps improve microcirculation and local oxygen supply, crucial for effective healing.

EMBOLI: Preventing Air Embolism by Displacing the Available Air with Carbon Dioxide.

This process was first reported as a means of preventing cerebral or myocardial damage during open heart surgery procedures in 1967 (Selman et al., 1967). When carbon dioxide is insufflated into the thoracic cavity, it fills the cavity by gravity, effectively replacing the air. Transoesophageal echocardiography has shown a reduction in the number of intracardiac emboli during procedures where CO2 has been used.

A study in 1968 found that 0.5 ml/kg of air placed into a carotid artery of dogs always leads to severe neurological damage, whereas 4 to 8 ml/kg of CO2 produced transient signs in only 33% of dogs, with all cases resulting in full recovery (Ng and Rosen., 1968). Other studies have confirmed that CO2 arterial emboli are much better tolerated than air emboli (More and Braselton., 1940; Eguchi and Bosher., 1962).

Several studies conducted a decade ago found that using an open-ended piece of tubing to insufflate CO2 caused a high-velocity jet into the open surgical wound, creating turbulence and poor deairing efficiency (Persson et al., 2004). It is more beneficial to use a device like the Medtronic TEMED Gas Diffuser that has a diffusing tip, allowing for low-velocity CO2 delivery and efficient deairing of the thoracic cavity.

INFECTION: CO2 has antimicrobial properties, reducing the rate of surgical site infections.

Carbon dioxide can stimulate or inhibit cell development in microorganisms (Debs-Louka et al., 1999). Its use in laparoscopic techniques has significantly reduced surgical site infection rates compared to open procedures (Howard et al., 2010). A study showed that patients undergoing laparoscopic cholecystectomy had significantly lower infection rates than those undergoing open procedures, further indicating the benefits of CO2 in surgery.

HEALING: CO2 improves microcirculation and wound healing.

Wound healing benefits from improved microcirculation and local oxygen supply. The administration of subcutaneous carbon dioxide has shown to promote neoangiogenesis and increase tissue oxygenation values, leading to better healing outcomes (Brandi et al., 2010). The Bohr Effect enhances oxygen delivery to tissues, further accelerating recovery at the surgical site.

References include a variety of studies that support the effectiveness of CO2 in surgical procedures, particularly regarding emboli prevention, infection reduction, and healing enhancement.