When your cat undergoes anaesthesia, ensuring their safety is a top priority for us. One of the most important tools used during anaesthesia is capnography, a method that measures the amount of carbon dioxide (CO2) in your cat’s exhaled breath. This measurement is crucial because it provides real-time information about your cat’s breathing and overall cardiovascular status while under anaesthesia.
What is Capnography?
Capnography involves the continuous monitoring of CO2 levels in the air that your cat exhales. CO2 is a waste product of metabolism, transported via the blood to the lungs for exhalation. Monitoring CO2 helps us assess how well your cat is ventilating, ensuring that their lungs are effectively removing CO2 from the body. This is especially important during anaesthesia because many anaesthetic agents can depress the respiratory system, leading to shallow or irregular breathing.
Why is Capnography Important During Anaesthesia?
During anaesthesia, the natural reflexes that help regulate breathing are often suppressed, which can lead to inadequate ventilation. Without proper ventilation, CO2 can build up in the blood, leading to a condition called hypercapnia. This can cause complications such as increased heart rate, high blood pressure, and, in severe cases, can depress the central nervous system, making it critical to monitor and adjust ventilation as needed.
Capnography provides the veterinariary team with a clear picture of your cat’s respiratory status, allowing for the early detection of potential issues like:
Hypoventilation: When your cat is not breathing deeply or frequently enough, leading to a buildup of CO2.
Apnea: A complete pause in breathing, which can be life-threatening if not addressed immediately.
Airway Obstruction: If something is blocking your cat’s airway, the capnography waveforms will change, alerting us to the problem.
How Capnography Works
The capnography machine measures CO2 in two main ways: mainstream and sidestream. Mainstream capnography measures CO2 directly from the air your cat breathes out through a sensor attached to the end of the breathing tube. This method gives an almost instant reading but can be a bit bulky. Sidestream capnography, on the other hand, draws a small sample of air from the breathing tube and analyses it. While there’s a slight delay in the readings, this method is less cumbersome and easier to use with small animals like cats.
The machine itself passes a beam of infra-red light through the sampled gas. The CO2 absorbs this light and the resultant residual light is measured by a sensor, giving an inverse indication of the CO2 levels in the sample.
Detecting and Preventing Complications
Capnography is more than just a monitoring tool; it’s a lifesaver. It helps us detect issues before they become serious. For example, a sudden drop in CO2 levels might indicate a problem with the heart or a major airway obstruction, prompting immediate action.
In cases where your cat’s CO2 levels are too high or too low, our team can make quick adjustments, such as altering the depth of anaesthesia, providing additional supplemental oxygen, or even initiating manual ventilation to help your cat breathe better.
Key Points
Capnography is an essential part of modern veterinary anaesthesia, ensuring that your cat remains safe and stable throughout the procedure. It allows for real-time monitoring and quick intervention, reducing the risk of complications and helping to ensure that your cat wakes up happy and healthy after their surgery. Next time your cat requires anaesthesia, you can rest a little easier knowing that advanced tools like capnography are keeping them safe.
Check out our other blog posts about anaesthesia monitoring to learn more about how we strive to keep your cat safe -