Penn Veterinary Supply, Inc. - Since 1981

“If you have a gas analyzer for inhalants, you have a good idea of how much of the inhalant is in the animal's body every time it exhales,” - Mike Barletta, DVM, MS, PhD, DACVAA, DVM360 Magazine, November 16, 2019”

Multi-parameter monitoring within Veterinary medicine has made several leaps and bounds throughout the past 20 years. Arguably the most significant achievements in surgical monitoring have been within the scope of measuring clinically significant gas exchange, specifically Pulse Oximetry and Capnography.

Capnography measures carbon dioxide in a patient’s breath over time. Most Veterinarians and Techs know Capnography as ETCO₂, or end-tidal CO₂. End-tidal CO₂ (ETCO₂) values normally range from 35 to 45 mm Hg in dogs and 28 to 32 mm Hg in cats.

Measuring end-tidal CO₂ during surgery can provide significant clinical information and insights during Veterinary Surgery. ETCO₂ values are often the first and earliest indicator of some sort of metabolic distress that the pet might be experiencing.

Monitoring ETCO₂ Values can help determine:

• Levels of metabolic stress and disturbances.

• Problems or leakage in an endotracheal tube.

• Misplacement of the endotracheal tube in the esophagus.

Perhaps the most clinically significant achievements in gas monitoring have been made through technological advances involve the simultaneous measurement and monitoring of end-tidal Carbon Dioxide(ETCO₂) and Anesthetic Inhalants such as Isoflurane and Sevoflurane. While once cost prohibitive for the majority of companion animal clinics, Veterinarians can now affordably measure, analyze, and monitor both ETCO₂ and Anesthetic Agents.

It is important to measure and monitor the inhalation and exhalation volume of Anesthetic Inhalants to help ensure proper calibration and functioning of a Vaporizer. With a properly functioning Vaporizer, the dial setting number will correspond to a certain amount of gas output, usually Isoflurane or Sevoflurane. However, Vaporizers are also known for being affected and influenced by temperature and time. Colder temperatures of the liquid anesthetic agent can lead to lower vaporizer output. Depending on how frequently the vaporizer is calibrated, the risk of the vaporizer losing calibration increases with time. One important component of the Vaporizer is the thermostat. Thermostat Calibration cannot be performed on-site in almost all cases because it has to be done in a temperature controlled environment. Calibrating a vaporizer thermostat can take up to 5 days.

Technology, like the Dual Gas Module from Bionet America, helps Veterinary clinics affordably measure both end-tidal CO₂ and Anesthetic Inhalants. While standalone CO2 sensors often only provide parameters such as ETCO₂, FiCO₂, and Respiration Rate, products like the Dual Gas Module measure:

• EtCO₂

• FiCO

• Respiration Rate

• Apnea Detection Time

• Anesthetic Agent Concentration

• MAC (Minimum Alveolar Concentration)

• Iso % Volume

• Sevo % Volume

• Halothane % Volume

• Enflurane % Volume

• Desflurane % Volume

Along with helping to ensure proper Vaporizer function, a gas analyzer like the Dual Gas Module can also help to prevent both underdosing and overdosing of the inhalant. A thorough understanding and awareness of anesthetic gas levels can help guide clinical decision making. As part of your overall multiparameter monitoring needs, consider using an analyzer that measures both ETCO₂ and Anesthetic agents, especially during those more complex surgeries that require a higher level of monitoring.