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11 Fall/Winter 2021 | Equine Solutions Capnography is the measurement of carbon dioxide in the patient's breath and is an essential tool in providing vital information on ventilation, tissue perfusion, cellular metabolism, and anesthetic response. Importantly, it also confirms correct placement of the endotracheal tube and helps to allow the veterinarian to maintain normocapnia for safe and adequate anesthetic depth. Horses are susceptible to hypercapnia during anesthesia due to ventilation/perfusion (V/Q)-mismatch, which the capnograph in correlation with arterial blood gas monitoring can easily and quickly identify. This continual evaluation of CO 2 levels can alert you to any concerns, allowing for rapid response time - an essential factor ensuring the balance between safe, but effective, anesthetic depth. With horses, we often take an arterial blood sample to check the values and adapt ventilation throughout surgery. Because of the V/Q (ventilation- perfusion) mismatch in horses due to their size, weight, position and pressure on the diaphragm during surgery, in combination with horses often being hypotensive during anesthesia (due to their position causing pressure to be applied to the blood vessels, and the effect of anesthetic drugs), this often results in significant problems during anesthesia and, more importantly, during the recovery and post-operative period. We feel that normocapnia is maintained between 35 and 45mmHg. If your CO 2 reading rises higher than 45mmHg, choose to mechanically ventilate or adopt adaptation ventilation until normocapnia occurs. Evaluation of the capnogram also allows you to check that there are no leaks present in the system, and that there is no breathing against the respirator. Sidestream capnography is used at Clinique Equine Acy- Romance because it is found to provide the most reliable readings and is easy to use. TIP When placing the sidestream capnograph line next to the endotracheal tube, ensure it is facing upward to prevent condensate going into the line and obstructing it. Anesthesia monitoring equipment – Order of set-up Capnography CO 2 Capnography is the measurement of carbon dioxide in the patient's and is an essential tool in providing vital information on ventilation, perfusion, cellular metabolism, and anaesthetic response. Importantly, also confirms correct placement of the endotracheal tube and helps the veterinarian to maintain normocapnia for safe and adequate anaesthetic depth. Horses are susceptible to hypercapnia during anaesthesia due ventilation/perfusion (V/Q)-mismatch, which the capnograph in correlation with arterial blood gas monitoring can easily and quickly identify. This continual evaluation of CO 2 levels can alert you to any concerns, allowing rapid response time - an essential factor ensuring the balance between but effective, anaesthetic depth. Pulse Oximetry – SpO 2 Horses are known to be highly susceptible to hypoxemia, especially a recumbent horse is placed in the dorsal position for surgery. Anaesthetic drugs can induce hypoventilation or apnea, which will lead to ventilation- perfusion mismatch (V/Q defects) in the lungs. The gold standard for measuring PaO 2 is through an analysation of sample, by checking for oxygen in the arterial blood. However, another We feel 45mmHg. choose ventilation capnogram leaks against Sidestream Romance readings TIP: next upward obstructing Sidestream capnograph line facing upward With horses, we often take an arterial blood sample to check the values Because of the V/Q (ventilation- perfusion) mismatch in horses due diaphragm during surgery, in combination with horses often being hypotensive causing pressure to be applied to the blood vessels, and the effect of problems during anaesthesia and, more importantly, during the recovery Multiparameter monitor used at Clinique Equine Acy-Romance Sidestream capnograph line facing upward Vascular access Place E.T Tube Connect to anesthesia machine Turn on ventilator Place infusion line Place capnograph line Place pulse oximeter clip Place ECG sensors Place IBP line Place Temp probe Monitored on a multiparameter monitor Capnography CO 2