Anesthesia monitoring and vital parameters
Patient watch from induction to awakening
Anesthesia is never routine, no matter how often it is performed. Anesthesia affects breathing, circulation and temperature regulation all at once, and changes can occur rapidly. Your task is to keep the patient under constant observation and detect deviations before they become critical.
§Preoperative risk assessment
Before anaesthesia, the patient's physical condition is assessed so the anaesthetic can be tailored. An internationally used tool is the ASA classification (American Society of Anesthesiologists), which classifies the patient according to physical status — from a healthy patient to a critically ill. The higher the class, the greater the risk and the greater the demands on monitoring and preparation. The classification is done by the veterinarian, but you must understand what it means for your work.
§The vital parameters
Monitoring is based on following a number of parameters over time and reacting to changes. Combine the equipment with your own observations — equipment can fail, but a comprehensive clinical assessment rarely fails.
| Parameters recorded at fixed intervals | What it tells you | How it is followed |
|---|---|---|
| Breathing | Oxygenation and ventilation | Frequency, depth, chest movements, capnography |
| Circuit | Heart rate and blood supply | Pulse, heart rate, ECG, blood pressure |
| Oxygenation | Oxygen in the blood | Pulse oximetry (SpO2), mucous membrane color |
| Temperature | Risk of hypothermia | Thermometer/probe, repeated measurements |
| Anesthesia depth | Whether the animal is appropriately stunned | Reflexes, eye position, muscle tone, response |
§Anesthesia depth
For shallow anaesthesia gives pain and movement; for deep anaesthesia suppresses breathing and circulation. Assessing depth from reflexes eye position jaw tension and response — and reporting changes to the vet — is a central nursing task throughout the procedure.
§Hypothermia — a known pitfall
Anaesthesia inhibits the body's temperature regulation, and the patient easily loses heat — especially small animals with large surface in relation to body mass. Hypothermia prolongs awakening, affects heart rhythm and changes how drugs are metabolized. Therefore, temperature is monitored continuously, and the animal is kept warm with suitable aids during and after the procedure.
§Documentation under anaesthesia
Parameters and preparation
“Monitoring is not about reading numbers, but about spotting a trend in time. The person who spots the change early saves the patient.”