What is the tachycardia threshold for a cat during stage III anesthesia?

What is the tachycardia threshold for a cat during stage III anesthesia?

• A. >180 bpm
• B. >200 bpm
• C. >160 bpm
• D. >220 bpm

Answer: (B)

During stage III anesthesia in a cat, a heart rate that climbs above about 200 beats per minute signals a sympathetic response from either inadequate depth of anesthesia or pain, rather than a normal variation. Cats typically maintain a relatively high HR under anesthesia, but exceeding 200 bpm suggests the plane of anesthesia may be too light or there’s an active stimulus needing analgesia. This threshold guides you to reassess and adjust the anesthesia: increase depth modestly, ensure adequate analgesia, and check respiratory status (oxygenation and ventilation) and circulation (blood pressure, perfusion). If the HR is not responsive to depth and analgesia adjustments, investigate other factors such as hypoxemia, hypercapnia, hypovolemia, or an underlying arrhythmia. Among the options, a value over 200 bpm is the most appropriate cue to intervene, whereas lower thresholds would more likely reflect normal variation or less concerning conditions.

During stage III anesthesia in a cat, a heart rate that climbs above about 200 beats per minute signals a sympathetic response from either inadequate depth of anesthesia or pain, rather than a normal variation. Cats typically maintain a relatively high HR under anesthesia, but exceeding 200 bpm suggests the plane of anesthesia may be too light or there’s an active stimulus needing analgesia. This threshold guides you to reassess and adjust the anesthesia: increase depth modestly, ensure adequate analgesia, and check respiratory status (oxygenation and ventilation) and circulation (blood pressure, perfusion). If the HR is not responsive to depth and analgesia adjustments, investigate other factors such as hypoxemia, hypercapnia, hypovolemia, or an underlying arrhythmia. Among the options, a value over 200 bpm is the most appropriate cue to intervene, whereas lower thresholds would more likely reflect normal variation or less concerning conditions.