Vet Tech PRN

This why capnography is a must-have piece of equipment.

Tech Tip Tuesday: Capnography Case Scenario

You’re monitoring a dog under anesthesia for a routine spay.

Everything has been stable until you notice this:

• ETCO₂ was 38 mmHg… now trending down to 25 mmHg
• The waveform is getting smaller
• Your patient’s SpO₂ still reads normal

ETCO2=35−45 mmHg

What’s your next move?

Before you assume hyperventilation...pause.

Low ETCO₂ doesn’t always mean the patient is “breathing too well.”

Think through your differentials:

Could this be:
• A disconnect in the circuit?
• A leak in your ET tube cuff?
• Decreased cardiac output?
• Early sign of impending arrest?

Now check your patient:
You quickly assess:

Chest movement → present
Reservoir bag → feels normal
Pulse quality → weak

Now your concern shifts.

ETCO2 not only measures ventilation issues, this could be circulatory compromise.

Why this matters:
Capnography often changes before anything else. A dropping ETCO₂ with a weakening pulse should immediately make you think about perfusion, not just breathing.

Technician Insight:
Capnography is one of the earliest indicators of decreased cardiac output.

If you only look at the number, you’ll miss it.
If you interpret the trend with your physical assessment of the patient, you’ll catch it early.

Targeted evidence-based and actionable educational resources can increase veterinarians’ intentions to follow antibiotic stewardship guidelines. 💊

Open access article: jav.ma/antimicrobial5