On Your Own — Troubleshooting

At some point you'll be alone in the room. When you have to react, stay calm and make your movements count — an organized mind and an organized cart are half the battle. Call your attending early; they expect the call and would rather fix something small than something big.

Have ready, every case: your attending's number, how to reach the anesthesia tech, and the circulator's name. The hemodynamic goal is HR/BP within ~20% of baseline (~10% for the critically ill).

Don't fixate on one number. Treat the whole system. Remember BP = CO × SVR = (HR × SV) × SVR — ask "how are the HR and BP related?" before you treat.

A downtrending SpO₂ is a problem — act as it nears 92% (there's a ~20–30 s lag between the lungs and the finger probe). Work the checklist:

1. Call your attending.
2. Check the EtCO₂ — waveform changed or gone? Did the patient stop breathing? Is the circuit disconnected? (Eyeball the whole circuit — the most common disconnect is at the Y-adapter / ETT.)
3. Is the pulse-ox probe still on the patient?
4. 100% O₂.
5. Switch to hand-ventilation and feel the compliance — bronchospasm?
6. Breath sounds — equal? If one-sided: right mainstem (pull the ETT back until bilateral) or pneumothorax (needs a chest tube).
7. Consider larger recruiting breaths, and suction the ETT if peak pressure is high.
8. Still stuck? Get your attending in the room.

EtCO₂ is, with HR, your most responsive monitor.

Falling / absent EtCO₂ — a disconnect until proven otherwise, but could be a big problem: - Make sure the monitor isn't auto-zeroing; look for bag/bellows movement; confirm the patient is connected. - CO₂ detector issues: kinked/disconnected sample line, full water trap. - Hand-ventilate; check breath sounds (good tidal volume? equal? one-sided → mainstem/pneumothorax); compliance (bronchospasm?). - Leak? — ruptured/under-inflated ETT cuff, or a machine leak (call the tech). - Over-ventilating? Check TV/RR. And check vitals — a low cardiac output or PE drops EtCO₂.

Rising EtCO₂ — most commonly under-ventilation; the most dangerous cause is malignant hyperthermia. - Under-ventilated? Check TV/RR and PIP; if breathing spontaneously, assist. - MH? Look for the company it keeps — tachycardia, hypertension, masseter spasm, rising temperature — and get an ABG. (See the [Emergency Manual](/emergency) for the full MH drill: stop triggers, dantrolene, cool, call MHAUS.)

The "high PIP" alarm on the ventilator — work through it:

1. Call your attending.
2. Is the patient light / "fighting" the vent? Deepen — opioid or propofol bolus, dial up the gas. (Does it also need more relaxant? Deepen the anesthetic first, then check twitches and give relaxant.)
3. Hand-ventilate and check breath sounds — equal, or right-sided (mainstem)? More distant on one side (pneumothorax)? Stiff (bronchospasm)?
4. Kinked or obstructed ETT/circuit? Suction the ETT.
5. In laparoscopic cases — is the abdominal insufflation pressure too high?

First, sanity-check the measurement (cuff size; if using an A-line, re-cycle the NIBP and check the transducer is leveled at the heart). If the cuff won't read at all, feel a pulse — most often it's a very low BP, so treat it. Then use the grid:

Causes of ↑HR/↑BP that don't respond to deepening: ETT on the carina, tourniquet pain, and MH.

Movement usually means not enough anesthetic (sometimes it's just the BP cuff cycling and the surgeon feeling it). You'll often see HR/BP climb before the patient moves. Movement under anesthesia doesn't necessarily mean recall — but act quickly:

1. Check vitals — stable?
2. Make sure the patient isn't sliding off the table.
3. Deepen — opioid bolus / dial up vapor; if hemodynamically stable, propofol 0.5–1 mg/kg.
4. Need more relaxant? Deepen first, then check twitches and paralyze — giving relaxant alone to stop movement risks awareness. If HR/BP won't tolerate more anesthetic, use pressors so you can deepen.