Equipment Troubleshooting

Anesthesia Machine - Machine Moods Quick Fixes

• Leaks:
  • High-Pressure (cylinder to flowmeters): Check yokes, O2 flush.
  • Low-Pressure (flowmeters to CGO): Check vaporizers, hoses.
    • Circle System: Positive pressure leak test (<30 cm H2O loss/min at 30 cm H2O).
    • Bain Circuit: Pethick test (inner tube leak → Venturi effect).
• Oxygen Supply Failure:
  • Pipeline Failure: Open backup O2 cylinder; disconnect wall.
  • O2 Analyzer Alarm: Calibrate; if fails, replace.
• Ventilator Issues:
  • Failure to cycle / Bellows issues: Check drive gas, power, circuit, APL valve.
• Vaporizer Problems:
  • Tipped: Purge high O2 flow (5-10 L/min) for 20-30 min.
  • Wrong agent / Empty: Drain/flush / Refill.

⭐ Tipped vaporizer: Purge with high O2 flow (5-10 L/min) for 20-30 min to prevent overdose. Critical step!

Breathing System - Circuit Chaos Vent Zen

• Systematic check: Patient → Circuit → Machine. 📌 DOPE (Displacement, Obstruction, Pneumothorax, Equipment) for rapid troubleshooting.
• Common Circuit Faults & Signs:
  • Leaks: ↓$V_T$, ↓PIP, hiss. Check connections, ETT cuff, APL.
  • Obstruction: ↑PIP, ↓$V_T$, wheeze. Check ETT (kink, plug), HME, tubing.
  • Disconnection: Critical! ↓PIP, ↓$V_T$, sudden ↓/absent ETCO₂. Verify immediately.
  • Valve Malfunctions: Sticking valves → rebreathing, ↑ETCO₂.

⭐ Sudden ETCO₂ drop to zero + low pressure alarm = Circuit Disconnection. (Critical sign!)

• Key Ventilator Alarms:
  • High Pressure: Set 10-15 cm H₂O > PIP. Indicates obstruction, patient resistance, or ↓compliance.
  • Low Pressure/Volume: Signals leak or circuit disconnection.

Airway & Monitoring - Airway Alerts Monitor Master

• ETT Issues: 📌 DOPE Mnemonic:
  • Displacement (esophageal, endobronchial)
  • Obstruction (kink, secretions, cuff)
  • Pneumothorax
  • Equipment failure (ventilator, circuit)
• Ventilator Alarms:
  • High Pressure: Kink, obstruction, bronchospasm, ↓compliance.
  • Low Pressure: Leak, disconnect, cuff leak, extubation.
• Capnography (EtCO2):
  • Sudden ↓: Disconnect, esophageal intubation, cardiac arrest, PE.
  • Sudden ↑: Hypoventilation, rebreathing (e.g., exhausted soda lime).

  ⭐ Sudden loss of EtCO2 waveform (near zero) with heart sounds often indicates esophageal intubation or circuit disconnection.

• Pulse Oximetry (SpO2):
  • Low SpO2: Hypoxia, probe issue, poor perfusion, motion, dyshemoglobinemia. Verify patient, connections, probe.

Vaporizers & Gas Supply - Vapor Vibes Gas Guides

• Vaporizers: Convert liquid to vapor; add to Fresh Gas Flow (FGF).
  • Types: Variable bypass (Tec), Measured flow (DIVA).
  • Safety: Keyed fillers, interlock system.
  • Hazards: Tipping (overdose risk), wrong agent. Check fill, agent, leaks.
• Gas Supply: Cylinders & Pipeline.
  • Pipeline: O₂, N₂O, Air at 50-55 psig. DISS protected.
  • Cylinders: PISS protected. Regulators ↓ pressure to 45-50 psig.
    • O₂ (White): 2200 psig, 660L (E-cyl).
    • N₂O (Blue): 745 psig (liquid present), 1590L (E-cyl).
    • Air (Black/White): 1800 psig, 625L (E-cyl).
  • O₂ Fail-safe: ↓ O₂ pressure → ↓ N₂O.
  • O₂ Flush: 35-75 L/min. ⚠️ Barotrauma.

⭐ Pin Index Safety System (PISS) prevents incorrect cylinder attachment. O₂ pins: 2-5; N₂O: 3-5; Air: 1-5.

High‑Yield Points - ⚡ Biggest Takeaways

• Human error is the leading cause of anesthesia critical incidents, often equipment misuse.
• Oxygen supply failure: Check pipeline, then cylinder; use Ambu bag if unresolved.
• Zero CO2 on capnograph: Suspect esophageal intubation, disconnection, or cardiac arrest.
• High airway pressure alarm: Check for kinked ETT, bronchospasm, secretions, or pneumothorax.
• Low airway pressure alarm: Indicates circuit disconnection, cuff leak, or other system leaks.
• Pulse oximeter errors: Caused by poor perfusion, nail polish, ambient light, dyshemoglobins.
• Pre-use machine checkout is vital to prevent most equipment failures.