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ETCO2 Rise Laparoscopy Ventilation — FRCA Final MCQ

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EasyGeneral AnaesthesiaETCO2 Rise Laparoscopy VentilationFRCA Final

A 45-year-old woman (ASA II) is having laparoscopic cholecystectomy. An LMA is in situ. The surgeon insufflates CO2 to 15 mmHg. ETCO2 gradually rises from 4.5 to 6.8 kPa over 30 minutes. What is the most appropriate ventilatory adjustment?

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Correct answer: B — Either increase RR or VT to increase minute ventilation

During laparoscopic surgery, CO2 is absorbed from the peritoneal cavity into the systemic circulation, increasing PaCO2 and ETCO2. This is exacerbated by Trendelenburg position (reduced FRC, increased dead space). The appropriate response is to increase minute ventilation by increasing either respiratory rate or tidal volume (or both) to maintain ETCO2 at 4.5-5.5 kPa. Typically a 15-25% increase in MV is required. If ETCO2 continues to rise despite increased MV, consider: subcutaneous emphysema, capnothorax, or CO2 embolism.

Reference: RCOA – 2023 – Laparoscopic surgery physiology; AAGBI – 2020 – Laparoscopic safety