- Design
- Prospective randomised controlled trial, single centre
- Population
- 36 ASA I–II adults having elective endolaryngeal surgery
- Primary outcome
- PaCO2 over time during surgery
- Effect
- End-of-surgery PaCO2 66.5 vs 44.5 mmHg (high-flow vs jet; P<0.001); pH 7.21 vs 7.31
A Turkish trial randomised 36 ASA I–II adults having elective endolaryngeal surgery under total intravenous anaesthesia and paralysis to high-frequency jet ventilation or apnoeic high-flow nasal oxygen (THRIVE).
CO2 was similar at 10 minutes. By 20 minutes PaCO2 was higher with high-flow oxygen (median 55.5 vs 44.5 mmHg), and by the end of surgery it reached 66.5 mmHg against 44.5 mmHg, with pH 7.21 against 7.31 and lactate 3.4 against 2.5 mmol/L. Oxygenation was also better with jet ventilation later in the case.
High-flow oxygen gives an unobstructed tubeless field, which surgeons value. This small trial suggests it suits short procedures, and that longer cases need a plan for CO2 clearance — jet ventilation, intermittent intubation or a planned stop point agreed with the anaesthetist.
- Agree an expected duration with the anaesthetist before choosing apnoeic high-flow oxygen.
- Consider jet ventilation or a tube for laryngeal procedures likely to exceed about 20 minutes.
- Expect progressive hypercapnia during apnoeic high-flow technique even with good oxygen saturation.
- Check arterial or transcutaneous CO2 in longer tubeless cases where available.
Why it matters
Normal oxygen saturation during tubeless surgery can hide a steadily rising CO2.
Don't overread it
With 36 fit adults, this cannot set a safe limit for sicker patients.
The statistics, in plain English
Median values from 18 patients per group are imprecise, but a 22 mmHg CO2 difference by the end of surgery is large and clinically meaningful.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for ent & head and neck surgery, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free