High-Flow Nasal Oxygen During Vitrectomy Sedation
Eye surgery under regional block plus moderate sedation leaves little room for airway fuss. A randomized trial published October 14, 2026 in the Journal of Clinical Medicine compared high-flow nasal oxygenation (HFNO) with low-flow nasal oxygenation during moderate multimodal analgosedation for elective pars plana vitrectomy.
The study
One hundred sixty-four adults with ASA physical status I to III were randomized to HFNO at 40 L/min with set FiO2 0.40, or low-flow nasal oxygen at 5 L/min meant to approximate a similar nominal FiO2. Sedation used remifentanil with a Patient State Index target around 80 to 85, plus a retrobulbar or sub-Tenon block. The primary outcome was staying in a target SpO2 band of 94 to 98% without hypoxemia (SpO2 below 90%) at three preset time points.
No patient in either group had SpO2 below 90%, so the primary outcome did not differ. Below-target oxygenation (SpO2 90 to 93%) was less common with HFNO during and after the procedure. Treatment effects on breathing frequency and measured end-tidal CO2 varied by ASA class. In exploratory ASA III analyses, HFNO was linked to higher breathing frequency, fewer clinically significant bradypnea episodes, and lower measured EtCO2 than low-flow oxygen.
Why it matters
This is a useful reminder that a quiet SpO2 number under supplemental oxygen is not the whole respiratory story. When FiO2 is roughly matched, both strategies avoided frank hypoxemia. The signal for HFNO showed up more in intermediate desaturation and in respiratory pattern, especially in higher ASA patients. That matches the worry many of us have already: oxygen can mask hypoventilation if we only watch the pulse oximeter.
What it means for practice here
For healthier ASA I and II vitrectomy patients, low-flow oxygen often looks adequate under a careful sedation plan. For ASA III patients, I am more willing to reach for HFNO when the setup allows it, while still watching breathing rate, EtCO2 when I can get a usable sample, and depth of sedation. I also keep Horiuchi's caution in mind: high inspired oxygen can make SpO2 look fine while ventilation drifts.
Single-center data, unblinded event capture, and EtCO2 measurement under high nasal flow all limit how hard I lean on the numbers. Still, the practical takeaway is simple. Match the oxygen strategy to the patient's risk, and do not let a pretty saturation replace actual respiratory monitoring.
Source
- Vuković A, Jukić T, Štanfel M, Mandić K, Mihaljević S, Bartolek-Hamp D. High-flow nasal oxygenation is associated with improved respiratory stability during moderate multimodal analgosedation for pars plana vitrectomy: a randomized controlled trial. Journal of Clinical Medicine. 2026;15(20):7972. Published October 14, 2026. doi:10.3390/jcm15207972. Article (MDPI / JCM)
This post is clinician commentary for educational discussion. It is not medical advice for any reader's personal care. Anesthesia and perioperative decisions should be made with the treating clinician based on the individual patient's circumstances.