Cerebral oxygenation when ventilated or spontaneously breathing: a randomised control trial

Area of Science:

• Anesthesiology
• Neurosurgery
• Critical Care Medicine

Background:

• Cerebral oxygenation is critical during beach chair shoulder surgery, as cerebral desaturation can lead to serious complications.
• No prior randomized controlled trials have compared spontaneous ventilation and intermittent positive pressure ventilation (IPPV) regarding their effects on cerebral oximetry.

Purpose of the Study:

• To investigate the impact of spontaneous ventilation versus IPPV on intraoperative cerebral oxygenation during arthroscopic shoulder surgery.
• To compare the incidence of cerebral desaturation events between the two ventilatory strategies.

Main Methods:

• A randomized controlled trial involving 40 patients undergoing arthroscopic shoulder surgery.
• Patients were randomized to either spontaneous breathing or IPPV, with standardized anesthetic care.
• Cerebral oxygenation was measured using oximetry, with anesthesiologists blinded to the data. Primary outcome: time-averaged change in cerebral oxygenation; Secondary outcome: cerebral desaturation events (≥20% fall or ≤55% absolute value).

Main Results:

• No statistically significant difference in the time-averaged change in cerebral oxygenation between spontaneously breathing patients and those receiving IPPV (p=0.332 for left hemisphere, p=0.427 for right hemisphere).
• Three cerebral desaturation events occurred in the spontaneous ventilation group and eight in the IPPV group (p=0.155).

Conclusions:

• The choice of ventilatory strategy (spontaneous ventilation vs. IPPV) did not significantly affect cerebral oxygenation in patients undergoing shoulder surgery in the beach chair position.
• Further research may be needed to explore other factors influencing cerebral oxygenation in this surgical setting.