Haemodynamics and cerebral oxygenation during arthroscopic shoulder surgery in beach chair position under general anaesthesia
Acta Anaesthesiologica Scandinavica, 05/11/2012

Jeong H et al. – The incidence of jugular desaturation in beach chair position (BCP) was 41%, and P/R anaesthesia and hypotension were associated with its occurrence while undergoing surgery under general anaesthesia. SctO2 may not replace SjvO2 for the determination of cerebral oxygenation.

• Fifty-six consecutive patients undergoing arthroscopic shoulder surgery in BCP were studied.
• Anaesthesia was intravenous with propofol and remifentanil (P/R) or inhalational with sevoflurane and 50% nitrous oxide (S/N) depending on provider choice.
• Mean arterial pressure (MAP), heart rate (HR), SjvO2, and SctO2 were measured before (baseline; post-induction in supine position) and after the patients assumed BCP.
• Bland–Altman analysis was performed to measure the agreement between SctO2 and SjvO2.

• SjvO2, SctO2, MAP, and HR decreased significantly when patients were raised into BCP.
• Jugular desaturation occurred in 41% of patients (56% with P/R vs. 21% with S/N anaesthesia, P=0.0077).
• Risk factors for the desaturation included P/R anaesthesia [adjusted odds ratio (aOR) 4.76, 95% confidence interval (CI) 1.34–16.95, P=0.016] and MAP<50mmHg (aOR 3.85, 95% CI 1.21–12.25, P=0.023).
• Bland–Altman analysis showed a mean difference of -8.9% with 95% limit of agreement between -40.0% and 23.0%.
• The percentage error [1.96 standard deviation/mean of the reference method] was 48.5%.