• Journal: British Journal of Anaesthesia

• PMID: 37474241

• Type of study: Randomized, controlled trial

• Hypothesis

  • There is less delirium after propofol-based than after sevoflurane-based anaesthesia within 7 days of major cancer surgery

• Methods

  • 1228 subjects

    • Multicenter

    • All centers in China

  • Inclusion criteria

    • Ages 65-90 

    • Primary solid organ cancer, not previously treated with chemo or radiation

    • Surgeries expected to last > 2 hours under GA

  • Exclusion criteria

    • Schizophrenia, epilepsy, PD, MG, pre-existing cognitive dysfunction/dementia/language barrier/AMS

    • ASA 4 

    • Severe hepatic dysfunction or preop dialysis

  • Patients randomized to sevoflurane-based or propofol-based groups

    • Intraop management

      • No premedication

      • Induction 

        • Midazolam

        • Sufentanil or remifentanil

        • Propofol or etomidate

        • Rocuronium or cisatracurium

      • Maintenance with propofol infusion or sevoflurane

      • No nitrous oxide used

      • BIS target 40-60

      • BP goal - 80% of baseline

      • Post-op analgesia with morphine or sufentanil PCA

      • No scopolamine and penehyclidine for PONV

      • No peripheral nerve blocks, no dexmedetomidine. 

• Results

  • Primary outcome

    • Incidence of delirium within 7 days post-op

      • Propofol group (8.4%) vs sevoflurane group (12.4%)

        • RR 0.68 [95% CI: 0.48-0.95]; p =0.023

        • NNT 25 [95% CI: 13-176]

      • Greatest difference seen on POD1

    • No clinically meaningful differences between methadone groups and control

  • Secondary outcomes

    • No significant differences seen on:

      • ICU admission/ICU length of stay

      • Postop mechanical ventilation

      • Hospital LOS

      • Cognitive function at 30 days postop

• Strengths

  • Multicenter RCT

  • Blinding (subjects, investigators, other clinicians) except anesthesia providers

  • Pre-op variables comparable

  • Exclusion criteria appropriate

  • Prop group experienced more stressful surgeries but less post-op delirium 

• Weaknesses

  • All subjects from China

  • Majority ASA 2, avg BMI 23

  • Only analyzed major cancer surgery 

  • Surgeries long (> at least 2 hours)

  • Postop analgesia PCA-based/no PNBs used

  • Fragile results

• Key Point: Subjects randomized to propofol-based general anesthesia had 1/3 less postoperative delirium as compared to those receiving sevoflurane-based anesthesia.

Br J Anaesth. 2023 Aug;131(2):253-265