Haemodynamics, fluids & transfusion
Cerebral Hemodynamic and Metabolic Responses to Anesthesia and Vasopressors in Adult Shoulder Surgery: A 2 × 2 Factorial Design Randomized Controlled Trial with Light-based Neuromonitoring (CHEM-FACT Study)
Authors' conclusion
This trial found no overall effect of anesthetic or vasopressor choice on rStO 2 or rCMRO 2 during the first 30 min of surgery, suggesting that initial cerebral physiologic responses were comparable across treatment combinations. However, phenylephrine was associated with progressive cerebral desaturation and increasing metabolic demand over time.
Study context
- Population
- Adults undergoing shoulder surgery in the beach chair position, St. Joseph's Hospital (London, Canada), February–November 202439 analysed
- Participants
- 40 adults
- Comparison
- Propofol vs sevoflurane maintenance and phenylephrine infusion vs ephedrine boluses
- Primary endpoint
- Coprimary: relative tissue oxygenation saturation (rStO2) and relative cerebral metabolic rate of oxygen (rCMRO2), by hybrid time-resolved near-infrared spectroscopy and diffuse correlation spectroscopy
- Follow-up
- First 30 min after positioning
Methodological details2 × 2 factorial, Linear mixed-effects models; only first 30 min after positioning analysed
- 2 × 2 factorial
- Linear mixed-effects models; only first 30 min after positioning analysed
Primary result
As reported in the abstract
Average rStO2 and rCMRO2 · 30 min
- No significant main effect of anesthetic or vasopressor choice on average rStO2 or rCMRO2
Further findings
| Outcome | β | P value |
|---|---|---|
| Time by vasopressor interaction, rStO2 · 30 minPhenylephrine vs Ephedrine · 9% greater decline with phenylephrine during 30 min | −0.0014 | P = 0.004 |
| Time by vasopressor interaction, rCMRO2 · 30 minPhenylephrine vs Ephedrine · 70% increase with phenylephrine during 30 min · interaction | 2.2 (95% CI 0.6–3.8) | P = 0.007 |
- Time by vasopressor interaction, rStO2: interaction; χ 2 (1) = 8.4
Temporal change in rStO2 · 30 min
- rStO2 declined over time (β per minute)
- −0.005
- χ 2 (1) = 10.2; P = 0.001
Temporal change in rCMRO2 · 30 min
- rCMRO2 increased over time (β per minute)
- 3.2
- χ 2 (1) = 35.2; P < 0.001
Original publication
Cerebral Hemodynamic and Metabolic Responses to Anesthesia and Vasopressors in Adult Shoulder Surgery: A 2 × 2 Factorial Design Randomized Controlled Trial with Light-based Neuromonitoring (CHEM-FACT Study). Anesthesiology. Published 16 July 2026. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →