Overcoming age: Slow anesthesia induction may prevent geriatric patients from developing burst suppression and help developing intraoperative EEG signatures of a younger brain

Elderly patients are prone to develop postoperative neurocognitive deficits potentially precipitated by inadequate anesthetic management. To investigate the potential of EEG-guided individualized anesthetic titration we evaluated the effect of the patient's age on the spectral composition of the EEG during slow propofol induction.

Twenty-six young (<65 years) and 25 old (≥65 years) patients received propofol until loss of responsiveness (LOR). After LOR, we switched from a flow rate-based to a target-controlled infusion mode keeping the calculated effect-site concentration at LOR stable. We recorded a frontal EEG and calculated the power spectral density (PSD) and the band powers. For the comparison of the spectral composition of old and young patients, we used an effect size, the area under the receiver operating characteristic curve.

The older patients received significantly less propofol (p < 0.001). No patient showed a burst suppression pattern. Whereas the absolute power in all frequency bands decreased significantly with the patient's age, the spectral composition did not change throughout the extended induction period.

Slow anesthesia induction may be a suitable approach for geriatric patients to preserve spectral composition patterns typically found in younger brains and to individually identify anesthetic requirements reducing the risk of excessive anesthetic effects.