Less adrenergic activation during cataract surgery with total intravenous than with local anesthesia

Previous studies reported that, contrary to local anesthesia, cataract surgery under inhalational anesthesia is associated with substantial adrenergic activation. We tested the hypothesis that total intravenous anesthesia (TIVA) with propofol and alfentanil produces less or comparable adrenergic activation during cataract surgery than local anesthesia.

Patients were randomly assigned to peribulbar local block (n=10) or TIVA (n=10). The heart rate, blood pressure, plasma concentrations of catecholamines, cortisol, and glucose were assessed at seven pre-, intra-, and post-operative time points.

In the patients given local anesthesia, plasma concentrations of epinephrine, norepinephrine and cortisol did not change significantly. In contrast, plasma epinephrine decreased by roughly 66% during TIVA: from 45+/-16 to 15+/-8 pg/ml. Plasma norepinephrine concentration decreased by roughly 50%, from 462+/-265 to a minimum value of 219+/-6 pg/ml and plasma cortisol concentrations decreased by roughly 61%, from 16.4 ng/ml to 6.4 ng/ml. Blood pressure and heart rates remained near baseline values during local anesthesia. In contrast, systolic blood pressure decreased by 30% and heart rate by 12 beats/min during TIVA.

The presented study and available data clearly suggest that local anesthesia produces the best adrenergic and hemodynamic stability during cataract surgery. Contrary to previously reported results on inhalational anesthesia (thiopentone/enflurane), the TIVA regimen used effectively prevents the adrenergic and metabolic response during cataract surgery.