No reduction in the sufentanil requirement of elderly patients undergoing ventilatory support in the medical intensive care unit

The aim of the study was to test the hypothesis that the requirement of suf entanil is reduced in elderly patients when the opiate is primarily used to facilitate mechanical ventilation in a medical intensive care unit. A furt her aim was to study whether elderly patients developed withdrawal symptoms after discontinuing prolonged sufentanil administration. We have studied p rospectively two groups of patients requiring mechanical ventilation for mo re than 96 h; group 1 age < 60 years (n=316 or 68%) and group 2 age > 70 ye ars (n=150 or 32%). In all patients sufentanil and midazolam were administe red continuously in order to facilitate ventilatory support. After an initi al intravenous bolus injection of sufentanil 3.0-8.0 mu g kg(-1), the dosag e was adjusted to the patients needs (0.75-1.0 mu g(-1) kg(-1) h) using a m odified Ramsey score by accepting between 3b and 4a as the end point. The a mount of sufentanil administered and side effects were recorded at 24-h int ervals. Seventy-two hours following the start of sedation with sufentanil/m idazolam the dose of sufentanil required for sedation increased significant ly (P < 0.05) in both groups when compared with the first 24 h. There was n o statistical difference between the two groups in sufentanil requirement a t any time during the study. This suggests that tachyphylaxis develops to a similar degree in patients in both age groups. In addition, weaning in the elderly was characterized by a similar degree of withdrawal-like symptoms suggesting that independent of age, there are similar receptor related reac tions once the opiate is withdrawn.