Infusion of Propofol to Identify Smallest Effective Doses for Induction of Anaesthesia in Young and Elderly Patients

Abstract

We studied 110 patients older than 60 yr or aged 18-50 yr as separate groups in two stages to identify the smallest effective doses of propofol for induction of anaesthesia. In the elderly patients, in stage 1, at infusion rates of 25, 50 or 100 mg min-1 the mean (SD) doses administered were propofol 0.82 (0.14) mg kg-1, 1.22 (0.24) mg kg-1 and 1.65 (0.60) mg kg-1 and the induction times 140.1 (21.9) s, 103.2 (23.5) s and 69.4 (10.0) s, respectively. In stage 2, after induction with a fixed dose of 0.82 mg kg-1 as a bolus over 5 s or as an infusion at 25 mg min-1, the times for induction were 38.5 (14.0) s and 144.5 (36.6) s, respectively. In the young patients, at induction rates of 33.3, 50, 100 or 200 mg min-1, the doses administered were propofol 1.36 (0.28) mg kg-1, 1.46 (0.12) mg kg-1, 1.85 (0.43) mg kg-1 and 2.39 (0.50) mg kg-1 and the induction times 145.0 (25.4) s, 120.0 (18.4) s, 80.2 (19.2) s and 54.5 (10.4) s, respectively. In stage 2, a fixed induction dose of 1.46 mg kg-1 resulted in induction times of 35.0 (8.5) s and 134.0 (26.8) s, respectively. In stage 2 of each age group, induction was achieved with smaller doses than those recommended previously and there was no difference in the number of patients in whom induction of anaesthesia was successful or in the measured cardiorespiratory variables between the two induction regimens. This suggests the latter effects are caused by the dose administered and not the rate of administration.

Comparison of Dexmedetomidine Versus Ketamine-Propofol Combination for Sedation in Cataract Surgery

“…Yaşlı hastalarda propofole duyarlılığın %30-50 oranında arttığı, midazolamın eliminasyon yarı ömrünün 2 kattan daha fazla uzadığı bildirilmiştir (3,4). Ketaminin ise halüsinojenik etkisinin yaşlılarda bariz olmadı-ğı ve bu nedenle analjezik ve sedatif olarak güvenle kullanıla-bileceği de belirtilmektedir (5).…”

Age Effect on Efficacy and Side Effects of Two Sedation and Analgesia Protocols on Patients Going through Cardioversion: A Randomized Clinical Trial

“…This could be caused by pharmacokinetic differences in medications, medication administration techniques, different dosages, concomitant medications, and the patients' personal habits. 4,11,17,31,32 Goldner et al compared 1 mg/kg propofol bolus with 1 mg of midazolam bolus combined with 1-2 mg of morphine. They found that the average time to reach RSS-5 was 3 (AE2) minutes for propofol and 9 (AE4) minutes for midozolam.…”

“…Studies using propofol for sedation at boluses of 1 and 1.5 mg/kg reported the occurrence of up to 30% apnea and hypotension. 4,13,14,16,20 Fennelly et al compared midazolam plus flumazenil, with midazolam plus placebo. They found excessive desaturation, low arterial blood pressure, and two hours more of sedation in the midazolam plus placebo group.…”

“…32 However, other studies reported that the cardiovascular and respiratory side effects of propofol were independent from the administration technique. 2,4,24,31,32 Peacock et al administered propofol at different infusion rates (25,50, and 100 mg/min) and reported that the induction time was reduced as the medication dosage increased. However, the amount of propofol necessary for a successful procedure increased as well.…”

“…[1][2][3][4][5][6][7][8][9][10] Midazolam and propofol frequently have been used for CV sedation. [11][12][13][14][15][16][17] However, different studies report different application techniques, doses, and side effects, [2][3][4][6][7][8]10,12,15,[18][19][20][21] and data on age-specific efficacy and side effects of midazolam and propofol when used in procedural sedation have been limited. 4,6 This study aimed to compare the efficacy and side effects of slow intermittent bolus injections of midazolam and propofol in patients of two different age groups, younger than 65 years and 65 years and over, who were undergoing CV at Ramsey Sedation Scale level 5 (RSS-5).…”