The potential regimen of target-controlled infusion of propofol in flexible bronchoscopy sedation: a randomized controlled trial.

Abstract

OBJECTIVES:

Target-controlled infusion (TCI) provides precise pharmacokinetic control of propofol concentration in the effect-site (Ce), eg. brain. This pilot study aims to evaluate the feasibility and optimal TCI regimen for flexible bronchoscopy (FB) sedation.

METHODS:

After alfentanil bolus, initial induction Ce of propofol was targeted at 2 μg/ml. Patients were randomized into three titration groups (i.e., by 0.5, 0.2 and 0.1 μg/ml, respectively) to maintain stable sedation levels and vital signs. Adverse events, frequency of adjustments, drug doses, and induction and recovery times were recorded.

RESULTS:

The study was closed early due to significantly severe hypoxemia events (oxyhemoglobin saturation <70%) in the group titrated at 0.5 μg/ml. Forty-nine, 49 and 46 patients were enrolled into the 3 respective groups before study closure. The proportion of patients with hypoxemia events differed significantly between groups (67.3 vs. 46.9 vs. 41.3%, p = 0.027). Hypotension events, induction and recovery time and propofol doses were not different. The Ce of induction differed significantly between groups (2.4±0.5 vs. 2.1±0.4 vs. 2.1±0.3 μg/ml, p = 0.005) and the Ce of procedures was higher at 0.5 μg/ml titration (2.4±0.5 vs. 2.1±0.4 vs. 2.2±0.3 μg/ml, p = 0.006). The adjustment frequency tended to be higher for titration at 0.1 μg/ml but was not statistically significant (2 (0∼6) vs. 3 (0∼6) vs. 3 (0∼11)). Subgroup analysis revealed 14% of all patients required no further adjustment during the whole sedation. Comparing patients requiring at least one adjustment with those who did not, they were observed to have a shorter induction time (87.6±34.9 vs. 226.9±147.9 sec, p<0.001), a smaller induction dose and Ce (32.5±4.1 vs. 56.8±22.7 mg, p<0.001; 1.76±0.17 vs. 2.28 ±0.41, p<0.001, respectively), and less hypoxemia and hypotension (15.8 vs.56.9%, p = 0.001; 0 vs. 24.1%, p = 0.008, respectively).

CONCLUSION:

Titration at 0.5 μg/ml is risky for FB sedation. A subgroup of patients required no more TCI adjustment with fewer complications. Further studies are warranted to determine the optimal regimen of TCI for FB sedation.

TRIAL REGISTRATION:

ClinicalTrials.gov NCT01101477.

• Authors: Ting-Yu Lin, Yu-Lun Lo, Chung-Hsing Hsieh, Yung-Lun Ni, Tsai-Yu Wang, Horng-Chyuan Lin, Chun-Hua Wang, Chih-Teng Yu, Han-Pin Kuo
• Journal: PloS one (PLoS One) Vol. 8 Issue 4 Pg. e62744 ( 2013) ISSN: 1932-6203 [Electronic] United States
• PMID: 23638141 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial)

Chemical References

• Anesthetics, Intravenous
• Propofol

Topics

• Aged
• Anesthetics, Intravenous (administration & dosage)
• Bronchoscopes (adverse effects)
• Conscious Sedation (adverse effects, methods)
• Female
• Humans
• Hypotension (etiology)
• Hypoxia (etiology)
• Infusions, Intravenous
• Male
• Middle Aged
• Outcome Assessment, Health Care
• Propofol (administration & dosage)