title: The potential regimen of target-controlled infusion of propofol in flexible bronchoscopy sedation: a randomized controlled trial.
abstract: OBJECTIVE
  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).
  
  
  CONCLUSIONS
  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.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01101477.
authors: Department of Thoracic Medicine, Chang Gung Memorial Hospital, College of Medicine, Chang Gung University, Taipei, Taiwan.
authors: Ting-Yu
authors: TY
authors: Lin
authors: Yu-Lun
authors: YL
authors: Lo
authors: Chung-Hsing
authors: CH
authors: Hsieh
authors: Yung-Lun
authors: YL
authors: Ni
authors: Tsai-Yu
authors: TY
authors: Wang
authors: Horng-Chyuan
authors: HC
authors: Lin
authors: Chun-Hua
authors: CH
authors: Wang
authors: Chih-Teng
authors: CT
authors: Yu
authors: Han-Pin
authors: HP
authors: Kuo
mesh_terms: D000368:Aged; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D020680:Bronchoscopes / Q000009:adverse effects; D016292:Procedural Sedation / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D007022:Hypotension / Q000209:etiology; D000860:Hypoxia / Q000209:etiology; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D015742:Propofol / Q000008:administration & dosage*
chemical_list: D018686:Anesthetics, Intravenous; D015742:Propofol
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