Low alfentanil target-concentrations improve hemodynamic and intubating conditions during induction with sevoflurane.
OBJECTIVE
To investigate the effects of different alfentanil target-concentrations on hemodynamics, respiration and conditions of tracheal intubation during an inhalation induction with 8% sevoflurane.


METHODS
In this prospective randomized open-label study, 40 ASA I adult patients received alfentanil at the following target-concentrations: zero (Group 0), 25 (Group 25), 50 (Group 50) and 75 ng*mL(-1) (Group 75), starting five minutes before induction of anesthesia with 8% sevoflurane in 50% nitrous oxide. The ease of intubation was determined on fixed criteria and scored; arterial pressure, heart rate and bispectral index (BIS) were recorded at one-minute intervals.


RESULTS
Times to allow tracheal intubation were shortened only in Group 75 (94 +/- 8 sec) as compared to Group 0 (140 +/- 11 sec, P < 0.05). BIS values, tracheal intubation scores and number of attempts were not different between groups. However, more patients suffered from apnea in Group 75. Heart rate and mean arterial pressure remained stable in Group 75 whereas they increased significantly in the three other groups. No patient suffered hypotension.


CONCLUSIONS
Adding alfentanil at a 75 ng*mL(-1) target-concentration during an inhalation induction with 8% sevoflurane in 50% nitrous oxide allows intubation slightly earlier and provides stable hemodynamic conditions but the incidence of apnea during induction is higher. Lower concentrations are of little clinical interest.
Nathan
Nathalie
N
Department of Anesthesia, CHU Dupuytren, Limoges, France. nathan@unilim.fr
Vandroux
David
D
Benrhaiem
Mohammed
M
Marquet
Pierre
P
Preux
Pierre-Marie
PM
Feiss
Pierre
P
D000328:Adult; D015760:Alfentanil / Q000008:administration & dosage / Q000494:pharmacology*; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology; D000704:Analysis of Variance; D018685:Anesthetics, Inhalation / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods*; D008738:Methyl Ethers / Q000627:therapeutic use*; D011446:Prospective Studies; D012018:Reflex / Q000187:drug effects; D000077149:Sevoflurane; D013997:Time Factors
D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D015760:Alfentanil; D000077149:Sevoflurane