Impact of time interval between remifentanil and propofol on propofol injection pain.
OBJECTIVE
To determine the most effective time interval between remifentanil and propofol (TimeRP) for the prevention of propofol injection pain in association with remifentanil dosage.


METHODS
Prospective randomized study.


METHODS
Operating room of a university hospital.


METHODS
Sixty American Society of Anesthesiologists physical status 1 and 2 patients scheduled for elective surgery under general anesthesia.


METHODS
Patients were randomly assigned to 1 of 3 groups to receive remifentanil at dosages of 0.25, 0.5, or 0.75 μg/kg over 30 seconds before the injection of 1% propofol 2 mg/kg. TimeRP was defined as the time interval from the initiation of the remifentanil injection to the initiation of the propofol injection. TimeRP for each subsequent patient was determined by the response of the previous patient using an up-and-down sequential allocation method. Injection pain caused by propofol was evaluated using a 4-point scale during the propofol injection.


METHODS
TimeRP50 was defined as the TimeRP at which propofol injection pain was absent in 50% of patients, and it was estimated using isotonic regression for each dose group.


RESULTS
TimeRP50 was significantly lower in the remifentanil 0.75 μg/kg group (38.6 seconds, 83% confidence interval [CI], 35.6-45.0) than in the 0.5 μg/kg group (65.0 seconds; 83% CI, 52.5-75.0) or the 0.25 μg/kg group (66.6 seconds; 83% CI, 57.1-76.5).


CONCLUSIONS
The efficacy of remifentanil pretreatment for preventing propofol injection pain can be influenced by the time interval between remifentanil and propofol as well as the remifentanil dose.
Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School, Gwangju, South Korea.
Seong Heon
SH
Lee
Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School, Gwangju, South Korea.
Soo Eun
SE
Lee
Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School, Gwangju, South Korea.
Shiyoung
S
Chung
Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School, Gwangju, South Korea.
Hyun Jung
HJ
Lee
Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School, Gwangju, South Korea. Electronic address: anesman@gmail.com.
Seongwook
S
Jeong
D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000768:Anesthesia, General / Q000009:adverse effects* / Q000379:methods; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology / Q000517:prevention & control*; D010147:Pain Measurement; D010880:Piperidines / Q000008:administration & dosage*; D015742:Propofol / Q000008:administration & dosage / Q000009:adverse effects*; D011446:Prospective Studies; D000077208:Remifentanil; D013997:Time Factors
D000701:Analgesics, Opioid; D018686:Anesthetics, Intravenous; D010880:Piperidines; D000077208:Remifentanil; D015742:Propofol
Analgesic; Anesthetic; Opioid; Pain; Propofol; Remifentanil