Comparison of Monitored Anesthesia Care Using Remifentanil or Fentanyl for Major Dressing Changes in Burns
Status:
Terminated
Trial end date:
2006-09-01
Target enrollment:
Participant gender:
Summary
During their hospitalization, burn patients frequently require dressing changes that may be
painful. Deep analgesia and sedation are used but carry the risk of remnant somnolence and
other effects of anesthesia such as dizziness and nausea/vomiting. All these side effects may
delay refeeding after the procedure, ambulation and physical therapy. Drugs from the opioid
class are used to relieve pain during these procedures. Morphine with its slow onset and
remnant sedation is difficult to use in these patients. Pro-emetic properties and histamine
liberating effects also make this drug non optimal for iterative procedures. Fentanyl, a
synthetic opioid with shorter onset and lower incidence of nausea and vomiting, is the
standard drug used in dressing changes in burn patients. It is metabolized by hepatic
glucoconjugation. Remifentanil, a well known novel opioid, that has a unique metabolism
independent from renal or hepatic functions, is metabolized by a non specific esterase. It
has a very short half-life (3.5 minutes) and should therefore be administered as a continuous
infusion. The investigators hypothesized that the use of remifentanil for daily burn dressing
changes is associated with less pain during procedures and faster recovery. Studied patients
will be the ones requiring iterative dressing change procedures under sedation. The primary
endpoint will be the maximal pain during the procedure. Secondary endpoints will be: average
pain during and after the procedure; subjective sensation of comfort; total amount of opioids
received; times to feeding after the procedure and ambulation after the procedure; comfort of
the procedure according to the nurses; mobilisation according to the physical therapist; and
safety of the analgesia technique. The study will be conducted according to the
recommendations of the American Society of Anesthesiologists (ASA) that have been endorsed by
the Canadian Anaesthetists' Society (CAS). All patients who consent will fast for at least 6
hours before the procedure. The two following regimens will be compared: a bolus infusion of
fentanyl, starting with 1 µg/kg, followed by 0.5 µg/kg as needed every 5 to 10 minutes versus
continuous infusion of remifentanil adapted to ensure analgesia. The initial dose of
remifentanil will be 0.1 µg/kg/min to be adjusted between 0.05 µg/kg/min and 2 µg/kg/min. To
allow blinding during the study, patients will receive a double-blinded protocol with sham
(normal saline) in one arm. In other words: for each procedure, the patient will always
receive boluses, either of fentanyl or saline, and a perfusion, either of remifentanil or
saline. According to power calculations, 30 patients will be necessary to achieve the primary
end-points. The investigators plan to enroll 40 patients in the study to allow for some drop
outs and to increase their statistical power.