Susanne Eberl

ANALGESIA WITHOUT SEDATIVES DURING COLONOSCOPIES: WORTH CONSIDERING?

a much faster discharge of patients in the remifentanil group was observed. The necessity

for continuous application and its negative side effects (nausea, vomiting and possible

haemodynamic and respiratory complications) are serious limitations for routine use of

remifentanil. Because only trained users (anaesthesiologists, anaesthesia nurses) would

administer remifentanil, additional staffing costs will be associated with this analgesic

regimen.

Alfentanil

Alfentanil is a µ-receptor opioid that has its maximal effects - comparable to remifentanil -

within 1 to 2 minutes after injection and an elimination half-life of about 100 minutes.

Metabolism takes place in the liver. Only 1% of alfentanil is found non-metabolised in the

urine. Thus, in patients with liver dysfunction a more prolonged and pronounced effect

can be expected. Dose-dependency allows for achieving different levels of awareness,

cooperation, and psychomotor capacity more easily.

The only study addressing the use of alfentanil (10 µg/kg) for colonoscopies as a mono-

drug was performed by Di Palma et al.

The authors compared alfentanil with midazolam/

alfentanil (n=11) and meperidine/midazolam (n=11). Patients receiving alfentanil (n=13)

were less likely to require oxygen supplementation because of desaturation (8 versus 55%

with alfentanil/midazolam and 27% with meperidine/midazolam), and suffered from less

pain. There were no differences in haemodynamics (ECG, NIBP), recovery time, complication

percentage, and patients’ discomfort. Therefore, Di Palma et al. came to the conclusion

that alfentanil alone had no further advantage. However, the safety aspect – significant less

desaturation episodes – makes the substance worth to be examined in more detail.

Usta et al.

compared patient-controlled analgesia (PCA) with alfentanil (mean 1000 µg)

versus fentanyl (mean 80 µg) for colonoscopies. Both opioids were given in combination

with midazolam (group alfentanil: 2.34±0.96 mg, group fentanyl: 2.16±0.9 mg). Worth

mentioning, analgesia was not completely patient-controlled. Patients received a loading

dose of 500 µg alfentanil and were asked to request a further bolus (by pushing the button),

when they felt pain. If sedation score exceeded 3 (OAA/S), further midazolam was added.

Patients within both groups showed the same satisfaction score after colonoscopy andwere

disposed to undergo colonoscopy again. No adverse events (e.g. respiratory depression,

haemodynamic changes) were observed. As expected, recovery was significantly shorter

with the use of alfentanil compared to fentanyl. The author’s conclusion focussed on

alfentanil, although midazolam was also administered as a sedative agent.

No other studies addressed the use of alfentanil for colonoscopies. In neurosurgical patients

undergoing stereotactic brain biopsy, Bilgin et al.

compared the effects of alfentanil,

fentanyl, and remifentanil analgo-sedation combined with midazolam on haemodynamic

and respiratory parameters. Alfentanil (10 µg/kg) initially led to a reduction in minute