Use of remifentanil to reduce propofol injection pain and the required propofol dose in upper digestive tract endoscopy diagnostic tests

Pharmacological control of pain during propofol injection: a systematic review and meta-analysis

OBJECTIVE

A research was performed to review the effect of pharmacological interventions to control the propofol injection pain.

METHODS

A search of databases was performed. Randomized clinical trials comparing pharmacological interventions with placebo or active compound to reduce of propofol injection pain were selected. The outcome was the frequency of pain. Data were analyzed in three subgroups according to type of control. Random effect model was used to calculate relative risk (RR) with 95% confidence intervals (CIs).

RESULTS

Fifty-two articles with 105 studies on 7315 adults were included. The incidence of pain in intervention and control group was 40.91% and 66.27%. Combination therapy with two drugs (RR = 0.29 95% CI = (0.11, 0.75)), opioids (RR = 0.39 95% CI = (0.28, 0.54)) and 5 HT3 antagonists (RR = 0.39 95% CI = (0.30, 0.50)) were the most effective interventions compared to placebo. Combination therapy was the most effective intervention compared to lidocaine as control (RR = 0.51 95% CI = (0.46, 0.55)). Opioids were the most effective intervention compared to long chain triglyceride propofol as control (RR = 0.27 95% CI = (0.15, 0.49)).

CONCLUSION

Pretreatment with two different drugs, opioids and surprisingly 5 HT3 antagonists were the most effective interventions compared to placebo. Combination therapy was the most effective versus lidocaine as control.

Effects of small-dose remifentanil combined with index of consciousness monitoring on gastroscopic polypectomy: a prospective, randomized, single-blinded trial

BACKGROUND

With the development of painless diagnosis and treatment, remifentanil, a synthetic opioid agonist, is increasingly used in gastroscopy for its rapid, short-term, and potent analgesic effect. However, the dosage of remifentanil used in endoscopy is unclear. Index of consciousness (IOC) is a new anesthesia depth-monitoring indicator that can be divided into index of consciousness 1 (IOC₁) and index of consciousness 2 (IOC₂); IOC₁ is used for estimating a patient's sedation state, whereas IOC₂ reflects analgesic depth. We hypothesized that combining with IOC₁ and IOC₂ monitoring may be helpful to identify an optimal remifentanil dosage in gastroscopic polypectomy.

METHODS

One hundred twenty patients scheduled for gastroscopic polypectomy were enrolled and were randomly assigned to remifentanil 2 ng/mL (group R2), 4 ng/mL (group R4), or 6 ng/mL (group R6), and 40 cases were in each group. During the anesthesia period, remifentanil was kept at the initial given concentration but propofol was adjusted according to IOC₁. The primary outcomes were the dosage of propofol and remifentanil. The secondary outcomes were the variety of IOC₁ and IOC₂, patients' awakening time, and peri-operative adverse reactions such as hypotension, hypertension, bradycardia, tachycardia, body movements, hypoxemia, therapy interruption, nausea, vomiting, aspiration, and intra-operative awareness.

RESULTS

With the increasing dosage of remifentanil, the propofol dosage and patients' awakening time decreased significantly, the morbidity of hypertension and body movements also declined, but the incidence of hypotension, bradycardia, and hypoxemia rose. In group R2, the value of IOC₂ remained above 50 during the treatment. However, IOC₂ dropped to below 30 at the beginning of the gastroscopy in group R6, and there was statistical difference in hypoxemia between groups R2 and R6 (P <0.05).

CONCLUSIONS

With the help of IOC monitoring, we found that a target concentration of remifentanil 4 ng/mL is comparatively ideal in patients under gastroscopic polypectomy.

TRIAL REGISTRATION

Chinese Clinical Trial Register: ChiCTR-OOD-16009489 , on October 19, 2016.