Total intravenous anesthesia using remifentanil in extracorporeal shock wave lithotripsy (ESWL). Comparison of two dosages: a randomized clinical trial.

BACKGROUND: Extracorporeal Shock Wave Lithotripsy is usually performed in day surgery setting, consequently people who undergo to this procedure need a safe and fast recovery. Conscious sedation with remifentanil can relieve from pain and keep patients in touch with anaesthesiologists. Few publications tell about infusion rates administered to perform this procedure7. The aim of this study is to assess which is the most appropriate infusion rate. METHODS: Patients were randomly assigned to two groups. Two different infusion rates were compared: 0,05 mcg/kg/min, GROUP A (N.=114), vs. 0.1 µg/kg/min, GROUP B (N.=114). Patients' vital signs, additional analgesic requests, PONV (postoperative nausea and vomiting) and other side effects were registered. The deepness of sedation and patient's satisfaction were evaluated referring to Obsever's Assessment of Alertness and Sedation scale (O/ASS) and using a Likert's scale respectively. Pain intensity was assessed with a 11-points VAS (visual analogue scale). Differences between groups were analyzed using Student t test for independent variables. The χ2 test was used to analyze categorical variables. RESULTS: The study enrolled 228 patients and assigned them to two groups (N.=114). No significant differences were found regarding Likert's scale values (P=0.20), additional analgesic request (P=0.30) and mean VAS values (P>0.05) between the two groups. The difference between the two groups about PONV, hypotension, oxygen desaturation and respiratory depression was statistically significant (P<0.05), as a matter of fact in group A these side effects occurred less frequently. The fifth degree of O/ASS was estimated in about 1.61±0.19 min and 2.987±0.20 min in group A and in group B respectively (P<0.05). CONCLUSION: According with previous results remifentanil at the infusion rate of 0.05 µg/kg/min provides an effective analgesia, causing a lower incidence of side effect than 0.1 µg/kg/min, granting a fast and safe recovery.

Safety and efficacy of transdermal buprenorphine and transdermal fentanyl in the treatment of neuropathic pain in AIDS patients.

BACKGROUND: Multifactor neuropathic pain is one of the most frequent symptoms in AIDS patients and analgesic treatment is primarily based on the use of drug combination of opioids, tricyclic antidepressants and antiepileptics. However, the chronic use of opioids in AIDS patients presents a risk due to the immunosuppressive action of these drugs. Until now, buprenorphine has been regarded as one of the safest opioid analgesics for the treatment of patients with compromised immune systems. To assess the suitability of transdermal fentanyl for the treatment of neuropathic pain in AIDS patients, the present study compares the efficacy, tolerability and the immunosuppressive effects of transdermal buprenorphine vs. fentanyl. METHODS: Forty advanced AIDS patients (28 male and 12 female) with chronic peripheral neuropathic pain were enrolled onto this clinical trial. Neuropathic pain was assessed for its constituent types of pain (burning, stabbing and shooting), its overall intensity and allodynia; scores were awarded using the Neuropathic Pain Scale, expressed as 10 item VAS scores. RESULTS: Both treatment groups showed statistically significant reductions in each of the individual types of neuropathic pain and allodynia (P<0.05; 95% CI: -14.7, -3.1) and significant improvements in Karnofsky Performance Status (P<0.05; mean value, 69; range: 40-90). Both buprenorphine and fentanyl were well tolerated. Neither buprenorphine nor fentanyl affected CD4+ or CD8+levels and both treatments, but particularly buprenorphine group, resulted in more stable CD4+ concentrations. CONCLUSION: The high efficacy, tolerability and patient compliance of both buprenorphine and fentanyl make both these two opioids valid therapeutic options for the treatment of neuropathic pain in patients with AIDS.