Suzana Müller

Clinical efficacy of dexmedetomidine alone is less than propofol for conscious sedation during ERCP

BACKGROUND Propofol is an accepted method of sedation for an ERCP and generally achieves deep sedation rather than conscious sedation, and dexmedetomidine has sedative properties of equivalent efficacy. OBJECTIVE To examine the hypothesis that dexmedetomidine is as effective as propofol combined with fentanyl for providing conscious sedation during an ERCP. DESIGN AND SETTING Randomized, blind, double-dummy clinical trial. PATIENTS Twenty-six adults, American Society of Anesthesiologists status I to III, underwent an ERCP. INTERVENTIONS Patients were randomized to receive either propofol (n = 14) (target plasma concentration range 2-4 microg/mL) combined with fentanyl 1 microg/kg, or dexmedetomidine (n = 12) 1 microg/kg for 10 minutes, followed by 0.2 to 0.5 microg/kg/min. Additional sedatives were used if adequate sedation was not achieved at the maximum dose allowed. MAIN OUTCOMES MEASUREMENTS The sedation level was assessed by the Richmond alertness-sedation scale and the demand for additional sedatives. Furthermore, heart rate, blood pressure, oxygen saturation, and respiratory rate were continuously assessed. RESULTS The relative risk (RR) was 2.71 (95% CI, 1.31-5.61) and the number of patients that needed to be treated (NNT) was 1.85 (95% CI, 1.19-4.21) to observe one additional patient with drowsiness 15 minutes after sedation in the dexmedetomidine group. Also, the RR was 9.42 (95% CI, 1.41-62.80), and the NNT was 1.42 (95% CI, 1.0-2.29) to require additional analgesic. However, there was also a greater reduction in blood pressure, a lower heart rate, and greater sedation after the procedure. CONCLUSIONS Dexmedetomidine alone was not as effective as propofol combined with fentanyl for providing conscious sedation during an ERCP. Furthermore, dexmedetomidine was associated with greater hemodynamic instability and a prolonged recovery.

Neuroplastic Effects of Transcranial Direct Current Stimulation on Painful Symptoms Reduction in Chronic Hepatitis C: A Phase II Randomized, Double Blind, Sham Controlled Trial

Introduction: Pegylated Interferon Alpha (Peg-IFN) in combination with other drugs is the standard treatment for chronic hepatitis C infection (HCV) and is related to severe painful symptoms. The aim of this study was access the efficacy of transcranial direct current stimulation (tDCS) in controlling the painful symptoms related to Peg-IFN side effects. Materials and Methods: In this phase II double-blind trial, twenty eight (n = 28) HCV subjects were randomized to receive either 5 consecutive days of active tDCS (n = 14) or sham (n = 14) during 5 consecutive days with anodal stimulation over the primary motor cortex region using 2 mA for 20 min. The primary outcomes were visual analogue scale (VAS) pain and brain-derived neurotrophic factor (BDNF) serum levels. Secondary outcomes were the pressure-pain threshold (PPT), the Brazilian Profile of Chronic Pain: Screen (B-PCP:S), and drug analgesics use. Results: tDCS reduced the VAS scores (P < 0.003), with a mean pain drop of 56% (p < 0.001). Furthermore, tDCS was able to enhance BDNF levels (p < 0.01). The mean increase was 37.48% in the active group. Finally, tDCS raised PPT (p < 0.001) and reduced the B-PCP:S scores and analgesic use (p < 0.05). Conclusions: Five sessions of tDCS were effective in reducing the painful symptoms in HCV patients undergoing Peg-IFN treatment. These findings support the efficacy of tDCS as a promising therapeutic tool to improve the tolerance of the side effects related to the use of Peg-IFN. Future larger studies (phase III and IV trials) are needed to confirm the clinical use of the therapeutic effects of tDCS in such condition. Trial registration: Brazilian Human Health Regulator for Research with the approval number CAAE 07802012.0.0000.5327.

Predictive factors of oxygen desaturation of patients submitted to endoscopic retrograde cholangiopancreatography under conscious sedation

BACKGROUND AND AIMS Hypoxemia can occur during endoscopic retrograde cholangiopancreatography probably induced by the analgesia and sedation done. Moreover the patients prone position difficults the adequate ventilation. The hypoxemia and hypoventilation may not be noticed by nursing staff. A transversal study was used to investigate possible predictive factors of oxygen desaturation in sedated patients with midazolam associated to meperidine undergoing endoscopic retrograde cholangiopancreatography. PATIENTS AND METHODS A total of 186 patients were monitored with continuous pulse oximetry. Poisson regression was used to measure the independent effect of each factor adjusted for effects of each of the other factors. The variables studied were: age, gender, hematocrit and hemoglobin levels, scopolamine use, diagnostic or therapeutic exam, American Society of Anesthesiologists Scores (ASA), duration time of exam, sedative used midazolam in the average of 0.07 mg/kg and analgesic drug meperidine in the average of 0.7 mg/kg that was titrated according patients reaction. RESULTS No desaturation was found in 113 (60.8%) patients, mild desaturation (SpO2 <92%) in 22 (11.8%) and severe desaturation (SpO2 <90%) in 51 (27.4%). This desaturation was recognized only by the pulse oximeter. There was no need to use any antagonist drug of the sedatives in patients who had severe desaturation, they were just stimulated to deep breaths and oxygen was offered at 2 liters per minute via catheter. The variables found to predict desaturation were age >60 years old and ASA score III. The duration of exam was barely significant for desaturation. CONCLUSIONS The variables of age of 60 years old or more, and ASA III score are identified as increased risk for desaturation for patients who undergo endoscopic retrograde cholangiopancreatography under conscious sedation. Long time of exam suggests the patient oxygen desaturate. Such patients require very close monitoring to desaturation and hypoventilation by the assistants and nursing staff alerting to respiratory depression. The use of pulse oximeter and asking for deep breaths during the exam helps to diminish such risks.

Randomized clinical trial comparing sodium picosulfate with mannitol on the preparation FOR colonoscopy in hospitalized patients

BACKGROUND The cleansing of the colon for a colonoscopy exam must be complete so as to allow the visualization and inspection of the intestinal lumen. The ideal cleansing agent should be easily administered, have a low cost, and minimum collateral effects. Sodium picosulfate together with the magnesium citrate is a cathartic stimulant and mannitol is an osmotic laxative, both usually used for this purpose. AIMS Assess the colon cleanliness comparing the use of mannitol and sodium picosulfate as well as evaluate the level of patient satisfaction, the presence of foam, pain, and abdominal distension in hospitalized patients undergoing colonoscopy. METHODS A prospective, randomized, single-blind study with 80 patients that compared two groups: mannitol (40) and sodium picosulfate (40). Both groups received the same dietary orientation. The study was approved by the hospitals Ethics and Research Committee. The endoscopist was blind to the type of preparation. Outcomes evaluated: level of the colons cleanliness, patients satisfaction, the presence of foam, abdominal pain and distension, and the duration of the exam. The data was analyzed by means of the chi-squared test for proportions and Mann-Whitney for independent samples. RESULTS There were no statistically significant differences between the groups in relation to the level of the colons cleanliness, patients satisfaction, the presence of foam, abdominal pain, and the duration of the exam. Fifteen percent of the exams of the mannitol group were interrupted while from the sodium picosulfate group it was 5%. The presence of foam was similar for both groups. The average duration for carrying out the exam was 28.44 minutes for the mannitol group and 35.59 minutes for the sodium picosulfate group. Abdominal distension was more frequent in the mannitol group. If they would have to do the same exam, the answer was that 80% said yes from the mannitol group and 92.5% from the sodium picosulfate group. CONCLUSION The quality of the colon preparation, foam formation, exam duration, and the collateral effects (nauseas, vomiting, and abdominal pain) were similar in both kinds of preparations. Abdominal distension was greater in the mannitol group. Both methods of preparation were well accepted by the hospitalized patients.

A Phase II, Randomized, Double-Blind, Placebo Controlled, Dose-Response Trial of the Melatonin Effect on the Pain Threshold of Healthy Subjects

Background Previous studies have suggested that melatonin may produce antinociception through peripheral and central mechanisms. Based on the preliminary encouraging results of studies of the effects of melatonin on pain modulation, the important question has been raised of whether there is a dose relationship in humans of melatonin on pain modulation. Objective The objective was to evaluate the analgesic dose response of the effects of melatonin on pressure and heat pain threshold and tolerance and the sedative effects. Methods Sixty-one healthy subjects aged 19 to 47 y were randomized into one of four groups: placebo, 0.05 mg/kg sublingual melatonin, 0.15 mg/kg sublingual melatonin or 0.25 mg/kg sublingual melatonin. We determine the pressure pain threshold (PPT) and the pressure pain tolerance (PPTo). Quantitative sensory testing (QST) was used to measure the heat pain threshold (HPT) and the heat pain tolerance (HPTo). Sedation was assessed with a visual analogue scale and bispectral analysis. Results Serum plasma melatonin levels were directly proportional to the melatonin doses given to each subject. We observed a significant effect associated with dose group. Post hoc analysis indicated significant differences between the placebo vs. the intermediate (0.15 mg/kg) and the highest (0.25 mg/kg) melatonin doses for all pain threshold and sedation level tests. A linear regression model indicated a significant association between the serum melatonin concentrations and changes in pain threshold and pain tolerance (R2 = 0.492 for HPT, R2 = 0.538 for PPT, R2 = 0.558 for HPTo and R2 = 0.584 for PPTo). Conclusions The present data indicate that sublingual melatonin exerts well-defined dose-dependent antinociceptive activity. There is a correlation between the plasma melatonin drug concentration and acute changes in the pain threshold. These results provide additional support for the investigation of melatonin as an analgesic agent. Brazilian Clinical Trials Registry (ReBec): (U1111-1123-5109). IRB: Research Ethics Committee at the Hospital de Clínicas de Porto Alegre.