Comparison of Dexmedetomidine and Fentanyl as an Adjuvant to Ropivacaine for Postoperative Epidural Analgesia in Pediatric Orthopedic Surgery

PURPOSE: Opioids are commonly used as an epidural adjuvant to local anesthetics, but are associated with potentially serious side effects, such as respiratory depression. The aim of this study was to compare the efficacy and safety of dexmedetomidine with that of fentanyl as an adjuvant to epidural ropivacaine in pediatric orthopedic surgery. MATERIALS AND METHODS: This study enrolled 60 children (3–12 years old) scheduled for orthopedic surgery of the lower extremities and lumbar epidural patient-controlled analgesia (PCA). Children received either dexmedetomidine (1 µg/kg) or fentanyl (1 µg/kg) along with 0.2% ropivacaine (0.2 mL/kg) via an epidural catheter at 30 minutes before the end of surgery. Postoperatively, the children were observed for ropivacaine consumption via epidural PCA, postoperative pain intensity, need for rescue analgesics, emergence agitation, and other adverse effects. RESULTS: The mean dose of bolus epidural ropivacaine was significantly lower within the first 6 h after surgery in the dexmedetomidine group, compared with the fentanyl group (0.029±0.030 mg/kg/h vs. 0.053±0.039 mg/kg/h, p=0.012). The median pain score at postoperative 6 h was also lower in the dexmedetomidine group, compared to the fentanyl group [0 (0–1.0) vs. 1.0 (0–3.0), p=0.039]. However, there was no difference in the need for rescue analgesia throughout the study period between groups. CONCLUSION: The use of dexmedetomidine as an epidural adjuvant had a significantly greater analgesic and local anesthetic-sparing effect, compared to fentanyl, in the early postoperative period in children undergoing major orthopedic lower extremity surgery.

Efficacy of Palonosetron vs. Ramosetron for the Prevention of Postoperative Nausea and Vomiting: A Meta-Analysis of Randomized Controlled Trials

PURPOSE: This study was designed as a meta-analysis of randomized controlled trials (RCTs) that included the comparison of palonosetron and ramosetron for postoperative nausea and vomiting (PONV) prophylaxis. MATERIALS AND METHODS: A systematic search was conducted for the PubMed, EMBASE, Web of Science, CENTRAL, KoreaMed, and Google Scholar databases (PROSPERO protocol number CRD42015026009). Primary outcomes were the incidences of postoperative nausea (PON) and postoperative vomiting (POV) during the first 48 hrs after surgery. The total 48-hr period was further analyzed in time epochs of 0–6 hrs (early), 6–24 hrs (late), and 24–48 hrs (delayed). Subgroup analyses according to number of risk factors, sex, and type of surgery were also performed. RESULTS: Eleven studies including 1373 patients were analyzed. There was no difference in PON or POV between the two drugs for the total 48-hr period after surgery. However, palonosetron was more effective in preventing POV during the delayed period overall [relative risk (RR), 0.59; 95% confidence interval (CI), 0.39 to 0.89; p=0.013], as well as after subgroup analyses for females and laparoscopies (RR, 0.56; 95% CI, 0.36 to 0.86; p=0.009 and RR, 0.46; 95% CI, 0.23 to 0.94; p=0.033). Subgroup analysis for spine surgery showed that ramosetron was more effective in reducing POV during the total 48-hr (RR, 3.34; 95% CI, 1.46 to 7.63; p=0.004) and early periods (RR, 8.47; 95% CI, 1.57 to 45.72; p=0.013). CONCLUSION: This meta-analysis discovered no definite difference in PONV prevention between the two drugs. The significant findings that were seen in different time epochs and subgroup analyses should be confirmed in future RCTs.

Effect of Pneumoperitoneum on Oxidative Stress and Inflammation via the Arginase Pathway in Rats

PURPOSE: Oxidative stress during CO2 pneumoperitoneum is reported to be associated with decreased bioactivity of nitric oxide (NO). However, the changes in endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and arginase during CO2 pneumoperitoneum have not been elucidated. MATERIALS AND METHODS: Thirty male Sprague-Dawley rats were randomized into three groups. After anesthesia induction, the abdominal cavities of the rats of groups intra-abdominal pressure (IAP)-10 and IAP-20 were insufflated with CO2 at pressures of 10 mm Hg and 20 mm Hg, respectively, for 2 hours. The rats of group IAP-0 were not insufflated. After deflation, plasma NO was measured, while protein expression levels and activity of eNOS, iNOS, arginase (Arg) I, and Arg II were analyzed with aorta and lung tissue samples. RESULTS: Plasma nitrite concentration and eNOS expression were significantly suppressed in groups IAP-10 and IAP-20 compared to IAP-0. While expression of iNOS and Arg I were comparable between the three groups, Arg II expression was significantly greater in group IAP-20 than in group IAP-0. Activity of eNOS was significantly lower in groups IAP-10 and IAP-20 than in group IAP-0, while iNOS activity was significantly greater in group IAP-20 than in groups IAP-0 and IAP-10. Arginase activity was significantly greater in group IAP-20 than in groups IAP-0 and IAP-10. CONCLUSION: The activity of eNOS decreases during CO2 pneumoperitoneum, while iNOS activity is significantly increased, a change that contributes to increased oxidative stress and inflammation. Moreover, arginase expression and activity is increased during CO2 pneumoperitoneum, which seems to act inversely to the NO system.

Pharmacodynamic Estimate of Propofol-Induced Sedation and Airway Obstruction Effects in Obstructive Sleep Apnea-Hypopnea Syndrome

PURPOSE: Sedatives must be carefully titrated for patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) as oversedation may lead to disastrous respiratory outcomes. This study aimed to investigate the relations between the effect-site concentration (Ce) of propofol and sedation and airway obstruction levels in patients with OSAHS. MATERIALS AND METHODS: In 25 patients with OSAHS, sedation was induced by 2% propofol using target-controlled infusion. Sedation and airway obstruction levels were assessed using the Observer's Assessment of Alertness/Sedation Scale and a four-category scale, respectively. The relationships between propofol Ce and sedation and airway obstruction were evaluated using a sigmoid Emax model. Pharmacodynamic modeling incorporating covariates was performed using the Nonlinear Mixed Effects Modeling VII software. RESULTS: Increased propofol Ce correlated with the depth of sedation and the severity of airway obstruction. Predicted Ce50(m) (Ce associated with 50% probability of an effect> or =m) for sedation scores (m> or =2, 3, 4, and 5) and airway-obstruction scores (m> or =2, 3, and 4) were 1.61, 1.78, 1.91, and 2.17 microg/mL and 1.53, 1.64, and 2.09 microg/mL, respectively. Including the apnea-hypopnea index (AHI) as a covariate in the analysis of Ce50(4) for airway obstruction significantly improved the performance of the basic model (p<0.05). CONCLUSION: The probability of each sedation and airway obstruction score was properly described using a sigmoid Emax model with a narrow therapeutic range of propofol Ce in OSAHS patients. Patients with high AHI values need close monitoring to ensure that airway patency is maintained during propofol sedation.

Finding the 'Ideal' Regimen for Fentanyl-Based Intravenous Patient-Controlled Analgesia: How to Give and What to Mix?

PURPOSE: This analysis was done to investigate the optimal regimen for fentanyl-based intravenous patient-controlled analgesia (IV-PCA) by finding a safe and effective background infusion rate and assessing the effect of adding adjuvant drugs to the PCA regimen. MATERIALS AND METHODS: Background infusion rate of fentanyl, type of adjuvant analgesic and/or antiemetic that was added to the IV-PCA, and patients that required rescue analgesics and/or antiemetics were retrospectively reviewed in 1827 patients who underwent laparoscopic abdominal surgery at a single tertiary hospital. RESULTS: Upon multivariate analysis, lower background infusion rates, younger age, and IV-PCA without adjuvant analgesics were identified as independent risk factors of rescue analgesic administration. Higher background infusion rates, female gender, and IV-PCA without additional 5HT3 receptor blockers were identified as risk factors of rescue antiemetics administration. A background infusion rate of 0.38 microg/kg/hr [area under the curve (AUC) 0.638] or lower required rescue analgesics in general, whereas, addition of adjuvant analgesics decreased the rate to 0.37 microg/kg/hr (AUC 0.712) or lower. A background infusion rate of 0.36 microg/kg/hr (AUC 0.638) or higher was found to require rescue antiemetics in general, whereas, mixing antiemetics with IV-PCA increased the rate to 0.37 microg/kg/hr (AUC 0.651) or higher. CONCLUSION: Background infusion rates of fentanyl between 0.12 and 0.67 microg/kg/hr may safely be used without any serious side effects for IV-PCA. In order to approach the most reasonable background infusion rate for effective analgesia without increasing postoperative nausea and vomiting, adding an adjuvant analgesic and an antiemetic should always be considered.

Percutaneous cardiopulmonary support to treat suspected venous air embolism with cardiac arrest during open eye surgery: a case report / 대한마취과학회지

We report a case of possible venous air embolism (VAE) during trans pars plana vitrectomy with air-fluid exchange of the vitreous cavity. Shortly after initiation of air-fluid exchange, decreases in end-tidal CO2, oxygen saturation, and blood pressure were observed. The patient rapidly progressed to cardiac arrest unresponsive to cardiopulmonary resuscitation, and recovered after the application of percutaneous cardiopulmonary support. Prompt termination of air infusion is needed when VAE is suspected during air-fluid exchange, and extracorporeal life support should be considered in fatal cases. Although the incidence is rare the possibility of VAE during ophthalmic surgery clearly exists, and therefore awareness and vigilant monitoring seem critical.

Tethered spinal cord syndrome detected during ultrasound for caudal block in a child with single urological anomaly / 대한마취과학회지

No abstract available.

Apnea and unconsciousness after accidental subdural placement of an epidural catheter / 대한마취과학회지

No abstract available.

Total Intravenous Anesthesia with Propofol Reduces Postoperative Nausea and Vomiting in Patients Undergoing Robot-Assisted Laparoscopic Radical Prostatectomy: A Prospective Randomized Trial

PURPOSE: We investigated the effect of total intravenous anesthesia (TIVA) with propofol on postoperative nausea and vomiting (PONV) after robot-assisted laparoscopic radical prostatectomy (RLRP) in patients at low risk of developing PONV, in comparison to balanced anesthesia with desflurane. MATERIALS AND METHODS: Sixty two patients were randomly assigned to the Des or TIVA group. Propofol and remifentanil were used for induction of anesthesia in both groups and for maintenance of the anesthesia in the TIVA group. In the Des group, anesthesia was maintained with desflurane and remifentanil. In both groups, postoperative pain was controlled using fentanyl-based intravenous patient controlled analgesia, and ramosetron 0.3 mg was administered at the end of surgery. The incidence of PONV, severity of nausea and pain, and requirements of rescue antiemetics and analgesics were recorded. RESULTS: The incidence of nausea in the post-anesthetic care unit was 22.6% in the Des group and 6.5% in the TIVA (p=0.001) group. The incidence of nausea at postoperative 1-6 hours was 54.8% in the Des group and 16.1% in the TIVA group (p=0.001). At postoperative 6-48 hours, there were no significant differences in the incidence of nausea between groups. CONCLUSION: In order to prevent PONV after RLRP in the early postoperative period, anesthesia using TIVA with propofol is required regardless of patient-related risk factors.