Ultrasound-Assisted Mental Nerve Block and Pulsed Radiofrequency Treatment for Intractable Postherpetic Neuralgia: Three Case Studies

Postherpetic neuralgia (PHN) is one of the most difficult pain syndromes to treat. Invasive treatments may be considered when patients fail to obtain adequate pain relief from noninvasive treatment approaches. Here, we present three cases of PHN in the mandibular branch treated with ultrasound-assisted mental nerve block and pulsed radiofrequency treatment. None of the patients had adequate pain relief from the medical therapy, so we performed the mental nerve block on the affected side under ultrasound assistance. Two patients showed satisfactory pain relief continuously over 12 months without any further interventions, whereas one patient only had short-term pain relief. For the patient had short-term pain relief we performed pulsed radiofrequency treatment (PRFT) on the left mental nerve under ultrasound assistance. After PRFT, the patient had adequate pain relief for 6 months and there was no need for further management.

Effect-site concentration of remifentanil for blunting hemodynamic responses to tracheal intubation using light wand during target controlled infusion-total intravenous anesthesia / 대한마취과학회지

BACKGROUND: Transillumination using a light wand is an alternative type of laryngoscope used for tracheal intubation. There is little information available on the effect-site concentration of remifentanil required to control hemodynamic changes induced by tracheal intubation using the transillumination method during total IV anesthesia. We therefore conducted this study to determine the effect-site concentration of remifentanil blunting hemodynamic responses after tracheal intubation in patients receiving propofol anesthesia. METHODS: We enrolled 26 healthy adult patients (ASA physical status I-II), aged 16-67 scheduled for surgery within 2 hours. All patients received a target-controlled infusion of 4 microg/ml propofol. The effect-site target-concentration of remifentanil of 5.0 ng/ml was chosen for the first patient. We used the Dixon's up-and-down sequential allocation method for determining the next remifentanil concentration. The time required for tracheal intubation was measured as the level of intubation stimulation. RESULTS: The average intubation time was 13.9 +/- 9.1 seconds. From the Dixon's method, the EC50 of remifentanil blunting the hemodynamic response to tracheal intubation was 2.94 ng/ml. CONCLUSIONS: This study shows that effect-site concentrations of remifentanil of 2.94 ng/ml is effective in blunting sympathetic responses to tracheal intubation in 50% of patients with normal airway anatomy when combined with a target controlled infusion of propofol (4 microg/ml).

A comparative evaluation of humidifier with heated wire breathing circuit under general anesthesia / 대한마취과학회지

BACKGROUND: Dry and cold anesthetic gas deteriorates patient's respiratory function and body heat balance. We examined whether a humidifier with heated wire circuit might maintain core temperature and humidity of inspired gas in patient undergoing general anesthesia. METHODS: We enrolled forty ASA physical status I, II patients under general anesthesia for this study. We allocated the patients randomly into two groups with (experimental group) or without (control group) Humitube(R) anesthesia circuit, which delivered heated and humidified inspired anesthetic gases. We recorded the temperatures and humidity of the inspired gases throughout the surgery. RESULTS: The temperatures and relative humidity of the inspired gases in experimental group were significantly greater compared to control group (36.2 +/- 0.9degrees C, 89.5 +/- 4.8% vs. 30.4 +/- 1.8degrees C, 37.9 +/- 5.9%, P < 0.05) during anesthesia. The core temperatures in experimental group were significantly greater compared to control group (36.1 +/- 0.3degrees C vs. 35.7 +/- 0.1degrees C, P < 0.05) during anesthesia. CONCLUSIONS: A humidifier with heated wire system for anesthesia breathing circuit is helpful to maintain core temperature and adequate humidity.

A comparison of transcutaneous and end-tidal measurements of CO2 tension in laparoscopic surgery

BACKGROUND: In laparoscopic surgery with pneumoperitoneum, end-tidal CO2 (PeTCO2) monitoring may inaccurately estimate PaCO2 due to ventilation/perfusion mismatch. This study assessed the clinical usefulness and accuracy of transcutaneous CO2 (PtCCO2) monitoring during laparoscopic surgery. METHODS: Thirty-two patients with ASA physical status 1 requiring laparoscopic surgery were recruited. We measured PaCO2, PeTCO2, and PtCCO2 before and 20 min after pneumoperitoneum. To compare differences in PeTCO2/PaCO2 and PtCCO2/PaCO2, we determined bias values (mean difference between values) and precision (standard deviation of bias) with a Bland-Altman plot and compared them with a Student's t-test. RESULTS: Bias and precision values of PeTCO2/PaCO2 and PtCCO2/PaCO2 were 6.6 +/- 2.0 mmHg, 1.2 +/- 2.8 mmHg before pneumoperitoneum and 8.5 +/- 2.8 mmHg, 2.1 +/- 4.5 mmHg 20 min after pneumoperitoneum. PtCCO2/PaCO2 differences were significantly smaller than PeTCO2/PaCO2 differences (P< 0.05). CONCLUSIONS: In laparoscopic surgery, PtCCO2 monitoring is more accurate than PeTCO2 monitoring for assessing PaCO2 levels.

Factors that influence awakening in coronary artery bypass graft using propofol and remifentanil / 대한마취과학회지

BACKGROUND: The development of total intravenous anesthesia in coronary artery bypass graft (CABG) surgery has led to increased interest in the use of combination of propofol and remifentanil. Early extubation in post-cardiac surgery reduces the length of stay in intensive care unit and hospital and costs. The purpose of this study is to evaluate which anesthetic factors affect awakening time after anesthesia. METHODS: We enrolled twenty patients of ASA physical status II or III, scheduled for CABG in this study. All patients received a standardized propofol/remifentanil anesthesia as an effect site target controlled infusion. We recorded times to awakening and tracheal extubation, duration of cardiopulmonary bypass (CPB) period, total time of anesthesia and operation. Also, we recorded dose of propofol, remifentanil, fentanyl and minimum body temperature during CPB. To predict the factors that affect awakening time as a dependent variable, we considered all measured parameters as independent variables, and analyzed multiple linear regressions. RESULTS: The mean time responded to verbal command was 216.5 +/- 124.8 minutes after end of surgery. Among several parameters, minimum body temperature during CPB (P = 0.001) and total time of anesthesia (P = 0.003) were considered as significant factors that influence awakening time after CABG. CONCLUSIONS: Minimum body temperature during CPB and the duration of anesthesia influence awakening time after CABG, significantly.

The Effect of Low Dose Aprotinin in Patients with Adolescent Idiopathic Scoliosis Undergoing Posterior Spinal Fusion

BACKGROUND: Aprotinin is a kallikrein inhibitor at high doses and a plasmin inhibitor at low doses. Low-dose aprotinin has been shown to reduce transfusion requirements in patients undergoing liver resection, open-heart surgery, and spine deformity surgery. The aim of this study was to evaluate the effect of low-dose aprotinin on perioperative blood loss and on transfusion requirements in adolescent idiopathic scoliosis (AIS) patients undergoing posterior spinal fusion. METHODS: We studied forty patients who were set to undergo posterior spinal fusion. Twenty patients were given aprotinin, and twenty control patients were not given aprotinin. Patients were assessed for pre- and post-operative hemoglobin, hematocrit, platelet count, blood urea nitrogen, and creatinine. Perioperative blood loss was measured through suction drains and gauze, and transfusion requirements were recorded. RESULTS: Upon comparing the aprotinin and control groups, we found no differences in intraoperative blood loss (1,456 +/- 622 ml vs 1,625 +/- 738 ml, respectively, [P = 0.17]), total (intraoperative and 24 h postoperative) blood loss (2,544 +/- 977 ml vs 2,594 +/- 783 ml, respectively, [P = 0.42]), or homologous transfusion requirements (1,672 +/- 1,077 ml vs 1,520 +/- 718 ml packed RBCs, respectively, [P = 0.52]). Renal function was maintained in both groups. CONCLUSIONS: Low-dose aprotinin does not decrease blood loss or transfusion requirements in AIS patients undergoing posterior spinal fusion. Renal function was maintained in both the aprotinin and control groups.