Won Oak Kim

Detection of Subclinical CO2 Embolism by Transesophageal Echocardiography During Laparoscopic Radical Prostatectomy

OBJECTIVES To document incidences of subclinical embolism in laparoscopic radical prostatectomy with continuous monitoring using transesophageal echocardiography (TEE). METHODS A total of 43 patients scheduled for elective robotic-assisted laparoscopic radical prostatectomy under general anesthesia were enrolled in this study. A 4-chamber view of 5.0-MHz multiplane TEE was continuously monitored to detect any intracardiac bubbles as an embolism. An independent TEE specialist reviewed the tapes for interpretation, and emboli were classified as 1 of 5 stages. Cardiorespiratory instability during gas emboli entry was defined as an appearance of cardiac arrhythmias, sudden decrease in mean arterial blood pressure >20 mm Hg, or an episode of pulse oximetric saturation <90%. RESULTS Gas embolisms were observed in 7 of 41 (17.1%) patients during transection of the deep dorsal venous complex. Of them, 1, 3, 1, and 2 showed stage I, II, III, and IV, respectively. However, there were no signs of cardiorespiratory instability associated with emboli. The 95% confidence interval for gas embolism was 0.204%-0.138%. No correlation was observed between episodes of gas embolism and blood gas variables or end-tidal CO(2) partial pressure. CONCLUSIONS Subclinical gas embolisms occur in 17.1% of laparoscopic radical prostatectomies. We should consider that this procedure has a potential for serious gas embolism, especially with the increasing popularity of laparoscopic prostatectomy using robot-assisted techniques.

Prepuncture Ultrasound-Measured Distance: An Accurate Reflection of Epidural Depth in Infants and Small Children

Background and Objectives: Epidural cannulation is technically difficult in children who have small anatomic structures. Ultrasound information regarding the distance of skin-to-ligament flavum may be useful, leading to an increase in success rate without dural puncture. This study was performed to assess whether ultrasound-measured, skin-to-ligament flavum distance would reflect the needle depth during epidural puncture in infants and children. Methods: The study compromised 180 children, aged 2 to 84 months, undergoing urologic surgery. After induction of anesthesia, ultrasound images of the longitudinal median and transverse views were acquired from L4-L5 in lateral decubitus position. Measured distance of skin-to-ligament flavum in each view was compared with the perpendicular skin-to-epidural depth, which was obtained from needle depth and angle by use of a trigonometric ratio equation. Additionally, we evaluated the ultrasound visibility of the ligament flavum and dura mater, number of puncture attempts, and complications. Results: The correlation coefficient between measured distance and perpendicular epidural depth was slightly higher in longitudinal median view (R2 = 0.848) than in transverse view (R2 = 0.788). The visibility of ligament flavum and dura mater was “good” in 91 and 170 of 180 patients, respectively, and “sufficient” in the remaining subjects. The epidural space was located on first puncture attempt in 179 of 180 cases (99.4%). No incidents of dural puncture or bloody tap occurred. Conclusions: Ultrasound, particularly in the longitudinal median view, provides accurate information on the distance of skin-to-ligament flavum in infants and children. With reference to the measured distance, epidural puncture can be performed with minimal risk of dural puncture (upper limit of 95% CI = 1.67%).

A Comparison of High Volume/Low Concentration and Low Volume/High Concentration Ropivacaine in Caudal Analgesia for Pediatric Orchiopexy

BACKGROUND: It is unclear whether the volume or concentration of local anesthetic influences its spread and quality of caudal analgesia when the total drug dose is fixed. METHODS: We performed this study in a prospective, randomized, observer-blind manner. Children aged 1–5 yr received a constant dose of 2.25 mg/kg of ropivacaine prepared as either 1.0 mL/kg of 0.225% (low volume/high concentration [LVHC], n = 37) or 1.5 mL/kg of 0.15% solution (high volume/low concentration [HVLC], n = 36). Both solutions contained radiopaque dye. RESULTS: The median spread levels with ranges in the HVLC group (confirmed by fluoroscopic examination) were significantly higher (T6, T3-11) than in the LVHC group (T11, T8-L2). There were no significant differences in recovery times, postoperative pain scores, or side effects between the two groups. After discharge, fewer children in the HVLC group required rescue oral acetaminophen compared with the LVHC group (50.0% vs 75.7%). First oral acetaminophen time was found to be significantly longer with HVLC patients than LVHC patients (363.0 min vs 554.5 min). CONCLUSIONS: We confirmed (with fluoroscopy) that a caudal block with 1 mL/kg ropivacaine spreads to T11 and to T6 with 1.5 mL/kg. If the total dose is fixed, caudal analgesia with a larger volume of diluted ropivacaine (0.15%) provides better quality and longer duration after discharge than a smaller volume of more concentrated ropivacaine (0.225%) in children undergoing day-case orchiopexy. The spread level of ropivacaine correlated significantly with the first oral acetaminophen time after discharge.

Learning by computer simulation does not lead to better test performance than textbook study in the diagnosis and treatment of dysrhythmias

STUDY OBJECTIVE To compare computer-based learning with traditional learning methods in studying advanced cardiac life support (ACLS). DESIGN Prospective, randomized study. SETTING University hospital. MEASUREMENTS Senior medical students were randomized to perform computer simulation and textbook study. Each group studied ACLS for 150 minutes. Tests were performed 1 week before, immediately after, and 1 week after the study period. Testing consisted of 20 questions. All questions were formulated in such a way that there was a single best answer. Each student also completed a questionnaire designed to assess computer skills, as well as satisfaction with and benefit from the study materials. MAIN RESULTS Test scores improved after both textbook study and computer simulation study in both groups, although the improvement in scores was significantly higher for the textbook group only immediately after the study. There was no significant difference between groups in their computer skill and satisfaction with the study materials. The textbook group reported greater benefit from study materials than did the computer simulation group. CONCLUSIONS Studying ACLS with a hard-copy textbook may be more effective than computer simulation for acquiring simple information during a brief period. However, the difference in effectiveness is likely transient.

Determination of the optimal angle for needle insertion during caudal block in children using ultrasound imaging

Using ultrasound imaging, the optimal angle for needle insertion during caudal epidural injection in children was estimated. After general anaesthesia, ultrasonography was performed at the sacral hiatus in 130 children aged 2–84 months positioned in the lateral position. The median [range] values for the intercornual, caudal space depth and the distance from skin to the posterior sacral bony surface were 17.0 [9.6–24] mm, 3.5 [1–8] mm and 21.0 [10–39] mm, respectively. The optimal angle showed no significant correlation with age, weight, height or body surface area. The median [range] calculated optimal angle for the needle was 21.0 [10–38]°. We conclude that the needle should be inserted at about 20° to the skin to avoid puncture of the bone and potential intra‐osseous injection.

Topical glycopyrrolate for patients with facial hyperhidrosis.

Background  Facial hyperhidrosis may negatively impact the quality of life. Although various conservative modalities have been suggested, the condition is not often treated successfully.

Fentanyl Sparing Effects of Combined Ketorolac and Acetaminophen for Outpatient Inguinal Hernia Repair in Children

PURPOSE In this prospective, randomized, double-blinded study we sought to evaluate the efficacy and safety of combined use of intravenous ketorolac and acetaminophen in small children undergoing outpatient inguinal hernia repair. MATERIALS AND METHODS We studied 55 children 1 to 5 years old who were undergoing elective repair of unilateral inguinal hernia. After induction of general anesthesia children in the experimental group (28 patients) received 1 mg/kg ketorolac and 20 mg/kg acetaminophen intravenously. In the control group (27 patients) the same volume of saline was administered. All patients received 1 microg/kg fentanyl intravenously before incision. We also evaluated the number of patients requiring postoperative rescue fentanyl, total fentanyl consumption, pain scores and side effects. RESULTS Significantly fewer patients receiving ketorolac-acetaminophen received postoperative rescue fentanyl compared to controls (28.6% vs 81.5%). A significantly lower total dose of fentanyl was administered to patients receiving ketorolac-acetaminophen compared to controls (0.54 vs 1.37 microg/kg). Pain scores were significantly higher in the control group immediately postoperatively but eventually decreased. The incidences of sedation use (55.6% vs 25.0%) and vomiting (33.3% vs 10.7%) were significantly higher in controls. CONCLUSIONS Preoperative intravenous coadministration of ketorolac and acetaminophen is a simple, safe and effective method for relieving postoperative pain, and demonstrates highly significant fentanyl sparing effects in small children after outpatient inguinal hernia repair.

Fentanyl-sparing Effect of Acetaminophen as a Mixture of Fentanyl in Intravenous Parent-/Nurse-controlled Analgesia after Pediatric Ureteroneocystostomy

Background:Although acetaminophen has been used widely and is well tolerated in children, its efficacy and safety have not been clarified when combined with an opioid in intravenous parent-/nurse-controlled postoperative analgesia. Methods:Sixty-three children (aged 6–24 months) who had undergone elective ureteroneocystostomies were enrolled in this prospective, randomized, double-blinded study. After the surgery, an analgesic pump was programmed to deliver fentanyl at a basal infusion rate of 0.25 &mgr;g · kg−1 · h−1 and 0.25 &mgr;g/kg bolus after a loading dose of 0.5 &mgr;g/kg. In the fentanyl–acetaminophen group, acetaminophen was coadministered as a solution mixture at a basal infusion rate of 1.5 mg · kg−1 · h−1 and 1.5 mg/kg bolus after a loading dose of 15 mg/kg, whereas saline was administered to the fentanyl group. Results:Postoperative pain scores were similar between the two groups. The total dose (micrograms per kilogram per day, mean ± SD) of fentanyl at postoperative days 1 (8.3 ± 3.7 vs. 18.1 ± 4.6, P = 0.021) and 2 (7.0 ± 2.4 vs. 16.6, P = 0.042) was significantly less in the fentanyl–acetaminophen group compared with that in the fentanyl group. The incidences of vomiting (16.1 vs. 56.3%, P = 0.011) and sedation (9.7 vs. 46.9%, P = 0.019) were significantly lower in the fentanyl–acetaminophen group than those in the fentanyl group. Conclusions:Acetaminophen has significant fentanyl-sparing effects and reduces side effects when combined with fentanyl in intravenous parent-/nurse-controlled analgesia for postoperative pediatric pain management.

Ultrasound evaluation of the sacral area and comparison of sacral interspinous and hiatal approach for caudal block in children.

Background:Although caudal block via the sacral hiatus is a common regional technique in children, it is sometimes difficult to identify the hiatus. A needle approach via the S2–3 interspace can be used as an alternative to the conventional approach. The authors compared the feasibility and clinical characteristics between the S2–3 approach and hiatal approach, in addition to ultrasound study. Methods:Sacral space depth, dural sac end level, and caudal space depth were evaluated using ultrasound with high-frequency linear probe in the lateral decubitus position in 317 anesthetized children (study 1). In another 162 children who underwent ambulatory urological surgeries, success rate, drug spread, and clinical characteristics were compared between the hiatal and S2–3 approaches (study 2). Results:The dural sac end level was S2U (S3M–L5M). The median depth of the sacral space at the S2–3 level was 7.3 mm, whereas the caudal space depth at the hiatus was 2.9 mm. The overall success rate was 96.3% in both groups. The success rates at the first puncture attempt were 96.2% in the S2–3 group and 77.5% in the hiatus group. Drug spread level and clinical characteristics were similar between the two groups. Conclusions:The S2–3 approach can be applied as a useful fallback method to the conventional landmark approach in children, especially in those older than 36 months who present with difficult identification of the sacral hiatus.

Palonosetron has superior prophylactic antiemetic efficacy compared with ondansetron or ramosetron in high-risk patients undergoing laparoscopic surgery: a prospective, randomized, double-blinded study

Background Postoperative nausea and vomiting (PONV) continues to be a major problem, because PONV is associated with delayed recovery and prolonged hospital stay. Although the PONV guidelines recommended the use of 5-hydroxy-tryptamine (5-HT3) receptor antagonists as the first-line prophylactic agents in patients categorized as high-risk, there are few studies comparing the efficacies of ondansetron, ramosetron, and palonosetron. The aim of present study was to compare the prophylactic antiemetic efficacies of three 5HT3 receptor antagonists in high-risk patients after laparoscopic surgery. Methods In this prospective, randomized, double-blinded trial, 109 female nonsmokers scheduled for elective laparoscopic surgery were randomized to receive intravenous 4 mg ondansetron (n = 35), 0.3 mg ramosetron (n = 38), or 75 µg palonosetron (n = 36) before anesthesia. Fentanyl-based intravenous patient-controlled analgesia was administered for 48 h after surgery. Primary antiemetic efficacy variables were the incidence and severity of nausea, the frequency of emetic episodes during the first 48 h after surgery, and the need to use a rescue antiemetic medication. Results The overall incidence of nausea/retching/vomiting was lower in the palonosetron (22.2%/11.1%/5.6%) than in the ondansetron (77.1%/48.6%/28.6%) and ramosetron (60.5%/28.9%/18.4%) groups. The rescue antiemetic therapy was required less frequently in the palonosetron group than the other groups (P < 0.001). Kaplan-Meier analysis showed that the order of prophylactic efficacy in delaying the interval to use of a rescue emetic was palonosetron, ramosetron, and ondansetron. Conclusions Single-dose palonosetron is the prophylactic antiemetics of choice in high-risk patients undergoing laparoscopic surgery.