Bon Nyeo Koo

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%).

Hepatic resection by the cavitron ultrasonic surgical Aspirator® increases the incidence and severity of venous air embolism

The Cavitron Ultrasonic Surgical Aspirator (CUSA®) is an innovative tool for resecting hepatic parenchyma, which reduces intraoperative blood loss and perioperative morbidity. We designed this study to compare the incidence and severity of venous air embolism (VAE) detected via transesophageal echocardiography (TEE) during hepatic resection by using either the clamp-crushing method or the CUSA® method. Fifty patients scheduled for hepatic resection were randomly assigned to receive hepatic resection by the clamp-crushing method (CC group) or by CUSA® (CUSA® group). After the induction of anesthesia, the TEE probe was inserted into the patient’s esophagus. An independent anesthesiologist graded VAE shown in the 4-chamber view of TEE. All patients in the CUSA® group showed VAE during hepatic resection and 44% of the patients had air embolism filling more than half the right heart diameter. In CC group, 68% of the patients showed VAE, which filled less than half the right heart diameter. There were no significant differences in hemodynamics and end-tidal CO2 partial pressure between the two groups. In conclusion, hepatic resection by CUSA® increases the incidence and severity of VAE.

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.

Effect of Ginseng Saponins on the Recombinant Serotonin Type 3A Receptor Expressed in Xenopus Oocytes: Implication of Possible Application as an Antiemetic

OBJECTIVES Nausea and vomiting are the most frequently reported side-effects by patients who are given general anesthesia perioperatively and patients with cancer who undergo chemotherapy or radiotherapy. Serotonin (5-hydroxytryptamine, 5HT) type 3A receptor (5HT(3A) receptor) is known to mediate nausea and vomiting and its antagonists have been used effectively to prevent and/or reduce the incidence and severity of nausea and vomiting. However, the adverse effects on cardiac function, such as QT interval prolongation, limit their routine use by these patients. This study was designed to elucidate the effect of ginseng saponins on the recombinant 5HT(3A) receptor expressed in the xenopus oocyte. DESIGN After in vitro transcription of the recombinant human 5HT(3A) receptor in the Xenopus laevis oocyte, we examined Panax ginseng saponins (total saponin [TS], panaxadiol saponin [PD] fraction, panaxatriol saponin [PT] fraction, and ginsenoside-Rb1 and -Rg1) for their ability to inhibit current flow through the 5HT(3A) receptor using the voltage-clamp technique. RESULTS All saponin fractions (TS, PD, PT fraction, as well as ginsenoside-Rb1 and -Rg1) inhibited the peak current induced by the agonist 5HT on the 5HT(3A) receptor in a concentration-dependent, reversible, and voltage-independent manner. The PT fraction inhibited 5HT-induced currents in 5HT(3A) receptor more than the PD fraction; meanwhile, there was a similar degree of inhibition between ginsenoside-Rg1 and -Rb1, the main substitutes of PT fraction and PD saponin fractions, respectively. CONCLUSIONS These results indicate that ginseng saponins, especially PT fraction, have substantial inhibitory effects on the recombinant 5HT(3A) receptor, suggesting that some of the specific types of ginsenoside might have an antagonistic action against 5HT(3A) receptor related to nausea and vomiting.

Comparison of Remifentanil and Fentanyl for Postoperative Pain Control after Abdominal Hysterectomy

Purpose In this randomized, double-blind study, we investigated the analgesic efficacy and side effects of continuous constant-dose infusions of remifentanil after total abdominal hysterectomy and compared it to fentanyl. Materials and Methods Fifty-six adult female patients scheduled for elective total abdominal hysterectomy were enrolled in this study. Patients were randomly assigned to two groups according to fentanyl (group F, n = 28) or remifentanil (group R, n = 28) for postoperative analgesia. Patients in group F were given fentanyl intravenously with an infusion rate of fentanyl 0.5 µg/kg/hr; group R was given remifentanil with an infusion rate of remifentanil 0.05 µg/kg/min for 2 days. Pain intensity at rest, occurrence of postoperative nausea and vomiting (PONV), dizziness, pruritus, and respiratory depression were assessed 1 hr after arrival at the post-anesthesia care unit, at 6; 12; 24; and 48 hr postoperation and 6 hr post-infusion of the study drug. Pain was evaluated by using visual analogue scale (VAS; 0 - 10). The time that patients first requested analgesics was recorded as well as additional analgesics and antiemetics. Results There were no significant differences in VAS, time to first postoperative analgesics, and additional analgesics between the 2 groups. The incidences and severities of PONV and opioid related side effects were not different between the groups; however, there were 3 episodes (10.7%) of serious respiratory depression in group R. Conclusion Continuous infusion technique of remifentanil did not reveal any benefits compared to fentanyl. Furthermore, it is not safe for postoperative analgesia in the general ward.

Agmatine promotes the migration of murine brain endothelial cells via multiple signaling pathways

AIMS The combination of adhesion and migration of endothelial cells (ECs) is an integral process for evolution, organization, repair and vessel formation in living organisms. Agmatine, a polycationic amine existing in brain, has been investigated to exert neuroprotective effects. Up to date, there are no studies reporting that agmatine modulates murine brain endothelial (bEnd.3) cells migration. In the present study, we intend to investigate the role of agmatine in bEnd.3 cells migration and the molecular mechanism mediating this action. MAIN METHODS The effect of agmatine on the bEnd.3 cells migration was examined by migration assay, and the mechanism involved for this effect was investigated by western blot analysis and NO contents measurements. KEY FINDINGS Agmatine treatment (50, 100 and 200 μM) significantly accelerated bEnd.3 cells migration in a concentration-dependent manner. Western blotting revealed that agmatine treatment significantly induced vascular endothelial growth factor (VEGF), VEGF receptor 2 (Flk-1/KDR or VEGFR2), phosphatidylinositol 3-kinase (PI3K), Akt/protein kinase B (also known as PKB, PI3K downstream effector protein), endothelial nitric oxide synthase (eNOS) nitric oxide (NO; product by eNOS) and intercellular adhesion molecule 1 (ICAM-1) expressions during bEnd.3 cells migration. The expression of ICAM-1 and migration of bEnd.3 cells, induced by agmatine, were significantly attenuated by treatment of wortmannin, a specific PI3K inhibitor. SIGNIFICANCE Taken together, we provide the first evidence that activation of VEGF/VEGFR2 and the consequential PI3K/Akt/eNOS/NO/ICAM-1 signaling pathways are serial events, through which the treatment of agmatine could lead to bEnd.3 cells migration.

Ramosetron for the prevention of postoperative nausea and vomiting (PONV): a meta-analysis

Background Postoperative nausea and vomiting (PONV) remains a challenge for patients and health professionals despite various newly developed prophylactic interventions. We reviewed the efficacy and safety of ramosetron in randomized controlled trials (RCTs) for the prevention of PONV. Methods We reviewed 18 randomized controlled trials investigating the efficacy and safety of ramosetron in comparison with placebo or any other drugs. Relevant studies were searched in the MEDLINE, SCOPUS, and the Cochrane database libraries. Our end points of concern were prevention of PONV and adverse effects as dichotomous data. Results The prophylactic effect of 0.3 mg ramosetron was observed in early PON (relative risk, RR: 0.4; 95% CI 0.3-0.6), early POV (RR: 0.3; 95% CI 0.1-0.6), late POV (RR: 0.3; 95% CI 0.1-0.6), but not late PON (RR: 0.7; 95% CI 0.5-1.0). Compared with placebo, the efficacy of 0.3 mg ramosetron in adults and 6 µg/kg in children were consistently beneficial in preventing PONV overall (RR: 0.4; 95% CI: 03-0.6). The effects of 0.3 mg ramosetron and 3 mg granisetron were similar. No serious side effects or adverse events resulted from ramosetron and other active drugs, and incidence was similar to those of the placebo group. Conclusions Ramosetron is effective and safe in children and adults without serious adverse effects compared with placebo or other active drugs, as shown in pooled data of RCTs, in terms of the prevention of PONV.

Transient postoperative harlequin syndrome combined with Horner's syndrome in a pediatric patient after neck mass excision

SIR—The term ‘harlequin syndrome’ represents a localized autonomic dysfunction characterized by hemifacial flushing and sweating, dividing the face into two regions (1). This syndrome may be encountered in a number of conditions, such as idiopathic hyperhidrosis, thoracoscopic sympathectomy, high thoracic paravertebral block, internal jugular vein catheterization and asymmetrical high epidural block (2–4). Perioperative harlequin syndrome associated with surgical damage has been rarely reported in children (3). We report a case of harlequin syndrome combined with Horner’s syndrome in a 5-year old boy who underwent left neck mass resection (Figure 1). In this patient, right hemifacial flushing with left Horner’s syndrome developed in PACU. It is thought to be surgery-related interruption of sympathetic outflow that causes such syndromes. The preganglionic oculomotor fibers leave the spinal cord at T1, whereas sudomotor and vasomotor fibers leave at T2 and T3. The fibers then ascend via the sympathetic chain to synapse in the superior cervical ganglion. The postganglionic fibers from the rostral superior cervical ganglion enter the internal carotid nerve supplying the eyes, forehead, and cheeks, whereas the fibers from the caudal part project into the external carotid nerve supplying the cheeks and jaw (Figure 2). Sympathetic nerve injury at these levels results in ipsilateral Horner’s syndrome and facial pallor, whereas active functional sympathetically mediated vasodilation is enhanced on the other side of the face (4). Therefore, the coexistence of Horner’s and harlequin syndrome in our case may be attributable to sympathetic fiber damage caused by difficult resection of the neck mass. The unilateral facial flushing can be exacerbated by crying, heat and emotional embarrassment (5). In our case, intense emotion and convective heating with forced warm air might have accelerated the harlequin syndrome. The unilateral facial flushing subsided gradually over the next 6 h. However, Horner’s syndrome persisted until the next morning. Hae K. Kil Won O. Kim Jang E. Cho Bon N. Koo Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, South Korea (email: hkkil@yumc.yonsei.ac.uk)

Synergistic activation of lipopolysaccharide-stimulated glial cells by propofol.

Despite the extensive use of propofol in general anesthetic procedures, the effects of propofol on glial cell were not completely understood. In lipopolysaccharide (LPS)-stimulated rat primary astrocytes and BV2 microglial cell lines, co-treatment of propofol synergistically induced inflammatory activation as evidenced by the increased production of NO, ROS and expression of iNOS, MMP-9 and several cytokines. Propofol augmented the activation of JNK and p38 MAPKs induced by LPS and the synergistic activation of glial cells by propofol was prevented by pretreatment of JNK and p38 inhibitors. When we treated BV2 cell culture supernatants treated with LPS plus propofol on cultured rat primary neuron, it induced a significant neuronal cell death. The results suggest that the repeated use of propofol in immunologically challenged situation may induce glial activation in brain.