Jun Heum Yon

Effects of genetic polymorphisms of OPRM1, ABCB1, CYP3A4/5 on postoperative fentanyl consumption in Korean gynecologic patients.

OBJECTIVE Fentanyl, a μ-opioid receptor agonist, is a substrate of P-glycoprotein. Its metabolism is catalyzed by CYP3A4 and CYP3A5. The aim of this study was to investigate the association between postoperative fentanyl consumption and genetic polymorphisms of μ-opioid receptor (OPRM1), ABCB1 (gene encoding P-glycoprotein), CYP3A4 and CYP3A5 in Korean patients. METHODS 196 female patients scheduled to undergo total abdominal hysterectomy or laparoscopic assisted vaginal hysterectomy under general anesthesia were enrolled in this study. Intravenous patient-controlled analgesia with fentanyl was provided postoperatively. Cumulative fentanyl consumption was measured during the first 48 hours postoperatively. The severity of pain at rest was assessed with the visual analogue scale. OPRM1 118A>G, ABCB1 2677G>A/T, ABCB1 3435C>T, CYP3A4*18 and CYP3A5*3 variant alleles were genotyped. The effects of genetic and non-genetic factors on fentanyl requirements were evaluated with multiple linear regression analysis. RESULTS The 24-hour cumulative fentanyl doses were significantly associated with pain core, weight and type of surgery (p < 0.05). The 48-hour cumulative fentanyl doses were significantly associated with pain score, type of surgery and history of PONV or motion sickness (p < 0.05). Genetic polymorphisms were not associated with fentanyl requirements. CONCLUSION In Korean gynecologic patients, no association was found between genetic factors and postoperative fentanyl consumption.

The effect of remifentanil versus N2O on postoperative pain and emergence agitation after pediatric tonsillectomy/adenoidectomy

Background Remifentanil can be an alternative to N2O in general anesthesia. Intraoperative remifentanil may lead to acute opioid tolerance. This study aims to assess the effect of remifentanil substituted for 70% N2O on postoperative pain in children undergoing tonsillectomy/adenoidectomy. In addition, we evaluated the effect of remifentanil infusion on incidence of emergence agitation in these patients. Methods Eighty children, aged 2-12 years, undergoing tonsillectomy/adenoidectomy were randomly allocated to the N2O group (Group N; n = 40, sevoflurane and 70% N2O) or remifentanil group (Group R; n = 40, sevoflurane with remifentanil infusion at the rate of 0.17 µg/kg/min). In the recovery room, severity of pain and agitation were assessed by an investigator blinded to the assigned group. Time to eye opening and incidence of severe pain and agitation were compared between groups. Logistic regression was used to identify factors related to occurrence of severe pain and agitation. Results Number of patients with severe postoperative pain was 6 and 16 in groups N and R, respectively (P = 0.012). Incidence of emergence agitation was not significantly different between groups. Remifentanil infusion was a significant factor related to the occurrence of severe postoperative pain (P = 0.015), and age was inversely related to occurrence of emergence agitation (P = 0.001). Conclusions In children undergoing tonsillectomy/adenoidectomy, intraoperative remifentanil infusion may increase incidence of severe postoperative pain compared to N2O, but it may not affect incidence of emergence agitation.

Antihyperalgesic effects of ginseng total saponins in a rat model of incisional pain

BACKGROUND The aim of this study was to assess whether intraperitoneal administration of ginseng total saponins (GTS) has antihyperalgesic effects in a rat model of incisional pain. The proinflammatory responses and reversal of the antihyperalgesic effect of GTS by N-methyl-d-aspartate (NMDA) or naloxone were also evaluated. MATERIALS AND METHODS Rats were injected intraperitoneally with 0.9% saline vehicle or various doses of GTS before or after a plantar incision. Paw withdrawal in response to application of the von Frey filament with the lowest bending force marked the mechanical withdrawal threshold (MWT). Blood samples were collected for the assessment of serum interleukin (IL)-1β and IL-6 levels. The IL levels were measured using an enzyme-linked immunosorbent assay kit. Rats were injected intraperitoneally with NMDA or naloxone before the GTS injection to assess the reversal of the antihyperalgesic effect of GTS. RESULTS The MWT measured 2 h after the plantar incision increased significantly after the postincision administration of 50, 100, or 200 mg/kg of GTS compared with the MWT at 2 h after plantar incision. The MWT also increased significantly after the preincision injection of 100 or 200 mg/kg of GTS compared with the MWT of the vehicle control. Administration of GTS suppressed the postincision rise in serum IL-1β levels and NMDA inhibited the increase in the MWT compared with GTS alone. CONCLUSIONS Intraperitoneal administration of GTS before or after surgery induces antihyperalgesic effects in a rat model of incisional pain. The effects on mechanical hyperalgesia may be associated with anti-inflammatory cytokines and NMDA signaling.

The comparative study to evaluate the effect of palonosetron monotherapy versus palonosetron with dexamethasone combination therapy for prevention of postoperative nausea and vomiting

Background 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists are effective and safe on postoperative nausea and vomiting (PONV). Palonosetron, the newest 5-HT3 antagonist, has potent antiemetic property. We hypothesized that a combination of palonosetron and dexamethasone could more decrease PONV than palonosetron alone. Methods Among the patients scheduled to undergo laparoscopic gynecologic surgery, mastoidectomy with tympanoplasty or thyroidectomy under general anesthesia, eighty four female patients with at least two PONV risk factors were enrolled in this study. They were received randomly 0.075 mg palonosetron and 4 mg dexamethasone (group C) or 0.075 mg palonosetron alone (group P). The severity of PONV using Rhodes index and the percentage of complete response during postoperative 24 hours were compared between groups. Results The frequency of mild/moderate/great/severe PONV based on Rhodes index were 9.8%/0%/0%/0% and 9.3%/2.3%/2.3%/0% in group P and group C, respectively. Complete response for PONV was observed in 90.2% and 86% of patients in group P and group C, respectively. The overall incidence of PONV in group P and C was 9.8% and 14%, respectively. There was no significant difference between the two groups. Conclusions There were no differences between palonosetron monotherapy and combination therapy of palonosetron and dexamethasone in patients with high emetogenic risk.

Prediction of Plasma Hemoglobin Concentration by Near-Infrared Spectroscopy

The estimation of plasma hemoglobin concentration (Hb) is among one of the daily activities in the practice of clinical anesthesiology. The near-infrared spectroscopy of the brain (rSO2) represents a balance between cerebral oxygen delivery and consumption. This study was designed to assess the value of rSO2 in the prediction of the Hb level while other variables were mathematically controlled. Thirty healthy adult patients undergoing spine surgery, expected to have a moderate degree of intraoperative bleeding, were enrolled in this study. General anesthesia was given and ventilation was mechanically controlled. Measurement of Hb and PaCO2 were performed at random periods of time. We obtained a total of 97 data combinations for the 30 study patients. The Hb was regressed by independent variables including rSO2 and PaCO2. A multilinear regression analysis was performed and the final regression equation was expressed only with statistically significant variables. The measured Hb was tightly regressed with three variables. The final regression equation was Hb=+8.580+0.238 rSO2-0.338 PaCO2-0.004 anesthetic exposure duration (Tmin) (p=0.000, r2=0.809). Near-infrared spectroscopy was shown to be a valuable predictor of plasma Hb in the clinical anesthesiology setting.

Effect of ramosetron on shivering during spinal anesthesia

Background Shivering associated with spinal anesthesia is uncomfortable and may interfere with monitoring. The aim of this study is to evaluate the effect of ramosetron, a serotonin-3 receptor antagonist, on the prevention of shivering during spinal anesthesia. Methods We enrolled 52 patients who were ASA I or II and who had undergone knee arthroscopy under spinal anesthesia. Warmed (37°) lactated Ringers solution was infused over 15 minutes before spinal anesthesia. Patients were randomly allocated to a control group (group S, N = 26) or study group (group R, N = 26). Spinal anesthesia was performed with a 25-G Quincke-type spinal needle between the lumbar 3-4 interspace with 2.2 ml 0.5% hyperbaric bupivacaine. For patients allocated in groups S and R, 2 ml 0.9% saline and 0.3 mg ramosetron, respectively, was intravenously injected immediately before intrathecal injection at identical times. Shivering and spinal block levels were assessed immediately after the completion of subarachnoid injection, as well as 5, 10, 15, 20, 25, 30, 60, and 120 minutes after spinal anesthesia. Systolic and diastolic blood pressures, heart rate, and peripheral oxygen saturation were also recorded. Core temperatures were measured by tympanic thermometer and recorded before and during spinal anesthesia at 30-minute intervals. Results Shivering was observed in 2 patients in group R and 9 patients in group S (P = 0.038, odds ratio = 6.14, 95% C.I. = 1.08-65.5). The difference in core temperature between the groups was not significant. Conclusions Compared to control, ramosetron is an effective way to prevent shivering during spinal anesthesia.

General anesthesia versus monitored anesthetic care with dexmedetomidine for closed reduction of nasal bone fracture

Background Reduction of nasal bone fracture can be performed under general or local anesthesia. The aim of this study was to compare general anesthesia (GA) and monitored anesthetic care (MAC) with dexmedetomidine based on intraoperative vital signs, comfort of patients, surgeons and nurses and the adverse effects after closed reduction of nasal bone fractures. Methods Sixty patients with American Society of Anesthesiologists physical status I or II were divided into a GA group (n = 30) or MAC group (n = 30). Standard monitorings were applied. In the GA group, general anesthesia was carried out with propofol-sevoflurane-N2O. In the MAC group, dexmedetomidine and local anesthetics were administered for sedation and analgesia. Intraoperative vital signs, postoperative pain scores by visual analog scale and postoperative nausea and vomiting (PONV) were compared between the groups. Results Intraoperatively, systolic blood pressures were significantly higher, and heart rates were lower in the MAC group compared to the GA group. There were no differences between the groups in the patient, nurse and surgeons satisfaction, postoperative pain scores and incidence of PONV. Conclusions MAC with dexmedetomidine resulted in comparable satisfaction in the patients, nurses and surgeons compared to general anesthesia. The incidence of postoperative adverse effects and severity of postoperative pain were also similar between the two groups. Therefore, both anesthetic techniques can be used during the reduction of nasal bone fractures based on a patient%s preference and medical condition.

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

BACKGROUND Dry and cold anesthetic gas deteriorates patients 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.

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

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 µg/ml propofol. The effect-site target-concentration of remifentanil of 5.0 ng/ml was chosen for the first patient. We used the Dixons 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 Dixons 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 µg/ml).

Risk factors associated with outcomes of hip fracture surgery in elderly patients.

Background Hip fracture surgery on elderly patients is associated with a high incidence of morbidity and mortality. The aim of this study is to identify the risk factors related to the postoperative mortality and complications following hip fracture surgery on elderly patients. Methods In this retrospective study, the medical records of elderly patients (aged 65 years or older) who underwent hip fracture surgery from January 2011 to June 2014 were reviewed. A total of 464 patients were involved. Demographic data of the patients, American Society of Anesthesiologists physical status, preoperative comorbidities, type and duration of anesthesia and type of surgery were collected. Factors related to postoperative mortality and complications; as well as to intensive care unit admission were analyzed using logistic regression. Results The incidence of postoperative mortality, cardiovascular complications, respiratory complications and intensive care unit (ICU) admission were 1.7, 4.7, 19.6 and 7.1%, respectively. Postoperative mortality was associated with preoperative respiratory comorbidities, postoperative cardiovascular complications (P < 0.05). Postoperative cardiovascular complications were related to frequent intraoperative hypotension (P <0.05). Postoperative respiratory complications were related to age, preoperative renal failure, neurological comorbidities, and bedridden state (P < 0.05). ICU admission was associated with the time from injury to operation, preoperative neurological comorbidities and frequent intraoperative hypotension (P < 0.05). Conclusions Adequate treatment of respiratory comorbidities and prevention of cardiovascular complications might be the critical factors in reducing postoperative mortality in elderly patients undergoing hip fracture surgery.