The State of Anesthetic Services in Korea: A National Survey of the Status of Anesthesia Provider in the 2011-2013 Period

Active involvement of anesthesiologists in perioperative management is important to ensure the patients' safety. This study aimed to investigate the state of anesthetic services in Korea by identifying anesthetic service providers. From the insurance claims data of National Health Insurance for 3 yr, the Korean state of anesthetic services was analyzed. The claims for anesthesia from the medical institutions which hire their own anesthesiologist or with an anesthesiologist invitation fee are assumed to be the anesthesia performed by anesthesiologists. The annual anesthetic data were similar during the study period. In 2013, total counts of 2,129,871 were composed with general anesthesia (55%), regional anesthesia (36%) and procedural sedation with intravenous anesthetics (9%). About 80% of total cases of general anesthesia were performed in general hospitals, while more than 60% of the regional anesthesia and sedation were performed in the clinics and hospitals under 100 beds. Non-anesthesiologists performed 273,006 cases of anesthesia (13% of total) including 36,008 of general anesthesia, 143,134 of regional anesthesia, and 93,864 of sedation, mainly in the clinics and hospitals under 100 beds. All procedural sedations in the institutions without direct employed anesthesiologist were performed by non-anesthesiologists. Significant numbers of anesthesia are performed by non-anesthesiologist in Korea. To promote anesthetic services that prioritize the safety of patients, the standard to qualify anesthetic service is required. Surgeons and patients need to enhance their perception of anesthesia, and the payment system should be revised in a way that advocates anesthesiologist-performed anesthetic services.

A detection of unexpected blood antibody at the time of transfusion was needed, during the operation: A case report / 대한마취과학회지

To avoid the occurrence of fatal complications of blood transfusion, several tests are implemented before transfusion. The tests include ABO typing, Rh typing, cross-matching test and blood antibody screening test, and in usual they are completed before transfusion. However in the case of repetitive operations done via brief distance, reexamination for blood antibody tends to be omitted. After 2 previous operations, 30 years old male patient showed positive blood antibody screening during the third operation. Although antibody screening test performed before the first operation, no unexpected blood antibody was detected. During the third operation, after the decision to start transfusion was made, it took two hours to find appropriate blood. There was no significant deterioration of patient's condition but the loss of time could lead to critical consequences. We present this case to make anesthesiologists and surgeons aware of possibility of unexpected blood antibody detection after transfusion.

Frequency of unexpected antibody and consideration during transfusion / 대한마취과학회지

BACKGROUND: In this retrospective study, we measured the frequency of unexpected antibodies in the blood. Specific considerations for preoperative preparations were kept in mind for the patients undergoing surgery positive for these antibodies. METHODS: After reviewing the results of antibody screening tests lasted for 2 years, the frequency of unexpected antibodies was determined. Surgical patients who were positive for unexpected antibodies were selected and divided into two groups based on their potential need for an intra-operative transfusion (groups with high versus low possibility of transfusion). Blood for the high possibility group was prepared before surgery. For the low possibility group for which preoperative blood preparation was not performed, cases of this group were reviewed whether a blood preparation was delayed or not in case of transfusion. RESULTS: Among a total 22,463 cases, 340 (1.52%) had positive results for antibody screening tests. Among the 243 patients who were positive for unexpected antibodies, Lewis, Rh, Xga, and mixed antibodies were found in 85, 25, five, and eight cases, respectively. Out of 243 patients, 117 patients, specificities of the unexpected antibodies were not determined and 125 (51.4%) had a history of pregnancy and delivery, and 49 (20.2%) had a history of transfusion. In the low probability group, transfusions were administered for nine patients; transfusion was delayed for two patients due to difficulties with obtaining matched blood. CONCLUSIONS: Patients with unexpected blood antibodies may be at increased risk for delayed transfusion. For rapid transfusion, it might be helpful to keep a record about blood antibodies and introduce a notification system such as medical alert cards. Preoperative blood preparation is needed for timely intraoperative transfusion.

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

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.

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.

The effect of two types of humidifying devices on humidity of inspired gas and tidal volume by ventilator monitoring

BACKGROUND: In general anesthesia, a heat and moisture exchanger (HME) is used to prevent hypothermia and to maintain humidity of inspired gas. We hypothesized that after using a HME expiratory tidal volume decreases because a HME traps the expired vapor.The aim of this study was to evaluate the humidity of expired gas and to investigate the accuracy of tidal volume monitoring. METHODS: Forty patients undergoing elective surgery under general anesthesia were randomly allocated into two groups.Group P (n = 20) used Pall Breathing filter (pall BB25, ACE medical, Korea) and Group H (n = 20) used Hygrobac S (Mallinckrodt Dar, Mirandola, Italy) between endotracheal tube and Y-piece.And with same kind of ventilator, we measured expiratory tidal volume, temperature and relative humidity at before and after HEM.And we recorded expiratory tidal volume monitored by ventilator with and without HME. RESULTS: The relative humidity was significantly higher at before using HEM than after using HEM in both group.The temperature in Group H was higher when measured at before HME but not in Group P.The measured expiratory tidal volume at before and after HEM was not significantly different. The tidal volume monitored by ventilator with HEM was significantly smaller than without HEM, by 3.1% in Group P and 5.3% in Group H. CONCLUSIONS: The HMEs improve inspiratory humidity and temperature of anesthetic gas.But monitored expiratory tidal volume was underestimated when using HMEs.

The effect of tranexamic acid used for spine surgery on blood loss and transfused volume

BACKGROUND: In this randomized controlled study, we evaluate the effect of tranexamic acid on perioperative blood loss and transfused volume in patients undergoing spine surgery. METHODS: We enrolled and randomly allocated 40 patients scheduled for spine surgery under general anesthesia to either tranexamic group or control group. Tranexamic acid was given to tranexamic group with loading dose 10 mg/kg for 15 minutes followed by continuous infusion at the rate of 1 mg/kg/h. In control group, equivalent volume of normal saline was given with the same manner and rate, until the end of procedure. We examined the total blood loss and transfused volume perioperatively. Also we evaluated hemoglobin, platelet, prothrombin time, partial thromboplastin time and thromboelastography before and after surgery. RESULTS: The groups did not differ significantly. Intraoperative blood loss was 1,130.0 +/-563.9 (mean +/-SD) ml in control group and 1,061.5 +/-509.7 ml in tranexamic group. Blood loss at postoperative 12 h and 24 h were 392.0 +/-222.0 ml, 466.0 +/-323.2 ml in control group and 158.5 +/-100.6 ml, 470.2 +/-232.7 ml in tranexamic group respectively. Transfused volumes at intraoperative and postoperative period were differing significantly (1,300.0 +/-709.3 ml, 800.0 +/-343.3 ml in control group compared to 1,020.0 +/-476.3 ml, 340.0 +/-325.0 ml in tranexamic group). CONCLUSIONS: Loading dose of 10 mg/kg tranexamic acid and followed infusion at 1 mg/kg/h reduce perioperative blood transfused volume during spinal surgery.

Subdural hemorrhage after scoliosis correction surgery: A case report / 대한마취과학회지

An 11-year-old boy underwent thoracolumbar surgery to correct a deformity caused by congenital kyphoscoliosis from the 6th thoracic vertebra to the 2nd lumbar vertebra. During a screw insertion, some tore and cerebro-spinal fluid (CSF) leaked. After CSF leakage, the amplitude of the motor evoked potential in the left lower extremity was reduced by 90% compared to baseline value, but there was no nerve damage at the surgical site. His post-surgical mental status did not recover completely. Brain computed tomography revealed a subdural hemorrhage in the inter-hemispheric fissure, with both tentorium and right frontotemporooccipital and diffuse brain edema. On the 4th postoperative day, mental status recovered to near alertness, but upper motor strength was grade II, right lower motor strength was grade II and left lower motor strength was grade I. Right hemifacial palsy was also noted. At 2.5 months after surgery, right facial palsy remained, but motor function recovered to near normal levels with conservative care.

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.

The effect of 6% hydroxyethyl starch (670/0.75) on hemostasis during acute normovolemic hemodilution / 대한마취과학회지

BACKGROUND: Hydroxyethyl starch (HES), a widely used plasma volume expander, has been associated with platelet dysfunction and inhibition of coagulation. Six% HES (Molecular weight 670 kd, molar substitution 0.75) is a plasma volume expander in a physiologically balanced medium of electrolytes, lactate and glucose. The aim of this study is to evaluate the effect of 6% HES (670/0.75) on hemostasis during acute normovolemic hemodilution (ANH). METHODS: Eighteen healthy adult male patients scheduled for spine surgery were enrolled in this study. Before general anesthesia, patients underwent ANH with 20 ml/kg of 6% HES (670/0.75). Hemoglobin, platelet count, plasma fibrinogen concentration, factor VII activity, prothrombin time (PT), activated partial thromboplastin time (aPTT) and thromboelastography (TEG) were measured before and 120 minutes after the completion of ANH. RESULTS: Hb, Hct, platelet, plasma fibrinogen concentration and factor VII activity decreased significantly (P < 0.05) after ANH. Compared with pre-ANH values, only maximal amplitude decreased significantly (P = 0.001) among post-ANH thromboelastographic parameters. CONCLUSIONS: Except maximal amplitude, significant difference were not observed in CI (Coagulation Index) which represents general coagulation state and other thromboelastographic parameters between pre and post ANH. ANH with 20 ml/kg of 6% HES (670/0.75) didn't cause impairment of TEG parameters.

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.

A Comparison of Transcutaneous and End-tidal Measurements of CO2 in One Lung Ventilation / 대한마취과학회지

BACKGROUND: In thoracic anesthesia with one lung ventilation (OLV), end-tidal CO2 (PeTCO2) monitoring may not be accurate to estimate PaCO2 mainly due to ventilation/perfusion mismatching.This study aimed to asses the clinical usefulness and accuracy of a transcutaneous CO2 (PtCCO2) monitoring in thoracic anesthesia, compared with PeTCO2. METHODS: 18 patients of ASA physical status 1 or 2, required a long period of OLV were researched.The lungs were mechanically ventilated in the lateral decubitus position.We measured PaCO2, PeTCO2, PtCCO2 during two lung ventilation (TLV) and 15 min, 30 min, 60 min after OLV.For comparing the differences of PtCCO2/PaCO2 and PtCCO2/PaCO2, we figured out bias (mean difference between values) and precision (standard deviation of bias) by using Bland-Altman plot.We compared the differences of each value, PeTCO2/PaCO2, PtCCO2/PaCO2, using the student's t-test. RESULTS: The bias +/- precision of PeTCO2/PaCO2 and PtCCO2/PaCO2 was each 7.82 mmHg +/- 3.98 mmHg, 1.95 mmHg +/- 2.66 mmHg during TLV and that of mean value of PeTCO2/PaCO2 and PtCCO2/PaCO2 was each 6.93 mmHg +/- 2.6 mmHg, 2.35 mmHg +/- 1.66 mmHg during OLV.PtCCO2/PaCO2 differences were significantly less than PeTCO2/PaCO2 differences (P < 0.05). CONCLUSIONS: During one lung ventilation, PtCCO2 monitoring is more useful and accurate than PeTCO2 monitoring for assessing PaCO2 levels.

Remifentanil Effect-site Concentration Blunting Cardiovascular Responses to Tracheal Intubation for Different Sex during Propofol Infusion / 대한마취과학회지

BACKGROUND: Tracheal intubation induces clinically adverse hemodynamic changes. Various pharmacological strategies for controlling these reponses have been suggested with opioids being widely used. The purpose of this study was to determine the effect site concentration of remifentanil in blunting the cardiovascular responses to tracheal intubation according to gender. METHODS: Eighty ASA physical status I or II patients, aged 20-40 years undergoing elective surgery, were classified into a male group (n = 40) and a female group (n = 40). Anesthesia was induced using a propofol target controlled infusion (TCI: Marsh model). A propofol target effect-site concentration of 4microgram/ml was chosen. Rocuronium 0.6 mg/kg was administered after the patients lost consciousness. Remifentanil TCI (Minto model) was started 1 min after the propofol injection. Initially, an effect-site concentration of 3 ng/ml was chosen. The next concentration was chosen using the up-and-down method reported by Dixon. The non-invasive blood pressure and heart rate were recorded before induction (baseline), after the remifentanil injection, immediately after intubation as well as 1 and, 3 minutes after intubation. RESULTS: Probit analysis revealed a remifentanil effect-site EC50 and EC95 in the male group to be 1.94 ng/ml (95% CI, 1.60-2.27 ng/ml ), 3.07 ng/ml (95% CI, 2.65-4.06 ng/ml), respectively. The EC50 and EC95 in the female group were 1.69 ng/ml (95% CI, 1.35-2.01 ng/ml), 2.81 ng/ml (95% CI, 2.39-3.81 ng/ml), respectively. There were no significant differences between the two groups. CONCLUSIONS: The effect-site concentration of remifentanil blunting the cardiovascular responses to tracheal intubation during propofol TCI anesthesia was between 2 and 3 ng/ml. There were no gender differences.

Adequate Dose of Remifentanil for Endotracheal Intubation with Propofol without Muscle Relaxants / 대한마취과학회지

ation of remifentanil and the possibility of endotracheal intubation was as following: Probit (P) = - 1.38 (S.E.: 0.58) + 0.087 (S.E.: 0.23) x DRemi. The ED50 of remifentanil for endotracheal intubation without muscle relaxants was 2.12 (95% confidence interval: 1.42-2.62)microgram/kg and the ED95 was 4.01 (95% confidence interval: 3.31-5.92)microgram/kg. CONCLUSIONS: We concluded that adequate dose of remifentanil which make possible to endotracheal intubation without muscle relaxants after induction of general anesthesia with 1.5 mg/kg of propofol is 4.01microgram/kg in 95% of female patients and 2.12microgram/kg in 50% of female patients.

The Effect of Cigarette Smoking on Propofol EC50 of Airway Obstruction during Target Controlled Infusion of Propofol / 대한마취과학회지

BACKGROUND: Airway obstruction is a main cause of respiratory complications during sedation. The aim of this study was to identify the effect of smoking on the target plasma concentration of propofol (EC50) of airway obstruction during target controlled infusion (TCI) of propofol. METHODS: Thirty healthy male adults scheduled for lower extremity surgery under regional anesthesia were randomly allocated to one of five target plasma concentrations (CP) of propofol: 1.0, 2.0, 3.0, 4.0, 5.0microgram/ml (n = 6 for each concentration). After performing regional anesthesia, oxygen was supplied and ETCO2 was measured. All patients received propofol TCI with the assigned CP. The occurrence of airway obstruction was observed until 5 minutes after effect site concentration (CE) reached CP. When hypoxemia, apnea or total airway obstruction was observed, ventilation was assisted with 100% oxygen. The CP, smoking history, snoring history, age, body mass index, Mallampati's classification and thyromental distance were regarded as independent variables. The relationship of airway obstruction and the variables was analyzed with logistic regression with Wald-forward method. By the equation of the probability of airway obstruction 'P = 1/(1 + e-z)', we estimated the propofol EC50 of airway obstruction in smokers and nonsmokers. RESULTS: The result of logistic regression was as following: z (airway obstruction) = -5.557 + 2.128 x CP [microgram/ml] + 3.625 x smoking (CP: P = 0.007, smoking: P = 0.047). The propofol EC50 of airway obstruction of non-smokers and smokers was 2.6 (1.5-9.4)microgram/ml and 0.9 (-9.3)microgram/ml, respectively. CONCLUSIONS: The propofol EC50 of airway obstruction of smokers was lower than that of nonsmokers.

The Effect of Ondansetron and Metoclopramide on the Prevention of Postoperative Nausea and Vomiting After Using Epidural Morphine-Butorphanol Mixture / 대한마취과학회지

BACKGROUND: Neuroaxial morphine may produce nausea and vomiting due to cephalad migration. Though it improves post- operative pain, it may have serious complication delaying recovery. The aim of this study was to investigate the efficacy of prophylactic antiemetics such as conventional metoclopramide or more expensive ondansetron. METHODS: Eighty-seven patients who underwent orthopedic knee arthroscopic surgery under epidural anesthesia were randomly assigned to three groups, which are (a) normal saline intravenous injection control group (Group C), (b) metoclopramide intravenous injection and intranasal spray study group (Group M), (c) ondansetron inravenous injection group (Group O). Before the end of surgery, all patients were given 3 mg of morphine and 2 mg of butorphanol mixture via epidural catheter for postoperative pain control. The anesthesia were all standardized. Post-operative nausea and vomiting were observed and used as outcome variables and postoperative pain, itching, somnolence, dizziness, urinary retention were also observed. RESULTS: The incidence of postoperative nausea was significantly lower in Group M (P = 0.0296) and Group O (P = 0.005) compared with Group C. The incidence of postoperative vomiting was significantly lower in Group O (P = 0.01) compared with Group C. But statistically no difference was noted in vomiting between Group C and Group M (P = 0.0579). CONCLUSIONS: The results suggest that ondansetron and metoclopramide are effective in reducing the incidence of post-operative nausea. But ondansetron is more effective in reducing the incidence of post-operative morphine induced vomiting.

The Influences of 6% HES (130/0.4) Solution on Hemostasis / 대한마취과학회지

BACKGROUND: Hydroxyethyl starches (HES) solutions are the most commonly used colloids for treating hypovolemia and expanding plasma, but they compromise platelet function and reduce the level of coagulation factors. As opposed to other HES solutions, 6% HES (130/0.4) solution may influence hemostasis minimally due to its low mean molecular weight and degree of substitution. This study was designed to establish the safety of HES (130/0.4) infusion in the presence of massive blood loss. METHODS: Twelve healthy adult patients scheduled for spine surgery were enrolled in this study. Before the induction of general anesthesia, all patients underwent acute normovolemic hemodilution (ANH), which was independent of surgical stress and other confounding factors. While approximately 30% of the estimated blood volume was procured, the blood deficit was replaced with the same volume of 6% HES (130/0.4) solution. Hematocrit, platelet count, factor VIII activity and plasma fibrinogen concentration were determined and thrombelastography was performed to evaluate the hemodilution effect and hemostatic impairment before and after ANH. Statistical testing was conducted to analyze the effect of HES on hemostasis. RESULTS: Hematocrit, platelet count, factor VIII activity and plasma fibrinogen concentrations decreased significantly (P < 0.05 respectively) after the ANH. On comparing pre-ANH and post-ANH thrombelastographic findings, the R time was shortened (P = 0.045), the alpha angle increased (P = 0.01) and MA decreased (P = 0.003) significantly. CONCLUSIONS: Summarizing, little effect was observed on the hemostatic system when 20 ml/kg of 6% HES (130/0.4) solution was infused. HES (130/0.4) solution as used to maintain normovolemia during ANH may be free from bleeding risk.

Comparison of Bupivacaine and Normal Saline for Epidural Top-up on Sensory Blockade Level during Combined Spinal Epidural Anesthesia / 대한마취과학회지

BACKGROUND: An increase in the maximum level of sensory blockade by epidural 'top-up' in combined spinal epidural anesthesia may be explained by two mechanisms; a volume effect, compressing the dural sac, and a local anesthetic effect. This study was undertaken to investigate the relative importance of these factors. METHODS: Eighty patients about to undergo lower limb surgery under combined spinal epidural anesthesia were randomly assigned to four groups. Using the needle-through-needle technique, all patients received a subarachnoid injection of 8 mg of heavy bupivacaine through an epidural catheter. At 30 minutes after subarachnoid injection, an epidural top-up was given according to a randomization code. Experimental groups received 10 ml of saline, 10 ml of bupivacaine 0.25%, or 10 ml of bupivacaine 0.5%. The control group received no epidural top-up. The level of sensory blockade was checked by using the pinprick test at 5, 10, 15, 20, 25 and 30 minutes after subarachnoid injection, and at 5, 10, 15, 20, 25 and 30 minutes after epidural top-up. Blood pressure, heart rate and the incidence of side effects such as hypotension, bradycardia, nausea, and high block were analyzed. RESULTS: There was no significant difference in maximum level of sensory block among the 10 ml saline, 10 ml bupivacaine 0.25% or 10 ml bupivacaine 0.5% treated groups during epidural phase. Although blood pressure and heart rate were decreased, there were no differences among experimental groups during epidural phase. The most common side effect during combined spinal epidural anesthesia was hypotension. The incidence of bradycardia and high sensory block (above T4 dermatome level) was similar among the groups. CONCLUSIONS: After the maximum level of sensory blockade due to subarachnoid injection has been established, an epidural top-up with 10 ml of saline or 10 ml of either 0.25% or 0.5% bupivacaine did not significantly increase the level of subarachnoid block in patients with lower extremity surgery. The author concludes the there were no differences among groups with regard to the volume effect and local anesthetic effect in terms of the sensory blockade level during the epidural phase. However, blood pressure and heart rate in the epidural top-up groups reduced with operation time.

Effect of Clonidine Supplementation on Jugular Bulb Oxygen Saturation and Carbon Dioxide Reactivity during Desflurane Anesthesia / 대한마취과학회지

BACKGROUND: The alpha2-agonist clonidine is an adjunct in general anesthesia. Clonidine constricts cerebral arteries and decreases cerebral blood flow (CBF), but does not alter cerebral metabolic rate (CMR). Thus cerebral ischemia is possible due to CBF/CMR imbalance. This study was designed to prove the effects of clonidine bolus up on CBF and CO2 reactivity in desflurane anesthesia. METHODS: Thirty patients were divided into a clonidine group (n = 15) and a control group (n = 15). Anesthesia was induced with thiopental and pancuronium, and maintained with 50% N2O/O2/ Desflurane. The jugular bulb was cannulated to measure jugular bulb oxygen saturation (SjO2). MAP and SjO2 were measured after induction, after clonidine (2 microgram/kg) or normal saline administration and during hyperventilation. RESULTS: After clonidine administration, MAP decreased from 95.7+/-9.8 mmHg to 81.1+/-6.3 mmHg and was 79.9+/-5.0 mmHg during hyperventilation. In the control group, the corresponding MAP values 95.7+/-9.8 mmHg, 81.1+/-6.3 mmHg and 79.9+/-5.0 mmHg. After clonidine administration, SjO2 was decreased from 84.7+/-3.7% to 81.1+/-5.2%, and was 71.5+/-8.4% during hyperventilation (P = 0.003, P = 0.000) and in control group, there were 95.7+/-9.8%, 81.1+/-6.3% and 79.9+/-5.0%, respectively. CO2 reactivity was expressed as a change of SjO2 per unit change of PaCO2, 1.15+/-1.19%/mmHg versus 1.43+/-0.98%/mmHg (P = 0.49). CONCLUSIONS: During desflurane anesthesia, clonidine-induced constriction of the cerebral arteries was demonstrated but CO2 reactivity was well preserved.

The Changes of Coagulation State among ABO Blood Types during Acute Normovolemic Hemodilution / 대한마취과학회지

BACKGROUND: Improvement of coagulation function by acute normovolemic hemodilution (ANH) is well evidenced in modern medical practice. It has been reported that there are fixed differences in the plasma concentrations of von Willebrand factor and factor VIII according to ABO blood types. Therefore, the changes of coagulation state among ABO blood types during ANH are expected but have not yet been studied. This study was designed to establish the changes of coagulation state among ABO blood types during ANH by intraoperative thrombelastography (TEG). METHODS: Fifty one healthy adult patients scheduled for spine surgery were enrolled in this study. All patients were grouped by ABO blood types and underwent ANH after the induction of general anesthesia. While autologous blood (25% of EBV) was procured, warmed 0.9% saline, 3 times the blood volume deficit, was infused to maintain normovolemia. Platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), factor VIII activity and TEG were performed to evaluate coagulation state before and after ANH. Statistical analysis was conducted to determine the dilutional effects and intergroup differences. RESULTS: Improvement of coagulation function after ANH was visible only by TEG, and not by PT, APTT or factor VIII activity. Fourteen of fifteen patients with type O blood showed decreased factor VIII activity to under the normal limit after ANH. In patients with blood type O, changes of APTT (P = 0.093, P = 0.086) and factor VIII activity (P = 0.001, P = 0.004) during ANH were remarkable in comparison with blood type B and AB. CONCLUSIONS: ANH enhances coagulation function evaluated by means of TEG. No difference was observed in terms of the changes of coagulation state among ABO blood types during ANH. However, ANH should be instituted cautiously in patients with type O blood because there is a possibility of impairing factor VIII activity.