Effect on thermoregulatory responses in patients undergoing a tympanoplasty in accordance to the anesthetic techniques during PEEP: a comparison between inhalation anesthesia with desflurane and TIVA / 대한마취과학회지

BACKGROUND: It has been known that positive end-expiratory pressure (PEEP) increases the vasoconstriction threshold by baroreceptor unloading. We compared the effect on the thermoregulatory responses according to anesthetic techniques between an inhalation anesthesia with desflurane and a total intravenous anesthesia (TIVA) with propofol and reminfentanil when PEEP was applied in patients undergoing tympanoplasty. METHODS: Forty-six patients with a scheduled tympanoplasty were enrolled and the patients were divided in two study groups. Desflurane was used as an inhalation anesthetic in group 1 (n = 22), while TIVA with propofol and remifentanil was used in group 2 (n = 24). PEEP was applied by 5 cmH2O in both groups and an ambient temperature was maintained at 22-24degrees C during surgery. The core temperature and the difference of skin temperature between forearm and fingertip were monitored for about 180 minutes before and after the induction of general anesthesia. RESULTS: The final core temperature was significantly higher in group 2 (35.4 +/- 0.7degrees C) than in group 1 (34.9 +/- 0.5degrees C). Peripheral thermoregulatory vasoconstriction was found in 5 subjects (23%) in group 1 and in 21 subjects (88%) in group 2. The time taken for reaching the thermoregulatory vasoconstriction threshold was 151.4 +/- 19.7 minutes in group 1 and 88.9 +/- 14.4 minutes in group 2. CONCLUSIONS: When PEEP will be applied, anesthesia with TIVA may have more advantages in core temperature preservation than an inhalation anesthesia with desflurane.

Effects of lidocaine, ketamine, and remifentanil on withdrawal response of rocuronium / 대한마취과학회지

BACKGROUND: Rocuronium has been well known to produce withdrawal response in 50-80% patients when administered intravenously. Several drugs are administered prior injection of rocuronium to prevent the withdrawal response. We compared the preventive effect of lidocaine, ketamine, and remifentanil on the withdrawal response of rocuronium. METHODS: A total of 120 patients undergoing various elective surgeries were enrolled. Patients were allocated into 4 groups according to the pretreatment drugs (Group N, normal saline; Groups L, lidocaine 40 mg; Group K, ketamine 0.5 mg/kg; Group R, remifentanil 1 microg/kg). Patients received drugs prepared by dilution to 3 ml volume before injection of rocuronium. Withdrawal responses after injection of rocuronium were graded on a 4-point scale. Hemodynamic changes were observed before and after administration of pretreatment drugs and after endotracheal intubation. RESULTS: Incidence of withdrawal response was significantly lower in group L (20%), group K (30%), and group R (0%), than group N (87%). Severe withdrawal response was observed in 5 of the 30 patients (17%) in group L, and in 9 of the 30 patients (30%) in group K. There was no severe withdrawal response in group R. Mean blood pressure and heart rate were significantly decreased in group R compared to other groups. CONCLUSIONS: It seems that remifentanil (1 microg/kg intravenously) was the strongest and most effective in prevention of withdrawal response after rocuronium injection among the 3 drugs.

Effects of a preemptive alveolar recruitment strategy on arterial oxygenation during one-lung ventilation with different tidal volumes in patients with normal pulmonary function test / 대한마취과학회지

BACKGROUND: Hypoxemia during one-lung ventilation (OLV) remains a major concern. The present study compared the effect of alveolar recruitment strategy (ARS) on arterial oxygenation during OLV at varying tidal volumes (Vt) with or without positive end-expiratory pressure (PEEP). METHODS: In total, 120 patients undergoing wedge resection by video assisted thoracostomy were randomized into four groups comprising 30 patients each: those administered a 10 ml/kg tidal volume with or without preemptive ARS (Group H and Group H-ARS, respectively) and those administered a 6 ml/kg tidal volume and a 8 cmH2O PEEP with or without preemptive ARS (Group L and Group L-ARS, respectively). ARS was performed using pressure-controlled ventilation with a 40 cmH2O plateau airway pressure and a 15 cmH2O PEEP for at least 10 breaths until OLV began. RESULTS: Preemptive ARS significantly improved the PaO2/FiO2 ratio compared to the groups that did not receive ARS (P < 0.05). The H-ARS group showed a highest PaO2/FiO2 ratio during OLV, the L-ARS and H groups showed similarly improved arterial oxygenation, which was significantly higher than in group L (P < 0.05). The plateau airway pressure in group H-ARS was significantly higher than in group L-ARS (P < 0.05). CONCLUSIONS: Preemptive ARS can improve arterial oxygenation during OLV. Furthermore, a 6 ml/kg tidal volume combined with 8 cmH2O PEEP after preemptive ARS may reduce the risk of pulmonary injury caused by high tidal volume during one-lung ventilation in patients with normal pulmonary function.

The effects of intrathecal fentanyl for spinal anesthesia in lower extremity surgery / 대한마취과학회지

BACKGROUND: Intrathecal opioids in combination with bupivacaine has been shown to provide adequate sensory blockade and early recovery from spinal anesthesia. This study was investigated the added effects of intrathecal fentanyl 10 microgram to bupivacaine for spinal anesthesia. METHODS: Sixty patients undergoing lower extremity surgery were into three groups. Group I received bupivacaine 10 mg (0.5%), gruop II received bupivacaine 5 mg with normal saline 1 ml, and group III received bupivacaine 5 mg with fentanyl 10 microg and normal saline 0.8 ml. RESULTS: There was no significant difference between group I and group III in the peak level and duration of sensory block. But the intensity of motor blockade was decreased in group III compared with group I and side effects of spinal anesthesia with local anesthetics was decreased in group III compared with group I. In Group II, 7 patients were complained the pain during surgery. CONCLUSIONS: Intrathecal fentanyl 10 microgram with bupivacaine 5 mg on spinal blockade provide reliable anesthesia for lower extremity surgery.

The dose-dependent effect of remifentanil for withdrawal responses on injection of recuronium in children

BACKGROUND: The injection of rocuronium causes pain and withdrawal responses. This study was designed to determine an appropriate dose of remifentanil to prevent the withdrawal responses associated with injection of rocuronium in children. METHODS: Fourty five ASA physical status I and II pediatric patients were randomly allocated into three groups; Group I (placebo; normal saline 3 ml, n = 15), Group II (remifentanil 0.3microg/kg, n = 15), Group III (remifentanil 0.5microg/kg, n = 15). After the induction of anesthesia with 5 mg/kg of thiopental sodium, patients in groups I, II, and III received normal saline 3 ml, remifentanil 0.3microg/kg, and remifentanil 0.5microg/kg, respectively. After one minute, rocuronium 0.6 mg/kg was injected over 10 seconds. The patient's response after injection was graded using a four-point scale. The patient's heart rate (HR), mean arterial pressure (MAP) were measured at pre-anesthesia (T0), 1 minute after injection of thiopental sodium (T1), test drug (T2), and rocuronium (T3). RESULTS: The incidence of withdrawal responses was 100%, 66.7%, and 20% in groups I, II, and III, respectively. In addition, the severity of withdrawal responses was lowest in group III. CONCLUSIONS: Remifentanil 0.5microg/kg was an appropriate dose to prevent the withdrawal responses on injecting rocuronium.

Thermoregulatory responses of sevoflurane, desflurane, and isoflurane during gynecologic laparoscopic surgery / 대한마취과학회지

BACKGROUND: Core temperature decreases rapidly after the induction of general anesthesia, because the heat is redistributed to peripheral tissues. Thermoregulatory responses of volatile anesthetics have been tested, but their effects have not been directly compared. Therefore, we evaluated the thermoregulatory responses to sevoflurane, desflurane, and isoflurane. METHODS: Sixty healthy patients scheduled for laparoscopic myomectomy or radical hysterectomy were allocated into three groups; Group S (sevoflurane, n = 20), Group D (desflurane, n = 20), and Group I (isoflurane, n = 20). Anesthesia was maintained with 1 minimum alveolar concentration (MAC) of sevoflurane, desflurane, and isoflurane in a 50/50 mixture of N2O/O2. Patients were maintained in a normovolemic and normocapnic state. The core temperature and forearm minus fingertip skin-temperature gradient (an index of peripheral vasoconstriction) were monitored after the induction of general anesthesia. RESULTS: Each of the seven patients given sevoflurane, desflurane, and isoflurane vasoconstricted at a core temperature of 35.3 +/- 0.5degrees C, 33.6 +/- 0.4degrees C, and 35.2 +/- 0.4degrees C, respectively. The vasoconstriction threshold was the lowest in patients anesthetized with desflurane. The core temperature gradient (Ti-Tf) was significantly higher in patients that were anesthetized with desflurane than in those that were anesthetized with sevoflurane or isoflurane. The core temperature of desflurane was significantly lower than that of sevoflurane or isoflurane 15 minutes after the induction of anesthesia until 180 minutes of anesthesia. CONCLUSIONS: These results indicate that the core temperature is maintained at a higher level in patients that have been anesthetized with sevoflurane or isoflurane than in those that have been anesthetized with desflurane.

The comparison of the relaxant effects of propofol, thiopental, ketamine, and etomidate on isolated rat uterine smooth muscle / 대한마취과학회지

BACKGROUND: Intravenous hypnotics are used in pregnancy, labor and delivery. The aim of the present study was to investigate and compare the relaxant effects of propofol, thiopental, ketamine, and etomidate on isolated rat uterine smooth muscles. METHODS: Uterine smooth muscle preparations were obtained from non-pregnant female rats. The uterus of the rat was dissected and cut into 10 mm strips. The muscle strips were bathed in Krebs solution. After spontaneous uterine contractile activity had been accomplished, propofol, ketamine, thiopental, and etomidate in various concentrations were added cumulatively to the baths and resting tension, active tension, and frequency of contration were recorded at each concentration of agents. EC(5), EC(25), EC(50), EC(75), and EC(95) of each drug on active tension and frequency of contraction were calculated using a probit model. RESULTS: Propofol, thiopental, and etomidate reduced uterine contractions in a concentration-dependent manner. Ketamine concentrations of 10(-7) to 10(-5) M augmented uterine contractions but ketamine concentrations of 10(-4) to 10(-3) M attenuated uterine contractions. The EC(50)'s of propofol, thiopental, ketamine, and etomidate on active tension were 1.56 x 10(-5) M, 4.97 x 10(-5) M, 3.52 x 10(-4) M, and 2.73 x 10(-5) M, respectively. CONCLUSIONS: All four intravenous hypnotics relaxed the uterine smooth muscle of rats except for ketamine in low concentrations (10(-7) to 10(-5) M). Propofol had the greatest relaxant effects on isolated rat uterine smooth muscle among these hypnotics. It seems that ketamine is a suitable obstetric hypnotic agent for hypovolemic parturients and propofol is a useful hypnotic agent for uterine relaxation during pregnancy.

The Effects of Propofol on the Contraction in the Rat Uterine Smooth Muscle / 대한마취과학회지

BACKGROUND: Propofol is an alternative to thiopental as an intravenous induction agent for cesarean section. It is also used as a sedative for supplementation of regional blockade during cesarean section. It has been reported that propofol relaxes not only vascular smooth muscle but also other smooth muscles. The aim of this study was to investigate the effect of propofol on rat uterine smooth muscle in an isolated preparation in the rat. METHODS: Uterine smooth muscle tissues were obtained from rats (n = 21). The muscle strips were suspended in tissue baths and isometric tension was recorded. After spontaneous or oxytocin induced activity had been accomplished in the buffer solution as a control, propofol (1 to 20microgram/ml) in fat emulsion was applied cumulatively to the bath and the effects were continuously recorded. RESULTS: In vitro, propofol induced a dose-dependent inhibition of spontaneous as well as oxytocin induced myometrial contractile activity. Propofol concentration of 1microgram/ml had no significant effects on the resting tension, active tention, and frequency of contraction developed by spontaneous and oxytocin induced uterine contractility. However, Complete muscular relaxations on spontaneous and oxytocin induced contractility were obtained at a concentration of 10microgram/ml and 20microgram/ml, respectively. CONCLUSIONS: Propofol inhibits spontaneous and oxytocin-induced uterine smooth muscle contractions in dose dependent pattern.

Effect of Intrathecal Fentanyl with Hyperbaric Bupivacaine on Unilateral Spinal Anesthesia for Knee Arthroscopy / 대한마취과학회지

BACKGROUND: Unilateral spinal anesthesia prolongs sensory blockade and provides hemodynamic stability. Intrathecal opioids enhance spinal anesthesia without prolonging motor recovery or hemodynamic side effects. The author evaluated the effect of intrathecal fentanyl on unilateral spinal blockade with hyperbaric bupivacaine for knee arthroscopy. METHODS: Thirty-six healthy patients undergoing unilateral knee arthroscopy randomly received unilateral spinal anesthesia with 0.5% hyperbaric bupivacaine 4 mg (Group I) or 0.5% hyperbaric bupivacaine 4 mg combined with fentanyl 10 microgram (Group II). A lateral decubitus position was maintained for 15 minutes after intrathecal injection. The level and duration of sensory and motor blockade were recorded. RESULTS: The regression time of sensory block by two segments on dependent site was prolonged on Group II more than Group I (P < 0.05). There was no significant difference between two groups in recovery time of sensory and motor block. Unilateral sensory block was observed in 18 patients in Group I (100%) and in 2 patients in Group II (11%). Hemodynamic side effects were minimal in both groups, but pruritus was observed in 6 patients in Group II (33%). CONCLUSIONS: Small dose of intrathecal fentanyl with bupivacaine unilateral spinal anesthesia prolonged the duration of sensory block on operated site, but did not increase side effects and the duration of motor block and recovery. But intrathecal fentanyl with bupivacaine made disturbance of successful unilateral spinal block by the sensory block of nonoperated site.

The Effects of Remifentanil to Prevent the Hemodynamic Changes to Mouth Gag Insertion in Tonsillectomy

BACKGROUND: The insertion of a mouth gag causes acute hemodynamic changes such as hypertension and tachycardia. Several adjuvant drugs have been used to attenuate such responses. The aim of this study was to determine the effects of remifentanil in preventing the hemodynamic changes associated with the insertion of mouth gag after a remifentanil injection. METHODS: Thirty children, ASA1 or 2, who were scheduled for elective surgery, were divided randomly into two groups; group I (placebo; normal saline 0.05 ml/kg, n = 15), and group II (remifentanil 0.05microg/kg, n = 15). After inducing general anesthesia with thiopental sodium (5 mg/kg) and rocuronium (0.06 mg/kg), anesthesia was maintained by the inhalation of sevoflurane 2 vol% in N2O/O2 (50/50) via an endotracheal tube. The patients in group I and II received normal saline 0.05 ml/kg, and remifentanil 0.05microg/kg 1 minute before inserting the mouth gag, respectively. The patients' blood pressure heart rate were measured before and after inserting mouth gag. RESULTS: The hemodynamic changes in group I were minimal after inserting the mouth gag compared with group II. CONCLUSIONS: Remifentanil is effective in attenuating the increase in blood pressure and heart rate after inserting a mouth gag.

The Effect of the Thoracic Epidural Analgesia on Postoperative Pain and Pulmonary Function Recovery after Thoracoscopic Surgery / 대한마취과학회지

BACKGROUND: The study was performed to evaluate the effect of the thoracic epidural analgesia on the postoperative pain and pulmonary function after thoracoscopic surgery. METHODS: Postoperative pain control consisted of continuous thoracic epidural infusion of normal saline in group 1 (Control group) and 0.125% bupivacaine mixed with fentanyl 5microgram/ml in group 2 (TEA group) added in single intercostal nerve block patient in sixty patients who had undergone elective thoracoscopic surgery. The visual analogue scale (VAS), Prince-Henry score (PHS) and pulmonary function (FVC and FEV1) were measured preoperatively and postoperatively at 4, 8, 12, 24, 48 hours. RESULTS: There were significant improvement of the degree of pain in both groups but TEA group was lower than control group during 48 hours except at postoperative 4 hours. Pulmonary function was decreased less and recovered faster in TEA group than control group during 48 hours (P < 0.05). CONCLUSIONS: Thoracic epidural analgesia added in single intercostal nerve block has a benefit on the recovery of the postoperative pulmonary function and also provide superior analgesia after thoracoscopic surgery when compared to single intercostal nerve block alone. The authors recommend thoracic epidural analgesia for patient undergoing thoracoscopic surgery who receive single intercostal nerve block.

The Dose-Dependent Analgesic Effect of Lidocaine for Pain on Injecting Rocuronium / 대한마취과학회지

BACKGROUND: Rocuronium produce intense discomfort on IV injection in conscious patients. The purpose of this study was to evaluate the incidence and severity of pain associated with IV injection of rocuronium in conscious patients and to determine the efficacy of different doses of IV lidocaine at minimizing injection pain. METHODS: The author evaluated 120 in-patients undergoing various elective surgeries. Patients were randomized into four groups of 30 patients for this blind, prospective study. After tourniquet application on the forearm, the patients were given saline (3 ml) (Group I, n = 30), lidocaine 20 mg (Group II, n = 30), lidocaine 40 mg (Group III, n = 30), or lidocaine 60 mg (Group IV, n = 30) diluted in a 3 ml solution. The occlusion was released after 20 seconds and rocuronium 0.6 mg/kg was injected over 10 seconds. The patients were observed and asked immediately if they had pain in the arm; responses were assessed. Five mg/kg of thiopental sodium was injected intravenously, 30 seconds after the administration of rocuronium. RESULTS: The incidence of pain was 86.7% in group I and was significantly lower group II (60.0%), group III (36.3%), and in IV (P <0.05). In addition, patients pretreated with lidocaine were less likely to suffer moderate to severe pain. But, pain incidences and severities were similar in those that received 40 mg or 60 mg of lidocaine. CONCLUSIONS: Lidocaine was effective at relieving rocuronium-induced and doses of 40 mg and 60 mg of lidocaine were most effective.

Partial Airway Obstruction with an Armored Tube by Swelling of the Inner Layer / 대한마취과학회지

An Armored tube is known to be the most effective in maintaining of airway patency during anesthesia in any position. Unfortunately, the tube itself may become the cause of airway obstruction. One of the known complications of the armored tube is a separation of the individual latex layers. This can be caused by herniation into the lumen. Diffusion of nitrous oxide into the inner hernia considerably intensifies the obstruction. The bubbles in the tube wall arise during manufacturing as well as during resterilization. A 62-year-old man with herniation of lumbar disc herniation was intubated with a 8.0 mm armored tube for general anesthesia. 30 minutes later, we experienced signs of partial endotracheal tube obstruction including high arterial PCO2 and inspiratory pressure in prone position. Then, tube suction with catheter was done and signs was slightly improved. But, 90 minutes later, passage of suction catheter was impossible. When operation was finished, patient was turned to supine position. We exchanged the tube with another tube and found inner wall herniation into the armored tube lumen caused by layer separation.

Electrosurgical Burn at the Site of EKG Electrode: A case report / 대한마취과학회지

In the operation room, members of the surgical team have the ultimate responsibility of safe guarding the patient from electrical devices. The electrosurgical unit is one instrument commonly used during surgical procedures. We have experienced accidental burning. Sixty-seven years-old patient received burn at the site of the ECG electrode which was caused by an electrocautery used in conjunction with electronic monitoring equipment. Although cutting and coagulation powers were very low, the normal size of the ECG electrodes led to the generation of a high current density. Prevention of interactions of this kind between properly functioning monitoring and surgical units requires good communication among all members of the operating room team and every electrical instruments should inspected, tested regularly.

Two Case Reports of Hepatitis Following Surgery / 대한마취과학회지

We had two cases of hepatitis developing after surgery. Case 1. A 47 year old male underwent surgery for amputation of the lower leg under enflurance anesthesia. Preoperative liver function test were slightly abnormal. On the 25th portoperative day, serum transaminases were elevated and the A/G ratio was reversed. On the 65th postoperative day, the liver function tests returned to near normal leve. Case 2. A 37 year old male underwent the first surgery for reduction of a pateliar fracture under spinal anesthesia. Preoperative serum transaminages were elevated and other laboratory findings at normal levels. On the 20th postoperative day serum transaminases were more elevated and on the 120th postoperative day, ti became normal again. This patient underwent the second surgery for removal of a K-wire under enflurane anesthesia and afterwards hepatitis recurred. On the 60th 2nd postoperative day LEFs became nearer to normal level and he was discharged in good health. Possible causes of the hepatitis in these cases were considered to be the preoperative liver disease, blood transfusion, the stress of the surgery and anesthesia.

The Effect of Intravenous Anesthesia with Ketamine on Respitatory System / 대한마취과학회지

An increasing interest in intravenous anesthetic techniques has resulted from the availability of more efficacious intravenous agents, possible discomfor of the patient on endotracheal intubation and the concern over anesthetic pollution in the operating room. This study was done to investigate the effect of intravenous anesthesia with ketamine on the respiratory system by comparing arterial blood gas analysis before and after the procedure. Analysis of arterial blood for PCO2, PO2, pH, and excess were carried out. Heart rate and blood pressure were monitored on 15 patients in ASA class l for diagnostic or short procedures. Each patient was premedicated with atropine 0.01mg/kg and valium 0.2mg/kg intramuscularly 30 minutes before the procedure. ketamine was administered intravenously 1.0~1.5 mg/kg or intramuscularly 3~5mg/kg for induction of anesthesia. The anesthesia was maintained with ketamine 0.5~1.0mg/kg and valium 0.1mg/kg ever 5 to 10 minutes. The results of this study showed that ketmine anesthesia seemed not to cause any untoward effect on respiratory function. In other words, ketamine seems to be a safe and good intravenous anesthetic agent for diagnostic or short surgical procedures.