Correlation between the Change of Mean Arterial Pressure and the Change of Percutaneous Oxygen Saturation in Patients with Tetralogy of Fallot / 대한마취과학회지

BACKGROUND: Hypoxia often occurs during anesthesia of patients with tetralogy of Fallot (TOF). The factors that determine pulmonary circulation and oxygenation in patient with TOF are the degree of obstruction of right ventricular outflow tract (RVOT), right ventricular filling pressure, systemic vascular resistance, loss of negative pleural cavity pressure by thoracotomy, change of pulmonary vascular resistance due to positive pressure ventilation and degree of arteriopulmonary collateral connection. Hence pulse oximetry is a noninvasive technique for measuring arterial O2 saturation continuously, this study examined the correlation between the change of percutaneous arterial oxygen saturation (delta SpO2) and the change of mean arterial pressure (delta MAP) using pulse oximetry in these patients. METHODS: Twenty pediatric patients undergoing modified Blalock-Taussig shunt or total corrective operation were prospectively investigated. Immediately after induction, baseline values of MAP and SpO2 were determined and if there were some changes in SpO2 from baseline during operation, MAP on that value of SpO2 were collected. If SpO2 reduced, patients were treated with infusion of fresh frozen plasma or pentastach (2-10 ml/kg), injection of phenylephrine (10 microgram/kg) or esmolol (0.5 mg/kg). RESULTS: Intravascular volume loading only was executed in 4 patients, intravascular volume loading and phenylephrine administration was executed in 11 patients, and intravascular volume loading, phenylephrine and beta-blocker administration was executed in 5 patients. There were no significant correlation between delta MAP and delta SpO2 from linear correlation and regression analysis (r=0.23, p<0.05). CONCLUSIONS: Because delta SpO2 were not closely related with delta MAP and above mentioned factors could act closely among each others, meticulous anesthetic management is necessary during palliative or total corrective operation in patients with TOF.

Spinal Anesthesia with Hyperbaric 1.5% Lidocaine and 1.5% Mepivacaine / 대한마취과학회지

BACKGROUND: Lidocaine has been used for spinal anesthesia in short surgical procedure. However, transient neurologic symptoms (TNS) frequently occur after spinal anesthesia with lidocaine. Mepivacaine which has a silimar duration of action and rare incidence of TNS may be an alternative to lidocaine for spinal anesthesia. This study was designed to compare the efficacy of hyperbaric 1.5% lidocaine and 1.5% mepivacaine for spinal anesthesia. METHODS: Sixty patients, ASA physical status I or II, scheduled for lower abdominal or lower extremity procedures under spinal anesthesia were randomly allocated into two groups. Lidocaine group received 2% lidocaine 75 mg with 10% dextrose 1.25 ml. Mepivacaine group received 2% mepivacaine 75 mg with 10% dextrose 1.25 ml. After intrathecal injection of the anesthetics, sensorimotor block and recovery, cardiovascular effect and quality of surgical anesthesia were evaluated. TNS was evaluated 1 day after the operation. RESULTS: Both groups were similar with regard to demographic data and surgical procedures. The onset of sensory and motor blocks was similar in both groups. Time to regression to L5 sensory level and complete resolution of motor blockade were significantly prolonged in mepivacaine group than in lidocaine group (p<0.05). The effect of cardiovascular system was similar in both groups. Fentanyl was required for 4 cases only in the lidocaine group. None of both groups developed TNS. CONCLUSIONS: Hyperbaric 1.5% mepivacaine produced longer duration of action than hyperbaric 1.5% lidocaine in spinal anesthesia. This study didn't prove what drug develops a higher incidence of TNS.

Comparison of Intranasal, Oral, and Rectal Midazolam for Premedication in Children / 대한마취과학회지

BACKGROUND: When appropriate premedication is required for pediatric patients, the route of drug administration and the patient's age may affect the drug response. This study was designed to evaluate the premedicative effects of intranasal, oral, and rectal midazolam in preschool (1~6 year) and school (6.1~10 year) ages. METHODS: One hundred fourteen children aged 1~10 years were randomly allocated into three groups to receive midazolam via intranasal (0.3 mg/kg), oral (1.0 mg/kg), or rectal (1.0 mg/kg) route. Sedation scores were evaluated at the arrival in preanesthetic room, drug administration, 5, 10, 20 and 30 min after drug administration, separation from parent, mask application, and induction with inhalational agent. Time to sedation scores of 3 and 4 and time to complete recovery from general anesthesia were recorded. RESULTS: At the drug administration, the incidence of crying was significantly higher in nasal group than in oral and rectal groups, especially in pre-school age group (87.5, 23.5. 40.9% for nasal, oral and rectal groups, respectively). At 5, 10 and 20 min after drug administration, sedation scores were significantly higher in nasal and rectal groups than in oral group. At separation, mask application and inhalational induction, sedation scores were significantly higher in oral and rectal groups than in nasal group. Time to sedation score of 3 and time to complete recovery were significantly longer in oral group than in nasal and rectal groups. CONCLUSIONS: In pre-school age, almost all the children cried at drug administration in nasal group, and onset and recovery were prolonged in oral group, so rectal route was suitable. In school age, nasal route was appropriate because of the lower frequency of crying at the drug administration and rapid onset and recovery. In overall age, rectal route was better because of the lower frequency of crying and rapid onset and recovery. This study suggests that administration route should be considered according to the age of pediatric patient to obtain appropriate premedication for pediatric patients.