The level of sensory blockade in spinal anesthesia is determined by the distribution of local anesthetics within cerebrospinal fluid (CSF) which is affected by the density of local anesthetics. Temperature is one of the factors which can influence the density of local anesthetics. The level of sensory blockade in spinal anesthesia may be altered by the density change of local anesthetics and by the time needed for thermal equilibration in CSF, depending on the storage temperature of local anesthetics. A study was conducted at Inchon Severance hospital on 20 elective surgery patients under spinal anesthesia, to compare the clinical differences between two groups stored at different temperatures. Group I was used 0.5% plain bupivacaine 3 ml (15 mg) stored in a refrigerator for longer than 24 hours and group II was used that stored in operating room temperature. The results were as follows : The level of sensory blockade in group II was significantly higher than that of group I, 3 minutes after spinal anesthesia by segmental level of sensory loss to pinprick test. The degree of motor blockade was significantly greater by Bromage scale in group II than in group I at 2 minutes after spinal anesthesia, but no significant difference was observed after 5 minutes. When 15 minutes elapsed, the complete motor blockade of lower extremities was observed in both groups. The onset of sensory block was significantly faster in group II(3.1+/-0.2 min) than in group I (5.2+/-0.5 min). The onset of maximum sensory block was also significantly faster in group II(9.5+/-0.5 min) than in group I (14.0+/-1.5 min). The maximum sensory block level was significantly higher in group II(T6.7+/-0.3 dermatome) than in group I (8.2+/-0.3 dermatome). However, the regression time was not significantly different between group I (122.0+/-3.8 min) and group II (117.2+/-6.0 min). The above results showed that when 0.5% plain bupivacaine stored in room temperature was used in spinal anesthesia, gave higher level of sensory blockade and faster onset than that kept in a refrigerator, which may due to the time difference needed for thermal equilibration in CSF.
Anesthesia, Spinal* ; Anesthetics, Local ; Bupivacaine* ; Cerebrospinal Fluid ; Humans ; Incheon ; Lower Extremity ; Operating Rooms

BACKGROUND: One of the most serious risks of epidural anesthesia is total spinal blockade from unintentional dural puncture. We evaluated the glucose test and the thiopental precipitation test to differentiate cerebrospinal fluid (CSF) from local anesthetics (LA). METHODS: (1) Experiment 1: CSF from twenty patients was serially diluted with 2% lidocaine or 0.5% bupivacaine. The ratio of CSF to LA-CSF mixture (CSF/(LA+CSF)) was from 0 to 1.0 at an interval of 0.1. We measured the glucose level of each sample with blood sugar meter. (2) Experiment 2: CSF from a hydrocephalus patient was serially diluted and its glucose level of each sample was measured in the same way as Experiment 1. We performed a urine stick test with each sample. Ten anesthetists blinded to the nature of the sample were asked to identify the results of the tests. (3) Experiment 3: Two milimeters of 2.5% thiopental was respectively mixed with local anesthetics, the amount of which was from 0.1 to 1.0 ml at an interval of 0.1 ml. Sixteen anesthetists blinded to the nature of sample were asked to identify the results of the tests. RESULTS: (1) Experiment 1: We can measure glucose level at CSF/(LA +CSF) of 0.5 in 2% lidocaine group and 0.6 in 0.5% bupivacaine group. (2) Experiment 2: We can detect glucose at lower level of CSF/(LA +CSF) by glucose meter than urine stick test (p<0.05). (3) At least 0.35 ml of 2% lidocaine and 0.29 ml of 0.5% bupivacaine was needed respectively to detect precipitation. CONCLUSION: We suggest that blood glucose meter be used instead of glucose test strip. For thiopental precipitation test, we have to adjust the amount of thiopental depending on the amount of test fluid.
Anesthesia, Epidural* ; Anesthetics, Local* ; Blood Glucose ; Bupivacaine ; Cerebrospinal Fluid* ; Glucose ; Humans ; Hydrocephalus ; Lidocaine ; Punctures ; Thiopental

BACKGROUND: One of the most serious risks of epidural anesthesia is total spinal blockade from unintentional dural puncture. We evaluated the glucose test and the thiopental precipitation test to differentiate cerebrospinal fluid (CSF) from local anesthetics (LA). METHODS: (1) Experiment 1: CSF from twenty patients was serially diluted with 2% lidocaine or 0.5% bupivacaine. The ratio of CSF to LA-CSF mixture (CSF/(LA+CSF)) was from 0 to 1.0 at an interval of 0.1. We measured the glucose level of each sample with blood sugar meter. (2) Experiment 2: CSF from a hydrocephalus patient was serially diluted and its glucose level of each sample was measured in the same way as Experiment 1. We performed a urine stick test with each sample. Ten anesthetists blinded to the nature of the sample were asked to identify the results of the tests. (3) Experiment 3: Two milimeters of 2.5% thiopental was respectively mixed with local anesthetics, the amount of which was from 0.1 to 1.0 ml at an interval of 0.1 ml. Sixteen anesthetists blinded to the nature of sample were asked to identify the results of the tests. RESULTS: (1) Experiment 1: We can measure glucose level at CSF/(LA +CSF) of 0.5 in 2% lidocaine group and 0.6 in 0.5% bupivacaine group. (2) Experiment 2: We can detect glucose at lower level of CSF/(LA +CSF) by glucose meter than urine stick test (p<0.05). (3) At least 0.35 ml of 2% lidocaine and 0.29 ml of 0.5% bupivacaine was needed respectively to detect precipitation. CONCLUSION: We suggest that blood glucose meter be used instead of glucose test strip. For thiopental precipitation test, we have to adjust the amount of thiopental depending on the amount of test fluid.
Anesthesia, Epidural* ; Anesthetics, Local* ; Blood Glucose ; Bupivacaine ; Cerebrospinal Fluid* ; Glucose ; Humans ; Hydrocephalus ; Lidocaine ; Punctures ; Thiopental

OBJECTIVE: To establish a rapid and simple gas chromatographic-mass spectric method for qualitative and quantitative analysis of lidocaine in blood and cerebrospinal fluid(CSF). METHODS: Following an acidification of HCl, blood or CSF was alkalinized with NaOH (pH=9) and extracted with ether for two times. Evaporated in a water bath and with an air velocity of nitrogen gas, extract was dissolved with ethanol and analyzed by a gas chromatographic-mass spectrum method, lidocaine was analyzed qualitatively and quantitatively by GC/MS (SIM:86, 58, 72, 87). RESULTS: Linear range of lidocaine detected in blood or CSF by this method is 1.0-60.0 microg x mL(-1) (r=0.9999), the minimum detected concentration of lidocaine was 0.02 microg x mL(-1) (S/N=3), recovery is at 85%-103%. This method was used in the determination of lidocaine in dog model died of the anesthesia with lidocaine. CONCLUSION This study provided a gas chromatographic-mass spectric analysis for lidocaine in blood and CSF. This method was more selective, little interferefering, more sensitivities and simpler. It could be used in the detection of lidocaine in biological fluids.
Anesthesia, Epidural ; Anesthetics, Local/cerebrospinal fluid* ; Animals ; Dogs ; Forensic Medicine ; Gas Chromatography-Mass Spectrometry/methods* ; Humans ; Injections, Intravenous ; Lidocaine/cerebrospinal fluid* ; Sensitivity and Specificity

BACKGROUND: Many factors determine the distribution of local anesthetics in the subarachnoid space. These major factors are dosage of local anesthetics, baricity of local anesthetics, position of patient, contour of vertebral column. The temperature of local anesthetics alters the baricity of local anesthetics. At 20oC, the density of 0.5% plain bupivacaine is 1.0003 and generally act as isobaric solution in the CSF. As its temperature lowers, its baricity increases. METHODS: Forty patients (A.S.A I and II) scheduled for lower extremity operation under spinal anesthesia were randomized into four groups; group I (37oC 0.5% bupivacaine, sitting position), group II (37oC 0.5% bupivacaine, 15o head-down position), group III (4oC 0.5% bupivacaine, sitting position), group IV (4oC 0.5% bupivacaine, 15o head-down position). The patients were placed in the sitting position (Group I, III) or lateral decubitus (Group II, IV) and dural puncture was performed at the L3-4 interspace using a midline approach (25-gauge Quincke spinal needle). A free flow of clear cerebrospinal fluid was obtained before administration of drug (37oC 0.5% bupivacaine in Group I, II and 4oC 0.5% bupivacaine in Group III, IV). Patients remained in the sitting position or 15o head-down position for 3 minutes after injection. Patients in each group received a solution that had been previously equilibrated in a stove to 37oC and in a refrigerator to 4oC for more than 1 day. Syringes used to administer the bupivacaine solution were also equilibrated to 37oC and 4oC, respectively. We checked sensory block level using pin-prick test at every 5 minutes. RESULTS: There was statistic significance in sensory block level between Group I, IV and Group II, III. The maximum sensory block level and the time to maximum cephalad spread of analgesia was the T4 level and 9.6 minutes in Group I, the T5 level and 13.5 minutes in Group IV compared to the T9 level and 21 minutes in Group II, the T10 level and 18 minutes in Group III. CONCLUSIONS: The temperature of 0.5% plain bupivacaine affects sensory block level and time to block. It is concluded that the temperature of the injected solution plays an important role in the sensory spread of 0.5% plain bupivacaine.
Analgesia ; Anesthesia, Spinal* ; Anesthetics, Local ; Bupivacaine* ; Cerebrospinal Fluid ; Humans ; Lower Extremity ; Posture* ; Punctures ; Spine ; Subarachnoid Space ; Syringes

BACKGROUND: Even though the effect of prehydration on the spinal anesthesia-induced hypotension has not yet been concluded, prehydration prior to spinal anesthesia is recommended in order to reduce the incidence and severity of hypotension. We investigated the effects of prehydration on hemodynamic change during spinal anesthesia with isobaric 0.5% tetracaine. METHODS: We prospectively performed this study on 96 patients who underwent elective transurethral surgery from October 2002 to January 2004. Patients were randomly allocated to receive either no prehydration or 10 ml/kg crystalloids administered over 10 15 min prior to spinal anesthesia. We compared dermatomal spreads of spinal anesthesia, hemodynamic parameters (blood pressure, heart rate), incidences of hypotension and bradycardia between two groups. RESULTS: Hemodynamic parameters, incidences of hypotension and bradycardia showed no statistically significant differences during spinal anesthesia between two groups. There were statistically significant differences in the dermatomal spread of sensory levels between two groups from 5 to 90 min after spinal anesthesia. Sensory block levels in prehydration group were statistically lower than no prehydration group. CONCLUSION: We hypothesized that prehydration can be one of factors that influence on dermatomal spread of local anesthetics in isobaric spinal anesthesia. The difference of dermatomal spread between two groups may be caused by brain blood barrier (BBB)-freely passing crystalloids, which may influence on the volume and density of cerebrospinal fluids. To verify this phenomenon found in our study, further investigation is still warranted.
Anesthesia, Spinal* ; Anesthetics, Local ; Blood-Brain Barrier ; Bradycardia ; Cerebrospinal Fluid ; Heart ; Hemodynamics ; Humans ; Hypotension ; Incidence ; Prospective Studies ; Tetracaine