The volumetric caudal epidural steroid injection has been advocated to facilitate the delivery of medications to the lesion site. This study was aimed to examine the actual spreading patterns of this technique, using epidurogram. A total of 32 patients with chronic low back pain accompanied by radiculopathy of various causes (degenerative spondylosis, herniated nucleus pulposus, spondylolisthesis, and spinal stenosis) were included. The volumetric caudal epidural injection of the 10 mL mixture of contrast medium 5 mL, 0.5% bupivacaine 1 mL, triamcinolone 1.5 mL (60 mg) and normal saline 25 mL was performed. Immediately after the cessation of the first spread, the subsequent solution of another 10 mL of contrast medium 5 mL, 0.5% bupivacaine 1 mL and normal saline 4 mL was injected. This procedure was repeated serially until the total volume to be 50 mL. Continuous fluoroscopic imaging was obtained after each injection. Average time taken to complete the study was 37 sec per every 10 mL. The spreading levels of the mixture were distributed mainly at mid to lower lumbar area in the majority of the patients. During the subsequent injections, the levels were not changed significantly. This was thought to be due to the minimal resistance in cephalad direction, anatomic variations and Starling effect of epidural space.
Adult ; Aged ; *Anesthesia, Epidural ; Anesthetics, Local/*pharmacokinetics ; Bupivacaine/*pharmacokinetics ; Chronic Disease ; Female ; Fluoroscopy ; Glucocorticoids, Synthetic/pharmacokinetics ; Human ; Low Back Pain/*drug therapy ; Male ; Middle Age ; Spinal Diseases/drug therapy ; Triamcinolone/pharmacokinetics

Spinal Anesthesia employing 0.5% plain bupivacaine was administered to 40 patients scheduled for lower limb or perineum sThe plasma concentrations and pharmacokinetic parameters of lidocaine were studied in 4 patients under general anesthesia(halothane, or enflurane-N20-O2) following the introduction of an 1% lidocaine endotracheal spray(1.5mg/kg) through an epidural catheter. Poak plasma lidocaine levels were reached in 5 to 15 minutes and were within the nontoxic range. The pharmacokinetics of lidocaine in these patients can be described by a two-compartment model with a rapid alpha distribution(T 1/2 alpha 8.66+/-2.24 min.), and an extensive apparent volume of idstribution(1.32+/-0.46 1/kg) similar to that observed in normal subjects. The half-life of absorption was 3.65+/-1.21 minutes. However, the elimination half-life(T 1/2 beta 173.25+/-32.41 min.) was prolonged and the total plasma clearance( 6.15+/-3.25 ml/min/kg) was decreased. This potent inhalation anesthetic agent may reduce the hepatic blood flow and would be expected to reduce the plasma clearance of lidocaine by reducing the delivery of plasma lidocaine. This study suggests that tracheal administration of lidocaine will produce effective plasma lidocaine levels in many clinical situations as will intravenous administration.
Absorption ; Administration, Intravenous ; Anesthesia, General* ; Anesthesia, Spinal ; Bupivacaine ; Catheters ; Half-Life ; Humans ; Inhalation ; Lidocaine* ; Lower Extremity ; Perineum ; Pharmacokinetics* ; Plasma

OBJECTIVE: To establish the models of postmortem redistribution(PMR) in dogs with epidural anesthesia and to investigate the effect of temperature on the PMR of Bupivacaine. METHODS: Eighteen male dogs were executed by epidural anesthesia with a dose of 5 mg/kg bupivacaine hydrochloride and randomly divided into three groups, room temperature (20-23 degrees C) group, 4 degrees C group and -20 degrees C group. The cardiac blood, peripheral blood, liver and cerebrum were collected at 0, 2, 4, 8, 24, 48, 72, 96, 120h postmortem. The contents of bupivacaine in those samples were analyzed by GC-NPD and GC-MS, the difference among three groups were compared. RESULTS: The bupivacaine PMR of room temperature group was evident and complex in cardiac blood, peripheral blood and cerebrum. The PMR of 4 degrees C group was weaker and slower than that of normal temperature group. The bupivacaine PMR of the -20 degrees C group was the weakest in three groups. CONCLUSION PMR of bupivacaine will happen in epidural anesthesia death dogs, but it could be delayed or prevent by low temperature storage.
Analgesia, Epidural ; Anesthetics, Local/pharmacokinetics* ; Animals ; Brain/metabolism* ; Bupivacaine/pharmacokinetics* ; Dogs ; Forensic Toxicology ; Gas Chromatography-Mass Spectrometry/methods* ; Liver/metabolism* ; Male ; Models, Animal ; Postmortem Changes ; Temperature ; Time Factors ; Tissue Distribution