| OBJECTIVE:1.To develop an lidocaine epidural administration death model , and observe three mainly vital signs and pathology of dogs after a fatal epidural anesthesia with lidocaine hydrochlorid. 2.To investigate the distribution of lidocaine in dead dogs to provide a scientific evidence for the forensic identification of the anesthesia accident caused by lidocaine. METHOD: 1. Animal model: Nine dogs were randomly allocated to two group,one group were given an epidural anesthesia with an even speed in five minutes with 75mg/kg weight of lidocaine hydrochloride (n=6 per group ) ;the other group were given the equate volume of physiological salt solution (n=3 per group ). 2. Record of vital signs: By a biological function system ,the vital signs such as electro cardia, blood pressure and respiration from beginning of the administration to the death of dogs were recorded. 3. Collection of samples: A dog died from the anesthesia was dissected as soon as its vital signs disappeared, and then its specimens—the brain, cerebrospinal fluid (CSF) in lateral ventricle, lumbar CSF in subarachnoid space, spinal cord (cervical spinal cord, thoracic spinal cord, lumbar spinal cord, sacrum spinal cord ), heart, lung, liver, spleen, kidney, bile, urine, heart blood, peripheral blood, muscle in injection location and muscle in no injection location —were collected and sampled immediately. 4. Pathology: The brain, spinal cord, cerebrum, heart, lung, liver, spleen and kidney were fixed with 4% formaldehyde, cut into sections and stained with a HE staining for a light microscopic examination. 5. Analysis: These obtained samples were extracted by ethyle ether. Analysis was performed with a GC equipped with a NPD and a GC-MS. The analytes identification were based on retention time in the chromatographic system coupled with the ion fragmentation spectrum in the mass spectrometer. The quatitative analysis was on an internal standard method . RESULTS: 1.The pupil decrease, salivate, dyspnoea, fidget, foam at the mouth, aphonia, muscle tremble occureed at 5~8 min after an epidural administration of lidocaine.During the anesthesia, paralysis of the four legs, rigidity, hyperkinesias, muscle tremble, incontinence of urine and excrement and extensive sensory occureed. 2. The time from the beginning of the administration to the disappearance of the electro cardiac, blood pressure and respiration was 33.2±9.1min,28.7±7.66min and 27.2±6.65min, respectively in the epidural anesthesia group. 3. The experimented dogs showed a pathology of the sudden death. 4. The concentrations detected in the urine, kidney, brain, heart, bile, lumbar spinal cord, muscle in injection location, sacrum spinal cord, spleen, thoracic spinal cord, cervical spinal cord, liver, muscle in no injection location, peripheral blood, heart blood, lumbar CSF in subarachnoid space, cerebrospinal fluid (CSF) in lateral ventricle and lung were 83.0±42ug/ml, 76.9±49.5ug/g, 48.3±29.6ug/g, 44.7±38.8ug/g, 30.4±17.2/ml, 27.8±14.7ug/g, 26.0±21.9ug/g, 25.7±13.9ug/g, 8.1±5.8ug/g, 24.1±14.7ug/g, 22.3±14.9ug/g, 20.2±15.7ug/g, 16.8±15.8ug/g, 16.1±14.6ug/ml, 14.7±12.7ug/ml, 14.3±10.3ug/ml, 12.2±8.9ug/ml and 24.8±17.7ug/g. Ratios of lidoocaine in the urine, kidney, brain, heart and bile to peripheral blood were 7.8±4.3, 5.9±2.5, 3.9±2, 2.8±1.4 and 4.1±3.5 respectively. CONCLUSION: 1. The study has established one dog model of the epidural anesthesia accident death. The changes of vital signs, symptom and pathology of experimental group dogs were similar to those of the case associated with an accidental anesthesia death. So the established model was available for the forensic identification study on the epidural anesthesia accident. 2. The distribution of lidocaine in epidural administration dogs can be applied to the forensic identification study on the epidural anesthesia accident . |
