BACKGROUND: Hemodilution reduces the concentration of clotting factors in blood and this may induce some degree of impairment of coagulation. But there are some evidence that hemodilution may induce a hypercoagulable state. The goal of this study is to investigate the changes of coagulation status during progressive hemodilution. METHODS: Whole Blood was diluted by 10% increment to 80% with 0.9% normal saline. At each 10% dilution blood coagulation status was analysed using thrombelastography (TEG) and was compared with that of an undiluted control specimen obtained concurrently from the same patients. RESULTS: Hemodilutions up to 40% decrease r and K times and increase values of MA and angle. Hemodilutions more than 70% increase r and K times and decrease values of MA and angle. CONCLUSIONS: Hemodilutions up to 40% increase coagulability and hemodilutions more than 70% decrease coagulability of whole blood in vitro.
Blood Coagulation ; Hemodilution* ; Humans ; Thrombelastography

BACKGROUND: Although degree of motor blockade during high thoracic spinal anesthesia is difficult to determine, pulmonary function may reflect the level of motor blockade. So we checked pulmonary function during spinal anesthesia with two different local anesthetic agents. METHODS: 50 patients, ASA PS 1-2, were randomly divided into two groups. After basal pulmonary function test (FVC: forced vital capacity, FEV1: forced expiratory volume in one second, PEFR: peak expiratory flow rate, PEP: peak expiratory pressure, PIP: peak inspiratory pressure.), the patients received spinal anesthesia with either 0.5% hyperbaric bupivacaine or 0.5% hyperbaric tetracaine. Thirty minutes after injection, level of sensory blockade was checked by pinprick test and pulmonary function test was performed. RESULTS: Almost all the values of pulmonary function reduced after spinal anesthesia, but the degrees of reduction were not differ in two groups except PEP, which reduced more profoundly in tetracaine group than bupivacaine group. CONCLUSIONS: It is more desirable that we use bupivacaine rather than tetracaine as spinal anesthetic agent in the patient with poor pulmonary function.
Anesthesia, Spinal* ; Anesthetics ; Bupivacaine* ; Forced Expiratory Volume ; Humans ; Peak Expiratory Flow Rate ; Respiratory Function Tests ; Tetracaine* ; Vital Capacity