Regional anesthesia
-
Regional anesthesia · Jul 1997
Comparative StudyIntraneural lidocaine uptake compared with analgesic differences between pregnant and nonpregnant rats.
Pregnant patients need less local anesthetic in order to obtain the same quality of functional block as nonpregnant patients. Our goal was to demonstrate a similarly increased functional susceptibility to local anesthetics in the awake pregnant rat during peripheral nerve block and to investigate the pharmacokinetic and/or pharmacodynamic mechanisms responsible for this phenomenon. ⋯ Block of peripheral neural function is prolonged in pregnant rats, and lidocaine content in the nerve is lower at a specific stage of neural block. These results are consistent with a pharmacodynamic mechanism for increased susceptibility to lidocaine neural block during pregnancy.
-
Interpleural analgesia is an effective method for pain relief after upper abdominal surgery. To examine whether the analgesic effect is obtained by block of the intercostal nerves, we assessed the analgesic efficacy of the block, the skin sensitivity, and indices of sympathetic outflow over the trunk. ⋯ The incomplete cutaneous sensory and sympathetic block indicates that the analgesic effect of interpleural analgesia cannot be explained by retrograde diffusion of the local anesthetic solution into the intercostal nerves alone.
-
Regional anesthesia · Jul 1997
Distribution of local anesthetic solution in retromediastinal block. Preliminary experimental results.
Interpleural anesthesia blocks pain perception from the thoracoabdominal wall without impairment of leg function. Bilateral interpleural anesthesia is not recommended because of possible bilateral impairment of respiratory function. Infiltration of the retromediastinum with local anesthetic might cause bilateral thoracoabdominal somatic block and block of sympathetic afferents from the abdominal cavity without impairing respiration. ⋯ Block of pain perception from the abdominal wall and cavity is possible by injection of local anesthetic into the retromediastinum via a catheter introduced through the esophageal diaphragm hiatus. The block would not be expected to impair respiratory or leg function. Its efficacy and safety have yet to be established.