Effects of high thoracic epidural anesthesia and local anesthetics on bronchial hyperreactivity

Bronchial hyperreactivity can cause life threatening bronchospasm after air way irritation. Therefore, endotracheal intubation is avoided in asthmatics when feasible. High thoracic epidural anesthesia can be used to avoid endo tracheal intubation and offers less postoperative pulmonary complications w hen compared to systemic postoperative analgesia. However, there are concer ns that it might also cause impaired ventilation by extended motor blockade , increased airway resistance, and increased bronchial reactivity because o f pulmonary sympathicolysis. Nevertheless, high thoracic epidural anesthesi a causes only a slight decrease in vital capacity and neither an increase i n airway resistance nor increased bronchial reactivity. In fact, it causes a decrease in bronchial reactivity in patients with bronchial hyperreactivi ty mostly due to the systemic effect of the local anesthetic. The attenuati on of bronchial hyperreactivity can be shown as a dose dependent effect of lidocaine and bupivacaine. The intravenous effect of lidocaine is comparabl e to the effect of a moderate dose of salbutamol and leads to an additive e ffect when both drugs are used in combination. Overall, high thoracic epidu ral anesthesia can be used safely in patients with bronchial hyperreactivit y and intravenous administration of lidocaine (1.5-2.0 mg . kg(-1)) can be used as a prophylactic treatment prior to airway instrumentation.