ABSTRACT
Thoracic paravertebraI block has been advocated as a useful technique for breast surgery, this study was carried out on thirty adult female patients ASA I to evaluate the effect of ropivacaine thoracic paravertebral block on respiratory muscle strength, lung volumes and capacities and blood gases. Patients were scheduled for minor breast surgery. Respiratory functions and arterial blood gases were assessed before and after the block. Respiratory rate and oxygen saturation were assessed before and every 10 min intraoperative. The results of this study showed that, there was no significant change in vital capacity, in respiratory rate, in oxygen saturation and in arterial blood gases after the block compared with before the block. There was a significant decrease in forced vital capacity [FVC], in forced expiratory volume in one second [FEVI], in maximum inspiratory pressures [PI max], and in maximum expiratory pressure [PE max] after the block compared with the values before the block. In conclusion, single injection ropivacaine paravertebral block is an adequate anesthetic technique for minor breast surgery. It produced good efficient sensory block and extended post operative analgesia up to 150 +/- 19.97min from the onset of the block. Although it significantly decreased effort dependent respiratory functions, it produced mild respiratory muscle weakness that did not influence arterial blood gases, oxygen saturation or respiratory rate. It is recommended to use ropivacaine thoracic paravertebral block in minor breast surgery as a suitable ulternative to general anesthesia