[Efficacy of 1% ropivacaine with and without hyaluronidase for peribulbar block]

To determine whether adding hyaluronidase to 1% ropivacaine without adrenalin enhances peribulbar anesthesia for cataract surgery with phacoemulsification.

Prospective double-blind study of 100 patients (ASA I-III) scheduled for outpatient cataract surgery with peribulbar blockade. The patients were randomized to two groups of 50 to receive either 10 mL of 1% ropivacaine without adrenalin and without hyaluronidase (Group R) or 1% ropivacaine without adrenalin but with 10 U/mL of hyaluronidase (Group RH). We compared the presence of complete akinesia, of adequacy of surgical conditions, and of the need for reinjection. For statistical analysis we used the chi-squared test and a Student t-test for independent samples, with statistical significance at 5%.

A block adequate for surgery was obtained in 98% of the patients in Group RH and in 86.7% of the patients in Group R (p = 0.043). Reinjection was necessary for 28.6% of Group R patients and 8.9% of Group RH patients (p = 0.14). Complete akinesia was similar in the two groups.

The greater efficacy of a peribulbar block with the addition of 10 U/mL of hyaluronidase to 1% ropivacaine without adrenalin, in comparison to 1% ropivacaine alone, was demonstrated by a lower rate of reinjection and ocular mobility, even though no statistically significant difference in either ocular or palpebral akinesia was found.