Bloqueio peribulbar com ropivacaína: influência da hialuronidase sobre a qualidade do bloqueio e a press?o intra-ocular

摘要

BACKGROUND AND OBJECTIVES: Some studies have reported improved quality of peribulbar block by adding hyaluronidase to the local anesthetic solution while others claimed no beneficial effect. This study aimed at investigating the influence of hyaluronidase on intraocular pressure (IOP) and the quality of peribulbar block with 1% ropivacaine. METHODS: Participated in this study 40 patients undergoing cataract surgery under peribulbar block who were randomly allocated to one of two groups according to the nature of the local anesthetic solution: Group A (n = 20), 1% ropivacaine (7 ml) supplemented with 50 IU.ml-1 hyaluronidase; Group B (n = 20), 1% plain ropivacaine (7 ml). IOP measurements were performed by means of a Perkins applanation tonometer in four moments: M0 = before block (control); M1 = 1 min after block; M2 = 5 min after block; M3 = 15 min after block. Quality was evaluated by Nicoll's method based on eye motility decrease. RESULTS: Mean IOP values (mmHg) before block (M0) were similar for both groups: 16,1 + 2.1 vs. 16.4 + 3.3. After blockade, mean IOP values were significantly lower in Group A as compared to Group B in the three moments after block: M1 = 11.7 + 2.4 vs. 17.9 + 3.6; M2 = 8.2 + 1.9 vs. 14.1 + 4.0; M3 = 5.3 + 2.1 vs. 10.2 + 3.1. IOP variations were also different within each group. In group A, mean values obtained in the three moments after block were significantly lower than control; in Group B, mean values significantly increased in M1 and were lower than control in M2 and M3. Mean eye motility scores were significantly lower in Group A as compared to Group B in M1 (2.55 vs. 3.65), M2 (0.25 vs. 2.2), and M3 (0.00 vs.1.00). CONCLUSIONS: When 1% ropivacaine supplemented with 50 IU.ml-1 hyaluronidase is used in peribulbar block, IOP values are lower and blockade quality is significantly better than when 1% plain ropivacaine is used.