Background and objectives: We carried out a prospective study in order to evaluate the efficacy and safety of peribulbar anaesthesia supplemented by a sub-Tenon injection in case of inadequate analgesia during vitreoretinal surgery.
Methods: We performed 300 consecutive vitreoretinal procedures. Patients received a mean volume of 17±4.5 ml of a mixture of etidocaine 1%, bupivacaine 0.50% and hyaluronidase (25 UI/ml).
Supplementation was represented by a sub-Tenon infiltration of lidocaine 2% (2 or 3 ml). This volume was not included in the mean volume.
Results: Analgesia was adequate throughout surgery without any supplementation in 85% of cases and with a sub-Tenon infiltration in 99%. Akinesia was complete in 82%, mild in 15% and absent in 3% of cases. The sub-Tenon injection was performed immediately before starting the procedure in 58% of cases and during the surgery with a delay of 80±21 min in 42%. Eleven patients (3.66%) were agitated during surgery and two of them needed a general anaesthesia to allow for the procedure. Generalised epilepsy was encountered in two patients (0.66%) immediately after the peribulbar injection in one patient and 15 min later in the other. The systolic blood pressure severely decreased between 60 to 70 mm Hg 40 min after the accomplishment of the peribulbar in 2 patients and at 90 min in 2 others.
Conclusion: Our results demonstrate that peribulbar anaesthesia alone offers excellent analgesia in 85% of patients and supplemented by a sub-Tenon injection in 99%.