Peribulbar blockade with a short needle for phacoemulsification surgery

Transconjunctival approach to peribulbar block

As increasing numbers of anesthetists perform eye block anesthesia, thorough understandings of peribulbar injection techniques are important for safe practice. There is uncertainty in the literature regarding the optimum needle length, entry point, volume of injectate, and use of single vs double-injection techniques. A modified technique of peribulbar block anesthesia is presented, which offers increased safety, simplicity, low cost, and little change to instrumentation.

Anesthesia for pars plana vitrectomy with insulin needle, is it possible?

Peribulbar block is commonly used for ocular posterior segment surgery. This work aimed to compare the efficacy of using 12.5 mm to 25 mm standard needle length in performing single injection peribulbar block for retinal surgery. Peribulbar block was performed in 120 patients using either standard 25 mm or 12.5 mm 30 G needle (insulin needle). While applying digital pressure around the needle hub, 8–10 mL of local anesthetic are injected. Ocular movement was assessed at 5 and 10 min using simple akinesia score (0–8). If after 10 min score was >1, supplementary injection was given. Visual analogue scale (0–10) was used at the end of the procedure to assess surgeons' satisfaction and patients' intraoperative pain. No differences in akinesia score at 5 & 10 min (P = 0.34 and 0.36, resp.). Initial volume injected was comparable between groups (P = 0.31), however total volume of local anesthesia and supplementary injections were significantly higher in 12.5 mm group (P = 0.03 and 0.01, resp.). No difference as regard surgeons' satisfaction and patients' intraoperative pain (P = 1.0 and 0.18, resp.). Peribulbar block with 12.5 mm needle together with digital compression is a suitable alternative to the standard block with 25 mm needle length for retinal surgery.

Comparison between single-injection inferomedial and inferotemporal peribulbar blockades before cataract surgery

PURPOSE

To compare the efficacy and safety of single-injection inferomedial (IM) and conventional inferotemporal (IT) peribulbar blockades.

PATIENTS AND METHODS

This prospective randomized study included 200 patients who were randomly allocated into two equal groups (n = 100 patients); in the first group, patients received IM peribulbar injection (IM group), while IT peribulbar injection was performed for the second group (IT group). The measurement data were patient characteristics, number of patients who required supplementations, total anesthetic volume injected, surgeon's experience and any recordable complications.

RESULTS

The number of patients who required supplemental anesthetics due to inadequate block was significantly higher in the IT group (15 patients, 15%, vs. no patients, 0%, in the IM group). The total anesthetic volume injected was significantly lower in the IM group (5.6 ± 0.8 vs. 9.8 ± 0.7 ml in the IT group). Surgeon's satisfaction was significantly higher in the IM group (100 vs. 22% in the IT group). The incidences of complications were not significantly different between the two groups.

CONCLUSION

It is safe and effective to conduct single-injection IM peribulbar blockade using a small needle size and low anesthetic volume.

Effect of pressure-reducing devices on the quality of anterior orbit anesthesia

Needle length is an important consideration in the safe conduct of ophthalmic blocks. A shorter needle could be used to insert the local anesthetic before the globe equator in the anterior orbit and to direct the injectable posteriorly using Honan's balloon to produce the desired effect. However, the use of pressure-reducing devices is not advisable in procedures with impaired retinal blood flow. The aim of this work was to demonstrate the effect of ocular compression with a Honan's balloon on the quality of peribulbar anesthesia when a short needle was used. The blockades were performed in 120 patients using a 27 G, half-inch-long needle. The needle was inserted into the inferotemporal quadrant adherent to the inferior orbital notch. The 7 to 10 ml of local anesthetic solution, consisting of bupivacaine 0.5%, lidocaine 2% in a ratio of 3:2 with hyaluronidase 5 U/ml, was injected followed by application of Honan's balloon or no compression. Ocular akinesia was assessed 10 min later; if inadequate, supplementary anesthesia was provided. No difference was detected in terms of volume injected, supplementation, and akinesia score. Under the conditions of this study, Honan's balloon did not contribute to the quality of the anterior orbit anesthesia, and the technique can be successfully used when ocular compression is contraindicated.