Caruncle Single Injection Episcleral (Sub-Tenon) Anesthesia for Cataract Surgery: Mepivacaine Versus a Lidocaine-Bupivacaine Mixture

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.

[Hyaluronidase: Here we go again]

OBJECTIVE

To summarize the benefits and lateral effects of hyaluronidase (H) use in ophthalmologic anaesthesia and to address its unavailability in current practice in France.

DATA SOURCES

The Medline data bank and the Cochrane database were consulted. The keywords employed separately or in combination were: H, regional anaesthesia, ophthalmologic surgery, local aneasthetics myotoxicity, diplopia.

STUDY SELECTION

Original articles since 1949 were selected. We also selected isolated clinical cases according to their relevance compared with the existing literature.

DATA SYNTHESIS

H is a "spreading factor" of animal origin used as an adjuvant in ophthalmic anaesthesia for more than half a century. It allows a moderate better block quality with a slightly quicker onset. It also limits the acute intraocular pressure increase secondary to periocular injection and seems to have a protective effect against local anaesthetics myotoxicity resulting in postoperative strabismus. However, during these last 50 years, numerous studies often ended in divergent results.

CONCLUSION

H seems to be a useful adjuvant in ophthalmologic anaesthesia in spite of his current unavailability in France. Recombinant H could be the solution in the near future.

Complications of ophthalmic regional blocks: their treatment and prevention

Complications following ophthalmic regional anaesthesia are rare but are reported during both needle (intraconal and extraconal blocks) and blunt cannula (sub-Tenon's block) techniques. At present there is no perfect technique of ophthalmic regional anaesthesia. This article reports on the complications, treatment and prevention of commonly used ophthalmic regional blocks. Thorough knowledge of the measures required to deal with complications when they occur are of paramount importance for safe clinical practice.

A comparison of infero-nasal and infero-temporal sub-Tenon's block

BACKGROUND AND OBJECTIVE

Sub-Tenon's block is usually delivered by the infero-nasal (IN) approach, but occasionally this may not be possible. The infero-temporal (IT) approach has been described, but data is not available on its efficacy.

METHODS

One hundred patients undergoing cataract extraction were randomized to receive an IN or IT sub-Tenon's injection of lidocaine 2% with hyaluronidase 15 IU mL-1. Akinesia was assessed using the Brahma scale at 0, 2, 4, 6 and 8 min. Injection, intraoperative and postoperative pain scores (verbal analogue score, 0-10) were noted, along with the incidence of sub-conjunctival haemorrhage and chemosis.

RESULTS

There were no differences in patient characteristics data, or mean volume of administered local anaesthetic solution (3.3 (SD = 0.4) mL). There were no significant differences between groups in terms of onset of akinesia. Mean akinesia scores at 2, 4, 6 and 8 min were 2.7, 1.1, 0.4 and 0.2 for Group IN, compared to 2.2, 0.9, 0.8 and 0.3 for Group IT. Chemosis occurred in 14 patients in Group IN, compared to 22 in Group IT (P = 0.21).A sub-conjunctival haemorrhage was noted in 14 patients in Group IN and 19 patients in Group IT (P = 0.52). No patients required supplementary injections. Mean pain scores for the injection, intraoperatively and postoperatively were 0.9, 0 and 0 for Group IN, compared to 1.1, 0 and 0 for group IT. The surgeons scored all the blocks as 'good' except for one patient in each group.

CONCLUSIONS

The IT approach provides an equally rapid onset of block, without a significant increase in complications.

Sub-Tenon's block in cataract surgery--a comparison of 1% ropivacaine and a mixture of 2% lignocaine and 0.5% bupivacaine

Sub-Tenon's block for cataract surgery is an increasingly common technique. While this technique has been successfully applied, the optimal local anaesthetic solution is not known. This study was performed to assess any differences in anaesthesia and oculomotor block between 1% ropivacaine and a 2% lignocaine with 0.5% bupivacaine mixture. The results indicate that there was no difference noted in the clinical effect between the solutions.

A review of sub-Tenon's block

The place of sub-Tenon's block in ophthalmic surgery is now established. This block was introduced into clinical practice in the early 1990s as a simple, safe and effective technique. Since then, techniques have evolved, newer cannulae have been introduced and many complications, both minor as well as major, have been reported. This review deals with the recent developments in sub-Tenon's block.

Peribulbar anesthesia: a percutaneous single injection technique with a small volume of anesthetic

We evaluated the efficacy and safety of a single injection technique with a small volume of anesthetic for ocular peribulbar anesthesia. We included 857 patients undergoing various ophthalmic procedures. Anesthesia consisted of a medial percutaneous injection of 5-6.5 mL of 2% lidocaine. At 2 min 85.6% of the patients had a motor block of at least 50% and at 5 min 78.6% had a motor block >80%. After 5 min 100% of the patients had adequate surgical anesthesia. There were no serious block-related complications. The described technique is a simple and satisfactory alternative to the classical techniques.