[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.

[Dural puncture in obstetric analgesia. Epidemiologic features and therapeutic management]

OBJECTIVE

To assess the time of occurrence, circumstances and presenting symptoms of unintentional dural puncture (UDP), the location and intensity of postdural puncture headaches (PDPH), and the efficacy of their treatment by epidural blood-patch (EBP).

STUDY DESIGN

Cohort study.

PATIENTS

Cases of UDP recorded over a 4-year period in an obstetric anaesthesia unit.

METHODS

The following variables were studied: maternal age, weight and height, hour of occurrence and number of puncture attempts, existence of reflux of cerebrospinal fluid (CSF) through the needle, experience of the practitioners, subsequent modalities of obstetrical analgesia, frequency of occurrence, clinical characteristics and therapeutic management of PDPH. In case of EBP, the amount of blood and the efficacy of the procedure were also recorded.

RESULTS

Twenty-one patients presented with UDP (0.66%). No reflux of CSF was identified in nine cases. Most UDP occurred at the first or second attempt, usually when performed by a practitioner poorly trained in epidural analgesia in obstetrics. The risk of UDP was higher during night-time work (risk ratio: 3.0; 95% confidence interval: 1.1-8.0; p = 0.04). Subsequent analgesia was provided via the epidural route in 19 cases, subarachnoidal route in one, and intravenous route in one case. PDPH did not develop in two patients. Three patients were given prophylactic EPB, and 16 received curative EBP. A second EBP was required 24 h later in seven patients. One patient developed meralgia paresthetica following EBP.

CONCLUSION

In parturients, UDP usually results in PDPH. A rapid and effective treatment is required, mainly EBP. Another EBP is eventually necessary in some patients.

Caruncle single injection episcleral (Sub-tenon) anesthesia for cataract surgery: mepivacaine versus a lidocaine-bupivacaine mixture

We compared the quality of anesthesia provided by mepivacaine 2% or a mixture of lidocaine 2%-bupivacaine 0.5%, both with hyaluronidase, in caruncle single-injection episcleral (sub-Tenon) anesthesia. Sixty patients undergoing cataract surgery were included in this randomized, double-blinded study. The time to the onset of blockade, maximal akinesia, need for supplemental injection, and time to recovery were recorded. With mepivacaine, the time to onset was slightly shorter, and the akinesia score higher, than with the mixture. Although statistically significant, these differences are small. With mepivacaine, the time to recovery was shorter. We conclude that the reproducible short duration of the block may be an advantage in outpatient surgery.

IMPLICATIONS

We compared the classic mixture of lidocaine 2% plus bupivacaine 0.5% to mepivacaine 2% for caruncle episcleral (sub-Tenon) anesthesia for cataract surgery. Mepivacaine provided a more efficient block with a quicker onset and a quicker recovery. However, these differences were very small and were of little clinical interest.