Comparison of lignocaine 2% with adrenaline, bupivacaine 0.5% with or without hyaluronidase and a mixture of bupivacaine, lignocaine and hyaluronidase for peribulbar block analgesia

Use of hyaluronidase as an adjunct to local anaesthetic eye blocks to reduce intraoperative pain in adults

BACKGROUND

Hyaluronidase has been used over many decades as an adjunct to local anaesthetic solution to improve the speed of onset of eye blocks and to provide better akinesia and analgesia. With the evolution of modern eye surgery techniques, fast onset and akinesia are not essential requirements anymore. The assumption that the addition of hyaluronidase to local anaesthetic injections confers better analgesia for the patient needs to be examined. There has been no recent systematic review to provide evidence that hyaluronidase actually improves analgesia.

OBJECTIVES

To ascertain if adding hyaluronidase to local anaesthetic solutions for use in ophthalmic anaesthesia in adults results in a reduction of perceived pain during the operation and to assess harms, participant and surgical satisfaction, and economic impact.

SEARCH METHODS

We carried out systematic searches in Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and four other databases in June 2017. We searched the trial registers at www.ISRCTN.com, ClinicalTrials.gov and www.clinicaltrialsregister.eu for relevant trials. We imposed no language restrictions.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated the effect of hyaluronidase on pain experienced by adults during intraocular surgery using a rating scale.

DATA COLLECTION AND ANALYSIS

Two review authors (HR and KA) independently extracted data and assessed methodological quality using standard procedures as expected by Cochrane.

MAIN RESULTS

We included seven trials involving 500 participants that studied the effect of hyaluronidase on intraoperative pain. Four of the seven trials with 289 participants reported the primary outcome in a dichotomous manner, and we proceeded to meta-analyse the findings which showed a moderate heterogeneity that could not be explained (I2 = 41% ). The pooled risk ratio (RR) for these four trials was 0.83 with the 95% confidence interval ranging from 0.48 to 1.42. The reduction in intraoperative pain scores in the hyaluronidase group were not statistically significant. Among the three trials that reported the primary outcome in a continuous manner, the presence of missing data made it difficult to conduct a meta-analysis. To further explore the data, we imputed standard deviations for the other studies from another included RCT (Sedghipour 2012). However, this resulted in substantial heterogeneity between study estimates (I² = 76% ). The lack of reported relevant data in two of the three remaining trials made it difficult to assess the direction of effect in a clinical setting.Overall, there was no statistical difference regarding the intraoperative reduction of pain scores between the hyaluronidase and control group. All seven included trials had a low risk of bias.According to GRADE, we found the quality of evidence was low and downgraded the trials for serious risk of inconsistency and imprecision. Therefore, the results should be analysed with caution.Participant satisfaction scores were significantly higher in the hyaluronidase group in two high quality trials with 122 participants. Surgical satisfaction was also superior in two of three high quality trials involving 141 participants. According to GRADE, the quality of evidence was moderate for participant and surgical satisfaction as the trials were downgraded for imprecision due to the small sample sizes. The risk of bias in these trials was low.There was no reported harm due to the addition of hyaluronidase in any of the studies. No study reported on the cost of hyaluronidase in the context of eye surgery.

AUTHORS' CONCLUSIONS

The effects of adding hyaluronidase to local anaesthetic fluid on pain outcomes in people undergoing eye surgery are uncertain due to the low quality of evidence available. A well designed RCT is required to address inconsistency and imprecision among the studies and to determine the benefit of hyaluronidase to improve analgesia during eye surgery. Participant and surgical satisfaction is higher with hyaluronidase compared to the control groups, as demonstrated in moderate quality studies. There was no harm attributed to the use of hyaluronidase in any of the studies. Considering that harm was only rarely defined as an outcome measure, and the overall small number of participants, conclusions cannot be drawn about the incidence of harmful effects of hyaluronidase. None of the studies undertook cost calculations with regards to use of hyaluronidase in local anaesthetic eye blocks.

Guidelines for the use of local anesthesia in office-based dermatologic surgery

There are an increasing number and variety of dermatologic surgical procedures performed safely in the office setting. This evidence-based guideline addresses important clinical questions that arise regarding the use and safety of local anesthesia for dermatologic office-based procedures. In addition to recommendations for dermatologists, this guideline also takes into account patient preferences while optimizing their safety and quality of care. The clinical recommendations presented here are based on the best evidence available as well as expert opinion.

[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.

A comparison of two double-injection techniques for peribulbar block analgesia: infero-temporal plus supero-medial vs. infero-temporal plus medial-percaruncular

BACKGROUND

Combinations of infero-temporal and either supero-nasal ('inferior-superior') or medial percaruncular ('inferior-medial') injections are popular double-injection techniques for establishing peribulbar block analgesia. This study compared the efficacy of these two techniques in achieving ocular and lid akinesia.

METHODS

One hundred patients were randomized to receive inferior-superior or inferior-medial injections in a study in which injectate, injectate volumes, 5-min ocular akinesia scoring (0-8), lid scoring (0-2) and supplemental injection protocols were standardized. The numbers of supplemental injections required at each observation period and the total volume of injectate required to produce ocular and lid akinesia were compared.

RESULTS

The two test groups were demographically similar. The inferior-medial combination achieved greater ocular akinesia than the inferior-superior combination 5 min after the initial injections (mean score +/- standard deviation of 1.74 +/- 1.86 vs. 2.66 +/- 2.39; P < 0.05), with a reduced requirement for supplementary injections (3 vs. 23 supplementary injections; P < 0.025). The inferior-superior technique achieved greater lid akinesia at 5 min than the inferior-medial technique (mean score +/- standard deviation of 0.7 +/- 0.9 vs. 0.3 +/- 0.58; P < 0.005). A medial subconjunctival hemorrhage occurred in one patient in the inferior-medial group.

CONCLUSION

Compared with the inferior-superior technique, the inferior-medial combination achieved more rapid ocular akinesia with less need for supplementation, but induced less efficient lid akinesia and had a propensity to cause iatrogenic subconjunctival hemorrhage. The latter complication is considered by our surgeons to be a contraindication to the inferior-medial technique in patients undergoing trabeculectomy.

Bradycardia and hypertension in anticipation of, and exacerbated by, peribulbar block: a prospective audit

BACKGROUND

Changes in heart rate (HR), systolic arterial pressure (SAP) and diastolic arterial pressure (DAP) occur in anticipation of, and following, injection of a peribulbar local analgesic agent. We examined these changes in two groups of awake patients given a pre-medication of either hydroxyzine 1.0 mg/kg alone (control) or hydroxyzine 1.0 mg/kg with morphine 0.05 mg/kg.

METHODS

HR, SAP and DAP of 100 patients per group were monitored the day before surgery (baseline), every 5 min in the anesthesia holding room before peribulbar injection, every minute for the first 5 min after peribulbar injection and then every 5 min until transfer to the operating room. Within and between pre-medication group values of HR, SAP and DAP before and after peribulbar injection were compared with baseline.

RESULTS

The two groups of patients were similar. Before peribulbar injection, HR was unchanged in the hydroxyzine group, but 6% slower in those given morphine (P<0.01). After injection, HR slowed in both groups, by 5% and 7% (P<0.01, both comparisons), respectively. In anticipation of injection, SAP increased in both groups to 20% and 16% above baseline, respectively, and increased further after injection to 26% and 24% above baseline, respectively (P<0.001, all comparisons). In both groups, maximum SAP following injection exceeded maximum SAP before injection (P<0.02, both comparisons). DAP increased by 4% (P<0.05) in the hydroxyzine group before injection, and by 5% and 4%, respectively (P<0.005 and P<0.05, respectively) after peribulbar injection.

CONCLUSION

The audit reveals pronounced increases in SAP accompanied by lesser increases in DAP and a tendency to slowing of HR in awake patients in anticipation of peribulbar injections. Peribulbar injections cause further increases in blood pressure and mild bradycardia. These changes occur similarly in patients pre-medicated with hydroxyzine or hydroxyzine plus morphine. A mix of neuro-humoral influences (anxiety/catecholamine/baroreceptor/trigemino-vagal) are postulated as etiological.

An audit of peribulbar blockade using 15 mm, 25 mm and 37.5 mm needles, and sub-Tenon's injection*

The efficacy of peribulbar anaesthesia performed with short, medium and long needles, with sub-Tenon's injection as a control, was audited. Two hundred patients undergoing cataract surgery underwent peribulbar injection using 25G needles of the following lengths: 15 mm, 25 mm or 37.5 mm. Sub-Tenon's injections were performed with a curved 25-mm sub-Tenon anaesthesia cannula. The injection technique, ocular akinesia and analgesia scoring system, and supplementary injection protocols were standardised. After initial injections of local anaesthetic via the sub-Tenon's cannula or with 37.5 mm, 25 mm and 15 mm needles, supplementation was required in one (2%), 13 (26%), 22 (44%) and 32 (64%) of patients, respectively; the total number of supplementary injections required were 1, 16, 35 and 47, respectively. It is concluded that the efficacy of peribulbar anaesthesia depends upon the proximity of the deposition of local anaesthetic solution either to the globe or orbital apex. These data justify the classification of peribulbar anaesthesia into: circum-ocular (sub-Tenon's, episcleral), peri-ocular (anterior, superficial); peri-conal (posterior, deep) and apical (ultra-deep) for teaching purposes.

Diffusion and short-term efficacy of botulinum toxin A after the addition of hyaluronidase and its possible application for the treatment of axillary hyperhidrosis

BACKGROUND

Botulinum toxin adequately treats hyperkinetic facial lines and hyperhidrosis. Higher doses of botulinum toxin appear to enhance efficacy and longevity possibly through greater evenness of diffusion; however, recurrent treatments with higher doses are expensive.

OBJECTIVE

To admix botulinum toxin with hyaluronidase and to test whether there is maintenance of efficacy, a spread of effect, and possibly a decrease in required dose compared with botulinum toxin.

METHODS

Six patients participated in a double-blinded side-to-side comparison pilot study with photographic analysis for frontalis overactivity and Minor's iodine and gravimetric testing for axillary hyperhidrosis.

RESULTS

Initial efficacy of botulinum with admixed hyaluronic acid appeared maintained with possibly increased diffusion when hyaluronic acid is added. No difference was evident on short-term review of patients treated with 50 U of botulinum in one axilla compared with the contralateral side injected with 25 U with admixed hyaluronidase.

CONCLUSION

There may be a role for hyaluronic acid in aiding diffusion and decreasing the required dose of botulinum toxin in hyperhidrosis axillaris.

Effects of atracurium added to local anesthetics on akinesia in peribulbar block

BACKGROUND AND OBJECTIVES

Peribulbar anesthesia (PBA) is widely used in cataract surgery, but the onset time of akinesia is not as rapid as with retrobulbar block. The aim of this study was to evaluate whether addition of low-dose atracurium to the local anesthetic mixture has any effects on akinesia in PBA.

METHODS

Sixty adults undergoing cataract surgery were randomly allocated to receive either 8 mL of a lidocaine-bupivacaine mixture, plus 0.5 mL 0.9% NaCl (group I) or 8 mL of the same local anesthetic mixture plus 0.5 mL (5 mg) atracurium (group II). The level of akinesia was graded by a observer unaware of group assignment. The onset time and duration of akinesia were also recorded by an observer, again unaware of group assignment.

RESULTS

The onset time of complete akinesia in group II was significantly shorter than that in group I (P <.05). In group I, 86% of patients had an akinesia score of 0 (complete akinesia) in the first 10 minutes. The rate of complete akinesia was 93% in group II in the same period. This difference was not significant. The success rate of complete akinesia was 93% in group I and 100% in group II at the end of the measurement interval. None of the group II patients required supplementary block, while 2 patients in group I received additional injections for inadequate akinesia.

CONCLUSION

Atracurium added at a dose of 5 mg to a lidocaine-bupivacaine mixture for peribulbar block decreases the onset time of akinesia and provides better surgical conditions without obvious side-effects.

Whatʼs new in ophthalmic anaesthesia?

PURPOSE OF REVIEW

There have been many changes in ophthalmic anaesthesia in the past few years. This review charts recent trends in practice.

RECENT FINDINGS

Topical anaesthesia is gaining widespread use for ophthalmic surgery, but readers need to be aware that definitions vary widely; some 'topical' techniques also include intracameral injections and adjunctive sedation. There is now evidence on the relative effectiveness of different types of local anaesthesia from large systematic reviews. Furthermore, the notion is emerging that the traditional distinction between peribulbar and retrobulbar blocks may not be as clear-cut as previously thought. A new area of investigation is the effect of local blocks on pulsatile ocular blood flow. However, the risk of ocular ischaemia has yet to be quantified. Local anaesthesia has also been tried for posterior segment surgery with apparently successful results. The management of patients taking anticoagulants and anti-platelet agents has been examined, and it appears that there are risks not only in continuing therapy but also in stopping it peri-operatively. The decision thus has to be taken on the balance of risks.

SUMMARY

There have been significant further gains in our understanding of local anaesthetic eye blocks and the management of patients undergoing such procedures.

Ophthalmic regional anaesthesia

PURPOSE OF REVIEW

To summarize recent knowledge concerning ophthalmic regional anaesthesia.

RECENT FINDINGS

Ophthalmic regional anaesthesia has changed considerably over the past few years. Alternatives to retrobulbar anaesthesia have been proposed to reduce the number of complications without detriment to efficiency. Finally new local anaesthetics have been adopted and the indications have broadened, especially in vitroretineal surgery.

SUMMARY

New developments in ophthalmic regional anaesthesia are presented in this review. Different methods, indications and side effects are described in order to facilitate the clinician's choice, without any claim to single out an ideal technique.