Re-evaluation of hyaluronidase in peribulbar anaesthesia

Efficacy of adjuvants in ophthalmic regional anesthesia: A systematic review and network meta-analysis

PURPOSE

This network meta-analysis aims to determine the differences between adjuvants that are used in combination with local anesthetics for ophthalmic regional anesthesia.

DESIGN

Systematic review and network meta-analysis METHODS: A systematic literature search for randomized controlled trials, comparing the impact of adjuvants in ophthalmic regional anesthesia, in Embase, CENTRAL, MEDLINE and Web of Science was performed. Risk of bias was evaluated using the Cochrane risk of bias tool. Frequentist network meta-analysis was performed using a random effects model with saline as the comparator. Primary endpoints were the onset and the duration of sensory block and globe akinesia, as well as the duration of analgesia. Summary measure was the ratio of means (ROM). Secondary endpoints were the rates of side effects and adverse events.

RESULTS

39 trials were identified as eligible for network meta-analysis, including 3046 patients. 17 adjuvants were compared in the most extensive network (onset of globe akinesia). The addition of fentanyl (F), clonidine (C) or dexmedetomidine (D) showed the best overall results. Onset of sensory block: F 0.58 [CI 0.47-0.72], C 0.75 [0.63-0.88], D 0.71 [0.61-0.84], onset of globe akinesia: F 0.71 [0.61-0.82], C 0.70 [0.61-0.82], D 0.81 [0.71-0.92], duration of sensory block: F 1.20 [1.14-1.26], C 1.22 [1.18-1.27], D 1.44 [1.34-1.55], duration of globe akinesia: F 1.38 [1.22-1.57], C 1.45 [1.26-1.67], D 1.41 [1.24-1.59], duration analgesia: F 1.46 [1.33-1.60], C 1.78 [1.63-1.96], D 1.41 [1.28-1.56].

CONCLUSION

The addition of fentanyl, clonidine or dexmedetomidine showed beneficial effects regarding onset and duration of sensory block and globe akinesia.

Does the addition of hyaluronidase improve the quality of peribulbar anesthesia in cataract surgery? - A randomized double blinded study

Purpose

To determine the necessity of hyaluronidase as an anesthetic adjuvant for peribulbar anesthesia during cataract surgery and to assess differences in anesthetic outcomes in the absence of hyaluronidase.

Methods

In this double blinded randomized study, 202 patients reporting for surgery for senile cataract in their first eye under regional ocular anesthesia without pre-existing extra ocular movement restriction were randomly divided into 2 groups: Group 1 – anesthesia without hyaluronidase, Group 2 – anesthesia with 50 IU/ml Hyaluronidase. Peribulbar block with 5 ml of anesthetic mixture of 2% lignocaine with 1:200000 adrenaline and 0.5% bupivacaine with or without hyaluronidase was performed with 3 ml deposited in the infero-medial quadrant and 2 ml in the supero-medial quadrant followed by ocular massage. Surgeons’ score for akinesia, patients’ score for analgesia, augmentation of block if any and extra ocular movements on first post-operative day were compared between the groups.

Results

There was no statistically significant difference between the two groups in akinesia (p = 0.22, 0.68 and 0.98), analgesia (p = 0.44 and 0.09) or requirement of anesthetic augmentation (p = 0.3). Extraocular movement restriction was not noted in any patient. Onset of akinesia and analgesia was earlier in Group 2 (p = 0.004 and p = 0.005 respectively).

Conclusions

Hyaluronidase is not an essential adjuvant for peribulbar block for cataract surgeries. Appropriate deposition of a smaller volume of anesthetic agent and adequate ocular massage provide adequate and safe anesthesia.

Hyaluronidase in sub-Tenon's anesthesia for phacoemulsification, a double-blind randomized clinical trial

AIM

To investigate the effect of hyaluronidase use on the quality of sub-Tenon's anaesthesia for phacoemulsification.

METHODS

This was a randomized, double-blind clinical trial which was conducted at Nikookari Eye Hospital for 5 months. Forty-two eyes of candidates for phacoemulsification under sub-Tenon's anaesthesia were randomly allocated to two equal groups and received either 2 mL of lidocaine 2% solution with (LH), or without (L) addition of hyaluronidase (150IU/mL). Akinesia was assessed 15 minutes after sub-Tenon's injection. Patients and surgeon's satisfaction, as well as the postoperative pain (the visual analogue scale, VAS) were investigated after operation. The contingency tables (including the Chi-square or Fisher's exact tests, when appropriate) and parametric analysis (the independent samples t test) were used for statistical analysis.

RESULTS

Complete akinesia (33.3% vs 4.8%, P=0.04), as well as the patients (85.7% vs 57.1%, P=0.04) and surgeon's satisfaction (87.5% vs 52.4%, P=0.02) were significantly more frequent in LH than in L group. The mean VAS was significantly lower in the same group (1.90±1.45 vs 3.00±1.55, P=0.04).

CONCLUSION

Addition of hyaluronidase to lidocaine solution for sub-Tenon's anesthesia significantly improves the ocular akinesia, enhances the intra-operative patients and surgeons' satisfaction, and attenuates the postoperative pain.

[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.

Hyaluronidase reduces local anaesthetic volumes for sub-Tenon’s anaesthesia

BACKGROUND

Volumes of local anaesthetics for sub-Tenon's anaesthesia vary. Lower volumes produce less akinesia, whereas higher volumes increase chemosis and intra-ocular pressures. Hyaluronidase is often added to local anaesthetics to improve akinesia without increasing the volume of the injection, but this is controversial. This randomized, sequential allocation study examines the addition of hyaluronidase on the minimum local anaesthetic volume (MLAV) required for a sub-Tenon's block.

METHODS

Sixty-two patients having sub-Tenon's blocks for cataract surgery were randomized into two groups. The control group (n=31) received 2% w/v lidocaine and the study group (n=31) received 2% w/v lidocaine with hyaluronidase 15 IU ml(-1). Using parallel up-down sequential allocation from a 4 ml starting volume, the volumes in both groups were changed using a testing interval of 1 ml according to the quality of globe akinesia. The median effective local anaesthetic volume (MLAV) was calculated for both groups using probit regression.

RESULTS

The groups were similar for age, sex, and ocular axial length. The MLAV in the hyaluronidase group was 2.6 ml [95% confidence interval (CI), 2.1-3.l] and 6.4 ml (95% CI, 5.1-8.1) in the control group (P<0.002).

CONCLUSIONS

Hyaluronidase permits a significant 2.4-fold (95% CI, 1.8-3.4) reduction in MLAV for sub-Tenon's anaesthesia.

Safety and Efficacy of Sodium Bicarbonate versus Hyaluronidase in Peribulbar Anaesthesia

BACKGROUND

400 cases undergoing surgery for cataract under local anaesthesia were studied. Peribulbar anaesthesia involves injecting a mixture of 2% lignocaine, bupivicaine 0.5% and hyaluronidase into the peripheral space of the orbit through a single infero-lateral point. Sodium bicarbonate has been shown to reduce the time of onset of anaesthesia and pain perception when mixed with local anaesthetics.

METHODS

This study compared two groups of patients (200 each), one receiving hyaluronidase mixed anaesthetic and the other sodium bicarbonate buffered anaesthetic. The groups were compared for effectiveness of the anaesthesia, its onset, duration and the final visual outcome.

RESULTS AND CONCLUSION

Sodium bicarbonate was shown to reduce the time of onset and increase the successful block rate without any adverse affects.

Advances in ophthalmic regional anaesthesia

Although retrobulbar and peribulbar regional anaesthetic techniques are used (by both anaesthesiologists and ophthalmologists) in various types of eye surgery, topical anaesthesia of the conjunctiva and cornea, followed--as needed--by sub-Tenon's block, is now common in routine cataract surgery. Intracameral administration of local anaesthetic by the ophthalmologist is also performed. Sedation during ophthalmic surgery is distinctly lighter than for other surgery because it is essential that the patient remains alert and can cooperate with the surgeon. Continuous insufflation of oxygen-enriched air is needed to ascertain that CO2 has been flushed away. With a catheter placed into the nostril, the patient (whose head is draped and 'hidden') can have the end-tidal CO2 monitored. Finger index (FI), a palpation method that assesses the ease of performing retrobulbar block, is introduced. Because of the risk of life-threatening complications in ophthalmic regional anaesthesia, the services of an anaesthesiologist must be available and training of anaesthesia residents in ophthalmic regional anaesthesia is highly recommended.

L’anesthésie topique en chirurgie de la cataracte ambulatoire de l’adulte sans anesthésiste présent

To review the local anesthesia environment in France in adult out-patient cataract surgery. The author considers the presence or absence of an anesthesiologist in the operating room. The report shows that in many circumstances there is no need for an anesthesiologist if the following criteria are respected: the adult is fully informed, in rather good health, with no acute risk factors, and surgery is performed by a senior surgeon in a certified operating room. In France, a move toward more flexible regulations is expected, with a new cooperation between ophthalmologists and anesthesiologists that will lead to a new true risk/benefit/obligation ratio. Respect of the individual and safety remain crucial requirements making systematic generalizations impossible.

Effect of hyaluronidase on ocular motility in sub-Tenon's anesthesia: randomized controlled trial

PURPOSE

To assess the effect of hyaluronidase additive on the onset and degree of ocular akinesia in sub-Tenon's anesthesia for cataract surgery.

SETTING

Routine cataract operating list.

METHOD

This double-blind randomized controlled study comprised 100 patients who had phacoemulsification cataract surgery. Patients were randomized to 1 of 2 groups. For sub-Tenon's anesthesia, Group A received 5 mL lignocaine 2% with sodium hyaluronidase 150 IU/mL and Group B, 5 mL plain lignocaine 2%. Akinesia was assessed by scoring movement in the 6 positions of gaze. Scores ranged from 0 (complete akinesia) to 3 (no akinesia). Movements were measured at 30 seconds and 1, 3, 5, and 10 minutes. Changes in motility scores were compared by the Mann-Whitney U test.

RESULTS

There was no significant difference in akinesia between the 2 groups 30 seconds after the injection (P =.224); however, at 1 and 3 minutes, Group A achieved significantly better akinesia than Group B (P =.003 and P =.023, respectively). The median score after 3 minutes was 3.5 (interquartile range 0 to 7.5) in Group A and 7.0 (interquartile range 2.5 to 10.0) in Group B. There was no significant difference between the groups at 5 and 10 minutes (P =.225 and P =.831, respectively).

CONCLUSIONS

The addition of hyaluronidase in sub-Tenon's anesthesia significantly improved the rapidity of the onset of akinesia. This benefit disappeared over time; after 5 minutes the akinesia observed in the group receiving hyaluronidase was similar to that in the group receiving lignocaine alone. Thus, there appears to be no benefit to adding hyaluronidase to the anesthetic solution in terms of final ocular akinesia.

Efficacy of varying concentrations of hyaluronidase in peribulbar anaesthesia

We have compared the efficacy of adding varying concentrations of hyaluronidase to a standard mixture of 2% lidocaine and 1% ropivacaine to provide peribulbar anaesthesia for cataract surgery. We used (i) the time to adequate anaesthesia for surgery and (ii) ocular and eyelid movement scores at 8 min after block as clinical endpoints. Ninety patients were randomly allocated to receive 7-10 ml of equal volumes of 2% lidocaine and 1% ropivacaine without hyaluronidase or with hyaluronidase 15 IU ml(-1) or 150 IU ml(-1). Median time at which the block was adequate for surgery was 6 min in all groups (interquartile range 4-12 min). Median eyelid movement scores were similar in all groups, but the ocular movement scores at 8 min were significantly lower in the group which received hyaluronidase 150 IU ml(-1) than in the group not given hyaluronidase (P<0.03). There were no differences between groups in the incidence of minor complications. A high concentration of hyaluronidase resulted in a statistically significantly lower ocular movement score at 8 min; the clinical relevance of this finding is uncertain.

The methodologic quality of clinical trials on regional anesthesia for cataract surgery

OBJECTIVE

To assess the methodologic quality of published randomized trials of regional anesthesia management strategies for cataract surgery.

DESIGN

Literature review and analysis.

METHOD

We performed a systematic search of the literature to identify all articles pertaining to regional anesthesia for cataract surgery on adults. Overall quality scores and scores for individual methodologic domains were based on the evaluations of two investigators experienced in methodologic research who independently reviewed all relevant articles using a quality abstraction form.

MAIN OUTCOME MEASURES

Study quality in each of five domains: representativeness, bias and confounding, intervention description, outcomes and follow-up, and statistical quality and interpretation.

RESULTS

Eighty-two randomized clinical trials were identified with a mean overall quality score of 44%. The mean domain scores ranged from 37% for representativeness to 58% for outcomes and follow-up. Forty percent or fewer studies received the maximum score for reporting the setting, the population, and the start and end dates; describing the inclusion and exclusion criteria; adequately randomizing subjects; and adequately masking individuals participating in the study. Key outcomes were often inadequately reported, including the distribution of patient-reported pain scores and the mean surgical time.

CONCLUSIONS

Greater attention to methodologic quality and detailed reporting of study results will improve the ability of readers to interpret the results of clinical trials assessing regional anesthesia for cataract surgery.

Synthesis of the literature on the effectiveness of regional anesthesia for cataract surgery

OBJECTIVE

To synthesize the findings of the randomized trials of regional anesthesia management strategies for cataract surgery.

DESIGN

Literature review and analysis.

METHOD

The authors performed a systematic search of the literature to identify all articles pertaining to regional anesthesia during cataract surgery on adults. One investigator abstracted the content of each article onto a custom-designed form. A second investigator corroborated the findings. The evidence supporting the anesthesia approaches was graded by consensus as good, fair, poor, or insufficient.

MAIN OUTCOME MEASURES

Evidence supporting the effectiveness of different forms of regional anesthesia.

RESULTS

There was good evidence that retrobulbar and peribulbar blocks provide equivalent akinesia and pain control during cataract surgery. Additionally, sub-Tenon's blocks were at least as effective as retrobulbar and peribulbar blocks. There was good evidence that retrobulbar block provides better pain control during surgery than topical anesthesia, and there was fair evidence that peribulbar block provides better pain control than topical anesthesia.

CONCLUSIONS

This synthesis of the literature demonstrates that currently used approaches to anesthesia management provide adequate pain control for successful cataract surgery, but there is some variation in the effectiveness of the most commonly used techniques. Data are needed on patient preferences to determine the optimal strategies for anesthesia management during cataract surgery.

Hyaluronidase as an adjuvant in bupivacaine-lidocaine mixture for retrobulbar/peribulbar block

Hyaluronidase 7.5 IU/mL added to the local anesthetic improves peribulbar block, but smaller concentrations have not been shown to be effective. In this prospective, double-blinded study, 714 consecutive ocular surgery patients were randomized into three groups: no hyaluronidase (n = 241), hyaluronidase 3.75 IU/mL (n = 244), and hyaluronidase 7.5 IU/mL (n = 229). Retrobulbar/peribulbar block was performed with two injections of a 1:1 mixture of bupivacaine 0.75% and lidocaine 2%, 6-8 mL. Patient data were collected on demographics, initial volume of local anesthetic, need for supplementary block, and akinesia of the anesthetized eye. When hyaluronidase was used (3.75 or 7.5 IU/mL), the initial block was sufficient and the anesthetized eye was akinetic significantly more often than in the group without hyaluronidase. The hyaluronidase groups (3.75 and 7.5 IU/mL) did not differ significantly in any respect. We conclude that the addition of hyaluronidase 3.75 or 7.5 IU/mL improved the success of the initial retrobulbar/peribulbar block and akinesia and reduced the need for supplementary block.

IMPLICATIONS

We conclude that the addition of hyaluronidase 3.75 or 7.5 IU/mL improved the success of the initial retrobulbar/peribulbar block and akinesia and reduced the need for supplementary block.

Sub-Tenon's local anaesthesia: the effect of hyaluronidase

AIMS

A prospective, randomised, double blind study was used to investigate the effect of hyaluronidase on the quality of block achieved with sub-Tenon's local anaesthesia.

METHODS

150 patients scheduled for elective cataract surgery were randomly allocated to either sub-Tenon's block with 3 ml lignocaine 2%/adrenaline 1:200 000 alone or with the addition of 30 IU/ml of hyaluronidase. The blocks were assessed for degree of akinesia and reduction of eyelid movement, and also post-injection and postoperative pain scores.

RESULTS

Akinesia and reduction of eyelid movement measured 10 minutes after injection were significantly better in the group with hyaluronidase added to the anaesthetic solution. Postoperative pain scores were not significantly different between the two groups but the post-injection pain score was greater (marginally significant) in the group with hyaluronidase added.

CONCLUSION

The addition of hyaluronidase significantly improves the quality of the motor blockade achieved with sub-Tenon's local anaesthesia, but has no effect on the sensory blockade.

Anesthesia for cataract surgery

Developments of anesthesia for cataract surgery emerging from literature published during the scanning period include new drugs for sedation before general anesthesia and some discussion about monitoring. A few articles report on both improvements in and complications of peribulbar and retrobulbar injections. There are studies confirming the efficacy of sub-Tenon and topical anesthesia, sometimes associated with facial block. A tendency toward topical anesthesia emerged. Intraocular drug delivery was studied for toxicity both for cornea and for retina, in experimental and clinical settings.