SCIENTIFIC ARTICLE

 

Peribulbar block with ropivacaine: effects of hyaluronidase on blockade quality and intraocular pressure^*

 

Bloqueio peribulbar com ropivacaína: influência da hialuronidase sobre a qualidade do bloqueio e a pressão intra-ocular

 

Bloqueo peribulbar con ropivacaína: influencia de la hialuronidasa sobre la calidad del bloqueo y la presión intra-ocular

 

 

Paulo Sérgio Mateus Serzedo, TSA, M.D.^I; José Roberto Nociti, TSA, M.D.^II; Eduardo Barbin Zuccolotto, TSA, M.D.^I; Tatiana Lúcia Scalco, M.D.^III; Sérgio Borges Ferreira, M.D.^IV

^ICo-responsável pelo CET/SBA
^IIResponsável pelo CET/SBA da SCMRP
^IIIME₂ do CET/SBA da SCMRP
^IVOftalmologista Chefe do Instituto de Microcirurgia Ocular de Ribeirão Preto, SP

Correspondence

 

 

---

SUMMARY

BACKGROUND AND OBJECTIVES: Some studies have reported improved quality of peribulbar block by adding hyaluronidase to the local anesthetic solution while others claimed no beneficial effect. This study aimed at investigating the influence of hyaluronidase on intraocular pressure (IOP) and the quality of peribulbar block with 1% ropivacaine.
METHODS: Participated in this study 40 patients undergoing cataract surgery under peribulbar block who were randomly allocated to one of two groups according to the nature of the local anesthetic solution: Group A (n = 20), 1% ropivacaine (7 ml) supplemented with 50 IU.ml^-1 hyaluronidase; Group B (n = 20), 1% plain ropivacaine (7 ml). IOP measurements were performed by means of a Perkins applanation tonometer in four moments: M0 = before block (control); M1 = 1 min after block; M2 = 5 min after block; M3 = 15 min after block. Quality was evaluated by Nicoll's method based on eye motility decrease.
RESULTS: Mean IOP values (mmHg) before block (M0) were similar for both groups: 16,1 + 2.1 vs. 16.4 + 3.3. After blockade, mean IOP values were significantly lower in Group A as compared to Group B in the three moments after block: M1 = 11.7 + 2.4 vs. 17.9 + 3.6; M2 = 8.2 + 1.9 vs. 14.1 + 4.0; M3 = 5.3 + 2.1 vs. 10.2 + 3.1. IOP variations were also different within each group. In group A, mean values obtained in the three moments after block were significantly lower than control; in Group B, mean values significantly increased in M1 and were lower than control in M2 and M3. Mean eye motility scores were significantly lower in Group A as compared to Group B in M1 (2.55 vs. 3.65), M2 (0.25 vs. 2.2), and M3 (0.00 vs.1.00).
CONCLUSIONS: When 1% ropivacaine supplemented with 50 IU.ml^-1 hyaluronidase is used in peribulbar block, IOP values are lower and blockade quality is significantly better than when 1% plain ropivacaine is used.

Key Words: ANESTHETICS, Local: ropivacaine; ANESTHETIC TECHNIQUES, Regional: peribulbar; MEASUREMENT TECHNIQUES: intraocular pressure

---

RESUMO

JUSTIFICATIVA E OBJETIVOS: Alguns estudos têm relatado melhoria da qualidade do bloqueio peribulbar com o emprego de hialuronidase, enquanto outros concluem pela ausência de efeito. O objetivo deste estudo foi investigar a influência da hialuronidase sobre a pressão intra-ocular (PIO) e a qualidade do bloqueio peribulbar com ropivacaína a 1%.
MÉTODO: Quarenta pacientes submetidos à cirurgia de catarata foram distribuídos de forma aleatória em dois grupos e submetidos a bloqueio peribulbar com 7 ml de ropivacaína a 1% em técnica de dupla punção, com hialuronidase 50 UI.ml^-1 no Grupo A (n = 20) e sem hialuronidase no Grupo B (n = 20). As medidas de PIO foram realizadas com tonômetro de aplanação de Perkins em quatro momentos: M0 = antes do bloqueio (controle); M1 = 1 min após o bloqueio; M2 = 5 min após o bloqueio; M3 = 15 min após o bloqueio. A qualidade foi avaliada pelo método de Nicoll, baseado na redução da motilidade do globo ocular.
RESULTADOS: As médias de PIO (mmHg) antes do bloqueio foram semelhantes nos dois grupos: 16,1 + 2,1 (A) vs 16,4 + 3,3 (B). Após o bloqueio, as médias de PIO foram significativamente menores no Grupo A em relação ao Grupo B nos três momentos: M1 = 11,7 + 2,4 vs 17,9 + 3,6; M2 = 8,2 + 1,9 vs 14,1 + 4,0; M3 = 5,3 + 2,1 vs 10,2 + 3,1. O comportamento intragrupos também foi diferente. No Grupo A, as médias de PIO foram significativamente menores em relação ao controle nos três momentos após o bloqueio; no Grupo B a média de PIO elevou-se em M1 e foi significativamente inferior ao controle em M2 e M3. As médias para os índices de motilidade do globo ocular (Nicoll) foram significativamente menores no Grupo A em relação ao B nos três momentos: M1 = 2,55 vs 3,65; M2 = 0,25 vs 2,2; M3 = 0,00 vs 1,00.
CONCLUSÕES: Quando se emprega solução de ropivacaína a 1% adicionada de hialuronidase 50 UI.ml^-1 em bloqueio peribulbar, os valores da PIO são menores e a qualidade do bloqueio é melhor do que quando se utiliza ropivacaína a 1% sem hialuronidase.

Unitermos: ANESTÉSICOS, Local: ropivacaína; TÉCNICAS ANESTÉSICAS, Regional: peribulbar; TÉNICAS DE MEDIÇAO: pressão intra-ocular

---

RESUMEN

JUSTIFICATIVA Y OBJETIVOS: Algunos estudios han relatado mejoria de la calidad del bloqueo peribulbar con el uso de hialuronidasa, en cuanto otros han concluido por la ausencia del efecto. El objetivo de este estudio fue investigar la influencia de la hialuronidasa sobre la presión intra-ocular (PIO) y la calidad del bloqueo peribulbar con ropivacaína a 1%.
MÉTODO: Cuarenta pacientes sometidos a cirugía de catarata fueron distribuidos de forma aleatoria en dos grupos y sometidos a bloqueo peribulbar con 7 ml de ropivacaína a 1% en técnica de dupla punción, con hialuronidasa 50 UI.ml^-1 en el Grupo A (n = 20) y sin hialuronidasa en el Grupo B (n = 20). Las medidas de PIO fueron realizadas con tonómetro de aplanación de Perkins en cuatro momentos: M0 = antes del bloqueo (control); M1 = 1 min después del bloqueo; M2 = 5 min después del bloqueo; M3 = 15 min después del bloqueo. La calidad fue evaluada por el método de Nicoll, fundamentado en la reducción de la motilidad del globo ocular.
RESULTADOS: Las medias de PIO (mmHg) antes del bloqueo fueron semejantes en los dos grupos: 16,1 + 2,1 (A) vs 16,4 + 3,3 (B). Después del bloqueo, las medias de PIO fueron significativamente menores en el Grupo A en relación al Grupo B en los tres momentos: M1 = 11,7 + 2,4 vs 17,9 + 3,6; M2 = 8,2 + 1,9 vs 14,1 + 4,0; M3 = 5,3 + 2,1 vs 10,2 + 3,1. El comportamiento intragrupos también fue diferente. En el Grupo A, las medias de PIO fueron significativamente menores en relación al control en los tres momentos después del bloqueo; en el Grupo B la media de PIO se elevó en M1 y fue significativamente inferior al control en M2 e M3. Las medias para los índices de motilidad del globo ocular (Nicoll) fueron significativamente menores en el Grupo A en relación al B en los tres momentos: M1 = 2,55 vs 3,65; M2 = 0,25 vs 2,2; M3 = 0,00 vs 1,00.
CONCLUSIONES: Cuando se usa solución de ropivacaína a 1% adicionada de hialuronidasa 50 UI.ml^-1 en bloqueo peribulbar, los valores de la PIO son menores y la calidad del bloqueo es mejor de que cuando se utiliza ropivacaína a 1% sin hialuronidasa.

---

 

 

INTRODUCTION

Ropivacaine for peribulbar block in intraocular surgeries has provided good results, combining high quality with low morbidity ^1-3. Hyaluronidase is commonly associated to local anesthetics in this type of blockade aiming at facilitating its spread thanks to the hydrolysis of glucoside bindings within the hyaluronic acid forming the interstitial barrier⁴. Some studies have reported a marked improvement in blockade quality with the use of hyaluronidase ^5,6 while others concluded for the absence of such effect ⁷.

On the other hand, intraocular pressure (IOP) decrease after peribulbar block with ropivacaine associated to hyaluronidase has also been described ⁸.

This study aimed at investigating the possible influence of hyaluronidase on blockade and IOP after peribulbar block with ropivacaine.

 

METHODS

After the Hospital Research Ethics Committee approval participated in this study 40 patients of both genders, aged 41 to 95 years, physical status ASA I, II or III, scheduled for outpatient cataract surgery. Patients with glaucoma were excluded.

No premedication was administered and patients were randomly distributed in two groups, according to the presence or not of hyaluronidase in the ropivacaine solution used for peribulbar block.

Group A (n=20) - 1% ropivacaine with 50 IU.ml^-1 hyaluronidase

Group B (n=20) - 1% ropivacaine without hyaluronidase

Monitoring consisted of continuous ECG, pulse oximetry (SpO₂), non invasive systolic (SBP), diastolic (DBP) and mean blood pressure (MBP).

Peribulbar block was performed by the double puncture technique ¹ with a 25 x 6 mm needle (23 G-1) in a total volume of 7 ml injecting 4 ml through the lower eyelid in the junction of the lateral third with the two medial thirds of the orbital rime, and 3 ml through the upper eyelid in the upper-internal orbital border. After injection, an oculopression was applied on the closed eye with a Mcintyre weight for 10 minutes.

IOP was measured in four moments with a Perkins applanation tonometer by an independent observer (the surgeon himself) who did not know the solution's composition:

M0 - before blockade
M1 - 1 minute after blockade
M2 - 5 minutes after blockade
M3 - 15 minutes after blockade

Blockade quality was evaluated in moments M1, M2 and M3 through the method described by Nicoll et al ^1,9 based on decreased eye motility, considering 4 or below a successful rate.

Possible adverse events were looked for: pain at local anesthetics injection, hypotension (below 30% of baseline), hypertension (above 30% of control), bradycardia (HR < 50 bpm), tachycardia (HR > 120 bpm), dysrhythmia, nausea and vomiting.

Student's t test was used for statistical comparison between mean age and weight for both groups; Chi-square test compared gender. The two way analysis of variance parametric test was used to compare mean IOP between groups and within groups. To compare mean eye motility score (Nicoll) Mann-Whitney test was used between groups and Friedman test within each group. The level of significance of 5% (p < 0.05) was adopted for all tests.

 

RESULTS

Demographics data, which were homogeneous between groups, are shown in table I.

The frequency of eye motility scores (Nicoll) for both groups in all moments is shown in table II and their means in figure 1. Differences were significant both between and within groups.

IOP mean values are shown in table III and figure 2. Differences were statistically significant as of M1 both between and within groups.

Four Group B (20%) and one Group A (5%) patients complained of pain at injection. Three Group B (15%) and one Group A (5%) patients had hypertension episodes. One patient of each group (5%) needed sedation (intravenous diazepam). There were no other adverse effects.

 

DISCUSSION

Results have shown a more effective and better peribulbar block when 50 IU.ml^-1 hyaluronidase were associated to 1% ropivacaine. The addition of hyaluronidase has also influenced IOP variations. In patients submitted to the ropivacaine-hyaluronidase blockade, there has been a significant decrease in IOP as compared to the control group already in the first minute, which was more marked in subsequent measurements. In patients submitted to blockade with hyaluronidase-free ropivacaine, there has been a significant increase in IOP in the first minute which then decreased in subsequent measurements. But IOP means obtained for Group A patients (with hyaluronidase) were significantly lower as compared to Group B (without hyaluronidase) in all moments after blockade.

Such results are in line with other authors who observed a better peribulbar block with the addition of hyaluronidase to local anesthetics, using enzyme concentrations similar ¹⁰ or even lower ¹¹ than those used in this study.

Higher IOP levels in patients not receiving hyaluronidase were also detected by other authors ¹⁰, and this fact seems to be more related to the incomplete spread of local anesthetics within the periocular compartment. It is known that peribulbar block may cause a transient IOP increase due to the increase in intraorbital pressure caused by the anesthetic injection. However, IOP tends to return to its baseline value due to solution spread and extraocular muscles relaxation (secondary to blockade), thus decreasing external pressure on the eye ¹².

It is interesting to highlight that, as opposed to bupivacaine ¹⁰, the initial IOP increase with hyaluronidase-free ropivacaine was not maintained in subsequent measurements. This may be due to a more complete extraocular muscles relaxation with ropivacaine already observed in a previous comparative study with bupivacaine ¹³. Moreover, it is possible that the initial IOP increase caused by local anesthetics injection is further counterbalanced by a decrease in intraocular blood volume, secondary to the vasoconstrictor effect of ropivacaine ¹⁴, which is not true for bupivacaine which lacks such effect.

We concluded that when 1% ropivacaine is associated to 50 lU.ml^-1 hyaluronidase for peribulbar block, IOP values are lower and blockade quality evaluated by eye motility score, is better than when the same local anesthetics is used without hyaluronidase. The better local anesthetic spread within the periocular compartment provided by the characteristic effect of hyaluronidase, seems to contribute both for IOP decrease and to facilitate periocular nervous structures blockade by the anesthetic agent.

 

REFERENCES

01. Serzedo PSM, Nociti JR, Zuccolotto EB et al - Ropivacaína em bloqueio peribulbar: estudo comparativo com bupivacaína. Rev Bras Anestesiol, 1998;48:258-263.

02. Nicholson G, Sutton B, Hall GM - Ropivacaine for peribulbar anesthesia. Reg Anesth Pain Med, 1999;24:337-340.

03. Luchetti M, Magni G, Marraro G - A prospective randomized double-blind controlled study of ropivacaine 0.75% versus bupivacaine 0.5%-mepivacaine 2% for peribulbar anesthesia. Reg Anesth Pain Med, 2000;25:195-200.

04. Watson D - Hyaluronidase. Br J Anaesth, 1993;71:422-425.

05. Sarvela J, Nikki P - Hyaluronidase improves regional ophthalmic anaesthesia with etidocaine. Can J Anaesth, 1992;39:920-924.

06. Morsman CD, Holden R - The effects of adrenaline, hyaluronidase and age on peribulbar anaesthesia. Eye, 1992;6: 290-292.

07. Brydon CW, Basler M, Kerr WJ - An evaluation of two concentrations of hyaluronidase for supplementation of peribulbar anaesthesia. Anaesthesia, 1995;50:998-1000.

08. Serzedo PSM, Nociti JR, Zuccolotto EB et al - Pressão intraocular durante bloqueio peribulbar com ropivacaína a 1%. Rev Bras Anestesiol, 2000;50:251-253.

09. Nicoll JM, Treuren B, Acharya PA et al - Retrobulbar anesthesia: the role of hyaluronidase. Anesth Analg, 1986;65:1324-1328.

10. Dempsey GA, Barrett PJ, Kirby IJ - Hyaluronidase and peribulbar block. Br J Anaesth, 1997; 78:671-674.

11. Kallio H, Paloheimo M, Maunuksela EL - Is hyaluronidase effective as an adjuvant in retrobulbar/peribulbar block? Internat Monitor, 1998;10:50.

12. Johnson RW, Forrest FC - Anaesthesia for Ophthalmic Surgery, em: Prys-Roberts C, Brown Jr BR - International Practice of Anaesthesia, Oxford, Butterworth Heinemann, 1996;110:1-29.

13. Serzedo PSM, Nociti JR, Zuccolotto EB et al - Pressão intraocular durante bloqueio peribulbar com ropivacaína ou bupivacaína: estudo comparativo. Rev Bras Anestesiol, 2000;50:341-344.

14. Ishiyama T, Dohi S, Iida H et al - The effects of topical and intravenous ropivacaine on canine pial microcirculation. Anesth Analg, 1997;85:75-81.

 

 

Correspondence to:
Dr. José Roberto Nociti
Address: Rua Ayrton Roxo, 980
ZIP: 14025-270 City: Ribeirão Preto, Brazil
E-mail: carp@keynet.com.br

Submitted for publication August 28, 2000
Accepted for publication October 17, 2000

 

 

* Received from CET/SBA da Santa Casa de Misericórdia de Ribeirão Preto (SCMRP), SP

01. Serzedo PSM, Nociti JR, Zuccolotto EB et al - Ropivacaína em bloqueio peribulbar: estudo comparativo com bupivacaína. Rev Bras Anestesiol, 1998;48:258-263.         [ Links ]

02. Nicholson G, Sutton B, Hall GM - Ropivacaine for peribulbar anesthesia. Reg Anesth Pain Med, 1999;24:337-340.         [ Links ]

03. Luchetti M, Magni G, Marraro G - A prospective randomized double-blind controlled study of ropivacaine 0.75% versus bupivacaine 0.5%-mepivacaine 2% for peribulbar anesthesia. Reg Anesth Pain Med, 2000;25:195-200.         [ Links ]

04. Watson D - Hyaluronidase. Br J Anaesth, 1993;71:422-425.         [ Links ]

05. Sarvela J, Nikki P - Hyaluronidase improves regional ophthalmic anaesthesia with etidocaine. Can J Anaesth, 1992;39:920-924.         [ Links ]

06. Morsman CD, Holden R - The effects of adrenaline, hyaluronidase and age on peribulbar anaesthesia. Eye, 1992;6: 290-292.         [ Links ]

07. Brydon CW, Basler M, Kerr WJ - An evaluation of two concentrations of hyaluronidase for supplementation of peribulbar anaesthesia. Anaesthesia, 1995;50:998-1000.         [ Links ]

08. Serzedo PSM, Nociti JR, Zuccolotto EB et al - Pressão intraocular durante bloqueio peribulbar com ropivacaína a 1%. Rev Bras Anestesiol, 2000;50:251-253.         [ Links ]

09. Nicoll JM, Treuren B, Acharya PA et al - Retrobulbar anesthesia: the role of hyaluronidase. Anesth Analg, 1986;65:1324-1328.         [ Links ]

10. Dempsey GA, Barrett PJ, Kirby IJ - Hyaluronidase and peribulbar block. Br J Anaesth, 1997; 78:671-674.         [ Links ]

11. Kallio H, Paloheimo M, Maunuksela EL - Is hyaluronidase effective as an adjuvant in retrobulbar/peribulbar block? Internat Monitor, 1998;10:50.         [ Links ]

12. Johnson RW, Forrest FC - Anaesthesia for Ophthalmic Surgery, em: Prys-Roberts C, Brown Jr BR - International Practice of Anaesthesia, Oxford, Butterworth Heinemann, 1996;110:1-29.         [ Links ]

13. Serzedo PSM, Nociti JR, Zuccolotto EB et al - Pressão intraocular durante bloqueio peribulbar com ropivacaína ou bupivacaína: estudo comparativo. Rev Bras Anestesiol, 2000;50:341-344.         [ Links ]

14. Ishiyama T, Dohi S, Iida H et al - The effects of topical and intravenous ropivacaine on canine pial microcirculation. Anesth Analg, 1997;85:75-81.         [ Links ]