|Year : 2019 | Volume
| Issue : 4 | Page : 148-156
Articaine versus lidocaine with and without dexmedetomidine for peribulbar anesthesia in phacoemulsification
Esraa O Eissa1, Omyma S Mohamed1, Ahmed M Eid2, Ahmed Korani1
1 Department of Anesthiology, Minia University, Minia, Egypt
2 Department of Ophthalmology, Minia University, Minia, Egypt
|Date of Submission||08-Jul-2019|
|Date of Acceptance||04-Aug-2019|
|Date of Web Publication||17-Dec-2019|
MD Ahmed M Eid
Ophthalmology Department, Minia University Hospital, Minia 61111
Source of Support: None, Conflict of Interest: None
Background The aim of this study was to compare the use of articaine versus lidocaine either with or without dexmedetomidine for peribulbar anesthesia in phacoemulsification.
Patients and methods This is a prospective, randomized double-blind study that included 120 adult patients subjected to phacoemulsification with peribulbar anesthesia. They were randomly allocated into four groups: articaine (group 1, A), lidocaine (group 2, L), articaine–dexmedetomidine (group 3, AD), and lidocaine–dexmedetomidine (group 4, LD). Ocular akinesia was evaluated using Brahma scoring system. Pain assessment was carried out by four-point verbal rating score. Patient satisfaction and surgeon satisfaction were also recorded.
Results Regarding the ocular movement score, a statistically significant lower score was recorded in group 3 (AD) when compared with each of the other groups. Within each group, there was a significant decrease in eyelid score at 5, 10 min and end of surgery when compared with baseline score. Regarding the mean duration of globe akinesia, it was significantly longer in group 3 (AD) (139±20.4 min) in comparison with the other groups [group 4 (LD)=120.83±21.09 min, group 1 (A)=73±10.55 min, and group 2 (L)=50.33±4.9 min]. Patient satisfaction was significantly better in group 3 (AD) and in group 4 (LD). Surgeon’s satisfaction was significantly better in group 1 (A), group 3 (AD) and group 4 (LD) when compared with group 2 (L) and in group 1 (A) and group 3 (AD) in comparison with group 4 (LD), with the best quality detected in group 3 (AD).
Conclusion Articaine was superior over lidocaine for peribulbar block in achieving shorter onset and longer duration of globe akinesia and anesthesia. Addition of dexmedetomidine improved the quality of each.
Keywords: articaine, dexmedetomidine, peribulbar anesthesia, phacoemulsification
|How to cite this article:|
Eissa EO, Mohamed OS, Eid AM, Korani A. Articaine versus lidocaine with and without dexmedetomidine for peribulbar anesthesia in phacoemulsification. Delta J Ophthalmol 2019;20:148-56
|How to cite this URL:|
Eissa EO, Mohamed OS, Eid AM, Korani A. Articaine versus lidocaine with and without dexmedetomidine for peribulbar anesthesia in phacoemulsification. Delta J Ophthalmol [serial online] 2019 [cited 2020 Sep 22];20:148-56. Available from: http://www.djo.eg.net/text.asp?2019/20/4/148/273323
| Introduction|| |
Either a single anesthetic agent or a mixture of two agents is commonly used for peribulbar anesthesia. The choice of local anesthetics depends on the pharmacological properties of the drugs. The surgical requirements should be taken in consideration. When quick onset is needed, agents such as lidocaine, mepivacaine and articaine are used. On the contrary, ropivacaine and bupivacaine are used when prolonged effect and postoperative analgesia are needed .
Articaine is an amide local anesthetic that was first manufactured in 1960 and then investigated clinically in 1974. It is commonly used for dental surgery in most European countries. Articaine is chemically identical to prilocaine, but it contains an extra ester group that is hydrolyzed by plasma esterases. This leads to a shorter duration of action and lower risk of systemic toxicity . Moreover, it diffuses rapidly through tissues and has a wide therapeutic index. Therefore, it is widely used .
Many additives can be added to local anesthetics used for peribulbar anesthesia including clonidine, dexmedetomidine, hyaluronidase, sodium bicarbonate, muscle relaxants, and opioids to get rapid onset and longer duration . Dexmedetomidine is a selective α2 adrenoreceptor agonist. It provides dose-dependent sedation, analgesia, sympatholysis, and anxiolysis without relevant respiratory depression . Currently dexmedetomidine is used as an adjuvant to local anesthetic drugs in peripheral nerve block, brachial plexus block, and intrathecal anesthesia with satisfactory results .
In this study, the use of articaine was compared with lidocaine either with or without dexmedetomidine for peribulbar anesthesia used in phacoemulsification.
| Patients and methods|| |
This study was conducted in the Ophthalmology Department of Minia University Hospital during the period from January 2016 to January 2017. In a prospective, comparative, randomized, double-blind study, a total of 120 adult patients who were undergoing elective phacoemulsification cataract surgery with peribulbar anesthesia were included and randomly allocated into four groups:
- Group 1 [articaine (A)]: it received articaine 4% with 1 : 200 000 epinephrine (Artinibsa; Inibsa, Barcelona, Spain) and 150 IU hyaluronidase (Hyalase; Wockhardt, Wrexham, UK).
- Group 2 [lidocaine (L)]: it received lidocaine 2% with 1 : 200 000 epinephrine (Depocaine; Arab Company, Al Ameria Cairo Egypt) and 150 IU hyaluronidase.
- Group 3 [articaine–dexmedetomidine (AD)]: it received articaine 4% with 1 : 200 000 epinephrine, 50 µg of dexmedetomidine (Precedex; Hospira, Munich, Germany), and 150 IU hyaluronidase.
- Group 4 [lidocaine–dexmedetomidine (LD)]: it received lidocaine 2% with 1 : 200 000 epinephrine, 50 µg of dexmedetomidine, and 150 IU hyaluronidase.
All the previous mixtures were completed to a total final volume of 10 ml by adding normal saline.
Randomization was performed using computer-generated tables, and allocation was undertaken using sealed envelopes assignment by anesthetist not involved in clinical management or data collection who then prepared the anesthetic mixtures and drew it up in similar coded sterilized syringes of equal volumes and supplied it to the surgeon for peribulbar block in a double blinded fashion (neither the patients nor the surgeon or the anesthetist were aware of the group assignment). The protocol was opened after the study was completed.
All patients were subjected to complete preoperative assessment including history of any medical disease, history of allergy, drug intolerance, and previous anesthesia. General examination included vital signs, chest, heart, abdomen, and other systems. ECG and other routine investigations of elective surgery were done. Complete preoperative ophthalmological examination was done to exclude complicated cases.
In the operating room with the patient in supine position, after establishing arterial blood pressure, ECG, and peripheral oxygen saturation monitoring, an intravenous access was ensured by inserting an intravenous 22 G cannula. A nasal cannula was placed to administer oxygen at a flow rate of 3–4 l/h. Topical anesthesia of the conjunctiva and cornea was achieved by administration of two drops of 0.4% of benoxinate HCL (Benox; E.I.P.I.CO, Egypt). After sterilization of the eyelids and the surrounding areas with povidone-iodine 5% solution, transcutaneous peribulbar injection of 5 ml of the anesthetic solution was given at the junction of the lateral third and the medial two-thirds of the inferior orbital rim. A 22 mm, 25 G short bevel single-use needle (Egypt Spain for Medical Industry , Industry Zone 2 Borg Al Rab, Alexandria, A.R.E) was introduced along the inferior wall of the orbit with the sharp bevel facing the globe. The direction of injection was almost perpendicular to the frontal plane and parallel to the sagittal plane with the eye in the primary position. Injections were performed after gentle negative aspiration. Gentle digital massage of the eyeball was performed to facilitate diffusion of the local anesthetic. Then the patients were evaluated for ocular and eyelid movements using the scoring system described by Brahma et al.  at 1, 5, and 10 min after the injection; at the end of the surgery; and before discharge from the hospital. Ocular movements were scored for each direction of gaze in the superior, inferior, medial, and lateral directions, with a maximum score for each direction of three points and a possible total maximum score of 12 points. Lid akinesia was assessed by asking the patient to close his or her eyelids and squeezing them together maximally and graded as grade 0 if no movement, grade 1 if there was just a flicker, grade 2 if there was moderate movement, and grade 3 if there was full movement of the eyelids. The akinesia was considered inadequate for surgery if total eyeball movement score was 6 or higher. If this occurred, a second injection was performed via the medial or inferotemporal route according to surgeon assessment using 3 ml of the same anesthetic solution. A third injection was given if the block was still not sufficient at 10 min. The need for supplementary local anesthesia and the total volume of local anesthetic required was recorded.
Assessment of pain was done using four-point verbal rating score at just before surgical incision; at 5, 10, and 15 min during surgery; and at 1, 2, 6, and 24 h postoperatively. Breivik et al.  score was used with 0 score if no pain and 1, 2 and 3 scores for mild, moderate and severe pain, respectively. After completion of the surgery, the patient and the surgeon satisfaction of anesthesia was rated as poor, accepted, or perfect. Postoperatively, the patients were followed for recovery of akinesia, analgesic need, and incidence of any complications.
The study was approved by the Local Research Ethical Committee of the Faculty of Medicine, Minia University, and was adherent to the tents of the Declaration of Helsinki. Detailed informed consent was taken from all patients for the surgical procedures and for inclusion in the study after thorough explanation of the procedures and all possible risks and benefits.
The collected data were coded, tabulated, and statistically analyzed using the statistical package for the social sciences (SPSS software version 20; SPSS Inc., Chicago, Illinois, USA). Descriptive statistics were done for parametric quantitative data by mean, SD, and minimum and maximum of the range and for nonparametric quantitative data by median and interquartile range, whereas they were done for categorical data by number and percentage. Analyses were done for parametric quantitative data between the four groups using one-way analysis of variance test followed by post-hoc Tukey correction between each two groups and for nonparametric quantitative data between the three groups using Kruskal–Wallis test followed by Mann–Whitney test between each two groups. Analyses were done for parametric quantitative data within each group using paired sample t-test. Analyses were done for qualitative data using χ2-test (if the number per cell was>5) and Fisher exact test (if the number per cell was<5). The level of significance was taken at P value less than 0.05.
| Results|| |
The study involved 120 patients with an age range between 35 and 70 years. There were 54 (45%) males and 66 (55%) females. Demographic data and anesthetic volume are presented in [Table 1]. No statistically significant difference was present regarding age and sex between groups. However, regarding the local anesthetic volume, there was a statistically significantly lower volume in group 1 (A) and in group 3 (AD) in comparison with group 2 (L) and group 4 (LD) (P<0.001). There was a statistically significant difference in the need and frequency of supplementation of local anesthesia between groups (P<0.001), with the highest number of patients and more times of supplementations being in group 2 (L) followed by group 4 (LD), and then group 1 (A), and the lowest being in group 3 (AD). A significant difference was detected on comparing group 1 (A) and group 3 (AD), with each of group 2 (L) and group 4 (LD) and in comparing the latter two groups with each other ([Table 2]).
|Table 2 The need of local anesthetic supplementation among the studied groups|
Click here to view
Regarding the ocular movement score ([Table 3]), a statistically significantly lower score was recorded in group 3 (AD) when compared with each of group 1 (A) at 5 min and at the end of the surgery, to group 2 (L) at all-time intervals and to group 4 (LD) at 1 and 5 min and at the end of surgery, except at discharge time, which was comparable between all groups. The score was also significantly lower in both group 1 (A) and group 4 (LD) in comparison with group 2 (L) at 1 and 5 min and at the end of surgery and at 10 min in group 1 (A) only. No significant difference was recorded between group 1 (A) and group 4 (LD) at all-time intervals. On the contrary, no significant difference was detected in eyelid movement score at all-time intervals between the studied groups. However, within each group, there was a significant decrease in eyelid score at 5 and 10 min and at the end of surgery when compared with baseline score and a significant increase was detected at the time of discharge in all the studied groups ([Table 4]).
The mean time at which the eye was ready for surgery was 5±1.7 min in group 3 (AD), 6±1.36 min in group 1 (A), 7±1.87 min in group 4 (LD), and 10±2.017 min in group 2 (L), with a statistically significant difference (P<0.001).
The mean duration of globe akinesia was significantly longer in group 3 (139±20.4 min) in comparison with group 4 (120.83±21.09 min), group 1 (73±10.55 min), and group 2 (50.33±4.9 min). Moreover, it was significantly longer in group 1 in comparison with group 2 (P<0.001).
The number of patients who required postoperative analgesia is presented in [Figure 1]. It was significantly more in group 2 (30 patients) and in group 1 (22 patients) when compared with group 4 (17 patients) and group 3 (5) (P=0.001) and on comparing group 1 with group 3 (P=0.001) and group 3 with group 4 (P=0.047).
|Figure 1 Need for postoperative analgesia in studied groups. A, articaine; AD, articaine+dexmedetomidine; L, lidocaine; LD, lidocaine+dexmedetomidine.|
Click here to view
Apart from mild hypotension in group 3 (AD) and group 4 (LD) and conjunctival chemosis (which was significantly higher in group 2), no other complications were recorded ([Figure 2]). Patient satisfaction ([Figure 3]a) was significantly better in group 3 (AD), group 4 (LD), and group 1 (A) when compared with group 2 (L) (P<0.001). Moreover, it was significantly better in group 3 (AD) (P<0.001) and in group 4 (LD) (P=0.007) in comparison with group 1 (A), with no significant difference between group 3 (AD) and group 4 (LD) (P=0.261). Surgeon satisfaction ([Figure 3]b) was significantly better in group 1 (A), group 3 (AD), and group 4 (LD) when compared with group 2 (L) and with group 1 (A) and group 3 (AD) in comparison with group 4 (LD), with the best quality being detected in group 3 (AD), followed by group 1 (A) and then group 4 (LD), and finally, group 2 (L). However, no significant difference was recorded between group 3 (AD) and group 1 (A).
|Figure 2 Incidence of complications among the studied groups. A, articaine; AD, articaine+dexmedetomidine; L, lidocaine; LD, lidocaine+dexmedetomidine; NV, nausea vomiting.|
Click here to view
|Figure 3 (a): Patient satisfaction. P1: (A vs. L), P2: (A vs. AD), P3: (A vs. LD), P4: (L vs. AD), P5: (L vs. LD), and P6: (AD vs. LD). (b): Surgeon satisfaction. P1: (A vs. L), P2: (A vs. AD), P3: (A vs. LD), P4: (L vs. AD), P5: (L vs. LD), P6: (AD vs. LD). A, articaine; AD, articaine+dexmedetomidine; L, lidocaine; LD, lidocaine+dexmedetomidine.|
Click here to view
| Discussion|| |
Regarding the total local anesthetic volume and the need and frequency of supplementation, in this study, it was significantly lower in group 1 (A; 13.3%) and group 3 (AD; 10%) in comparison with group 2 (L; 93.3%) and group 4 (LD; 56.7%). This agrees with the results of Ozdemir et al. , who included in their study 58 patients with cataract allocated into two groups to receive either articaine 2% with epinephrine 1 : 200 000 or a mixture of equal parts of lidocaine 2% with epinephrine 1.25 : 100 000 and bupivacaine 0.5% through inferotemporal peribulbar injection, where the total volume of local anesthetic solution used was lower in the articaine group when compared with lidocaine/bupivacaine group (P<0.001). In addition, the number of patients who required a second or third injection was lower in the articaine group than the lidocaine/bupivacaine group. Khalil and Mohamed , performed elective cataract surgery for 60 patients under peribulbar anesthesia. Patients were allocated randomly into two groups of 30 patients each. Group A received 2% articaine as a local anesthetic agent. Group B received a mixture of 0.5% bupivacaine and 2% lidocaine. In group A (articaine group), only three (10%) patients needed a supplementary injection, whereas in group B (bupivacaine/lidocaine group), 14 (46.6%) patients needed a supplementary injection. The total volume of local anesthetic solution was less in group A than in group B (P<0.05). In this study, adding dexmedetomidine did not affect the total volume of local anesthetic used among the studied groups but decreased the number of patients who required supplementation and the frequency of injections in group 4 (LD) when compared with group 2 (L).
This study showed that articaine produced significantly better akinesia than lidocaine as indicated by a lower ocular movement score and rapid onset of globe akinesia in group 1 (A) compared with group 2 (L), and in group 3 (AD) when compared with group 4 (LD). These findings coincided with previously published research studies evaluating the efficacy of articaine compared with lidocaine/bupivacaine mixture, such as that of Khalil and Mohamed  who found that the onset was faster with articaine than with lidocaine/bupivacaine mixture, which showed delayed onset of action. In the study of Raman et al. , 65 patients were allocated to receive either 4% articaine or a mixture containing equal parts of 2% lidocaine and 0.5% levobupivacaine. Their study showed that akinesia was significantly higher in the articaine group and the surgeons rated it to be superior .
Addition of dexmedetomidine to both articaine and lidocaine accelerated the onset and improved akinesiain group 3 (AD) and group 4 (LD) when compared with each of group 1 (A) and group 2 (L). In addition, it improved the lidocaine action to be similar to that of articaine. These results were similar to those of Channabasappa et al. , where dexmedetomidine added to local anesthetics in two different doses shortened the onset and extended the duration of globe akinesia. On the contrary, El-Ozairy and Tharwat , enrolled 60 patients undergoing vitreoretinal surgery in a randomized, double-blind, controlled study. Patients were evenly assigned to three groups to receive one of three anesthetic solutions for peribulbar anesthesia. One group received 6 ml of 0.5% levobupivacaine with 10 IU/ml hyaluronidase in addition to 1 ml of normal saline. In the other two groups, patients received the same mixture but with replacement of the normal saline with 25 and 50 mcg dexmedetomidine, respectively. They reported that there was no significant difference regarding the onset of akinesia. In addition, Eskandr et al.  studied 60 patients, planned for phacoemulsification and allocated them into two groups. A control group received 2 ml of a mixture of 2% lidocaine and 0.5% bupivacaine, and dexmedetomidine group received 2 ml of a mixture of 2% lidocaine and 0.5% bupivacaine plus dexmedetomidine (0.5 μg/kg). They found no significant difference between the two groups (P=0.961) regarding the duration of akinesia. Akinesia score was better in dexmedetomidine group than in the control group, but the difference was statistically insignificant.
In terms of sensory block, faster onset of and prolonged duration of anesthesia were observed in articaine than lidocaine group, and adding dexmedetomidine improved both items. This agrees with the results of the study of Allman et al. , where 82 patients were randomly allocated into one of two groups to receive peribulbar anesthesia with either articaine or bupivacaine/lidocaine mixture. They reported complete sensory analgesia in all patients in the articaine group. In addition, Eskandr et al. , found that the onset of sensory block was significantly shorter in the dexmedetomidine group as compared with the control group (P<0.001) and the duration of analgesia or sensory block was significantly longer in the dexmedetomidine group as compared with the control group (P<0.001).
In this study, there was no significant difference among the studied groups in the onset and duration of eyelid akinesia and eyelid movement score. These findings coincide with Ozdemir et al. , where there was no difference between the groups in median eyelid movements at 1, 5, and 10 min and at the end of the surgery.
In this study, the lowest pain score was detected in group 3 (AD) followed by group 4 (LD), then group 1 (A), and lastly group 2 (L), as indicated by the time of first analgesic request. This implies that addition of dexmedetomidine improved pain score. This is in agreement with El Kabarity and Khashaba , who included 50 patients scheduled for elective vitreoretinal surgery under peribulbar anesthesia. Patients were divided into two groups. One group received equal mixture of bupivacaine 0.5% and lidocaine 2% with 1 mg/kg clonidine, whereas the other group received the same local anesthetic mixture supplemented with 1 mg/kg dexmedetomidine. They found that adding dexmedetomidine significantly prolonged the time to first analgesic request and subsequently less total analgesic requirement. In addition, Ozdemir et al. , found that the median pain score was significantly lower in the articaine group during the injection (P=0.004) and surgery (P=0.014), and Eskandr et al. , found that the duration of analgesia was significantly longer in the dexmedetomidine group as compared with the control group (P<0.001). On the contrary, Raman et al. , found that the analgesic effect of articaine was comparable with lidocaine/levobupivacaine anesthesia. This may be related to the use of a mixture of lidocaine/levobupivacaine for comparison with the enrolled rather than the use of only lidocaine in this study.
In this study, the complication rate was similar in all groups apart from the incidence of chemosis, which was higher in group 2 (L) when compared with each of group 1 (A), group 3 (AD), and group 4 (LD). The incidence of hypotension was higher in group 4 (LD) and group 3 (AD) when compared with group 1 (A) and group 2 (L). Allman et al. , found a higher frequency of complications in the lidocaine/bupivacaine group compared with the articaine group. On the contrary, Ozdemir et al. , did not demonstrate any significant differences in terms of complications between articaine and lidocaine/bupivacaine.
The best surgeon satisfaction, in this study, was observed in group 3 (AD) followed by group 1 (A), then group 4 (LD), and finally group 2 (L). Raman et al. , found that the surgeons rated superior akinesia with articaine, whereas in the study by Olmez et al. , no significant difference was appreciated the by surgeons between groups.
| Conclusion|| |
Articaine was superior over lidocaine for peribulbar block in cataract surgery in achieving shorter onset and longer duration of globe akinesia and anesthesia, higher sedation, lower pain, less analgesic requirement, and more patient and surgeon satisfaction. Addition of 50 μg of dexmedetomidine improved the quality of each of articaine and lidocaine. AD mixture was superior than all other groups in almost all parameters assessed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Borazan M, Karalezli A, Oto S, Algan C, Aydin Akova Y. Comparison of a bupivacaine 0.5% and lidocaine 2% mixture with levobupivacaine 0.75% and ropivacaine 1% in peribulbar anaesthesia for cataract surgery with phacoemulsification. Acta Ophthalmol Scand 2007; 85:844–847.
Oertel R, Rahn R, Kirch W. Clinical pharmacokinetics of articaine. Clin Pharmacokinet 1997; 33:417–425.
Wahl M, Schmitt M, Overton D. Injection pain of prilocaine plain, mepivacaine plain, articaine with epinephrine, and lidocaine with epinephrine. Gen Dent 2005; 54:168–171.
Abdellatif AA, El Shahawy MA, Ahmed AI, Almarakbi WA, Alhashemi JA. Effects of local low-dose rocuronium on the quality of peribulbar anesthesia for cataract surgery. Saudi J Anaesth 2011; 5:360–364.
Paris A, Tonner PH. Dexmedetomidine in anaesthesia. Curr Opin Anaesthesiol 2005; 18:412–418.
Gandhi R, Shah A, Patel I. Use of dexmedetomidine along with bupivacaine for brachial plexus block. Natl J Med Res 2012; 2:67–69.
Brahma AK, Pemberton CJ, Ayeko M, Morgan LH. Single medical injection peribulbar anesthesia using prilocaine. Anaesthesia 1994; 49:1003–1005.
Breivik EK, Björnsson GA, Skovlund E. A comparison of pain rating scales by sampling from clinical trial data. Clin J Pain 2000; 16:22–28.
Ozdemir M, Ozdemir G, Zencirci B, Oksuz H. Articaine versus lidocaine plus bupivacaine for peribulbar anaesthesia in cataract surgery. Br J Anaesth 2004; 92:231–234.
Khalil MMH, Mohamed IMI. Articaine versus bupivacaine/lidocaine mixture in episcleral peribulbar anesthesia for cataract surgery: a prospective randomized-controlled study. Ain Shams J Anesthesiol 2016; 9: 304–308.
Raman S, Barry J, Murjaneh S, Jacob J, Quinn A, Sturrock G et al.
Comparison of 4% articaine and 0.5% levobupivacaine/2% lidocaine mixture for sub-Tenon’s anesthesia in phacoemulsification cataract surgery: a randomized controlled trial. Br J Ophthalmol 2008; 92:496–499.
Channabasappa SM, Shetty VR, Dharmappa SK, Sarma J. Efficacy and safety of dexmedetomidine as an additive to local anesthetics in peribulbar block for cataract surgery. Anesth Essays Res 2013; 7:39–43. [Full text]
El-Ozairy HS, Tharwat AI. Comparative study of the effect of adding two different doses of dexmedetomidine to levobupivacaine/ hyaluronidase mixture on the peribulbar block in vitreoretinal surgery. Ain Shams J Anaesthesiol 2014; 7:393.
Eskandr AM, Elbakry AEAA, Elmorsy OA. Dexmedetomidine is an effective adjuvant to subtenon block in phacoemulsification cataract surgery. Egypt J Anaesth 2014; 30:261–266.
Allman K, Barker L, Werrett G, Gouws P, Sturrock G, Wilson I. Comparison of articaine and bupivacaine/lidocaine for peribulbar anaesthesia by inferotemporal injection. Br J Anesth 2002; 88:676–678.
El Kabarity R, Khashaba M. Dexmedetomidine versus clonidine as an adjuvant to peribulbar block in vitreoretinal surgery. Ain Shams J Anaesthesiol 2012; 5:288–292.
Allman KG, McFadyen JG, Armstrong J, Sturrock GD, Wilson IH. Comparison of articaine and bupivacaine/lidocaine for single medial canthus peribulbar anaesthesia. Br J Anaesth 2001; 87:584–587.
Olmez G, Cakmak SS, Caca I, Unlu MK. Intraocular pressure and quality of blockade in peribulbar anesthesia using ropivacaine or lidocaine with adrenaline: a double-blind randomized study. Tohoku J Exp Med 2004; 204:203–208.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4]