Sub-Tenon S Block Versus Topical Anesthesia in Complicated Cataract Surgery

Transcription

1 Med. J. Cairo Univ., Vol. 77, No. 3, June: , Sub-Tenon S Block Versus Anesthesia in Comlicated Cataract Surgery GHADA A. EL-AWADY M.D.* and SHERIF R. GOHAR, F.R.C.S.** The Deartments of Anesthesiology, Intensive Care and Pain Relief, National Cancer Institute, Cairo University* and Ohthalmology, Dhahran Eye Secialist Hosital, Dammam City, Saudi Arabia**. Abstract Purose: This is a rosective randomized comarative blind study designed to comare erioerative ain control, comlications and efficacy of sub-tenon's versus toical in corneal hacoemulsification surgery and foldable intraocular lens (IOL) imlantation in comlicated cataract atients. Methods: Ninety-eight atients were allocated randomly to either sub-tenon's or toical grou with reset criteria after obtaining a written informed consent. All surgeries were erformed by one surgeon. Perioerative ain was assessed using a visual analog ain scale (VAS) and comared for both techniques, related events and comlications together with intraoerative surgical comlications were comared. Visual exerience of atients during hacoemulsification cataract surgery was assessed; atient as well as surgeon satisfaction was also noted. Results: Ninety seven out of ninety eight atients comleted the study after exclusion of one case. The data of the two grous were comarable in terms of age, sex, ASA (American Society of Anesthesiologists) state, axial length of the eye and duration of surgery. There were no statistical differences between the 2 study grous in the reoerative eye comlications. Forty five atients out of 49 atients in toical grou and four atients out of 48 in subtenon's grou exerienced no ain during administration of < There was significant difference in ain intensity during surgery, immediately and 3 h after surgery <0.05. Sub-tenon grou had significantly more related comlications than toical grou <0.05. There was no significant difference in the intraoerative comlications between the two grous under study. About 16 atients of the sub-tenon's grou had absolute akinesia during surgery as comared to none in toical grou < aears to result in greater visual awareness than sub-tenon's block = Sub-tenon's block was found satisfactory by 46 atients of cases and they would Author corresondence: Dr. Ghada A. El-Awady, Assistant rofessor, National Cancer Institute, Cairo University, Kasr El-Aini St. Fom El-Khalig, Cairo, Egyt, ghada elawady@yahoo.com choose the same anaesthesia for another rocedure while thirty two atients of atients subjected to toical were satisfied < Surgical conditions were graded to be otimal by the surgeon (none-minimal difficulties) in 46 atients subjected to sub-tenon's block and in 32 atients subjected to toical < Conclusion: In comlicated cataract cases undergoing corneal hacoemulsification and foldable lens imlantation, sub-tenon's was suerior to toical. Our results showed that more significant and analgesia was achieved with the sub-tenon's block, led to more convenient surgical conditions and enhanced atient and surgeon satisfaction without comromising atient's safety. Key Words: Cataract surgery Phacoemulsification Subtenon's anaesthesia anaesthesia Pain score Comlications. Introduction THE technique of sub-tenon's, using a blunt needle, rovides a safe yet reliable alternative, and has raidly become the rocedure of choice for ohthalmic anesthetists and surgeons as well. In 1992, Stevens [1] described a single quadrant aroach for administering local anaesthetic into the sub-tenon s sace. has become widely racticed throughout the world. It is a safe and reliable technique which is very well tolerated by atients. It can rovide adequate for a number of ohthalmic rocedures ranging from cataract surgery to vitreoretinal surgery. The sensory comonent of the block is often very effective; however, total akinesia may not always be obtained. Significant comlications are rare, but many atients will exerience a degree of sub-conjunctival hemorrhage and swelling. was first roosed by Fichman [2] as an attractive alternative to the traditional invasive eye blocks, resulting in faster visual recovery and high atient satisfaction. The advan- 237

2 238 Sub-Tenon s Block Versus Anesthesia tages of toical include its ease of alication, minimal or even absent discomfort on administration, raid onset of and elimination of the otential risks associated with other regional blocks [2-6]. In addition to all of these advantages, the technique is economical, with no cosmetic adverse effects, and allows immediate visual rehabilitation. However, toical only blocks the trigeminal nerve endings, roviding comlete analgesia of the eye, the atient's otic nerve and motor neurons are not affected, resulting in reserved ocular motility. Patient reference for toical is increasing steadily and enhancing all efforts to move away from more invasive forms of so that cataract surgery can be described as "minimally invasive". Patients are also, imressed with toical and 'no-atch' surgery. Although revious reorts [2-7] indicate that toical is safe and effective in most uncomlicated cataract rocedures, various studies [3,8] suggest that toical should not be considered in eyes with severe concomitant ocular athological features. Maniulation of the iris or stretching of the ciliary and zonular tissues, which may be inevitable during surgery in comlicated cases, could irritate the unanesthetized ciliary nerve endings and result in atient discomfort and inadvertent eye movements, comromising the overall safety of the rocedure. While this has led an increasing number of surgeons to administer sulemental anesthetic agents by intracameral injection or by addition to the irrigation fluid used during the intraocular hase of surgery, [5,6,9,10] this drawback has forced others [11] to abandon toical in favor of other regional block. Aim of the work: Our study was designed to analyze the outcome of Sub-tenon's Vs. toical alone without sedation in atients with comlicated cataract undergoing corneal hacoemulsification and foldable intraocular lens (IOL) imlantation. Patients and Methods After aroval of the Local Ethics Committee of Dhahran eye secialist hosital (Tertiary centre), Damam city, Saudi Arabia, a randomized comarative blind study encountered 98 surgical rocedures erformed by one surgeon from March 2007 to December Eligible Patients were over 30 years old and less than 85 years American Society of Anesthesiologists hysical status (ASA) class I III, undergoing elective cataract surgery under local anaesthesia were recruited in the study. Those with active ocular infection, allergies to hyaluronidase or local anesthetics, re-existing extraocular muscle alsies, communication difficulties, over anxious atients and those with acute resiratory disease, atients refusing local anaesthesia or when the decubitus was imossible were excluded from the study. After obtaining written informed consent, articiants were allocated into two grous using sealed enveloe method; sub-tenon's block grou (STB) 49 atients or toical grou (TA) 49 atients. All the atients articiated in the study had 0ne of the eye comorbidities as: axial hyeroia (<21.0 mm), axial myoia ( >_26 mm), osterior synechia, oor uillary dilation ( < 3 mm), uveitis or revious intraocular surgery (glaucoma surgery, eriheral iridectomy, or membrane eeling and ars lana vitrectomy). At the room, monitoring included ECG, ulse oxymeter, and non-invasive arterial blood ressure. No sedation was used. The conjunctiva and area surrounding the eye were ainted with an aqueous iodine solution. All sub-tenon's blocks used the inferonasal route and were erformed using a 19 G Visitec sub-tenon cannula. After draing, a lid seculum was alied and two dros of toical 4% amethocaine were instilled. The atient was asked to look uwards and outwards. Blunt Westcott's scissors were used to make a small nick on both, the conjunctiva and the tenon s casule in the inferonasal quadrant, five to six mm from limbus, and then the scissor created a ath in the subtenon sace through the nick. Conjunctival forces were used to gri the conjunctiva and a subtenon cannula was then inserted on to the sclera guided along with the contour of the globe. 4-5ml of a mixture of 2ml of 2% lidocaine hydrochloride with einehrine 1:10 000, 2ml of 5% buivacaine and hyaluronidase 30 units/ ml was injected slowly in the osterior subtenon sace. After the sub-tenon's injection, the eye was closed and a digital massage was alied for 5 min, then globe akinesia was assessed. was achieved by instilling four dros of amethocaine 1% over a 30 minute- Interval reoeratively, the surgeon injected 0.2ml rilocaine 2% subconjunctivally at the incision site immediately before surgery. All atients in both grous did not receive any erioerative sedation or drugs that might imair their cognitive function. The Surgeon used a scleral tunnel incision, continuous curvilinear casulorhexis, bimanual nucleofractis hacoemulsification, asiration of cortical remnants, and insertion of a 5.0 mm olymethylmethacrylate intraocular lens into the ca-

3 Ghada A. El-Awady & Sherif R. Gohar 239 sular bag. The oerating microscoe emloyed coaxial illumination with two light sources (Zeiss system). Intraocular ressure (IOP) was measured before and 1 and 10 minutes after. The motility of the rectus muscles was evaluated before and minutes after the sub-tenon injection, and the atient's anxiety level was recorded immediately after. Age, sex, ASA PS, gender, axial length of the eye, and duration of surgery were recorded. Surgery and related comlications and the sulemental analgesia for the eye used by the surgeon were also recorded. Pain was assessed during conduction of, intraoeratively, immediately and 3 hours ostoeratively using Visual analog sore. Patients were asked to grade ain intensity from 0 (no ain) to 10 (worst imaginable ain). Visual awareness during surgery was assessed by asking the atients 10 minutes after the comletion of surgery to describe their visual exerience and the accetability of this exerience. Patient satisfaction after surgery was assessed by asking whether the alied tye of would be their referred tye in further eye surgery. The surgeon also graded the difficulties' he exerienced during surgery; none, minimal, moderate, difficult, and extremely difficult (surgery not ossible). Outcome measures were the number of comlications and adverse events arising erioeratively, ain scores (VAS), visual exerience during surgery and intraoerative conditions as judged by the surgeon. In addition, after comletion of the rocedure, atients were asked to what extent they were satisfied with the alied tye of, and would it be their choice in the future eye surgery if any. All atients were blinded to the tye of local they received, eye atch was alied for all the atients articiating in the study. Statistical analysis was done using SPSS 15 (SPSS Inc., Chicago IL, U.S.A.). Outcome measures were comared using unaired t test, Nominal data were analyzed using Chi square and Fisher s exact tests as aroriate. Data were resented as number of atients, ercentage, mean ± SD as indicated, <0.05 was considered statistically significant. Results We rosectively enrolled 98 atients in the study, who were randomized into grous: 49 in the STB. grou and 49 in the TA. grou there was no statistically significant difference between the grous in terms of age, sex, ASA (American Society of Anesthesiologists) state, axial length of the oerating eye or surgery duration (Table 1). One atient was excluded after failure of administrating the sub-tenon's block. Table (1): Patients' characteristics in the two grous under study. Age (y) 69± ± M/F 29/ 19 33/ ASA I/II/III 11/34/3 10/37/2 NS Duration of surgery 28±8.4 33± Axial length of the eye 23.2± ± Data were resented as mean ± SD or number of atients as aroriate. There were no statistical differences between the two study grous in the reoerative eye comlications as shown in (Table 2). Table (2): Preoerative eye comlications in the two grous under study. Preoerative comlications Posterior synechia High myoia Axial length >26 High hyeroia Axial length <21 Uveitis Poor uillary dilatation Previous surgery Pars lana vitrectomy, membrane eeling (PPV, MP) Glaucoma surgery Periheral iridectomy Data were resented as number of atient. We found a mean 3mmHg ±.21 ost-anesthetic rise in intraocular ressure in the STB grou, and no rise in the TA grou (Table 3).

4 240 Sub-Tenon s Block Versus Anesthesia Table (3): Anesthesia related events in the two grous under study. VAS (cm) Absolute akinesia (16) 33% (0) 0% <0.001 Limited globe movement (32) 67% (0) 0% <0.001 Rise of intraocular ressure 3±0.21 0±00 <0.001 Data were resented as number of atients and ercentage or mean±sd as aroriate. Forty five (92%) of atients who received toical and 4ts (8%) of atients who received sub-tenon's reorted no ain during delivery of the anesthetic agents, the mean ain score was 0.44±0.32 in the toical grou and 2.12±0.52 in the sub-tenon grou. The difference between grous was statistically significant < One case had been excluded from the study after difficulty in delivering the anesthetic agents to the sub-tenon's sace accomanied with sever ain that we had to sedate the atients. Thirty two atients (65%) of atients in the toical grou and 45 atients 94% in the sub-tenon's grou reorted no ain or minimal discomfort during surgery (mean score 2.17 ± 1.89, 0.38± 1.11 resectively < forty three atients (88%) of toical atients and 48 atients (100%) of sub-tenon's atients reorted no ain or minimal discomfort immediately ostoeratively (mean score 1.80 ±0.73, 0.13 ±0.24, resectively) <0.001 twenty four atients (49%) of the toical grou and 48 atients (100%) of the sub-tenon's grou reorted no ain 3 hours ostoeratively (mean ain 0.45 ±0.27, 0 resectively) <0.001 (Fig. 1). STA TA 1 st 2nd 3 rd 4th Data Were resented as mean±sd. 1 st = VAS during delivery. 2nd = VAS during surgery. 3rd = VAS immediately ostoerative. 4th = VAS 3hrs ostoeratively. Fig. (1): Visual analog score for ain (VAS). Anesthesia related comlications including rolonged akinesia of the globe, sub-conjunctival hemorrhage and conjunctival swelling occurred significantly more frequently in the sub-tenon's than in the toical grou, sulemental eye analgesia during surgery was indicated in 5 cases subjected to toical (Table 4). Table (4): Anesthesia related comlications in the two grous under study. Conjunctival hemorrhage Conjunctival swelling (chemosis) Prolonged akinesia of the globe Sulemental (24) 50% (0) 0% <0.001 (19) 40% (0) 0% <0.001 (5) 10% (0) 0% (0) 0% (5) 10% Data were resented as number of atients, ercentage. Seventy five ercent of the sub-tenon grou (36 atients) and 96% (46 atients) in the TA grou exerienced visual awareness. On questioning, the majority 91.5% (75 atients out of 82 atients) found the visual exerience accetable, only 8.5% (7 atients out of 82 atients) felt it unleasant, two atients in the sub-tenon grou and five atients in the toical grou which was statistically nonsignificant =0.436 (Table 5). Patients exerienced a wide variety of visual sensations during surgery under sub-tenon's as well as toical anaesthesia. aears to result in more visual awareness than sub-tenon's. Seven atients found their visual exerience during surgery unleasant. Table (5): Visual exerience during surgery in the two grous under study. No light ercetion (12) 25% (3) 4% Visual awareness (36) 75% (46) 96% Unleasant visual awareness exerience (2) 2.4% (5) 6.1% Data were resented as number of atients and ercentage. There were no statistical differences between the 2 study grous in the intraoerative surgical comlications as shown in (Table 6).

5 Ghada A. El-Awady & Sherif R. Gohar 241 Table (6): Intraoerative surgical comlications in the two grous under study. Casular tear Vitreous loss Iris rolase Anterior chamber IOL 0 0 NS Zonular tear Data were resented as number of atients. Sub-tenon's infiltration was found satisfactory by 46atients 96% of atients and they would choose the same for another rocedure. The only comlaint was a moderate discomfort during injection in some cases, 32 atients 65% of atients subjected to toical were satisfied with the whole rocedure < Surgical conditions were graded to be otimal by the surgeon (none-minimal difficulties) in 46 atients (96%) subjected to sub-tenon's block and in 32 atients (65%) subjected to toical <0.001 (Table 7). Table (7): Anesthesia-related intraoerative difficulties as judged by the surgeon in the two grous under study. None <0.001 Minimal 5 18 =0.004 Moderate 2 11 =0.015 Difficult 0 6 =0.027 Extremely difficult 0 0 NS Data were resented as number of atients. Discussion has become increasingly oular, as indicated by the annual survey of the ractice styles and references of members of the American Society of Cataract and Refractive Surgery however, its use varied with the volume of surgery, increasing by 22% for surgeons doing 0 to 5 cataract rocedures er month and by 63% for those doing more than 51 [12]. On the other hand, toical can in certain circumstances be more demanding for the surgeon and seems to be articularly difficult in atients requiring more intraocular maniulation than usual, as in those with small uils or any other risk factors. This study showed that comlicated cataract surgery can be erformed under toical without comromising the safety of the rocedure. While surgery-related comlications under toical were similar to those occurring when subtenon's block was used. Anesthesiarelated comlications were seen exclusively in the sub-tenon's grou. Although our results of ain assessment during delivery favored the toical technique, atient assessments of ain during surgery, immediately and 3h ostoeratively were statistically significant favoring the sub-tenon's block. More -related difficulties encountered by the surgeons during cataract surgery in the toical grou led us to conclude that difficult cases of cataract surgery is more demanding for the surgeon using toical. "Globe akinesia is commonly not achieved with toical, making cataract surgery in demanding cases ossibly even more difficult for the surgeon. As exected, overall surgical conditions assessed by the surgeon favored the use of sub-tenon's block. The intergrou difference in surgeon's assessment was statistically significant. These results is similar to the findings of a study [13] comaring toical with sub-tenon's, but contradict the results of Uusitalo et al, [14] who found araocular injection significantly less difficult, surgeon's evaluation of the technique has been favorable as demonstrated by the fact that atients' cooeration was good in majority of cases (87.5%). In most of the atients, there were no unwanted eye movements (83%). With toical, there is no rise in intraocular ressure as comared with eribulbar. This is because the lacement of 5 ml of anesthetic cocktail in the orbit increases the intraocular ressure. Thus, even without the use of ocular ressure, the anterior chamber stability is good in toical. Thus, combining toical with intracameral 0.5% lignocaine makes cataract management better in every resect. This study however has its own limitations. Being a noncomarative study, conclusive evidence of sueriority of toical over local for cataract surgery is not available. A revious study concluded that Patients having cataract surgery under toical had more intraoerative and ostoerative discomfort than atients receiving sub-tenon's. However, atients having toical reorted less

6 242 Sub-Tenon s Block Versus Anesthesia ain during its administration and had fewer comlications. They concluded that both methods rovided high levels of ain control without additional sedation [15]. The surgeon in the current study observed that some atients under toical had inadvertent eye movements during surgery. The surgeon found minimizing eye movements during casulorhexis is crucial secially in such comlicated cases. Ninety six ercent of atients exerienced a wide variety of visual sensations during surgery under toical anaesthesia. Patients comrised oerating microscoe light, colours, vague movements, surgical instruments or surgeon hands, during surgery, change in colours during surgery and some visual alteration during corneal irrigation. anaesthesia aears to result in greater visual awareness than subtenon, 96% and 75% of the study atients under both anesthetic techniques resectively however; the majority of the atients 91.5% did not fined their visual exerience during surgery unleasant, though the oerating lights were uncomfortable for 7 atients. Fichman has investigated the blood ressure, ulse rate, and resiration rate of atients during surgery under toical and has found no major changes in these arameters [16]. There is no significant change in the lasma cortisol levels during surgery under toical, indicating that the rocedure is well tolerated and does not ose stress to the atient [17]. Thus, with all the advantages of toical, it may be the referred technique [18-20]. The clear corneal aroach for MSICS has the roblem that an attemt to kee the incision size small, so that it is selfsealing will cause stretching of the wound during delivery of the nucleus and will cause ain leading to unaccetability by atients [21]. Therefore in some studies they have used 2% lignocaine gel in lace of dros, as the gel formulation is suerior in roviding [22,23]. has additional benefits like not interfering with visual function, immediate visual recovery, absence of ain due to injection, unlimited ocular motility, and absence of an increase in orbital volume [24]. Various studies regarding the ain ercetion and atients' accetability for anesthetic technique have been done and they concluded that the atients' satisfaction for is comarable for toical versus other techniques [18-21]. We believe that toical is justified to imrove the safety and comfort of the atient in ordinary cases of cataract surgery and is likely to become the referred tye of in small-incision hacoemulsification and foldable IOL imlantation, articularly for socalled high-volume surgeons. Conclusion: Patients with comlicated cataract surgery under toical had more intraoerative and ostoerative discomfort than atients receiving sub-tenon's. However, atients having toical reorted less ain during its administration and had fewer related comlications. Sub-tenon's was suerior to toical in the management of comlicated cataract cases. References 1- LEARNING D.V.: Practice styles and references of ASCRS members survey. J. Cataract Refract Surg., 17: , FICHMAN R.A.: Use of toical alone in cataract surgery. J. Cataract Refract Surg., 22: , PATEL E.A., CARLSON T.A., CRANDALL A., et al.: A comarison of toical versus retrobulbar for cataract surgery. Ohthalmology, 103: , ZEHETMAYER M., RADAX U., SKORPIK C., et al.: versus retrobulbar in clear corneal cataract surgery. J. Cataract Refract Surg., 22: , KOCH P.S.: Efficacy of lidocaine 2% jelly as a toical agent in cataract surgery. J. Cataract Refract Surg., 25: , TSENG S.H. and CHEN F.K.: A randomized clinical trial of combined toical-intracameral in cataract surgery. Ohthalmology, 105: , MACLEAN H., BURTON T. and MURRAY A.: Patient discomfort during cataract surgery with modified toical and eribulbar. J. Cataract Refract Surg., 23: , DAVIS D.B. and MANDEL M.R.: Anesthesia for cataract extraction. Int. Ohthalmol. Clin., 34: 13-30, GILLS J.P., CHERICHIO M. and RAANAN M.G.: Unreserved lidocaine to control discomfort during cataract surgery using toical. J. Cataract Refract Surg., 23: , KOCH P.S.: Anterior chamber irrigation with unreserved lidocaine 1% for during cataract surgery. J. Cataract Refract Surg., 23: , FUKASAKU H. and MARRON J.A.: Pinoint : a new aroach to local ocular. J. Cataract Refract Surg., 20: , LEAMING D.V.: Practice styles and references of ASCRS members: 1998 survey. J. Cataract Refract Surg., 25: , RODRIGUES P.A., VALE P.J., CRUZ L.M., CARVALHO R.P., RIBEIRO I.M. and MARTINS J.L.: versus sub-tenon block for cataract surgery: Surgical

7 Ghada A. El-Awady & Sherif R. Gohar 243 conditions and atient satisfaction. Eur. J. Ohthalmol. May-Jun., 18 (3): , UUSITALO R.J., MAUNUKSELA E.L., PALOHEIMO M., et al.: Converting to toical in cataract surgery. J. Cataract Refract Surg., 25: , ZAFIRAKIS PANAYOTIS, VOUDOURI ADAMANTIA, et al.: versus sub-tenon's without sedation in cataract surgery Journal of cataract and refractive surgery, vol. 27, , FICHMAN R.A.: Use of toical alone in cataract surgery. J. Cataract Refract Surg., 22: 612-4, GOZUM N., ALTAN-YAYCIOGLU R., GUCUKOGLU A. and ARSLAN O.: Does toical increase atient's serum cortisol level? Int. J. Ohthalmol. Visual Sci., 2: 2, NIELSEN P.J.: A rosective evaluation of anxiety and ain with toical or retrobulbar for small incision cataract surgery. Eur. J. Imlant Ref. Surg., 7: 6-10, MACLEAN H., BURTON T. and MURRAY A.: Patient comfort during cataract surgery with modified toical and eribulbar. J. Cataract Refract Surg., 23: , ZEHETMAYER M., RADAX U., SKORPIK C., MENA- PACE R., SCHEMPER M., WEGHAUPT H., et al.: versus eribulbar in clear corneal cataract surgery. J. Cataract Refract Surg., 22: 480-4, JOHNSTON R.L., WHITEFIELD L.A., GIRALT J., HARRUN S., AKERELE T., BRYAN S.J., et al.: versus eribulbar, without sedation, for clear corneal hacoemulsification. J. Cataract Refract Surg., 24: , BAREQUET I.S., SORIANO E.S., GREEN W.R. and O'BRIEN T.P.: Provision of anaesthesia with single alication of lidocaine 2% gel. J. Cataract Refract Surg., 25: , ASSIA E.I., PRAS E., YEHEZKEL M., ROTENSTREICH Y. and JAGER-ROSHU S.: using lidocaine gel for cataract surgery. J. Cataract Refract Surg., 25: 635-9, NIELSEN P.J.: Immediate visual caability after cataract surgery: versus retrobulbar. J. Cataract Refract Surg., 21: 302-4, 1995.