Evaluation of Anxiolysis and Pain Associated with Combined Peri- and Retrobulbar Eye Block for Cataract Surgery

Original Contribution Evaluation of Anxiolysis and Pain Associated with Combined Peri- and Retrobulbar Eye Block for Cataract Surgery Andre´ P. Boezaart, MD* Roland A. Berry, MD,† Julia J. Laubscher, RN,‡ Mercia L. Nell, RN‡ Department of Anesthesiology, University of Stellenbosch, Tygerberg, Cape Town, Western Cape, South Africa; and Medi-Clinic Hospital, Paarl, Western Cape, South Africa.

*Senior Consultant, Department of Anesthesiology, University of Stellenbosch †Ophthalmologist ‡Registered Nurse, Medi-Clinic Hospital Address correspondence to Dr. Boezaart at the Medi-Clinic Hospital, P.O. Box 6023, 7622 Paarl, South Africa. Received for publication August 27, 1997; revised manuscript accepted for publication December 22, 1997.

Study Objectives: To evaluate five different preoperative anxiolytic regimens in cataract surgery performed under regional anesthesia; to quantify the pain associated with combined peri- and retrobulbar injection (PRBI) of local anesthetic drugs; and to describe a technique of painless eye block. Design: Randomized, double blind, placebo-controlled study. Setting: Private clinic. Patients: 376 ASA I and II patients presenting for cataract surgery. Interventions: Patients were extensively briefed by the nursing staff on the various procedures. Of the 376 study patients, 136 preferred to have no anxiolytic drug. The remaining 240 patients were randomly allocated to one of six groups to receive either 3 mg of bromazepam, 6 mg of bromazepam, 0.5 mg of alprazolam, 1 mg of alprazolam, 5 mg of diazepam, or a placebo on a double-blind protocol. All patients received a standard combined peri- and retrobulbar eye block (PRBB) before surgery. Measurements and Main Results: Anxiety at various stages of the procedure and PRBB were measured on visual analog scale (0 –10). PRBB pain was compared with pain of intravenous (IV) cannula placement. On admission, anxiety of the 136 patients who preferred no anxiolytic premedication was significantly less than that of the 240 patients assigned to one of the six treatment groups (p ,0.05). There was no difference between the six treatment groups in reported anxiety before surgery (p .0.05) except for Group 1 (3 mg bromazepam), where anxiety increased before and during PRBB administration (p ,0.05). In all six treatment groups, anxiety decreased significantly 30 minutes after medication was administered (p ,0.05). For the total group, 61.18% of patients reported more or equal pain associated with the placement of the 20-gauge IV cannula than by the PRBB. Of the patients who received medication, 94% stated that, should they require another eye operation, they would like the same anxiolytic treatment. No patient requested general anesthesia for their next operation or to be rendered unconscious for PRBB. Conclusions: 1. There was interpersonal variation in the level of preoperative anxiety. 2. In patients who were anxious, the anxiolytic drugs and placebo decreased

Journal of Clinical Anesthesia 10:204 –210, 1998 © 1998 Elsevier Science Inc. All rights reserved. 655 Avenue of the Americas, New York, NY 10010

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Peri-retrobulbar Block Pain and Anxiolysis: Boezaart et al.

anxiety although the level of anxiety did not differ between the anxiolytic drugs or between placebo and the anxiolytic drugs. The only difference was in Group 1 patients (3 mg promazepam), who reported slightly increased anxiety before and during PRBB administration (p ,0.05). 3. Placement of the PRBB is less painful than the insertion of a 20 g IV cannula. © 1998 by Elsevier Science Inc. Keywords: Analgesia: eye surgery; anesthesia, regional: peribulbar block, retrobulbar block; anxiolysis; cataract surgery: analgesia; pain: ophthalmalogic surgery.

Introduction There is disagreement about the need for sedative or anxiolytic drugs to be given before peribulbar or retrobulbar injection of local anesthetic drugs in patients undergoing cataract surgery.1 In some centers, it is customary to administer sedative doses of various intravenous (IV) anesthetic drugs before retrobulbar injection.2 However, this practice has been criticized, particularly when used in elderly patients.3 Campbell et al.4 suggested a close correlation between pain and anxiety. Because retrobulbar injection with a 21-gauge or 23-gauge Atkinson needle is painful and uncomfortable,2 sedation with short-acting IV anesthetic drugs before retrobulbar injection has been advocated.2 The goals of this study were (1) to evaluate the value of premedication with different anxiolytic drugs in reducing anxiety in patients undergoing cataract surgery with local anesthesia and (2) to quantify the pain associated with PRBB by comparing it with the relatively familiar pain associated with the placement of an IV cannula. A technique of painless PRBB is described, and the rationale for this technique is discussed.

Materials and Methods The protocol was approved by the Medi-Clinic Hospital Institutional Ethical Committee. All patients provided written informed consent. A total of 376 adult ASA I and II patients presenting for cataract surgery with regional anesthesia were studied. On admission to the hospital, patients were extensively briefed by the nursing staff on the various procedures and asked if they required an anxiolytic drug; 240 patients (63.8%) requested anxiolytic therapy. These patients were then randomly allocated by card draw to one of six groups. The patients in each group received one of six oral drugs, code numbered by the hospital pharmacist so that neither patients, ward staff, anesthesiologist, nor surgeon knew which drug was used. Patients in Group 1 received 3 mg bromazepam; Group 2 received 6 mg bromazepam; Group 3 received 0.5 mg alprazolam; and Group 4, 1 mg alprazolam. Group 5 received 5 mg diazepam, and Group 6 received a multivitamin tablet as placebo. The medication was administered orally 60 to 90 minutes prior to administration of the eye block. The procedures were carefully explained in stages: the

consulting room staff explained the procedure up to admission to the hospital, while the ward staff discussed procedures up to the point before the eye block was done. An anesthetic nurse explained the block and the intraoperative procedure up to and including the recovery area. The ward staff then explained the procedures to be followed until the follow-up visit by the surgeon on the morning after the operation. Finally, the consulting room staff instructed the patients about postoperative care. Dentures and hearing aids were not removed before the operation,5 and patients were transferred fully clothed to a room adjoining the operating room (OR), where they were assisted to lie down on an examination couch. Monitoring, which consisted of ECG, noninvasive automated blood pressure (BP) measurements, and oxygen saturation (SaO2), was applied prior to administration of the eye block.

Technique of PRBB Peri-retrobulbar block (PRBB) block has been described previously1,6 and has been modified and adjusted by the current authors to provide painless and safe local anesthesia for ocular surgery. After disinfecting the periorbital skin, skin wheals were raised inferolaterally and superomedially from the eye, just above the inferior orbital rim, approximately 1.5 cm medial to the lateral canthus, and 1 to 2 mm medial and inferior to the superior orbital notch, using an intradermal injection of lidocaine 1% solution in Balanced Salt Solutiont (BSSt; Alcon, Fort Worth, TX, USA). A 12.5 mm, 29-gauge needle was used for this procedure. A 20-gauge IV cannula (Jelcot; Criticon, Sunninghill, UK) was then inserted under the same lidocaine/ balanced salt solution-local anesthetic mixture, injected with the same 29-gauge needle on the dorsum of the hand of each patient. Then 1.5 ml of a mixture of 5 ml bupivacaine (0.5%) and 1 ml lidocaine (10%) was injected transcutaneously into the inferolateral peribulbar space and 1.5 ml of the same mixture into the superomedial peribulbar space through the same 29-gauge needle. The needle was directed away from the eye in both instances, thus nullifying the possibility of global perforation. When diluted in this way, the 6 ml local anesthetic mixture consisted of 0.41% bupivacaine and 1.66% lidocaine. The peribulbar local anesthetic injection was given a few minutes to take effect, while light manual pressure was applied to the eye. A 35 mm, sharp, long-bevelled 21gauge needle was then placed transcutaneously via the inferolateral route into the intraconal retrobulbar space and a minute amount of local anesthetic mixture was injected as a test dose to confirm extraocular placement of the needle. Aspiration confirmed extravascular placement before approximately 3 ml of the same bupivacainelidocaine mixture was injected slowly into the intraconal space. Continuous manual palpation of the eyeball was done during the injection to evaluate intraocular pressure (IOP). If the pressure changed, the injection was terminated, because that was regarded as an indication that the retrobulbar space was filled to capacity with local anesthetic mixture. After the retrobulbar injection, external J. Clin. Anesth., vol. 10, May 1998

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pressure of approximately 30 mmHg was applied to the eye with a pressure reducing device (ORE Softballt; ORE Products, Paarl, South Africa). The lidocaine-balanced salt solution has a relatively neutral pH and raising a skin wheal by injecting this mixture with a 29-gauge needle intradermally and subcutaneously is painless when done carefully. It provides excellent anesthesia to the skin in the injected areas. The PRBB was designed such that the ‘‘path’’ of the thicker retrobulbar needle is fully anesthetized by the relatively small amount of peribulbar anesthetic without removing the warning sign of possible optic nerve damage or intraocular injection (pain). The relatively small amount of local anesthetic injected into the peribulbar space should only have effect on the outside of the muscle cone after such a short period. A sharp, long-bevelled needle was used to facilitate easy penetration of the muscle cone without pulling on the muscles and increasing IOP, which may be painful or may provoke the oculocardiac reflex. The only injection that carries the possible risk of global penetration would be the retrobulbar injection. In the design of the PRBB, the current authors argue that because the patients were fully conscious and the eye was at that stage not anesthetized at all, penetration of the globe will be highly unlikely. However, injection of the very small test dose of local anesthetic into the eye would cause a rise in IOP and subsequent pain of which the patient would complain. Arguably, this small increase in IOP would not cause damage to the eye due to barotrauma, which would be expected if large volumes were to be injected intraocularly. The mixture of 1.6% lidocaine and 0.41% bupivacaine was chosen because the lidocaine would hasten the onset of the block and the bupivacaine would lengthen the duration of the block. Both these properties could be achieved without increasing the volume of the injectate and, therefore, possibly increasing IOP. When complete akinesia and analgesia of the eye had been achieved, patients were transferred to the OR, where they were placed on a Bean Bagt (Orthoprax; Cape Town, South Africa) on the operating table. Earphones were put on and soothing music was played continually for the patients.7–10 Intraoperative monitoring included ECG, automated BP, pulse oximetry, and measurement of expiratory carbon dioxide (CO2), via modified nasal prongs.11 Oxygen was administered by the same modified nasal prongs. Surgery performed on all patients involved phacoemulsification lens extraction and intraocular lens implantation. On arrival back in the ward, patients were served refreshments and a questionnaire was completed by an unbiased observer who was not a member of the surgical team. Patients were asked to report their anxiety at the time of admission and 30 minutes after the anxiolytic drug was administered, before administration of the PRBB, during the administration of the eye block, before transfer to the OR, in the OR, during surgery, and after surgery. A visual analogue scale (VAS) (0 –10) was used to estimate anxiety.12–15 The patients were also asked if the music had 206

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contributed towards alleviation of anxiety. The fact that some of the patients received oral benzodiazepines was taken into account, and the possible anterograde amnesia sometimes caused by the drugs was acknowledged. If any patient failed to remember any of the events, this would be noted and the patient would be eliminated from the study. Patients were also asked to report on their experience of the pain associated with the PRBB on a VAS (0 –10) and to compare this pain with the pain associated with the placement of the IV cannula. Finally, those patients who requested and received oral anxiolytic drugs or placebo were asked whether they would prefer the same treatment, a more potent anxiolytic drug, a less potent anxiolytic drug, or no anxiolytic drug at all, or whether they would prefer not to be awake if they were required to undergo another PRBB block and similar eye operation. VAS measurements of anxiety and pain were compared within each group and among the six treatment groups. These measurements also were compared with those of the group of patients who did not request an anxiolytic drug. Data analyses were performed on the means and variance of the groups. Differences between groups were defined using analysis of variance (ANOVA). The validity of the conclusions about significance of difference of groups was confirmed by performing the Kruskal-Wallis nonparametric test, which is a rank version of the one-way ANOVA. A p-value of less than 0.05 was accepted as indicative of a statistically significant difference.

Results The mean age of the study patients was 67.2 6 12.5 years. There was no difference in the ages of the treatment groups (p .0.05). None of the patients were excluded from the study due to amnesia that could possibly have been caused by the benzodiazepine drugs, and oculocardiac reflex was not triggered in any of the patients. VAS values for anxiety at different stages of the procedure are summarized in Table 1. In the six treatment groups (including the placebo group), anxiety decreased significantly 30 minutes after the test drug was administered (p ,0.05). There was no difference seen among the six groups (p .0.05). Anxiety levels, when compared with the anxiety levels 30 minutes after the administration of the test drug, increased just before and during the PRBB in Group 1 patients (3 m bromazepam) (p ,0.05). During all the other stages, anxiety levels remained similar to anxiety levels 30 minutes after taking the test drug in the above-mentioned group (p .0.05). In the other five groups, including the placebo group, anxiety levels did not change from the anxiety levels 30 minutes after the test drug was taken (p .0.05). The group that received no anxiolytic medication had anxiety levels similar to those of the treatment groups (p .0.05). After the PRBB was administered, anxiety remained constantly low during and after surgery in patients in all seven groups. On admission, the anxiety levels of the patients who did not request anxiolytic therapy was significantly less than that of patients who did so (p ,0.05). At all the other

Table 1. Anxiety As Measured By Visual Analogue Scale in the Study Groups Group 1

Drug

Bromazepam 3 mg

Group 2

Bromazepam 6 mg

Group 3

Alprazolam 0.5 mg

Group 4

Alprazolam 1 mg

Group 5

Diazepam 5 mg

Group 6

Placebo

Anxiety on admission 2.95 6 1.57 3.45 6 2.56 3.85 6 2.87 3.05 6 2.04 3.15 6 2.13 2.85 6 1.39 1.85 6 1.69† 1.75 6 2.17† 1.25 6 2.04† 1.05 6 1.27† 1.20 6 1.24 Anxiety 30 minutes after drug 1.10 6 1.37† 1.60 6 2.03† 1.25 6 1.55† 1.15 6 1.49† 1.70 6 1.52† 1.00 6 1.33† Anxiety in OSBA prior to PRBI 2.1 6 1.78‡ 1.50 6 1.90† 1.50 6 1.56† 1.00 6 1.41† 1.55 6 1.50† 1.65 6 1.49† Anxiety in OSBA during PRBI 2.95 6 2.43‡ † 1.20 6 1.57† 1.20 6 1.43 0.80 6 1.47† 0.75 6 1.02† 0.95 6 1.43† Anxiety in OSBA after PRBI 0.70 6 1.12 prior to surgery Anxiety in OR during surgery 1.10 6 1.917† 0.95 6 1.27† 0.85 6 1.26† 0.70 6 1.12† 1.30 6 1.59† 0.65 6 1.26 0.26 6 0.56† 0.30 6 0.73† 0.30 6 0.57† 0.30 6 0.57† 0.15 6 0.48† Anxiety after surgery 0.10 6 0.30† Age 66.2 6 10.56 68.9 6 15.22 66.7 6 12.34 65.3 6 13.59 66.4 6 13.59 66.4 6 11.86 n 40 40 40 40 40 40

P-Value

Group 7

P-Value

Groups 1 through 6

No treatment

Group 7 vs. Groups 1 through 6

0.988 0.423 0.037 0.022 0.878

0.55 6 1.41* N/A 1.20 6 2.16†,§ 1.20 6 2.03†,§ 0.92 6 1.34†

0.001 N/A 0.187 0.023 0.908

0.797 0.740 0.001

0.848 0.349 0.001

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OSBA 5 operating suite block area, OR 5 operating room, PRBI 5 periretrobulbar injection, N/A 5 not applicable, n 5 number of patients per group. * Significantly less anxiety in Group 7 when compared with anxiety in the other six groups (p ,0.05). † Significantly less anxiety in each group when compared with anxiety on admission (p ,0.05). ‡ Significantly higher anxiety in Group 1 when compared with other groups (p ,0.05). § Significantly more anxiety in Group 7 when compared with anxiety on admission in Group 7 (p ,0.05).

1.11 6 1.95† 0.40 6 0.84† 68.1 6 12.46 136

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136 40

0.20 6 0.52

0.255(NS)

0.53 6 1.10

0.410 (NS) 0.342 (NS) 1.82 6 1.61 0.862(NS) 1.95 6 1.19

2.35 6 1.81 0.65 6 1.04 40 2.05 6 1.93 0.15 6 0.48 40 NS 5 nonsignificant difference.

40

0.45 6 0.82 0.20 6 0.52 Pain with surgery

40

2.05 6 2.25 2.52 6 2.17 Pain with PRBI

Patient n

Bromazepam 6 mg Bromazepam 3 mg Drug

1.95 6 1.93 0.15 6 0.48 40

Alprazolam 1 mg

Diazepam 5 mg

Placebo

Groups 1 through 6

No treatment

Group 7 vs. Groups 1 through 6 Alprazolam 0.5 mg

Group 7 P-Value Group 6 Group 5 Group 4 Group 3 Group 2

Anxiety and pain are subjective experiences and, as such, they are difficult to measure. By making use of the patient’s own perception, graded on a VAS, we could obtain anxiety and pain measurements to address the questions posed in this study. The VAS is a well accepted method of quantifying subjective perceptions for study purposes.12–15 A further consideration in the design of the study was the fact that benzodiazepines might have had an anterograde amnesic effect on some of the patients that could render inaccurate measurements of what the patients recalled from the procedure. Because pain and anxiety are subjective experiences, the current authors argued that it was in fact precisely the patients’ interpretation of these perceptions that was the subject of this study. Whether the patients experienced anxiety and pain on a subjective level was the important question asked by this study. None of the patients reported amnesia that could have been caused by one of the drugs, and this theoretical possibility was not encountered. It was, there-

Group 1

Discussion

Table 2. Pain Associated With Periretrobulbar Injection (PRBI) and Surgery as Measured by Visual Analogue Scale in The Different Study Groups

stages, however, anxiety levels between this group and the other groups did not differ significantly (p .0.05). Music reportedly helped to reduce the level of anxiety in 85% of the patients, while 15% stated that the music made no difference. The reported pain levels associated with PRBB and surgery are summarized in Table 2. When asked to compare the pain caused by the PRBB to that associated with the IV cannula insertion, 34 patients (8.95%) stated that the eye block was as painful as the placement of the IV cannula, 166 (44.02%) reported that it was less painful, 30 (8.21%) reported that it was much less painful, and 116 (30.60%) stated that the eye block was more painful than the placement of the IV cannula. Thirty patients (8.21%) reported much more pain with the PRBB (Table 3). The VAS for pain associated with the eye block for all the patients grouped together was 2.2 6 1.93, and it did not differ among groups (p .0.05). Prior treatment with anxiolytic drugs did not have any influence on pain associated with PRBB in this study. When patients were asked whether they would prefer anything to be done differently from the current procedure if they required an additional eye operation for cataract removal, 354 (94.15%) said that they would prefer everything to be done in the same way, 20 (5.32%) indicated that they would like a more potent anxiolytic drug, and 2 patients (0.53%) would prefer a less potent anxiolytic drug. None of the patients said that they would prefer the operation to be done with general anesthesia or to have the PRBB while not conscious. The only complication observed in the present study was periorbital ecchymosis in 20 patients (5.3%). None of the patients in this study experienced oversedation or amnesia, nor did any become confused or move excessively during placement of the PRBB or during surgery. No retrobulbar haemorrhages were observed in any of the patients studied.

P-Value

Original Contributions

Peri-retrobulbar Block Pain and Anxiolysis: Boezaart et al.

Table 3. Pain Associated with PRBI Compared with the Pain Associated with Intravenous Cannula Placement

PRBI much less painful PRBI less painful PRBI as painful PRBI more painful PRBI much more painful Total

Number of patients

%

30 166 34 116 30 376

8.21 44.02 8.95 30.60 8.21 100

fore, possible to gather meaningful data from the patient population studied. There is no doubt that placement of a conventional retrobulbar block using a 21-gauge or 23-gauge Atkinson needle is a painful procedure and the majority of patients would demand some type of sedation.2 The patient population evaluated in the current study consisted of private patients who reside in a relatively small community, where word-of-mouth is an important method of communication. It is therefore possible that the patients communicated to each other the absence of pain and the friendly atmosphere in which the procedure was done, and, by doing so, to a large extent created and strengthened the perception that there was nothing to fear from the procedure. However, this may not be the case in other communities and larger cities where the opposite perceptions may be created and spread. In our opinion, this is precisely the reason why major emphasis should be placed on doing the eye block in an absolutely pain-free manner. We feel that the block described in this communication, if done carefully, achieves this goal, as our data conclusively support. A relatively large number of patients (136 of 376, or 36%) did not experience sufficient anxiety on admission to deem it necessary to request anxiolytic therapy. The relatively small community and word-of-mouth situation, as discussed above, may also, to some extent, account for this finding. The VAS score confirmed the lower level of anxiety in this group of patients (Group 7). It can be concluded that, in this patient population, routine use of sedation before eye surgery with regional anesthesia probably was not indicated. The clinician can probably be guided by the patient’s preference regarding anxiolytic treatment. Careful stepwise explanation of the procedure to the patients seemed to contribute significantly to alleviating anxiety. However, we could not distinguish between the therapeutic value of this practice and the effects of the drugs. Comparisons to those patients who did not request drugs were invalid as they represent a biased specific group of personalities probably not comparable to the rest of the study population. In the present study, no differences in anxiety levels were observed between patients treated with anxiolytic drugs and those who were given a placebo. These findings suggest that anxiolytic therapy is probably of no discernible benefit in reducing the anxiety associated with cataract surgery with local anesthesia. The results further indicate that anxiety increased immediately before and during the eye block in

the group of patients who received 3 mg bromazepam. This increase in anxiety could not be demonstrated for any of the other groups, including the placebo group and the group that received no medication. This finding is difficult to explain. Larger numbers of patients in the different groups probably would have given more clarity to this situation. According to the findings, this drug should either not be used at all or should be used in higher dosages, as indicated by the findings of Group 2 (6 mg bromazepam), where anxiety did not increase before or during the administration of the eye block (Table 1). The only time when the patients were anxious was the period around the eye block, and thus special attention should be given to patients during this period. Once the block had been administered, the patients were relaxed and did not seem to be anxious about the impending surgery. Factors such as the comfortable positioning on the operating table by means of a ‘‘Bean Bag’’ and playing soothing music to the patients probably also contributed to less discomfort and anxiety. The possible role played by the nursing staff in alleviating the anxiety of the patients also cannot be ignored. The fact that a study measuring anxiety was in progress could have prompted the nursing staff to be more than usually sympathetic to the patients and could have biased the results. However, other workers16 have found that nursing interventions play a significant role in the relief of preoperative anxiety. Anxiolytic therapy made no difference to the pain associated with PRBB. The overall level of pain, as measured by VAS, was generally low. Only a small percentage of patients reported the pain associated with the eye block to be worse than the pain caused by the placement of the IV cannula, while the majority (61.18%) stated the pain associated with PRBB was equal to or less than that associated with the placement of the IV cannula (Table 3). Because the pain associated with the placement of an IV cannula under local anesthesia is known to be relatively low, it can be concluded that the pain experienced with the eye block given in the present study also must have been low. This conclusion was confirmed by the overall mean pain score of 2.2 6 1.88 on VAS reported by the patients in our study. Therefore, we feel that the use of IV sedative and anesthetic drugs such as propofol, methohexital, or alfentanil are not indicated to alleviate pain associated with eye block in cataract surgery. These drugs may be indicated if more conventional and painful approaches to retrobulbar blocks are used. In addition, these drugs possibly could increase the dangers associated with retrobulbar injections because warning symptoms of incorrect needle placement, such as intrabulbar placement or placement into the dura mater-covered optic nerve, may be masked. Eye movements are also limited when patients are fully awake and cooperative, possibly decreasing the chance of retrobulbar hemorrhage.1 The low percentage of patients who stated that they would like a more potent drug to be used for their next eye operation (5.3% of the patients who received anxiolytic drugs or placebo) and the fact that none of the patients in the current study stated that they would prefer J. Clin. Anesth., vol. 10, May 1998

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general anesthesia or not to be conscious or awake during the eye block for their next eye operation, supports our contention. If IV drugs are used, only ultra-short acting drugs such as propofol should be used, and then only during the peribulbar part of the eye block. Because the retrobulbar part of the eye block, as described here, was consistently painless, we feel that it is not justified to subject the patient to additional dangers by removing important warning signs of needle misplacement, or possibly by causing excessive head movement by the patient, which otherwise might result when performing this part of the block without the patient’s full cooperation. We conclude that oral benzodiazepine anxiolytic drugs and IV or oral sedation, probably are not routinely indicated for cataract surgery performed with local anesthesia. Anxiety and pain may be sufficiently alleviated by careful stepwise explanation of the procedure, sympathetic nursing staff, carefully executed, painless local anesthetic injections, and comfortable positioning on the operating table. If anxiolytic premedication is required by the patient, then a dose of 3 mg bromazepam probably should be avoided and ultra-short acting drugs be used in sedative doses during the peribulbar part of this eye block. Soothing music also may contribute to patient comfort.

References 1. Boezaart AP, Boezaart LC, Berry R: Limiting movement during retrobulbar block [Letter]. Anesth Analg 1996;83:202–3. 2. Yee JB, Schafer PG, Crandall AS, Pace NL: Comparison of methohexital and alfentanil on movement during placement of retrobulbar nerve block. Anesth Analg 1994;79:320 –3. 3. Salmon JF, Mets B, James MF, Murray AD: Intravenous sedation

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4. 5.

6.

7.

8. 9. 10. 11.

12.

13. 14. 15.

16.

for ocular surgery under local anaesthesia. Br J Ophthalmol 1992;76:598 – 601. Campbell WI, Lewis S: Visual analogue measurement of pain. Ulster Med J 1990;59:149 –54. Cobley M, Dunne JA, Sanders LD: Stressful pre-operative preparation procedures. The routine removal of dentures during pre-operative preparation contributes to pre-operative distress. Anaesthesia 1991;46:1019 –22. Galindo A: Retro-peribulbar anesthesia, special technique and needle design. In: Gills JP, Hustead RF, Saunders DR (eds.): Ophthalmic Anesthesia. New York: SLACK Inc., 1993:125–7. Updike PA, Charles DM: Music Rx: physiological and emotional responses to taped music programs of preoperative patients awaiting plastic surgery. Ann Plast Surg 1987;19:29 –33. Kaempf G, Amodei ME: The effect of music on anxiety. A research study. AORN J 1989;50:112– 8. Cirina CL: Effects of sedative music on patient preoperative anxiety. Today’s OR Nurse 1994;16:15– 8. Evans MM, Rubio PA: Music: a diversionary therapy. Today’s OR Nurse 1994;16:17–22. Braz JR, Takata IH, Sato JK, Gorayb SB, Mo´dolo NS: Capnometry with nasal prong in patients under spontaneous ventilation. Braz J Anesthesiol Int 1996;7:1– 4. Vogelsang J: The Visual Analog Scale: an accurate and sensitive method for self-reporting preoperative anxiety. J Post Anesth Nurs 1988;3:235–9. Hicks JA, Jenkins JG: The measurement of preoperative anxiety. J R Soc Med 1988;81:517–9. Gaberson KB: The effect of humorous and musical distraction on preoperative anxiety. AORN J 1995;62:784 –91. Millar K, Jelicic M, Bonke B, Asbury AJ: Assessment of preoperative anxiety: comparison of measures in patients awaiting surgery for breast cancer. Br J Anaesth 1995;74:180 –3. Kapnoullas J: Nursing interventions for the relief of preoperative anxiety. Aust J Adv Nurs 1988;5:8 –15.