Brain stem anesthesia after retrobulbar block

Study of safety and efficacy of sub-Tenon and subconjunctival anesthesia in manual small-incision cataract surgery for hard-grade cataracts

PURPOSE

The purpose was to study the safety and efficacy of sub-Tenon and subconjunctival anesthesia in manual small-incision cataract surgery (MSICS) in patients with hard-grade cataracts.

STUDY DESIGN

The design of the study was a prospective, observational, and randomized control study.

MATERIALS AND METHODS

A total of 196 eyes, including 98 eyes in the subconjunctival anesthesia group (group A) and 98 eyes in the sub-Tenon anesthesia group (Group B), undergoing MSICS were enrolled in the study. A single surgeon performed all the surgeries. Intraoperative and postoperative pain scores, patient comfort, surgeon's satisfaction, and intraoperative complications were examined.

RESULTS

The mean age of patients in Group A was 66.64 ± 9.95 years and that of patients in Group B was 64.52 ± 9.46. No statistically significant difference was noted in the intraoperative (P = 0.54) and postoperative pain (P = 0.66) scores between the two groups. There was no pain (0 score) in 30% of patients in Group A and 35% of patients in Group B intraoperatively. The average surgical time (P = 0.66) and surgeon's comfort (P = 0.34) were not statistically significant. The mean corneal haze was 0.054 ± 0.12 in group A and 0.065 ± 0.22 in group B (P = 0.45). Two patients in group A required supplemental anesthesia. There were no surgical complications that could compromise visual outcomes. No patients in either group showed alterations in vital parameters or required intravenous sedation.

CONCLUSION

Both techniques of anesthesia are safe and effective for performing MSICS in hard-grade cataracts. However, it is prudent to choose a technique according to the surgeon's requirements.

Apnea caused by retrobulbar anesthesia: A case report

BACKGROUND

Apnea caused by retrobulbar anesthesia is a very rare but severe complication during ophthalmic surgery.

CASE SUMMARY

We report a rare case of apnea caused by retrobulbar anesthesia, and emergency resuscitation was used. A 74-year-old female patient was diagnosed with rhegmatogenous retinal detachment in the right eye and planned to undergo vitrectomy under retrobulbar anesthesia. After the retrobulbar anesthesia in her right eye, she became unconscious and apneic. It was suggested that she had developed brainstem anesthesia. Assisted ventilation was initiated. Atropine 0.5 mg, epinephrine 1 mg, ephedrine 30 mg, and lipid emulsion were given. Five minutes later, her consciousness and breathing gradually returned, but with uncertain light perception in her right eye. Alprostadil 20 µg was given, and after 2 h her visual acuity resumed to the preoperative level.

CONCLUSION

Brainstem anesthesia is a serious complication secondary to retrobulbar anesthesia. Medical staff should pay attention to the identification of brainstem anesthesia and be familiar with the emergency treatment for this complication.

A Case of Brainstem Anesthesia after Retrobulbar Block for Globe Rupture Repair

Purpose

To present a rare case of brainstem anesthesia from retrobulbar block and discuss evidence-based methods for reducing the incidence of this complication.

Case

A 72-year-old female, was given a retrobulbar block of 5 mL of bupivacaine 0.5% for postoperative pain management, after a globe rupture repair under general anesthesia. Prior to injection, the patient was breathing spontaneously via the anesthesia machine circuit and had not received any additional narcotics/muscle relaxants for 2.5 hr (with full recovery of neuromuscular blocking agent after anesthetic reversal). Over 7 min, however, there was a steady increase in ETCO₂ and the patient became apneic, consistent with brainstem anesthesia. She remained intubated and was transported to the postanesthesia care unit for prolonged monitoring, with eventual extubation. Discussion. Brainstem anesthesia is an important complication to recognize as it can lead to apnea and death. The judicious use of anesthetic volume, shorter needle tips, and mixed formulations can help reduce the chance of brainstem anesthesia. Observation of the contralateral eye 5–10 minutes after injection for pupillary dilation, and prior to surgical draping, can help identify early CNS involvement.

A New Two-Step Anesthesia for 23- or 25-Gauge Vitrectomy Surgery: A Prospective, Randomized Clinical Trial

OBJECTIVE

To investigate the safety and efficacy of topical anesthesia combined with subconjunctival anesthesia (termed two-step anesthesia) for 23- or 25-gauge pars plana vitrectomy or other posterior segment surgery.

METHODS

Patients (n = 90) requiring 23-/25-gauge vitrectomy or other posterior segment surgery were randomized into 3 groups. Group 1 received peribulbar anesthesia, group 2 received retrobulbar anesthesia and group 3 received two-step anesthesia. A 5-point visual analog pain scale (VAPS) was used to measure self-report of patient pain. Complications were recorded for subsequent analysis.

RESULTS

VAPS scores for overall intraoperative pain ranged from 0 to 3 (1.07 ± 1.07) in group 1, from 0 to 2 (0.69 ± 0.93) in group 2 and from 0 to 3 (1.06 ± 0.98) in group 3. Assessment of surgeon discomfort score ranged from 0 to 2 (0.31 ± 0.66) in group 1, from 0 to 3 (0.38 ± 0.82) in group 2 and from 0 to 2 (0.47 ± 0.62) in group 3. Both scores reveal no significant difference among the 3 groups. While there were no complications noted in group 1, there was an ocular perforation in group 2. Additionally, there were no complications in group 3 related to the anesthetic technique.

CONCLUSIONS

Results suggest that two-step anesthesia is a safe and effective anesthetic approach for selected patients undergoing 23- or 25-gauge pars plana vitrectomy or other posterior segment surgeries. It may offer a viable alternative to peribulbar anesthesia and retrobulbar anesthesia for carefully selected 23- or 25-gauge cannular-access ocular surgeries.

Brainstem Anaesthesia after Retrobulbar Block

Regional anaesthesia techniques in ophthalmology are usually utilized for day case surgery. During various procedures, profound akinesia of the eye and anaesthesia of the surgical site are required, both of which are achieved with retrobulbar block. Due to the anatomy of the eye, life-threatening complications are possible. An 82-year-old female with secondary post-herpetic uveitic glaucoma of the right eye presented at the Department of Ophthalmology for an elective trans-scleral laser cyclophotocoagulation. She was given a retrobulbar block to the right eye with 2 mL of 0.5% levobupivacaine and 2 mL of 2% lidocaine. The procedure was technically performed without any issues. 2-3 minutes after the injection she became lethargic and 5 minutes later she lost consciousness and developed severe hypotension with bradycardia and respiratory arrest. She was successfully intubated and resuscitated, using mechanical ventilation, vasoactive medications, fluid therapy and intravenous lipid emulsion. There are three mechanisms for local anaesthetic (LA) to reach the central nervous system after a retrobulbar block: systemic absorption of LA, direct intra-arterial injection and retrograde flow into the cerebral circulation, and injecting LA into the subdural space via puncturing the dural optic nerve sheath, the latter being most common. The clinical picture of our patient was very consistent with subdural anaesthesia after exposure of the pons, midbrain and cranial nerves to LA, i.e. brainstem anaesthesia. Following appropriate life support measures taken in our case, there was a successful outcome. To minimize the chance for brainstem anaesthesia after retrobulbar block, we recommend low volume with low concentration of LA and block performance by an experienced ophthalmologist or anaesthesiologist with proper technique. Patients receiving retrobulbar anaesthesia should be carefully monitored at least 20 minutes after the block. Life support equipment should be available before performing retrobulbar block.

Real-time ultrasound-guided retrobulbar block vs blind technique for cataract surgery (pilot study)

Background

Retrobulbar regional eye block aims to ensure eye globe akinesia and anesthesia during ophthalmic surgery, and despite the rarity of occurrence of complications due to the blind needle passage while performing either peribulbar or retrobulbar block, some of them are serious and may be life threatening.

Aim

The aim of this study was to estimate the accuracy and safety of real-time ultrasound-guided retrobulbar regional anesthesia in comparison with the blind technique for cataract surgery.

Design

This was a prospective randomized controlled trial.

Methodology

A total of 30 patients who met the inclusion criteria were registered in our research and were divided into two groups: 15 patients received real-time ultrasound-guided retrobulbar block compared to 15 patients who received the block using the blind technique.

Results

One patient out of the 30 was excluded from the analysis, and no statistically significant differences were observed between the two groups regarding the onset of akinesia, numeric pain rating scores, rate of complications, and degree of patient and physician satisfaction.

Conclusion

There were no statistically significant difference between real-time ultrasound-guided and blind retrobulbar regional eye blocks concerning the onset of action, total volume of injected local anesthetic solution, supplemental injection required, pain scores, and degree of patient satisfaction.

Orbital Depth Measurements of Human Skulls in Relation to Retrobulbar Anesthesia

To investigate the orbital depth in human skulls in relation to retrobulbar anesthesia, we measured the distance between the lateral margin of the optic foramen and the border of the medium and outer third of the inferior orbital rim (retrobulbar needle pathway) in 50 skulls (25 males and 25 females). This distance varied from 4.4 to 5.7 cm in males (mean 5.024, SD 0.272) and from 4.5 to 5.5 cm in females (mean 4.9, SD 0.204). There was no real difference between males and females (p>0.05).

For the total of 50 skulls the mean distance was 4.962 cm (SD 0.246).

Shallow and deep orbits exist in both males and females but individuals with shallow orbits are obviously more susceptible to optic nerve injury by the retrobulbar needle.

Cataract surgery in mobile eye surgical unit: Safe and viable alternative

Aim:

The aim of this study was to evaluate the utility and safety of a mobile eye surgical unit (MESU) in providing quality cataract surgery for the indigent rural population with poor access to quality eye care.

Materials and Methods:

Two buses connected by a vestibule were built to meet the requirements for a self-sufficient operation theater (OT). In every camp, safe transportation of units, good alignment of buses, safe water, and maintenance of sterile environment were achieved with optimal utilization of OT.

Results:

Two thousand and twenty-one patients in 21 remote locations underwent cataract surgery in MESU between 2012 and 2015. Visual outcome was 6/9 or better in 79.3%, posterior capsular rupture in 0.91%, zonulardialysis in 0.3%, aphakia in 0.2%, iridodialysis in 0.2%, and there was no incidence of endophthalmitis.

Conclusion:

MESU is a safe alternative in combating preventable blindness due to cataract in far-off villages and tribal areas by providing quality eye care at the patient's doorstep. This model has a great potential for duplication in other parts of India.

Brainstem Anesthesia after Retrobulbar Block: A Case Report and Review of Literature

Background

Retro-bulbar anesthesia is one of the most common regional blocks used for intraocular surgeries. Complications associated with regional blocks may be limited to the eye or may be systemic.

Case Report

After a retro-bulbar block for glaucoma surgery, a 60-year-old man developed loss of consciousness, apnea with hypotension and bradycardia-features of brainstem anesthesia. We present the clinical features, treatment and comments on how to prevent the problem as well as a review of the literature on reported cases.

Conclusion

Although it is rare, treating physicians should be aware of the potentially lethal consequences of retro-bulbar block, understand measures to reduce the risks and early recognition and treatment. Facilities where ophthalmic surgeries are performed under local anesthesia should be properly equipped and staffed for advanced resuscitation.

CONTRALATERAL ANESTHESIA IN TWO PATIENTS AFTER RETROBULBAR BLOCK

PURPOSE

To report a case series of two patients with contralateral anesthesia after retrobulbar block.

METHODS

Retrospective review of two cases and review of the literature.

RESULTS

Two patients of one practitioner received contralateral anesthesia after retrobulbar block for posterior segment surgery. Patient 1 suffered from transient contralateral akinesia, whereas Patient 2 experienced transient contralateral amaurosis.

CONCLUSION

Posterior spread of anesthetics is a rare but potentially serious complication of retrobulbar anesthesia caused by spread of anesthetics along the optic nerve sheath. Modification of injection technique can decrease the risk of this complication.

Combined Topical-Intracameral Anesthesia in Manual Small-Incision Cataract Surgery: A Prospective, Randomized, Double-Masked, Placebo-Controlled Trial

PURPOSE

To determine whether intracameral lidocaine plus topical anesthesia could further reduce patients' pain experience during manual small-incision cataract surgery, compared with topical anesthesia alone.

DESIGN

A prospective, randomized, double-masked, placebo-controlled clinical trial was conducted.

METHODS

This research was approved by the institutional review board of the Eye Hospital of Wenzhou Medical College in China. All patients gave written, informed consent, and no untoward pressure or coercion was used for the written informed consent. A total of 300 patients were randomly assigned into the placebo group (topical anesthesia plus intracameral balanced salt solution) or the interventional group (combined topical plus intracameral anesthesia). The pains they experienced during the different stages of the operation were evaluated by a visual analog pain scale. At the end of the surgery, the surgeon was given a questionnaire to evaluate the cooperation of the patient. The endothelial cell count was collected preoperatively and 1 month postoperatively.

RESULTS

The patient-reported pain scores were significantly lower in the interventional group at the following stages of the operation: nucleus rotation (P < 0.001), bisection of the nucleus (P < 0.001), and prolapse of the nucleus (P < 0.001). The surgeon assessment showed better patient cooperation in the lidocaine group (P = 0.04). There was no significant difference in endothelial cell loss between the 2 groups.

CONCLUSIONS

Although topical anesthesia alone provides acceptable anesthesia for manual small-incision cataract surgery, combined topical and intracameral anesthesia decreased patients' discomfort and increased their cooperation during the operation.

Superior subconjunctival anesthesia versus retrobulbar anesthesia for manual small-incision cataract surgery in a residency training program: a randomized controlled trial

PURPOSE

To evaluate the effectiveness of subconjunctival anesthesia as compared to retrobulbar anesthesia for pain control during manual small-incision cataract surgery (MSICS) performed by third-year residents.

DESIGN

A randomized, controlled trial.

PATIENTS AND METHODS

A total of 150 patients undergoing routine cataract surgery were randomly assigned to receive either subconjunctival anesthesia (group 1, n = 75) or retrobulbar anesthesia (group 2, n = 75). Third-year residents performed MSICS using the modified Blumenthal technique. Subconjunctival anesthesia was administered by injecting 2% xylocaine with adrenalin into the superior conjunctiva, and retrobulbar anesthesia by injecting 2 mL of 2% xylocaine with adrenalin into the retrobulbar space. We studied the following variables: intraoperative pain score rated on a 100-point visual analog scale (VAS), operative time, and injection and operative complications.

RESULTS

A mean age of 69 vs 70 years, an operative time of 47.1 (SD, 9.9) min vs 47.7 (10.9) min, and a median (interquartile range) pain score of 40 (range, 20-70) vs 40 (range, 20-50) were observed in the subconjunctival and the retrobulbar groups, respectively. The injection complication of subconjunctival hemorrhage was significantly higher in the subconjunctival group (25.3%) compared to the retrobulbar group (1.3%). The operative complication rate between groups was not different (P > 0.05).

CONCLUSION

Both, superior subconjunctival anesthesia and retrobulbar anesthesia were effective during MSICS when used in a residency training program.

Manual acupuncture for relieving pain associated with panretinal photocoagulation

OBJECTIVE

The feasibility of manual acupuncture for reducing pain associated with panretinal photocoagulation (PRP) was investigated.

METHODS

This was a prospective, comparative nonrandomized study on patients with proliferative diabetic retinopathy who were receiving PRP treatment. The protocol of PRP included three sequential sessions of treatment at 2-week intervals. Both the acupuncture (acuPRP) and control groups had no acupuncture in the first session. In the second session, acupuncture was given to the acuPRP group only. The third session of PRP completed the laser treatment course. Acupuncture performed only at GB 37 (Guāngmíng) just before PRP, and the needle was removed after the treatment. An 11-point Likert-type verbal pain score test was given to all patients after each PRP treatment.

RESULTS

Of 34 patients with proliferative diabetic retinopathy, 18 patients were allocated to the acuPRP group and 16 patients were allocated to the control group. After the first PRP treatment, there was no statistical difference in mean pain scores between the acuPRP and control groups (6.8±1.2 versus 6.3±2.1, respectively, p=0.383). After the second PRP treatment, the mean pain score in the acuPRP group was significantly lower, compared with the control group (3.9±1.8 versus 7.4±1.9, respectively, p<0.0001). Within the group, the mean pain scores were significantly higher during the second PRP treatment, compared with the first PRP treatment, in the control group (p=0.0003). In contrast, the mean pain scores were significantly lower during the second PRP treatment, compared with the first PRP treatment in the acuPRP group (p<0.0001). No adverse reactions or complications were noted.

CONCLUSIONS

Acupuncture might help reduce pain during PRP treatment. However, further randomized studies are necessary to verify these preliminary results.

Oral versus topical diclofenac for pain prevention during panretinal photocoagulation

PURPOSE

To investigate the effect of pretreatment oral and topical diclofenac on pain reduction during panretinal laser photocoagulation (PRP) for proliferative diabetic retinopathy (PDR).

DESIGN

Prospective, randomized, double-masked, placebo-controlled clinical trial.

PARTICIPANTS AND CONTROLS

A total of 90 patients with PDR requiring PRP for the first time were assigned randomly to 1 of 3 study groups: oral diclofenac (n = 30), topical diclofenac (n = 31), or placebo (n = 29).

METHODS

Study medications were administrated before the first PRP treatment, and pain levels experienced during and 15 minutes after PRP were recorded on a visual analog scale (VAS). Pain levels during a second PRP session, performed on a later date with no pretreatment medications, also were recorded on a VAS.

MAIN OUTCOME MEASURES

The primary outcome measures were the mean VAS pain scores during the first PRP treatment. Secondary outcome measures were the mean VAS pain scores 15 minutes after the first PRP and during the second PRP, and reported side effects after the first PRP.

RESULTS

Mean VAS pain scores during the first PRP were: oral diclofenac, 25.7+/-19.9; topical diclofenac, 33.8+/-27.9; and placebo, 41.3+/-31.0. The pain score difference between oral diclofenac and placebo was both clinically significant (>or=13) and statistically significant (P = 0.02), whereas differences between oral and topical diclofenac (P = 0.20) and topical diclofenac and placebo (P = 0.33) were not. Multivariate regression analysis for age, gender, and total laser energy demonstrated lower pain levels for both oral diclofenac (P = 0.015) and topical diclofenac (P<0.0001) versus placebo, but no difference between oral and topical diclofenac (P = 0.67). For the first PRP, all 3 groups had lower mean pain scores at 15 minutes after treatment compared with during treatment (P<or=0.0003). Mean pain scores were higher during the second compared with the first PRP for the oral diclofenac (P = 0.02) and placebo (P = 0.05) groups. No significant rate difference for any side effect was found between groups.

CONCLUSIONS

When given in a single dose, oral diclofenac is an effective pretreatment analgesic agent for reducing the pain experienced during PRP for PDR.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Real-time visualization of ultrasound-guided retrobulbar blockade: an imaging study

BACKGROUND

Retrobulbar anaesthesia allows eye surgery in awake patients. Severe complications of the blind techniques are reported. Ultrasound-guided needle introduction and direct visualization of the spread of local anaesthetic may improve quality and safety of retrobulbar anaesthesia. Therefore, we developed a new ultrasound-guided technique using human cadavers.

METHODS

In total, 20 blocks on both sides in 10 embalmed human cadavers were performed. Using a small curved array transducer and a long-axis approach, a 22 G short bevel needle was introduced under ultrasound guidance lateral and caudal of the eyeball until the needle tip was seen 2 mm away from the optic nerve. At this point, 2 ml of contrast dye as a substitute for local anaesthetic was injected. Immediately after the injection, the spread of the contrast dye was documented by means of CT scans performed in each cadaver.

RESULTS

The CT scans showed the distribution of the contrast dye in the muscle cone and behind the posterior sclera in all but one case. No contrast dye was found inside the optic nerve or inside the eyeball. In one case, there could be an additional trace of contrast dye behind the orbita.

CONCLUSIONS

Our new ultrasound-guided technique has the potential to improve safety and efficacy of the procedure by direct visualization of the needle placement and the distribution of the injected fluid. Furthermore, the precise injection near the optic nerve could lead to a reduction of the amount of the local anaesthetic needed with fewer related complications.

Brainstem anaesthesia after retrobulbar block: A rare cause of coma presenting to the emergency department

Local anaesthesia, in particular retrobulbar block, is commonly used to perform cataract surgery. Known complications of retrobulbar block include cranial nerve palsies, seizures and cardiorespiratory arrest. We report a case of brainstem anaesthesia causing apnoea and loss of consciousness in a man who received retrobulbar block. The likely mechanism is inadvertent dural puncture of the optic nerve sheath and local anaesthetic injection into the cerebrospinal fluid space. As in this case, the literature reports a short-lived period of anaesthesia with usually no long-term sequelae. Although rare, it is a life-threatening complication if the patient is not appropriately resuscitated. This case highlights the need for trained personnel, with suitable monitoring and adequate resuscitation facilities in order to perform this technique.

Bilateral hearing loss following a retrobulbar block

PURPOSE

Regional anesthesia is the most commonly used ophthalmological anesthetic technique in Canada and the United States. Brainstem anesthesia is not an uncommon complication of retrobulbar blocks. Anesthesiologists are a prominent element in the ophthalmology suite, in part due to the complications possible with regional anesthesia. This is the first reported case of complete bilateral hearing loss following a retrobulbar block.

CLINICAL FEATURES

A 46-yr-old male with type 1 diabetes mellitus presenting for ophthalmological surgery had a retrobulbar block performed by the ophthalmologist. Local anesthetic was injected through a 25 G, 1.5 inch needle, entering the orbit inferiorly on the temporal third of the lower lid. Shortly after the block was completed the patient experienced sudden hearing loss. On examination the hearing loss appeared to be complete and bilateral. The patient was alert and oriented; the remainder of the cranial nerve exam was normal. The patient's hearing loss gradually improved and three hours after the block his hearing had subjectively returned to normal.

CONCLUSION

Brainstem anesthesia is not a rare complication of regional anesthesia for ophthalmological surgery. Symptoms include confusion, mental agitation, dizziness, blurred vision or blindness, ophthalmoplegia, deafness, tinnitus, dysphagia, dysarthria, respiratory depression to apnea, and/or limb paralysis. A connection between the subdural and subarachnoid spaces and the optic sheath exists. The effect on the central nervous system depends upon the amount of local anesthetic injected and the area to which it spreads.

Interventions for relieving pain associated with panretinal photocoagulation: a prospective randomized trial

PURPOSE

To evaluate the efficacy of pain relief by oral diazepam, acetaminophen, mefenamic acid, intramuscular ketorolac tromethamine, and peribulbar anaesthesia in panretinal photocoagulation (PRP).

METHODS

A total of 220 patients with proliferative diabetic retinopathy requiring PRP treatment were enrolled in this study. Before laser treatment, the patients were allocated randomly to one of eight groups: group 1: diazepam (n=22), group 2: acetaminophen (n=21), group 3: mefenamic acid (n=21), group 4: diazepam and acetaminophen (n=22), group 5: diazepam and mefenamic acid (n=22), group 6: peribulbar anaesthesia with lidocaine (n=23), group 7: intramuscular injection of ketorolac tromethamine (n=22), group 8: placebo (n=67). Pain after the laser treatment was assessed by a verbal descriptive scale. Blood pressure and heart rate were measured before and after laser treatment.

RESULTS

Patients receiving peribulbar anaesthesia had a significantly lower pain score than the control group (P<0.0001). Additionally, the peribulbar anaesthesia-treated group had the significantly least PRP-associated rise in either systolic (P=0.043) or diastolic blood pressure rates (P=0.030). There were no significant differences in pain score using other anesthetic agents when compared with the control group. There were no significant changes in heart rate after PRP treatment.

CONCLUSION

Peribulbar anaesthesia is effective in reducing pain and blood pressure increase after PRP treatment. Oral diazepam, mefenamic acid, and acetaminophen (either alone or in combination with each other) are not effective in preventing PRP treatment-associated pain. Intramuscular injection of ketorolac tromethamine is also not effective in reducing PRP-associated pain.

Prospective study comparing lidocaine 2% jelly versus sub-Tenon's anaesthesia for trabeculectomy surgery

AIMS

To compare the analgesic properties of lidocaine 2% jelly versus sub-Tenon's anaesthesia with lidocaine 2% without adrenaline (epinephrine) for trabeculectomy surgery.

METHODS

A prospective randomised clinical trial. 59 consecutive patients scheduled for trabeculectomy at the Toronto Western Hospital were randomly assigned to topical unpreserved lidocaine 2% jelly or sub-Tenon's anaesthesia with 2% lidocaine. Both groups received a standardised sedative consisting of midazolam, fentanyl. and/or propofol. The visual analogue scale was utilised to measure intraoperative pain. Patient comfort, physician assessment of intraoperative patient compliance, volume of local anaesthetic used, need for supplemental anaesthesia, and any complications were recorded. The two groups were compared using the Student's t test.

RESULTS

The sub-Tenon's anaesthesia group and the lidocaine 2% jelly group did not vary significantly in subjective pain score (18.3 (SD 16.2) v 19.8 (12.4) respectively, p = 0.739) and surgeons' satisfaction scale (3.6 (0.7) and 3.8 (0.6) respectively, p = 0.328). Four patients required additional anaesthesia, all of them in the sub-Tenon's group.

CONCLUSION

Topical lidocaine 2% jelly is as effective as sub-Tenon's anaesthesia for pain control in patients undergoing trabeculectomy. Lidocaine 2% jelly is similar to sub-Tenon's anaesthesia in patient comfort and surgeon satisfaction.

An audit of peribulbar blockade using 15 mm, 25 mm and 37.5 mm needles, and sub-Tenon's injection*

The efficacy of peribulbar anaesthesia performed with short, medium and long needles, with sub-Tenon's injection as a control, was audited. Two hundred patients undergoing cataract surgery underwent peribulbar injection using 25G needles of the following lengths: 15 mm, 25 mm or 37.5 mm. Sub-Tenon's injections were performed with a curved 25-mm sub-Tenon anaesthesia cannula. The injection technique, ocular akinesia and analgesia scoring system, and supplementary injection protocols were standardised. After initial injections of local anaesthetic via the sub-Tenon's cannula or with 37.5 mm, 25 mm and 15 mm needles, supplementation was required in one (2%), 13 (26%), 22 (44%) and 32 (64%) of patients, respectively; the total number of supplementary injections required were 1, 16, 35 and 47, respectively. It is concluded that the efficacy of peribulbar anaesthesia depends upon the proximity of the deposition of local anaesthetic solution either to the globe or orbital apex. These data justify the classification of peribulbar anaesthesia into: circum-ocular (sub-Tenon's, episcleral), peri-ocular (anterior, superficial); peri-conal (posterior, deep) and apical (ultra-deep) for teaching purposes.

Complications of ophthalmologic nerve blocks: a review

Complications of ophthalmologic nerve blocks are rare, but they can have serious life- and sight-threatening consequences. Knowledge of the potential complications is essential for the anesthesiologist who performs ophthalmologic nerve blocks. However, most anesthesiologists are unfamiliar with these complications because the majority have been reported in the ophthalmology literature. We review the complications that may occur during the placement of ophthalmologic blocks and their appropriate prompt treatment.

Combined topical anesthesia and sedation for open-globe injuries in selected patients

PURPOSE

To evaluate the efficacy and safety of topical anesthesia (TA) and IV sedation in surgery for less severe open-globe injury (OGI).

DESIGN

Noncomparative consecutive interventional case series.

PARTICIPANTS

Of 67 OGI cases reviewed at the Department of Ophthalmology and Otolaryngology, University of Bari, Bari, Italy, in the period from 1999 to 2000, 10 eyes (14.9%) of 10 consecutive patients (age range, 6-58 years) were repaired using TA and IV sedation. All patients belonged to the American Society of Anesthesiologists risk class I or II. Nine eyes had corneoscleral wounds, four had vitreous loss, two had traumatic cataract, and three had an intraocular foreign body (IOFB); one patient had interruption of a continuous penetrating keratoplasty suture. Preoperatively, best-corrected visual acuity (BCVA) ranged from hand movement to 20/20.

INTERVENTION

Corneoscleral suture was performed in nine patients, vitreous excision in four, uveal excision or reposition in four, IOFB removal in three, and cataract extraction in two; corneal button resuture was carried out in one patient. All patients received topical oxybuprocaine hydrochloride 0.4%, and IV propofol, midazolam, and fentanyl for anesthesia.

MAIN OUTCOME MEASURES

The change in BCVA was evaluated. Within 24 hours after surgery, each patient was asked to grade subjective pain and discomfort on a 4-point scale. The surgeon was asked to report difficulties attributable to the operating conditions. Complications related to anesthesia and to surgery were assessed.

RESULTS

Best-corrected visual acuity stabilized or improved in all patients. All patients had grade 1 pain and discomfort during most of the procedure. All patients had grade 2 (mild) pain and discomfort during external bipolar cautery and conjunctival closure. No patient required additional anesthesia. The operating conditions as reported by the surgeons were graded slightly difficult in all cases but one, which was graded moderately difficult. No patient had surgical or anesthesia-related adverse events or life-threatening complications.

CONCLUSIONS

Topical anesthesia and IV sedation are safe and effective and could be a reasonable alternative for less severe OGI. The degree of patient discomfort is only marginal during surgery and postoperatively. However, surgical training and patient preparation are the keys to the safe use of this anesthetic modality.

Apnea and seizures following retrobulbar local anesthetic injection

Surgery on the eye is performed using topical anesthesia, retrobulbar anesthesia, peribulbar anesthesia, and general anesthesia. Retrobulbar anesthesia is associated with a number of complications that include apnea (respiratory arrest), seizures, or both. Although these complications are transient and self-limiting, they can be life-threatening if not recognized and treated early. We report two patients who developed apnea, one of whom had cardiorespiratory arrest; and two other patients who presented with seizures. We provided ventilation with 100% oxygen, treated the hypertension with nicardipine, and the tachycardia with esmolol. The patients did not have any residual complications.

Local anesthesia with intravenous sedation for surgical repair of selected open globe injuries

PURPOSE

To report factors associated with the use of local anesthesia with intravenous sedation (local anesthesia/sedation) rather than general anesthesia for surgery for open globe injuries in adult reparable eyes.

DESIGN

Retrospective, nonrandomized, comparative case series.

METHODS

Medical records were reviewed of all patients with open globe injuries repaired at Bascom Palmer Eye Institute between 1995 and 1999. "Adult reparable eyes" (eyes in patients >/=18 years of age, not treated with primary enucleation or evisceration, followed up >/=2 months) were included.

RESULTS

In all, 220 eyes of 218 patients met inclusion criteria. General anesthesia was employed in 80 of 200 (36%) and local anesthesia/sedation in 140 of 220 (64%). Patients who had local anesthesia/sedation were significantly more likely to have an intraocular foreign body (31% vs 14%; P =.010, chi-square test), better presenting visual acuity (1.8 logMAR [logarithm of the minimum angle of resolution] units vs 2.5 logMAR units; P <.001, t test), more anterior wound location (75% corneal/limbal vs 65%; P =.003, chi-square), shorter wound length (6.3mm vs 10.8mm; P <.001, t test), and dehiscence of previous surgical wound (26% vs 12%; P =.021, chi-square) and were significantly less likely to have an afferent pupillary defect (22% vs 51%; P <.001, chi-square). There was no anesthesia-related complication in either group. The local anesthesia/sedation group had a shorter mean operating time than did the general anesthesia group (78 minutes vs 117 minutes; P <.001, t test). The general anesthesia group had a longer mean follow-up than the local anesthesia/sedation group (20.2 months vs 13.9 months, respectively; P =.002, t test). Change in visual acuity between the presenting and final examinations was similar for open globe injuries repaired with general anesthesia compared with local anesthesia/sedation (0.94 vs 0.72 logMAR units of visual acuity, respectively; P =.16, t test).

CONCLUSIONS

Local anesthesia/sedation is a reasonable alternative to general anesthesia for selected patients with open globe injuries.

A comparison of topical and retrobulbar anesthesia for trabeculectomy

PURPOSE

To compare the safety and efficacy of topical versus retrobulbar anesthesia for primary trabeculectomy

METHODS

A prospective study of 36 consecutive patients undergoing trabeculectomy who were randomized to receive topical (n = 18) or retrobulbar (n = 18) anesthesia. Operating conditions, patient comfort, and surgical outcome were evaluated.

SETTINGS

Tertiary-care university hospital ambulatory surgical center.

RESULTS

There were no differences in operating conditions (P = 0.14), pain during (P = 0.54) or after (P = 0.76) surgery, or supplemental anesthesia required (P = 0.34) between the two groups. Very few patients in either group were bothered by touch sensation, tissue manipulation, or the microscope light. Chemosis, subconjunctival hemorrhage and eyelid hemorrhage were seen exclusively in the retrobulbar group (P <0.03), and were all attributable to the injection. Inadvertent eye movement was present more frequently in the topical group (P = 0.01), although this did not pose a problem to the surgeon. No surgical complications were encountered in either group.

CONCLUSION

Topical anesthesia is a safe and effective alternative to retrobulbar anesthesia for primary trabeculectomy.

Exposure keratopathy following phacoemulsification under local anaesthesia

PURPOSE

Report a series of patients with exposure keratopathy following phacoemulsification under local anaesthesia.

METHODS

A case series.

RESULTS

Four patients were found to have exposure keratopathy within hours after surgery resulting in a visit to the casualty on the day of surgery.

CONCLUSIONS

One should anticipate the possibility of lagophthalmos and assess the blink reflex at the end of surgery. If the reflex is poor, patching the eye or taping the lids should be undertaken to prevent this complication.

Topical anesthesia in phacotrabeculectomy

PURPOSE

To study the safety and efficacy of topical anesthesia alone, without systemic sedation, in phacotrabeculectomy for cataract and primary open-angle glaucoma.

METHODS

In this prospective study, topical anesthesia with 2% lidocaine hydrochloride jelly without systemic sedation was used for combined phacoemulsification, posterior chamber intraocular lens implantation, and trabeculectomy in consecutive patients with primary open-angle glaucoma and concurrent cataract at the United Christian Hospital, Kowloon, Hong Kong, from September 2000 to May 2001. Visual analog pain score and change in vital signs were used to assess the intraoperative pain experience. Other outcome measures included postoperative visual acuity and intraocular pressure at 3 months.

RESULTS

Twenty-two eyes of 22 consecutive patients were included in the study. The mean intraoperative pain score was 0.9 (range, 0-3). Three patients reported discomfort intraoperatively. No injection of supplementary anesthetic was required in any of the eyes. None of the patients had significant increase of pulse rate or blood pressure during the whole surgical procedure. Six patients required oral analgesic for postoperative discomfort. The mean preoperative medically treated IOP was 20.3 +/- 5.9 mm Hg and the mean postoperative IOP at 3 months was 14.4 +/- 4.7 mm Hg. All except two patients had improved visual acuity. There was no serious intraoperative or postoperative complication.

CONCLUSION

Topical 2% lidocaine hydrochloride jelly without systemic sedation may be a safe and effective anesthetic method in phacotrabeculectomy for patients with primary open-angle glaucoma with coexisting cataract.

Local anaesthesia for vitreoretinal surgery: an audit of patient and surgical experience

PURPOSE

Local anaesthesia for vitreoretinal surgery is little used as these procedures are deemed to be too long and uncomfortable for patients to tolerate. In this unit anterior intraconal local anaesthesia is used for most routine surgery. We undertook an audit to ensure that surgical standards and patient acceptability were not compromised.

METHODS

A prospective observational audit was performed. Audit data included: Grade of anaesthetist and surgeon; details of anaesthetic and operation; compliance of patient; operating conditions and pain scores. Anaesthesia was provided with a combined peribulbar and intraconal anaesthetic, using bicarbonate buffered lignocaine and bupivacaine 50:50 mixture.

RESULTS

135 (76%) had local anaesthesia alone, 13 (7%) had local anaesthesia with sedation and 29 (16%) had general anaesthesia. 96.4% of patients were compliant and 98.8% of operating conditions were good or excellent. The mean perioperative pain score was 0.1 (range of 0-1), 97% said they would choose local anaesthesia again.

CONCLUSIONS

LA for vitreoretinal surgery is a useful and flexible method of anaesthesia, which has been shown to have excellent patient tolerance.

Efficacy of lignocaine gel for outpatient laser treatment in inflamed eyes

PURPOSE

To evaluate the efficacy and safety of topical 2% lignocaine gel in providing analgesia during outpatient transpupillary or trans-scleral laser treatment of inflamed eyes.

METHODS

A prospective study was carried out of consecutive eligible eyes undergoing laser treatment using 2% lignocaine gel as a topical anaesthetic and a coupling medium. At the conclusion of each procedure, patients were asked to grade a pain score (0 = no discomfort, 1 = mild discomfort, 2 = mild pain, 3 = moderate pain, 4 = severe pain).

RESULTS

Twenty eyes in 19 patients received laser treatment. No pain was reported in 95% of cases treated (no discomfort in 75%, mild discomfort in 20%) and only mild pain in 5% (one patient). No adverse reactions were encountered in any of the patients. There were no complications associated with the procedures.

CONCLUSIONS

Lignocaine 2% gel is safe and effective for outpatient transpupillary and trans-scleral laser treatment in inflamed eyes, providing adequate analgesia and serving as a coupling medium at the same time.

Anesthesia for intraocular surgery

Surgeons must decide on the type of anesthesia to use when performing cataract surgery. These "viewpoints" articles provide a well-balanced discussion offering the pros and cons of both topical anesthesia and retrobulbar/peribulbar injection. Dr. Dutton gives an overview of both techniques, focusing on relevant orbital anatomy. Drs. Hassan, Edelhauser and Kim, review the various types of topical anesthesia currently in use, and Drs. Spriggs and Broocker examine retrobulbar and peribulbar injections. Both techniques are associated with advantages and risks, so each surgeon must decide which technique is best suited for his or her own practice.

Topical versus sub-Tenon's anesthesia without sedation in cataract surgery

PURPOSE

To compare pain control using topical anesthesia with that using sub-Tenon's anesthesia for clear corneal phacoemulsification cataract surgery and foldable intraocular lens (IOL) implantation.

SETTING

Departments of Ophthalmology, General Hospital Asklepeion Voulas and General Hospital of Athens, University of Athens, Athens, Greece.

METHODS

One hundred consecutive patients scheduled for bilateral cataract surgery 1 to 2 months apart were prospectively randomized to receive topical anesthesia (100 eyes) or sub-Tenon's anesthesia (100 eyes). The randomization was stratified so that one half of first-eye surgeries and one half of second-eye surgeries were assigned to each anesthesia group, with each patient receiving each type of anesthesia once. All patients had clear corneal phacoemulsification with foldable IOL implantation. Patients were asked to rate their pain level on a 10-point scale for 4 periods: during the administration of the anesthetic agent, during surgery, immediately after surgery, and 24 hours postoperatively. The surgeon recorded his subjective assessment of ease of surgery and surgical complications using a standardized template.

RESULTS

Eighty-one percent of patients who received topical anesthesia and 8% of patients who received sub-Tenon's anesthesia reported no pain during delivery of the anesthetic agent. The mean pain score was 0.19 +/- 0.39 (SD) in the topical group and 1.35 +/- 0.63 in the sub-Tenon's group. The difference between groups was statistically significant (P <.001). Seventy-two percent of patients in the topical anesthesia group and 86% in the sub-Tenon's anesthesia group reported no pain or slight discomfort during surgery (mean score 1.13 +/- 1.57 and 0.57 +/- 1.28, respectively) (P <.001). Ninety percent of topical anesthesia patients and 100% of sub-Tenon's anesthesia patients reported no pain or slight discomfort 30 minutes postoperatively (mean score 0.80 +/- 0.93 and 0.12 +/- 036, respectively) (P <.001). All patients in the topical anesthesia group and 77% in the sub-Tenon's group reported no pain 24 hours postoperatively (mean pain 0.00 +/- 0.00 and 0.23 +/- 0.40, respectively) (P <.001). Complications including prolonged akinesia of the globe, chemosis, and conjunctival hemorrhage occurred significantly more frequently in the sub-Tenon's than in the topical group (P <.001).

CONCLUSIONS

Patients having cataract surgery under topical anesthesia had more intraoperative and postoperative discomfort than patients receiving sub-Tenon's anesthesia. However, patients having topical anesthesia reported less pain during its administration and had fewer complications. Both anesthesia methods provided high levels of pain control without additional sedation.

Local anaesthesia for 1221 vitreoretinal procedures

BACKGROUND

Vitreoretinal (VR) surgery has been increasingly performed under local anaesthesia (LA) in this unit. The results of an audit monitoring this change are presented.

METHODS

Data were collected on 1497 patients including type, volume, and position of the anaesthetic block, type of surgery, complications, and patient reactions.

RESULTS

1221/1479 (82%) patients had LA. They were older than those having general anaesthesia (GA) 63.5 years v 45.9 years; 146 (10.6%) blocks were intracone, 130 (10.6%) peribulbar, and 927 (75.9%) combined. Operations included 436 vitrectomies, 545 retinopexy with or without vitrectomy, and 238 buckling procedures. Some pain was felt by 9.4%, 8.8%, and 19.7% of patients during vitrectomy, retinopexy with or without vitrectomy, and buckling surgery respectively.

CONCLUSION

Local anaesthesia for VR surgery is well tolerated by patients, being effective throughout longer and more stimulating ocular surgery.

A double-blind randomised comparison of ropivacaine 0.5%, bupivacaine 0.375% - lidocaine 1% and ropivacaine 0.5% - lidocaine 1% mixtures for cataract surgery

This study evaluated the efficacy and side-effects of plain ropivacaine compared with ropivacaine-lidocaine and bupivacaine-lidocaine mixtures for peribulbar blocks in cataract surgery. Ninety patients were randomly allocated to three groups and received peribulbar blockade using one of the three solutions. Speed of onset and quality of blockade were assessed using akinesia, surgical satisfaction and patient satisfaction. Complications and cardiovascular side-effects were noted. There was a slower onset of akinesia using ropivacaine alone, although at 10 min after injection all groups were equal in this respect. There was no difference in surgical or patient satisfaction between the groups. There were no differences in pain on injection, preblock and postblock blood pressure, heart rate or oxygen saturation. The optimal time to surgical incision after peribulbar blockade is not less than 15 min and plain ropivacaine fulfils this criterion.

Retrobulbar versus systemic application of morphine during titratable regional anesthesia via retrobulbar catheter in intraocular surgery

IMPLICATIONS

We investigated the effects of morphine on postoperative pain in patients undergoing intraocular surgery using a new indwelling catheter. Although morphine produced central analgesic effects, there was no evidence for the involvement of peripheral opioid receptors in the modulation of ocular pain.

Sub-Tenon's injection for local anesthesia in posterior segment surgery

OBJECTIVE

To determine whether the sub-Tenon's parabulbar approach for local anesthesia is a safe and effective choice for posterior segment surgery.

DESIGN

Prospective, noncomparative case series.

PARTICIPANTS

Two hundred seventy-six consecutive patients underwent posterior segment surgery at the University of Texas Medical Branch.

INTERVENTION

Two hundred patients received sub-Tenon's parabulbar anesthesia containing an 11 -ml mixture of 5-ml 2% lidocaine (Xylocaine), 5-ml 0.5% bupivacaine (Marcaine), and 1 ml of 150 hyaluronidase (Wydase) units as primary anesthesia. The method did not involve a separate transcutaneous lid nerve or subconjunctival injection.

MAIN OUTCOME MEASURES

The proportion of cases receiving supplementation (significant intravenous anesthesia, intraoperative local anesthesia, or both) was estimated. Its relationship to duration of surgery and surgical procedures deemed painful was assessed. Surgery lasting 3 hours or more was considered a long duration. Both scleral buckle and cryotherapy were considered painful procedures. The proportion of cases receiving additional local anesthesia preoperatively was also evaluated. Complications associated with sub-Tenon's parabulbar injection were monitored.

RESULTS

There were 101 instances of patients receiving additional anesthesia. Nineteen received additional preoperative sub-Tenon's anesthesia, 12 received intraoperative local anesthesia supplementation, and 70 received intravenous medication. Of these 70, 19 required what the authors defined as a significant amount of intravenous medication, three of whom also received intraoperative local anesthesia supplementation. Consequently, 28 of 200 patients (14%; 95% confidence interval: 9.5, 19.6) received supplementation (significant intravenous anesthesia, intraoperative local anesthesia, or both). The proportion of cases receiving supplementation was directly related to duration of surgery. Patients involved in longer cases (51.7% vs. 7.6%; P < 0.001) and those involved in more painful procedures (48.2% vs. 8.7%; P < 0.001) were more likely to receive supplementation. Adjusting for surgery duration, a greater proportion of patients undergoing painful procedures required supplementation (31.3% vs. 0.5% for surgery < 3 hours, P = 0.003; 72.7% vs. 38.9% for surgery > or = 3 hours, P = 0.13). No associated ocular or systemic complications were observed.

CONCLUSIONS

The results of this large study demonstrate that a single injection of sub-Tenon's anesthesia is relatively safe and effective for achieving local anesthesia during vitrectomies, with or without other intraocular procedures, lasting less than 3 hours. Other types of posterior segment surgery may require supplementation if they are more painful procedures, such as scleral buckle or cryotherapy, or last longer than 3 hours.

Topical anesthesia for phacoemulsification, intraocular lens implantation, and posterior vitrectomy

PURPOSE

To evaluate the efficacy of topical anesthesia as an alternative to peribulbar or retrobulbar anesthesia in phacoemulsification and intraocular lens (IOL) implantation combined with pars plana vitrectomy.

SETTING

Clinica de Ojos de Maracaibo, Maracaibo, and the Retina and Vitreous Service, Clinica Oftalmologica Centro Caracas, Caracas, Venezuela.

METHODS

In this prospective study, phacoemulsification, IOL implantation, and posterior vitrectomy using topical anesthesia (lidocaine 4% drops) were prospectively performed in 45 eyes (45 patients) with varied vitreoretinal pathology including macular holes, epiretinal membranes, subfoveal neovascular membranes, proliferative diabetic retinopathy, and vitreous hemorrhage. Preoperative and intraoperative sedation of varying degrees was necessary. Subjective pain and discomfort were graded from 1 (no pain or discomfort) to 4 (severe pain and discomfort).

RESULTS

All patients had grade 1 pain and discomfort during most of the procedure. All patients had grade 2 (mild) pain and discomfort during pars plana sclerotomies, external bipolar cautery, and conjunctival closure. The mean amount of lidocaine 4% drops required during each procedure was 0.5 mL. No patient required additional retrobulbar, peribulbar, or sub-Tenon's anesthesia.

CONCLUSIONS

This technique avoids the risks of globe perforation, retrobulbar hemorrhage, and prolonged postoperative akinesia of the eye at a lower cost. With appropriate case selection, topical anesthesia was a safe and effective alternative to peribulbar or retrobulbar anesthesia in phacoemulsification and IOL implantation combined with posterior 3-port pars plana vitrectomy.

Brainstem anesthesia presenting as dysarthria

After having a retrobulbar injection for anesthesia before cataract surgery, a patient developed dysarthria. This was the presenting sign for penetration of the optic nerve sheath by the retrobulbar injection, with subsequent brainstem anesthesia. Thereafter, the patient demonstrated cranial nerve dysfunctions with tongue deviation, tachycardia, hypertension, and contralateral sixth and third nerve palsies. I believe this is the first documented case in which dysarthria is the presenting sign for brainstem anesthesia resulting from a retrobulbar injection.

The National Survey of Local Anaesthesia for Ocular Surgery. II. Safety profiles of local anaesthesia techniques

PURPOSE

To describe the adverse events associated with local anaesthesia (LA) for intraocular surgery.

METHODS

An observational study of practice of LA in the whole of the United Kingdom was conducted over 3 months in late 1996. Staff in all ophthalmology theatres in the National Health Service were invited to report every LA given for the purpose of intraocular surgery during the first week, and thereafter to report adverse events only.

RESULTS

During the first week, the reported incidence of all adverse events within the orbit was 2.7%, and for 'systemic' adverse events it was 0.9%. Serious adverse events were reported in association with all LA techniques. In 3 months, 18 events were described as 'life-threatening' by respondents, and further patients were reported to have had epileptic fits or were transferred directly from the operating theatre to an intensive care unit. The voluntary nature of the survey introduces some bias from under-reporting, making the incidence of these severe events difficult to assess. Reported incidence of severe 'systemic' adverse events was similar for all LA techniques.

CONCLUSIONS

Serious adverse events were reported in association with with all LA techniques. This implies that we should be prepared for such events in all patients who have intraocular surgery.