Whatʼs new in ophthalmic anaesthesia?

Continuation of aspirin therapy before pars plana vitrectomy: Safe or not?

PURPOSE

To assess the safety of pars plana vitrectomy (PPV) in patients undergoing systemic treatment with aspirin.

METHODS

This prospective study enrolled consecutive patients undergoing PPV under percutaneous retrobulbar anesthesia between February 2016 and July 2018. Sixty-seven eyes from 67 patients on regular aspirin therapy were randomized into two groups: the continuation group (33 eyes), with aspirin continued during the perioperative period; and the discontinuation group (34 eyes), with aspirin discontinued for 3 to 7 days before surgery. Forty-three eyes from 43 patients who had no antiplatelet/anticoagulant therapy were used as a control group.

RESULTS

There was no significant difference in the incidence of hemorrhagic complications or the need for additional operations due to hemorrhagic complications among the three groups (p = 0.740 and p = 0.324, respectively). None of the patients in these three groups suffered from thromboembolic events during the follow-up period. Except for one case (3.0%) of lid ecchymosis in the continuation group, no eye experienced bleeding complications associated with the retrobulbar local anesthesia. In the continuation group, three eyes (9.1%) demonstrated postoperative hyphema that resolved spontaneously. In the discontinuation group, two eyes (5.9%) suffered from postoperative vitreous hemorrhage, of which one eye required secondary surgery and the other cleared spontaneously. One eye (2.9%) in the discontinuation group demonstrated postoperative hyphema that absorbed spontaneously. Three eyes (7.0%) in the control group experienced hyphema that absorbed spontaneously.

CONCLUSION

The outcomes of our study indicate that PPV under retrobulbar anesthesia can be safely performed without discontinuing systemic aspirin therapy.

Advanced Subconjunctival Anesthesia for Cataract Surgery

PURPOSE

Ocular regional blocks generally require blind instrumentation to the posterior orbit, leading to rare but serious complications. However, topical anesthesia does not suppress eye or lid movements and may lead to more surgical complications. Advanced subconjunctival anesthesia (ASCAN) is a technique developed to provide reliable akinesia and anesthesia without anterior dissection or blind intrusion into the posterior orbit, while allowing visualization of the needle-tip position.

DESIGN

Nonrandomized case series at a rural health service.

METHODS

Advanced subconjunctival anaesthesia was performed on 60 elective adult patients undergoing phacoemulsification surgery. The technique involves piercing the conjunctiva and Tenon's capsule in the superior outer quadrant of the globe with a 25-gauge, 16 mm needle, using either lignocaine 2% plain or in equal mix with bupivicaine 0.5%. Up to 10 mL of anesthetic with hyaluronidase 30 IU/mL is injected in a posterior direction into the sub-Tenon's space. Ocular motor functions were assessed 10 minutes after ASCAN using a Brahma scale. Pain was assessed during surgery and at the end of surgery after subconjunctival injection of antibiotic and steroid using a verbal Numeric Rating Scale.

RESULTS

All patients completed surgery without needing supplemental anesthesia. Fifty-eight patients (97%) were pain free, whereas 2 patients experienced transient mild pain. Adequate globe akinesia and reliable lid paralysis was achieved comparable to other studies, with no major surgical or anesthetic complications.

CONCLUSIONS

Advanced subconjunctival anesthesia is a visually guided, minimally invasive technique, achieving satisfactory analgesia and akinesia for phacoemulsification surgery.

Dexamethasone Compared to Dexmedetomidine as an Adjuvant to Local Anesthetic Mixture in Peribulbar Block for Vitreoretinal Surgery. A Prospective Randomized Study

BACKGROUND

Dexamethasone or dexmedetomidine may improve the quality of peribulbar block.

AIM

The aim of this study is to compare the effects of adding either dexamethasone or dexmedetomidine to peribulbar block on the efficacy, intraocular pressure (IOP), time to first analgesic request, total analgesic requirement, and side effects in patients undergoing vitreoretinal surgery.

DESIGN

This was a clinical prospective randomized study.

PATIENTS AND METHODS

One hundred and fifty adult patients scheduled for vitreoretinal surgery with peribulbar block were randomized into three groups (50 patients each). Group I received 3.5 ml of 0.5% bupivacaine and 3.5 ml of 2% lidocaine + 1 ml normal Saline. 4 mg dexamethasone and 25 μg dexmedetomidine in 1 ml were added to the local anesthetic mixture in Groups II and III respectively. Onset and duration of sensory and motor blocks, adequate time to start surgery, IOP, time to first request of rescue analgesia, total analgesic consumption, and side effects were recorded. The statistical software SPSS 16 was utilized for statistical analysis.

RESULTS

Dexamethasone and dexmedetomidine groups showed significantly prolonged duration of corneal anesthesia (234.07 ± 1.37 and 233.54.1.97 min respectively), prolonged lid and globe akinesia (194.27 ± 1.63 and 194.73 ± 2.35 min respectively) with prolonged time to first request of analgesia and less consumption of rescue analgesia as compared to control group (P < 0.05) with non significant differences between both groups (P > 0.05). The onset of corneal anesthesia as well as lid and globe akinesia were enhanced in dexmedetomidine group compared to the other two groups (P < 0.05). In addition, the measurement of IOP was significantly less in the dexmedetomidine group after 10 min. All the patients were hemodynamically stable with no side effects observed.

CONCLUSION

The addition of dexamethasone and dexmedetomidine to local anesthetic mixture in peribulbar block for vitreoretinal surgeries provided safe and effective block with prolonged duration and decreased requirements of postoperative analgesia with better quality for dexmedetomidine group regarding the fast onset of the block and reduced IOP.

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.

Anesthetic management of ophthalmic surgery

Ophthalmic surgery presents challenges for the anesthesiologists, including control of intraocular pressure, prevention and management of the oculocardiac reflex. In addition to understanding ocular anatomy and physiology, the anesthesiologists must have possess technical expertise and knowledge of ophthalmic drug's systemic effects. Patients undergoing ophthalmic surgery have extremes of age and several medical diseases, like as hypertension, diabetes mellitus, coronary heart disease, chronic renal failure, and chronic obstructive lung disease. Anesthesiologist should be knowledgeable about the content as stated above to perform safe and desirable anesthesia for ophthalmic surgery.

Anaesthesia for ophthalmologic surgical procedures in a patient with advanced amyotrophic lateral sclerosis: a case report

Introduction

Anaesthesia procedures for surgical interventions in patients with amyotrophic lateral sclerosis (ALS) are not commonly found in clinical practice, and often have special considerations that must be taken into account in treatment planning. As a result, these procedures are rarely subject to publication, rendering it difficult for the anaesthesiologists to find useful and reliable information on this topic. ALS also presents a contraindication to the use of nondepolarising neuromuscular blocking drugs during general anaesthesia.

Case presentation

In the case presented here, a 52-year old, White man, the progression of the disease to tetraparesis and respiratory failure, in addition to having the patient on chronic mechanical ventilation support, provided additional challenges to the handling team. The maturation of cataracts severely impaired communication with the patient, and surgical treatment of the cataract presented the only means to save communication. Such interventions are generally performed under local anaesthesia with the advice of the attending anaesthesiologist. However, in this case the patients' announcements during the operation would be unreadable to the advising anaesthesiologist. Here, the authors share experiences from a successfully applied combination of topical and general anaesthesia for two cataract operations and a vitrectomy. This was tolerated well by the patient, and without any side-effects.

Conclusion

The applied treatment resulted in a substantial improvement of the vision and allowed communication to be maintained with the patient.