Injectable Anesthesia – How Risky Is It?

By Dean C. Brick, MD

Digest, Spring 1998

It remains one of the most dreaded events in ophthalmic surgery. The eye is prepped for retrobulbar anesthesia. The injection is attempted, but the patient moves and the surgeon is unable to accurately gauge the position of the needle and perforates the globe. Surgery is canceled and attention turns to managing the ensuing complications. Despite prompt treatment and follow-up, the patient’s visual outcome is 20/400.

Fortunately, such events are uncommon, and improved techniques for administering local anesthesia to the eye have some practitioners questioning whether they should occur at all. Others suggest it may be time for a new standard of care so local ocular anesthesia is no longer the potentially riskiest part of routine cataract surgery.

But is injectable anesthesia so risky? While it’s true that regional injection is implicated in 87% of all anesthesia claims against OMIC insureds, this is to be expected given that it is the most common method of anesthesia used in ophthalmic surgery. A review of 598 closed and 218 open OMIC claims showed that over a 10-year period only 31 claims were filed because of complications from all types of ophthalmic anesthesia. Compare this to cataract surgery, which accounts for one-third of OMIC claims, or to retinal cases, which make up 17% of the total.

Reported complications following injectable anesthesia include needle perforation, orbital hemorrhage, central retinal artery occlusion, central retinal vein occlusion, optic atrophy and diplopia. Needle perforation of the globe is the most common complication, accounting for 19 of the 53 claims related to ophthalmic anesthesia in this review, 31 of which are OMIC and 22 non-OMIC. The clinical outcomes of these 19 needle perforation cases reveal that most were associated with a poor visual outcome; of course, it should be recognized that patients with a good visual outcome are less likely to file a claim in the first place. Seven of these cases occurred during the administration of peribulbar anesthesia and 12 during retrobulbar anesthesia. Patients who had a perforation from a peribulbar injection tended to do better than those whose perforation resulted from a retrobulbar injection.

In 12 cases, the perforation was recognized prior to surgery, the case was canceled and the patient was referred to a retinal specialist. These cases were analyzed separately to see if this had any affect on visual outcome, but there was no indication among this small group of patients that their outcomes were any better than those in whom the perforation was not recognized until postoperatively.

Three of the 19 needle perforation cases closed without payment; six settled for an average indemnity of $145,000; two non-OMIC cases resulted in plaintiff verdicts averaging $1.9 million; four closed with defense verdicts; and four remain open. Closer examination reveals final vision better than 20/100 in all three cases closed without payment and weak causation arguments or limited damages in the four defense verdicts. Pre-trial settlements and plaintiff verdicts were more likely when the patient suffered decreased vision or lost visual field as a result of the needle perforation.

Poor Outcomes Follow Retrobulbar Blocks

Other complications related to injection of local anesthesia in this review included six cases of retrobulbar hemorrhage, five cases of optic neuropathy, five cases of vascular occlusion, six deaths, two seizures and three miscellaneous complaints. Of the six patients suffering retrobulbar hemorrhages, all had retrobulbar blocks and five had poor visual outcomes (< 20/200). One patient was on Coumadin at the time of surgery; another was a hemophiliac who did not receive factor 8 before or after surgery and suffered a delayed hemorrhage after leaving the surgery center. In several cases, a lateral canthotomy was performed following the hemorrhage and in another the orbital hemorrhage was drained, but despite these measures, there was a poor visual outcome in all cases. Four of the six cases had closed at the time of this review, three without payment and the fourth settled for an undisclosed amount.

All five cases of optic neuropathy followed retrobulbar anesthesia and all had poor visual outcomes. Four of the cases closed with defense verdicts and one non-OMIC case closed with a plaintiff verdict of more than $500,000. Four of the five cases of diagnosed or presumed central retinal artery occlusion following retrobulbar injection had poor visual results. One of these closed with a plaintiff verdict for $225,000 and three closed without payment. Both seizure cases were canceled and closed without payment as the patients suffered no residual damage. The three miscellaneous complications following retrobulbar injection included a serious stroke, diplopia and persistent facial numbness. Two of the cases closed without payment; the other remains open.

In almost every instance of death following local anesthesia injection, the patient was seriously ill at the time of the procedure: a post-cardiac transplant patient, a uremic patient on dialysis, an alcoholic patient with liver failure, and two patients with poorly controlled diabetes. Cardiopulmonary arrest was the stated cause of death in five of the six cases. One patient who had received large amounts of antihypertensives to treat elevated blood pressure during the procedure became very hypotensive following the procedure and arrested. The uremic patient who died at home later that night was found to have elevated serum potassium. Four of the six cases were settled and two closed without payment.

The anesthesiologist was the primary target in most of these cases; however, the ophthalmic surgeon was involved in some of the settlements as well.

Other Techniques Present Risks Too

These findings remind us that claims against ophthalmologists also arise from the use of general and topical anesthesia. Of five cases involving general anesthesia, two patients died following the anesthetic, one suffered an expulsive hemorrhage after gagging on the endotracheal tube, another suffered a transient ischemic attack, and the fifth developed adult respiratory distress syndrome. The last two patients fully recovered and their cases closed without indemnity while the expulsive hemorrhage case was settled with the anesthesiologist for $135,000. In the two cases involving topical anesthesia, the patients experienced suprachoroidal hemorrhages and had poor visual outcomes. A defense verdict was delivered in one case and the other settled for $150,000.

In summary, OMIC has experienced 31 cases related to ophthalmic anesthesia over the past 10 years. This represents only about 4% of all claims and is a small part of the 33% of claims related to cataract surgery, indicating that ophthalmic anesthesia needn’t be considered the riskiest part of cataract surgery. No standard of care exists with respect to choice of anesthetic technique and serious complications can occur with each method of anesthesia. The surgeon should choose the technique best suited to the needs of the patient and most appropriate for the procedure.

Risk Reduction Guidelines for Ophthalmic Anesthesia

Stay alert to symptoms (sudden loss of vision or severe pain) and signs of needle perforation (hypotony, decreased red reflex, vitreous hemorrhage, hyphema or increased intraocular pressure) when administering injections around the eye.
If a perforation is recognized, abort the procedure, advise the patient of the complication and obtain an immediate retinal consult. A patient whose complication is recognized and treated early may have a better final outcome.
Consider general, topical or blunt cannula local infiltration anesthesia in high-risk patients, i.e., high myopes, patients with prior scleral buckling or patients with a bleeding tendency, but remember these alternatives carry their own risks.
The ophthalmic surgeon may be held liable for damages even if an anesthesiologist or CRNA administers the anesthesia. Ascertain and document that the anesthesiologist or CRNA is adequately trained to give ocular injections and alert them to any risk factors that might increase the possibility of needle perforation such as increased axial length, previous scleral buckle or posterior staphyloma.
Consult with the patient’s primary care physician in cases where the severity of a pre-existing condition or illness could increase the patient’s anesthesia risks and document that you did so.
Needle perforation is a rare but potentially serious complication of local anesthesia injection and may be explained as such in the informed consent discussion or document.