August 2009

 

COVER FEATURE

 

challenging cataract cases

Cataract severity may determine anesthesia choices


by Michelle Dalton EyeWorld Contributing Editor

   

While topical anesthesia has its use, most surgeons prefer blocks for complex cataract cases

Anesthesia

A good general rule of thumb to follow when preparing an anesthesia regimen for a patient scheduled to undergo cataract surgery is that any patient who is a candidate for block anesthesia (peri- or retrobulbar) may also be a good candidate for topical anesthesia. Pre-determining in the office or in the surgical lane who is a good candidate for topical/intracameral or a block can ease both surgeon and patient concerns about surgery, according to the experts.

Overly anxious patients may be more difficult than the obvious complex cataract cases, said James P. Gills, M.D., Tarpon Springs, Fla. “The concern with these patients is how they may react during the case, which could lead to complications,” he said, citing potential vitreous loss, increased risk of cystoid macular edema, or even lens malpositioning, resulting from a patient who cannot lie still on the table. “Using topical anesthesia for cataract surgery is much simpler for the patient, but what should be a straightforward case could become complicated if the patient becomes extremely anxious,” he said.

EyeWorld asked leading cataract surgeons which regimens they prefer, which combinations are best in their hands, and when topical blocks or general anesthesia is best for all parties.

Overall anesthesia strategies

Topical anesthesia use has certainly increased in recent years, but many surgeons still use blocks or general anesthesia. The more complex a case is, the more likely surgeons are to choose a block.

For instance, if patients are unable to look at the indirect ophthalmoscope light, or can’t hold steady fixation, “they are probably not a good candidate for topical anesthesia,” said Lisa B. Arbisser, M.D., adjunct clinical associate professor, John A. Moran Eye Center, University of Utah, Salt Lake City. “People who have chronic pain or are alcoholics will just eat up whatever anesthesia you give them and dosing must be adjusted accordingly. I like to be sure who that may be before the day of surgery.” In her practice, Dr. Arbisser gives about 75% of her patients topical, with the remaining 25% receiving a peribulbar injection. “I don’t use topical anesthesia without using intracameral as well,” she said.

At Island Eye Surgicenter, Carle Place, N.Y., “we had a pre-op regimen of various drops, consisting of lidocaine solution, antibiotic, NSAID, and dilating drops requiring instillation of 20 drops before surgery. It was quite burdensome for the patients and the staff,” said Stanley J. Berke, M.D., associate clinical professor of ophthalmology and visual sciences, Albert Einstein College of Medicine, New York, and chief, Glaucoma Service, Nassau University Medical Center, New York. These days, his practice mixes the same drops with lidocaine gel. (See sidebar for various anesthesia protocols.) “With one application, we achieve excellent anesthesia as well as the best dilation. The lidocaine gel mixture provides better topical anesthesia than just topical tetracaine or lidocaine drops,” Dr. Berke said. Thomas L. Beardsley, M.D., Asheville, N.C., said about 95% of his patients receive topical, “and 5% receive a block in addition to topical and intracameral lidocaine. For routine cases, we use a light sedation (usually midazolam and alfenta). This combination has a rapid onset and rapid elimination.”

Typically, Dr. Beardsley said his topical regimen is comprised of lidocaine jelly 2%, augmented with intraocular buffered 0.75% lidocaine (preservative-free) with 1:4000 epinephrine (“epi-Shugarcaine”). A patient’s command of English and predicted surgical complexity aids Kevin M. Miller, M.D., Kolokotrones Professor of Clinical Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, in his decision to use topical, injection or general anesthesia, with about 90% of his patients receiving topical.

“For those who will receive an orbital injection I use a 50-50 combination of 2% lidocaine and epinephrine and 0.75% Marcaine (bupivacaine),” he said. “We inject it behind the eye and the combination generally helps the case go quickly. We’ll also use 2% carbocaine for the facial block.”

Carbocaine was found years ago to be a better blocking agent for motor nerves, and lidocaine a better agent for sensory nerves, Dr. Miller said. “For the 90% who will undergo topical anesthesia surgery, I apply 0.75% Marcaine to the ocular surface and inject 1% non-preserved lidocaine,” he said.

Dr. Gills administers diazepam preoperatively, and a combination of topical proparacaine and Xylocaine 2% jelly in the surgical suite, and once the incision is made, patients receive preservative-free 1% Xylocaine (0.5cc) intracamerally.

For Arthur Cummings, F.R.C.S.Ed., medical director, Wellington Eye Clinic, Dublin, Ireland, 90% of his cases are done under topical anesthesia, with a supplementary small subconjunctival injection of local anaesthetic under the superior bulbar conjunctiva (at 12h00) and a small amount (1cc) of sub-Tenon’s anaesthesia in the infero-medial quadrant.

“To date, I’ve never needed to top up during a procedure when using the 1cc Sub-Tenon’s supplement,” he said. “The small subconjunctival injection into the superior bulbar conjunctiva seems to totally settle the patient and remove any possible area that may still be sensitive after the sub-Tenons is given.”

He will instill topical proxymethacaine (two drops, 5 minutes apart) just before surgery, and use a 0.2 cc injection of 50% Marcaine/50% lignocaine into the superior bulbar conjunctiva. Next, Dr. Cummings will inject 1 cc sub-Tenon’s anaesthesia with the canula placed into a small conjunctival incision made in the inferior-medial quadrant after small sub-conjunctival injection. “With this anaesthetic approach, the patient is usually 100% comfortable and feels absolutely nothing. The long-acting Marcaine provides post-operative pain relief too,” he said.

Younger men can be further aided with intracameral injections, Dr. Miller said. “For whatever reason, these patients are more sensitive to intraocular pressure fluctuations. If a patient has had a vitrectomy or is really myopic, those are the ones who really benefit from intracameral supplementation. Most of the others probably don’t need it,” he said.

Using intracameral injections “makes all the sense in the world— you’re already inside the eye,” Dr. Cummings said, although he has yet to use that technique.

When blocks make sense

Particularly challenging cases should are probably best attempted under topical, said Brian Little, F.R.C.Ophth., consultant ophthalmologist and cataract service training director, Moorfields Eye Hospital, London.

“The risk of ocular discomfort under prolonged and complex surgery is quite high and generally counterproductive to a relaxed surgical environment,” he said. For those patients, he typically administers a single site peribulbar block of 5ml 2% lidocaine. Determining when to use topical and when to administer a block comes down to surgeon experience and personal comfort zone, as well as the level of concern about the case, Dr. Little said. Determining when to use topical and when to administer a block comes down to surgeon comfort, patient comfort and your level of concern about the case, Dr. Beardsley said. “If I anticipate problems outside of the norm or if the surgery is going to be prolonged, I want a deeper block going in,” Dr. Beardsley said. “When you’re using topical, you need to be in and out quickly.” The type of planned surgery may dictate which to use as well: iris manipulation, planned suturing of the IOL, or making incisions through the conjunctiva or sclera will necessitate a deeper level of anesthesia than topical alone can provide, Dr. Beardsley added. Dr. Berke agreed, saying the time for blocks is in situations where surgery is more complex. “There was a time when we first started doing topical over 10 years ago and I was trying to do topical on every case,” he said. “It’s possible to do it in the straightforward cases, even those combined cases with glaucoma, but I found if it’s a long case or when it becomes more complicated than expected, patients got uncomfortable and might start feeling the suture, or the vitrectomy. I’d rather they have a block.”

Because of regional prescribing tendencies, a large majority of the men Dr. Berke sees are on Flomax (tamsulosin, Boehringer Ingleheim), and as a result he has the anesthesiologists at his surgicenter block about 50% of his patients.

Dr. Gills added patients with Alzheimer’s or Alzheimer’s symptoms and those with Fuch’s dystrophy should be blocked as well. “It’s extremely important in Fuch’s patients to minimize movement,” he said.

In those cases where the centration of the multifocal IOL is crucial, Dr. Gills will opt for a block if the patient is unable to hold fixation for any reason or is overly anxious.

Added Dr. Arbisser: “Patients with Parkinson’s, or those who are extremely photophobic, or without good fixation, they’re are better off with a peribulbar block in my hands. We use no more than 5 mL, and only infraorbitally.”

In her hands, about 1% of the patients for whom topical has been chosen will be challenging. “Some brains are just wired differently, and the patient is absolutely unable to hold their eye steady despite instructions. They think they must follow the light as it appears to move. Surgical efficiency is really reduced in these patients, as you have to stay on your toes and constantly guide the patient verbally,” she said. Although the result can be satisfactory she opts for peribulbar injections in their second eye.

“My greatest concern is with the patients who continually move and don’t even realize it,” Dr. Gills agreed. Those patients “are blocked and may also require additional sedation.”

Dr. Arbisser also advocates using a block on patients with very shallow chambers, and advises using mannitol to help create more space in the anterior segment (1/4 gram/kg IV push as a bolus 15 min prior to surgery). “My peribulbar injection is 3-5 cc of lidocaine 2% with epinephrine, except that in the long complex cases such as subluxated cataracts the lidocaine is mixed with Marcaine 0.75% half and half to prolong the effect,” she said. Dr. Miller opts for blocks when he believes the surgery will be time-consuming. “Non-English speaking patients, those with posterior synechiae or a history of Flomax use, and those who don’t dilate well are significant candidates for a block,” he said. One pearl for administering a block: “When performing an orbital injection, don’t let the retrobulbar needle follow a curved path. Grab the lower lid with a wooden Q tip just below the inferior tarsal margin a third of the way in from the lateral canthus, and drag it down and out to expose the equator of the globe. Then enter through the skin with the retrobulbar needle immediately adjacent to the Q tip. This way you will be around the equator of the globe when you enter. You can still hit things, but you’re less likely to cause a retrobulbar hemorrhage if you an avoid changing directions while advancing the tip of a needle in the orbit,” he said. Dr. Berke is most concerned with Flomax when opting for a block over topical, but “Flomax-type drugs such as Hytrin (terazocin HCl; Abbott Laboratories) or uroxotrol can also be challenging,” he said. Couple the prostate medication with a light colored iris, and the patient is much more likely to have floppy iris syndrome, he said. “If they are on Flomax, and have blue or green eyes, those are the patients most likely to have full-blown IFIS, especially if they don’t dilate well,” he said. Patients with pseudoexfoliation are also better served by blocks, Dr. Berke said. “They tend to dilate poorly and have weak zonules, making them prone to more complicated surgery, possibly involving vitreous loss.”

When to use general anesthesia

Although much more uncommon these days, “there is a role for general anesthesia,” Dr. Berke said. He cited pediatric patients or those who are mentally impaired and incapable of cooperation. Erring on the side of caution, Dr. Cummings opts for general anesthesia if he’s expecting problems or in monocular patients. “It creates one less thing to worry about and it removes the anxious patient from the equation. The patient would normally be aware that it is their only eye or that it is expected to be an unusually difficult procedure,” he said. Topical anesthesia is “just as good as general anesthesia from the surgeon’s point of view, but when really complex cases are being done on only eyes, the patient themselves are usually very anxious and this makes the whole event more tense and error prone,” he said. Monocular patients are the “one group that tends to change the general rules of anesthesia,” Dr. Miller said. In all likelihood, “whatever caused them to go blind in the first eye is likely to be a comorbidity in the remaining good eye. This group receives more general anesthesia than any other group in my practice; only a very small percentage undergo injection.”

Planning ahead

Talking to the patient and keeping them calm—or “vocal local”—is another method used to help ensure the cataract surgery goes smoothly and quickly, Drs. Arbisser and Gills both said. As soon as he notices the patient is becoming agitated on the table, Dr. Gills will bring in additional personnel to verbally try and calm the patient. “I’ll block the patient on the table if nothing seems to be working and if they really can’t hold still,” he said. “Maybe 10-20% aren’t aware they’re moving, which turns an uncomplicated surgery into a very complex one.”

Dr. Arbisser said vocal-local is especially necessary if there is a complication. “I advocate the in-suite personnel have a kind of fire drill we call ‘code V’ periodically. If there’s a need for vitrectomy they are prepared and there is easy communication that won’t upset the patient,” she added.

Dr. Berke recommended scheduling more complex surgeries towards the end of the day. “Red flags for me are floppy iris and pseudoexfoliation,” he said. “For me, scheduling these later is less stressful and the day runs more smoothly doing the more straightforward cases first.” Other potentials that would indicate a more complex surgery requiring a block instead of topical include previous vitrectomy surgery, blepharospasm, and photophobia, he said. Complex cases require “meticulous planning for any special device or instrument requirements as well as careful planning of a primary surgical strategy with particular attention to machine settings and power modulation,” Dr. Little added. In combined phaco/trabeculectomy surgery, Dr. Berke prefers to use peribulbar block, although it can be done with topical and sub-tenons lidocaine. “You can perform endolaser cyclophotocoagulation (ECP) alone or combined with phaco using intracameral lidocaine or with a block. I recommend instilling intracameral lidocaine at the beginning of the case, and then again after the IOL is inserted prior to performing ECP,” he said. The bottom line? “If you’re uncomfortable with the thought of using topical, or you think the patient will be uncomfortable or uncooperative, then use a block,” Dr. Beardsley said.

Editor’s note: Drs. Gills, Arbisser, Berke, Beardsley, Miller, Cummings, and Little have no financial interests related to their comments.

Contact information:

Arbisser: 563-323-2020, drlisa@arbisser.com
Beardsley: 828-258-1586, tbeardsley@ashevilleeye.newsouth.net
Berke: 516-593-7709, sberke@ocli.net
Cummings: +353 1 2930470, abc@wellingtoneyeclinic.com
Gills: 727-938-2020, jgills@stlukeseye.com
Little: brianlittle@blueyonder.co.uk
Miller: 310-206-9951, kmiller@ucla.edu

Cataract severity and anesthesia choices Cataract severity and anesthesia choices
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