American Academy of Ophthalmology Web Site: www.aao.org
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September 2007

 
Clinical Update: Eye on Eye Medicine, Part Five
Preempting the Pain From Eye Surgery
By Pat Phillips, Contributing Writer
 
 

Ophthalmic surgery stands tall in cutting-edge technology and minimally invasive techniques. But it may fall short in the optimal management of pain. “We’re not sophisticated in our training and in evaluating and treating patients who have ocular pain associated with surgery,” said C. Robert Bernardino, MD, associate professor of ophthalmology and director of residency programs at Yale University. “We need to realize we can do better,” he said.

Surgeons should become proactive in thinking about pain management issues before ever entering the operating suite, according to Dr. Bernardino. “Surgeons need to be aware of the patient’s emotional, mental and psychological state that keys into surgery.” He finds that young men are the most difficult surgical patients because they do not want to admit anxiety about pain, and instead just grin and bear it. “No patient needs to bite the bullet,” he said.

John D. Ng, MD, associate professor of ophthalmology, otolaryngology, and head and neck surgery at Oregon Health & Science University in Portland, agreed. “We need to raise our level of consciousness about assessing patient pain, preoperatively and postoperatively. We need to become more sensitive to pain, not undertreat it.”


Thresholds for Pain and Relief

Pain specialists agree that tolerance of pain varies from patient to patient, and that the spectrum of pain perception is very wide, ranging from annoying to troublesome to agonizing. Pain can be complex, affecting mental and physical well-being and quality of life. For some patients, the prospect of both surgery and anesthesia can be anxiety-producing and depressing.

Patient profile. Dr. Bernardino stresses the importance of patient evaluation prior to surgery. “It’s important to understand who may be at risk for experiencing pain, to consider pretreatment options to minimize it and then to improve postoperative pain control.” He suggests asking patients open-ended questions that will help the surgeon understand the pain risk. What types of surgical experiences has the patient already had? Were there any problems with pain? How was it managed?

“If you prescreen patients for fear and anxiety issues related to surgery and then pretreat them it will make their overall surgical course much better,” Dr. Bernardino said. “If patients are anxious, they’re going to be more attuned to any pain they may experience and be more difficult to treat,” he said.

Dr. Ng also typically asks patients about anxiety and fear prior to surgery. He finds it is useful to learn whether patients become anxious when they visit the dentist. Does local anesthesia work well in the dentist’s office? Do they need to have multiple injections to minimize pain at a dental visit?

“Prior to surgery, if a patient is bothered by the surgeon checking pressures or by irrigation of the canalicular system, then they’re not going to be able to stay still for a local anesthetic procedure in the office,” Dr. Ng said. He uses the “Integrated Pain Rating Scale” as a way to quantify pain. This numerical scale goes from zero to 10, with zero meaning no pain and 10 indicating the worst possible pain. The scale also is color-coded from blue, or no pain, through a rainbow spectrum to deep red, reflecting excruciating pain.


Anesthetic Applications

Surgeons are using traditional agents in new ways. Lidocaine, a fast-acting, short-duration anesthetic that confers good pain control, can be mixed with a long-duration agent for postoperative pain management, according to Dr. Bernardino. Lidocaine is effective for about two hours while a more lasting agent like bupivacaine is effective for about six to eight hours. “It’s better to mix a short-acting drug and a long-acting drug instead of giving two injections,” he said.

Frequently, lidocaine is buffered with bicarbonate at the point of injection to minimize pain, he added, and the use of hyaluronidase speeds onset and allows the anesthetic to penetrate and diffuse faster. Epinephrine also increases efficacy and limits bleeding.

Dr. Ng just completed a randomized, double-blind trial comparing lidocaine to the local anesthetic articaine, which is primarily used in dentistry. The 30 patients were unaware of which side of their face in symmetrical oculoplastic surgery was receiving articaine and which side lidocaine. “We found there was a statistically significant difference—there was less pain with articaine compared with lidocaine.” He noted the two anesthetics have the same pH, but articaine may have a higher affinity for receptors and appears to bind faster, resulting in less pain on injection.

Continuous infusion. Orbital catheters are coming into their own to give either continuous infusion or boluses of anesthetic postoperatively, according to Dr. Ng. “I administer boluses postoperatively in the clinic for enucleation patients where I can monitor them postinjection.” Other physicians sometimes send patients home with intraoperatively placed catheters and pumps for continuous infusion of local anesthetic.


Office vs. Hospital Setting

Patient anxiety may play a role in choosing between an office setting or a hospital suite for a procedure.

The calm, confident patient. Some patients choose for themselves the office, according to Dr. Ng. “These patients tend to have a higher tolerance for little or no sedation, less anxiety about the procedure, more tolerance for local anesthesia and fewer comorbidities than patients who are more appropriate for the hospital setting,” he said.

The trend is toward more surgical procedures in the office setting, according to Dr. Bernardino, who cites the evolution of cataract surgery. “It started out as an in-patient procedure, with patients hospitalized for days, and now we’ve migrated to millimeter incisions, fast surgical techniques, minimal use of sutures and speed in wound closure.”

Dr. Bernardino noted that as an oculoplastic surgeon, he performs up to 30 percent of his procedures in the office setting, using a mild preop sedative that does not make the use of anesthesia any more difficult or dangerous. He finds that mild, oral sedatives minimize pain and make patients more comfortable.

The cautious, complex patient. Patients who express significant fear about a forthcoming procedure and who say they want heavier sedation to keep them calm and pain-free are candidates for the hospital suite, according to Dr. Bernardino. And there is generally agreement among surgeons that patients with comorbidities, such as diabetes, hypertension and heart disease, who may be at risk for oculocardiac reflex, should have surgeries in an acute-care setting, where they can be monitored.

Infection control is another indication for the hospital setting, according to Dr. Bernardino. If a procedure requires a high level of sterility, the hospital operating suite is best.

The invasiveness and duration of the procedure and the type of anesthesia are other factors to consider in selecting the setting, according to Dr. Ng. “When general anesthesia or significant sedation is planned, there is a longer recovery and more demands on the physiologic system.” Also, he said, “the more invasive the procedure, the longer the duration, the more risk there is and more postoperative pain to manage. If there is risk of injury to the globe and the orbital structures, including retrobulbar hemorrhage, the surgery may have to be aborted. That’s very significant in patients with open globes where expulsive hemorrhage can occur.”

OR communication. The goals of anesthesia are to anesthetize the tissue in a safe manner, make the patient comfortable and, if needed, fully immobilize the eye, said Dr. Bernardino, and both preop and postop cooperation between the ocular surgeon and the anesthesiologist are important. “There needs to be synergy between the ophthalmologist and the anesthesiologist to provide optimal care. But the burden is on the ophthalmologist to make sure the patient is safe for surgery on a case-by-case basis,” he said.

The anesthesiologist is also essential to intervene if there is a complication, such as cardiac arrhythmia, so that the surgeon can concentrate on the surgery, according to Dr. Ng.


Pain Management Education

Organized medicine is paying more attention to residency training in pain management. And according to the Pain and Policy Studies Group at the University of Wisconsin, five states—California, Michigan, Oregon, Tennessee and West Virginia—now require continuing education in pain management. Another five—Florida, New Mexico, Ohio, Rhode Island and Texas—explicitly encourage pain management education (www.painpolicy.wisc.edu/index.htm). The Joint Commission on Accreditation of Hospitals stipulates that patients be methodically addressed with direct questions about pain control, and that surgeons receive training in conscious sedation if they operate without an anesthesiologist.

Still, there is not yet a widely standardized curriculum on pain management, Dr. Bernardino said. “Residency training in pain management needs to be improved and expanded. Residents learn by what they see, otherwise they don’t learn it.”
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Drs. Bernardino and Ng report no financial interests related to this story.
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At the Annual Meeting, Dr. Bernardino will conduct a course titled “Office-Based Surgery That Is Painless for Both Patient and Surgeon: Pearls on Anesthesia, Pain, Nausea and Anxiety.” The course (Event Code 415) is scheduled for Monday, Nov. 12, at 3:15 p.m. and will confer a pain management credit.