Study casts doubt on routine use of anesthesiologists in cataract surgery

Ophthalmologists may be able to safely cut back on having anesthesiologists or nurse anesthetists routinely at bedside during cataract surgery, which accounts for more than two million surgeries per year in the U.S., according to a study publishing Oct. 3 in JAMA Internal Medicine. 

A team of researchers from UC San Francisco examined Medicare claims for 36,652 patients who had cataract surgery in 2017 and found the use of anesthesia care was substantially higher for cataract surgery when compared to patients undergoing other elective, low-risk outpatient procedures—such as cardiac catheterization or screening colonoscopy. However, they found that these patients experienced fewer systemic complications—such as myocardial infarction or stroke—than did patients undergoing the other low-risk procedures.  These results held true even in cases where anesthesia experts were not present for the cataract surgery, suggesting that for many cataract patients, it may be reasonable to consider doing the procedure without routine anesthesia support.

“It’s important to note we only looked at systemic complications and not ophthalmologic outcomes from the procedure,” noted senior study author Catherine Chen, MD, MPH, UCSF associate professor in  Anesthesia and Perioperative Care and researcher at the Philip R. Lee Institute for Health Policy Studies. “We are evaluating those next, but it would be premature to say we should change practice now based on this study. Hopefully we can get a conversation going, though.” 

Some type of anesthetic and possibly sedation is needed for cataract surgery, Chen noted, but the question is who should be present for administration and intraoperative monitoring of these patients. In the past, cataract surgery carried a much higher risk of complications, which helps explain the historic and legacy use of anesthesiologists and/or certified registered nurse anesthetists (CRNA). 

 “The risk of the procedure itself used to require general anesthesia with paralysis and inpatient admission. Over time, ophthalmologists improved their technique so it [cataract surgery] is much safer and can be done on an outpatient basis,” said Chen. “Often the patient just needs a topical anesthetic such as numbing drops in the eyeball, and, at UCSF anyway, a little fentanyl and midazolam, which are agents a sedation nurse can administer safely.”

A Question of Resources

The study found that, for cataract surgery, 90% of U.S. Medicare patients have an anesthesia provider at the bedside compared to a range of <1% to 70% at bedside for other low-risk elective procedures. In contrast, fewer cataract surgery patients experienced systemic complications within seven days (7.7%) than patients undergoing other low-risk procedures (range, 13% to 52%).  

Approximately 6% of ophthalmologists never used anesthesia providers, 77% always used anesthesia providers, and 17% used them for only a subset of patients. Patients of those ophthalmologists who never used anesthesia providers had a 7.4% rate of systemic complications. 

There is no specific guidance from professional associations on whether to include an anesthesia expert during cataract surgery, but other countries do not routinely use them, to no ill effect, Chen noted. 

With U.S. anesthesiologists being asked to staff an increasing number of non-OR procedures, such as endoscopic or interventional radiology procedures where patients tend to be much sicker and the procedure potentially more invasive, there often aren’t enough of these specialists go around, Chen said. 

“Add to this a general shortage of anesthesiologists since COVID, and it’s clear we need to ensure staff resources are used efficiently,” said Chen.

In an upcoming study, Chen and her colleagues will look at both systemic and ophthalmologic outcomes stratified by whether patients received care from an anesthesia provider during cataract surgery. While the current study used a sample of 5% of Medicare claims, the upcoming study will use 20% of claims. 

“It’s certainly possible that by having an anesthesiologist there, the patients are calmer and possibly less likely to move, and so the ophthalmologic outcomes could be better—so we are working on those studies now,” Chen said. “Where I think where we could end up, when the results are in, is that instead of automatically defaulting to include an anesthesiologist, we stratify patients by risk so that their level of sedation and anesthesia support matches their likelihood of complications.”

Co-authors and funding: Please see paper for additional co-authors and funding disclosures.