Perioperative Smoking Linked to Riskier Outcomes after THA

By: Peter Pollack

Poster presentation quantifies risks

Cigarette smoking has been linked to numerous health issues, but comparatively little research has been conducted into the link between perioperative smoking and complication after total hip arthroplasty (THA). Quantifying that effect is the goal of poster presentation P049, “Effect of Smoking on Postoperative Complications after Total Hip Arthroplasty: A Propensity Score Matched Analysis,” which is on display in Academy Hall C.

“Our goal is to give patients enough information so they have an educated view of associated risks when they go into the operating room,” explained Matthew D. Beal, MD, one of the study authors. “This research is one piece of the puzzle, looking at different risk factors to see which ones actually make a difference and measuring what impact they have, not only on outcomes, but that may negatively affect comorbid conditions.”

The research team reviewed data on 60,353 THA patients from the American College of Surgeons National Surgical Quality Improvement Program’s (ACS-NSQIP) database. Patients were excluded if they had undergone bilateral or concomitant procedures, had a diagnosis other than osteoarthritis, or were missing data. To eliminate differences in demographics, comorbid diseases, laboratory values, and operative factors between groups, the researchers used a propensity score to generate a 1:1 match, with an adjusted logistic regression used to generate adjusted odds ratios.

Overall, 12,588 patients met inclusion criteria, of whom 1,501 (11.9 percent) were smokers. After adjustment for differences between smoking and nonsmoking cohorts, the research team found that smokers were at increased risk of deep surgical site infection (0.6 percent vs. 0.1 percent), sepsis (0.8 percent vs. 0.3 percent), and readmission (4.0 percent vs. 2.7 percent). In addition, smokers were 3.3 times as likely to be readmitted and 1.8 times as likely to experience a surgical complication. The researchers noted no significant difference between cohorts in overall rates of medical complications and mortality.

“We found that smokers had a higher risk for perioperative complications,” explained David W. Manning, MD, one of the study’s authors. “They had more issues with delayed wound healing and infections—both superficial and deep—which is related to microvascular disease and the ability to heal a wound without compromise. This is similar to what has been documented elsewhere.

“We were surprised to find that some of the data didn’t look as bad as we’d probably expected,” he continued. “We didn’t see as many infections as we thought we might, and to be honest, less difference between cohorts in wound infection. It may be just an issue of power—if we’d had a larger cohort of patients, we may have seen a bigger difference. I think everybody understands that smokers probably have more perioperative issues; we just didn’t see as much as we thought we would.”

Secondhand impact
Dr. Manning suggests that second-hand smoke may be an additional and often overlooked issue.

“As physicians, the other part of the conversation is with the partner in the room—the family member or spouse,” he said. “It’s just as bad if they smoke right next to the patient. Ideally, neither the patient nor the family members should be smoking, and we like to encourage people to consider stopping together and trying to support each other.”

Dr. Manning advises that smokers quit “at least a couple of months” prior to surgery.

“Risk factors are additive,” he explained, “and smoking is a modifiable risk factor. It takes a few months after quitting for your lungs to recover a bit; to get your glucose levels back in order, etc. You definitely don’t want to put patients in a situation in which they’ve quit just the week before. The cilia function doesn’t recover that quickly and there’s still a lot of crud in the lungs. There’s an increased risk of aspiration and pneumonia and pulmonary infection. They need to be off the cigarettes for a certain period of time and ideally should remain off them until their wound is completely healed.

“Many patients will tell you that hip arthroplasty is a life-changing event, and they’re going to quit and stay off the cigarettes for good. They may do that for a little while, but the reality is that many of them end up starting to smoke again, just because they’re around it all the time.”                          

Drs. Beal’s and Manning’s coauthors include Shawn Sahota, MD, and Francis Lovecchio, BA.