Obese Patients Have More Postop Problems
Published: May 28, 2014
By Ed Susman , Contributing Writer, MedPage Today
BOSTON -- Morbidly obese individuals undergoing elective hip replacement surgery had a higher rate of postoperative complications and infections than patients in other weight classifications, researchers reported here.
Compared with normal weight patients, the morbidly obese -- defined as those with a body mass index of 40kg/m2 or more -- lost more blood during the procedure (P=0.001), spent a longer time in surgery (P=0.012), and were more likely to have postperative wound infections (P=0.036), said Kristina Denenkamp, PA, a new graduate of the Wagner College physician assistant program in Staten Island, N.Y.
"Based on our findings we recommend this group delay elective hip replacement surgery and undergo weight-loss counseling to help reduce unfavorable complications and the overall cost of a hospital stay," she said at her poster presentation at the annual meeting of the American Academy of Physician Assistants.
"We wanted patients to be evaluated for weight-loss counseling -- whether it be diet or bariatric surgery -- before they rush into the hip replacement surgery," Denenkamp told MedPage Today.
Denenkamp and her colleagues Kara Hoye, PA, and Alexander Saltzman, PA, performed a chart review of 464 patients who underwent a hip replacement procedure between January 2010 and November 2013 at Staten Island University Hospital. Importantly, Hoye told MedPage Today, "We found that normal weight patients who underwent hip replacement surgery had a significant (P=0.029) decrease in the risk of postoperative complications."
When calculating the length of surgery, they found that being normal weight was protective (P=0.032) compared with the entire cohort of patients. Being overweight increased the length of the procedure, but not enough to be significantly different (P=0.421), said Saltzman. He told MedPage Today that being clinically obese also increased the length of the procedure but, again, that failed to reach statistical significance (P=0.203). And being morbidly obese resulted in a trend to significance (P=0.078), he said.
Denenkamp noted that 46 of the 464 patients in the study – about 10% -- were characterized as morbidly obese. "We think the failure of this group to reach statistical significance for time in surgery was likely due to the small numbers of patients in this category."
The researchers found a similar pattern with blood loss -- the only group having significant differences in blood loss were the morbidly obese (P<0.001).
"Increased body weight has been recognized as a risk factor for many medical conditions," the researchers reported in their presentation. "For surgery patients, it has been associated with poor wound healing, increased length of surgery, deep vein thrombosis, and increased length of hospital stay."
Denenkamp said that because hip replacement surgery is usually an elective procedure, engaging patients in weight-loss counseling might be a way to prevent some of these complications. The researchers only suggested weight-loss counseling; the study did not determine if weight-loss counseling was provided or if it had any impact on outcomes, she said.
The goal of the research was to determine if there was a body mass index cutoff at which greater risk occurred.
"We found that normal weight appeared to be protective, but morbidly obese patients were at risk," Denenkamp said.
In the study, the research team included patients undergoing their first hip replacement due to degenerative joint disease, other arthritis conditions, or avascular necrosis. The researchers excluded from their analysis individuals under the age of 18, those who had experienced traumatic hip injury, those with a history of renal failure, patients undergoing bilateral hip replacement or who had previously undergone hip replacement surgery.
The study was undertaken by the researchers as a project while still students at Wagner. They have since graduated from the physician assistants' program.
The researchers had no relevant disclosures with industry.
Primary source: American Academy of Physician Assistants
Source reference: Denenkamp K, et al "Correlating body mass index to post-op complications" AAPA 2014; Abstract 449.