Obesity lengthens time in OR and raises complication risk

In a national study of 10 common abdominal surgeries, operations on patients who were overweight or obese tended to take longer as the patient’s weight increased, as did the chances that they would develop serious complications.

“We saw a consistent increase in operative time as weight increased, increasing as much as 26% with the most obese patients,” said lead author, Dr. Christopher Childers, assistant professor of surgery at the University of Washington School of Medicine. “The complications ran the gamut, from wound infections to clots developing in the lungs to renal failure.”

The findings underscore the challenge that health systems face in caring for patients who are overweight and obese, Childers and coauthors noted. About 74% of American adults are overweight and nearly 43% are obese, according to the U.S. Centers for Disease Control and Prevention.

For surgeons who are, by and large, paid a fixed amount for performing a procedure, the findings suggest operations on these patients results in work that goes uncompensated, Childers said. 

“I worry this may influence surgical decision-making and may place patients at risk of not receiving the care they need and deserve,” he said.

The study was published online in the Journal of the American College of Surgeons. The senior author was Dr. Christopher Senkowski, professor of surgery at Florida International University in Miami.

In the study, the researchers reviewed the medical records of nearly 160,000 patients who had undergone 10 common abdominal operations.  These included relatively simple procedures such as a hernia repair and appendectomy, more complicated bowel and colon operations, and major operations that involve removal of all or part of the pancreas, duodenum, gallbladder and bile duct.

The patients were classified based on their body mass index (BMI). BMI is calculated from a patient’s height and weight. A man of average height, about 5 feet 9 inches, for example, who weighs between 126 and 168 pounds would have a BMI between 18.5 and 24. This is considered a healthy range. He would be considered overweight if he weighs over 169 pounds, a BMI of 25, and obese if he weighs over 203 pounds, a BMI of 30.

Obesity is divided into three classes: A man of average height would be considered to have Class 1 obesity with a weight of 203 pounds; Class 2 at 236 pounds; and Class 3 at 270 pounds. A weight of 338 pounds and above would be considered extreme obesity.

For a woman of average height, 5 feet 4 inches, a healthy weight is between 110 to about 144 pounds, she would be considered overweight at 145; Class 1 obese at 174 pounds; Class 2 at 204 pounds; Class 3 at 232 pounds; and extremely obese at and above 291 pounds.

The researchers’ analysis found that compared to the patients with a BMI in the healthy range, procedure times increased 5.6% when the patients were overweight, 10.6% with patients with Class 1 obesity, 14.7% with Class 2, 18.9% with Class 3, and 26.8% among those with extreme obesity.

A 26% increase in operative time might add about 15 minutes to a simple procedure like an appendectomy, Childers said, but for a complex surgery that typically takes about six hours, it could mean another hour on the operating table.

Complications also increased with patients’ weight. Compared to patients with a healthy weight, extremely obese patients had a more than twofold increased risk that their sutured wound would reopen, a more than threefold risk of developing a blood clot in the lung, and a more than fivefold increased risk of a deep wound infection.

Excess weight complicates surgeries in a variety of ways, Childers said: It makes it more difficult to see, reach and manipulate the tissues being operated on, and harder to bring tissues together for suturing.  

Heavier patients also are harder to get on and off the operating table, transfer from gurney to bed, and to get up and walking after surgery.

“Excess weight is also a huge burden on patients, who are more likely to have more complications and slower recovery, and to health system as a whole,” Childers said. 

Written by Michael McCarthy

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