Post Surgery Obesity Paradox

Obese patients protected against respiratory complications after surgery

(RxWiki News) Obese patients are at greater risk for developing diabetes, high blood pressure, erectile dysfunction and heart disease. There is one condition it seems protective against.

A recent study indicates that obese patients who develop respiratory insufficiency and adult respiratory distress syndrome (RI/ARDS) after surgery are less likely to die.

"Extra fat seems to prevent breathing complications after surgery."

Lead study author, Stavros G. Memtsoudis, M.D., Ph.D., an anesthesiologist at Hospital for Special Surgery reports that even though physicians assume that obese patients have worse outcomes during and after surgery, this study indicates that isn't the case with regards to RI/ARDS.

Obesity may actually be protective against those respiratory conditions.

Researchers offer three different theories explaining why obesity is possibly protective against mortality in patients with RI/ARDS. First, they may have a better nutritional status to help them get through an acute illness.

Second, their fatty tissue may act as a repository for inflammatory proteins, keeping them out of the circulatory system.

Dr. Memtsoudis explains that this may slow down the inflammatory process. Third, doctors may be more vigilant with obese patients since their surgical complications tend to be more dramatic.

If the reason is due to vigilance, Dr. Memtsoudis recommends that hospitals encourage the same standard of care to be given to all patients. This may help reduce the incidence of RI/ARDS in hospitals.

If the reason is due to fat acting as a repository for inflammatory proteins, more research can lead to a better understanding of that mechanism, allowing researchers to possibly develop ways to extend that protection to all patients.

For this study, between 1998 and 2008, the researchers used a large national database to identify patients who underwent common surgical procedures known to have a high risk for RI/ARDS. Around 9 million patients, 5 percent being obese, met the criteria.

Obese patients had an incidence of RI/ARDS 1.82 percent of the time while the non-obese patients incidence was 2.01 percent. Of those with respiratory problems, hospital mortality rates were significantly lower in obese patients at 5.45 percent compared to 18.72 percent in the non-obese patients.

Additionally, the need for mechanical ventilation, required for the most severe cases of RI/ARDS, was lower in obese patients at 50 percent compared to the normal weight patients at 55 percent. In the patients requiring intubation, mortality rates were also much lower in obese patients at 11 percent compared to 25 percent in the cohort group.

These findings are published online, before the print edition, by the Journal of Intensive Care Medicine.

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Review Date: 
July 11, 2011