SUMMARIES FOR PATIENTS

Excess Body Weight and Outcomes of Acute Lung Injury Requiring Mechanical Ventilation

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The summary below is from the full report titled "Excess Body Weight Is Not Independently Associated with Outcome in Mechanically Ventilated Patients with Acute Lung Injury." It is in the 2 March 2004 issue of Annals of Internal Medicine (volume 140, pages 338-345). The authors are J.M. O'Brien Jr., C.H. Welsh, R.H. Fish, M. Ancukiewicz, and A.M. Kramer, for the National Heart, Lung, and Blood Institute Acute Respiratory Distress Syndrome Network.

What is the problem and what is known about it so far?

Many U.S. adults weigh more than they should. Being overweight puts people at risk for poor health and contributes to many common chronic diseases, such as high blood pressure and diabetes. However, little is known about the outcomes of overweight people during serious illnesses requiring treatment in an intensive care unit. Acute lung injury is a condition where the lungs become inflamed and people develop difficulty breathing. People with acute lung injury often need intensive care unit treatment with mechanical ventilation. Mechanical ventilation involves putting a tube down a person's throat and connecting it to a machine that breathes for the patient. Some doctors suspect that people who are overweight have a more difficult time recovering from acute lung injury than patients who are of normal weight.

Why did the researchers do this particular study?

To find out if overweight patients with acute lung injury requiring mechanical ventilation do worse than normal-weight patients with the same condition.

Who was studied?

902 patients who participated in one of several previous studies about the treatment of acute lung injury.

How was the study done?

The researchers compared the outcomes of patients who were normal weight, overweight, and obese (severely overweight). The outcomes they focused on were death and time until patients were able to breathe on their own without the mechanical ventilation.

What did the researchers find?

Overweight and obese patients had outcomes similar to those of normal-weight patients.

What were the limitations of the study?

This study focuses on a single condition. Excess body weight could have a negative impact on other conditions requiring intensive care unit treatment.

What are the implications of the study?

Doctors should treat acute lung injury similarly in normal-weight and overweight or obese patients. They should also expect similar outcomes regardless of patient body size.