Introduction

Hippocrates, the father of medicine, stated, "in every movement of the body, whenever one begins to endure pain, it will be relieved by rest". The medical profession has, over the centuries, continued to prescribe bed rest for a large number of conditions; in the last 75 years or so, the classical disorders calling for relative immobility have been myocardial infarction and back pain. However, since the 1940s the dangers of bed rest have become increasingly obvious - they include deep vein thrombosis, bedsores, osteoporosis and pneumonia. Unfortunately, too many patients are still content to prescribe bed rest for themselves. Now, three Australian investigators have analyzed studies published between 1966 and 1998 in which the potential benefits of bed rest have been examined as therapeutic or preventative modalities.

Method

Medline and the Cochran Library were searched for clinical studies of randomized groups in which the only main difference was the amount of bed rest prescribed. Groups had otherwise to be in the same environment (e.g., hospital or home) and receive the same treatments other than bed rest. The therapeutic use of bed rest was classified as either prophylactic treatment after a medical procedure, or primary treatment for a condition. No pooled analyses were attempted because of the variation in the indications and in the duration of bed rest prescribed, even within the same indication.

Results

The strict inclusion/exclusion criteria used limited the analysis to 39 randomized controlled trials, which examined the effects of bed rest on over 5000 patients with 15 different disorders.

The results of each study were examined with respect to the variation of the effects of bed rest - beneficial or harmful - and the corresponding odds ratio was calculated, together with 95% confidence intervals to permit determination of statistical significance.

In 24 trials of bed rest prescribed to follow various medical procedures, 7 outcomes were better with bed rest, but none significantly so, while 26 outcomes were worse after bed rest - 9 significantly so. In the case of rest after lumbar puncture, spinal anesthesia, and radiculography, the outcomes comprising headache, nausea, vomiting, or dizziness were significantly worse in 4 instances.

Of more interest to older patients, studies of rest after cardiac catheterization compared a variety of times of ambulation, from 2 to 6 hours after the procedure. Ill effects - chiefly bleeding and hematomas - indicated that 2.5 hours rest is sufficient after catheterization with 5-F or 6-F catheters, while 4 hours is sufficient after the use of 7- F catheters.

In the 15 studies of the use of bed rest as a primary treatment, 6 outcomes were better with bed rest, but none significantly so, while 25 outcomes were worse, 9 significantly so. The indications of interest for older patients included acute low back pain and uncomplicated myocardial infarction. In treating low back pain, early mobilization (<2 days rest) was superior to bed rest (2 to 7 days) in 8 of 10 outcome measures from 5 randomized studies. In the 4 studies that evaluated early ambulation in myocardial infarction, there were 3 negative and 2 positive outcomes, but none of them was statistically significant, except for increased venous thrombosis in the longer bed rest group of a 3-day vs. 7-day study.

Comment

This analysis provided no evidence that bed rest as a form of management in a wide range of settings had any advantage over early ambulation, and there were indications that it might actually delay recovery or even cause harm. The strict selection criteria used by the investigators meant that some interesting studies had to be excluded. For instance, a trial that showed a benefit of bed rest after intra-articular steroid administration in knee synovitis compared in-patients with patients sent home after the procedure. In another trial, done in the military, bed rest for acute low back pain proved advantageous, largely because army drill sergeants enforced early ambulation. It makes the useful point that pushing patients beyond their normal level of exercise is counterproductive.

Alarmingly, the authors report that as late as 1998 protocols used in spinal puncture procedures showed that more than 80% of neurological units in the United Kingdom insisted on bed rest. It is likely that excessive bed rest is still being prescribed in many hospitals after cardiac catheterization and myocardial infarction, as well as for acute low back pain treated at home. The situation is perhaps less serious in the USA - current practice dictates only 8 -12 hours' bed rest after myocardial infarction, with ambulation starting by day 3. For many US patients, medical insurance payment schemes have forced shorter hospitalization periods; similar effects are occurring in other countries. Perhaps this trend carries the hidden benefit of hastening ambulation.

It may be concluded that, in general, early ambulation should be practiced wherever possible, whatever the age of the patient, within that patient's capabilities and normal limits. Not to do so is running the risk of serious adverse effects of bed rest.