By assessing electronic medical records (EMR) of 32,835 unique individuals from six Dallas-Fort Worth area hospitals, and noting abnormalities in temperature, heart rate, blood pressure, respiratory rate, and oxygen saturation within 24 hours of discharge, scholars determined that nearly 20 percent had one or more abnormalities, with elevated heart rate being the most common vital sign instability (affecting about 10 percent.) About 13 percent were readmitted or died, and individuals with three or more instabilities had a nearly four-fold increase in the odds of death.  

As hospital stays have shortened dramatically over the past 30 years, there is increasing concern that patients are being discharged before all vital signs have stabilized, putting them at risk of adverse events after discharge. However, no studies to date have examined the extent to which patients are discharged with unstable vital signs, and whether this practice is actually associated with higher post-discharge mortality and readmission rates, the researchers said. 

Researchers concluded that:

• Discharge guidelines should include objective vital sign criteria for judging stability on discharge to improve disposition planning and post-discharge patient safety.

• At a minimum, patients with one instability on discharge should be discharged with caution.

• Close outpatient follow-up and appropriate patient education about warning signs and symptoms that merit urgent medical attention may be warranted.

• Individuals with two or more instabilities should likely remain in the hospital for continued treatment and observation in the absence of extenuating circumstances.

• Though post-acute care facilities are frequent sites of post-discharge care for those discharged with vital sign instabilities, patients sent to these facilities had still higher rates of readmission and death, suggesting that an alternate site of discharge may have been more appropriate for a significant subset of these individuals.

"We found that nearly 1 in 5 hospitalized adults is discharged with one or more vital sign instabilities such as an elevated heart rate or low blood pressure," said lead author, Dr. Oanh Nguyen, Assistant Professor of Internal Medicine and Clinical Sciences at
UT Southwestern Medical Center
. "This finding is an important patient safety issue because patients who had vital sign abnormalities on the day of discharge had higher rates of hospital readmission and death within 30 days even after adjusting for many other risk factors."

"Our findings, that 'vital signs are still vital' have important implications for the development of national discharge guidelines to improve patient safety for the 35 million individuals being discharged from hospitals in the U.S. annually," said co-lead author, Dr. Anil Makam, Assistant Professor of Internal Medicine and Clinical Sciences.

"At a time when people are developing complicated, black box computerized algorithms to identify patients at high risk of readmission, our study highlights that the stability of vital signs, something doctors review with their own eyes every day, is a simple, clinically objective means of assessing readiness and safety for discharge. There's a good reason we call them vital signs," said senior author Dr. Ethan A. Halm, Chief of the William T. and Gay F. Solomon Division of General Internal Medicine, Chief of the Division of Outcomes and Health Services Research in the Department of Clinical Sciences at UT Southwestern, and Director of UT Southwestern's Center for Patient-Centered Outcomes Research. "It is important for clinicians to look at all of the vital signs in the 24 hours prior to discharge and not just the last set or the best ones in judging a patient's readiness for discharge."

The study appears in the Journal of General Internal Medicine.