Detection of Endotoxemia by the Limulus Test in Patients with Indwelling Urinary Catheters

Abstract
Limulus tests were performed on sera from 39 hospitalized patients with indwelling urethral catheters to determine the prevalence and significance of circulating endotoxin-like activity. Positive limulus tests were found in 17 of 24 catheterized patients (71 %) with gram-negative rod bacteriuria or candiduria. In addition, positive tests were found in three of 15 nonbacteriuric patients (20%), two of whom had documented or suspected infections outside the urinary tract. Positive tests were not associated with the severity of the patient's underlying disease, age, sex, antibiotic therapy, or prior surgery. There was no increased incidence of hypotensive episodes or evidence of thermoregulatory disturbances in patients on days in which positive limulus tests were detected. In addition, positive limulus tests were not associated with increased mortality. These results suggest that positive limulus tests may be found in many noncritically ill patients with indwelling urinary catheters and that a positive test need not be associated with a grave prognosis.