Among inpatients with cancer who have neutropenic fever, delaying antibiotic treatment past 60 minutes from the time of fever detection may not reduce the short-term chance of overall survival, according to a new study published by Villars et al in the American Journal of Medical Quality.
Background
Neutropenia—a condition that develops in more than 80% of patients who receive chemotherapy for blood cancer—is known to occur because chemotherapy may be destructive to neutrophils. A fever of at least 101℉—or one sustained at 100.4℉ for an hour or more—in a patient with neutropenia signals a severe decrease in neutrophils and may indicate that the immune system is compromised in its ability to ward off infections.
The Infectious Disease Society of America and ASCO have both published guidelines for treating outpatients who have neutropenic fever. Both organizations call for administering an intravenous antibiotic within 60 minutes of fever detection.
Key Findings
In the new study, the researchers examined the data of 187 patients who developed neutropenic fever to determine whether delays in antibiotic treatment affect short-term overall survival. Only 14% of patients received antibiotics within 60 minutes of developing neutropenic fever. The researchers noted that the overall survival rates of these patients after 6 months were not significantly greater than the survival rates of patients who received antibiotics later than recommended.
Further analysis identified several factors that had a statistically significant association with the risk of mortality:
- Patients with insurance had a 72% lower risk of mortality than those without insurance.
- Patients with at least one other major medical condition had a 2.7-fold greater risk of mortality than those with blood cancer alone.
- Patients who were treated with antibiotics within 40 minutes had a 5.7-fold risk of mortality than those who didn’t receive antibiotics so quickly.
A possible explanation for the last finding, the researchers explained, was that patients who received antibiotics within 40 minutes "had other symptoms that yielded a concerning clinical picture, thus leading to a timelier administration of antibiotics, but ultimately a worse clinical outcome."
Guidelines for Outpatient Treatment May Not Apply to Inpatients
Even a delay of more than 4 hours wasn’t long enough to affect overall survival, the researchers determined. That result was consistent with information from previous studies of inpatients with neutropenic fever.
The researchers believe that existing treatment guidelines may be appropriate for patients with neutropenic fever who are treated in a physician’s office or an emergency department—but other factors must be considered for patients who have been admitted to a hospital. “Unlike [patients with] neutropenic fever presenting to the emergency department—where true time to antibiotic administration may often be many hours or even days before arrival—a [delay of a] few hours … in the hospital may not be sufficiently long enough to cause significant patient harm,” they concluded.
The researchers hope to conduct larger studies to analyze the smaller differences in mortality rates for inpatients with neutropenic fever receiving delayed or timely treatment with antibiotics.
Disclosure: For full disclosures of the study authors, visit journals.lww.com.
