My IDSA Contact Us
IDSA NewsPrint-Friendly Newsletter
Forward to a Friend
Search Back Issues
Education & Training Resources Practice Guidelines Journals & Publications Policy & Advocacy Meetings About IDSA
September 2011
Patient Care and Science
EIN Update: CBC Monitoring for ID-Related Diseases

The Emerging Infections Network (EIN) is a forum for infectious diseases consultants and public health officials to report information on clinical phenomena and epidemiological issues with public health significance. Any diagnostic or therapeutic recommendations and all opinions presented are those of the individual contributor. They do not necessarily represent the views of EIN, IDSA (EIN’s sponsor), or the Centers for Disease Control and Prevention (CDC), which funds EIN. The reader assumes all risks in using this information.

EIN members recently discussed the appropriate use of non-microbiologic diagnostic tests, including complete blood counts (CBCs), for infectious diseases.

A member in Florida began the discussion, asking about “the necessity of frequent CBCs on hospitalized patients admitted with infectious diagnoses, for the most part general ID issues (not neutropenic or in the intensive care unit [ICU]). Under what circumstances would you want frequent CBC monitoring (i.e., aside from disseminated intravascular coagulation [DIC] from sepsis and hemolysis from infections such as malaria)?”

A respondent in Minnesota noted that “the same could be asked about inflammatory markers (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], procalcitonin). The trend curves look nice and make us feel good,” the member wrote. “But do they add meaningfully to the bedside clinical assessment?”

An EIN member in Canada reported CBC monitoring “not often and based mostly on clinical assessment first,” sometimes in cases of a fever not yet diagnosed, if the patient’s initial white blood count (WBC) was extremely high, if there is concern about development of hemolytic-uremic syndrome (HUS) in a patient with colitis, or with malaria.

“I've always thought that in general, we order too many CBCs and too many chemistry panels on stable patients,” a member in New Hampshire responded. “I’ll check a CBC more frequently when there are significant abnormalities to begin with (low platelets, for example), or when the patient has a high risk of other complications (septic patient in the ICU, not responding to treatment).”

Short of that, a CBC every two to three days while the patient is in-house is usually reasonable, the member continued, and “maybe not at all when following a patient with something like cellulitis or pneumonia, who is obviously improving and ready for oral antibiotics.”

Daily CBC or electrolyte monitoring do not make sense in regular day-to-day admissions, another member in Canada wrote, “and I don’t mean only for infectious disease related issues. Eventually, the iatrogenic drop in hemoglobin might change our clinical management, but this is avoidable.”

“The only time we ask for regular CBCs is when we treat our patients with long-term high-dose beta-lactam antibiotics (e.g., for osteomyelitis) to monitor drug-induced neutropenia,” the member noted, “and when we start an HIV-exposed newborn on azidothymidine (AZT) to monitor anemia, and this is at most a weekly CBC. I suppose that CBC monitoring with linezolid treatment is also warranted, but we haven’t needed to use this in children.”

For most uncomplicated infectious illnesses, two WBCs are needed, one to assist with initial diagnosis and/or to demonstrate that the patient is having the expected response, and another to document that the WBC is consistent with clinical recovery, an EIN member in Pennsylvania wrote.

“It’s not necessary to get daily WBCs (or chemistry panels or chest x-rays, etc.) in a patient with a solid clinical diagnosis who is clinically improving,” the member continued. “Many of our residents get daily labs regardless of the patient’s clinical progress. This is wasteful, expensive, hard on the patient’s antecubital fossae, and a barrier to learning the essentials of critical thinking.”

A respondent in Tennessee agreed: “‘Following the white count daily’ is almost never helpful in monitoring the clinical course of patients with infectious diseases. In situations where laboratory test results can provide additional evidence of adequate response to therapy, monitoring acute phase reactants, such as C-reactive protein, is much more likely to be of value.”

“Some doctors order daily CBC and differential when CBC without differential is often adequate in many non-ICU patients,” an EIN member in California responded. “We are often asked to do consults for leukocytosis and frequently find the reason.

A consensus on when CBC monitoring is appropriate could lead to savings, the member suggested, although “one would have to balance cost savings with fewer CBCs against missed changes in patient conditions with daily CBC that might interfere with patient care or eventually lead to higher costs.”

E-mail the Emerging Infections Network.

The Emerging Infections Network (EIN) is a provider-based sentinel network designed to help the public health community detect trends in emerging infectious diseases.

A joint project of IDSA and the Pediatric Infectious Diseases Society (PIDS) with funding from the Centers for Disease Control and Prevention (CDC), EIN tracks emerging infectious diseases and keeps the public health community up to date with new disease trends, difficult cases, and other issues affecting members’ clinical practices. The Network provides a great opportunity for members to share knowledge quickly across large geographical distances. Both IDSA and PIDS members are eligible to join. Click here for more information or to join EIN.
How useful is this article?

< Previous Article | Next Article >

Post a comment

Your name:

Your comment:

Patient Care and Science
CDC Makes New Recommendations for Influenza Immunization
EIN Update: CBC Monitoring for ID-Related Diseases
Drug Approvals, Recalls, Adverse Events Update
Global ID
Armed with Research on Early HIV Treatment, HIVMA and Global Center Make Case for More Funding
Congressional Staff Tours U.S.-funded HIV and TB programs in Kenya with Global Center
Science Speaks Interviews Key PEPFAR Staff
Policy and Advocacy
Policy Conference Addresses Lack of New Antibiotics
FDA Rolls Out New Foodborne Illness Response Network
Input Due Oct. 26 on Changes to Rules Protecting Human Research Subjects
IDSA Urges Fix to Flawed Medicare Physician Payment Formula
Your Colleagues
IDSA Congratulates the 2011 Joint Research Award Winners
Congratulations to the 2011 Medical Scholars Program Recipients
In Memoriam: Richard B. Hornick, MD, FIDSA (1929-2011)
Members on the Move
Welcome, New Members!
Education & Resources
New Toolkit Aims to Increase Pneumococcal Immunization in Adults
HIVMA Minority Clinical Fellowship Program: December 9 Application Deadline
Top Stories
From the President: A Year in Review
IDSA, PIDS Release Guidelines for Treating CAP in Children
Quick Guide to the New IDSA Website
IDSA Journal Club
IDSA | 1300 Wilson Blvd., Suite 300 | Arlington, VA 22209 | Phone: (703) 299-0200
To ensure delivery, please add '' to your email address book or Safe Sender List.
If you are still having problems receiving our communications,
see our white-listing page for more details.