March 5th, 2015

Has Lab Testing Become a Blood Sport for Cardiac Surgery Patients?

The CardioExchange Editors interview Colleen G. Koch, lead author of a study of the extent of blood testing in cardiac surgery patients at Cleveland Clinic. The article is published in the Annals of Thoracic Surgery and was covered in a recent CardioExchange news story.


For 1894 patients who underwent cardiac surgery at the Cleveland Clinic from January through June of 2012, there were 221,498 laboratory tests. Of those tests (mean, 115 per patient), 40% measured arterial or venous blood-gas levels, 18% assessed blood coagulation, 14% were for a complete blood count, 13% were for metabolic panels, and 5% were for blood cultures. The cumulative median volume of drawn blood during a hospital stay was 454 mL per patient.


CardioExchange Editors: Any reason to think Cleveland Clinic is better or worse than most hospitals when it comes to testing cardiac surgery patients’ blood?

Koch: Hospital systems vary according to whether they have primarily surgical or medical hospitalizations, the proportion of critically ill patients who require an ICU stay, and patient complexity. Any hospital with a similar ratio of surgical-to-medical hospitalizations and a similar patient acuity (i.e., degree of patient sickness) is likely to have findings similar to ours. If phlebotomy volumes are in excess, the patient is more likely to develop anemia.

Interestingly, in a separate recent investigation, our group studied the percentage of patients who came into the hospital with a normal hemoglobin value (not anemic) and followed their hemoglobin levels throughout hospitalization until hospital discharge to see whether they developed anemia. Among roughly 188,000 patients with medical or surgical hospitalizations in the Cleveland Clinic Health System, more than 70% developed anemia in the hospital. We found that patients who developed hospital-acquired anemia had worse outcomes (Koch et al. J Hosp Med 2013; 8:506). Other investigations report the association between higher phlebotomy volume and development of hospital-acquired anemia, so in the current study we sought to determine the amount of blood drawn for laboratory testing (phlebotomy volume) in the patients we cared for who were undergoing heart surgery.

Editors: You suggest that patients ask questions about the necessity of tests. Is this practical in most cases?

Koch: Yes, patients should be empowered to become more involved in their care and ask questions. Specifically, they should ask whether a test is necessary, should it be done every day, and or can smaller-volume test tubes be used? Cleveland Clinic has become a role model as an organization that embodies “patient-centered care.”

Editors: What can be done to change this culture?

Koch: Change begins with caregivers becoming aware of how their practices and processes influence patient outcomes. Second, you cannot manage what you do not measure. If caregivers were more aware of the total amount of blood taken throughout the care continuum, and how development of anemia relates to patient outcome and resource utilization, they might change how they practice.

Editors: Should this be assessed during hospital certifications?

Koch: Interestingly, 20 years ago, development of infections during the course of hospitalization was an event that occurred not infrequently. With increased measurement and emphasis on the morbidity implications of hospital-acquired infections, this outcome is a current metric for in-hospital quality of care.

I can only imagine that hospital-acquired anemia, which has many contributing factors (excess phlebotomy volume among them), may be on the radar as a possible quality metric, similar to hospital-acquired infections. Hospital-acquired anemia increases hospital resource utilization (total charges, length of stay) and, more important, is associated with greater patient mortality. Our current paper reports an association between increased red-blood-cell transfusion and excess phlebotomy volume. Of note, RBC transfusions are also expensive and have associated morbidity and mortality complications.


Are Dr. Koch’s findings likely to affect how your institution approaches blood testing in cardiac surgery patients? 

5 Responses to “Has Lab Testing Become a Blood Sport for Cardiac Surgery Patients?”

  1. Mark G Perlroth, MD says:

    Has anyone done a study on the frequency and impact of ROUTINE (daily or more often) blood draws (CBC, Metabolic panel, ABG, etc) BOTH within and out of the ICU? These orders are typically renewed and maintained throughout the hospital stay regardless of the acuity of the patient on standard medical/surgical wards. The amount of blood drawn and the markedly inflated cost both must account for a great deal of biologic and financial waste.

  2. Louis Krut, MB.ChB. MD says:

    It seems to me I am a member of a profession peopled by nuts.
    Time is past due to take stock of what we do.

    Thank you Dr. Koch for bringing this alarming information to the fore. I do hope your findings persist in the conscious concern of everyone.

  3. Maarten Vasbinder, MD says:

    This happened in the Netherlands in the eighties, until someone began wondering, why so many patients became anemic during hospital stay. The anemia lead to more blood tests, many specialists got involved etc. etc.
    It became a vicious circle. As Louis Krut says, anemia caused by nuts.
    This time it does not seem a question of nuts, but more like acting out of greed, which could be criminal.
    So, please let the doctors involved explain why. Surely, they do not know an answer other than:”policy of the hospital”.

  4. Karen Politis, MD says:

    I should like to point out that in my experience of surgical patients, one might get the wrong picture if only measuring the haemoglobin at admission and discharge. Many surgical patients on admission are dehydrated, or victims of very recent trauma, and their initial haemoglobin counts are falsely elevated. After a period of surgery, metabolic stress, anorexia and inability to digest properly, many patients are discharged stable, but slightly anaemic, until they eventually recover.
    Of course repeated and futile bloodletting and testing in stable patients make no sense at all. It is painful and very expensive, takes up staff time and wastes reagents.

  5. Jean-Pierre Usdin, MD says:

    Thank you for this wonderful and helpful study.
    Unfortunately the hospital where I work is totally unable to listen to this kind of requirement!
    About four years ago a study very close to yours was also published (I will eventually find the references. if I remember well it was patients suffering from myocardial infarct…) and I discussed with the Director of Quality (administrative) and Laboratory Chief (medical biologist) of the necessity to use for CCU patients (or other very sick ones)micro tubes as we do with children: no answer came.
    More recently I started again toward a new lab director supposing also some progresses are came in the field of blood draws: capillary samples and micro tubes did not work.
    I have however to confess that we have no medical paediatrics department in our institution
    But this is a very big problem to solve. Patients hospitalized in oncology are dramatically concerned.