ADULT CARDIAC
784
KOCH ET AL PERIOPERATIVE BLOODLETTING
devices, such as closed loop devices, have been demonstrated to reduce red blood cell transfusion requirements because they eliminate the need for discarded volume [14]. We have trialed such products; however, they were removed from clinical care because of technical issues. We are currently modifying our existing arterial line setup to reduce discard volumes from 7 to 10 mL to approximately 3 mL. Effective process improvement involves real-time feedback to assist with clinical decision-making. Providing a cumulative tally of overall phlebotomy volume per patient similar to blood pressure and weight should enable caregiver discussions on the necessity of specific laboratory testing on a daily basis. Although we recognize that arterial blood gas values are often used to assess factors other than making adjustments to the ventilator and weaning protocols, there may be a role for capnography and pulse oximetry in decision-making surrounding ventilator adjustments.
Limitations Our study is observational and hence has many of the limitations associated with such a study design. Our work is intended to be descriptive to enable us to improve patient care in the cardiovascular surgery setting. Our ability to determine the phlebotomy volumes with high accuracy is limited, so the volume data presented here should be regarded as estimated. Because our population was exclusively from our Heart and Vascular Institute, cumulative phlebotomy volume may not be broadly applicable to other surgical service lines or other institutions. We report an association rather than causation between increasing phlebotomy volumes and increasing transfusion requirements, recognizing that both are simultaneously evolving events during a patient’s hospital course, and we are aware that a number of factors are involved in transfusion decisions. However, regardless of patient comorbidity, preexisting anemia, length of stay, and case complexity, removing phlebotomy volumes equivalent to multiple red blood cell units likely contributed to reductions in hemoglobin values during the course of hospitalization, which is the primary trigger for transfusion in our setting. We did not have information on hemoglobin values at the time of transfusion or estimates for perioperative blood loss. Furthermore, we were unable to determine appropriateness of the laboratory testing performed; however, many tests are ordered as part of the clinical routine, rather than in response to a patient’s condition.
Ann Thorac Surg 2015;99:779–85
Conclusions Our intent was to examine the amount of phlebotomy volume from diagnostic laboratory testing to gain insight into future process improvement initiatives for our cardiac surgical patients. We were amazed by the extent of bloodletting, with total phlebotomy volumes approaching amounts equivalent to 1 to 2 red blood cell units. Excessive bloodletting has consequences in terms of contributing to reductions in hemoglobin levels and subsequent need for red blood transfusions. Implementation of process improvement initiatives with careful monitoring should result in reduced phlebotomy volumes, better use of limited resources, and improved patient outcome.
References 1. Eyster E, Bernene J. Nosocomial anemia. JAMA 1973; 223:73–4. 2. Koch CG, Li L, Sun Z, et al. Hospital-acquired anemia: prevalence, outcomes, and healthcare implications. J Hosp Med 2013;8:506–12. 3. Salisbury AC, Reid KJ, Alexander KP, et al. Diagnostic blood loss from phlebotomy and hospital-acquired anemia during acute myocardial infarction. Arch Intern Med 2011;171: 1646–53. 4. Salisbury AC, Amin AP, Reid KJ, et al. Hospital-acquired anemia and in-hospital mortality in patients with acute myocardial infarction. Am Heart J 2011;162:300–9.e3. 5. Chant C, Wilson G, Friedrich JO. Anemia, transfusion, and phlebotomy practices in critically ill patients with prolonged ICU length of stay: a cohort study. Crit Care 2006;10: R140. 6. Napolitano LM. Scope of the problem: epidemiology of anemia and use of blood transfusions in critical care. Crit Care 2004;8(Suppl 2):S1–8. 7. Shander A. Anemia in the critically ill. Crit Care Clin 2004;20: 159–78. 8. Krafte-Jacobs B. Anemia of critical illness and erythropoietin deficiency. Intensive Care Med 1997;23:137–8. 9. Nguyen BV, Bota DP, M elot C, Vincent JL. Time course of hemoglobin concentrations in nonbleeding intensive care unit patients. Crit Care Med 2003;31:406–10. 10. Corwin HL, Parsonnet KC, Gettinger A. RBC transfusion in the ICU. Is there a reason? Chest 1995;108:767–71. 11. Smoller BR, Kruskall MS. Phlebotomy for diagnostic laboratory tests in adults. Pattern of use and effect on transfusion requirements. N Engl J Med 1986;314:1233–5. 12. Shaffer C. Diagnostic blood loss in mechanically ventilated patients. Heart Lung 2007;36:217–22. 13. Sanchez-Giron F, Alvarez-Mora F. Reduction of blood loss from laboratory testing in hospitalized adult patients using small-volume (pediatric) tubes. Arch Pathol Lab Med 2008;132:1916–9. 14. Mukhopadhyay A, Yip HS, Prabhuswamy D, et al. The use of a blood conservation device to reduce red blood cell transfusion requirements: a before and after study. Crit Care 2010;14:R7.
INVITED COMMENTARY Wow! Postoperative cardiac surgical procedure patients lose, on average, a unit of blood for blood tests. Some lose a lot more. Patients averaged 115 blood draws. Although we may suspect that our patients lose a lot of blood from tests, these authors [1] quantitate it, and it’s a lot. Some
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
patients probably lost more blood from tests than they lost from the operation itself! We make efforts to minimize intraoperative blood loss—antifibrinolytics, topical hemostatic agents, cell scavenging systems, and so forth. We need to make similar efforts postoperatively.
0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.10.054
Whereas some may argue that transfusion itself is not harmful, but only a marker of a sicker patient, few would argue that avoiding anemia and transfusion is not the best course for the patient. So how best to limit postoperative bloodletting? The authors make several good suggestions to decrease bloodletting: use of smaller tubes, better blood conservation devices so less blood is wasted, and noninvasive monitors. But we also need to step back and ask, “Does this patient need this test?” Are we getting the test because the answer will change therapy? Or are we getting the test from habit or other inappropriate reason? Avoiding unnecessary blood tests will not only help prevent anemia (and maybe transfusion) but will also save money.
KOCH ET AL PERIOPERATIVE BLOODLETTING
785
Milo Engoren, MD Department of Anesthesiology University of Michigan 4172 Cardiovascular Center Ann Arbor, MI 48109-5861 e-mail: [email protected]
Reference 1. Koch CG, Reineks EZ, Tang AS, et al. Contemporary bloodletting in cardiac surgical care. Ann Thorac Surg 2015;99: 779–85.
ADULT CARDIAC
Ann Thorac Surg 2015;99:779–85
784
KOCH ET AL PERIOPERATIVE BLOODLETTING
devices, such as closed loop devices, have been demonstrated to reduce red blood cell transfusion requirements because they eliminate the need for discarded volume [14]. We have trialed such products; however, they were removed from clinical care because of technical issues. We are currently modifying our existing arterial line setup to reduce discard volumes from 7 to 10 mL to approximately 3 mL. Effective process improvement involves real-time feedback to assist with clinical decision-making. Providing a cumulative tally of overall phlebotomy volume per patient similar to blood pressure and weight should enable caregiver discussions on the necessity of specific laboratory testing on a daily basis. Although we recognize that arterial blood gas values are often used to assess factors other than making adjustments to the ventilator and weaning protocols, there may be a role for capnography and pulse oximetry in decision-making surrounding ventilator adjustments.
Limitations Our study is observational and hence has many of the limitations associated with such a study design. Our work is intended to be descriptive to enable us to improve patient care in the cardiovascular surgery setting. Our ability to determine the phlebotomy volumes with high accuracy is limited, so the volume data presented here should be regarded as estimated. Because our population was exclusively from our Heart and Vascular Institute, cumulative phlebotomy volume may not be broadly applicable to other surgical service lines or other institutions. We report an association rather than causation between increasing phlebotomy volumes and increasing transfusion requirements, recognizing that both are simultaneously evolving events during a patient’s hospital course, and we are aware that a number of factors are involved in transfusion decisions. However, regardless of patient comorbidity, preexisting anemia, length of stay, and case complexity, removing phlebotomy volumes equivalent to multiple red blood cell units likely contributed to reductions in hemoglobin values during the course of hospitalization, which is the primary trigger for transfusion in our setting. We did not have information on hemoglobin values at the time of transfusion or estimates for perioperative blood loss. Furthermore, we were unable to determine appropriateness of the laboratory testing performed; however, many tests are ordered as part of the clinical routine, rather than in response to a patient’s condition.
Ann Thorac Surg 2015;99:779–85
Conclusions Our intent was to examine the amount of phlebotomy volume from diagnostic laboratory testing to gain insight into future process improvement initiatives for our cardiac surgical patients. We were amazed by the extent of bloodletting, with total phlebotomy volumes approaching amounts equivalent to 1 to 2 red blood cell units. Excessive bloodletting has consequences in terms of contributing to reductions in hemoglobin levels and subsequent need for red blood transfusions. Implementation of process improvement initiatives with careful monitoring should result in reduced phlebotomy volumes, better use of limited resources, and improved patient outcome.
References 1. Eyster E, Bernene J. Nosocomial anemia. JAMA 1973; 223:73–4. 2. Koch CG, Li L, Sun Z, et al. Hospital-acquired anemia: prevalence, outcomes, and healthcare implications. J Hosp Med 2013;8:506–12. 3. Salisbury AC, Reid KJ, Alexander KP, et al. Diagnostic blood loss from phlebotomy and hospital-acquired anemia during acute myocardial infarction. Arch Intern Med 2011;171: 1646–53. 4. Salisbury AC, Amin AP, Reid KJ, et al. Hospital-acquired anemia and in-hospital mortality in patients with acute myocardial infarction. Am Heart J 2011;162:300–9.e3. 5. Chant C, Wilson G, Friedrich JO. Anemia, transfusion, and phlebotomy practices in critically ill patients with prolonged ICU length of stay: a cohort study. Crit Care 2006;10: R140. 6. Napolitano LM. Scope of the problem: epidemiology of anemia and use of blood transfusions in critical care. Crit Care 2004;8(Suppl 2):S1–8. 7. Shander A. Anemia in the critically ill. Crit Care Clin 2004;20: 159–78. 8. Krafte-Jacobs B. Anemia of critical illness and erythropoietin deficiency. Intensive Care Med 1997;23:137–8. 9. Nguyen BV, Bota DP, M elot C, Vincent JL. Time course of hemoglobin concentrations in nonbleeding intensive care unit patients. Crit Care Med 2003;31:406–10. 10. Corwin HL, Parsonnet KC, Gettinger A. RBC transfusion in the ICU. Is there a reason? Chest 1995;108:767–71. 11. Smoller BR, Kruskall MS. Phlebotomy for diagnostic laboratory tests in adults. Pattern of use and effect on transfusion requirements. N Engl J Med 1986;314:1233–5. 12. Shaffer C. Diagnostic blood loss in mechanically ventilated patients. Heart Lung 2007;36:217–22. 13. Sanchez-Giron F, Alvarez-Mora F. Reduction of blood loss from laboratory testing in hospitalized adult patients using small-volume (pediatric) tubes. Arch Pathol Lab Med 2008;132:1916–9. 14. Mukhopadhyay A, Yip HS, Prabhuswamy D, et al. The use of a blood conservation device to reduce red blood cell transfusion requirements: a before and after study. Crit Care 2010;14:R7.
INVITED COMMENTARY Wow! Postoperative cardiac surgical procedure patients lose, on average, a unit of blood for blood tests. Some lose a lot more. Patients averaged 115 blood draws. Although we may suspect that our patients lose a lot of blood from tests, these authors [1] quantitate it, and it’s a lot. Some
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
patients probably lost more blood from tests than they lost from the operation itself! We make efforts to minimize intraoperative blood loss—antifibrinolytics, topical hemostatic agents, cell scavenging systems, and so forth. We need to make similar efforts postoperatively.
0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.10.054
Whereas some may argue that transfusion itself is not harmful, but only a marker of a sicker patient, few would argue that avoiding anemia and transfusion is not the best course for the patient. So how best to limit postoperative bloodletting? The authors make several good suggestions to decrease bloodletting: use of smaller tubes, better blood conservation devices so less blood is wasted, and noninvasive monitors. But we also need to step back and ask, “Does this patient need this test?” Are we getting the test because the answer will change therapy? Or are we getting the test from habit or other inappropriate reason? Avoiding unnecessary blood tests will not only help prevent anemia (and maybe transfusion) but will also save money.
KOCH ET AL PERIOPERATIVE BLOODLETTING
785
Milo Engoren, MD Department of Anesthesiology University of Michigan 4172 Cardiovascular Center Ann Arbor, MI 48109-5861 e-mail: [email protected]
Reference 1. Koch CG, Reineks EZ, Tang AS, et al. Contemporary bloodletting in cardiac surgical care. Ann Thorac Surg 2015;99: 779–85.
ADULT CARDIAC
Ann Thorac Surg 2015;99:779–85
