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374
THOUGHTS AND PROGRESS
Restrictive Transfusion Practice During Extracorporeal Membrane Oxygenation Therapy for Severe Acute Respiratory Distress Syndrome Maria T. Voelker, Thilo Busch, Sven Bercker, Falk Fichtner, Udo X. Kaisers, and Sven Laudi Department of Anesthesiology and Intensive Care Medicine, University of Leipzig, Leipzig, Germany Abstract: Recommendations concerning the management of hemoglobin levels and hematocrit in patients on extracorporeal membrane oxygenation (ECMO) still advise maintenance of a normal hematocrit. In contrast, current transfusion guidelines for critically ill patients support restrictive transfusion practice. We report on a series of patients receiving venovenous ECMO (vvECMO) for acute respiratory distress syndrome (ARDS) treated according to the restrictive transfusion regimen recommended for critically ill patients. We retrospectively analyzed 18 patients receiving vvECMO due to severe ARDS. Hemoglobin concentrations were kept between 7 and 9 g/dL with a transfusion trigger at 7 g/dL or when physiological transfusion triggers were apparent. We assessed baseline data, hospital mortality, time on ECMO, hemoglobin levels, hematocrit, quantities of packed red blood cells received, and lactate concentrations and compared survivors and nonsurvivors. The overall mortality of all patients on vvECMO was 38.9%. Mean hemoglobin concentration over all patients and ECMO days was 8.30 ± 0.51 g/dL, and hematocrit was 0.25 ± 0.01, with no difference between survivors and nonsurvivors. Mean numbers of given PRBCs showed a trend towards higher quantities in the group of nonsurvivors, but the difference was not significant (1.97 ± 1.47 vs. 0.96 ± 0.76 units; P = 0.07). Mean lactate clearance from the first to the third day was 45.4 ± 28.3%, with no significant difference between survivors and nonsurvivors (P = 0.19). In our cohort of patients treated with ECMO due to severe ARDS, the application of a restrictive transfusion protocol did not result in an increased mortality. Safety and feasibility of the application of a restrictive transfusion protocol
doi:10.1111/aor.12385 Received January 2014; revised July 2014. Address correspondence and reprint requests to Ms. Maria T. Voelker, Department of Anesthesiology and Intensive Care Medicine, University of Leipzig, Medical Faculty, Liebigstrasse 20, Leipzig, Saxony D-04103, Germany. E-mail: theresa.voelker@ medizin.uni-leipzig.de Presented in part at the American Thoracic Society International Conference, held May 18–23, 2012 in San Francisco, CA, USA. Artif Organs, Vol. 39, No. 4, 2015
THOUGHTS AND PROGRESS in patients on ECMO must further be evaluated in randomized controlled trials. Key Words: Extracorporeal membrane oxygenation—Hemoglobin—Hematocrit— Transfusion—Acute respiratory distress syndrome.
What need the bridge much broader than the flood? William Shakespeare, Much Ado About Nothing The management of hemoglobin levels and the use of packed red blood cells (PRBCs) in patients receiving extracorporeal membrane oxygenation (ECMO) as rescue therapy for refractory hypoxia in acute respiratory distress syndrome (ARDS) are the subject of controversy. Recommendations published by the Extracorporeal Life Support Organization (ELSO) advise maintaining a normal hematocrit during ECMO treatment (1). However, these guidelines are not intended as a standard of care, as they are not based on consensus recommendations. Modern ECMO devices are now reported to show significantly fewer hemolysis and bleeding complications than the technology used when these transfusion recommendations for patients on ECMO were made. Additionally, as many randomized controlled studies have shown that critically ill patients profit from a more restrictive transfusion regimen, current guidelines on transfusions of red blood cells recommend restrictive strategies that take possible symptoms of anemic hypoxia into account in the decision process (2–4). Considering this change in general transfusion practice and taking into account the general improvements in experience and equipment for ECMO therapy, the use of red blood cell transfusions and the management of hemoglobin levels in patients on ECMO should be revaluated. We report a series of ARDS patients receiving venovenous ECMO (vvECMO) for hypoxemia due to severe ARDS treated according to the same restrictive transfusion schema as recommended for critically ill patients. PATIENTS AND METHODS We retrospectively analyzed a series of 18 ARDS patients receiving vvECMO as rescue therapy for refractory hypoxemia due to severe ARDS at the ECMO center of the University Hospital of Leipzig, Germany. We included all patients treated with vvECMO for ARDS in our intensive care unit between 2009 and 2011. The indication for ECMO therapy was refractory hypoxemia. ECMO was run using centrifugal pumps (Rotaflow or Cardiohelp, Maquet, Rastatt, Germany) and hollow-fiber membrane oxygenators made of polymethylpentene (Quadrox, Maquet). Pump rotation and resulting ECMO flow, as well as fraction of oxygen in sweep
375
gas, were adjusted to ensure arterial oxygen saturation above 92%. Hemoglobin concentrations were kept between 7 and 9 g/dL with a transfusion trigger at 7 g/dL or when physiological transfusion triggers were apparent. PRBCs were provided by the hospital’s internal transfusion laboratory. We recorded patients’ baseline characteristics and their blood hemoglobin concentrations, hematocrit, number of PRBCs received, and arterial lactate levels while they were on ECMO. Arterial lactate levels above 2.2 mmol/L were considered to indicate impaired oxygen delivery. Counts of all units of PRBCs received per day were made. Platelets, fresh-frozen plasma, and fibrinogen infusions were administered if clinical bleeding events occurred or patients were at an exceptionally high risk for bleeding events. Inhospital mortality was assessed, and two groups, survivors and nonsurvivors, were delineated. All results are expressed as mean ± standard deviation (SD). Differences between groups were compared with Student’s t-test for continuous variables and Fisher’s exact test for categorical variables. Differences with P values
374
THOUGHTS AND PROGRESS
Restrictive Transfusion Practice During Extracorporeal Membrane Oxygenation Therapy for Severe Acute Respiratory Distress Syndrome Maria T. Voelker, Thilo Busch, Sven Bercker, Falk Fichtner, Udo X. Kaisers, and Sven Laudi Department of Anesthesiology and Intensive Care Medicine, University of Leipzig, Leipzig, Germany Abstract: Recommendations concerning the management of hemoglobin levels and hematocrit in patients on extracorporeal membrane oxygenation (ECMO) still advise maintenance of a normal hematocrit. In contrast, current transfusion guidelines for critically ill patients support restrictive transfusion practice. We report on a series of patients receiving venovenous ECMO (vvECMO) for acute respiratory distress syndrome (ARDS) treated according to the restrictive transfusion regimen recommended for critically ill patients. We retrospectively analyzed 18 patients receiving vvECMO due to severe ARDS. Hemoglobin concentrations were kept between 7 and 9 g/dL with a transfusion trigger at 7 g/dL or when physiological transfusion triggers were apparent. We assessed baseline data, hospital mortality, time on ECMO, hemoglobin levels, hematocrit, quantities of packed red blood cells received, and lactate concentrations and compared survivors and nonsurvivors. The overall mortality of all patients on vvECMO was 38.9%. Mean hemoglobin concentration over all patients and ECMO days was 8.30 ± 0.51 g/dL, and hematocrit was 0.25 ± 0.01, with no difference between survivors and nonsurvivors. Mean numbers of given PRBCs showed a trend towards higher quantities in the group of nonsurvivors, but the difference was not significant (1.97 ± 1.47 vs. 0.96 ± 0.76 units; P = 0.07). Mean lactate clearance from the first to the third day was 45.4 ± 28.3%, with no significant difference between survivors and nonsurvivors (P = 0.19). In our cohort of patients treated with ECMO due to severe ARDS, the application of a restrictive transfusion protocol did not result in an increased mortality. Safety and feasibility of the application of a restrictive transfusion protocol
doi:10.1111/aor.12385 Received January 2014; revised July 2014. Address correspondence and reprint requests to Ms. Maria T. Voelker, Department of Anesthesiology and Intensive Care Medicine, University of Leipzig, Medical Faculty, Liebigstrasse 20, Leipzig, Saxony D-04103, Germany. E-mail: theresa.voelker@ medizin.uni-leipzig.de Presented in part at the American Thoracic Society International Conference, held May 18–23, 2012 in San Francisco, CA, USA. Artif Organs, Vol. 39, No. 4, 2015
THOUGHTS AND PROGRESS in patients on ECMO must further be evaluated in randomized controlled trials. Key Words: Extracorporeal membrane oxygenation—Hemoglobin—Hematocrit— Transfusion—Acute respiratory distress syndrome.
What need the bridge much broader than the flood? William Shakespeare, Much Ado About Nothing The management of hemoglobin levels and the use of packed red blood cells (PRBCs) in patients receiving extracorporeal membrane oxygenation (ECMO) as rescue therapy for refractory hypoxia in acute respiratory distress syndrome (ARDS) are the subject of controversy. Recommendations published by the Extracorporeal Life Support Organization (ELSO) advise maintaining a normal hematocrit during ECMO treatment (1). However, these guidelines are not intended as a standard of care, as they are not based on consensus recommendations. Modern ECMO devices are now reported to show significantly fewer hemolysis and bleeding complications than the technology used when these transfusion recommendations for patients on ECMO were made. Additionally, as many randomized controlled studies have shown that critically ill patients profit from a more restrictive transfusion regimen, current guidelines on transfusions of red blood cells recommend restrictive strategies that take possible symptoms of anemic hypoxia into account in the decision process (2–4). Considering this change in general transfusion practice and taking into account the general improvements in experience and equipment for ECMO therapy, the use of red blood cell transfusions and the management of hemoglobin levels in patients on ECMO should be revaluated. We report a series of ARDS patients receiving venovenous ECMO (vvECMO) for hypoxemia due to severe ARDS treated according to the same restrictive transfusion schema as recommended for critically ill patients. PATIENTS AND METHODS We retrospectively analyzed a series of 18 ARDS patients receiving vvECMO as rescue therapy for refractory hypoxemia due to severe ARDS at the ECMO center of the University Hospital of Leipzig, Germany. We included all patients treated with vvECMO for ARDS in our intensive care unit between 2009 and 2011. The indication for ECMO therapy was refractory hypoxemia. ECMO was run using centrifugal pumps (Rotaflow or Cardiohelp, Maquet, Rastatt, Germany) and hollow-fiber membrane oxygenators made of polymethylpentene (Quadrox, Maquet). Pump rotation and resulting ECMO flow, as well as fraction of oxygen in sweep
375
gas, were adjusted to ensure arterial oxygen saturation above 92%. Hemoglobin concentrations were kept between 7 and 9 g/dL with a transfusion trigger at 7 g/dL or when physiological transfusion triggers were apparent. PRBCs were provided by the hospital’s internal transfusion laboratory. We recorded patients’ baseline characteristics and their blood hemoglobin concentrations, hematocrit, number of PRBCs received, and arterial lactate levels while they were on ECMO. Arterial lactate levels above 2.2 mmol/L were considered to indicate impaired oxygen delivery. Counts of all units of PRBCs received per day were made. Platelets, fresh-frozen plasma, and fibrinogen infusions were administered if clinical bleeding events occurred or patients were at an exceptionally high risk for bleeding events. Inhospital mortality was assessed, and two groups, survivors and nonsurvivors, were delineated. All results are expressed as mean ± standard deviation (SD). Differences between groups were compared with Student’s t-test for continuous variables and Fisher’s exact test for categorical variables. Differences with P values
