Vox Sanguinis (2015) 109, 280–286 © 2015 International Society of Blood Transfusion DOI: 10.1111/vox.12280
ORIGINAL PAPER
Intra-operative cell salvage in cardiac surgery may increase platelet transfusion requirements: a cohort study A. Z. Al-Riyami,1 M. Al-Khabori,1 B. Baskaran,2 M. Siddiqi2 & H. Al-Sabti2 1
Department of Hematology, Sultan Qaboos University Hospital, Muscat, Oman Department of Surgery, Cardiothoracic Surgery Division, Sultan Qaboos University Hospital, Muscat, Oman
2
Background and Objectives The cell saver (CS) has been widely utilized in cardiac surgery to reduce red blood cell (RBC) transfusion. We aim at examining its effect on the rate of allogeneic transfusion, morbidity and mortality in our population. Materials and Methods Retrospective review of all patients operated at the Sultan Qaboos University Hospital between 2008 and 2013 was performed. Patients’ demographics, comorbidities and surgical details were retrieved. Study end-points included blood transfusion, infection, renal failure and mortality. Baseline characteristics of both groups were compared and differences were adjusted for in the multivariable logistic regression. Results A total of 673 patients were included (CS = 395, non-CS = 278). Baseline characteristics were similar except for systemic hypertension, congestive heart failure and use of cardiopulmonary bypass. The CS group had higher transfusion rates of platelets (CS 36% vs. non-CS 18%; P < 0001) and plasma (CS 31% vs. non-CS 19%; P < 0001). After adjusting for baseline differences, CS use increased the odds of receiving platelet transfusion (odds ratio (OR) 32; P < 0001) but not of plasma transfusion (OR 16; P = 0087). There was no difference in the rate of RBC transfusion (CS 45% vs. non-CS 40%; P = 0212), renal failure (CS 11% vs. non-CS 6%; P = 0139), infection (CS 16% vs. non-CS 13%; P = 0434) and mortality (CS 5% vs. non-CS 2%; P = 0146). Received: 19 September 2014, revised 23 February 2015, accepted 27 February 2015, published online 20 April 2015
Conclusion The CS use increases platelet requirements and has no impact on the rate of RBC transfusion in our population. These findings warrant caution with generalized use and require larger studies to confirm its results. Key words: platelet transfusion, transfusion strategy, transfusion-surgery.
Introduction Cardiac surgery is a major procedure that is anticipated to require significant transfusion support that varies based on many predictors [1, 2]. Despite the presence of current guidelines of transfusion in cardiac surgery [3, 4], there is a wide variation in the transfusion rates ranging from 40% to 90% [5–7].
Correspondence: Dr. Hilal Al-Sabti, MD, MSc, FRCSc, Department of Surgery, Cardiothoracic Surgery Division, Sultan Qaboos University Hospital, P.O box 38, Post Code 123 Muscat, Oman E-mail: [email protected]
280
Different modalities were developed to reduce the rate of allogenic red blood cell (RBC) transfusion [8]. The use of the cell saver (CS) has gained interest as a blood conservation modality [9–11]. Some studies have reported its benefits in reducing the need of RBC transfusion in patients undergoing cardiac surgery [12–14], while others showed benefit in increasing postoperative haemoglobin level [15]. The introduction of the filtration and wash steps of recovered blood during cell salvage has an advantage of reducing proinflammatory and procoagulant substances [16–18]. Based on the available evidence, the use of the CS is recommended for all patients undergoing cardiac surgery with exception of those with active infection [3]. However, secondary dilutional coagulopathy due
Cell salvage in cardiac surgery 281
to the removal of platelets, plasma proteins and coagulation factors were raised by some authors as a concern behind increased rates of postoperative bleeding and plasma and platelet transfusion observed [19–21]. The benefit of the routine use of the CS in all cardiac procedures has been questioned by some authors [13, 22], while others suggested selective use in high-risks patients [18, 23, 24]. Despite the widely available data on the CS use in the literature, there are no studies to assess its benefit in populations with high prevalence of haemolytic anaemia, which by itself imposes an additional demand on transfusion support. The aim of this study was to assess the impact of the CS use in the need for allogeneic platelet and plasma transfusion. Moreover, we aim at assessing the impact of its use on RBC transfusion in our population, which has a high rate of inherited haemolytic anaemias. Morbidity and mortality are assessed as secondary end-points.
Materials and methods This study has been approved by the local ethics committee. Retrospective review of clinical, surgical and laboratory details of all patients who underwent cardiac surgery at the Sultan Qaboos University Hospital between 2008 and 2013 was performed. The CS has been implemented in the unit in 2010 and has been in routine use for all patients undergoing cardiac surgery since then. Therefore, the examined data included two consecutive patient cohorts: those who were operated without the CS (non-CS group) and those with it (CS group). Both elective and emergent cardiac surgeries were included. This included on-pump and off-pump coronary artery bypass grafting (CABG), valve surgery, combination of both, as well as other surgical procedures (e.g. aortic artery dissection surgeries). A standardized anaesthesia protocol was used for all patients. Patients were heparinized at 300 IU/kg heparin to achieve an activated clotting time above 480 s. Cardiopulmonary bypass (CPB) was performed in most of the patients. CPB was performed using the same heart–lung machine (Stockert Sorin SIII; Sorin Biomedica, Milan, Italy) with a centrifugal pump, a 40-lm arterial filter and a priming volume of 30 ml/kg body weight of a crystalloid solution (Plasmalyte, Baxter Healthcare, Deerfield, Illinois, USA). Membrane oxygenator was used in all cases. Both antigrade and retrograde blood cardioplegia were utilized. At the end of the procedure, heparin is reversed with protamine sulphate at a dose of 1 mg/100 IU of heparin. The same CS device (Autolog, Medtronic, Minnesota, USA) was used for all patients who had it used. The CS is routinely used throughout the operation. Processed volume includes all surgically shed blood retrieved from the © 2015 International Society of Blood Transfusion Vox Sanguinis (2015) 109, 280–286
cardiac field as well as residual extracorporeal circuit volume. The CS device was used during full heparinization of the patient and according to the manufacturer recommendations. The collected volume is recovered into the CS reservoir and is processed in a 250-ml centrifuge bowl. Minimum of 600 ml of collection is required for processing the blood by the CS. After plasma removal, the RBC unit is washed with 09% normal saline and is checked for volume, haemoglobin (Hb), haematocrit (Hct) and potassium levels. The concentrated RBCs are collected into a labelled collection bag, and the unit is transfused to the patient using a blood transfusion filter (PALL SQ40SE, Pall Medical, Oss, the Netherlands). Patients undergoing cardiac surgery with CPB have retrieved blood from cardiotomy suction in addition to what is collected for cell salvage. Retrieved volumes via the cardiotomy suction get infused back to the patient intraoperatively without it been processed. All patients were intra-operatively and postoperatively transfused as per a local transfusion protocol. The transfusion protocol was developed by consensus and was implemented in 2008 upon the start of the unit. Intraoperative allogeneic RBC transfusion is performed aiming a Hct level of >23%. All CS group patients are transfused with the salvaged RBCs in the immediate postoperative period. Allogeneic RBCs are transfused perioperatively when the haemoglobin levels fall below 80 g/l, or if there are clinical signs of bleeding. Random donor buffy coat platelets are transfused if signs of bleeding exist with platelet (PLT) count
ORIGINAL PAPER
Intra-operative cell salvage in cardiac surgery may increase platelet transfusion requirements: a cohort study A. Z. Al-Riyami,1 M. Al-Khabori,1 B. Baskaran,2 M. Siddiqi2 & H. Al-Sabti2 1
Department of Hematology, Sultan Qaboos University Hospital, Muscat, Oman Department of Surgery, Cardiothoracic Surgery Division, Sultan Qaboos University Hospital, Muscat, Oman
2
Background and Objectives The cell saver (CS) has been widely utilized in cardiac surgery to reduce red blood cell (RBC) transfusion. We aim at examining its effect on the rate of allogeneic transfusion, morbidity and mortality in our population. Materials and Methods Retrospective review of all patients operated at the Sultan Qaboos University Hospital between 2008 and 2013 was performed. Patients’ demographics, comorbidities and surgical details were retrieved. Study end-points included blood transfusion, infection, renal failure and mortality. Baseline characteristics of both groups were compared and differences were adjusted for in the multivariable logistic regression. Results A total of 673 patients were included (CS = 395, non-CS = 278). Baseline characteristics were similar except for systemic hypertension, congestive heart failure and use of cardiopulmonary bypass. The CS group had higher transfusion rates of platelets (CS 36% vs. non-CS 18%; P < 0001) and plasma (CS 31% vs. non-CS 19%; P < 0001). After adjusting for baseline differences, CS use increased the odds of receiving platelet transfusion (odds ratio (OR) 32; P < 0001) but not of plasma transfusion (OR 16; P = 0087). There was no difference in the rate of RBC transfusion (CS 45% vs. non-CS 40%; P = 0212), renal failure (CS 11% vs. non-CS 6%; P = 0139), infection (CS 16% vs. non-CS 13%; P = 0434) and mortality (CS 5% vs. non-CS 2%; P = 0146). Received: 19 September 2014, revised 23 February 2015, accepted 27 February 2015, published online 20 April 2015
Conclusion The CS use increases platelet requirements and has no impact on the rate of RBC transfusion in our population. These findings warrant caution with generalized use and require larger studies to confirm its results. Key words: platelet transfusion, transfusion strategy, transfusion-surgery.
Introduction Cardiac surgery is a major procedure that is anticipated to require significant transfusion support that varies based on many predictors [1, 2]. Despite the presence of current guidelines of transfusion in cardiac surgery [3, 4], there is a wide variation in the transfusion rates ranging from 40% to 90% [5–7].
Correspondence: Dr. Hilal Al-Sabti, MD, MSc, FRCSc, Department of Surgery, Cardiothoracic Surgery Division, Sultan Qaboos University Hospital, P.O box 38, Post Code 123 Muscat, Oman E-mail: [email protected]
280
Different modalities were developed to reduce the rate of allogenic red blood cell (RBC) transfusion [8]. The use of the cell saver (CS) has gained interest as a blood conservation modality [9–11]. Some studies have reported its benefits in reducing the need of RBC transfusion in patients undergoing cardiac surgery [12–14], while others showed benefit in increasing postoperative haemoglobin level [15]. The introduction of the filtration and wash steps of recovered blood during cell salvage has an advantage of reducing proinflammatory and procoagulant substances [16–18]. Based on the available evidence, the use of the CS is recommended for all patients undergoing cardiac surgery with exception of those with active infection [3]. However, secondary dilutional coagulopathy due
Cell salvage in cardiac surgery 281
to the removal of platelets, plasma proteins and coagulation factors were raised by some authors as a concern behind increased rates of postoperative bleeding and plasma and platelet transfusion observed [19–21]. The benefit of the routine use of the CS in all cardiac procedures has been questioned by some authors [13, 22], while others suggested selective use in high-risks patients [18, 23, 24]. Despite the widely available data on the CS use in the literature, there are no studies to assess its benefit in populations with high prevalence of haemolytic anaemia, which by itself imposes an additional demand on transfusion support. The aim of this study was to assess the impact of the CS use in the need for allogeneic platelet and plasma transfusion. Moreover, we aim at assessing the impact of its use on RBC transfusion in our population, which has a high rate of inherited haemolytic anaemias. Morbidity and mortality are assessed as secondary end-points.
Materials and methods This study has been approved by the local ethics committee. Retrospective review of clinical, surgical and laboratory details of all patients who underwent cardiac surgery at the Sultan Qaboos University Hospital between 2008 and 2013 was performed. The CS has been implemented in the unit in 2010 and has been in routine use for all patients undergoing cardiac surgery since then. Therefore, the examined data included two consecutive patient cohorts: those who were operated without the CS (non-CS group) and those with it (CS group). Both elective and emergent cardiac surgeries were included. This included on-pump and off-pump coronary artery bypass grafting (CABG), valve surgery, combination of both, as well as other surgical procedures (e.g. aortic artery dissection surgeries). A standardized anaesthesia protocol was used for all patients. Patients were heparinized at 300 IU/kg heparin to achieve an activated clotting time above 480 s. Cardiopulmonary bypass (CPB) was performed in most of the patients. CPB was performed using the same heart–lung machine (Stockert Sorin SIII; Sorin Biomedica, Milan, Italy) with a centrifugal pump, a 40-lm arterial filter and a priming volume of 30 ml/kg body weight of a crystalloid solution (Plasmalyte, Baxter Healthcare, Deerfield, Illinois, USA). Membrane oxygenator was used in all cases. Both antigrade and retrograde blood cardioplegia were utilized. At the end of the procedure, heparin is reversed with protamine sulphate at a dose of 1 mg/100 IU of heparin. The same CS device (Autolog, Medtronic, Minnesota, USA) was used for all patients who had it used. The CS is routinely used throughout the operation. Processed volume includes all surgically shed blood retrieved from the © 2015 International Society of Blood Transfusion Vox Sanguinis (2015) 109, 280–286
cardiac field as well as residual extracorporeal circuit volume. The CS device was used during full heparinization of the patient and according to the manufacturer recommendations. The collected volume is recovered into the CS reservoir and is processed in a 250-ml centrifuge bowl. Minimum of 600 ml of collection is required for processing the blood by the CS. After plasma removal, the RBC unit is washed with 09% normal saline and is checked for volume, haemoglobin (Hb), haematocrit (Hct) and potassium levels. The concentrated RBCs are collected into a labelled collection bag, and the unit is transfused to the patient using a blood transfusion filter (PALL SQ40SE, Pall Medical, Oss, the Netherlands). Patients undergoing cardiac surgery with CPB have retrieved blood from cardiotomy suction in addition to what is collected for cell salvage. Retrieved volumes via the cardiotomy suction get infused back to the patient intraoperatively without it been processed. All patients were intra-operatively and postoperatively transfused as per a local transfusion protocol. The transfusion protocol was developed by consensus and was implemented in 2008 upon the start of the unit. Intraoperative allogeneic RBC transfusion is performed aiming a Hct level of >23%. All CS group patients are transfused with the salvaged RBCs in the immediate postoperative period. Allogeneic RBCs are transfused perioperatively when the haemoglobin levels fall below 80 g/l, or if there are clinical signs of bleeding. Random donor buffy coat platelets are transfused if signs of bleeding exist with platelet (PLT) count
