Reduction of anti-A and anti-B isoagglutinin titers of group O whole blood units employing an ABO antibody immune adsorption column.

BACKGROUND: Massive hemorrhage is a leading cause of death from trauma. There is growing interest in group O whole blood transfusions to mitigate coagulopathy and hemorrhagic shock. Insufficient availability of low-titer group O whole blood is a barrier to routine use. We tested the efficacy of the Glycosorb® ABO immunoadsorption column to reduce anti-A/B titers in group O whole blood. METHODS: Six group O whole blood units were collected from healthy volunteers, and centrifuged to separate platelet poor plasma. Platelet-poor plasma was filtered through a Glycosorb® ABO antibody immunoabsorption column, then reconstituted to prepare post-filtration whole blood. Anti-A/B titers, CBC, free hemoglobin, and thromboelastography (TEG) assays were performed on pre-and post-filtration whole blood. RESULTS: Mean( ± SEM) anti-A (224 ± 65 pre vs 13 ± 4 post) and anti-B (138 ± 38 pre vs 11 ± 4 post) titers were significantly reduced (p = 0.004) in post-filtration whole blood. No significant changes were detected in CBC, free hemoglobin, and TEG parameters on day 0. Free hemoglobin increased throughout storage (48 mg/dl ± 24 Day 0 vs 73 ± 35 Day 7 vs 96 ± 44 Day 14; p = 0.14). CONCLUSIONS: The Glycosorb® ABO column can significantly reduce anti-A/B isoagglutinin titers of group O whole blood units. Glycosorb® ABO could be employed to provide whole blood with lower risk of hemolysis and other consequences of infusing ABO incompatible plasma. Preparation of group O whole blood with substantially reduced anti-A/B would also increase the supply of low-titer group O whole blood for transfusion.

Evaluation of solvent/detergent-treated plasma safety and efficacy in orthotopic liver transplant and thrombotic thrombocytopenic purpura patients: A single center experience.

BACKGROUND: Solvent/detergent-treated, pooled plasma (SDP) is approved for use in orthotopic liver transplantation (OLT) and thrombotic thrombocytopenic purpura (TTP) patients; however, studies evaluating safety and effectiveness of SDP in these populations are limited. METHODS: This prospective study included two cohorts: OLT patients (n = 40) who received either SDP (n = 20) or FFP (control group) (n = 20), and TTP patients (n = 20) who received either SDP (n = 10) or FFP (control group) (n = 10) throughout hospitalization. Medical, laboratory, and blood bank records were retroactively assessed for both cohorts for differences in clinical outcomes, laboratory values, and transfusion data from admission to discharge. RESULTS: In the OLT cohort, significant changes in AST and ALP were observed in the control group as compared to SDP (p < .05 each), and creatinine levels improved significantly in the SDP group as compared to the control group (p < .05) from admission to discharge. In the TTP cohort, platelet counts were significantly improved within the control and SDP groups from admission to discharge, but there were no significant differences between groups (p = .31). LDH levels improved between admission and discharge for both groups (70% decrease in the control group, p < .001, and 80% decrease in the SDP group, p = .001). There were no significant differences detected in clinical outcomes in either cohort. CONCLUSIONS: As evidenced by the lack of adverse events in either cohort and similar clinical outcomes, we conclude that SDP is comparable in safety and effectiveness to FFP in OLT and TTP patients. Further studies are needed to evaluate the potential for improved safety with SDP.

Comparative risk of pulmonary adverse events with transfusion of pathogen reduced and conventional platelet components.

BACKGROUND: Platelet transfusion carries risk of transfusion-transmitted infection (TTI). Pathogen reduction of platelet components (PRPC) is designed to reduce TTI. Pulmonary adverse events (AEs), including transfusion-related acute lung injury and acute respiratory distress syndrome (ARDS) occur with platelet transfusion. STUDY DESIGN: An open label, sequential cohort study of transfusion-dependent hematology-oncology patients was conducted to compare pulmonary safety of PRPC with conventional PC (CPC). The primary outcome was the incidence of treatment-emergent assisted mechanical ventilation (TEAMV) by non-inferiority. Secondary outcomes included: time to TEAMV, ARDS, pulmonary AEs, peri-transfusion AE, hemorrhagic AE, transfusion reactions (TRs), PC and red blood cell (RBC) use, and mortality. RESULTS: By modified intent-to-treat (mITT), 1068 patients received 5277 PRPC and 1223 patients received 5487 CPC. The cohorts had similar demographics, primary disease, and primary therapy. PRPC were non-inferior to CPC for TEAMV (treatment difference -1.7%, 95% CI: (-3.3% to -0.1%); odds ratio = 0.53, 95% CI: (0.30, 0.94). The cumulative incidence of TEAMV for PRPC (2.9%) was significantly less than CPC (4.6%, p = .039). The incidence of ARDS was less, but not significantly different, for PRPC (1.0% vs. 1.8%, p = .151; odds ratio = 0.57, 95% CI: (0.27, 1.18). AE, pulmonary AE, and mortality were not different between cohorts. TRs were similar for PRPC and CPC (8.3% vs. 9.7%, p = .256); and allergic TR were significantly less with PRPC (p = .006). PC and RBC use were not increased with PRPC. DISCUSSION: PRPC demonstrated reduced TEAMV with no excess treatment-related pulmonary morbidity.

Preoperative anemia management program reduces blood transfusion in elective cardiac surgical patients, improving outcomes and decreasing hospital length of stay.

BACKGROUND: Anemia is an independent risk factor for hospitalization, readmission, prolonged length of stay (LOS), diminished quality of life, and mortality. A multidisciplinary program was implemented to manage anemia preoperatively as a patient blood management (PBM) initiative. METHODS AND MATERIALS: From March 2016 to August 2018, 240 patients were screened for anemia during their preoperative cardiovascular visit. About 52/240 (22%) were found to be anemic and met out inclusion criteria. Also, 45/52 (87%) had iron deficiency anemia and 7 (13%) had anemia without iron deficiency. A similar historical cohort of patients undergoing elective cardiovascular surgery with hemoglobin (Hb) < 12 g/dl from September 2014 to February /2016 (n = 52) served as control group. The primary outcome was perioperative red blood cell (RBC) transfusion. Secondary outcomes were date-of-surgery Hb, intensive care unit (ICU) and hospital LOS, complication rates, and transfusion cost. RESULTS: The two most common treatments were IV iron ± folate (n = 36/45; 80%) and oral iron (n = 9/45; 20%). As compared to historical patients, study patients had significantly higher day-of-surgery Hb (10.6 ± 1.4 vs. 9.8 ± 1.3 g/dl, p < .001), lower utilization of RBC transfusion (0.86 ± 1.4 vs. 2.78 ± 2.4, p < .001), fewer days in the ICU (2.1 ± 2.0 vs. 4.0 ± 3.5, p = .002), and shorter total LOS (6.9 ± 4.8 vs. 12.9 ± 6.8, p < .0001). Study patients also showed lower overall complication rates (p < .0001). Analysis of RBC acquisition cost and transfusion cost also showed significant saving of 69% ($293 vs. $945 and $656 vs. $2116, respectively). CONCLUSION: When corrected for type of procedures and surgeon, our pilot anemia program in elective cardiovascular surgeries showed higher day-of-surgery Hb and significant reduction in RBC transfusion rates, ICU and hospital LOS, and overall complication rates.

Whole blood haemostatic function throughout a 28-day cold storage period: an in vitro study.

BACKGROUND: In recent years, there has been renewed interest in whole blood (WB) transfusion, particularly in damage control resuscitation, in part due to the ability to provide the adequate ratio of blood components in a single transfusion. However, there is insufficient evidence to suggest that WB units maintain their haemostatic function during storage, which could compromise their quality and efficacy if transfused. Here, we evaluate the in vitro haemostatic function of stored WB units over a 28-day refrigeration period. METHODS: Standard WB units were collected from healthy volunteers and stored at 4°C for 28 days. Samples were collected from each unit on several days throughout the storage period and tested for complete blood count (CBC), WB aggregation, clot kinetics as measured by thromboelastography (TEG), closure time and plasma-free haemoglobin. RESULTS: Throughout the storage period, there were gradual, significant decreases in platelet count and function, including WB aggregation in response to collagen (P < 0·05) and closure time with epinephrine (P < 0·0005). Plasma-free haemoglobin increased substantially (by 163%) throughout the storage period. However, TEG results remained relatively stable for 3 weeks, indicating possible preservation of haemostatic function during that time. CONCLUSION: This study shows that clot kinetics (as measured by TEG) in WB units stored at 4°C are preserved for up to 21 days. However, high levels of free haemoglobin raise concern for the potential risks of transfusing stored WB. Clinical studies are required to evaluate optimal storage times and outcomes of patients resuscitated with WB as compared to blood components.

Anticoagulant Reversal in Gastrointestinal Bleeding: Review of Treatment Guidelines.

BACKGROUND: Patients receiving anticoagulant therapies, such as vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs), commonly experience gastrointestinal (GI) bleeding as a complication and may require anticoagulant reversal prior to endoscopic treatment. Anticoagulant reversal agents include prothrombin complex concentrates (PCCs; including 3 or 4 coagulation factors), plasma, vitamin K, and target-specific DOAC reversal agents (e.g., idarucizumab and andexanet alfa). AIM: To review current US, as well as international, guidelines for anticoagulant reversal agents in patients on VKAs or DOACs presenting with GI bleeding prior to endoscopy, guideline-based management of coagulation defects, timing of endoscopy, and recommendations for resumption of anticoagulant therapy following hemostasis. Supporting clinical data were also reviewed. METHODS: This is a narrative review, based on PubMed and Internet searches reporting GI guidelines and supporting clinical data. RESULTS: GI-specific guidelines state that use of reversal agents should be considered in patients with life-threatening GI bleeding. For VKA patients presenting with an international normalized ratio > 2.5, guidelines recommend PCCs (specifically 4F-PCC), as they may exhibit greater efficacy/safety compared with fresh frozen plasma in reversal of VKA-associated GI bleeding. For DOAC patients, most guidelines recommend targeted specific reversal agents in the setting of GI bleeding; however, PCCs (primarily 4F-PCC) are often listed as another option. Resumption of anticoagulant therapy following cessation of GI bleeding is also recommended to reduce risks of future thromboembolic complications. CONCLUSIONS: The utility of anticoagulant reversal agents in GI bleeding is recognized in guidelines; however, such agents should be reserved for use in truly life-threatening scenarios.

In Vitro and In Vivo Comparison of Hemoglobin and Electrolytes Following the Collection of Cell Saver Blood Washed with Either Normal Saline or Plasma-Lyte A.

Cell saver blood is typically washed with normal saline (NS); however, recent studies have reported decreased red blood cell hemolysis and increased platelet function when a more physiologic washing solution, such as Plasma-Lyte A (PL-A) is used. We evaluated the in vitro and in vivo effects of NS compared to PL-A as washing solutions for cell saver blood in pediatric cardiac surgery. Cell saver blood was re-infused for up to 24 hours post-collection. Laboratory and clinical data were collected from infants receiving cell saver washed with either NS (n = 20) or PL-A (n = 21). Compositions of the cell saver blood were compared between groups at 5 in vitro time points and in vivo patient blood at 24 hours post-bypass. Although there were differences in in vitro laboratory values between groups; 24 hours post-bypass, in vivo results were similar. Our data supports 24-hour reinfusion of cell saver washed with either NS versus PL-A in pediatric cardiac surgery patients, and provides data on the differences in cell saver composition to guide future studies.

Evaluation of the procoagulant properties of a newly developed platelet modified lysate product.

BACKGROUND: Platelet transfusion is associated with logistical problems with the national storage guidelines of platelets. This results in decreased function in vivo as a result of the platelet storage lesion, and complications such as allergic or hemolytic reactions and thrombosis. We evaluated a new, freshly prepared platelet modified lysate (PML) product designed to be more procoagulant than fresh and stored platelets. METHODS: Fresh platelets were concentrated, sonicated, and centrifuged to produce PML. Samples of both washed and unwashed PML were evaluated for particle size, concentration, and activity, and then tested for clot kinetics and thrombin generation. PML samples were also stored at various temperatures for durations up to 6 months and evaluated for clot kinetics and thrombin generation throughout. RESULTS: PML showed significantly higher concentration of platelet microparticles, increased procoagulant properties, and increased thrombin generation as compared to fresh and stored platelets. In addition, PML maintained its clot kinetics over a 6-month storage period with variable storage conditions. CONCLUSIONS: The newly proposed PML product is more procoagulant, stable, and has additional potential applications than currently available platelet products. Further studies will be performed to assess its functions in vivo and to assess thrombotic potential.

Total plasma heme concentration increases after red blood cell transfusion and predicts mortality in critically ill medical patients.

BACKGROUND: Relationships between red blood cell (RBC) transfusion, circulating cell-free heme, and clinical outcomes in critically ill transfusion recipients are incompletely understood. The goal of this study was to determine whether total plasma heme increases after RBC transfusion and predicts mortality in critically ill patients. STUDY DESIGN AND METHODS: This was a prospective cohort study of 111 consecutive medical intensive care patients requiring RBC transfusion. Cell-free heme was measured in RBC units before transfusion and in the patients' plasma before and after transfusion. RESULTS: Total plasma heme levels increased in response to transfusion, from a median (interquartile range [IQR]) of 35 (26-76) µmol/L to 47 (35-73) µmol/L (p < 0.001). Posttransfusion total plasma heme was higher in nonsurvivors (54 [35-136] µmol/L) versus survivors (44 [31-65] µmol/L, p = 0.03). Posttransfusion total plasma heme predicted hospital mortality (odds ratio [95% confidence interval] per quartile increase in posttransfusion plasma heme, 1.76 [1.17-2.66]; p = 0.007). Posttransfusion total plasma heme was not correlated with RBC unit storage duration and weakly correlated with RBC unit cell-free heme concentration. CONCLUSIONS: Total plasma heme concentration increases in critically ill patients after RBC transfusion and is independently associated with mortality. This transfusion-associated increase in total plasma heme is not fully explained by RBC unit storage age or cell-free heme content. Additional studies are warranted to define mechanisms of transfusion-related plasma heme accumulation and test prevention strategies.

Effect of vitamin K administration on rate of warfarin reversal.

BACKGROUND: Vitamin K is reported to begin reversing warfarin within 6 to 12 hours, but this may occur sooner. We sought to determine the rate of international normalized ratio (INR) reversal following vitamin K and relationships with dose, route, and baseline INR. METHODS: We evaluated adult patients receiving vitamin K monotherapy for warfarin reversal. Post-vitamin K INRs through 48 hours were collected. Relationships between vitamin K dose and route and baseline INR on rate of reversal and complete reversal (INR < 1.5) were evaluated. Assessment was performed graphically using scatter plots with a line of best fit and a counting process model to determine variables associated with achieving complete reversal. RESULTS: A total of 469 post-vitamin K INRs from 235 patients were included. Time to first INR follow-up after vitamin K administration averaged 10.5 ± 4.2 hours. A significant decrease was detected in INR values in comparison to the baseline INR (3.0 ± 1.9 vs. 4.7 ± 2.2; p < 0.01). Rapid and steady INR change began immediately after vitamin K administration (0-4 hr). A high vitamin K dose and intravenous route were associated with rapid INR change and complete reversal (Vitamin K 10 mg [hazard ratio, 2.4; 95% confidence interval, 1.4-4.2] and IV route [hazard ratio, 1.8; 95% confidence interval, 1.3-2.6]); however, overall complete reversal at 24 and 48 hours was low (14.5% and 41.7%, respectively). Higher baseline INR was associated with rapid INR change and lower baseline INR with complete reversal. CONCLUSION: Vitamin K alone starts to reverse warfarin immediately. High vitamin K doses and intravenous route are associated with faster INR reversal. Baseline INR also influences rate of correction and frequency of achieving complete reversal.

Sickle red blood cells are more susceptible to in vitro haemolysis when exposed to normal saline versus Plasma-Lyte A.

BACKGROUND: Normal saline has been the fluid of choice for resuscitation, rehydration and fluid replacement during plasma or red cell exchange/cytapheresis. There are increased concerns about its clinical effects and data showing it causes more haemolysis in vitro than buffered solutions such as Plasma-Lyte A. METHODS: We investigated whether normal saline or Plasma-Lyte A was associated with greater haemolysis during hours of in vitro incubation with both normal red cells and samples from patients with sickle cell anaemia. RESULTS: Sickle red cells haemolysed more than normal red cells did in both crystalloid solutions. The results of 24-hour exposure to saline were particularly striking (median of 163 mg/dl (IQ range 105-247) for sickle red cells vs. 53 (48-92) for normal red cells (P < 0·0001). In patient samples containing variable quantities of haemoglobin S red cells, increased haemoglobin S was associated with increased haemolysis. This effect was greater for normal saline than Plasma-Lyte A (P = 0·12). CONCLUSIONS: These in vitro models demonstrate that short-term ex vivo exposure of sickle red cells to normal saline leads to greater haemolysis than short-term exposure of normal red cells, and this effect is exacerbated by normal saline. Whether use of normal saline causes increased haemolysis in vivo is unknown. Given recent evidence that normal saline increases renal failure and mortality in critically ill patients, further studies are urgently needed.

Placental Chorionic Cyst Fluid Has Prothrombotic Properties and Differs From Amniotic Fluid.

INTRODUCTION: Chorionic cysts of the chorion laeve, fetal chorionic plate, septum, and free membranes have been associated with placental hypoxia, but they have no clear clinical significance. Although immunohistochemistry has identified fibronectin and collagen IV in cyst fluid, the contents have yet to be fully characterized. METHODS: Placental chorionic cysts (N = 10) were sampled by fluid extraction and hemotoxylin and eosin-stained sections. Amniotic fluid samples (N = 8) were obtained from pregnant women who had cytogenetic evaluation. The content of the cysts was tested for thrombogenicity using thromboelastography. The cyst content was tested by Luminex multiplex and ELISA assays and for known prothrombotic and proinflammatory factors. RESULTS: We identified cysts, especially those in the chorionic plate, adjacent to intervillous thrombi with apparent cyst rupture. Thromboelastography revealed a significantly shorter R time compared to whole blood control samples. Concentration of creatinine, α-fetoprotein, and surfactant D in the cyst fluid differed significantly from amniotic fluid. Cyst fluids had a significantly higher expression of all prothrombotic and some proinflammatory factors. DISCUSSION: Our data provide the first evidence that chorionic cyst fluid is prothrombotic and different from amniotic fluid. The association of ruptured cysts with adjacent thrombi and the prothrombotic properties of cyst fluid suggest a causal relationship; however, further studies are needed.

Transfusion medicine: A research agenda for the coming years.

The important scientific and clinical advances of the last century in transfusion medicine include methods for avoiding hemolytic transfusion reactions and preventing transmission of viral infectious diseases. The next great clinical advances will require improving the efficacy and safety of transfusions, as well as acknowledgement of the now proven serious complications of transfusion, including nosocomial infection, thrombosis, inflammation and multi-organ failure. Possible strategies include (1) universal leukoreduction to mitigate transfusion immunomodulation effects and improve storage conditions, (2) minimizing transfusion of ABO incompatible antibodies and cellular/soluble antigens, (3) substituting use of safer solutions for normal saline during apheresis, component infusion and washing (4) new techniques to improve the efficacy and safety of blood components, including improved storage solutions/conditions, supernatant removal by washing, and rejuvenation and (5) maximizing the risk to benefit ratio of transfusions by employing more restrictive and physiologic indications for transfusion (including patient blood management) and improving clinical decision making through novel laboratory and bedside tests such as thromboelastography.

Elevated free hemoglobin and decreased haptoglobin levels are associated with adverse clinical outcomes, unfavorable physiologic measures, and altered inflammatory markers in pediatric cardiac surgery patients.

BACKGROUND: There are data suggesting that free hemoglobin (Hb), heme, and iron contribute to infection, thrombosis, multiorgan failure, and death in critically ill patients. These outcomes may be mitigated by haptoglobin. STUDY DESIGN AND METHODS: 164 consecutively treated children undergoing surgery for congenital heart disease were evaluated for associations between free Hb and haptoglobin and clinical outcomes, physiologic metrics, and biomarkers of inflammation RESULTS: Higher perioperative free Hb levels (and lower haptoglobin levels) were associated with mortality, nosocomial infection, thrombosis, hours of intubation and inotropes, increased interleukin-6, peak serum lactate levels, and lower nadir mean arterial pressures. The median free Hb in patients without infection (30 mg/dL; 29 interquartile range [IQR], 24-52 mg/dL) was lower than in those who became infected (39 mg/dL; IQR, 33-88 mg/ 31 dL; p = 0.0046). The median mechanical ventilation requirements were 19 (IQR, 7-72) hours in patients with higher levels of haptoglobin versus 48 (IQR, 18-144) hours in patients with lower levels (p = 0.0047). Transfusion dose, bypass duration, and complexity of surgery were all significantly correlated with Hb levels and haptoglobin levels. Multivariate analyses demonstrated that these variables were independently and significantly associated with outcomes. CONCLUSIONS: Elevated pre- and postoperative levels of free Hb and decreased levels of haptoglobin were associated with adverse clinical outcomes, inflammation, and unfavorable physiologic metrics. Transfusion, RACHS score, and duration of bypass were associated with increased free Hb and decreased haptoglobin. Further investigation of the role of hemolysis and haptoglobin as potential mediators or markers of outcomes is warranted.

0.9% NaCl (Normal Saline) - Perhaps not so normal after all?

Crystalloid infusion is widely employed in patient care for volume replacement and resuscitation. In the United States the crystalloid of choice is often normal saline. Surgeons and anesthesiologists have long preferred buffered solutions such as Ringer's Lactate and Plasma-Lyte A. Normal saline is the solution most widely employed in medical and pediatric care, as well as in hematology and transfusion medicine. However, there is growing concern that normal saline is more toxic than balanced, buffered crystalloids such as Plasma-Lyte and Lactated Ringer's. Normal saline is the only solution recommended for red cell washing, administration and salvage in the USA, but Plasma-Lyte A is also FDA approved for these purposes. Lactated Ringer's has been traditionally avoided in these applications due to concerns over clotting, but existing research suggests this is not likely a problem. In animal models and clinical studies in various settings, normal saline can cause metabolic acidosis, vascular and renal function changes, as well as abdominal pain in comparison with balanced crystalloids. The one extant randomized trial suggests that in very small volumes (2 l or less) normal saline is not more toxic than other crystalloids. Recent evidence suggests that normal saline causes substantially more in vitro hemolysis than Plasma-Lyte A and similar solutions during short term storage (24 hours) after washing or intraoperative salvage. There are now abundant data to raise concerns as to whether normal saline is the safest replacement solution in infusion therapy, red cell washing and salvage, apheresis and similar uses. In the USA, Plasma-Lyte A is also FDA approved for use with blood components and is likely a safer solution for these purposes. Its only disadvantage is a higher cost. Additional studies of the safety of normal saline for virtually all current clinical uses are needed. It seems likely that normal saline will eventually be abandoned in favor of safer, more physiologic crystalloid solutions in the coming years.

Implementation of a Standardized Transfusion Protocol for Cardiac Patients Treated With Venoarterial Extracorporeal Membrane Oxygenation Is Associated With Decreased Blood Component Utilization and May Improve Clinical Outcome.

BACKGROUND: Extracorporeal membrane oxygenation supplies oxygenated blood to the body supporting the heart and lungs. Survival rates of 20% to 50% are reported among patients receiving ECMO for cardiac arrest, severe cardiogenic shock, or failure to wean from cardiopulmonary bypass following cardiac surgery. Bleeding is one of the most common complications in ECMO patients due to coagulopathy, systemic anticoagulation, and the presence of large bore cannulas at systemic pressure. Absence of a standardized transfusion protocol in this population leads to inconsistent transfusion practices. Here, we assess a newly developed dedicated transfusion protocol in this clinical setting. METHODS: Data were retrospectively reviewed for the first 30 consecutive cardiac ECMO patients prior and post implementation of the ECMO transfusion protocol. Diagnoses, laboratory results, blood component utilization, and outcomes were collected and analyzed. RESULTS: Comorbidities were similar between the 2 eras, as well as the pre-ECMO ejection fraction (P = .568) and duration on ECMO (P = .278). Transfusion utilization data revealed statistically significant decreases in almost all blood components and a savings in blood component acquisition costs of 51% ($175, 970). In addition, an almost 2-fold increase in survival rate was observed in the post-ECMO transfusion protocol era (63% vs 33%; relative risk = 1.82; 95% confidence interval, 1.07-3.10; P = .028). CONCLUSIONS: Our data indicate that implementation of a standardized transfusion protocol, using more restrictive transfusion indications in cardiac ECMO patients, was associated with reduced blood product utilization, decreased complications, and improved survival. This multidepartmental approach facilitates better communication and adherence to consensus clinical decision making between intensive care unit, surgery, and transfusion service and optimizes care of complicated and acutely ill patients.

Oxidation Reduction Potential (ORP) is Predictive of Complications Following Pediatric Cardiac Surgery.

Oxidation reduction potential (ORP) or Redox is the ratio of activity between oxidizers and reducers. Oxidative stress (OS) can cause cellular injury and death, and is important in the regulation of immune response to injury or disease. In the present study, we investigated changes in the redox system as a function of cardiopulmonary bypass (CPB) in pediatric patients. 664 plasma samples were collected from 162 pediatric patients having cardiac surgery of various CPB times. Lower ORP values at 12 h post-CPB were associated with poor survival rate (mean ± SD 167 ± 20 vs. 138 ± 19, p = 0.005) and higher rate of thrombotic complications (153 ± 21 vs. 168 ± 20, p < 0.008). Similarly, patients who developed infections had lower ORP values at 6 h (149 ± 19 vs. 160 ± 22, p = 0.02) and 12 h (156 ± 17 vs. 168 ± 21, p = 0.004) post-CPB. Patients that developed any post-operative complication also had lower 6 h (149 ± 17 vs. 161 ± 23, p = 0.002) and 12 h (157 ± 18 vs. 170 ± 21, p = 0.0007) post-CPB ORP values. Free hemoglobin and IL-6, IL-10, and CRP were not associated with ORP levels. However, higher haptoglobin levels preoperatively were protective against decreases in ORP. Decreased ORP is a marker for poor outcome and predictive of post-operative thrombosis, infection, and other complications in critically ill pediatric cardiac surgery patients. These results suggest that redox imbalance and OS may contribute to the risk of complications and poor outcome in pediatric CBP patients. Haptoglobin may be a marker for increased resilience to OS in this population.