Units Of Packed Red Blood Cells Research Articles

Impact of Packed Red Blood Cell and Platelet Transfusions in Patients Undergoing Dissection Repair

BackgroundTransfusion of blood products commonly occur in patients undergoing repair of acute type A aortic dissection (AADA). Materials and methodsThe medical records of 102 AADA patients were retrospectively reviewed and stratified into cohorts by packed red blood cell (PRBC) and platelet units received: PRBC ≤2 units (n = 68) versus PRBC >2 units (n = 34); platelets ≤1 unit (n = 74) versus platelets >1 unit (n = 28). Continuous and categorical variables were assessed by analysis of variance testing and chi-square or Fisher's testing as appropriate. Multivariate logistic regression was applied to derive P values for post-transfusion complications. Kaplan–Meier survival analyses were used to compare the hospital length of stay (LOS) and survival rate at 1 mo and 1 y. ResultsPatients receiving >2 units of PRBC had a median LOS of 14 d versus 9 d for those receiving ≤2 units (P < 0.002). Transfusion of >2 units of PRBC was a risk factor for postoperative infection (odds ratio [OR] = 5.4, 95% confidence interval [CI]: 1.5-19.0, P = 0.009). Survival at 1 mo was 91% versus 94% (P = 0.783) and 1 y survival was 82% versus 93% (P = 0.269) between the two groups. Patients receiving >1 unit of platelets had a median LOS of 15 d versus 10 d for those receiving ≤1 unit (P = 0.005). Transfusion of >1 unit of platelets was a risk factor for postoperative atrial fibrillation and acute kidney injury (OR = 2.9, 95% CI: 1.1-7.6, P = 0.031; OR = 3.3, 95% CI: 1.2-9.4, P = 0.025, respectively). Survival at 1 mo was 93% versus 93% (P = 0.872) and 1 y survival was 81% versus 92% (P = 0.582) between the two groups. ConclusionsTransfusion of PRBC and platelets above a threshold increases the incidence of postoperative complications and hospital LOS among patients undergoing repair of AADA.

Bringing Packed Red Blood Cells to the Point of Combat Injury: Are We There Yet?

ObjectiveHemorrhage is the leading cause of injury-related prehospital mortality. We investigated worst-case scenarios and possible requirements of the Turkish military. As we plan to use blood resources during casualty transport, the impact of transport-related mechanical stress on packed red blood cells (PRBCs) was analyzed.Materials and MethodsThe in vitro experiment was performed in the environmental test laboratories of ASELSAN®. Operational vibrations of potential casualty transport mediums such as Sikorsky helicopters, Kirpi® armored vehicles, and the NATO vibration standard MIL-STD-810G software program were recorded. The most powerful mechanical stress, which was created by the NATO standard, was applied to 15 units of fresh (≤7 days) and 10 units of old (>7 days) PRBCs in a blood cooler box. The vibrations were simulated with a TDS v895 Medium-Force Shaker Device. On-site blood samples were analyzed at 0, 6, and 24 h for biochemical and biomechanical analyses.ResultsThe mean (±standard deviation) age of fresh and old PRBCs was 4.9±2.2 and 32.8±11.8 days, respectively. Six-hour mechanical damage of fresh PRBCs was demonstrated by increased erythrocyte fragmentation rates (p=0.015), hemolysis rates (p=0.003), and supernatant potassium levels (p=0.003) and decreased hematocrit levels (p=0.015). Old PRBC hemolysis rates (p=0.015), supernatant potassium levels (p=0.015), and supernatant hemoglobin (p=0.015) were increased and hematocrit levels were decreased (p=0.015) within 6 h. Two (13%) units of fresh PRBCs and none of the old PRBCs were eligible for transfusion after 6 h of mechanical stress.ConclusionWhen an austere combat environment was simulated for 24 h, fresh and old PRBC hemolysis rates were above the quality criteria. Currently, the technology to overcome this mechanical damage does not seem to exist. In light of the above data, a new national project is being performed.

Implementation of a Massive Transfusion Protocol: Evaluation of Its Use and Efficacy

Massive transfusion protocols (MTPs) allow practitioners to follow a prescribed algorithm for the rapid replacement of blood products during a massive hemorrhage. They function as an established protocol to provide consistent treatment. Once implemented, the MTP must be evaluated to ensure best practice. The purpose of this clinical improvement project was to formally evaluate the use and efficacy of an MTP during its first year of implementation. The specific aims were to (1) determine whether MTP activations were missed; (2) compare outcomes between those patients managed by the MTP and those who were not; and (3) provide recommendations to the institution's stakeholders. A retrospective medical record review was conducted with 101 electronic medical records of adult trauma patients treated over 1 year. Patients were identified to have experienced massive bleeding if their medical record contained 1 of 4 indicators: (1) transfusion of uncrossmatched blood; (2) tranexamic acid administration; (3) transfusion of 4 or more units of packed red blood cells (PRBCs) in 1 hr; and/or (4) transfusion of 10 or more units of PRBCs in 24 hr. While 58 patients experienced massive bleeding, only 16 (28%) were managed using the MTP. Although the non-MTP group received fewer transfused blood products due to higher initial and 24-hr hemoglobin levels, more deaths occurred in this group than in the MTP group. The recommendations were to (1) establish well-defined criteria for MTP activation based on the 4 indicators of massive bleeding and (2) regularly evaluate the use and efficacy of the MTP to ensure positive patient outcomes.

External validation of a smartphone app model to predict the need for massive transfusion using five different definitions

Previously, a model to predict massive transfusion protocol (MTP) (activation) was derived using a single-institution data set. The PRospective, Observational, Multicenter, Major Trauma Transfusion database was used to externally validate this model's ability to predict both MTP activation and massive transfusion (MT) administration using multiple MT definitions. The app model was used to calculate the predicted probability of MTP activation or MT delivery. The five definitions of MT used were: (1) 10 units packed red blood cells (PRBCs) in 24 hours, (2) Resuscitation Intensity score ≥ 4, (3) critical administration threshold, (4) 4 units PRBCs in 4 hours; and (5) 6 units PRBCs in 6 hours. Receiver operating curves were plotted to compare the predicted probability of MT with observed outcomes. Of 1,245 patients in the data set, 297 (24%) met definition 1, 570 (47%) met definition 2, 364 (33%) met definition 3, 599 met definition 4 (49.1%), and 395 met definition 5 (32.4%). Regardless of the outcome (MTP activation or MT administration), the predictive ability of the app model was consistent: when predicting activation of the MTP, the area under the curve for the model was 0.694 and when predicting MT administration, the area under the curve ranged from 0.695 to 0.711. Regardless of the definition of MT used, the app model demonstrates moderate ability to predict the need for MT in an external, homogenous population. Importantly, the app allows the model to be iteratively recalibrated ("machine learning") and thus could improve its predictive capability as additional data are accrued. Diagnostic test study/Prognostic study, level III.

Abstract TMP90: Prevention of Stroke in Traumatic Cerebrovascular Injury With Aspirin Carries an Increased Risk of Transfusion

Introduction: Traumatic extracranial carotid or vertebral artery injury (TCVI) occurs in about 1% of all blunt trauma admissions, carries a 10% risk of thromboembolic ischemic stroke, and accounts for up to 2,400 strokes annually in the U.S. Screening CT angiography (CTA) of trauma patients is ubiquitous, and patients with initially asymptomatic TCVI are commonly treated with antiplatelet agents to prevent stroke. Although prophylaxis with these agents is thought to be safer than anticoagulation, which carries a sgnificant risk of hemorrhage in trauma patients, their risk of hemorrhagic complications is unknown. Methods: Single-center retrospective cohort study of patients with a screening CTA after admission for blunt trauma. Patients with CTA indicating TCVI were treated routinely with aspirin 325 mg daily. Risk of transfusion ≥1 unit of packed red blood cells (PRBC) &gt;24 hours after admission (excluding transfusions during injury-related blood loss) was assessed according to CTA findings (CTA+ or CTA-) and whether the patient was treated with aspirin (ASA+ or ASA-). Cox proportional hazards regression assuming equal time at risk was used to estimate risk ratios (RRs) and the relative excess risk due to interaction (RERI) for comparing risk of transfusion among the CTA/ASA groups. Results: The mean overall number of units of PRBC was 0.9±2.1 for CTA+/ASA+ patients (n=196) and 0.3±1.60 for CTA-/ASA- patients (n=2290) (&lt;0.0001). When adjusting for age, ISS, and INR ≥1.2 at admission, the overall RR of transfusion was 1.81 (95% CI 1.40-2.35) for CTA+/ASA+ patients compared to CTA-/ASA- patients. Among age groups, CTA+/ASA+ patients ages 50-69 years had the greatest RR (1.91 CI [1.21-3.03]) compared to CTA-/ASA- patients. Conclusion: Use of aspirin to prevent stroke in patients with TCVI carries a significantly increased risk of PRBC transfusion. Future studies are needed to determine if this increased risk of transfusion is offset by a reduced risk of ischemic stroke.

A Sudden Clotting Dilemma: A Case Report of Acquired Factor VIII Deficiency

SESSION TITLE: Hematology and Oncology Disorders SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Acquired Factor VIII deficiency is rare with estimated incidence 1.3 to 1.5 cases per million populations per year. CASE PRESENTATION: 78-year-old female with history of hypertension and hyperlipidemia presented with intermittent hematuria following a mechanical fall at home 2 weeks prior. Patient complained of weakness, fatigue, and light-headedness. She presented to her physician who referred her to hospital for low Hemoglobin/Hematocrit (Hb g/dL/Hct %). Patient presented with Hb/Hct of 6.4/22.1 and elevated creatinine of 3.26 mg/dL. She received 1 unit of packed red blood cells (PRBC) but Hb continued to drop to 5.5. She was noted to have partial thromboplastin time (PTT) of >200sec with no history of anticoagulation or clotting deficiency. CT scan of abdomen without contrast showed peritoneal and retroperitoneal hemorrhages bilaterally and suspected right renal hemorrhagic products in collecting system with moderate hydronephrosis. She was transferred to intensive care unit for monitoring. Mixing studies were done which showed non correction with pooled normal plasma and increasing with incubation. Rheumatological work up was unremarkable. Patient received multiple units of PRBC, fresh frozen plasma, platelets and 3 units of Recombinant Factor VII with eventual stabilization of Hb/Hct. Bethesda assay was sent and Factor 8 activity was <1%. Patient started on rituximab 600mg x 3 doses with 4th dose as outpatient and prednisone 60mg daily. Repeat CT abdomen showing stable retroperitoneal bleed. Patient was discharged. At 3 month follow up, she remained in remission after completion of Prednisone/Rituximab therapy. DISCUSSION: The approach to treatment for acquired factor VIII deficiency is two-fold. Initially the aim is to stop the potentially life threatening bleeding event and secondarily to reduce the antibody titers to factor VIII. Spontaneous resolution of Factor VIII inhibitors occurs in up to 30% of patients however because average time to spontaneous resolution is 21 months physicians usually recommend immunosuppressive treatment. The use of Rituximab for the treatment of this condition was first reported in 2000 with a single case report. It has been proposed in combination with steroids as a less toxic regimen for persons not able to tolerate other immunosuppressive regimens like cyclophosphamide. When steroids are used alone, patients usually relapse once tapered completely off while retrospective analysis show persons who use combination rituximab and steroids are able to maintain remission when steroids stop. CONCLUSIONS: Combination Rituximab with steroids appears to be a safe first line option especially in older patients who cannot tolerate other regimens. Reference #1: Franchini, M., and G. Lippi. “Acquired Factor VIII Inhibitors”. Blood 112.2 (2008): 250-255. DISCLOSURE: The following authors have nothing to disclose: Yehuda Fuzailov, Janine Harewood, Gabriel Jung No Product/Research Disclosure Information

RISK OF PERI-OPERATIVE BLEEDING AND OUTCOMES DURING LEFT VENTRICULAR ASSIST DEVICE IMPLANTATION

There has been a progressive increase in patients undergoing left ventricular assist device (LVAD) implantation. Bleeding complications remain an important cause of morbidity, mortality and blood product exposure contributes to allosensitization and RV dysfunction in the peri-implant period. Existing data has focused on long-term bleeding complications while rates of peri-operative bleeding are relatively unknown. We assessed factors associated with packed red blood cell (PRBC) transfusion within 30 days peri and post-operatively for patients undergoing initial LVAD implantation and the complications associated with PRBC transfusion. We conducted a retrospective cohort study of patients undergoing initial LVAD implantation between January 1, 2003 until December 31, 2015 at Foothills Medical Centre in Calgary Alberta. We collected demographic information, surgical implant details, hemodynamics, laboratory investigations, rates of PRBC transfusion, and outcomes including intensive care unit (ICU) length of stay (LOS), ventilation duration, and mortality. We performed ordinal multivariate regression analysis to determine factors associated with PRBC transfusion and to assess the association between transfusion and our outcomes. We identified 54 patients, mean age 53.1+/-10.8, undergoing initial surgical LVAD implantation, of which 17 (31.5%) died during follow-up. Patient characteristics are shown in Table 1. A mean of 1.6+/-4.1 units of PRBC was tranfused peri-operatively and 6.7+/-7.6 in the 30 days post-operatively. Nine patients (16.7%) received no PRBC transfusion and 29 patients (53.7%) received more than 4 units of PRBC. In multivariate analysis, higher hemoglobin (adjusted odds ratio (OR) 0.67 per 10 mg/dL, 95% CI 0.49-0.89, p=0.006) and minimally invasive surgery (adjusted OR 0.26, 95% CI 0.08-0.83, p=0.02) were associated with a lower PRBC transfusion requirements while higher creatinine (adjusted OR 1.10, 95% CI 1.02–1.19, p=0.02) was associated with an increase. In a separate model, pre-operative hemoglobin < 110 g/L was associated with a 4-fold increase in PRBC transfusion (adjusted OR 4.7, 95% CI 1.63–13.4, p < 0.01). After correcting for age and sex, higher PRBC transfusion was associated with an increase in ICU LOS (adjusted OR 1.15, 95% CI 1.07-1.24, p < 0.01), and ventilation duration (adjusted OR 1.12, 95%CI 1.05-1.20, p < 0.01 and all-cause mortality (adjusted OR 1.08, 95% CI 1.00-1.16, p=0.05). In patients undergoing LVAD implantation, blood product exposure is common in the peri-operative period. Higher hemoglobin, lower creatinine, and minimally invasive surgery are associated with lower rates of PRBC transfusion. Pre-operative optimization targeting baseline hemoglobin levels and renal function may reduce PRBC transfusion rates.

Blood Products Provided to Patients Receiving Futile Critical Care.

The number of hospitalized patients receiving treatment perceived to be futile is not insignificant. Blood products are valuable resources that are donated to help others in need. We aimed to quantify the amount of blood transfused into patients who were receiving treatment that the critical care physician treating them perceived to be futile. During a 3-month period, critical care physicians in 5 adult intensive care units completed a daily questionnaire to identify patients perceived as receiving futile treatment. Of 1136 critically ill patients, physicians assessed 123 patients (11%) as receiving futile treatment. Fifty-nine (48%) of the 123 patients received blood products after they were assessed to be receiving futile treatment: 242 units of packed red blood cells (PRBCs) (7.6% of all PRBC units transfused into critical care patients during the 3-month study period); 161 (9.9%) units of plasma, 137 (12.1%) units of platelets, and 21 (10.5%) units of cryoprecipitate. Explicit guidelines on the use of blood products should be developed to ensure that the use of this precious resource achieves meaningful goals.

Platelet transfusions reduce fibrinolysis but do not restore platelet function during trauma hemorrhage.

Platelets play a critical role in hemostasis with aberrant function implicated in trauma-induced coagulopathy. However, the impact of massive transfusion protocols on platelet function during trauma hemorrhage is unknown. The aim of this study was to characterize the effects of platelet transfusion on platelet aggregation and fibrinolytic markers during hemostatic resuscitation. Trauma patients enrolled into the prospective Activation of Coagulation and Inflammation in Trauma study between January 2008 and November 2015 who received at least four units of packed red blood cells (PRBCs) were included. Blood was drawn in the emergency department within 2 hours of injury and at intervals after every four units of PRBCs transfused. Platelet aggregation was assessed in whole blood with multiple electrode aggregometry. Plasma proteins were quantified by enzyme-linked immunosorbent assay. Of 161 patients who received four or more PRBCs as part of their initial resuscitation, 44 received 8 to 11 units and 28 received 12 units or more. At each timepoint during bleeding, platelet aggregation was similar in patients who had received a platelet transfusion compared with those who had only received other blood products (p > 0.05 for all timepoints). Platelet transfusion during the four PRBC intervals was associated with a decrease in maximum lysis on rotational thromboelastometry (start of interval, 6% [2-12] vs. end of interval, 2% [0-5]; p = 0.001), an increase in plasminogen activator inhibitor-1 (start of interval, 35.9 ± 14.9 vs. end of interval, 66.7 ± 22.0; p = 0.007) and a decrease in tissue plasminogen activator (start of interval, 26.2 ± 10.5 vs. end of interval, 19.0 +/- 5.1; p = 0.04). No statistically significant changes in these parameters occurred in intervals which did not contain platelets. Current hemostatic resuscitation strategies do not appear to restore platelet aggregation during active hemorrhage. However, stored platelets may attenuate fibrinolysis by providing an additional source of plasminogen activator inhibitor-1. Further investigation into the effects of early platelet transfusion on platelet function, hemostatic, and clinical outcomes during bleeding are warranted. Therapeutic, level III.

Thoracic corpectomy for neoplastic vertebral bodies using a navigated lateral extracavitary approach-a single-center consecutive case series: technique and analysis.

Thoracic myelopathy is often caused by vertebral body fractures resulting from neoplastic conditions, traumatic events, or infectious diseases. One of the preferred procedures for treating it is the lateral extracavitary approach (LECA) with single-level or multilevel decompressive corpectomy and reconstruction. The aim of this retrospective study was to analyze the thoracic lateral extracavitary approach with corpectomy using vertebral body replacement systems (VBR-S) and dorsal reconstruction. Twenty-four patients with metastatic or primary lesions of thoracic vertebrae T2-T12 underwent spinal decompression and ventral column reconstruction with correction of spinal deformity via a LECA. One-level to four-level corpectomies were performed with additional navigated dorsal pedicle screw fixation at an average of two levels above and below the corpectomy lesion. None of the patients received preoperative spinal embolization, and the majority of the patients were admitted to radiotherapy postoperatively. Their mean age was 56years (±15), with a female-to-male sex ratio of 8 to 16. Patients with a minimum follow-up period of 16months were included. The Karnofsky index, preoperative and postoperative numeric rating scale (NRS), and Frankel scale were measured. In addition, intraoperative loss of blood (LOB), units of packed red blood cell (PRBC) transfusions, the duration of the operation, and the hospitalization period were evaluated and correlated with preoperative and postoperative values. The majority of the patients were suffering from metastatic lesions and were treated with a 1 level corpectomy (median 1 level, range 1 to 4). The mean duration of surgery was 288min (±121) and the mean LOB was 1626mL (±1486mL), with approximately two PRBC units per patient used. All patients were transferred to the intensive care unit (ICU) postoperatively, with a mean ICU stay of 2.0days (±1day). The mean hospitalization period was 13days (±7days). No implant-related failures or procedure-related deaths were observed. Significant differences were noted between the preoperative and postoperative Karnofsky index (74 vs. 84%) and NRS (4 vs. 2). One patient required revision surgery due to a superficial wound infection, and another needed revision surgery due to a dural tear. In another patient, an iatrogenic dural tear was repaired during the same surgical procedure and did not lead to postoperative complications. Four pleural effusions and one pneumothorax were observed, so that the overall complication rate was approximately 33%. Four of the patients died within 2years of the operation due to progression of the primary disease. Lateral corpectomy and sagittal reconstruction of the thoracic spine using VBR-S conducted via a navigated LECA approach yields favorable results, despite the burden of neoplastic disease. These challenging procedures are accompanied by increased LOB and hospitalization periods, with moderate transfusion requirements. Surgery-related complications are low and local tumor control is satisfactory, despite the progression of the underlying neoplastic disease. However, optimal surgical therapy does not ensure long-term survival.Study design Retrospective analysis of thoracic corpectomiesLevel of evidence 4.

The cost of transfusing a unit of red blood cells: a costing model for Canadian hospital use

BackgroundNo direct and thorough accounting of costs related to packed red blood cells (PRBCs) has occurred in recent Canadian history. Our study sought to determine the cost accrued for a unit of PRBC within a Canadian hospital related to the inventory management, storage, testing, issuing and administration of the product.MethodsAn eight‐step costing model was developed to capture associated costs from the time of receipt at the hospital to the time of transfusion to a patient. Personnel, consumables and capital equipment costs within each step of the model were assessed using activity‐based accounting methods and German cost accounting principles.ResultsBased on 10,475 units, total in‐hospital cost per unit of PRBC was $243·10. Personnel, consumables and capital costs contributed 77·54%, 19·86% and 2·60% to this cost, respectively.ConclusionThis study's in‐hospital costs of $243·10 summed with the $423·00 acquisition costs per unit PRBC from the blood supplier place the complete societal costs of one unit PRBCs at $666·10. This value is comparable, but lower than the majority of studies in the United States and Europe examining the societal costs of PRBCs.

Prognostic effect of different blood transfusion ratios in trauma patients with massive transfusion

Objective To evaluate the prognostic effect of different ratios of fresh frozen plasma (FFP) to packed red blood cells (PRBC) in massively transfused trauma patients. Methods A retrospective cohort study was conducted for 210 trauma patients who received more than 10 units of PRBC during the initial 24 hours from January 2007 to June 2015. The patients were divided into four groups: Group A(PRBC ∶FFP≤1, n=41), Group B (1 2, n=76). At 24 hours after admission, blood transfusion amount, blood transfusion ratios, post-transfusion adverse reactions (allergy, non-hemolytic febrile transfusion reaction, hemolysis, congestive heart failure, pulmonary edema, etc) and coagulation changes [hemoglobin (Hb), platelet count (PC), prothrombin time(PT), activated partial thromboplastin time(APTT), international normalized ratio (INR), etc] were compared among groups. Prognostic markers including sequential organ failure assessment(SOFA), hospital stay, ICU stay, 30-day mortality and causes of death were also evaluated. Results Use of PRBC was decreased significantly in Group A than in other groups (P 0.05). The coagulation indices (PT, APTT and INR) in Groups A and B were significantly decreased compared to Group D after transfusion (P 0.05). Group D was associated with higher SOFA and higher 30-day mortality than other groups(P 0.05). Meanwhile, ratio of patients died of massive hemorrhage in Group D was also higher than other groups (P<0.01). Kaplan-Meier survival analysis showed the survival interval was the shortest in Group D, while the longest in Group B and C. Conclusions Modest transfusion ratios(1. 5<PRBC ∶FFP≤2)within 24 hours can substantially improve outcomes in trauma patients. Aggressive ratios may improve coagulation indices and reduce use of PRBC, with no more benefit to the outcomes. Key words: Blood component transfusion; Wounds and injuries; Prognosis

Posttransfusion Increase of Hematocrit per se Does Not Improve Circulatory Oxygen Delivery due to Increased Blood Viscosity.

Blood transfusion is used to treat acute anemia with the goal of increasing blood oxygen-carrying capacity as determined by hematocrit (Hct) and oxygen delivery (DO2). However, increasing Hct also increases blood viscosity, which may thus lower DO2 if the arterial circulation is a rigid hydraulic system as the resistance to blood flow will increase. The net effect of transfusion on DO2 in this system can be analyzed by using the relationship between Hct and systemic blood viscosity of circulating blood at the posttransfusion Hct to calculate DO2 and comparing this value with pretransfusion DO2. We hypothesized that increasing Hct would increase DO2 and tested our hypothesis by mathematically modeling DO2 in the circulation. Calculations were made assuming a normal cardiac output (5 L/min) with degrees of anemia ranging from 5% to 80% Hct deficit. We analyzed the effects of transfusing 0.5 or more units of 300 cc of packed red blood cells (PRBCs) at an Hct of 65% and calculated microcirculatory DO2 after accounting for increased blood viscosity and assuming no change in blood pressure. Our model accounts for O2 diffusion out of the circulation before blood arriving to the nutritional circulation and for changes in blood flow velocity. The immediate posttransfusion DO2 was also compared with DO2 after the transient increase in volume due to transfusion has subsided. Blood transfusion of up to 3 units of PRBCs increased DO2 when Hct (or hemoglobin) was 60% lower than normal, but did not increase DO2 when administered before this threshold. After accounting for the effect of increasing blood viscosity on blood flow owing to increasing Hct, we found in a mathematical simulation of DO2 that transfusion of up to 3 units of PRBCs does not increase DO2, unless anemia is the result of an Hct deficit greater than 60%. Observations that transfusions occasionally result in clinical improvement suggest that other mechanisms possibly related to increased blood viscosity may compensate for the absence of increase in DO2.

Temperature-dependent haemolytic propensity of CPDA-1 stored red blood cells vs whole blood - Red cell fragility as donor signature on blood units.

To preserve cellular integrity and avoid bacterial growth, storage and transfer of blood and blood products follow strict guidelines in terms of temperature control. We evaluated the impact of ineligible warming of whole blood donations on the quality of blood components. One-hundred and twenty units of whole blood (WB) from eligible blood donors were collected in CPDA-1 and stored at 4±2 °C. During shipment to the blood processing centre, a gradual warming up to 17 °C was recorded within a period of less than eight hours. The warmed units were processed to packed red blood cells (PRBCs) or stored as WB units at 4±2 °C. In-bag haemolysis, osmotic fragility (mean corpuscular fragility, MCF) and bacterial growth were assessed in blood and blood components throughout the storage period. Normal basal and early storage levels of haemolysis were recorded in both PRBC and WB units. Thereafter, PRBCs exhibited higher average in-bag haemolysis and MCF index compared to the WB units throughout the storage. Moreover, 14.3 and 52.4% of the PRBC units exceeded the upper permissible limit of 0.8% haemolysis at the middle (1.220±0.269%) or late (1.754±0.866%) storage period, respectively. MCF index was similar in all PRBCs at the middle of storage but significantly lower in the non-haemolysed compared to the haemolysed units of PRBCs on the last days. The fragility of stored RBCs was proportional to the donor-related values of day 2 samples (r=0.861, p<10-32). In the qualified PRBCs, MCF was correlated with haemolysis at every time point of the storage period (r=0.332, p<0.050). Bacterial growth was detected by blood culture in two units of PRBCs. Transient, gradient warming of whole blood from 4 to 17 °C led to increased incidence of in-bag haemolysis in PRBC but not in WB units. Haemolysis is a multi-parametric phenotype of stored blood, and MCF is a donor-related and highly dynamic measure that can, in part, predict the storage lesion.

Prothrombin time is predictive of low plasma prothrombin concentration and clinical outcome in patients with trauma hemorrhage: analyses of prospective observational cohort studies

BackgroundFibrinogen and prothrombin have been suggested to become rate limiting in trauma associated coagulopathy. Administration of fibrinogen is now recommended, however, the importance of prothrombin to patient outcome is unknown.MethodsWe have utilized two trauma patient databases (database 1 n = 358 and database 2 n = 331) to investigate the relationship of plasma prothrombin concentration on clinical outcome and coagulation status. Database 1 has been used to assess the relationship of plasma prothrombin to administered packed red blood cells (PRBC), clinical outcome and coagulation biomarkers (Prothrombin Time (PT), ROTEM EXTEM Coagulation Time (CT) and Maximum Clot Firmness (MCF)). ROC analyses have been performed to investigate the ability of admission coagulation biomarkers to predict low prothrombin concentration (database 1), massive transfusion and 24 h mortality (database 1 and 2). The importance of prothrombin was further investigated in vitro by PT and ROTEM assays in the presence of a prothrombin neutralizing monoclonal antibody and following step-wise dilution.ResultsPatients who survived the first 24 h had higher admission prothrombin levels compared to those who died (94 vs.67 IU/dL). Patients with lower transfusion requirements within the first 24 h (≤10 units of PRBCs) also had higher admission prothrombin levels compared to patients with massive transfusion demands (>10 units of PRBCs) (95 vs.62 IU/dL). Admission PT, in comparison to admission ROTEM EXTEM CT and MCF, was found to be a better predictor of prothrombin concentration <60 IU/dL (AUC 0.94 in database 1), of massive transfusion (AUC 0.92 and 0.81 in database 1 and 2 respectively) and 24 h mortality (AUC 0.90 and 0.78 in database 1 and 2, respectively). In vitro experiments supported a critical role for prothrombin in coagulation and demonstrated that PT and ROTEM EXTEM CT are sensitive methods to measure low prothrombin concentration.DiscussionOur analyses suggest that prothrombin concentration at admission is predictive of mortality and transfusion and indicates that prothrombin and fibrinogen are rate limiting in coagulopathy.ConclusionsAdmission PT is predictive of low prothrombin concentration and clinical outcome. PT could therefore be used as a surrogate for prothrombin concentration and further evaluation of point-of-care devices for faster PT analysis is warranted.

Hemostatic Resuscitation in Peripartum Hysterectomy Pre- and Postmassive Transfusion Protocol Initiation.

Background Massive transfusion protocols (MTPs) have been examined in trauma. The exact ratio of packed red blood cells (PRBC) to other blood replacement components in hemostatic resuscitation in obstetrics has not been well defined. Objective The objective of this study was to evaluate hemostatic resuscitation in peripartum hysterectomy comparing pre- and postinstitution of a MTP. Study Design We conducted a retrospective, descriptive study of women undergoing peripartum hysterectomies from January 2002 to January 2015 who received ≥ 4 units of PRBC. Individuals were grouped into either a pre-MTP institution group or a post-MTP institution group. The post-MTP group was subdivided into those who had the protocol activated (MTP) versus not activated (no MTP). Primary outcomes were estimated blood loss (EBL) and need for blood product replacement. The secondary outcome was a composite of maternal morbidity, including need for mechanical ventilation, venous thromboembolism, pulmonary edema, acute kidney injury, and postpartum infection. A Mann-Whitney U test was used to compare continuous variables, and a chi-squared test was used for categorical variables with significance of p < 0.05. Results Of the 165 women who had a peripartum hysterectomy during the study period, 62 received four units or more of PRBC. No significant differences were noted in EBL or blood product replacement between the pre-MTP (n = 39) and post-MTP (n = 23) groups. Similarly, the MTP (n = 6) and no MTP (n = 17) subgroups showed no significant difference between EBL and overall blood product replacement. Significant differences were seen in transfusion of individual blood products, such as fresh frozen plasma (FFP) (MTP = 4, no MTP = 2; p = 0.02) and platelets (plts) (MTP = 6, no MTP = 0; p = 0.03). The use of high ratio replacement therapy for both plasma and plts was more common in the MTP group (FFP/PRBC ratio [MTP = 0.5, no MTP = 0.3; p = 0.02]; plts/PRBC ratio [MTP = 0.7, no MTP = 0; p = 0.03]). There were no differences in the secondary outcome between pre- and post-MTP or MTP and no MTP. Conclusion Initiation of the MTP did result in an increase in transfusion of FFP and plts intraoperatively. At our institution, the MTP is underutilized, but it appears that providers are more cognizant of the use of high transfusion ratios.

Pre-hospital transfusion of packed red blood cells in 147 patients from a UK helicopter emergency medical service

BackgroundEarly transfusion of packed red blood cells (PRBC) has been associated with improved survival in patients with haemorrhagic shock. This study aims to describe the characteristics of patients receiving pre-hospital blood transfusion and evaluate their subsequent need for in-hospital transfusion and surgery.MethodsThe decision to administer a pre-hospital PRBC transfusion was based on clinical judgment. All patients transfused pre-hospital PRBC between February 2013 and December 2014 were included. Pre-hospital and in-hospital records were retrospectively reviewed.ResultsOne hundred forty-seven patients were included. 142 patients had traumatic injuries and 5 patients had haemorrhagic shock from a medical origin. Median Injury Severity Score was 30. 90% of patients receiving PRBC had an ISS of >15. Patients received a mean of 2.4(±1.1) units of PRBC in the pre-hospital phase. Median time from initial emergency call to hospital arrival was 114 min (IQR 103–140). There was significant improvement in systolic (p < 0.001), diastolic (p < 0.001) and mean arterial pressures (p < 0.001) with PRBC transfusion but there was no difference in HR (p = 0.961). Patients received PRBC significantly faster in the field than waiting until hospital arrival. At the receiving hospital 57% required an urgent surgical or interventional radiology procedure. At hospital arrival, patients had a mean lactate of 5.4(±4.4) mmol/L, pH of 6.9(±1.3) and base deficit of −8.1(±6.7). Mean initial serum adjusted calcium was 2.26(±0.29) mmol/L. 89% received further blood products in hospital. No transfusion complications or significant incidents occurred and 100% traceability was achieved.DiscussionPre-hospital transfusion of packed red cells has the potential to improvde outcome for trauma patients with major haemorrhage. The pre-hospital time for trauma patients can be several hours, suggesting transfusion needs to start in the pre-hospital phase. Hospital transfusion research suggests a 1:1 ratio of packed red blood cells to plasma improves outcome and further research into pre-hospital adoption of this strategy is needed.ConclusionPre-hospital PRBC transfusion significantly reduces the time to transfusion for major trauma patients with suspected major haemorrhage. The majority of patients receiving pre-hospital PRBC were severely injured and required further transfusion in hospital. Further research is warranted to determine which patients are most likely to have outcome benefit from pre-hospital blood products and what triggers should be used for pre-hospital transfusion.

Traumatic Abdominal Solid Organ Injury Patients Might Benefit From Thromboelastography-Guided Blood Component Therapy.

BackgroundThromboelastography (TEG) has been utilized for the guidance of blood component therapy (BCT). We aimed to investigate the association between emergent TEG-guided BCT and clinical outcomes in patients with traumatic abdominal solid organ (liver and/or spleen) injuries.MethodsA single center retrospective study of patients who sustained traumatic liver and/or spleen injuries receiving emergent BCT was conducted. TEG was ordered in all these patients. Patient demographics, general injury information, outcomes, BCT, and TEG parameters were analyzed and compared in patients receiving TEG-guided BCT versus those without.ResultsA total of 166 patients were enrolled, of whom 52% (86/166) received TEG-guided BCT. A mortality of 12% was noted among patients with TEG-guided BCT when compared with 19% of mortality in patients with non-TEG-guided BCT (P > 0.05). An average of 4 units of packed red blood cell (PRBC) was received in patients with TEG-guided BCT when compared to an average of 9 units of PRBC received in non-TEG-guided BCT patients (P < 0.01). A longer hospital length of stay (LOS, 19 ± 16 days) was found among non-TEG-guided BCT patients when compared to the TEG-guided BCT group (14 ± 12 days, P < 0.05). TEG-guided BCT showed as an independent factor associated with hospital LOS after other variables were adjusted (coefficiency: 5.44, 95% confidence interval: 0.69 - 10.18).ConclusionsTraumatic abdominal solid organ injury patients receiving blood transfusions might benefit from TEG-guided BCT as indicated by less blood products needed and less hospitalization stay among the cohort.

Physiological and operative severity score for the enumeration of mortality and morbidity scoring systems for assessment of patient outcome and impact of surgeons' and anesthesiologists' performance in hepatopancreaticobiliary surgery.

Context:The physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) is a scoring system used to predict morbidity and mortality.Aims:We compared the physiological and operative risk, the expected morbidity and mortality, and the observed postoperative mortality among patients operated by different surgeons and anesthetized by different anesthesiologists.Settings and Design:This was a retrospective, single center study.Subjects and Methods:The anesthetic records of 159 patients who underwent hepatopancreaticobiliary surgery were analyzed for the physiological and operative severity, POSSUM morbidity, POSSUM and Portsmouth POSSUM (P-POSSUM) mortality scoring systems, observed mortality in 30-days, 3, 6, and 12 months postoperatively, duration of surgery, and units of packed red blood cells (PRBC) transfused. These variables were compared among patients operated by five different surgeons and anesthetized by seven different anesthesiologists.Statistical Analysis:One-way analysis of variance was used for normally and Kruskal–Wallis test for nonnormally distributed responses. Differences in percentages of postoperative mortality were assessed by Chi-squared test.Results:The physiological severity, POSSUM morbidity, POSSUM and P-POSSUM mortality scores, and observed mortality at 1, 3, 6, and 12 months postoperatively did not differ among patients operated by different surgeons and anesthetized by different anesthesiologists. Duration of surgery (P < 0.001), PRBC units transfused (P = 0.002), and operative severity (P = 0.001) differed significantly among patients operated by different surgeons.Conclusions:The physiological severity score, POSSUM and P-POSSUM scores did not differ among patients operated by different surgeons and anesthetized by different anesthesiologists. The different operative severity scores did not influence the observed mortality in the postoperative period.

Hemodiafiltration-A Technique for Physiological Correction of Priming Solution in Pediatric Cardiac Surgery: An In Vitro Study.

Pediatric cardiopulmonary bypass (CPB) circuit invariably requires priming with packed red blood cells (PRBCs). Metabolic composition of stored PRBCs is unphysiological and becomes worse with increasing duration of storage. It is recommended to correct these abnormalities before initiation of CPB. We tested the hypothesis that hemodiafiltration of the prime with 0.45% saline is sufficient for reducing the metabolic load and reaching a physiologic state. In an in vitro study, 100 mL of blood each from 45 units of PRBCs stored for 3-20 days were used for priming the 45 neonatal CPB circuits. Based upon the method used for removal of excess crystalloid from the prime, circuits were divided into three groups. Group 1: Direct removal through manifold line. Group 2: Ultrafiltration of prime. Group 3: Hemodiafiltration of the prime. Blood gas analyses were obtained from the PRBCs and from the prime before and after removal of crystalloid. Both direct removal of crystalloid and ultrafiltration resulted in significant reduction in biochemical and metabolic load of blood (P < 0.001). However, the final composition of the prime was far from being physiological. Hemodiafiltration resulted in improvement of metabolic parameters to near physiological range (lactate: 33.8 ± 4.44 vs. 14 ± 2.53 mg/dL, pH: 7.05 ± 0.15 vs. 7.34 ± 0.06, bicarbonates: 4.83 ± 0.59 vs. 27.6 ± 2.94 meq/L; P < 0.001). Similarly, sodium (147.76 ± 12.73 vs. 144.6 ± 5.96 meq/L) and potassium (9.6 ± 2.83 vs. 4.23 ± 0.37 meq/L) also changed significantly (P < 0.001) to near physiologic range. Hemodiafiltraion of final prime is a simple, efficients and rapid method of correcting the biochemical parameters and reducing the metabolic load of stored PRBCs towards the physiological range before initiating the CPB.