Perioperative coagulation management--fresh frozen plasma

Perioperative fluid management for adult cardiac surgery: network meta-analysis pooling on twenty randomised controlled trials

BACKGROUND

The aim of this study was to evaluate colloids and crystalloids used in perioperative fluid therapy for cardiac surgery patients to further investigate the optimal management strategies of different solutions.

METHOD

RCTs about adult surgical patients allocated to receive perioperative fluid therapy for electronic databases, including Ovid MEDLINE, EMBase, and Cochrane Central Register of Controlled Trials, were searched up to February 15, 2023.

RESULTS

None of the results based on network comparisons, including mortality, transfuse PLA, postoperative chest tube output over the first 24 h following surgery, and length of hospital stay, were statistically significant. Due to the small number of included studies, the results, including acute kidney injury, serum creatinine, serum microglobulin, and blood urea nitrogen, are from the direct comparison. For transfusion of RBCs, significant differences were observed in the comparisons of 3% gelatine vs. 6% HES 200/0.5, 4% albumin vs. 5% albumin, 4% gelatine vs. 5% albumin, 5% albumin vs. 6% HES 200/0.5, and 6% HES 130/0.4 vs. 6% HES 200/0.5. In transfusion of FFP, significant differences were observed in comparisons of 3% gelatine vs. 4% gelatine, 3% gelatine vs. 6% HES 200/0.5, 5% albumin vs. 6% HES 200/0.5, 4% gelatine vs. 5% albumin, 4% gelatine vs. 6% HES 200/0.4, and 6% HES 130/0.4 vs. 6% HES 200/0.5. For urinary output at 24 h after surgery, the results are deposited in the main text.

CONCLUSION

This study showed that 3% gelatin and 5% albumin can reduce the transfuse RBC and FFP. In addition, the use of hypertonic saline solution can increase urine output, and 5% albumin and 6% HES can shorten the length of ICU stay. However, none of the perioperative fluids showed an objective advantage in various outcomes, including mortality, transfuse PLA, postoperative chest tube output over the first 24 h following surgery, and length of hospital stay. The reliable and sufficient evidences on the injury of the kidney, including acute kidney injury, serum creatinine, serum microglobulin, and blood urea nitrogen, was still lacking. In general, perioperative fluids had advantages and disadvantages, and there were no evidences to support the recommendation of the optimal perioperative fluid for cardiac surgery.

Plasma: indications, controversies, and opportunities

Plasma is overused as a blood product worldwide; however, data supporting appropriate use of plasma is scant. Its most common utilization is for treatment of coagulopathy in actively bleeding patients; it is also used for coagulation optimization prior to procedures with specific coagulation profile targets. A baseline literature review in PUBMED and Google Scholar was done (1 January 2000 to 1 June 2023), utilizing the following search terms: plasma, fresh frozen plasma, lyophilized plasma, indications, massive transfusion protocol, liver disease, warfarin reversal, cardiothoracic surgery, INR < 2. An initial review of the titles and abstracts excluded all articles that were not focused on transfusional medicine. Additional references were obtained from citations within the retrieved articles. This narrative review discusses the main indications for appropriate plasma use, mainly coagulation factor replacement, major hemorrhage protocol, coagulopathy in liver disease, bleeding in the setting of vitamin K antagonists, among others. The correlation between concentration of coagulation factors and INR, as well as the proper plasma dosing with its volume being weight-based, is also discussed. A high value approach to plasma utilization is supported with a review of the clinical situations where plasma is overutilized or unnecessary. Finally, a discussion of novel plasma products is presented for enhanced awareness.

Fresh frozen plasma transfusion after cardiac surgery

INTRODUCTION

Fresh frozen plasma (FFP) transfusion in the intensive care unit (ICU) is commonly used to treat coagulopathy and bleeding in cardiac surgery, despite suggestion that it may increase the risk of morbidity and mortality through mechanisms such as fluid overload and infection.

METHODS

We retrospectively studied consecutive adults undergoing cardiac surgery from the Medical Information Mart for Intensive Care III and IV databases. We applied propensity score matching to investigate the independent association of within-ICU FFP transfusion with mortality and other key clinical outcomes.

RESULTS

Of our 12,043 adults who met inclusion criteria, 1585 (13.2%) received perioperative FFP with a median of 2.48 units per recipient (interquartile range [IQR]: 2.04, 4.33) at a median time of 1.83 h (IQR: 0.75, 3.75) after ICU admission. After propensity matching of 952 FFP recipients to 952 controls, we found no significant association between FFP use and hospital mortality (odds ratio (OR): 1.58; 99% confidence interval (CI): 0.57, 3.71), suspected infection (OR: 0.72; 99% CI: 0.49, 1.08), or acute kidney injury (OR: 1.23; 99% CI: 0.91, 1.67). However, FFP was associated with increased days in hospital (adjusted mean difference (AMD): 1.28; 99% CI: 0.27, 2.41; p = .0050), days in intensive care (AMD: 1.28; 99% CI: 0.27, 2.28; p = .0011), and chest tube output in millilitres up to 8 h after transfusion (AMD: 92.98; 99% CI: 52.22, 133.74; p < .0001).

CONCLUSIONS

After propensity matching, FFP transfusion was not associated with increased hospital mortality, but was associated with increased length of stay and no decrease in bleeding in the early post-transfusion period.

Risk factors for postoperative myocardial injury-related cardiogenic shock in patients undergoing cardiac surgery

BACKGROUND

Myocardial injury-related cardiogenic shock (MICS) is significantly associated with poor outcomes in patients after cardiac surgery. Herein, we aimed to investigate the risk factor for postoperative MICS.

METHODS

We performed a case-control study on 792 patients undergoing cardiac surgery from 2016 to 2019, including 172 patients with postoperative MICS and 620 age- and sex-matched controls. MICS was defined as composite criteria: a cardiac index of < 2.2 L/m²/min, arterial lactate levels of > 5 mmol/L at the end of the surgery, a vasoactive-inotropic score of > 40 at the end of the surgery, and a cardiac troponin T (cTnT) level of > 0.8 µg/L on postoperative day 1 (POD1) with an increase of > 10% on POD 2.

RESULTS

A total of 4671 patients who underwent cardiac surgery in our hospital between 2016 and 2019 were included; of these, 172 (3.68%) had MICS and the remaining 4499 did not. For investigating the risk factors, we selected 620 age- and sex-matched controls. In the univariate analysis, MICS was significantly associated with death (P < 0.05), extracorporeal membrane oxygenation (P < 0.05), continuous renal replacement therapy (P < 0.01), and ventricular arrhythmias (P < 0.05). Multivariable logistic regression analysis revealed that diabetes mellitus (OR:8.11, 95% CI: 3.52-18.66, P < 0.05) and a cardiopulmonary bypass (CPB) time of > 2 h (OR: 3.16, 95% CI: 1.94-5.15, P < 0.05) were associated with postoperative MICS. Moreover, long-time administration of preoperative calcium channel blocker (CCB) was associated with a less incidence of MICS (OR: 0.11, 95% CI: 0.05-0.27, P < 0.05).

CONCLUSIONS

Postoperative MICS is significantly associated with poor outcomes. Diabetes mellitus and long CPB time are associated with MICS. Preoperative CCB administration is associated with less incidence of MICS.

Reduced Time to Procedure for Gastrointestinal Bleeding After Warfarin Reversal With Four-Factor Complex Concentrate as Compared to Plasma

Background

Bleeding is a serious adverse effect of vitamin K antagonists (VKAs). Anticoagulation reversal is required in some acute cases. This is usually accomplished by plasma transfusion or four-factor prothrombin complex concentrate (4F-PCC). The aim of this study was to gain insight into the clinical course of patients with gastrointestinal (GI) bleeding who require VKA reversal.

Methods

Medical records were collected from two centers from patients who presented to the emergency department (ED) for GI bleeding and received 4F-PCC or plasma for VKA reversal between January 2015 and December 2020. ED, hospital, intensive care unit (ICU) length of stay (LOS) as well as time from admission to GI procedure were determined.

Results

4F-PCC patients (n = 49) as compared to plasma (n = 63) patients were found to have a greater number of comorbidities (average of 4.2 vs. 2.7 comorbidities/patient) and more ICU admissions (47% vs. 21%). Time to GI procedure was significantly decreased in the 4F-PCC group (median (interquartile range (IQR)) 19.47 (9.23 - 30.25) vs. 27.88 (21.38 - 45.00) h; P = 0.01). When adjusting for comorbidities, differences in time to GI procedures were also significant in favor of 4F-PCC regardless of any comorbidities (P = 0.014), in atrial fibrillation (P = 0.045) and in hypertension (P = 0.02). The 4F-PCC patients had shorter LOS in the ED and ICU.

Conclusions

Our study demonstrated that compared to plasma, 4F-PCC was utilized in more acutely ill patients with higher rates of comorbidities and ICU admission. Nevertheless, the patients who received 4F-PCC had faster access to GI procedure and shorter ED and ICU LOS.

Management of Hemorrhagic Shock: Physiology Approach, Timing and Strategies

Hemorrhagic shock (HS) management is based on a timely, rapid, definitive source control of bleeding/s and on blood loss replacement. Stopping the hemorrhage from progressing from any named and visible vessel is the main stem fundamental praxis of efficacy and effectiveness and an essential, obligatory, life-saving step. Blood loss replacement serves the purpose of preventing ischemia/reperfusion toxemia and optimizing tissue oxygenation and microcirculation dynamics. The "physiological classification of HS" dictates the timely management and suits the 'titrated hypotensive resuscitation' tactics and the 'damage control surgery' strategy. In any hypotensive but not yet critical shock, the body's response to a fluid load test determines the cut-off point between compensation and progression between the time for adopting conservative treatment and preparing for surgery or rushing to the theater for rapid bleeding source control. Up to 20% of the total blood volume is given to refill the unstressed venous return volume. In any critical level of shock where, ab initio, the patient manifests signs indicating critical physiology and impending cardiac arrest or cardiovascular accident, the balance between the life-saving reflexes stretched to the maximum and the insufficient distal perfusion (blood, oxygen, and substrates) remains in a liable and delicate equilibrium, susceptible to any minimal change or interfering variable. In a cardiac arrest by exsanguination, the core of the physiological issue remains the rapid restoration of a sufficient venous return, allowing the heart to pump it back into systemic circulation either by open massage via sternotomy or anterolateral thoracotomy or spontaneously after aorta clamping in the chest or in the abdomen at the epigastrium under extracorporeal resuscitation and induced hypothermia. This is the only way to prevent ischemic damage to the brain and the heart. This is accomplishable rapidly and efficiently only by a direct approach, which is a crush laparotomy if the bleeding is coming from an abdominal +/- lower limb site or rapid sternotomy/anterolateral thoracotomy if the bleeding is coming from a chest +/- upper limbs site. Without first stopping the bleeding and refilling the heart, any further exercise is doomed to failure. Direct source control via laparotomy/thoracotomy, with the concomitant or soon following venous refilling, are the two essential, initial life-saving steps.

The utility and complications of plasma administration in cirrhotic patients undergoing minimally invasive procedures

Patients with cirrhosis have coagulopathy often necessitating correction with blood products, such as plasma products (fresh frozen plasma and plasma frozen within 24 h) prior to certain invasive procedures. However, plasma administration has the potential for substantial negative adverse effects such as volume overload, transfusion-related lung injury and allergic/anaphylactic reactions. In addition, its effectiveness in preventing bleeding is similarly unclear. The purpose of this study was to determine the safety and efficacy of plasma administration in cirrhotic patients undergoing minimally invasive procedures, specifically vascular access placement, transjugular liver biopsies, renal biopsies and thoracenteses. In this retrospective cohort study, we identified patients receiving plasma products in preparation for an invasive procedure, with the primary outcomes of volume overload and bleeding. Of the 145 transfusion events that met the criteria from 2015 to 2018, the median INR decreased from 2.7 to 2.2 pre and post plasma administration and 13.8% of recipients had complications of volume overload. The cost of acquisition of plasma administered below clinically impactful doses accumulates to an estimated 19 000 dollars over this time period, not including nursing preparation or production costs. Plasma products minimally, if at all, improved laboratory values of coagulation and in some patients led to adverse effects.

Anesthesia for the Patient with Severe Liver Failure

The incidence of liver failure continues to increase, and it is associated with increased perioperative morbidity and mortality. Liver failure is associated with multiorgan dysfunction, including central nervous, cardiac, respiratory, gastrointestinal, renal, and hematological systems. Preoperative identification, optimization, and tailored anesthetic management are essential for optimum outcomes in patients with liver disease undergoing surgery. The coagulopathy of liver failure is a balanced coagulopathy better assessed by thromboelastography than conventional testing, and it is not directly associated with bleeding risk.

Coagulation testing and management in liver disease patients

PURPOSE OF REVIEW

The present article aims to provide clinicians with an overview of coagulation testing in individuals with liver disease, to discuss available procoagulants and the rationale for their use, and to provide management strategies in a variety of common clinical scenarios.

RECENT FINDINGS

Clinicians and researchers are gaining an increased understanding of the shortfalls of assessing bleeding risk using traditional tests of coagulation. The use of global tests of clot formation, including viscoelastic testing and thrombin generation analysis, continues to evolve and guide the management of these patients.

SUMMARY

Abnormal coagulation testing in individuals with cirrhosis leads to a variety of difficult clinical scenarios that can be challenging for practitioners. With advanced liver disease, changes in the traditional tests of hemostasis such as the international normalized ratio reflect decreased synthesis of procoagulant factors but do not capture concomitant decreases in anticoagulant factors. In this setting, transfusion thresholds targeting platelet and fibrinogen goals may provide an effective strategy to optimize clot formation. Global tests of clot formation provide practical information to clinicians and can help guide decision making, although optimal target levels have not been validated.

Anesthesia for the Patient with Severe Liver Failure

The incidence of liver failure continues to increase, and it is associated with increased perioperative morbidity and mortality. Liver failure is associated with multiorgan dysfunction, including central nervous, cardiac, respiratory, gastrointestinal, renal, and hematological systems. Preoperative identification, optimization, and tailored anesthetic management are essential for optimum outcomes in patients with liver disease undergoing surgery. The coagulopathy of liver failure is a balanced coagulopathy better assessed by thromboelastography than conventional testing, and it is not directly associated with bleeding risk.

Intraoperative Plasma Transfusion Volumes and Outcomes in Cardiac Surgery

OBJECTIVE

Assess outcomes after intraoperative plasma transfusion in patients undergoing cardiac surgery.

DESIGN

Retrospective study of adult cardiac surgical between 2011 and 2015. Relationships between plasma transfusion volume, coagulation test values, and a primary outcome of early postoperative red blood cell (RBC) transfusion were assessed via multivariable regression analyses. Secondary outcomes included hospital mortality, intensive care unit and hospital-free days, intraoperative RBCs, estimated blood loss, and reoperation for bleeding.

SETTING

Academic tertiary referral center.

PARTICIPANTS

A total of 1,794 patients received intraoperative plasma transfusions during the study period.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Higher plasma transfusion volumes were associated with worse clinical outcomes, with each 1-unit increase being associated with greater odds for postoperative RBCs [odds ratio (OR) 1.12 (confidence interval [CI] 1.04-1.20); p = 0.002], intraoperative [OR 1.85 (CI 1.69-2.03); p < 0.001], and fewer hospital-free days [mean -0.20 (-0.39, -0.01); p = 0.04]. Each 0.1 increase in pretransfusion International Normalized Ratio (INR) was associated with increased odds of postoperative and intraoperative RBCs, reoperation for bleeding, and fewer intensive care unit and hospital-free days. For given plasma volumes, patients achieving greater reduction in elevated pretransfusion INR values experienced more favorable outcomes.

CONCLUSIONS

In patients undergoing cardiac surgery who received intraoperative plasma transfusion, higher plasma transfusion volumes were associated with inferior clinical outcomes. Higher pretransfusion INR values also were associated with worse outcomes; however, those achieving a greater degree of INR correction after plasma transfusion demonstrated more favorable outcomes. Prospective studies related to plasma transfusion are needed to address this important topic.

Higher intraoperative plasma transfusion volumes are associated with inferior perioperative outcomes

BACKGROUND

Intraoperative plasma transfusion is common, yet little is known regarding its effects on perioperative coagulation tests or clinical outcomes.

STUDY DESIGN AND METHODS

This is a retrospective cohort study of adults receiving intraoperative plasma transfusion at a single center from 2011 to 2015. Relationships between plasma transfusion volume, changes in coagulation test values, and clinical outcomes, including a primary outcome of early postoperative red blood cell (RBC) transfusion, were assessed with multivariable regression analyses. Secondary outcomes included hospital mortality, intensive care unit (ICU)- and hospital-free days, intraoperative RBC transfusions, and estimated blood loss.

RESULTS

A total of 3393 unique patients were included, with median (IQR) transfusion of 2 (2-4) units. In multivariable analyses, higher plasma volumes were associated with worse outcomes, with each 1 mL/kg increase associated with increased odds for postoperative (1.02 [1.01-1.03], p < 0.001) and intraoperative RBCs (1.17 [1.16-1.19], p < 0.001) and fewer ICU- and hospital-free days (mean difference [95% CI], -0.08 [-0.12 to -0.05], p < 0.001; and -0.09 [-0.13 to -0.06], p < 0.001, respectively). Greater decreases in international normalized ratio (INR) following plasma transfusion were associated with decreased odds of postoperative RBCs (0.35 [0.25-0.47], p < 0.001), decreased mortality (0.50 [0.31-0.83], p = 0.007), and increased mean ICU- (1.31 [0.41-2.21], p = 0.004) and hospital-free days (1.15 [0.19-2.10], p = 0.018).

CONCLUSION

In patients receiving intraoperative plasma transfusion, higher transfusion volumes were associated with inferior clinical outcomes; however, greater improvements in INR were associated with improved outcomes. Future prospective studies are necessary to better define these relationships and to explore plasma transfusion triggers beyond the limitations of INR.

Postoperative complications in cirrhotic pediatric deceased donor liver transplantation: Focus on transfusion therapy

Intraoperative transfusions seem associated with patient death and graft failure after PLTx. A retrospective analysis of recipients' and donors' characteristics and transplantation data in a cohort of patients undergoing PLTx from 2002 to 2009 at the Bergamo General Hospital was performed. A two-stage hierarchical Cox proportional hazard regression with forward stepwise selection was used to identify the main risk factors for major complications. In addition, propensity score analysis was used to adjust risk estimates for possible selection biases in the use of blood products. Over the 12-year period, 232 pediatric cirrhotic patients underwent PLTx. One-year patient and graft survival rates were 92.3% and 83.7%, respectively. The Kaplan-Meier shows that the main decrease in both graft and patient survival occurs during the first months post-transplantation. At the same time, it appears that most of the complications occur during the first month post-transplantation. One-month and 1-year patient complication-free survival rates were 24.8% and 12.1%, respectively. Our study shows that intraoperative red blood cells and platelet transfusions are independent risk factors for developing one or more major complications in the first year after PLTx. Decreasing major complications will improve the health status and overall long-term patient survival after pediatric PLTx.

Anesthetic Management for Prolonged Incidental Surgery in Advanced Liver Disease

In spite of advances in perioperative management, operative procedures in patients with chronic liver disease pose a significant challenge for the anesthesiologist due to multisystem involvement, high risk of postoperative hepatic decompensation, and mortality. We describe the anesthetic management of an elderly patient with advanced liver disease (model for end-stage liver disease 16) for prolonged abdominal surgery. The use of invasive hemodynamic monitoring, point-of-care biochemical, and hematological surveillance coupled with prompt correction of all abnormalities was responsible for good outcome. The patient's inguinal swellings turned out to be extensions of a large peritoneal mesothelioma, necessitating a large abdominal incision and blood loss. Analgesia was provided by bilateral transversus abdominis plane blocks, which helped to reduce opioid use and rapid extubation.

Effects of preanalytical frozen storage time and temperature on screening coagulation tests and factors VIII and IX activity

Preanalytical quality control of blood samples is critical for tests of coagulation function and coagulation factor activity. Preanalytical storage time and temperature are the main variables. We investigated the effects of preanalytical frozen storage time and temperature on activated partial thromboplastin time (APTT), fibrinogen (Fbg), prothrombin time (PT)/international normalized ratio (INR), thrombin time (TT), factor VIII activity (FVIII:C), and factor IX activity (FIX:C) in frozen plasma. Samples (n = 144) were randomly and equally divided into four groups (storage at −80 °C or −20 °C) and analysed by CS5100 or CA7000 coagulation analysers. Baseline values and results after storage for 15 days, 1 month, 3 months, 6 months, and 1 year were measured after thawing. Mean percent changes and scatter plots were used to determine clinically relevant differences. The stabilities of coagulation tests and coagulation factor activities measured by the CS5100 system were consistent with those measured by the CA7000 system. At −80 °C, assessment samples of PT/INR, Fbg, and TT can be safely stored for 1 year, APTT for 6 months, and FVIII:C and FIX:C for 1 month. At −20 °C, samples of Fbg and TT can be stored for 1 year, PT/INR and FIX:C for 1 month, and APTT and FVIII:C for 15 days.

Investigation of the status quo of massive blood transfusion in China and a synopsis of the proposed guidelines for massive blood transfusion

The aim of this study was to provide an overview of massive transfusion in Chinese hospitals, identify the important indications for massive transfusion and corrective therapies based on clinical evidence and supporting experimental studies, and propose guidelines for the management of massive transfusion. This multiregion, multicenter retrospective study involved a Massive Blood Transfusion Coordination Group composed of 50 clinical experts specializing in blood transfusion, cardiac surgery, anesthesiology, obstetrics, general surgery, and medical statistics from 20 tertiary general hospitals across 5 regions in China. Data were collected for all patients who received ≥10 U red blood cell transfusion within 24 hours in the participating hospitals from January 1 2009 to December 31 2010, including patient demographics, pre-, peri-, and post-operative clinical characteristics, laboratory test results before, during, and after transfusion, and patient mortality at post-transfusion and discharge. We also designed an in vitro hemodilution model to investigate the changes of blood coagulation indices during massive transfusion and the correction of coagulopathy through supplement blood components under different hemodilutions. The experimental data in combination with the clinical evidence were used to determine the optimal proportion and timing for blood component supplementation during massive transfusion. Based on the findings from the present study, together with an extensive review of domestic and international transfusion-related literature and consensus feedback from the 50 experts, we drafted the guidelines on massive blood transfusion that will help Chinese hospitals to develop standardized protocols for massive blood transfusion.

Coagulopathy of Trauma

Coagulopathy is common after injury and develops independently from iatrogenic, hypothermic, and dilutional causes. Despite considerable research on the topic over the past decade, trauma-induced coagulopathy (TIC) continues to portend poor outcomes, including decreased survival. We review the current evidence regarding the diagnosis and mechanisms underlying trauma induced coagulopathy and summarize the debates regarding optimal management strategy including product resuscitation, potential pharmacologic adjuncts, and targeted approaches to hemostasis. Throughout, we will identify areas of continued investigation and controversy in the understanding and management of TIC.

Prophylactic plasma transfusion for surgical patients with abnormal preoperative coagulation tests: a single-institution propensity-adjusted cohort study

BACKGROUND

Perioperative haemorrhage negatively affects patient outcomes and results in substantial consumption of health-care resources. Plasma transfusions are often administered to address abnormal preoperative coagulation tests, with the hope to mitigate bleeding complications. We aimed to assess the associations between preoperative plasma transfusion and bleeding complications in patients with elevated international normalised ratio (INR) undergoing non-cardiac surgery.

METHODS

We did an observational study in a consecutive sample of adult patients undergoing non-cardiac surgery with preoperative INR greater than or equal to 1·5. The exposure of interest was transfusion of preoperative plasma for elevated INR. The primary outcome was WHO grade 3 bleeding in the early perioperative period (from entry into the operating room until 24 h following exit from operating room). Hypotheses were tested with univariate and propensity-matched analyses. We did multiple sensitivity analyses to further evaluate the robustness of study findings.

FINDINGS

Between Jan 1, 2008, and Dec 31, 2011, we identified 1234 (8·4%) of 14 743 patients who had an INR of 1·5 or above and were included in this investigation. Of 1234 study participants, 139 (11%) received a preoperative plasma transfusion. WHO grade 3 bleeding occurred in 73 (53%) of 139 patients who received preoperative plasma compared with 350 (32%) of 1095 patients who did not (odds ratio [OR] 2·35, 95% CI 1·65-3·36; p<0·0001). Among the propensity-matched cohort, 65 (52%) of 125 plasma recipients had WHO grade 3 bleeding compared with 97 (40%) of 242 of those who did not receive preoperative plasma (OR 1·75, 95% CI 1·09-2·81; p=0·021). Results from multiple sensitivity analyses were qualitatively similar.

INTERPRETATION

Preoperative plasma transfusion for elevated international normalised ratios was associated with an increased frequency of perioperative bleeding complications. Findings were robust in the sensitivity analyses, suggestive that more conservative management of abnormal preoperative international normalised ratios is warranted.

FUNDING

Mayo Clinic, National Institutes of Health.

Coagulopathy and transfusion therapy in pediatric liver transplantation

Bleeding and coagulopathy are critical issues complicating pediatric liver transplantation and contributing to morbidity and mortality in the cirrhotic child. The complexity of coagulopathy in the pediatric patient is illustrated by the interaction between three basic models. The first model, "developmental hemostasis", demonstrates how a different balance between pro- and anticoagulation factors leads to a normal hemostatic capacity in the pediatric patient at various ages. The second, the "cell based model of coagulation", takes into account the interaction between plasma proteins and cells. In the last, the concept of "rebalanced coagulation" highlights how the reduction of both pro- and anticoagulation factors leads to a normal, although unstable, coagulation profile. This new concept has led to the development of novel techniques used to analyze the coagulation capacity of whole blood for all patients. For example, viscoelastic methodologies are increasingly used on adult patients to test hemostatic capacity and to guide transfusion protocols. However, results are often confounding or have limited impact on morbidity and mortality. Moreover, data from pediatric patients remain inadequate. In addition, several interventions have been proposed to limit blood loss during transplantation, including the use of antifibrinolytic drugs and surgical techniques, such as the piggyback and lowering the central venous pressure during the hepatic dissection phase. The rationale for the use of these interventions is quite solid and has led to their incorporation into clinical practice; yet few of them have been rigorously tested in adults, let alone in children. Finally, the postoperative period in pediatric cohorts of patients has been characterized by an enhanced risk of hepatic vessel thrombosis. Thrombosis in fact remains the primary cause of early graft failure and re-transplantation within the first 30 d following surgery, and it occurs despite prolongation of standard coagulation assays. Data, however, are currently lacking regarding the use of anti-aggregation/anticoagulation therapies and how to best monitor for thrombosis in the early postoperative period in pediatric patients. Therefore, further studies are necessary to elucidate the interaction between the development of the coagulation system and cirrhosis in children. Moreover, strategies to optimize blood transfusion and anticoagulation must be tested specifically in pediatric patients. In conclusion, data from the adult world can be translated with difficulty into the pediatric field as indication for transplantation, baseline pathologies and levels of pro- and anticoagulation factors are not comparable between the two populations.

Indications and Effects of Plasma Transfusions in Critically Ill Children

RATIONALE

Plasma transfusions are frequently prescribed for critically ill children, although their indications lack a strong evidence base. Plasma transfusions are largely driven by physician conceptions of need, and these are poorly documented in pediatric intensive care patients.

OBJECTIVES

To identify patient characteristics and to characterize indications leading to plasma transfusions in critically ill children, and to assess the effect of plasma transfusions on coagulation tests.

METHODS

Point-prevalence study in 101 pediatric intensive care units in 21 countries, on 6 predefined weeks. All critically ill children admitted to a participating unit were included if they received at least one plasma transfusion.

MEASUREMENTS AND MAIN RESULTS

During the 6 study weeks, 13,192 children were eligible. Among these, 443 (3.4%) received at least one plasma transfusion and were included. The primary indications for plasma transfusion were critical bleeding in 22.3%, minor bleeding in 21.2%, planned surgery or procedure in 11.7%, and high risk of postoperative bleeding in 10.6%. No bleeding or planned procedures were reported in 34.1%. Before plasma transfusion, the median international normalized ratio (INR) and activated partial thromboplastin time (aPTT) values were 1.5 and 48, respectively. After plasma transfusion, the median INR and aPTT changes were -0.2 and -5, respectively. Plasma transfusion significantly improved INR only in patients with a baseline INR greater than 2.5.

CONCLUSIONS

One-third of transfused patients were not bleeding and had no planned procedure. In addition, in most patients, coagulation tests are not sensitive to increases in coagulation factors resulting from plasma transfusion. Studies assessing appropriate plasma transfusion strategies are urgently needed.

Prothrombin complex concentrate for reversal of vitamin K antagonist treatment in bleeding and non-bleeding patients

BACKGROUND

Treatment with vitamin K antagonists is associated with increased morbidity and mortality. Reversal therapy with prothrombin complex concentrate (PCC) is used increasingly and is recommended in the treatment of patients with bleeding complications undertaking surgical interventions, as well as patients at high risk of bleeding. Evidence is lacking regarding indication, dosing, efficacy and safety.

OBJECTIVES

We assessed the benefits and harms of PCC compared with fresh frozen plasma in the acute medical and surgical setting involving vitamin K antagonist-treated bleeding and non-bleeding patients. We investigated various outcomes and predefined subgroups and performed sensitivity analysis. We examined risks of bias and applied trial sequential analyses (TSA) to examine the level of evidence, and we prepared a 'Risk of bias' table to test the quality of the evidence.

SEARCH METHODS

We searched the following databases from inception to 1 May 2013: Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE (Ovid SP); EMBASE (Ovid SP); International Web of Science; Latin American and Caribbean Health Sciences Literature (LILACS) (via BIREME); the Chinese Biomedical Literature Database; advanced Google and the Cumulative Index to Nursing and Allied Health Literature (CINAHL). We applied a systematic and sensitive search strategy to identify relevant randomized clinical trials and imposed no language or date restrictions. We adapted our MEDLINE search strategy for searches in all other databases. We reran the search in October 2014 and found one potential new study of interest. We added this study to a list of 'Studies awaiting classification', and we will incorporate this study into the formal review findings at the time of the review update.

SELECTION CRITERIA

We included randomized controlled trials (RCTs), irrespective of publication status, date of publication, blinding status, outcomes published or language. We contacted investigators and study authors to request relevant data.

DATA COLLECTION AND ANALYSIS

Three review authors independently abstracted data and resolved disagreements by discussion. Our primary outcome measures were 'overall mortality longest follow-up' and 'overall 28-day mortality'. We performed subgroup analyses to assess the effects of PCC in adults in terms of various clinical and physiological outcomes. We presented pooled estimates of the effects of interventions on dichotomous outcomes as risk ratios (RRs), and on continuous outcomes as mean differences (MDs), with 95% confidence intervals (CIs). We assessed risk of bias by assessing trial methodological components and risk of random error through TSA.

MAIN RESULTS

We included four RCTs with a total of 453 participants and determined that none of these trials had overall low risk of bias. We found six ongoing trials from which we were unable to retrieve further data. Three trials provided data on mortality. Meta-analysis showed no statistical effect on overall mortality (RR 0.93, 95% CI 0.37 to 2.33; very low quality of evidence). We were unable to associate use of PCC with the number of complications probably related to the intervention (RR 0.92, 95% CI 0.78 to 1.09; very low quality of evidence). Lack of transfusion data and apparent differences in study design prevented review authors from finding a beneficial effect of PCC in reducing the volume of fresh frozen plasma (FFP) transfused to reverse the effect of vitamin K antagonist treatment. The number of new occurrences of transfusion of red blood cells (RBCs) did not seem to be associated with the use of PCC (RR 1.08, 95% CI 0.82 to 1.43; very low quality of evidence). Still, the included studies demonstrate the possibility of equally reversing vitamin K-induced coagulopathy using PCC without the need for transfusion of FFP. No effect on other predefined outcomes was observed.

AUTHORS' CONCLUSIONS

In the four included RCTs, use of prothrombin complex concentrate does not appear to reduce mortality or transfusion requirements but demonstrates the possibility of reversing vitamin K-induced coagulopathy without the need for transfusion of fresh frozen plasma. All included trials have high risk of bias and are underpowered to detect mortality, benefit or harm. Clinical and statistical heterogeneity is high, and definitions of clinically important outcomes such as adverse events are highly dissimilar between trials. Only weak observational evidence currently supports the use of PCC in vitamin K antagonist-treated bleeding and non-bleeding patients, and the current systematic review of RCTs does not support the routine use of PCC over FFP. Additional high-quality research is urgently needed.

Coagulation defects associated with massive blood transfusion: A large multicenter study

The variations in the coagulation indices of patients receiving massive blood transfusion were investigated across 20 large-scale general hospitals in China. The data of 1,601 surgical inpatients receiving massive transfusion were retrospectively collected and the trends in the platelet counts and coagulation indices prior to and at 16 different time points during packed red blood cell (pRBC; after 2–40 units of pRBC) transfusion were evaluated by linear regression analysis. Temporal variations in the means of prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT) and fibrinogen (FIB) concentration were also assessed and the theoretical estimates and actual measurements of the platelet count were compared. The results demonstrated that the platelet count decreased linearly with an increase in the number of pRBC units transfused (Y=150.460−3.041X; R² linear=0.775). Following transfusion of 18 units of pRBC (0.3 units of pRBC transfused per kilogram of body weight), the average platelet count decreased to 71×10⁹/l (<75×10⁹/l). Furthermore, variations in the means of PT, INR, APTT and FIB did not demonstrate any pronounced trends and actual platelet counts were markedly higher than the theoretical estimates. In conclusion, no variations in the means of traditional coagulation indices were identified, however, the platelet count demonstrated a significant linear decrease with an increase in the number of pRBC units transfused. Furthermore, actual platelet counts were higher than theoretical estimates, indicating the requirement for close monitoring of actual platelet counts during massive pRBC transfusion.

Balanced ratio of plasma to packed red blood cells improves outcomes in massive transfusion: A large multicenter study

Resuscitation with the early administration of plasma can improve the survival of patients undergoing surgery or trauma patients who require massive transfusion. To ascertain the optimal ratio of fresh frozen plasma (FFP) to packed red blood cells (pRBCs) in massive transfusions, the records of 1,048 patients who received a massive transfusion at 20 hospitals were retrospectively reviewed. The patients were stratified into three groups according to the ratio of FFP to pRBCs. These were the low (<1:2.3), middle (1:2.3-0.75) and high (≥1:0.75) ratio groups. For 24-h treatment, the middle FFP:pRBC ratio led to a lower mortality rate (9.31%) compared with that in the low (11.83%) and high (11.44%) ratio groups (P=0.477). For 72-h treatment, the middle FFP:pRBC ratio also lead to the lowest mortality rate (7.25%), which was significantly lower than the ratios in the low (10.39%) and high (13.65%) ratio groups (P=0.007). The length of hospital stay, ICU stay, and FFP:pRBC ratio in 72 h were found to be significant associated with mortality. The optimal ratio of FFP to pRBCs of 1:2.3-0.75 in 72 h can improve the survival of patients undergoing massive transfusions.

Role of prothrombin complex concentrate in perioperative coagulation therapy

Prothrombin complex concentrate (PCC) is a term to describe pharmacological products that contain lyophilized, human plasma-derived vitamin K-dependent factors (F), FII, FVII, FIX, FX, and various amounts of proteins C and S. PCCs can be rapidly reconstituted in a small volume (20 ml for about 500 international units (IU)) at bedside and administered regardless of the patient's blood type. PCCs are categorized as 4-factor PCC if they contain therapeutic amounts of FVII, and 3-factor PCC when FVII content is low. In addition, activated PCC which contains activated FVII and FX with prothrombin is available for factor VIII bypassing therapy in hemophilia patients with inhibitors. Currently, 4-factor PCC is approved for the management of bleeding in patients taking warfarin, but there has been increasing use of various PCCs in the treatment of acquired perioperative coagulopathy unrelated to warfarin therapy and in the management of bleeding due to novel oral anticoagulants. There is also an ongoing controversy about plasma transfusion and its potential hazards including transfusion-related lung injury (TRALI). Early fixed ratio plasma transfusion has been implemented in many trauma centers in the USA, whereas fibrinogen concentrate and PCC are preferred over plasma transfusion in some European centers. In this review, the rationales for including PCCs in the perioperative hemostatic management will be discussed in conjunction with plasma transfusion.

Correction of blood coagulation dysfunction and anemia by supplementation of red blood cell suspension, fresh frozen plasma, and apheresis platelet: results of in vitro hemodilution experiments

PURPOSE

This study aimed to determine the optimal composition and timing for the administration of blood supplements during in vivo blood transfusion with red blood cells suspension (pRBC), fresh frozen plasma (FFP), and apheresis platelet (PLT) administered for the correction of anemia and coagulation dysfunction caused by in vitro hemodilution.

MATERIALS AND METHODS

We collected blood samples from 24 healthy volunteers and prepared various dilutions of whole blood with normal saline: 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, and 1:9. The diluted blood samples were then supplemented with blood components at various proportions and then analyzed to determine the values of the routine blood indices, coagulation indices, and thromboelastogram measures.

RESULTS

At hemodilutions of 40%, 50%, and 60%, the hemoglobin, coagulation indices, and platelet number and function reached critical levels, necessitating supplementation with pRBC, FFP, and PLT, respectively. When hemodilution was 90%, the supplementation required was approximately 1:1.3:0.9 of pRBC/FFP/PLT.

CONCLUSION

The use of pRBC, FFP, and PLT in appropriate proportions can correct the blood coagulation dysfunction and anemia caused by in vitro hemodilution, and these proportions can be used as guidelines for in vivo massive transfusion.

Novel approaches in management of perioperative coagulopathy

PURPOSE OF REVIEW

The recent advances in hemostatic monitoring, and discussion of the clinical implications of hemostatic therapies based on different blood components and factor concentrates.

RECENT FINDINGS

Implementing suitable laboratory tests and transfusion protocols is highly recommended because the laboratory test guided, protocol-driven transfusion approach reduces blood component utilization, and possibly leads to improved outcomes. Timely assessment of coagulation has been difficult using conventional coagulation tests, but thrombocytopenia, fibrin polymerization defects, and fibrinolysis can be quickly assessed on thromboelastometry. The latter testing can be applied to guide the dosing of fibrinogen and prothrombin complex concentrate, which are selectively used to correct fibrinogen deficiency, and improve thrombin generation in acquired coagulopathy. These therapeutic approaches are novel, and potentially effective in reducing the exposure to allogeneic components (e.g., plasma and platelets) and side-effects of transfusion. Although the accessibility of different therapies among different countries, tranexamic acid is widely available, and is an effective blood conservation measure with a good safety profile in various surgical settings.

SUMMARY

Our understanding of perioperative coagulopathy, diagnostic tools, and therapeutic approaches has evolved in recent years. Additional multidisciplinary efforts are required to understand the optimal combinations, cost-effectiveness, and safety profiles of allogeneic components, and available factor concentrates.

The impact of perioperative transfusion of blood products on survival after pediatric liver transplantation

Intraoperative transfusion of red blood cells (RBC) is associated with adverse outcome after LT in adult patients. This relationship in pediatric patients has not been studied in depth, and its analysis is the scope of this study. Forty-one variables associated with outcome, including blood product transfusions, were studied in a cohort of 243 pediatric patients undergoing a cadaveric LT between 2002 and 2009 at the General Hospital of Bergamo. Multivariate stepwise Cox proportional hazards models were adopted with adjustment by propensity scores to minimize factors associated with the use of blood products. Median age at transplant was 1.37 yr. In uni- and multivariate analyses, perioperative transfusion of FFP and RBC was an independent risk factor for predicting one-yr patient and graft survival. The effect on one-yr survival was dose-related with a hazard ratio of 3.15 for three or more units of RBC (p = 0.033) and 3.35 for three or more units of FFP (p = 0.021) when compared with 1 or no units transfused. The negative impact of RBC and FFP transfusion was confirmed by propensity score-adjusted analysis. These findings may have important implications for transfusion practice in the LT pediatric recipients.

Clinical use of fresh-frozen plasma in neonatal intensive care unit

Recommendations for FFP use in neonates are based on a very limited amount of data, and not on well-designed randomized controlled trials. This retrospective study was performed to analyze our experience with FFP use in neonatal intensive care unit (NICU). From January 2006 until August 2011 a total of 80 neonates were identified as having been treated with FFP. The most common indication for FFP use was prolonged PT or aPTT, representing 32.8% of all usages of FFP. Following FFT treatment PT and aPTT normalized in 42% and 60% patients, respectively. Our results suggest that FFP were often used in acceptable indications in NICU.

Coagulation in hepatobiliary disease

OBJECTIVE

To review the pathogenesis and clinical consequences of coagulation abnormalities accompanying hepatobiliary disorders and to highlight the need for further studies to characterize these derangements and their treatment options in small animal patients.

DATA SOURCES

Veterinary and human medical literature: original research articles, scientific reviews, consensus statements, and recent texts.

SUMMARY

The liver plays an important role in the production and clearance of many components of coagulation. A wide range of hemostatic derangements can occur in patients with hepatobiliary disease including alterations in platelet number and function, coagulation factor levels, anticoagulants, vascular endothelial function, and fibrinolysis. As these hemostatic alterations include both pro- and anticoagulation pathways, the net result is often a rebalanced hemostatic system that can be easily disrupted by concurrent conditions resulting in either clinical bleeding or thrombosis. Conventional coagulation tests are inadequate at identifying the spectrum of coagulation alterations occurring in patients with hepatobiliary disease, but their evaluation is necessary to assess bleeding risk and provide prognostic information. A paucity of information exists regarding the treatment of the coagulation derangements in small animals with hepatobiliary disease. Extrapolation from human studies provides some information about potential treatment options, but further studies are warranted in this area to elucidate the best management for coagulation abnormalities in dogs and cats with hepatobiliary disease.

CONCLUSION

Hepatobiliary disease can have profound effects on coagulation function leading to hypercoagulable or hypocoagulable states. Overall coagulation status with hepatobiliary disease depends on both the type and severity of disease and the presence of associated complications.

[Principles of perioperative coagulation management]

The coagulation system is a complex network of interacting proteins and cells with extensive sensitivity, amplification and control pathways. The system represents a delicate balance between procoagulant and anticoagulant as well as profibrinolytic and antifibrinolytic activities. Clinically relevant phenotypes, e.g. bleeding and thrombosis, occur immediately when this balance is no longer in equilibrium. A correct understanding of the complex coagulation pathophysiology in the perioperative setting is essential for an effective treatment. In a bleeding patient, patient's history, clinical findings, routine and advanced laboratory coagulation testing as well as point-of-care coagulation monitoring help to reliably and readily identify the underlying coagulation disorder. Modern coagulation management is proactive, individualized, balanced and follows clearly defined algorithms. Coagulopathic bleeding can be successfully controlled with specific interventions in the coagulation system.

Comparison of point-of-care testing (POCT): i-STAT(®) international normalized ratio (INR) vs reference laboratory INR in pediatric patients undergoing major surgery

BACKGROUND

The aim of the study was to compare international normalized ratio (INR) results obtained by point-of-care testing (i-STAT® device) with the reference laboratory INR in children undergoing major surgery with expected significant blood loss.

METHODS

  Pediatric patients undergoing craniofacial, spine, hip, or cancer surgery were included. Blood samples for coagulation testing were tested at several intraoperative time points and generally withdrawn from the arterial catheter, if accessible. A volume of 1.4 ml citrated blood was used for the reference laboratory INR test, and 0.1 ml of blood was taken for the whole blood INR test using the i-STAT® device. Blood samples for both tests were withdrawn at the same time and immediately analyzed with both devices.

RESULTS

A total of 169 paired blood samples were taken intraoperatively from 44 pediatric patients [IQR 0.9-10.7 years (median 3.3)]. Reference laboratory INR ranged from 0.96 to 3.43 (mean 1.40; sd 0.32) and INR of i-STAT® from 0.95 to 2.29 (mean 1.26; sd 0.22). The correlation coefficient was 0.83 (P < 0.001), and the bias values were 0.12 and 0.55 at the medical decision level of ≤2.0 and >2.0, respectively.

CONCLUSIONS

In the perioperative setting, point-of-care INR testing in children using the i-STAT® device is a reliable and easy-to-handle method for INR values ≤2.0, while INR values >2.0 might be underestimated.

[Principles of perioperative coagulation management]

The coagulation system is a complex network of interacting proteins and cells with extensive sensitivity, amplification and control pathways. The system represents a delicate balance between procoagulant and anticoagulant as well as profibrinolytic and antifibrinolytic activities. Clinically relevant phenotypes, e.g. bleeding and thrombosis, occur immediately when this balance is no longer in equilibrium. A correct understanding of the complex coagulation pathophysiology in the perioperative setting is essential for an effective treatment. In a bleeding patient, patient's history, clinical findings, routine and advanced laboratory coagulation testing as well as point-of-care coagulation monitoring help to reliably and readily identify the underlying coagulation disorder. Modern coagulation management is proactive, individualized, balanced and follows clearly defined algorithms. Coagulopathic bleeding can be successfully controlled with specific interventions in the coagulation system.

Evaluation and management of shock States: hypovolemic, distributive, and cardiogenic shock

Shock states have multiple etiologies, but all result in hypoperfusion to vital organs, which can lead to organ failure and death if not quickly and appropriately managed. Pharmacists should be familiar with cardiogenic, distributive, and hypovolemic shock and should be involved in providing safe and effective medical therapies. An accurate diagnosis is necessary to initiate appropriate lifesaving interventions and target therapeutic goals specific to the type of shock. Clinical signs and symptoms, as well as hemodynamic data, help with initial assessment and continued monitoring to provide adequate support for the patient. It is necessary to understand these hemodynamic parameters, medication mechanisms of action, and available mechanical support when developing a patient-specific treatment plan. Rapid therapeutic intervention has been proven to decrease morbidity and mortality and is crucial to providing the best patient outcomes. Pharmacists can provide their expertise in medication selection, titration, monitoring, and dose adjustment in these critically ill patients. This review will focus on parameters used to assess hemodynamic status, the major causes of shock, pathophysiologic factors that cause shock, and therapeutic interventions that should be employed to improve patient outcomes.