-
1.
Effects of serum fibrinogen correction on outcome of traumatic cranial surgery: A randomized, single-blind, placebo-controlled clinical trial
Niakan A, Khalili H, Vosoughi M, Azizi E, Ghaffarpasand F
Clinical neurology and neurosurgery. 2023;229:107709
Abstract
BACKGROUND Traumatic brain injury (TBI) is strongly associated with coagulopathy that occurs in 25-35% of patients. This complication is linked to higher mortality and morbidity. Recent lines of evidance have supported administration of fibrinogen concentrate (FC) in patients with severe TBI, while its efficacy remains controversial. In this study we aim to evaluate the effectiveness of serum fibrinogen level correction from 1.5 and 2.0 g/l to more than 2.0 g/l in patients with severe TBI undergoing traumatic cranial surgery. METHOD This randomized, single-blind, placebo-controlled clinical trial included trauma patients who had abbreviated injury scale (AIS) more than 3 in head and below 3 in other organs. FC was administered intravenously to patients with severe TBI undergoing TBI to correct the fibrinogen level above 2 g/l. Patients were randomly assigned to FC and control groups. The amount of intra-operative blood loss, packed cell (PC) transfusion, formation of new intracranial hemorrhage, and hemovac drainage were compared between the two study groups. RESULTS Forty-seven of 65 participants received the study intervention within 40-112 min of admission. Intra-operative PC transfusion was higher in FC group (80%) compared to control group (55.5%) while the differance was not statistically significant (p > 0.05). Intra-operative blood loss was significantly higher in control group than FC group (P = 0.036). Chance of re-operation and new intracranial hematoma were not significantly different between two study groups. CONCLUSION Early delivery of FC, decreases intraoperative bleeding. Although based on our findings it has no other effect on other parameters, further multicenter studies are recommended to investigate the role of early FC administration in management of post traumatic coagulopathy.
-
2.
Emergency administration of fibrinogen concentrate for haemorrhage: systematic review and meta-analysis
Itagaki Y, Hayakawa M, Takahashi Y, Hirano S, Yamakawa K
World journal of emergency surgery : WJES. 2023;18(1):27
-
-
-
Free full text
-
Editor's Choice
Abstract
INTRODUCTION The occurrence of massive haemorrhages in various emergency situations increases the need for blood transfusions and increases the risk of mortality. Fibrinogen concentrate (FC) use may increase plasma fibrinogen levels more rapidly than fresh-frozen product or cryoprecipitate use. Previous several systematic reviews and meta-analyses have not effectively demonstrated FC efficacy in significantly improving the risk of mortality and reducing transfusion requirements. In this study, we investigated the use of FC for haemorrhages in emergency situations. METHODS AND ANALYSIS In this systematic review and meta-analysis, we included controlled trials, but excluded randomized controlled trials (RCTs) in elective surgeries. The study population consisted of patients with haemorrhages in emergency situations, and the intervention was emergency supplementation of FC. The control group was administered with ordinal transfusion or placebo. The primary and secondary outcomes were in-hospital mortality and the amount of transfusion and thrombotic events, respectively. The electronic databases searched included MEDLINE (PubMed), Web of Science, and the Cochrane Central Register of Controlled Trials. RESULTS Nine RCTs in the qualitative synthesis with a total of 701 patients were included. Results showed a slight increase in in-hospital mortality with FC treatment (RR 1.24, 95% CI 0.64-2.39, p = 0.52) with very low certainty of the evidence. There was no reduction in the use of red blood cells (RBC) transfusion in the first 24 h after admission with FC treatment (mean difference [MD] 0.0 Unit in the FC group, 95% CI - 0.99-0.98, p = 0.99) with very low certainty of the evidence. However, the use of fresh-frozen plasma (FFP) transfusion significantly increased in the first 24 h after admission with FC treatment (MD 2.61 Unit higher in the FC group, 95% CI 0.07-5.16, p = 0.04). The occurrence of thrombotic events did not significantly differ with FC treatment. CONCLUSIONS The present study indicates that the use of FC may result in a slight increase in in-hospital mortality. While FC did not appear to reduce the use of RBC transfusion, it likely increased the use of FFP transfusion and may result in a large increase in platelet concentrate transfusion. However, the results should be interpreted cautiously due to the unbalanced severity in the patient population, high heterogeneity, and risk of bias.
PICO Summary
Population
Patients admitted to hospital with emergency haemorrhage (9 randomised controlled trials, n= 701).
Intervention
Emergency supplementation of fibrinogen concentrate (FC).
Comparison
Standard transfusion treatments or placebo.
Outcome
Results showed a slight increase in in-hospital mortality with FC treatment (RR 1.24; 95% CI [0.64, 2.39]) with very low certainty of the evidence. There was no reduction in the use of red blood cells transfusion in the first 24 h after admission with FC treatment (mean difference [MD] 0.0 Unit in the FC group, 95% CI [- 0.99, 0.98]) with very low certainty of the evidence. The use of fresh-frozen plasma transfusion significantly increased in the first 24 h after admission with FC treatment (MD 2.61 Unit higher in the FC group, 95% CI [0.07, 5.16]). The occurrence of thrombotic events did not significantly differ with FC treatment.
-
3.
Blood component requirements in liver transplantation: effect of 2 thromboelastometry-guided strategies for bolus fibrinogen infusion-the TROMBOFIB randomized trial
Caballero, M., Sabate, A., Gutierrez, R., Beltran, J., Pérez, L., Pujol, R., Viguera, L., Costa, M., Reyes, R., Martinez, A., et al
Journal of Thrombosis and Haemostasis : Jth. 2023;21(1):37-46
Abstract
BACKGROUND A low plasma fibrinogen level influences blood component transfusion. Thromboelastometry provides clinical guidance for fibrinogen replacement in liver transplantation (LT). OBJECTIVES We hypothesized that infusions of fibrinogen concentrate to reach an A10(FibTem) value of 11 mm during LT could reduce red blood cell (RBC) and other component and fluid requirements in comparison to standard care. METHODS This randomized, blinded, multicenter trial in 3 hospitals enrolled 189 LT-scheduled patients allocated to an intervention target (A10(FibTem), 11 mm) or a standard target (A10(FibTem), 8 mm); 176 patients underwent LT with fibrinogen replacement. Data were analyzed by intention-to-treat (intervention group, 91; control group, 85). Blood was extracted, and fibrinogen kits were prepared to bring each patient's fibrinogen level to the assigned target at the start of LT, after portal vein clamping, and after graft reperfusion. The main outcome was the proportion of patients requiring RBC transfusion during LT or within 24 hours. RESULTS The proportion of patients requiring RBCs did not differ between the groups: intervention, 74.7% (95% CI, 65.5%-83.3%); control, 72.9% (95% CI, 62.2%-82.0%); absolute difference, 1.8% (95% CI, -11.1% to 14.78%) (P = .922). Thrombotic events occurred in 4% of the patients in both groups; reoperation and retransplantation rates and mortality did not differ. Nearly 70% of the patients in both groups required fibrinogen concentrate to reach the target. Using an 11-mm A10(FibTem) target increased the maximum clot firmness without affecting safety. However, this change provided no clinical benefits. CONCLUSION The similar low plasma fibrinogen concentrations could explain the lack of significant between-group outcomes.
-
4.
Cost-effectiveness of Fibrinogen Concentrate vs Cryoprecipitate for Treating Acquired Hypofibrinogenemia in Bleeding Adult Cardiac Surgical Patients
Abrahamyan L, Tomlinson G, Callum J, Carcone S, Grewal D, Bartoszko J, Krahn M, Karkouti K
JAMA surgery. 2023
-
-
-
Free full text
-
-
Editor's Choice
Abstract
IMPORTANCE Excessive bleeding requiring fibrinogen replacement is a serious complication of cardiac surgery. However, the relative cost-effectiveness of the 2 available therapies-fibrinogen concentrate and cryoprecipitate-is unknown. OBJECTIVE To determine cost-effectiveness of fibrinogen concentrate vs cryoprecipitate for managing active bleeding in adult patients who underwent cardiac surgery. DESIGN, SETTING, AND PARTICIPANTS A within-trial economic evaluation of the Fibrinogen Replenishment in Surgery (FIBERS) randomized clinical trial (February 2017 to November 2018) that took place at 4 hospitals based in Ontario, Canada, hospitals examined all in-hospital resource utilization costs and allogeneic blood product (ABP) transfusion costs incurred within 28 days of surgery. Participants included a subset of 495 adult patients from the FIBERS trial who underwent cardiac surgery and developed active bleeding and acquired hypofibrinogenemia requiring fibrinogen replacement. INTERVENTIONS Fibrinogen concentrate (4 g per dose) or cryoprecipitate (10 units per dose) randomized (1:1) up to 24 hours postcardiopulmonary bypass. MAIN OUTCOMES AND MEASURES Effectiveness outcomes included number of ABPs administered within 24 hours and 7 days of cardiopulmonary bypass. ABP transfusion (7-day) and in-hospital resource utilization (28-day) costs were evaluated and a multivariable net benefit regression model built for the full sample and predefined subgroups. RESULTS Patient level costs for 495 patients were evaluated (mean [SD] age 59.2 [15.4] years and 69.3% male.) Consistent with FIBERS, ABP transfusions and adverse events were similar in both treatment groups. Median (IQR) total 7-day ABP cost was CAD $2280 (US dollars [USD] $1697) (CAD $930 [USD $692]-CAD $4970 [USD $3701]) in the fibrinogen concentrate group and CAD $2770 (USD $1690) (IQR, CAD $1140 [USD $849]-CAD $5000 [USD $3723]) in the cryoprecipitate group. Median (interquartile range) total 28-day cost was CAD $38 180 (USD $28 431) $(IQR, CAD $26 350 [USD $19 622]-CAD $65 080 [USD $48 463]) in the fibrinogen concentrate group and CAD $38 790 (USD $28 886) (IQR, CAD $26 180 [USD $19 495]-CAD $70 380 [USD $52 409]) in the cryoprecipitate group. After exclusion of patients who were critically ill before surgery (11%) due to substantial variability in costs, the incremental net benefit of fibrinogen concentrate vs cryoprecipitate was positive (probability of being cost-effective 86% and 97% at $0 and CAD $2000 (USD $1489) willingness-to-pay, respectively). Net benefit was highly uncertain for nonelective and patients with critical illness. CONCLUSIONS AND RELEVANCE Fibrinogen concentrate is cost-effective when compared with cryoprecipitate in most bleeding adult patients who underwent cardiac surgery with acquired hypofibrinogenemia requiring fibrinogen replacement. The generalizability of these findings outside the Canadian health system needs to be verified.
PICO Summary
Population
A subset of patients enrolled in the FIBERS trial who underwent cardiac surgery and experienced bleeding resulting in acquired hyperfibrinogenemia (n= 495).
Intervention
Fibrinogen concentrate (n= 251).
Comparison
Cryoprecipitate (n= 244).
Outcome
Patient level costs were evaluated. Median (interquartile range (IQR)) total 7-day allogeneic blood product (ABP) cost was CAD $2,280 (US dollars [USD] $1,697) (CAD $930 [USD $692]-CAD $4,970 [USD $3,701]) in the fibrinogen concentrate group and CAD $2,770 (USD $1,690) (IQR, CAD $1,140 [USD $849]-CAD $5,000 [USD $3,723]) in the cryoprecipitate group. Median (IQR) total 28-day cost was CAD $38,180 (USD $28 431) (IQR, CAD $26,350 [USD $19,622]-CAD $65,080 [USD $48,463]) in the fibrinogen concentrate group and CAD $38,790 (USD $28,886) (IQR, CAD $26,180 [USD $19,495]-CAD $70,380 [USD $52,409]) in the cryoprecipitate group. After exclusion of patients who were critically ill before surgery (11%) due to substantial variability in costs, the incremental net benefit of fibrinogen concentrate vs. cryoprecipitate was positive (probability of being cost-effective 86% and 97% at $0 and CAD $2,000 (USD $1,489) willingness-to-pay, respectively). Net benefit was highly uncertain for nonelective and patients with critical illness.
-
5.
Impact of cardiopulmonary bypass duration on efficacy of fibrinogen replacement with cryoprecipitate compared with fibrinogen concentrate: a post hoc analysis of the Fibrinogen Replenishment in Surgery (FIBRES) randomised controlled trial
Bartoszko J, Martinez-Perez S, Callum J, Karkouti K
British journal of anaesthesia. 2022
Abstract
BACKGROUND Coagulopathy in cardiac surgery is frequently associated with acquired hypofibrinogenaemia, which can be treated with either purified fibrinogen concentrate (FC) or cryoprecipitate. Because the latter is not purified and therefore contains additional coagulation factors, it is thought to be more effective for treatment of coagulopathy that occurs after prolonged cardiopulmonary bypass (CPB). We examined the impact of CPB duration on the efficacy of the two therapies in cardiac surgery. METHODS This was a post hoc analysis of the Fibrinogen Replenishment in Surgery (FIBRES) RCT comparing FC (4 g) to cryoprecipitate (10 U) in adult patients undergoing cardiac surgery and experiencing bleeding with acquired hypofibrinogenaemia (n=735). The primary outcome was allogeneic blood products transfused within 24 h after CPB. Subjects were stratified by CPB duration (≤120, 121-180, and >180 min). The interaction of treatment assignment with CPB duration was tested. RESULTS Subjects with longer CPB duration experienced more bleeding and transfusion. With CPB time ≤120 min (FC, n=134; cryoprecipitate, n=146), the ratio of least-squares means between the FC and cryoprecipitate groups for total allogeneic blood products at 24 h was 0.90 (one-sided 97.5% confidence interval [CI]: 0.00-1.12); P=0.004. For subjects with CPB time 121-180 min, it was 1.00 ([one-sided 97.5% CI: 0.00-1.22]; P=0.03], and for CPB time >180 min it was 0.91 ([one-sided 97.5% CI: 0.00-1.12]; P=0.005). Results were similar for all secondary outcomes, with no interaction between treatment and CPB duration for all outcomes. CONCLUSIONS The haemostatic efficacy of FC was non-inferior to cryoprecipitate irrespective of CPB duration in cardiac surgery. CLINICAL TRIAL REGISTRATION NCT03037424.
-
6.
Does Intraoperative Fibrinogen Affect Blood Loss or Transfusion Practice After Aortic Arch Surgery: A Prematurely Ended Randomized Trial
Vlot EA, Hackeng CM, Aper SJA, Sonker U, Heijmen RH, van Dongen EPA, Noordzij PG
Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis. 2022;28:10760296221144042
Abstract
Cardiovascular surgery is often complicated by significant bleeding due to perioperative coagulopathy. The effectiveness of treatment with fibrinogen concentrate to reduce the perioperative blood transfusion rate after thoracic aortic replacement surgery in prior studies has shown conflicting results. Therefore, we conducted a double-blind randomized controlled trial to investigate if a single dose of intraoperative fibrinogen administration reduced blood loss and allogeneic transfusion rate after elective surgery for thoracic arch aneurysm with deep hypothermic circulatory arrest. Twenty patients were randomized to fibrinogen concentrate (N = 10) or placebo (N = 10). The recruitment of study patients was prematurely ended due to a low inclusion rate. Perioperative transfusion, 5-minute bleeding mass after study medication and postoperative blood loss were not different between the groups with fibrinogen concentrate or placebo. Due to small volumes of postoperative blood loss and premature study termination, a beneficial effect of fibrinogen concentrate on the number of blood transfusions could not be established. However, treatment with fibrinogen efficiently restored fibrinogen levels and clot strength to preoperative values with a more effective preserved postoperative thrombin generation capacity. This result might serve as a pilot for further multicenter studies to assess the prospective significance of automated and standardized thrombin generation as a routine assay for monitoring perioperative coagulopathy and its impact on short- and long-term operative results.
-
7.
A Randomized Pilot Trial Assessing the Role of Human Fibrinogen Concentrate in Decreasing Cryoprecipitate Use and Blood Loss in Infants Undergoing Cardiopulmonary Bypass
Tirotta, C. F., Lagueruela, R. G., Gupta, A., Salyakina, D., Aguero, D., Ojito, J., Kubes, K., Hannan, R., Burke, R. P.
Pediatric Cardiology. 2022;43(7):1444-1454
Abstract
The objective of this study was to determine whether treatment with human fibrinogen concentrate decreases the need for component blood therapy and blood loss in neonate and infant patients undergoing cardiopulmonary bypass. Pediatric patients (N = 30) undergoing elective cardiac surgery were randomized to receive human fibrinogen concentrate or placebo following cardiopulmonary bypass termination. The primary endpoint was the amount of cryoprecipitate administered. Secondary endpoints included estimated blood loss during the 24 h post-surgery; perioperative blood product transfusion; effects of fibrinogen infusion on global hemostasis, measured by laboratory testing and rotational thromboelastometry; and adverse events. No clinically significant differences were identified in baseline characteristics between groups. A significantly lower volume of cryoprecipitate was administered to the treatment group during the perioperative period [median (interquartile range) 0.0 (0.0-0.0) cc/kg vs 12.0 (8.2-14.3) cc/kg; P < 0.0001] versus placebo. No difference was observed between treatment groups in blood loss, laboratory coagulation tests, use of other blood components, or incidence of adverse events. FIBTEM amplitude of maximum clot firmness values was significantly higher among patients treated with human fibrinogen concentrate versus placebo (P ≤ 0.0001). No significant differences were observed in post-drug HEPTEM, INTEM, and EXTEM results. Human fibrinogen concentrate (70 mg/kg) administered after the termination of cardiopulmonary bypass reduced the need for transfusion with cryoprecipitate in a neonate and infant patient population.ClinicalTrials.gov identifier: NCT02822599.
-
8.
Efficacy and safety of fibrinogen administration in acute post-traumatic hypofibrinogenemia in isolated severe traumatic brain injury: A randomized clinical trial
Sabouri M, Vahidian M, Sourani A, Mahdavi SB, Tehrani DS, Shafiei E
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia. 2022;101:204-211
-
-
-
-
Editor's Choice
Abstract
AIM: This study was conducted to evaluate clinical outcomes after fibrinogen administration in hypofibrinogenemia following severe traumatic brain injury. BACKGROUND Post traumatic coagulopathy (PTC) is a common but devastating medical condition in patients with severe head injury. Hypofibrinogenemia is considered as an indicator for poor clinical outcomes in traumatic brain injury (TBI). METHODS In this randomized clinical trial (RCT), primarily 137 patients with severe traumatic brain injury (Glasgow coma scale score: GCS < 9) were enrolled. Thereafter, their plasma fibrinogen level was measured. The patients with primary hypofibrinogenemia (<200 mg/dL) with no concurrent coagulopathy were randomly allocated into fibrinogen-receiving (n = 50) and control (n = 54) groups. P-value < 0.05 was considered as statistically significant. RESULTS Seventy-one patients were analyzed in the final step of the study. The mean value for age in fibrinogen and control groups was 25.64 ± 10.71 and 28.91 ± 12.25 years old, respectively. Male - female patients in both groups were equally distributed. In the fibrinogen receiving group, GCS scores were significantly higher after 24, 48, and 72 h compared to the control group (p = 0.000). Hematoma expansion was better controlled in the fibrinogen receiving group (p = 0.000). Notably, the number needed to treat (NNT) for fibrinogen infusion and hematoma expansion control was 2.3. Glasgow outcome scale-extended (GOSE) was significantly better in the fibrinogen group (p = 0.25). Multiple regression tests showed intracerebral hematoma (ICH) and severe brain edema had the most detrimental effect on GOSE outcomes. The need for cranial surgery, hospital stay duration, mechanical ventilator dependency, in hospital and 90-day post discharge mortality rates were similar in both study groups. CONCLUSION In severe TBI, hypofibrinogenemia correction (>200 mg/dL) could improve GOSE, GCS score progression within 3 days after primary head injury and hematoma expansion controllability.
PICO Summary
Population
Patients with hypofibrinogenemia following severe traumatic brain injury (n= 104).
Intervention
Fibrinogen (fibrinogen group, n= 50).
Comparison
No fibrinogen (control group, n= 54).
Outcome
In the fibrinogen receiving group, Glasgow coma scale score scores were significantly higher after 24, 48, and 72 hours compared to the control group. Haematoma expansion was better controlled in the fibrinogen receiving group. The number needed to treat for fibrinogen infusion and haematoma expansion control was 2.3. Glasgow outcome scale-extended (GOSE) was significantly better in the fibrinogen group. Multiple regression tests showed intracerebral haematoma and severe brain oedema had the most detrimental effect on GOSE outcomes. The need for cranial surgery, hospital stay duration, mechanical ventilator dependency, in hospital and 90-day post discharge mortality rates were similar in both study groups.
-
9.
Is Intra-Articular Administration of Fibrinogen Effective in Postoperative Total Knee Arthroplasty Blood Loss? A Randomized Clinical Trial
Janatmakan F, Javaherforooshzadeh F, Khorrami M, Jarirahmadi S, Khademali H
Anesthesiology and pain medicine. 2021;11(1):e107431
Abstract
OBJECTIVES The purpose of this study was to evaluate the effect of intra-articular injection of fibrinogen on postoperative bleeding following total knee arthroplasty. METHODS A double-blind randomized clinical trial was conducted on 40 patients aged 40 - 70 years under spinal anesthesia candidate for total knee arthroplasty in Golestan hospital, Ahwaz, Iran, in 2017-2018. Patients were divided into fibrinogen intra-articular injection (n = 20) and control (n = 20) groups. The amounts of blood loss and blood transfusion requirement were recorded. Hemoglobin (Hb), hematocrit (HCT), international normalized ratio (INR), platelet (PLT), prothrombin time (PT), and partial thromboplastin time (PTT) were recorded before and after the surgery. RESULTS There was no significant difference in the average amount of intraoperative blood loss between the groups (P > 0.05). The average amount of blood loss 24 hours after the surgery was significantly lower in the fibrinogen group than in the control group (fibrinogen group 350.61 ± 120.32 cc; control group 540.00 ± 170.21 cc; P = 0.0002). There were significant differences in transfusion between the groups (fibrinogen group 250 ± 20 cc; control group 350 ± 50 cc; P < 0.0001). There was a significant difference between the two groups in 24 h postoperative Hb and HCT (P < 0.001). CONCLUSIONS Intra-articular fibrinogen administration may reduce acute bleeding and can be used as an effective intervention to prevent further bleeding and the need for transfusion in patients undergoing total knee arthroplasty.
-
10.
Comparison of Published Guidelines for the Diagnosis and the Management of Vaccine-Induced Immune Thrombotic Thrombocytopenia
Zazzeron L, Rosovsky RP, Bittner EA, Chang MG
Critical care explorations. 2021;3(9):e0519
Abstract
The development of thrombocytopenia and thrombosis after the administration of the AstraZeneca and Johnson & Johnson/Janssen vaccines has been recently described. This new condition has been called vaccine-induced immune thrombotic thrombocytopenia. The objective of this review is to summarize the clinical characteristics and therapeutic options of vaccine-induced immune thrombotic thrombocytopenia based on available published case series. Furthermore, we provide a comparison of the diagnostic pathway and treatment recommendations provided by six major medical societies. DATA SOURCES We searched MEDLINE, PubMed, and Cochrane Central Register of Controlled Trials databases. STUDY SELECTION We included case series and case reports on patients who developed vaccine-induced immune thrombotic thrombocytopenia. We also included guidelines for the diagnosis and management of vaccine-induced immune thrombotic thrombocytopenia from major medical societies. DATA EXTRACTION We examined baseline risk factors, symptoms, physical signs, laboratory and imaging findings, and treatment in patients with vaccine-induced immune thrombotic thrombocytopenia reported in the case series. We also analyzed the diagnostic and treatment recommendations provided by major societal guidelines on the management of vaccine-induced immune thrombotic thrombocytopenia. DATA SYNTHESIS Patients who developed vaccine-induced immune thrombotic thrombocytopenia were more likely to be young women (age 20-50) who were given the AstraZeneca or Johnson & Johnson/Janssen 4-28 days prior to presentation. Patients showed signs, symptoms, and imaging findings consistent with cerebral venous sinus thrombosis and splanchnic thrombosis. Laboratory findings showed thrombocytopenia, low fibrinogen, and elevate d-dimer levels, while positive platelet factor 4 antibodies were always positive. Major societal guidelines recommend avoidance of heparin and platelets. Treatment with nonheparin anticoagulants and IV immunoglobulin is also recommended. CONCLUSIONS Vaccine-induced immune thrombotic thrombocytopenia is a rare but highly morbid complication related to the administration of the AstraZeneca and Johnson & Johnson/Janssen vaccines. Clinicians should be prepared for the early identification of patients with suspicious symptoms and prompt treatment should be initiated to avoid catastrophic deterioration. Major societal guidelines provide useful recommendations for the diagnosis and management of patients with vaccine-induced immune thrombotic thrombocytopenia.