scholarly journals Platelet Function Changes during Neonatal Cardiopulmonary Bypass Surgery: Mechanistic Basis and Lack of Correlation with Excessive Bleeding

2019 ◽  
Vol 120 (01) ◽  
pp. 094-106 ◽  
Author(s):  
Nicole M. J. Zwifelhofer ◽  
Rachel S. Bercovitz ◽  
Regina Cole ◽  
Ke Yan ◽  
Pippa M. Simpson ◽  
...  

AbstractThrombocytopenia and platelet dysfunction induced by extracorporeal blood circulation are thought to contribute to postsurgical bleeding complications in neonates undergoing cardiac surgery with cardiopulmonary bypass (CPB). In this study, we examined how changes in platelet function relate to changes in platelet count and to excessive bleeding in neonatal CPB surgery. Platelet counts and platelet P-selectin exposure in response to agonist stimulation were measured at four times before, during, and after CPB surgery in neonates with normal versus excessive levels of postsurgical bleeding. Relative to baseline, platelet counts were reduced in patients while on CPB, as was platelet activation by the thromboxane A2 analog U46619, thrombin receptor activating peptide (TRAP), and collagen-related peptide (CRP). Platelet activation by adenosine diphosphate (ADP) was instead reduced after platelet transfusion. We provide evidence that thrombocytopenia is a likely contributor to CPB-associated defects in platelet responsiveness to U46619 and TRAP, CPB-induced collagen receptor downregulation likely contributes to defective platelet responsiveness to CRP, and platelet transfusion may contribute to defective platelet responses to ADP. Platelet transfusion restored to baseline levels platelet counts and responsiveness to all agonists except ADP but did not prevent excessive bleeding in all patients. We conclude that platelet count and function defects are characteristic of neonatal CPB surgery and that platelet transfusion corrects these defects. However, since CPB-associated coagulopathy is multifactorial, platelet transfusion alone is insufficient to treat bleeding events in all patients. Therefore, platelet transfusion must be combined with treatment of other factors that contribute to the coagulopathy to prevent excessive bleeding.

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3534-3534
Author(s):  
Andrew L. Frelinger ◽  
Anja J Gerrits ◽  
Michelle A. Berny-Lang ◽  
Travis Brown ◽  
Sabrina L. Carmichael ◽  
...  

Abstract Background Immune thrombocytopenia (ITP) patients with similarly low platelet counts differ in their tendency to bleed. Aim To determine if differences in platelet function in ITP patients with similarly low platelet counts partly account for the variation in bleeding tendency. Methods The relationship between bleeding scores and platelet function markers was investigated in a single center cross-sectional study of pediatric patients with ITP. Following informed consent, blood was collected from ITP patients and bleeding was graded using the Buchanan and Adix Score (J Pediatr 2002) at routine clinic visits or while admitted to the hospital. Bleeding scores were obtained by one of three hematologists blinded to platelet function results, and investigators performing platelet function tests were blinded to clinical results. Platelet function was assessed by whole blood flow cytometric measurement of unstimulated, ADP- or TRAP-stimulated platelet surface activated GPIIb-IIIa (as measured by PAC1 binding), P-selectin, and GPIb and by unstimulated, convulxin-, or ADP plus TRAP-stimulated platelet surface phosphatidylserine expression (as determined by annexin V binding). Platelet count, immature platelet fraction (IPF) and mean platelet volume (MPV) were determined by a Sysmex XE-2100, and platelet forward angle light scatter (FSC) was measured by flow cytometry. Results Platelet function and bleeding scores were evaluated in 34 consecutive consenting pediatric ITP patients (16 female, 18 male, age 9.7 ± 5.7 years [mean ± SD]). ITP was newly diagnosed (< 3 months) in 10 patients, persistent (3 -- 12 months) in 7 patients, and chronic (>12 months) in 17 patients. Platelet count at the time of the blood draw was 47 ± 55 x 109/L. The median bleeding score on day of blood draw was 1 (range 0 to 4). By univariate analysis, higher IPF, and lower platelet count were significantly associated with a higher bleeding score (odds ratio [OR] >1, p<0.05) but MPV was not. Multiple measures of platelet function were associated with bleeding scores by univariate analysis: higher levels of platelet FSC (a measure affected by multiple variables including size) surface GPIb on unstimulated, ADP- or TRAP-stimulated platelets, surface P-selectin on unstimulated platelets, and platelet FSC were associated with increased odds for higher bleeding scores (ORs each >1, p<0.05), while higher ADP- and TRAP-stimulated platelet surface activated GPIIb-IIIa and P-selectin were associated with reduced odds of higher bleeding scores (ORs each <1, p<0.05). After adjustment for platelet count, higher levels of platelet surface P-selectin on unstimulated platelets, GPIb on TRAP-stimulated platelets, and FSC remained significantly associated with increased odds for higher bleeding scores (Figure), but IPF did not. Similarly, after adjustment for platelet count, higher TRAP-stimulated percentage of P-selectin and activated GPIIb-IIIa positive platelets remained significantly associated with reduced odds of higher bleeding scores (Figure). These findings were independent of recent ITP-related treatment. Conclusions In this study of pediatric ITP patients, we identified selected platelet function markers which, independent of platelet count, are associated with increased (platelet FSC, platelet surface P-selectin on unstimulated platelets, and GPIb on TRAP-stimulated platelets) or decreased (TRAP-stimulated percent P-selectin and GPIIb-IIIa positive platelets) odds of high bleeding scores. Possible hypotheses to explain these associations are as follows: 1) Increased P-selectin on unstimulated platelets demonstrates in vivo platelet activation, possibly as a consequence of the recent bleeding. 2) Because platelet activation results in a reduction in platelet surface GPIb and increases in platelet surface activated GPIIb-IIIa and P-selectin, the ORs associated with all of these markers could be explained by reduced ability of platelets in patients with higher bleeding scores to respond to agonists. 3) While platelet FSC is partly related to size, the finding that MPV and IPF, adjusted for platelet count, were not associated with bleeding score suggests that factors other than size account for the association of platelet FSC with higher bleeding scores. Further study is required to validate these findings and determine if differences in platelet function are associated with future risk for bleeding. Disclosures: Off Label Use: Eltrombopag was given to WAS/XLT patients for treatment of thrombocytopenia. Neufeld:Shire: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Apopharma: Consultancy. Michelson:Sysmex: Honoraria.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3150-3150
Author(s):  
Oliver Meyer ◽  
Rudolf Schlag ◽  
Thomas Stauch ◽  
Bastian Fleischmann ◽  
Marcel Reiser ◽  
...  

Abstract Background: Immune thrombocytopenia (ITP) is an acquired autoimmune disorder with increased platelet destruction and impaired platelet production. Patients present with bleeding complications of various severity. Another common symptom of ITP is fatigue, which can severely affect patient's quality of life. Eltrombopag (EPAG) is an oral thrombopoietin receptor agonist, which is proved to be effective and safe in the treatment of ITP. In Europe, it is approved for the therapy of patients who were diagnosed with ITP at least 6 months ago and who have not responded to other treatments. Here we present data from the 4 th interim analysis of the RISA study. Methods: RISA is a prospective multicenter non-interventional trial in Germany. It was launched in December 2015, and it will be continued until December 2023. In accordance with the inclusion criteria, adults with persisting or chronic pITP (primary ITP) have been enrolled. Patients with pre-treatment could only be included if it was terminated 4 weeks prior to the patient's consent to participate in the study. Exclusion criteria comprised pregnancy, hepatitis C infection and severe aplastic anaemia. Dosage of EPAG and treatment of patients follows the SmPC and the routine of treating physicians. According to the study protocol, patient questionnaires must be completed at 0,1,3,6,9,12,18 and 24 months. Fatigue is assessed using the FACIT-F score, which includes a score range from 0 to 52, with score values &lt;30 indicating severe fatigue. Statistical elaboration is predominantly descriptive. Calculations of confidence intervals and significance values are performed only for explorative purposes. Results: Data cutoff for this 4 th interim analysis was 23.02.2021. 275 patients were enrolled. 261 of them received at least one dose of EPAG and completed one post baseline assessment. Mean duration of participation was 5.2 years. Mean±SD age was 62.7±17.6 years. 54.8% of the patients were female. Median (range) duration of ITP at baseline was 5.3 (0.0-44.9) years. Comorbidity was present in 80.5% of all patients. 79 (28.7%) patients completed all scheduled visits before data cutoff. Median treatment duration was 395.0 days. Treatment with EPAG was carried out at a median dosage of 50 mg daily. In 255 patients, baseline platelet counts were available. The proportion of patients with a platelet count ≥50x10 9/L was 30.6% at baseline. With EPAG treatment, it increased to 75.4% within the first month (N=224) and to 89.0% within 24 months (N=73) from baseline. 12.6% of the patients who completed at least one assessment visit after baseline were pre-treated with the thrombopoietin receptor agonist romiplostim. Within this subgroup as well, platelet counts responded well to EPAG treatment. In 35.6% of patients, at least one bleeding event had occurred in the 12 months prior to baseline. During EPAG therapy, the incidence of bleeding events per patient year was reduced from 1.40 before baseline to 0.60 and 0.13 within the first and second treatment year respectively. This corresponds to a relative reduction in bleeding events of 57% and 91% respectively. Over the entire two years treatment period, the average incidence of bleeding events per patient year accounted for 0.44, which is 69% below the incidence at baseline. Bleeding events were mostly of low severity. (Tab.) Median FACIT-F score was 37.0 at baseline (N=202; mean 36.0±11.0) and 42.5 after 24 months (N=48; mean 38.1±12.1). This difference was not statistically significant. According to exploratory calculations, severity of fatigue was not correlated to platelet count, hemoglobin concentration or incidence of bleeding events. Discussion: In line with previously published randomized controlled trials (Birocchi et al. Platelets 2021), this non-interventional study confirmed the effectiveness of EPAG in adults with persistent or chronic ITP in a routine care setting. During treatment with EPAG, the prevalence and severity of thrombocytopenia, as well as the incidence of bleeding events, decreased. We could also confirm that fatigue is a significant issue in patients with ITP. A FACIT-F score of 37.0 is comparable to average score values in cancer patients (Montan et al. Value Health 2018). Under treatment with EPAG, we observed a decrease in fatigue that was clinically relevant but not statistically significant. Further research is needed to explore possible additional effects of EPAG, for example on fatigue. Figure 1 Figure 1. Disclosures Meyer: Swedish Orphan Biovitrum: Consultancy, Honoraria; Grifols: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Stauch: Novartis: Honoraria, Research Funding; Amgen: Honoraria. Willy: Novartis Pharma: Current Employment.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4293-4293
Author(s):  
Lakshminarayanan Nandagopal ◽  
Muthu Veeraputhiran ◽  
Tania Jain ◽  
Ayman Soubani ◽  
Charles A. Schiffer

Abstract Introduction Prophylactic platelet transfusions are often performed prior to bronchoscopy or broncho-alveolar lavage (BAL) to prevent bleeding in thrombocytopenic patients. There is a paucity of data to validate this approach, with a platelet transfusion threshold of <50,000/mm3 largely based on expert opinion. We conducted a retrospective study on the incidence of bleeding complications in thrombocytopenic patients undergoing bronchoscopy. Methods We identified 150 consecutive patients with platelet counts <100,000/mm3 who underwent bronchoscopy and/or BAL from January 2009 to May 2014 at our institution. Bronchoscopies performed in patients with frank hemoptysis and trans-bronchial lung biopsy procedures were excluded. Patient characteristics, underlying diagnosis, platelet count prior to bronchoscopy, administration of platelet transfusions and bronchoscopy details were recorded. Factors affecting bleeding risk including presence of renal dysfunction (defined as BUN >30 and/or Cr>2.0) and coagulation studies (PT, PTT, INR) were identified. The British Thoracic Society guidelines1 were used to categorize bleeding as a result of bronchoscopy. Data were analyzed using descriptive statistics. Results The median age was 59 years (range 27-90), with two-thirds of patients (63%) being male. One hundred and seventeen (78%) patients had underlying malignancy and 55 (37%) had thrombocytopenia related to malignancy. Fellows and residents under the supervision of a bronchoscopy certified attending performed all but 4 of the bronchoscopies. Infection (40%) was the primary indication for bronchoscopy with BAL performed in 127 (85%) patients. Fifty-eight of 89 (65%) patients with baseline platelet counts <50,000/mm3 received prophylactic transfusions compared to 8% of those with platelet counts >50,000/mm3. The platelet count did not rise to >50,000//mm3 in many transfused patients. Seventy patients (47%) had counts <50,000/mm3 and eighty patients (53%) had counts >50,000/mm3 at the time of bronchoscopy. 49% were receiving immunosuppressive medications, 45% had renal dysfunction and 8% had INR >1.5. Bloody lavage that resolved spontaneously without continuous suctioning (Grade 0) was observed in 9 (6%) patients. Bleeding that required continuous suctioning but then resolved spontaneously (Grade 1) was noted in 1 patient with a platelet count of 61,000/mm3. Of 10 total bleeding events, 7 occurred in patients who were intubated. Two additional patients with platelet counts of 30,000/mm3 and 53,000/mm3 had diffuse alveolar hemorrhage, which was present before bronchoscopy. “Old” blood and blood clots were observed in 6 patients. Discussion The low incidence of bleeding complications from bronchoscopy +/- BAL even in patients with platelet counts <30,000/mm3 (3 episodes in 31 patients, all grade 0) demonstrates that bronchoscopy can be safely done in severely thrombocytopenic patients. Adopting a lower threshold for prophylactic transfusions could save a considerable number of platelet units and translate into significant cost savings and decreased risk of transfusion-related complications. Table 1 Platelet count, transfusion history and bleeding complications during bronchoscopy Platelet count at the time of bronchoscopy Number (n) and percentage (%) of patients who underwent bronchoscopy Number of patients who received prior platelet transfusion Bleeding during bronchoscopy n % 0-15,000/mm3 9 6% (9/150) 5 Grade 0=1 pt 16-29 22 15% 16 Grade 0=2 pts 30-39 17 11% 9 Grade 0=1 pt 40-49 22 15% 9 Grade 0=3 pts 50-75 44 29% 14 Grade 1=1 pt 76-100 36 24% 10 Grade 0=2 pts Total 150 63 Grade 0=9 pts, Grade 1=1 pt. 1.Du Rand IA, Blaikley J, Booton R, et al. British Thoracic Society guideline for diagnostic flexible bronchoscopy in adults: accredited by NICE. Thorax. 2013:68 Suppl 1:i1-i44 Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2015 ◽  
Vol 126 (11) ◽  
pp. 1367-1378 ◽  
Author(s):  
Anja J. Gerrits ◽  
Emily A. Leven ◽  
Andrew L. Frelinger ◽  
Sophie L. Brigstocke ◽  
Michelle A. Berny-Lang ◽  
...  

Key Points Platelet function in WAS/XLT, measured by agonist-induced surface-activated GPIIb-IIIa and P-selectin, is proportional to platelet size. Eltrombopag increased platelet counts, but did not improve platelet activation, in most WAS/XLT patients.


2011 ◽  
Vol 105 (S 06) ◽  
pp. S67-S74 ◽  
Author(s):  
Marco Cattaneo

SummaryP2Y12, one of the two platelet receptors for adenosine diphosphate (ADP), plays a central role in platelet function. Defects of P2Y12 should be suspected when ADP, even at high concentrations (≥10 μM), is unable to induce full, irreversible platelet aggregation. Patients with congenital P2Y12 defects display a mild-to-moderate bleeding diathesis of variable severity, characterised by mucocutaneous bleeding and excessive post-surgical and post-traumatic blood loss. Drugs that inhibit P2Y12 are potent antithrombotic drugs, attesting the central role played by P2Y12 in platelet thrombus formation. Clopidogrel, the most widely used drug that inhibits P2Y12, is effective both in monotherapy and in combination with acetylsalicylic acid (ASA). Its most important drawback is the inability to inhibit adequately P2Y12-dependent platelet function in about 1/3 of patients, at the recommended therapeutic doses. The incidence of bleeding events is similar in ASA-treated and clopidogrel-treated patients; however, the combination of ASA and clopidogrel causes more bleeding than each drug in monotherapy. Compared to clopidogrel, new drugs inhibiting P2Y12, such as prasugrel and ticagrelor, decrease the risk of cardiovascular events and increase the risk of bleeding complications, because they adequately inhibit P2Y12-dependent platelet function in the vast majority of treated patients.


1999 ◽  
Vol 19 (04) ◽  
pp. 168-175 ◽  
Author(s):  
M. Weippert-Kretschmer ◽  
V. Kretschmer

SummaryPerioperative bleeding complications due to disorders of primary haemostasis are often underestimated. Routine determination of primary haemostasis is still problematic. The in vivo bleeding time (BT) shows low sensitivity and high variability. In this contribution the results and experiences with the IVBT having been obtained in various studies and during 10 years of routine use are reported. Patients and Methods: Blood donors before and after ASA ingestion, patients with thrombocytopenia as well as congenital and acquired platelet function disorders. Monitoring of desmopressin efficacy. IVBT with Thrombostat 4000 (tests with CaCl2 = TST-CaCl2 and ADP = TST-ADP) and PFA-100 (test cartridges with epinephrine = PFA-EPI and ADP = PFA-ADP). Results and Conclusions: IVBT becomes abnormal with platelet counts <100,000/μl. With platelet counts <50,000/μl the results are mostly outside the methodical range. IVBT proved clearly superior to BT in von Willebrand syndrome (vWS). All 16 patients with vWS were detected by PFA-EPI, whereas with BT 7 of 10 patients with moderate and 1 of 6 patients with mild forms of vWS were spotted. The majority of acquired and congenital platelet function disorders with relevant bleeding tendency were detectable by IVBT. Sometimes diagnostic problems arose in case of storage pool defect. Four to 12 h after ingestion of a single dose of 100 mg ASA the TST-CaCl2 became abnormal in all cases, the PFA-EPI only in 80%. However, the ASA sensitivity of TST-CaCl2 proved even too high when looking for perioperative bleeding complications in an urological study. Therefore, the lower ASS sensitivity of the PFA-100 seems to be rather advantageous for the estimation of a real bleeding risk. The good efficacy of desmopressin in the majority of cases with mild thrombocytopenia, congenital and acquired platelet function disorders and even ASS-induced platelet dysfunction could be proven by means of the IVBT. Thus IVBT may help to increase the reliability of the therapy. However, the IVBT with the PFA-100 is not yet fully developed. Nevertheless, routine use can be recommended when special methodical guidelines are followed.


Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1150
Author(s):  
Alberto Zanetto ◽  
Marco Senzolo ◽  
Elena Campello ◽  
Cristiana Bulato ◽  
Sabrina Gavasso ◽  
...  

Hyper-functional platelets are being proposed as a potential therapeutic target in multiple cancers. Whether this can be considered in patients with cirrhosis and hepatocellular carcinoma (HCC) is unknown as their platelet function has not yet been investigated. We evaluated platelet function in cirrhosis patients with HCC. Patients with cirrhosis with and without HCC were prospectively recruited. Platelet aggregation, a marker of platelet function, was assessed by impedance aggregometry with adenosine diphosphate (ADP), arachidonic acid (ASPI), and thrombin (TRAP) stimulation. Plasmatic levels of Von Willebrand factor antigen (VWF) were also determined. One-hundred patients were recruited (50 cirrhotics with and 50 without HCC). Cirrhosis severity by Child class and platelet count were comparable between cirrhotics with and without HCC. Cirrhotics with HCC had higher ADP- (45 vs. 28; p < 0.001), ASPI- (47 vs. 28; p < 0.001), and TRAP- (85 vs. 75; p = 0.01) induced platelet aggregation than cirrhotics without HCC, all indicative of platelet hyper-function. The relatively increased platelet aggregation in patients with HCC was confirmed after adjusting the analysis for platelet count/severity of thrombocytopenia. Levels of VWF were higher in patients with vs. without HCC (348 vs. 267; p = 0.006), particularly in compensated cirrhosis. In patients with cirrhosis, HCC is associated with increased platelet aggregation and higher VWF. The clinical implications of these findings deserve further investigation.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2096-2096
Author(s):  
Eric Mou ◽  
Colin Murphy ◽  
Jason Hom ◽  
Lisa Shieh ◽  
Neil Shah

Introduction Platelets are transfused prophylactically to prevent hemorrhage in a variety of patient populations. However, guidelines indicate that prophylactic platelet transfusions in patients with platelet counts above 50k/uL are usually not indicated, with notable exceptions including those undergoing neurological or cardiac bypass surgery. Common minor procedures such as paracentesis, central line placement, and lumbar puncture have been safely performed at platelet counts below 50k/uL. Despite this evidence, our institution incurred approximately 10 million dollars (USD) in direct platelet costs in 2017, with nearly 40% of platelet transfusions are occurring when the patient's platelet count exceeded 50k/uL. Given the significant financial impact of, and potential adverse effects associated with inappropriate platelet transfusion, we implemented a best practice advisory (BPA) in our electronic medical record (EMR) in order to better characterize patterns of platelet transfusion orders in patients with platelet counts >50k/uL. Methods An EMR-embedded BPA was activated in the inpatient hospital setting of a large, tertiary care academic medical center on May 1, 2019, and triggered whenever a platelet transfusion order was placed on an admitted patient whose most recent documented platelet count was >50k/ul. To inform the comparative impact of BPA alerts on provider behavior, alerts were randomized at the patient level to trigger either in standard or silent fashion. For standard alerts, the BPA appeared on-screen, informing the provider that their platelet transfusion order was potentially inappropriate and citing supportive evidence. Providers had the option of following or overriding the alert (Figure 1). In case of alert override, a pre-specified or free text justification was requested. Pre-specified options included upcoming neurosurgery, cardiac bypass surgery, known qualitative platelet defects, or patients taking antiplatelet drugs. Charge data were based on charges for platelet transfusion orders as listed in the hospital charge master. Results From May 1, 2019 to July 30, 2019, the alert fired 181 times (Figure 2). Alerts were silently triggered in 64 (35%) cases. Of the 117 active alerts, 23 (20%) were followed and 94 (80%) were overridden. The most common reasons for alert override included prophylactic transfusions ahead of non-cardiac and non-neurosurgical operations (18%), upcoming cardiac bypass surgery (18%), qualitative platelet defects (12%), active central nervous system (CNS) bleeding (12%), and active non-CNS bleeding (7%). The estimated cost savings associated with followed alerts was $18,170 USD. Discussion Our BPA was effective in reducing instances of platelet transfusion orders by 20% over a three-month period, translating to an estimated annual savings of nearly $70,000 USD in hospital charges. Conversely, the 80% alert override rate indicates that platelet transfusion in patients with platelet counts >50k/uL remains common, occurring in a variety of contexts. Potentially appropriate reasons for platelet transfusions included orders in the setting of cardiovascular bypass surgery, active CNS bleeding, or qualitative platelet defects, representing circumstances in which platelet thresholds are often set higher than 50k/uL. Alternatively, 25% of alert overrides occurred in potentially inappropriate contexts, including patients undergoing non-cardiovascular/non-neurosurgical procedures and patients with non-CNS active bleeding, settings where routinely targeting a platelet threshold >50k/uL is not supported by evidence. As a result of our study's randomized design, future directions include comparative analyses between patient care encounters in which alerts were silently versus visibly triggered, allowing for rigorous determination as to whether providers' interaction with our BPA influences subsequent rates of potentially inappropriate platelet utilization as compared to a control group. Overall, our findings show that platelets are frequently ordered in potentially inappropriate settings, and that reducing these orders imparts significant financial savings. These results provide an impetus for interventions directed at educating providers on appropriate platelet ordering practices, in order to further reduce unnecessary expenditures and optimize patient care. Disclosures No relevant conflicts of interest to declare.


Perfusion ◽  
2009 ◽  
Vol 24 (3) ◽  
pp. 191-197 ◽  
Author(s):  
Kathryn Nardell ◽  
Gail M Annich ◽  
Jennifer C Hirsch ◽  
Cathe Fahrner ◽  
Pat Brownlee ◽  
...  

Background/Objective: There is limited literature documenting bleeding patterns in pediatric post-cardiotomy patients on extracorporeal life support (ECLS). This retrospective review details bleeding complications and identifies risk factors for bleeding in these patients. Methods: Records from 145 patients were reviewed. Patients were divided into excessive (E) and non-excessive (NE) bleeding groups based on blood loss. Results: Excessive bleeding occurred predominantly from 0-6h. Longer CPB duration (NE=174±8min; E=212±16; p=0.02) and lower platelet counts (NE=104.8±50K; E=84.3±41K; p=0.01) were associated with excessive bleeding during the first 6h (p=0.005). Use of intraoperative protamine with normal platelets was associated with decreased bleeding from 7-12h post-ECLS (p=0.002). Most mediastinal exploration occurred >49h post-ECLS, with decreased bleeding post-exploration in E patients. Conclusions: The majority of pediatric post-cardiotomy ECLS bleeding occurs early after support initiation. Longer CPB time and thrombocytopenia increased bleeding 0-6h post-ECLS. Since early bleeding may be coagulopathic in origin, an approach to minimize bleeding includes protamine administration and aggressive blood product replacement with target platelet counts of 100-120K. Surgical exploration should follow if additional hemostasis is necessary.


Blood ◽  
1999 ◽  
Vol 93 (9) ◽  
pp. 3124-3126 ◽  
Author(s):  
Markus Sagmeister ◽  
Lic Oec ◽  
Jürg Gmür

Abstract The threshold for prophylactic platelet transfusions in patients with hypoplastic thrombopenia generally recommended in the standard literature is 20,000 platelets/μL. A more restrictive transfusion policy may be indicated in patients with chronic severe aplastic anemia (SAA) in need of long-term platelet support. We evaluated the feasibility and safety of a policy with low thresholds for prophylactic transfusions (≤5,000 platelets/μL in stable patients; 6,000 to 10,000 platelets/μL in cases with fever and/or hemorrhagic signs) combined with progressive lengthening of transfusion intervals (up to at least 7 days irrespective of the interim course of platelet counts). The study was based on a retrospective analysis of a total of 18,706 patient days with platelet counts ≤10,000/μL in patients with chronic SAA treated (for more than 3 months) on an outpatient basis. Altogether, 1,135 platelet transfusions were given, 88% at counts ≤10,000/μL and 57% at counts ≤5,000/μL. The mean transfusion interval was 10 days. During the period of observation, three major nonlethal bleeding complications occurred, which could be well controlled. We conclude that the restrictive policy with low transfusion thresholds and prolonged transfusion intervals proved feasible and safe in chronic SAA patients.


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