Are Routine Laboratory Investigations Necessary Following Percutaneous Nephrolithotomy?

OBJECTIVE: To determine how effective routine postoperative blood work is in identifying complications after percutaneous nephrolithotomy (PCNL), the gold standard treatment for large volume stone disease. Although major complication rates are low, hemorrhagic and sepsis-related complications are serious and can occur. Routine post-PCNL complete blood count is routinely performed by most endourologists but may be a low-value practice. METHODS: A retrospective review was performed of all PCNL procedures at our center over a 3-year period. Patient demographic, stone characteristics and postoperative data were collected and analyzed. RESULTS: Three hundred and eighty-five patients (196 female and 189 males) underwent PCNL for the treatment of urolithiasis. Mean age was 55.8 years and mean length of stay in hospital was 1.74 days. Most patients (82.9%) had neither ureteric stent nor percutaneous tube prior to PCNL. Postoperatively, 4 patients (1.0%) required a blood transfusion and 14 patients (3.6%) developed urosepsis. Patients who required either a transfusion or developed urosepsis demonstrated abnormal vital signs (tachycardia, hypotension, or fever) postoperatively. Sixteen patients (4.2%) had normal vital signs but had an extended hospital stay only to monitor abnormal blood work results. None these patients required a transfusion nor developed urosepsis but had a length of stay that was a mean of 1.5 days longer patients with normal postoperative vital signs and blood work. CONCLUSION: Abnormal vital signs alone identified all patients that required transfusion or treatment for urosepsis after PCNL. Routine complete blood count testing postoperatively may not improve detection of infectious or bleeding complications and may prolong hospital admission unnecessarily.

Target Population of Non-deferrable Surgery and Uncontrolled Severe Bleeding Related to Dabigatran.

PURPOSE: This observational study was aimed to identify patients who experienced non-deferrable surgery and/or uncontrolled severe bleeding following dabigatran administration and then are potentially eligible to the use of the specific antidote idarucizumab in a real-world setting. METHODS: From the big Italian real-world database ARCO, a cohort of adult patients treated with dabigatran and hospitalized due to diagnoses attributable to urgent interventions and/or major bleeding was selected in 2014. Baseline characteristics and all-cause hospitalizations, specialist/diagnostic outpatient services, and healthcare costs over the 1-year follow-up were described. RESULTS: Out of 16,756,843 Italian citizens, 271,540 (1.9%) were prescribed with oral anticoagulants, and specifically, 17,450 with dabigatran. Patients identified to be hospitalized for non-deferrable surgery (n = 106) and/or uncontrolled severe bleeding (n = 190) following dabigatran use were 289 (1.7%) [mean age (± SD) 79 ± 7, 50% of female sex]. On average, patients stayed in hospital 13.7 and 17.0 days, respectively. The per patient and per year cost to the Italian National Health System was on average 19,708€ (specifically 1487€ for drugs, of which 311€ for dabigatran, 17,353€ for all-cause hospitalizations, and 869€ for outpatient care), about four times more than the mean healthcare integrated cost of a single patient treated with dabigatran (4775€). CONCLUSIONS: This analysis of the ARCO database reliably describes the population potentially eligible to the dabigatran reversal agent, idarucizumab. These data may be useful for Healthcare Decision Makers to organize, define, and improve present and future emergency healthcare, mainly as starting point for cost-effectiveness analyses of new reversal agents.

Targeted Bleeding Management Reduces the Requirements for Blood Component Therapy in Lung Transplant Recipients.

OBJECTIVE: Lung transplantation is associated with high rates of bleeding and frequent blood transfusion. The authors aimed to determine if point-of-care coagulation testing (POCCT) reduced transfusion requirements. DESIGN, SETTINGS, AND PARTICIPANTS: A before-and-after cohort analysis conducted at a single tertiary referral center. Ninety-three sequential adult patients between January 2010 and January 2014 undergoing isolated lung transplant without preoperative extracorporeal support were analyzed. INTERVENTION: ROTEM and multi-plate POCCT were introduced on July 1, 2012, with an associated algorithm based on the results. MEASUREMENTS AND MAIN RESULTS: Statistically significant decreases in the proportion of patients receiving PRBCs (87% v 65%; p = 0.015), FFP (72% v 30%; p<0.0001) and platelets (70% v 37%; p = 0.002) were found after the intervention. There were small decreases in median chest tube blood loss at 2 hours (300 mLs v 215 mLs; p = 0.03) and 4 hours (440 mLs v 350 mLs; p = 0.050) but not at 12 hours postoperatively. There were no changes in reoperation for bleeding (9% v 4%; p = 0.158) or in-hospital mortality (6% v 2%; p = 0.617). The cost of blood products administered decreased from a median of $3,935.00 to $991.00 (p<0.001). CONCLUSIONS: Use of POCCT in lung-transplant surgery is associated with significant reductions in blood product use and cost. There were no detectable changes in outcome aside from a small decrease in early postoperative bleeding.

[Using a Standardized Questionnaire for Coagulation Assessment in Children Undergoing Tonsillectomy]. / Standardisierte Gerinnungsanamnese vor Tonsillektomie und Adenotomie im Kindesalter.

Introduction A 2006 position paper suggests assessing coagulation status via a standardized questionnaire instead of performing routine coagulation testing for children undergoing tonsillectomy/adenotomy. The aim of the presented study was to evaluate whether this paradigm change led to a change in the incidence of secondary bleeding. Methods Descriptive statistical analysis of existing clinical data was performed to evaluate the incidence and characteristics of secondary bleeding in children after tonsillectomy/adenotomy in 2003 vs. 2009. Result In 2003, 352 children underwent surgery. Secondary bleeding occurred in 25 cases (7.1%), 18, (6.1%) of which required surgical treatment. In 2009, 20 out of 293 children who had undergone tonsillectomy/adenotomy suffered from secondary bleeding, 14 required (4.7%) surgical treatment. There was no significant difference in the incidence of bleeding between those years. In 5 children who suffered from secondary bleeding in 2003, preoperative diagnostic blood coagulation testing was performed, none of them showed abnormal results. Furthermore, none of the diagnostic blood coagulation tests performed after secondary bleeding in both groups showed any abnormalities. Conclusion Using a standardized questionnaire instead of a diagnostic blood coagulation testing for preoperative coagulation assessment does not have an influence on the incidence of secondary bleeding after tonsillectomy/adenotomy. The results of this study suggest that secondary bleeding is not is not caused by abnormal hemostasis.

Relation Between Platelet Count and Platelet Reactivity to Thrombotic and Bleeding Risk: From the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents Study.

Whether the association between platelet count (PC) and thrombotic and bleeding risk is independent of or varies by residual platelet reactivity to antiplatelet therapies is unclear. We sought to investigate the independent and combined effects of PC and platelet reactivity on thrombotic and bleeding risk after coronary artery implantation of drug-eluting stents (DES). Patients enrolled in the prospective, multicenter Assessment of Dual AntiPlatelet Therapy with Drug-Eluting Stents study were stratified by PC tertiles. The study cohort comprised 8,402 patients. By linear regression analysis, lower PC was strongly and independently associated with higher platelet reactive units (PRUs) on clopidogrel. After multivariable adjustment (including PRU and aspirin reactive units), high, but not low, PC tertile was independently associated with higher risk of thrombotic complications, including spontaneous myocardial infarction and stent thrombosis. Although no independent association was observed between PC tertiles and hemorrhagic risk, both high and low PC tertiles were associated with increased risk for all-cause mortality. After stratification of PC tertiles by tertiles of PRUs, the crude risk of thrombotic complications was highest in patients in the high PC and high PRU tertiles. By multivariable adjustment, PRU increases were uniformly associated with higher risk of thrombotic events across PC tertiles, without evidence of interaction. In conclusion, higher PCs and higher PRUs act independently and synergistically in determining thrombotic risk. Alongside PRU, PCs could be a simple hematological parameter to consider for risk stratification and in tailoring duration and potency of pharmacologic platelet inhibition after DES implantation.

A critical appraisal of point-of-care coagulation testing in critically ill patients.

Derangement of the coagulation system is a common phenomenon in critically ill patients, who may present with severe bleeding and/or conditions associated with a prothrombotic state. Monitoring of this coagulopathy can be performed with conventional coagulation assays; however, point-of-care tests have become increasingly attractive, because not only do they yield a more rapid result than clinical laboratory testing, but they may also provide a more complete picture of the condition of the hemostatic system. There are many potential areas of study and applications of point-of-care hemostatic testing in critical care, including patients who present with massive blood loss, patients with a hypercoagulable state (such as in disseminated intravascular coagulation), and monitoring of antiplatelet treatment for acute arterial thrombosis, mostly acute coronary syndromes. However, the limitations of near-patient hemostatic testing has not been fully appreciated, and are discussed here. The currently available evidence indicates that point-of-care tests may be applied to guide appropriate blood product transfusion and the use of hemostatic agents to correct the hemostatic defect or to ameliorate antithrombotic treatment. Disappointingly, however, only in cardiac surgery is there adequate evidence to show that application of near-patient thromboelastography leads to an improvement in clinically relevant outcomes, such as reductions in bleeding-related morbidity and mortality, and cost-effectiveness. More research is required to validate the utility and cost-effectiveness of near-patient hemostatic testing in other areas, especially in traumatic bleeding and postpartum hemorrhage.

Usefulness of thromboelastometry in predicting the risk of bleeding in cirrhotics who undergo invasive procedures.

OBJECTIVES: The management of patients with liver cirrhosis undergoing invasive procedures is controversial and haemostasis assessment using routine laboratory is inappropriate. We evaluated the following: (a) the ability of thromboelastometry to predict the risk of bleeding in cirrhotic patients undergoing invasive procedures and enable a decision on the prophylactic transfusional strategy; (b) the contribution of platelet adhesion and aggregation tests in the assessment of haemostasis. PATIENTS AND METHODS: Seventeen cirrhotic patients undergoing invasive procedures were analyzed retrospectively (training set). To obtain preliminary data, an observational study was carried out in 58 patients (test set). All 75 patients were evaluated by thromboelastometry. Platelet adhesion and aggregation were evaluated in 16 patients using Multiplate, PFA-100 and Light Transmission Aggregometry. Factor VIII was dosed in all patients of the test set. RESULTS: In the training set, thromboelastometry confirmed the haemostatic assessment shown by the conventional test only in 6/17 (35%) patients. In the test set, thromboelastometry identified all patients who had a bleeding event. In patients with a high risk of bleeding, the use of thromboelastometry was cost-effective, reducing the platelet infusions by 64%. Platelet adhesion/aggregation abnormalities were observed in 15/16 (94%) patients, but bleeding events occurred only in 2/15 (13%) patients. CONCLUSION: Thromboelastometry appears to be useful to screen cirrhotic patients undergoing invasive procedures to identify the risk of bleeding and to optimize the transfusional strategy. Adhesion/aggregation tests are not useful in identifying patients at risk of bleeding and their application is not cost-effective.

Assessment Of Hemostatic Condition In Patients After Surgical Trauma.

UNLABELLED: Hemostatic system is designed to maintain blood in a fluid state yet provide important defenses against bleeding when injury occurs to the vessel. During surgery, patients are exposed to hemostatic stress causing complications of either hypercoagulability or hemorrhage. The goal of the present study was to describe the clotting changes in patients who underwent major surgeries especially procoagulant mechanisms. METHODS: 30 patients belonging to both sexes who were undergoing surgery for various reasons were included in the study. Tests to assess the integrity of hemostatic system were conducted. Results: Analysed and expressed in mean and SD. There was a significant (p < 0.05) difference in the hemostatic parameters like bleeding time, clotting time, thrombin time, platelet count and fibrinogen concentration between the preoperative and postoperative periods.

[A WHO concept- patient blood management]. / Ein WHO Konzept - Patient Blood Management.

Blood transfusions are in general considered as lifesaving. Current data and evidence show, that blood transfusions are associated with increased morbidity and mortality, and this apparently dose-dependent. Basic research and results from randomized controlled trials show a causal relationship between blood transfusion and adverse outcome. Based on the current state of knowledge it has to be questioned that blood transfusions are "life-saving" as patients are exposed to an increased risk of disease or death. Furthermore, blood transfusions are more costly than previously assumed. For these reasons novel approaches in the treatment of anemia and bleeding are needed. Patient Blood Management (PBM) allows reduction of transfusion rates by correcting anemia by stimulating erythropoiesis, minimizing perioperative blood loss and optimizing the physiological tolerance of anemia. In 2010 the World Health Organization has claimed PBM to be considered as golden standard. PBM reduces morbidity and mortality by lowering the excessive use of blood transfusions. This concept has partially and successfully been implemented in the University Hospital Balgrist in Zurich.

A l'heure actuelle les transfusions sanguines sont généralement considérées comme salvatrices. Les données actuelles par contre montrent que les transfusions sanguines sont associées, et cela clairement en fonction des doses appliquées, à une morbidité et mortalité augmentées. Outre différentes tentatives d'explication fournies par la recherche fondamentale, les résultats récents d'études contrôlées et randomisées ont clairement démontré qu'il s'agit d'une relation de cause à effet. Pour cela l'opinion que des transfusions sanguines sont salvatrices doit être revue de façon critique car ce traitement peut promouvoir des maladies et même représenter un danger vital. En plus les transfusions sanguines génèrent des coûts beaucoup plus élevés que présumé jusqu'à présent. En cas d'anémie ou de saignement de nouveaux concepts de traitements comme le «patient blood management¼ (PBM) sont indispensables et essentiels. Le PBM réduit la nécessité de transfusions en corrigeant l'anémie par des substances stimulant l'érythropoïèse, en réduisant les pertes sanguines durant l'intervention chirurgicale et en augmentant la tolérance physiologique de l'anémie. Une résolution de l'organisation mondiale de la santé en 2010 exige que le PBM soit considéré comme «le golden standard¼ pour le traitement des patients. La réduction de l'utilisation de produits sanguins peut clairement diminuer la mortalité et morbidité. Depuis que le concept a partiellement été introduit à l'hôpital universitaire Balgrist, Zurich et montre clairement des résultats positifs.

Bleeding risk assessment using whole blood impedance aggregometry and rotational thromboelastometry in patients following cardiac surgery.

Excessive bleeding after cardiopulmonary bypass (CPB) is risk factor for adverse outcomes after elective cardiac surgery (ECS). Differentiating between patients who bleed due to surgical issues and those whose excessive chest tube output (CTO) is due to coagulopathy, remains challenging. Bedside suitable tests to identify hemostatic disturbances and predict excessive bleeding are desirable. The study sought to evaluate prediction of excessive bleeding after ECS using two bedside suitable devices for platelet function and viscoelastic blood clot properties assessment. We enrolled 148 patients (105 male and 43 female) undergoing ECS in a prospective observational study. Patients were characterized as bleeders if their 24 h CTO exceeded the 75th percentile of distribution. Multiple electrode aggregometry (MEA, with ASPI, ADP and the TRAP test) and rotational thromboelastometry (TEM, with ExTEM, HepTEM and FibTEM test), were performed at three time points: preoperatively (T1), during CPB (T2), and after protamine administration (T3). The primary endpoint was CTO and the secondary endpoint was administration of blood products, 30-day and 1 year mortality. The best predictors of increased bleeding tendency were the tests performed after protamine administration (T3). At T3, patients characterized as bleeders had significantly lower MEA ASPI (median, 14 vs. 27 AUC, p = 0.004) and ADP test values (median, 22 vs. 41 AUC, p = 0.002) as well as TEM values expressed in maximum clot firmness after 30 min (MCF 30) for ExTEM (53 vs. 56 mm, p = 0.005), HepTEM (48 vs. 52 mm, p = 0.003) and FibTEM (8 vs. 11 mm, p < 0.001) test. 24 h CTO inversely correlated with both the MEA (ASPI test: r = -0.236, p = 0.004; ADP test: r = -0.299, p < 0.001), and TEM MCF 30 (ExTEM: r = -0.295, p < 0.001; HepTEM: -0.329, p < 0.001; FibTEM: -0.377, p < 0.001) test values. Our study showed that MEA and TEM are useful methods for prediction of excessive bleeding after ECS. In order to prevent excessive postoperative CTO, hemostatic interventions with timely and targeted blood component therapy according to MEA and TEM results should be considered.

Bleeding risk assessment using multiple electrode aggregometry in patients following coronary artery bypass surgery.

Individual variability in the response to antiplatelet therapy (APT), frequently administered preoperatively, has been established by various platelet function assays and could reflect bleeding tendency after coronary artery bypass surgery (CABG). Our hypothesis is that multiple electrode whole-blood aggregometry (MEA) can identify patients at risk for excessive bleeding. We enrolled 211 patients (155 male and 56 female) undergoing isolated CABG in a prospective observational study. Patients were divided into four groups with respect to their preoperative APT management. MEA, using the ASPI and the ADP test, was performed prior to surgery. The primary endpoint was chest tube output (CTO) and the secondary endpoint was perioperative packed red blood cell concentrate (PRBC) administration. Patients were characterized as bleeders if their 24 h CTO exceeded the 75th percentile of distribution. 24 h CTO value of 11.33 ml/kg presented 75th percentile of distribution, thus cut-off value for "bleeder category". The proportion of patients characterized as bleeders was significantly different among the groups in regard to preoperative APT (p = 0.039). Significant differences in both ASPI (p < 0.001) and ADP (p = 0.038) tests were observed between different preoperative APT groups. Significant correlations between the ASPI test (r = -0.170, p = 0.014) and ADP test (r = -0.206, p = 0.003) with 24 h CTO were found. The receiver operating curve revealed an ASPI test value of <20 area under curve (AUC) units (AUC 0.603, p = 0.023) and an ADP test <73 AUC (AUC 0.611, p = 0.009) as a "bleeder" determinant. The proportion of patients transfused with PRBC did not significantly differ among the groups in regard to preoperative APT (p = 0.636). Comparison of the ASPI test values between patients with respect to PRBC administration revealed lower values in the ASPI test in a group of patients transfused with PRBC (mean, 27.88 vs. 40.32 AUC, p = 0.002). Our study showed that MEA is a useful method of predicting CABG patients with excessive postoperative bleeding.

[Algorithm of clinical assessment of the hemostasiogram indices in surgical practice].

On the basis of literature data and personal clinical experience the author gives clinical interpretation of hemostasiogram tests used in clinical practice and an algorithm of the clinical analysis of the hemostasiogram allowing detection of concrete disorders in the hemostasis mechanisms and decision on the pathogenetically substantiated program of therapy for bleedings in surgical practice.

Differential effects of aprotinin and tranexamic acid on outcomes and cytokine profiles in neonates undergoing cardiac surgery.

OBJECTIVE: Factors contributing to postoperative complications include blood loss and a heightened inflammatory response. The objective of this study was to test the hypothesis that aprotinin would decrease perioperative blood product use, reduce biomarkers of inflammation, and result in improved clinical outcome parameters in neonates undergoing cardiac operations. METHODS: This was a secondary retrospective analysis of a clinical trial whereby neonates undergoing cardiac surgery received either aprotinin (n = 34; before May 2008) or tranexamic acid (n = 42; after May 2008). Perioperative blood product use, clinical course, and measurements of cytokines were compared. RESULTS: Use of perioperative red blood cells, cryoprecipitate, and platelets was reduced in neonates receiving aprotinin compared with tranexamic acid (P < .05). Recombinant activated factor VII use (2/34 [6%] vs 18/42 [43%]; P < .001), delayed sternal closure (12/34 [35%] vs 26/42 [62%]; P = .02), and inotropic requirements at 24 and 36 hours (P < .05) were also reduced in the aprotinin group. Median duration of mechanical ventilation was reduced compared with tranexamic acid: 2.9 days (interquartile range: 1.7-5.1 days) versus 4.2 days (2.9-5.2 days), P = .04. Production of tumor necrosis factor and interleukin-2 activation were attenuated in the aprotinin group at 24 hours postoperatively. No differential effects on renal function were seen between agents. CONCLUSIONS: Aprotinin, compared with tranexamic acid, was associated with reduced perioperative blood product use, improved early indices of postoperative recovery, and attenuated indices of cytokine activation, without early adverse effects. These findings suggest that aprotinin may have unique effects in the context of neonatal cardiac surgery and challenge contentions that antifibrinolytics are equivalent with respect to early postoperative outcomes.

[Current coagulation diagnostics in intensive care medicine]. / Aktuelle Gerinnungsdiagnostik in der Intensivmedizin.

In the preoperative setting, a standardized questionnaire on bleeding history cannot be replaced by the Quick test or activated partial thromboplastin time (APTT) measurement. Thrombelastometry provides rapid measurement of coagulation in the intra- and postoperative settings. Besides the Quick test and APTT, thrombelastometry provides information about clot firmness and clot stability. This allows goal-directed management in coagulopathy, which results in a reduction of transfusion of blood products. Furthermore, this can lead to not only an overall reduced length of stay in the hospital, but also in the intensive care unit, thus, contributing to a significant cost reduction.

Preoperative hematological assessment of pediatric patients with cerebral palsy.

OBJECTIVES: Nutritional deficiencies and use of antiepileptic drugs can lead to alterations in the hematological status of children with cerebral palsy (CP), which may increase the risk of intraoperative or postoperative hematological complications. In this retrospective study, we evaluated the preoperative routine blood tests of CP patients with different levels of walking ability, who were scheduled to undergo orthopedic procedures. METHODS: Hemoglobin level, hematocrit, red blood cell count, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red cell distribution width, white blood cell count, platelet count, prothrombin time, activated partial thromboplastin time, and plasma fibrinogen concentration were compared between 62 consecutive CP patients [28 girls, 34 boys; mean age 8.8 years (range 2-16 years)] and 130 consecutive orthopedic patients as control [64 girls, 66 boys; mean age 9.2 years (range 2-16 years)] who did not have any skeletal, cranial, thoracic, abdominal or major soft tissue injuries, or any other infectious, metabolic, hematological or malignant tumor disorders. RESULTS: CP and control groups were similar with regard to the above-mentioned hematological parameters. In the CP group, no difference was found between Gross Motor Function Classification System for Cerebral Palsy (GMFCS) level I/II patients and GMFCS level III/IV patients in terms of these hematological parameters. CONCLUSION: Preoperative blood tests results of pediatric CP patients, walking with or without any supportive devices and undergoing orthopedic interventions, are similar to those of other orthopedic patients. Advanced preoperative hematological tests can only be recommended for CP patients with abnormal blood test results.

A point-of-care assessment of the effects of desmopressin on impaired platelet function using multiple electrode whole-blood aggregometry in patients after cardiac surgery.

BACKGROUND: Blood loss after cardiac surgery can be caused by acquired platelet dysfunction after cardiopulmonary bypass. Monitoring of platelet function is clinically important for the identification of patients experiencing such platelet dysfunction. 1-Deamino-8-D-arginine vasopressin (desmopressin acetate, DDAVP) has been shown to augment platelet function and to reduce blood loss in patients with platelet dysfunction. In this study, we examined the feasibility of whole blood multiple electrode aggregometry (MEA) for the detection of cardiopulmonary bypass-induced platelet dysfunction and investigated its ability to monitor DDAVP treatment. METHODS: Fifty-eight consecutive patients with blood loss exceeding 150 mL/h in the first 2 consecutive hours after cardiac surgery were screened for suspected isolated platelet dysfunction. Twenty-two patients had suspected isolated platelet dysfunction and were enrolled in the study. Platelet dysfunction was assumed if conventional coagulation analyses (platelet count, activated partial thromboplastin time, international normalized ratio, and fibrinogen) did not show abnormal values as defined for transfusion of allogenic blood products, and no surgical cause of bleeding was suspected. Eleven patients received 0.3 microg/kg DDAVP, and 11 patients received no therapy in a nonrandomized manner. MEA was performed after stimulation with thrombin receptor-activating peptide (TRAPtest, 32 microM), adenosine diphosphate (ADPtest, 6.4 microM), and arachidonic acid (ASPItest, 0.5 mM) before and 2 hours after intervention. Conventional laboratory variables were recorded. The Mann-Whitney test was used to detect differences between the groups, and the Wilcoxon test was used to detect differences before and after intervention. RESULTS: All enrolled patients showed platelet dysfunction that manifested as impaired platelet aggregation in MEA before intervention. After the intervention, platelet function improved in the DDAVP group (49 U [30/72 U], median [25th/75th percentile] postintervention vs 15 U [8/21 U] preintervention for the ASPItest [P < 0.001]; 35 U [24/54 U] vs 14 U [7/28 U] for the ADPtest [P = 0.002]; and 85 U [66/115 U] vs 64 U [26/88 U] for the TRAPtest [P = 0.007]). In contrast, MEA remained unchanged in the control group (22 U [10/50 U] postintervention vs 33 U [14/57 U] preintervention for the ASPItest [P = 0.175]; 17 U [12/20 U] vs 14 U [10/28 U] for the ADPtest [P = 0.147]; and 65 U [41/89 U] vs 57 U [30/91 U] for the TRAPtest [P = 0.123]). CONCLUSIONS: Impaired platelet function after cardiac surgery can be assessed at the bedside using MEA. The effect of DDAVP on impaired platelet function can also be detected as significant improvement in platelet aggregation to all activators. This device might be helpful for the identification of patients who may benefit from DDAVP therapy.

Assessment of the risk of bleeding in patients undergoing surgery or invasive procedures: Guidelines of the Italian Society for Haemostasis and Thrombosis (SISET).

SYNOPSIS OF RECOMMENDATIONS: The Italian Society for Thrombosis and Haemostasis (SISET: Società Italiana per lo Studio dell' Emostasi e della Trombosi) promoted the development of a series of guidelines which would adopt evidence-based medicine methodology on clinically relevant problems in the field of haemostasis and thrombosis. The objective of the present guidelines is to provide recommendations for the pre-operative and pre-procedural assessment of the bleeding risk with the aim of reducing the incidence of preventable bleeding complications and limiting laboratory tests to the those necessary. The predictive value of haemostatic tests for bleeding complications after surgery or invasive procedures has been evaluated in prospective or retrospective cohort studies only. All retrieved studies were of low methodological quality with a high potential for bias because none conducted a blinded outcome assessment. In addition, different criteria for the severity of bleeding events and different reference values of the laboratory tests were adopted. The low methodological quality limits the validity of the results of these studies. Some of the clinical queries proposed by the working group were not addressed by the studies available in the literature. The areas with evidence, although of low quality, are the following: general surgery in adults (for history, PT, APTT, platelet count and bleeding time), neurosurgery in adults (for history, PT, APTT, platelet count), adenotonsillectomy in children (for history, PT, APTT, platelet count and bleeding time), invasive procedures in adults (for PT, APTT, platelet count), dental extractions (for the bleeding time only), cataract extraction (for platelet count). No studies are available in children for major surgery other than adenotonsillectomy, neurosurgery and invasive procedures.

[An attempt to evaluate the reliability of coagulation tests in postoperative haemorrhages in patients operated for tonsil disorders]. / Próba oceny wiarygodnosci wyników badan ukladu krzepniecia w kontekscie wystepowania krwawien u chorych po operacjach migdalków gardlowych i podniebiennych.

Postoperative haemorrhage is an important complication of surgical procedures performed on adenoids and tonsils. They occur rarely but they seriously endanger the patients. Determining risk factors of the postoperative haemorrhages might be very important. The aim of the study was to analyze values of coagulation tests' results obtained in the patients prior to the operations, to determine correlation between the values of the results and incidents of postoperative haemorrhages, and to answer the question whether performing the coagulation tests in these patients is cost-effective. Records of 249 patients aged from 2 to 60 (mean 10.1) years treated in our department between January 2007 and May 2008 were analysed retrospectively. Values of activated partial thromboplastin time (APTT), prothrombin/INR ratio and platelet count were analyzed. In 50 (20.1%) individuals coagulation tests' values were elevated, among them APTT results in 48 (19.3%) patients. In 36 (14.5%) of them the results exceeded the normal range by less than 10% and in the remaining 14 (5.6%)--by 10% or more. There were 16 (6,4%) cases of postoperative haemorrhage. 11 (4.4%) of them occurred in the first 24 postoperative hours. In only 3 (1.2%) individuals (with early haemorrhages) the values were elevated, in 2 (0,8%) less than by 10%, in one (0.4%) more than by 10%. No statistically significant correlation between frequency of haemorrhages and the obtained coagulation tests results in the groups of patients was established. Blood tests' performed prior to the operations on adenoids and tonsils have no relevance for the course of the operation and postoperative bleeding event, particularly in children. Blood tests should only be performed in patients with a relevant bleeding history.

Platelet concentrates transfusion in cardiac surgery and platelet function assessment by multiple electrode aggregometry.

BACKGROUND: Platelet dysfunction contributes to the pathophysiology of bleeding complications during and after cardiac surgery. In most surgical institutions, no peri-operative point-of-care monitoring of platelet function is used. We evaluated the usefulness of the Multiplate platelet function analyser based on impedance aggregometry for identifying groups of patients at a high risk of transfusion of platelet concentrates (PC). METHODS: Platelet function parameters were determined in 60 patients before and after routine cardiac surgery. Impedance aggregometry measurements were performed on Multiplate using ADP (ADPtest), collagen (COLtest) and thrombin receptor activating peptide (TRAPtest) as platelet activators. The correlations between the aggregometry results and the transfusion of PC were calculated. The results of the aggregation tests were also divided into tertiles and the differences in PC transfusion between the low and the high tertile were assessed. RESULTS: Low aggregometry delimited groups of patients with significantly higher PC transfusion. In the receiver operating characteristic curve, low pre-operative aggregation in the ADPtest identified patients with high total transfusion of PC (area under the curve 0.74, P=0.001), while the ADPtest performed at the end of the operation identified patients with high PC transfusion on the intensive care unit (ICU) (area under the curve 0.76, P=0.002). CONCLUSIONS: Near-patient platelet aggregation may allow the identification of patients with enhanced risk of PC transfusion, both pre-operatively and upon arrival on the ICU.

A comparison of Plateletworks and platelet aggregometry for the assessment of aspirin-related platelet dysfunction in cardiac surgical patients.

OBJECTIVE: To compare the assessment of aspirin-related platelet dysfunction using Plateletworks (Helena Laboratories, Beaumont, TX), a new point-of-care platelet function analyzer, with turbidometric platelet aggregometry, in cardiac surgical patients. DESIGN: Prospective observational study. SETTING: University-affiliated teaching hospital. PARTICIPANTS: Fifty consecutive adult patients undergoing elective cardiac surgery for coronary artery bypass grafting or cardiac valve replacement. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Platelet function was assessed by Plateletworks and turbidometric platelet aggregometry before the commencement of anesthesia. Collagen, 10 microg/mL, was used as the agonist for both techniques. The area under the receiver-operator curve for the identification of recent aspirin ingestion (or=72 hours) using Plateletworks was 0.58 (95% confidence interval [CI] 0.42-0.75) versus 0.77 (95% CI 0.61-0.95) for turbidometric platelet aggregometry. The Spearman correlation coefficient (rho) between preoperative Plateletworks trade mark and postoperative mediastinal blood loss was 0.07 (p = 0.58), and between preoperative turbidometric platelet aggregometry and postoperative mediastinal blood loss was -0.31 (p = 0.03). On completion of surgery, the correlation coefficients were 0.14 (p = 0.34) and -0.29 (p = 0.08), respectively. CONCLUSION: These findings suggest that Plateletworks is of limited use for the detection of aspirin-related platelet defects in cardiac surgical patients.