RESUMO
AIM: The study assessed the benefit of high bolus dose tirofiban (HD-tirofiban) with enoxaparin compared with HD-tirofiban with unfractionated heparin (UFH). The study examined markers of platelet activation, thrombin generation and inflammation. MATERIALS AND METHODS: The study is a prospective single centre open-label trial of patients with high-risk acute coronary syndrome treated with percutaneous intervention (PCI) who were randomized to anticoagulation with UFH or enoxaparin with HD-tirofiban (25 microg kg(-1) bolus). This study measured a panel of platelet activation markers, inflammatory biomarkers and thrombus generation between the two groups. RESULT: Sixty patients undergoing high-risk PCI were enroled in the study. Platelet inhibition as assessed by whole blood aggregometry following HD-tirofiban infusion was similar in both the UFH and enoxaparin groups. CD40 ligand expression on platelets was significantly reduced following PCI with HD-tirofiban and either UFH or enoxaparin. Following PCI, there were significant reductions measured in other markers of platelet activation including PAC-1, P selectin, factor V/Va, platelet-monocyte aggregates and monocyte expression of Mac-1 as determined by analysis of venous blood samples using flow cytometry. Prothrombin fragment 1+2, D-dimer, von Willebrand factor and high sensitive C-reactive protein levels were significantly less post PCI in the enoxaparin group compared with those patients receiving UFH. CONCLUSION: The combination of HD tirofiban with enoxaparin resulted in an attenuated inflammatory response when compared with that of the combination of HD tirofiban with UFH.
Assuntos
Síndrome Coronariana Aguda/tratamento farmacológico , Anticoagulantes/farmacologia , Ligante de CD40/metabolismo , Enoxaparina/farmacologia , Heparina/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Tirosina/análogos & derivados , Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/imunologia , Síndrome Coronariana Aguda/terapia , Idoso , Angioplastia com Balão , Biomarcadores/sangue , Fatores de Coagulação Sanguínea/análise , Plaquetas/imunologia , Enoxaparina/administração & dosagem , Feminino , Citometria de Fluxo , Heparina/administração & dosagem , Humanos , Inflamação/imunologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Tirofibana , Tirosina/administração & dosagem , Tirosina/farmacologiaRESUMO
This study investigated fundamental mechanisms that anaerobic biomass employ to cope with salinity, and applied these findings to a continuous SAMBR. When anaerobic biomass was exposed to 20 and 40 g NaCl/L for 96 h, the main solute generated de novo by biomass was trehalose. When we separately introduced trehalose, N-acetyl-ß-lysine and potassium into a batch culture a slight decrease in sodium inhibition was observed. In contrast, the addition of 0.1 mM and 1 mM of glycine betaine dramatically improved the adaptation of anaerobic biomass to 35 g NaCl/L, and it continued to enhance the adaptation of biomass to the salt for the next three batch feedings without further addition. No shift in archaeal microbial diversity was found when anaerobic biomass was exposed in batch mode to 35 g NaCl/L for 360 h, and no changes were found when glycine betaine was added. The dominant species identified under these conditions were Methanosarcina mazeii and Methanosaeta sp. The addition of 5 mM glycine betaine to a continuous SAMBR at 12 h hydraulic retention time (HRT), and operation in batch mode for 2 days can significantly enhance saline (35 g NaCl/L) synthetic sewage degradation. In addition, the injection of 1 mM of glycine betaine into a SAMBR for five subsequent days also significantly enhanced dissolved organic carbon (DOC) removal from sewage under these conditions. The main compatible solutes generated by anaerobic biomass after 44 days exposure to 35 g NaCl/L in a SAMBR were N-acetyl-ß-lysine and glycine betaine. Finally, the addition of 1 mM glycine betaine to the medium was beneficial for anaerobic biomass in batch mode at 20 °C under saline and non saline conditions.
Assuntos
Reatores Biológicos , Resíduos Industriais , Membranas Artificiais , Cloreto de Sódio , Anaerobiose , Biodegradação Ambiental , Methanosarcina/metabolismo , Methanosarcinales/metabolismo , SolubilidadeRESUMO
BACKGROUND: Platelet-monocyte aggregates and other markers of platelet activation were investigated before and after percutaneous coronary intervention (PCI) with abciximab therapy. The study sought to assess the relationship between the level of platelet-monocyte aggregation and increases in cardiac troponin I post coronary intervention. METHODS: Blood samples were collected from 40 patients before PCI and 10 min after abciximab administration. These were tested for platelet activation markers by flow cytometry. Cardiac troponin I levels were assayed at baseline and at 24 h post PCI. RESULTS: Compared to healthy controls, patients with coronary artery disease had elevated markers of platelet activation including platelet-monocyte aggregates, P-selectin and PAC-1 (a marker specific for activated glycoprotein IIb/IIIa) prior to PCI. Increased levels of platelet-monocyte aggregates before PCI were associated with increased expression of P-selectin on the platelet surface. Abciximab therapy reduced platelet-monocyte aggregate levels but had no effect on P-selectin expression. The high levels of expression of activated glycoprotein IIb/IIIa (PAC-1) on platelets prior to PCI was reduced with abciximab therapy. Patients with higher levels of platelet-monocyte aggregates prior to PCI were more likely to develop an elevation of cardiac troponin I during the 24 h after PCI. CONCLUSIONS: Increased levels of platelet-monocyte aggregates may predict patients at risk for troponin elevation following PCI and identify those most likely to benefit from abciximab.
Assuntos
Doença da Artéria Coronariana/sangue , Monócitos/fisiologia , Selectina-P/sangue , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Troponina I/sangue , Abciximab , Adulto , Idoso , Angioplastia Coronária com Balão , Anticorpos Monoclonais/farmacologia , Estudos de Casos e Controles , Agregação Celular/efeitos dos fármacos , Doença da Artéria Coronariana/terapia , Feminino , Humanos , Fragmentos Fab das Imunoglobulinas/farmacologia , Masculino , Pessoa de Meia-Idade , Selectina-P/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/efeitos dos fármacos , Troponina I/efeitos dos fármacosRESUMO
This study was designed to detect any effect that different types of coagulation instrument may have on the International Sensitivity Index (ISI) of a thromboplastin. Manufacturers of commercial thromboplastins now calibrate their reagents against the World Health Organization international reference preparation to assign them an ISI. This enables the prothrombin time (PT) estimated with that reagent to be expressed as an International Normalised Ratio (INR). One batch of Thromborel S was calibrated against the Australasian Reference Thromboplastin (ART). The Thromborel S was used on three photo-optical instruments, the Automated Coagulation Laboratory (ACL) (Instrumentation Laboratory), the Cobas Fibro (Roche), and the Coag-a-Pet (General Diagnostics). PTs using ART were performed manually using the reference method. The ISIs calibrated in our laboratory when the ACL and Cobas Fibro were used were not significantly different at the 95% level, being 1.102 +/- 0.018 and 1.134 +/- 0.022 respectively. The ISI with the Coag-a-Pet of 1.223 +/- 0.023 was significantly different to that of the ACL and the Cobas Fibro at the 95% level. The flowcharts for a computer program to perform the necessary calculations are provided. The program allows for the entry and editing of data from the calibration procedure, and provides a mean normal PT and normal range, the ISI and 95% confidence limits of the calibration, and a chart for the conversion of the test PTs to INRs. The authors have made available an IBM compatible program for the calibration of thromboplastins.
Assuntos
Testes de Coagulação Sanguínea/instrumentação , Tromboplastina/normas , Calibragem , Humanos , Cooperação Internacional , Tempo de Protrombina , Padrões de Referência , Reprodutibilidade dos Testes , Design de SoftwareRESUMO
The effectiveness and mechanism of aprotinin reduced bleeding after cardiopulmonary bypass surgery was studied in a double blind randomised study of 106 patients undergoing valve replacement surgery. Aprotinin therapy was associated with significant reduction in perioperative bleeding and postoperative blood transfusion requirements. Although initially tissue plasminogen activator (t-PA) activity was lower in the aprotinin than placebo group, as surgery proceeded this difference was reversed due to less plasminogen activator inhibitor-1 release in the aprotinin group. This indicates that aprotinin-mediated suppression of fibrinolysis as demonstrated by reduced D-dimer concentration was not related to t-PA. Furthermore, similar perioperative reduction of plasminogen levels in aprotinin and placebo groups indicated a similar degree of conversion of plasminogen to plasmin. However, less plasmin bound with alpha 2-antiplasmin in the plasma in the aprotinin group as it was already complexed with aprotinin where it remained protected from the natural inhibitor on the intact fibrin surface. The reduced fibrinolytic activity of the aprotinin group was thus brought about by the complexing of aprotinin with the plasmin which was bound to the fibrin surface.
Assuntos
Aprotinina/uso terapêutico , Perda Sanguínea Cirúrgica/prevenção & controle , Ponte Cardiopulmonar/efeitos adversos , Fibrinolisina/antagonistas & inibidores , Hemorragia Pós-Operatória/prevenção & controle , Inibidores de Serina Proteinase/uso terapêutico , Adulto , Método Duplo-Cego , Ensaio de Imunoadsorção Enzimática , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinólise , Hemodiluição , Humanos , Hemorragia Pós-Operatória/etiologia , Trombina/metabolismo , Ativador de Plasminogênio Tecidual/metabolismoRESUMO
BACKGROUND: In this study we compared the clinical efficiency, safety, and economic benefit of low-dose aprotinin with epsilon aminocaproic acid (EACA) in reducing bleeding after cardiopulmonary bypass operation. METHODS: In a double-blind, randomized study, 100 patients received low-dose aprotinin (2 x 10(6) kallikrein inhibitor units) or EACA (20 g). The surgical procedure was single- or double-valve replacement with or without coronary artery bypass grafts. RESULTS: Mediastinal chest drainage and transfusion requirements with both therapies were similar. There were no urgent reoperations to secure hemostasis in either group. Similar levels of D-dimer with both therapies indicate a similar inhibition of fibrinolysis. Release of troponin I was less in the low-dose aprotinin group 1 and 4 hours after bypass, although electrocardiographic measurements did not reflect this difference. Levels of S-100beta and neuron-specific enolase were similar with both therapies, confirming that there was no difference in the occurrence of any adverse neurologic events in either group. CONCLUSIONS: Low-dose aprotinin and EACA showed similar effects on the reduction of intraoperative and postoperative bleeding. The lower cost of EACA with no change in safety outcome suggests it is the preferred treatment.
Assuntos
Ácido Aminocaproico/uso terapêutico , Antifibrinolíticos/uso terapêutico , Aprotinina/administração & dosagem , Perda Sanguínea Cirúrgica/prevenção & controle , Ponte Cardiopulmonar , Inibidores de Serina Proteinase/administração & dosagem , Ácido Aminocaproico/economia , Antifibrinolíticos/economia , Custos e Análise de Custo , Método Duplo-Cego , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Humanos , Masculino , Complicações Pós-Operatórias/epidemiologia , Estudos Prospectivos , Inibidores de Serina Proteinase/economiaRESUMO
BACKGROUND: Intraoperative antifibrinolytic treatment with aprotinin and epsilon aminocaproic acid (EACA) has been shown to be effective prophylaxis in the reduction of excessive bleeding after cardiopulmonary bypass operations. This study investigated the effectiveness of both drugs when used as a postoperative treatment of patients showing early signs of increased bleeding. METHODS: In a double-blind, randomized study, 69 patients with chest drainage of 100 mL or more 1 hour after bypass were treated with aprotinin, EACA, or placebo. RESULTS: In the first 24 hours postoperatively, neither drug significantly reduced chest drainage or blood transfusion requirements compared with placebo. Median (interquartile) cumulative chest drainage volumes for the first 24 hours postoperatively for the aprotinin, EACA, and placebo groups were 525 (340, 750), 575 (450, 762), and 650 (550, 800) mL, respectively. Among the study patients, 4 undergoing valve operation and treated with aprotinin showed a trend toward less bleeding during the first 12 hours postoperatively compared with 5 valve operation patients who received placebo (p = 0.06). Among all patients, the treatment with aprotinin or EACA failed to reduce levels of D-dimer compared with placebo after treatment, indicating that fibrinolysis was not significantly inhibited. CONCLUSIONS: Aprotinin or EACA administered in the early postoperative period was ineffective in reducing postoperative bleeding with the exception of a small group of patients having valve operations in whom aprotinin treatment may have shown some benefit.
Assuntos
Ácido Aminocaproico/administração & dosagem , Aprotinina/administração & dosagem , Ponte Cardiopulmonar , Doença das Coronárias/cirurgia , Doenças das Valvas Cardíacas/cirurgia , Hemorragia Pós-Operatória/tratamento farmacológico , Idoso , Ácido Aminocaproico/efeitos adversos , Aprotinina/efeitos adversos , Ponte de Artéria Coronária , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Implante de Prótese de Valva Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios , Falha de TratamentoRESUMO
BACKGROUND: Aprotinin therapy is now widely used during cardiac surgery. This study examined the clinical and economic effectiveness of high-dose or low-dose aprotinin in comparison to placebo. METHODS: In a double blind, randomized study, three groups of 50 patients received high-dose aprotinin costing AUS$614 per patient (AUS$ = Australian dollars), low-dose aprotinin costing AUS$220 per patient or placebo. Resource use influenced by aprotinin therapy was measured. RESULTS: Both doses were effective in reducing chest drainage and postoperative transfusion requirements, high-dose being more effective than low-dose. Both doses reduced the rate of reoperations for hemostasis. A base case of statistically significant differences associated with the high-dose and low-dose aprotinin showed cost savings of AUS$77 and AUS$348 per patient, respectively. If the demonstrated less significant reductions in operating room and ward stay are included, these savings become AUS$463 and AUS$715, respectively. Alternately, if cross-matches are replaced by group-and-hold and cell savers are not used, the savings per patient would be AUS$196 and AUS$467, respectively. CONCLUSIONS: While high-dose aprotinin is clinically more effective than low-dose aprotinin, low-dose therapy demonstrates greater cost savings.
Assuntos
Aprotinina/administração & dosagem , Ponte Cardiopulmonar , Hemostáticos/administração & dosagem , Aprotinina/efeitos adversos , Aprotinina/economia , Austrália , Perda Sanguínea Cirúrgica , Transfusão de Sangue , Ponte Cardiopulmonar/economia , Análise Custo-Benefício , Método Duplo-Cego , Valvas Cardíacas/cirurgia , Hemostáticos/efeitos adversos , Hemostáticos/economia , HumanosRESUMO
Excessive bleeding after cardiopulmonary bypass operations is a persistent problem. This study assessed the influence of platelet function on blood loss for 134 patients undergoing cardiopulmonary bypass. Platelet function was measured by platelet aggregation in platelet-rich plasma and whole blood using collagen as the agonist. Adenosine triphosphate release was assessed concurrently. Measurements were made 1 day before operation and 1 hour after the cessation of cardiopulmonary bypass. Three important findings were made. First, statistically significant correlations were shown between preoperative and postoperative platelet aggregation and blood drainage for the first 3 hours postoperatively. Second, correlations were greatest when preoperative measurement was performed on whole blood and postoperative measurement was performed on platelet-rich plasma. Third, patients with reduced postoperative platelet aggregation in platelet-rich plasma had significantly greater transfusion requirements in the first 24 hours postoperatively. In defining the 16 patients who bled excessively among the 134 patients studied, the preoperative aggregation in whole blood had a sensitivity of 62%, specificity of 75%, positive predictive value of 26%, and negative predictive value of 94%. The postoperative aggregation in platelet-rich plasma had a sensitivity of 86%, specificity of 69%, positive predictive value of 28%, and negative predictive value of 97%. These results indicate that preoperative and postoperative measurement of platelet aggregation may provide a rationale for the prophylaxis or treatment of patients to reduce blood loss after cardiopulmonary bypass.
Assuntos
Perda Sanguínea Cirúrgica , Ponte Cardiopulmonar/efeitos adversos , Hemorragia/sangue , Agregação Plaquetária , Trifosfato de Adenosina/metabolismo , Transfusão de Sangue/estatística & dados numéricos , Volume Sanguíneo , Colágeno , Drenagem , Estudos de Avaliação como Assunto , Hemorragia/etiologia , Hemorragia/terapia , Humanos , Plasma , Testes de Função Plaquetária/métodos , Cuidados Pós-Operatórios , Cuidados Pré-Operatórios , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: This study was designed to determine the benefit of aprotinin therapy in reducing bleeding during and after cardiopulmonary bypass in patients with preoperative platelet dysfunction. Platelet function involvement in the mechanism by which aprotinin acts was also investigated. METHODS: In a double-blind, randomized study, patients received high-dose aprotinin (n = 54) or placebo (n = 52). Whole blood aggregation was measured preoperatively. Platelet function and activation in both groups were assessed intraoperatively and postoperatively at five times. RESULTS: Aprotinin significantly reduced perioperative bleeding and postoperative blood transfusion. Placebo-treated patients with reduced preoperative platelet aggregation bled more postoperatively, but aprotinin reduced the bleeding in patients with normal or reduced platelet function to similar levels. Any cardiopulmonary bypass-induced changes in platelet aggregation, platelet activation as measured by P-selectin expression, and von Willebrand factor antigen and function were similar in aprotinin-treated and placebo-treated groups. CONCLUSIONS: The mechanism by which aprotinin reduced bleeding was independent of any effect on platelet function. However, aprotinin produced a greater reduction in bleeding among patients whose condition was hemostatically compromised by preoperative platelet dysfunction.
Assuntos
Aprotinina/uso terapêutico , Perda Sanguínea Cirúrgica/prevenção & controle , Plaquetas/fisiologia , Ponte Cardiopulmonar , Inibidores de Serina Proteinase/uso terapêutico , Transfusão de Sangue , Método Duplo-Cego , Feminino , Citometria de Fluxo , Próteses Valvulares Cardíacas , Humanos , Masculino , Pessoa de Meia-Idade , Ativação Plaquetária/fisiologia , Agregação Plaquetária/fisiologia , Testes de Função Plaquetária , Fator de von Willebrand/metabolismoRESUMO
The Australasian Reference Thromboplastin (ART) is now produced in a low turbidity form (ART-LT) for use in photo-electrical coagulometers. This study was designed to assess the suitability of ART and ART-LT for use on a fully automated centrifugal analyser, the ACL300 Research (ACL). These reagents were compared to Thromborel S (TRL), the reagent currently in successful use in our laboratory. It was found that regular ART was an unsuitable reagent for the ACL due to poor daily quality control testing (QC) precision at an INR of 4.5. The ACL also had the effect of significantly altering the ISI of ART from its recommended value as determined for manual testing. ART-LT was found to be an acceptable reagent on the ACL even though its QC precision was lower than that of TRL. The reagent was stable throughout its 8 wk shelf-life. The ACL significantly altered the ISI (International Sensitivity Index) of ART-LT. This may no longer be a disadvantage, as ART-LT is now provided with an ISI specifically for its use on the ACL.
Assuntos
Testes de Coagulação Sanguínea/métodos , Tromboplastina , Testes de Coagulação Sanguínea/instrumentação , Humanos , Controle de Qualidade , Padrões de Referência , Tromboplastina/normasRESUMO
This double-blind, randomized study compared the mechanisms by which low-dose aprotinin and epsilon-aminocaproic acid (EACA) inhibited fibrinolysis during cardiopulmonary bypass surgery. D-dimer levels during and after bypass were similar, indicating an equivalent inhibition of fibrinolysis. Effects on tissue plasminogen activator release were not associated with the inhibition of fibrinolysis by either drug. Treatment with EACA was associated with a substantial release of endogenous alpha2-antiplasmin, particularly 1 h after bypass. Compared with the aprotinin group, higher levels of the plasmin-alpha2-antiplasmin complex in the EACA group confirmed an increased inhibition of plasmin by alpha2-antiplasmin. In conclusion, it is hypothesized that EACA inhibited fibrinolysis by stimulating the release of the patients' own alpha2-antiplasmin.
Assuntos
Ácido Aminocaproico/administração & dosagem , Antifibrinolíticos/administração & dosagem , Ponte Cardiopulmonar , alfa 2-Antiplasmina/metabolismo , Aprotinina/administração & dosagem , Método Duplo-Cego , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinólise/efeitos dos fármacos , Doenças das Valvas Cardíacas/cirurgia , Hemostáticos/administração & dosagem , Humanos , Ativador de Plasminogênio Tecidual/metabolismoRESUMO
In order to study the effects of cardiopulmonary bypass (CPB) on fibrinolysis and platelet function and the possible relationship of these effects on post-operative blood loss, 127 patients undergoing CPB were examined. There was a significant reduction in the median levels of fibrinogen, plasminogen, alpha 2-antiplasmin, fibrinolytic potential and platelet aggregation during CPB (P < or = 0.001). Median levels of soluble fibrin, fibrinogen degradation products, D-dimer and PAI-1 were increased, while the level of t-PA activity remained constant. Post-CPB levels of fibrinogen and plasminogen correlated negatively with blood loss (P = 0.003 and P < 0.001, respectively) and interestingly, lower levels of alpha 2-antiplasmin and higher levels of t-PA activity before CPB were associated with greater blood loss after CPB (P < 0.001 and P = 0.004, respectively). Better pre-CPB platelet function correlated with lower levels of D-dimer before and after CPB. As expected, haemodilution had a significant effect on fibrinolytic and coagulation parameters post-CPB; the greater the haemodilution, the more the concentration of fibrinogen, plasminogen and alpha 2-antiplasmin fell post-CPB and the greater the blood loss. The increase in PAI-1 levels intra-CPB appeared to result in mean t-PA activity remaining unchanged 1 h post-CPB. Post-CPB increases in soluble fibrin were paralleled by increases in fibrinogen degradation products and D-dimer, suggesting that intra-operative contact activation is related to activation of the fibrinolytic system. The present findings indicate the greater the fibrinolytic activation, the greater the post-CPB blood loss.
Assuntos
Plaquetas/fisiologia , Ponte Cardiopulmonar , Fibrinólise , Hemorragia/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Ponte Cardiopulmonar/efeitos adversos , Feminino , Fibrina/metabolismo , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinogênio/metabolismo , Hemodiluição , Hemorragia/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Plasminogênio/metabolismo , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Agregação Plaquetária , Ativador de Plasminogênio Tecidual/metabolismo , alfa 2-Antiplasmina/metabolismoRESUMO
Excessive perioperative and postoperative bleeding continue to complicate cardiopulmonary bypass surgery (CPB). In this study we measured the von Willebrand factor antigen (vWF:Ag), collagen binding assay (CBA) and ristocetin cofactor assay (RiCo) in 52 patients undergoing CPB. The collagen binding assay employs the affinity of the high-molecular-weight multimers of vWF to collagen and was used in this study to demonstrate differences in the multimeric composition of vWF during and after CPB. The observed values for the vWF:Ag, CBA and RiCo were correlated to the amount of postoperative bleeding. Both the preoperative vWF:Ag and the CBA showed significant negative correlation with postoperative blood loss (r = -0.3046, P < 0.05 and r = -0.3228, P < 0.05 respectively). Higher blood loss figures correlated with lower vWF:Ag, CBA and RiCo during and after surgery with the strongest correlation 1 h post-op between both vWF:Ag and CBA and actual blood loss (r = -0.5061, P < 0.001 and r = -0.4942, P < 0.001 respectively). The strong negative correlations between vWF:Ag, CBA and RiCo before, during and after CPB and blood loss data verify the important role of vWF in primary haemostasis. Of particular note, the negative correlations between preoperative levels of vWF:Ag, CBA and postoperative blood loss provide valuable insight into another possible mechanism of excessive bleeding post CPB.
Assuntos
Perda Sanguínea Cirúrgica , Ponte Cardiopulmonar/efeitos adversos , Fator de von Willebrand/fisiologia , Sistema ABO de Grupos Sanguíneos , Envelhecimento , Antígenos/análise , Tempo de Sangramento , Colágeno/metabolismo , Feminino , Hemodiluição , Humanos , Masculino , Complicações Pós-Operatórias , Caracteres Sexuais , Fator de von Willebrand/análiseRESUMO
Differences in the activated partial thromboplastin time (aPTT) were shown when blood taken from patients receiving intravenous heparin therapy was collected into 5 ml and 1 ml citrate containers. Mean aPTTs were 27% shorter with the plasma from the 1 ml citrate containers (n = 23). These results were paralleled by a 37% reduction in the mean heparin concentration (n = 11) and a 77% increase in the mean platelet factor 4 (PF4) concentration (n = 7). This phenomenon is due to increased platelet activation and subsequent increased heparin neutralization in the 1 ml citrate container. In an attempt to overcome this, the citrate was removed from a 1 ml container and replaced with a buffered tri-sodium citrate solution containing theophylline, adenosine and dipyridamole anticoagulant (CTAD). Blood from heparinized patients taken into both 5 ml citrate and 1 ml CTAD showed a correction of the shortening artefact in the low volume container. The mean aPTT of plasmas from the 1 ml CTAD container showed an increase of 10% compared with the 5 ml citrate. There was no significant difference in the mean heparin or PF4 concentrations of blood taken into either container. The 1 ml CTAD tube described is a suitable collection container for monitoring heparin in neonates or patients who are difficult to venepuncture and overcomes the neutralization of heparin in part filled low volume containers.
Assuntos
Coleta de Amostras Sanguíneas/instrumentação , Heparina/uso terapêutico , Tempo de Tromboplastina Parcial , Citratos , Ácido Cítrico , Heparina/sangue , Humanos , Fator Plaquetário 4/análiseRESUMO
The concentrated thrombin time (CTT), a thrombin time performed with a high concentration of thrombin, was evaluated as an alternative to the activated partial thromboplastin time (APTT) for monitoring of heparin therapy. Forty-nine plasmas from patients receiving unfractionated heparin therapy were tested. It was first demonstrated that CTTs using three commercial reagents could be standardised against CTTs performed with a reference reagent, MRC reagent 66/305. For comparison, APTTs were performed on the plasmas. As a benchmark of the degree of heparinisation, the heparin concentration of the plasmas was determined by chromogenic anti-IIa heparin assays, therapeutic range being 0.2-0.4 units/ml. The optimal relationships of the CTTs and APTT with the heparin concentration were established. These were used to predict the heparin concentrations of the plasmas from the results of the APTT, CTT performed with the reference reagent, and transformed CTT performed with each of the three commercial reagents. In predicting the assayed plasma heparin concentrations, the accuracy of the APTT was only 53%, while the CTT was from 78 to 82%. The CTT can be standardised and, subject to results of clinical trials, could provide an improved method of monitoring heparin therapy.
Assuntos
Testes de Coagulação Sanguínea/normas , Coagulação Sanguínea/efeitos dos fármacos , Heparina/farmacologia , Afibrinogenemia/sangue , Artefatos , Heparina/administração & dosagem , Heparina/sangue , Heparina/uso terapêutico , Humanos , Indicadores e Reagentes , Tempo de Tromboplastina Parcial , Padrões de ReferênciaRESUMO
This prospective study was designed to test the hypothesis that intraoperative hypothermia occurring during abdominal aortic surgery and vasodilator therapy used to avoid severe consequences of aortic clamping could both disturb the mixed venous oxygen saturation signal (SVO2). Twenty high risk surgical patients, ASA physical status II or III, were catheterized with the standard pulmonary artery catheter; SVO2 was determined by direct spectrophotometric measurements of oxygen haemoglobin concentration of serial samples. The relationships between SVO2, haemodynamic, metabolic variables and core temperature were analyzed. Haemodynamic values and oxygen transport were stable while inadequate tissue oxygenation occurred. A significant correlation was found between SVO2 and CI (r = 0.59, p less than 0.01), SVO2 and SVRI (r = -0.4, p less than 0.01), SVO2 and CT (r = -0.46, p less than 0.01), SVO2 and VO2 (r = -0.76, p less than 0.001). SVO2 and Qs/Qt (r = 0.83, p less than 0.001), SVO2 and EO2 (r = -0.75, p less than 0.001. No correlation was observed between SVO2 and lactacidemia (r = 0.04, p less than 0.05). Satisfactory haemodynamic stability and oxygen transport steady-state were the main conditions for a significant correlation between SVO2 and haemodynamic factors. However, there was no correlation between SVO2 and inadequate tissue oxygenation. SVO2 reflected only oxygen extraction. Intraoperative hypothermia provided an increased haemoglobin affinity for oxygen. Vasodilator therapy which allowed a decrease in systemic vascular resistance produced an increase in the left-right shunt and in venous oxygen admission. Thus hypothermia and vasodilator therapy could be both responsible for the elevated SVO2 occurring during infrarenal abdominal aortic surgery.
Assuntos
Aorta Abdominal/cirurgia , Hipotermia Induzida , Oxigênio/sangue , Vasodilatadores/uso terapêutico , Feminino , Hemodinâmica , Humanos , Masculino , Monitorização Fisiológica , Consumo de Oxigênio , Estudos ProspectivosRESUMO
The purpose of this work was to study the hemodynamic effects of a pituitary extract (Post-Hypophyse, Choay, EPH) and of lysine vasopressin (Diapid, Sandoz, VP). Cardiac, pulmonary and liver hemodynamics were measured in 50 cirrhotic patients before and during intravenous infusion (0.45 IU/kg/h) of EPH (24 patients) or VP (26 patients). EPH and VP did not have identical consequences in cardiac output and systemic resistances. EPH significantly increased cardiac output and significantly decreased systemic resistances while VP significantly and increased systemic resistances. Both vasoactive drugs similarly decreased myocardial performances. EPH and VP had a moderate influence on WHV/IVC pressure gradient. This was variable from one patient to another. The decrease of WHV/IVC pressure gradient observed during EPH infusion was mainly related to an increase of IVC pressure. Since the effects of both drugs on WHV/IVC pressure gradient are slight and unpredictable and they exert an important effect on cardiopulmonary hemodynamics, caution should be taken in administering EPH or VP to cirrhotic patients. The clinical use of EPH or VP should be undertaken only when cardiac and liver hemodynamics monitoring are available.
Assuntos
Hemodinâmica/efeitos dos fármacos , Circulação Hepática/efeitos dos fármacos , Cirrose Hepática/fisiopatologia , Lipressina/farmacologia , Hormônios Neuro-Hipofisários/farmacologia , Sistema Porta/fisiopatologia , Extratos de Tecidos/farmacologia , Débito Cardíaco/efeitos dos fármacos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacosRESUMO
We studied the relationship between pregnancy and pancreatitis together with reviewing the bibliography after having had 4 cases. As far as the aetiology is concerned there does not seem to be a mechanical factor associated with the pregnant uterus but a vesicular factor (gall bladder) of stasis and hypersecretion, with hyperlipidaemia of pregnancy and pancreatic oversecretion in pregnancy, all of which are finally associated with a neuro-vegetative lack of tone and with the part played by certain drugs that are often prescribed in pregnancy. The fetal prognosis is relatively good except for the risks of premature delivery. Management of a case of acute severe pancreatitis is difficult to work out. All the same, the treatment should be above all conservative, which means medical. Surgery should be reserved for those cases with definite indications such as progressive deterioration in spite of medical treatment with the knowledge beforehand that it will not make much difference to the final prognosis.
Assuntos
Pancreatite , Complicações na Gravidez , Adolescente , Adulto , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Feminino , Humanos , Pancreatite/induzido quimicamente , Pancreatite/etiologia , Pancreatite/terapia , Gravidez , Complicações na Gravidez/induzido quimicamente , Complicações na Gravidez/etiologia , Complicações na Gravidez/terapiaRESUMO
The case of a 31 year old woman with staphylococcal toxic shock syndrome is reported. The usual clinical characteristics were found: it began during a menstrual period, and she presented with a state of shock, a high fever and a cutaneous eruption. Its evolution was marked by pulmonary interstitial oedema and acute renal failure requiring dialysis; the patient recovered but residual renal failure was still present four months later. A Staphylococcus aureus was isolated from vaginal, nasal and tracheal cultures. It produced enterotoxins A and F, which were responsible for the symptoms.