RESUMO
Acute normovolemic hemodilution (ANH) is a potential transfusion method for platelets, as well as for red blood cells. However, previous studies have shown that whole blood storage in ANH decreases platelet aggregability by 14.7-76.3% and that this decrease is not recovered by reinfusion. We investigated whether a new whole blood storage method for 6 h using a polyolefin bag, based on the platelet concentrates storage method, would maintain platelet function better than the conventional method using a polyvinyl chloride bag. We demonstrated that storage of whole blood in a polyolefin bag maintained ADP-induced aggregation rates at more than twofold higher than those in a polyvinyl chloride bag, and also significantly suppressed P-selectin expression, a platelet activation marker (ADP-induced aggregation rates: 24.6 ± 5.1% vs. 51.7 ± 11.5%, p = 0.002; P-selectin expression; 50.3 ± 8.4MFI vs. 31.6 ± 9.3MFI, p = 0.018). These results could be attributed to the high gas permeability of polyolefin, which lowered PCO2 and maintained a high pH with or without agitation. There were no significant changes in platelet count and red blood cell parameters due to the storage methods. Our results suggest that ANH using polyolefin bags is advantageous in improving hemostatic function compared to the conventional method.
Assuntos
Plaquetas/fisiologia , Preservação de Sangue/instrumentação , Preservação de Sangue/métodos , Determinação do Volume Sanguíneo/métodos , Hemodiluição/métodos , Hemostasia , Polienos/química , Hemodiluição/estatística & dados numéricos , Humanos , Ativação Plaquetária , Agregação Plaquetária , Testes de Função PlaquetáriaRESUMO
BACKGROUND: The majority of allogeneic transfusions occur in the perioperative setting, especially during cardiac surgery. In addition to the economic implications, there is emerging evidence that blood transfusion may increase both morbidity and mortality. Acute normovolemic hemodilution (ANH) may limit the need for blood products. OBJECTIVES: The primary objective of this study was to determine if the method of blood collection (syringe or bag) during the ANH process impacted the platelet count and function. The secondary objectives included the need for perioperative blood transfusions during the procedure and in the intensive care unit. In addition, we assessed these outcomes' associations with ANH parameters including the method of collection, time of storage, and volume removed. METHODS: Data were collected prospectively from 50 patients undergoing cardiac surgery on cardiopulmonary bypass over a 6-month period. Platelet count and function were measured for the ANH blood immediately after collection and again prior to transfusing to the patient at the end of cardiopulmonary bypass. Other data collected included ANH volume, length of storage, and the quantity of all blood products given throughout the perioperative period. RESULTS: No change in platelet count or function was noted regardless of the length of time or collection method for the ANH blood. Twenty-three patients received blood or blood products in the operating room or the intensive care unit, while 27 patients received no blood transfusion during their entire hospitalization. Higher ANH volume (ml·kg-1 ) and longer storage time were associated with a greater need for intraoperative transfusions. CONCLUSION: Acute normovolemic hemodilution protects the platelets from the untoward effects of cardiopulmonary bypass and offers an important autologous blood product that improves hemostasis at the conclusion of surgery. Platelet count and function are preserved regardless of the method of collection or the length of storage. The volume of ANH removed appears to be an important determinant of blood product use and further understanding of the impact of this variable is a future direction of upcoming prospective research.
Assuntos
Transfusão de Sangue/estatística & dados numéricos , Hemodiluição/estatística & dados numéricos , Cuidados Intraoperatórios/estatística & dados numéricos , Adolescente , Adulto , Procedimentos Cirúrgicos Cardíacos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Prospectivos , Adulto JovemRESUMO
Patients needing the assistance of extracorporeal membrane oxygenation (ECMO) are at risk of hemodilution and, in some instances, may require exposure to large amounts of allogeneic blood products. Patient outcomes can be improved by taking steps to reduce transfusions and hemodilution. Currently, modified ultrafiltration (MUF) is used across the world to reduce hemodilution after cardiopulmonary bypass (CPB). Another common technique during bypass initiation is autologous priming. By applying modified versions of these techniques, ECMO patients may potentially benefit. Usually, patients requiring immediate transition from CPB to ECMO are not stable enough to tolerate MUF. Through alterations of the CPB and ECMO circuit tubing, MUF can be performed once on ECMO. Another technique to potentially lower the transfusion requirements for ECMO patients is a complete circuit blood transfer during an ECMO circuit exchange. While selective component changes are preferred if possible, occasionally a complete circuit change must be done. To minimize hemodilution or prevent priming with blood products, the original ECMO circuit's blood can be transferred to the new ECMO circuit before connecting to the patient. Both of these techniques, in our opinion, helped to reduce the number of transfusions that our ECMO patients have seen during these critical time periods.
Assuntos
Transfusão de Sangue , Oxigenação por Membrana Extracorpórea/métodos , Hemodiluição , Hemofiltração , Transfusão de Sangue/estatística & dados numéricos , Ponte Cardiopulmonar/métodos , Desenho de Equipamento , Oxigenação por Membrana Extracorpórea/efeitos adversos , Oxigenação por Membrana Extracorpórea/instrumentação , Hemodiluição/estatística & dados numéricos , Hemofiltração/instrumentação , Hemofiltração/métodos , Humanos , Ultrafiltração/instrumentação , Ultrafiltração/métodos , Dispositivos de Acesso VascularAssuntos
Ponte Cardiopulmonar/efeitos adversos , Hemodiluição/estatística & dados numéricos , Complicações Intraoperatórias/prevenção & controle , Volume Sanguíneo/efeitos dos fármacos , Volume Sanguíneo/fisiologia , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Hematócrito/métodos , Hemodiluição/métodos , Heparina/administração & dosagem , Humanos , Complicações Intraoperatórias/etiologiaRESUMO
BACKGROUND: An episode of postoperative phenytoin toxicity in a patient undergoing surgery related to craniosynostosis highlighted the presence of hypoalbuminemia. We believe that hypoalbuminemia contributed to the altered pharmacokinetics of phenytoin in this case. OBJECTIVES: To establish the incidence of postoperative hypoalbuminemia in patients undergoing surgery related to craniosynostosis and to investigate the likely etiology. METHODS: Data on 114 patients undergoing surgery for craniosynostosis over a 2-year period at Oxford Children's Hospital, between May 2011 and May 2013, were retrospectively reviewed. Twenty-two patients were excluded due to incomplete data. This cohort represents the entire population for whom transfusion data had been formally collected at our institution. Preoperative and day 1 postoperative serum albumin levels were collected from the hospital laboratory database. Data regarding blood loss and intra-operative fluid management were reviewed from the anesthetic database. Linear regression analysis was used to establish the relationship between percentage drop in serum albumin with: (i) milliliters per kilogram (ml·kg(-1)) volume of albumin-poor fluids used intra-operatively and (ii) percentage estimated red cell mass loss. RESULTS: All patients experienced a statistically significant drop in serum albumin. The mean difference in albumin was 17.1 g·l(-1), 95% CI (16.1-18.0) (P < 0.001). Expressed as a percentage, the mean reduction was 37.9% (range 16-61%), SD 9.7. The decrease in albumin was associated with an increase in estimated red cell mass loss (P < 0.001) and an increased ml·kg(-1) volume of albumin-poor fluids given (P < 0.001). CONCLUSION: Hemodilution due to large volume blood loss and transfusion with albumin-poor fluids is strongly associated with postoperative hypoalbuminemia in patients undergoing surgery related to craniosynostosis. Practitioners should be aware of this risk and the implications of postoperative hypoalbuminemia in this population.
Assuntos
Craniossinostoses , Hipoalbuminemia/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Causalidade , Feminino , Hidratação/estatística & dados numéricos , Hemodiluição/estatística & dados numéricos , Humanos , Incidência , Lactente , Período Intraoperatório , Masculino , Estudos Retrospectivos , Fatores de RiscoRESUMO
BACKGROUND: Infusion of 5% human albumin (HA) and 6% hydroxyethyl starch 130/0.4 (HES) during cardiac surgery expand circulating volume to a greater extent than crystalloids and would be suitable for a restrictive fluid therapy regimen. However, HA and HES may affect blood coagulation and could contribute to increased transfusion requirements. METHODS: We randomly assigned 240 patients undergoing elective cardiac surgery to receive up to 50 ml kg(-1) day(-1) of either HA, HES, or Ringer's lactate (RL) as the main infusion fluid perioperatively. Study solutions were supplied in identical bottles dressed in opaque covers. The primary outcome was chest tube drainage over 24 h. Blood transfusions, thromboelastometry variables, perioperative fluid balance, renal function, mortality, intensive care unit, and hospital stay were also assessed. RESULTS: The median cumulative blood loss was not different between the groups (HA: 835, HES: 700, and RL: 670 ml). However, 35% of RL patients required blood products, compared with 62% (HA) and 64% (HES group; P=0.0003). Significantly, more study solution had to be administered in the RL group compared with the colloid groups. Total perioperative fluid balance was least positive in the HA group [6.2 (2.5) litre] compared with the HES [7.4 (3.0) litre] and RL [8.3 (2.8) litre] groups (P<0.0001). Both colloids affected clot formation and clot strength and caused slight increases in serum creatinine. CONCLUSIONS: Despite equal blood loss from chest drains, both colloids interfered with blood coagulation and produced greater haemodilution, which was associated with more transfusion of blood products compared with crystalloid use only.
Assuntos
Albuminas/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Procedimentos Cirúrgicos Cardíacos , Derivados de Hidroxietil Amido/farmacologia , Soluções Isotônicas/farmacologia , Hemorragia Pós-Operatória/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Testes de Coagulação Sanguínea/métodos , Testes de Coagulação Sanguínea/estatística & dados numéricos , Transfusão de Sangue/estatística & dados numéricos , Procedimentos Cirúrgicos Eletivos/métodos , Feminino , Hidratação/métodos , Hemodiluição/métodos , Hemodiluição/estatística & dados numéricos , Hemostasia/efeitos dos fármacos , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Substitutos do Plasma/farmacologia , Lactato de Ringer , Adulto JovemRESUMO
BACKGROUND: We aimed to examine current practice of the management and secondary prevention of intracerebral haemorrhage (ICH) in China where the disease is more common than in Western populations. METHODS: Data on baseline characteristics, management in-hospital and post-stroke, and outcome of ICH patients are from the ChinaQUEST (QUality Evaluation of Stroke Care and Treatment) study, a multi-centre, prospective, 62 hospital registry in China during 2006-07. RESULTS: Nearly all ICH patients (n = 1572) received an intravenous haemodiluting agent such as mannitol (96%) or a neuroprotectant (72%), and there was high use of intravenous traditional Chinese medicine (TCM) (42%). Neurosurgery was undertaken in 137 (9%) patients; being overweight, having a low Glasgow Coma Scale (GCS) score on admission, and Total Anterior Circulation Syndrome (TACS) clinical pattern on admission, were the only baseline factors associated with this intervention in multivariate analyses. Neurosurgery was associated with nearly three times higher risk of death/disability at 3 months post-stroke (odd ratio [OR] 2.60, p < 0.001). Continuation of antihypertensives in-hospital and at 3 and 12 months post-stroke was reported in 732/935 (78%), 775/935 (83%), and 752/935 (80%) living patients with hypertension, respectively. CONCLUSIONS: The management of ICH in China is characterised by high rates of use of intravenous haemodiluting agents, neuroprotectants, and TCM, and of antihypertensives for secondary prevention. The controversial efficacy of these therapies, coupled with the current lack of treatments of proven benefit, is a call for action for more outcomes based research in ICH.
Assuntos
Hemorragia Cerebral/tratamento farmacológico , Hemorragia Cerebral/cirurgia , Hipertensão/prevenção & controle , Sistema de Registros/estatística & dados numéricos , Anti-Hipertensivos/uso terapêutico , China , Feminino , Hemodiluição/estatística & dados numéricos , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Pacientes Internados/estatística & dados numéricos , Masculino , Manitol , Medicina Tradicional Chinesa/estatística & dados numéricos , Pessoa de Meia-Idade , Fármacos Neuroprotetores/uso terapêutico , Procedimentos Neurocirúrgicos/estatística & dados numéricos , Fatores de Risco , Prevenção Secundária/métodosAssuntos
Transfusão de Sangue/estatística & dados numéricos , Hepatectomia/estatística & dados numéricos , Neoplasias dos Ductos Biliares/cirurgia , Ductos Biliares Intra-Hepáticos , Transfusão de Sangue Autóloga/estatística & dados numéricos , Carcinoma Hepatocelular/cirurgia , Colangiocarcinoma/cirurgia , Técnicas de Apoio para a Decisão , Hemodiluição/estatística & dados numéricos , Hemoglobinometria , Humanos , Coeficiente Internacional Normatizado , Cirrose Hepática/cirurgia , Neoplasias Hepáticas/cirurgia , Contagem de Plaquetas , Cuidados Pré-Operatórios , Probabilidade , Tempo de Protrombina , Reoperação/estatística & dados numéricos , Medição de Risco/estatística & dados numéricos , Fatores de RiscoRESUMO
There continues to be evidence regarding the negative impact of blood transfusion on morbidity and mortality in the adult literature, including infection risk, increased hospital and intensive care length of stay, and costs. More effort has been put into reducing the use of blood components in adult surgical centers but blood transfusions continue to be used frequently in pediatric centers. From 2002 through 2005, we embarked on a mission of reduced prime volume in an effort toward bloodless cardiac surgery to meet the needs of the Jehovah's Witness patient. The same bloodless surgical and perfusion techniques were applied to all patients undergoing cardiopulmonary bypass beginning in 2006. Circuit size was minimized and acute normovolemic hemodilution (ANH) was considered and attempted more often, especially if a re-operation. Retrograde arterial prime (RAP) and venous antegrade prime (VAP), dilutional or balanced ultrafiltration during cardiopulmonary bypass, modified arteriovenous ultrafiltration post bypass, and cell salvage of remaining circuit contents after flushing with crystalloid were recorded. ANH, RAP, and VAP, separately or in combination, were used less than 1% of the time prior to 2006. From 2006-2008 ANH was performed on 42% of the patients and RAP/ VAP was performed on 70% of the patients. From 2006-2008, 43% (287 of 662) of the open heart surgeries were performed bloodless in the operating room versus 30% (193 of 633) from 2003-2005. Bloodless surgery more than doubled for the 0-6, 6-15, and 15-20 kg groups from 3.5%, 23%, and 23% respectively in 2003-2005 to 9%, 44%, and 58%, respectively in 2006-2008. With the cooperation of the entire cardiac surgical team, bloodless open heart surgery is achievable in a pediatric cardiac surgical center, including neonates.
Assuntos
Ponte Cardiopulmonar/métodos , Ponte Cardiopulmonar/estatística & dados numéricos , Hemodiluição/estatística & dados numéricos , Hemofiltração/estatística & dados numéricos , Criança , Pré-Escolar , Feminino , Humanos , Recém-Nascido , Masculino , Ohio/epidemiologia , Estudos Retrospectivos , Resultado do TratamentoAssuntos
Ponte Cardiopulmonar/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Reação Transfusional , Transfusão de Sangue/estatística & dados numéricos , Ponte Cardiopulmonar/efeitos adversos , Ponte de Artéria Coronária/efeitos adversos , Ponte de Artéria Coronária/métodos , Hemodiluição/efeitos adversos , Hemodiluição/estatística & dados numéricos , Humanos , Medição de Risco , Sensibilidade e EspecificidadeRESUMO
PURPOSE: The practice of blood conservation is aimed at improving patient outcomes by avoiding allogeneic transfusions via a coordinated multidisciplinary, multipronged approach. The numerous blood conservation techniques and transfusion alternatives now available are described. SUMMARY: Ongoing concerns exist regarding the availability of the nation's and the world's blood supply. In addition, the number of measures required to ensure blood safety has led to increases in the price of blood and blood products over the past 10-15 years. Moreover, blood transfusion carries inherent risks even under the most favorable circumstances. Investigations have established that injudicious transfusion is associated with development of ventilator-associated pneumonia, nosocomial infection, and organ dysfunction. Because most single blood-conservation techniques reduce blood usage by a mere 1-2 units, a series of integrated conservation approaches are required. These include preoperative autologous donation, use of erythropoietic agents, blood conservation techniques such as acute normovolemic hemodilution, individualized assessment of anemia tolerance, implementation of conservative transfusion thresholds, meticulous surgical techniques, and judicious use of phlebotomy and pharmacologic agents for limiting blood loss. Erythropoietic agents such as epoetin alfa have been used successfully to increase hemoglobin and decrease transfusion requirements, and are appropriate when used in advance of elective surgical procedures. Acquisition costs of erythropoietic stimulating agents versus costs of blood justify economic evaluation by hospitals to make the most cost-effective choice under current economic constraints. CONCLUSION: Initiating a blood management program requires planning and support from those who are concerned about blood usage reduction and outcomes improvement. Launching a vigorous and ongoing educational program to raise awareness about the risks and hazards associated with blood transfusion is an important step in helping to reshape the medical staffs' attitudes about transfusion and the most cost-effective way to achieve clinical goals.
Assuntos
Anemia/prevenção & controle , Perda Sanguínea Cirúrgica/prevenção & controle , Transfusão de Sangue Autóloga/economia , Eritropoetina/uso terapêutico , Hematínicos/uso terapêutico , Anemia/diagnóstico , Anemia/tratamento farmacológico , Bancos de Sangue/economia , Bancos de Sangue/normas , Doadores de Sangue/provisão & distribuição , Transfusão de Sangue Autóloga/efeitos adversos , Transfusão de Sangue Autóloga/estatística & dados numéricos , Darbepoetina alfa , Epoetina alfa , Eritropoetina/administração & dosagem , Eritropoetina/análogos & derivados , Eritropoetina/economia , Hematínicos/administração & dosagem , Hematínicos/economia , Hemodiluição/estatística & dados numéricos , Custos Hospitalares , Humanos , Reembolso de Seguro de Saúde , Medicare , Proteínas RecombinantesRESUMO
BACKGROUND: The main object of this study was to find out what treatment methods are currently preferred for central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO) in Germany, Austria and Switzerland. METHODS: A questionnaire concerning the different medicamentous, surgical and laser treatments available for CRVO and BRVO was developed and sent out to the members of the German Retina Society. RESULTS: This analysis is based on 124 returned questionnaires. We found that 64% of our colleagues recommend isovolemic hemodilution in patients with CRVO. Pentoxyfyllin infusions are endorsed by 32% and 27%, respectively, for CRVO and BRVO. Panretinal photocoagulation is applied only if neovascularization is present by 39% of those responding, whereas 61% perform prophylactic photocoagulation when there is no visible neovascularization, depending on the degree of ischemia. In the case of macular edema due to BRVO 52% recommend macular grid photocoagulation. Sheathotomy is recommended by 51% for BRVO suggest, and 43% advise radial optic neurotomy (RON) for CRVO. Intravitreal injection of triamcinolone is performed for CRVO or BRVO by 58% and 56%, respectively, and para-bulbar injection of triamcinolone by 2% and 3%. Intravitreal anti-VEGF treatment is applied by 72% of respondents, the majority (94%) using bevacizumab for this purpose. CONCLUSION: Members of the German Retina Society apply widely differing treatments in patients with CRVO and BRVO. Further clinical studies to evaluate the different therapeutic options seem necessary in order to set up guidelines for the treatment of venous retinal occlusions.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Hemodiluição/estatística & dados numéricos , Fotocoagulação/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Padrões de Prática Médica/tendências , Oclusão da Veia Retiniana/epidemiologia , Oclusão da Veia Retiniana/terapia , Inibidores da Angiogênese/uso terapêutico , Anticorpos Monoclonais Humanizados , Áustria/epidemiologia , Bevacizumab , Atenção à Saúde/estatística & dados numéricos , Atenção à Saúde/tendências , Alemanha/epidemiologia , Hemodiluição/tendências , Humanos , Inquéritos e Questionários , Suíça/epidemiologiaRESUMO
During acute normovolemic hemodilution (ANH), autologous whole blood is collected in a series of collection bags containing anticoagulant. The effect of hemodilution on the actual hematological constituents of this sequestered whole blood product has never been examined. We developed a mathematical model that predicts how whole blood bag constituents change during ANH to elucidate the theoretical basis for ANH efficacy. Formulas were derived to calculate the effect of ANH on [X], the blood constituent of interest. An exponential envelope was defined so that the projected impact of ANH on each constituent could be computed while initial blood volume and whole blood bag volume (WB(ANH)) were manipulated. Equivalency of autologous whole blood hemoglobin, platelets, and fibrinogen were determined by comparison with standard allogeneic blood products. We determined that the concentration of blood constituent X in a particular unit of collected blood ([X](n)) is provided as a fraction of the initial concentration ([X](0)). As WB(ANH) increases relative to estimated blood volume, the decrement in [X](n) increases in successive blood collection bags. Irrespective of initial blood volume, the equivalence of a 450-mL autologous whole blood bag to 1 U of packed red cells and 1 U of whole blood-derived platelet concentrate is 13.3 g/dL and 123 x 10(3)/microL, respectively. The impact of ANH on autologous whole blood constituents may be accurately predicted using this model. Conversion of WB(ANH) into equivalent allogeneic blood products could provide a useful method of comparing outcome in various ANH studies. The exponential envelope may be used to assess the actual ANH technique performed by the anesthesiologist, which in turn may impact quality assurance standards.
Assuntos
Preservação de Sangue , Transfusão de Sangue Autóloga , Hemodiluição , Modelos Biológicos , Preservação de Sangue/métodos , Preservação de Sangue/estatística & dados numéricos , Transfusão de Sangue Autóloga/métodos , Transfusão de Sangue Autóloga/estatística & dados numéricos , Determinação do Volume Sanguíneo/métodos , Hemodiluição/métodos , Hemodiluição/estatística & dados numéricos , Valor Preditivo dos TestesRESUMO
Standard heart-lung machines lead to substantial hemodilution with associated impaired organ function and increased need for blood transfusions. The aim of this study was to evaluate the effect of the new PRECiSe low prime volume system on perioperative myocardial damage, hemodilution, and transfusions. In a case-matched prospective study, 40 patients undergoing coronary artery bypass surgery using PRECiSe were compared with 40 patients on a standard heart-lung machine. In the PRECiSe group, the prime volume was significantly reduced, resulting in less hemodilution and transfusion requirements during and after extracorporeal circulation: only 10% of patients needed transfusions vs. 35% in the control group, with an average transfusion need of 0.16 vs. 1.25 units. There were no significant differences in perioperative cardiac-specific enzymes. The PRECiSe system was considered safe and effective for coronary artery bypass surgery.
Assuntos
Transfusão de Sangue/estatística & dados numéricos , Ponte Cardiopulmonar/instrumentação , Ponte Cardiopulmonar/métodos , Circulação Extracorpórea/instrumentação , Máquina Coração-Pulmão/normas , Hemodiluição/estatística & dados numéricos , Perda Sanguínea Cirúrgica/prevenção & controle , Circulação Extracorpórea/efeitos adversos , Circulação Extracorpórea/métodos , Feminino , Máquina Coração-Pulmão/efeitos adversos , Humanos , Complicações Intraoperatórias/prevenção & controle , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos , Resultado do TratamentoRESUMO
UNLABELLED: Quantitative changes of hemostasis during hemodilution remain unclear. With the increasing popularity of artificial blood substitutes (ABS), which solely provide oxygen-transport capacity, this issue becomes even more complex. We developed a mathematical model to quantitatively analyze hemostasis during hemodilution and validated it by recalculating patient data. We calculated and compared maximal allowable blood losses (MABL) related to minimal acceptable hematocrit, platelet concentration, and plasma fibrinogen concentration. MABL is the maximal blood loss that can be tolerated without any additional blood products. The variable with the smallest MABL thus limits hemodilution foremost. Hemodilution included isovolemic replacement of blood loss with colloid or acute normovolemic hemodilution (ANH) followed by isovolemic replacement of blood loss with colloid and ABS. We also related our findings to preoperative patient data (n = 204). The decline in platelet concentrations rarely (<2% of all patients) limits hemodilution. By contrast, critical plasma fibrinogen (< or =100 mg/dL) concentrations can often (< or =20% of all patients) limit hemodilution if their initial concentrations are within the lower normal range (<300 mg/dL). These findings become more frequent if ANH is combined with ABS. Under those circumstances ANH blood products are solely required for stabilization of hemostasis, thereby defeating the original purpose of combining ANH with ABS. IMPLICATIONS: The causes of quantitative changes of hemostasis during hemodilution, as well as their clinical effect and relevance, remain unclear. Using a validated, realistic mathematical model, we demonstrate that hemostasis, especially plasma fibrinogen, can limit the extent of hemodilution. This phenomenon is particularly prominent when acute normovolemic hemodilution is combined with artificial blood substitutes.
Assuntos
Hemodiluição/estatística & dados numéricos , Hemostasia/fisiologia , Perda Sanguínea Cirúrgica/fisiopatologia , Substitutos Sanguíneos/administração & dosagem , Substitutos Sanguíneos/uso terapêutico , Volume Sanguíneo/fisiologia , Contagem de Eritrócitos , Fibrinogênio/análise , Hematócrito , Humanos , Período Intraoperatório , Modelos Estatísticos , Contagem de Plaquetas , Estudos Prospectivos , Reprodutibilidade dos TestesRESUMO
BACKGROUND: The blood volume that has to be exchanged for crystalloids and/or colloids during acute normovolemic hemodilution (ANH) in order to reach a preset target hemoglobin concentration (hb) is usually predicted by the Bourke and Smith formula developed in 1974. This formula systematically overestimates the 'true' exchangeable blood volume (EBV), a fact that may potentially endanger patients because the target hb will be missed and the normovolemic anemia might turn out to be more severe than a priori intended. Our objective was to develop a more accurate mathematical model of hemodilution kinetics and to validate this new model in animals and in patients undergoing ANH. METHODS: Twenty-two anesthetized beagle dogs and 18 patients under balanced anesthesia underwent isovolemic hemodilution with hydroxyethyl starch (HAES 6%, 200 000) to a target hb of 7 g dl-1 or 9 g dl-1, respectively. Exchangeable blood volume predicted by use of the different mathematical models was compared with the blood volume actually exchanged to meet the preset target hb. RESULTS: Calculation of EBV by the Bourke and Smith formula (EBVB + S) systematically overestimated the volume actually exchanged (overestimation: dogs 15%, patients 20%), whereas our new iterative model predicted EBV (EBViterative) more reliably (overestimation: dogs 1%, patients 8%). In both cases EBVB + S differed significantly from the EBViterative. CONCLUSION: Exchangeable blood volume is predicted more accurately by the new iterative model than by the Bourke and Smith formula. The iterative model leads to an improvement in patient safety and provides a physiologically adequate basis for future studies investigating the efficacy of ANH in reducing allogenic blood transfusions.
Assuntos
Volume Sanguíneo/fisiologia , Hemodiluição/estatística & dados numéricos , Algoritmos , Animais , Cães , Contagem de Eritrócitos , Hemoglobinas/análise , Verde de Indocianina , Cinética , Modelos Estatísticos , Valor Preditivo dos TestesRESUMO
GOAL OF THE STUDY: To determine over a whole country what are the factors associated with an intraoperative homologous blood transfusion and with the use of autologous techniques (preoperative autologous blood donation: PABD; acute normovolemic hemodilution: ANVH; intraoperative red cell salvage: IRCS). STUDY DESIGN: National enquiry using a large representative sample (3 days of anaesthesia in France). METHODS: Univariate followed by multivariate analyses of data gathered in 1996 during the survey leaded by the French society of anaesthesia and intensive care (Sfar) and corresponding to 884 scheduled hip and knee prosthesis surgical procedures. RESULTS: Factors associated with a decreased use of PABD programme were: 1--old age and high ASA physical status; 2--procedures of short duration. By contrast, an increased use of PABD was associated with anaesthetics in which a closed circuit had been used. Except for a significant association with increasing age and with absence of PABD used, no additional factor was found to be linked with ANVH. No factor among those studied was found related to the use of IRCS. Homologous blood transfusion was more frequently used in ASA > or = 3 patients, in long duration surgeries while its use was decreased in patients with PABD (odds ratio--for reduction by PABD: 4.4 [95% confidence interval: 2.2-8.8]). Homologous blood transfusion was not related to the use of ANVH or IRCS. CONCLUSION: These data obtained from a large national survey confirm previously published studies and meta-analyses and are in agreement with current recommendations. An unexpected relation between PABD and closed circuit anaesthesia has been found.
Assuntos
Anestesia , Artroplastia de Quadril , Artroplastia do Joelho , Transfusão de Sangue Autóloga , Idoso , Transfusão de Sangue Autóloga/estatística & dados numéricos , Transfusão de Eritrócitos/estatística & dados numéricos , Feminino , França , Hemodiluição/estatística & dados numéricos , Humanos , Período Intraoperatório , Masculino , Pessoa de Meia-Idade , Análise MultivariadaRESUMO
There are a number of problems with allogeneic blood transfusion. Some of these problems are defined and can be quantified, such as the problem of rising cost or the risk of viral infection, but some of the problems are not well defined and it is only outcome data that point to allogeneic blood transfusion contributing to patient mortality and morbidity. Autotransfusion includes any technique in which the patient's own blood is collected, processed and stored, followed by reinfusion when circumstances dictate. In the perioperative period of cardiac surgery, a number of techniques are recognized as useful in this context. Preoperative autologous donation, with or without erythropoietin supplementation, intraoperative acute normovolaemic haemodilution, intraoperative cell salvage, postoperative cell salvage (reinfusion of shed mediastinal blood) and platelet rich plasmapheresis are all techniques which are used with more or less enthusiasm to reduce the need for an allogeneic blood transfusion. Modification of the priming technique of the cardiopulmonary bypass circuit using an autologous blood prime is included in this review even though it does not fall strictly within the definition of autotransfusion. Although autotransfusion is not the answer to every problem, there is no doubt that it should play a significant part in the strategy of blood conservation.
Assuntos
Transfusão de Sangue Autóloga , Procedimentos Cirúrgicos Cardíacos , Perda Sanguínea Cirúrgica , Preservação de Sangue , Transfusão de Sangue/economia , Transfusão de Sangue Autóloga/economia , Transfusão de Sangue Autóloga/métodos , Transfusão de Sangue Autóloga/estatística & dados numéricos , Análise Custo-Benefício , Custos e Análise de Custo , Procedimentos Cirúrgicos Eletivos , Desenho de Equipamento , Eritropoetina/uso terapêutico , Hemodiluição/métodos , Hemodiluição/estatística & dados numéricos , Humanos , Infecções/sangue , Infecções/transmissão , Cuidados Intraoperatórios , Tempo de Internação , Mediastino , Estudos Multicêntricos como Assunto , Seleção de Pacientes , Plasmaferese , Transfusão de Plaquetas , Reação Transfusional , Reino UnidoRESUMO
Concern over safety of the blood supply has led to the use of technologies to reduce allogeneic blood transfusion. The objective of this research was to determine the utilization of these technologies in the United States. We evaluated the following techniques: preoperative autologous donation (PAD), cell salvage (CS) and acute normovolemic haemodilution (ANH); and the following pharmaceuticals: aprotinin (APR), epsilon-aminocaproic acid (EACA), tranexamic acid (TXA), desmopressin (DDAVP) and recombinant human erythropoietin (EPO). In 1997, we conducted a cross-sectional mail survey of service chiefs at 1000 US hospitals randomly selected and stratified by status as a provider of open-heart surgery, geographical location and hospital bed size. Sixty-nine per cent (690) of hospitals responded to at least one of the four surveys sent to each hospital. Hospitals reported use of techniques more than pharmaceuticals (P < 0.001); PAD (83%, n = 206) and CS (82% n = 420) were used most frequently. Lack of familiarity was the most common reason cited for infrequent use of pharmaceuticals. Organizational characteristics (e.g. provision of open-heart surgery, size, geographical location, teaching status and type of hospital) were differentially associated with technology use. There is greater use of techniques than pharmaceuticals in US hospitals to reduce the need for allogeneic blood in the peri-operative setting. Providing open-heart surgery is strongly associated with the utilization of these technologies.
Assuntos
Transfusão de Sangue/estatística & dados numéricos , Transplante Homólogo/estatística & dados numéricos , Tecnologia Biomédica , Transfusão de Sangue/normas , Transfusão de Sangue Autóloga/estatística & dados numéricos , Procedimentos Cirúrgicos Cardíacos , Pesquisas sobre Atenção à Saúde , Hemodiluição/estatística & dados numéricos , Hemostáticos/uso terapêutico , Número de Leitos em Hospital , Hospitais , Humanos , Análise de RegressãoRESUMO
OBJECTIVE: Is the documentation of blood utilisation, as demanded in the guidelines of serology and transfusion medicine, a proper instrument of quality control for the use of homologous blood saving techniques? PATIENTS AND METHODS: We analysed retrospectively a list of blood utilisation based on 12,482 surgical procedures in orthopaedic surgery. This list included the type of operation, the number of transfused packed red cell units and, if applicable, the type of homologous blood saving technique (preoperative blood donation, mechanical autotransfusion and isovolaemic haemodilution). Total hip and knee replacement patients were divided in two groups according to base line haemoglobin (A: Hb > 13 mg%, B: hB < or = 13 mg%). RESULTS: The increase of the percentage of patients not receiving homologous blood achieved by blood saving techniques is more pronounced in group B. Preoperative blood donation seems to be the most effective technique with a percentage of patients not receiving homologous blood of 93% in group A and 80% in group B of total hip replacement. This high percentage cannot be improved when preoperative blood donation is combined with mechanical autotransfusion or isovolaemic haemodilution. The efficiency of mechanical autotransfusion and isovolaemic haemodilution can be improved by combination of the two techniques. CONCLUSIONS: A list of blood utilisation as presented can serve as a basis for guidelines regarding the use of homologous blood saving techniques. Moreover such a simple statistic provides a means of quality control and provides information about the likelihood of transfusion.