Diagnostic accuracy of thromboelastometry and its correlation with the HPLC-MS/MS quantification test.

The aim of the study was to evaluate the diagnostic accuracy of thromboelastometry for assessing rivaroxaban concentrations. The accuracy of thromboelastometry was compared with the high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method, which is the gold standard for drug plasma monitoring (the reference standard). Forty-six clinically stable patients were treated with 10, 15, or 20 mg of rivaroxaban once daily (OD group) or 15 mg twice a day (BID group) (no particular indication for treatment). Patient samples were collected 2 h after the use of the medication (peak) and 2 h before the next dose (trough). The rivaroxaban plasma concentrations were determined via HPLC-MS/MS, and thromboelastometry was performed using a ROTEM® delta analyzer. There were significant prolongations in clotting time (CT) for the 10, 15, and 20 mg of rivaroxaban treatments in the OD groups. In the 15 mg BID group, the responses at the peak and trough times were similar. At the peak times, there was a positive correlation between the plasma concentration of rivaroxaban and CT (Spearman correlation rho=0.788, P<0.001) and clot formation time (rho=0.784, P<0.001), and a negative correlation for alpha angle (rho=-0.771, P<0.001), amplitude after 5 min (rho=-0.763, P<0.001), and amplitude after 10 min (rho=-0.680, P<0.001). The CT presented higher specificity and sensitivity using the cut-off determined by the receiver characteristics curve. ROTEM has potential as screening tool to measure possible bleeding risk associated with rivaroxaban plasma levels.

Diagnostic accuracy of thromboelastometry and its correlation with the HPLC-MS/MS quantification test

The aim of the study was to evaluate the diagnostic accuracy of thromboelastometry for assessing rivaroxaban concentrations. The accuracy of thromboelastometry was compared with the high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method, which is the gold standard for drug plasma monitoring (the reference standard). Forty-six clinically stable patients were treated with 10, 15, or 20 mg of rivaroxaban once daily (OD group) or 15 mg twice a day (BID group) (no particular indication for treatment). Patient samples were collected 2 h after the use of the medication (peak) and 2 h before the next dose (trough). The rivaroxaban plasma concentrations were determined via HPLC-MS/MS, and thromboelastometry was performed using a ROTEM® delta analyzer. There were significant prolongations in clotting time (CT) for the 10, 15, and 20 mg of rivaroxaban treatments in the OD groups. In the 15 mg BID group, the responses at the peak and trough times were similar. At the peak times, there was a positive correlation between the plasma concentration of rivaroxaban and CT (Spearman correlation rho=0.788, P<0.001) and clot formation time (rho=0.784, P<0.001), and a negative correlation for alpha angle (rho=−0.771, P<0.001), amplitude after 5 min (rho=−0.763, P<0.001), and amplitude after 10 min (rho=−0.680, P<0.001). The CT presented higher specificity and sensitivity using the cut-off determined by the receiver characteristics curve. ROTEM has potential as screening tool to measure possible bleeding risk associated with rivaroxaban plasma levels.

Therapeutic salivary monitoring of IV busulfan in patients undergoing hematopoietic stem cell transplantation: a pilot study.

Individual therapeutic monitoring of busulfan (BU) minimizes its toxicity and improves the therapeutic outcomes during hematopoietic stem cell transplantation (HSCT). For individual dose adjustment, several blood collections are performed that are uncomfortable for patients. The aim of this pilot study was to validate a laboratory method for quantification of BU in saliva and to present the results obtained using this protocol in HSCT patients. We performed analyses of selectivity, precision and accuracy of saliva with standard concentrations of BU using ultra-high-performance liquid chromatography with diode array detection. We also determined salivary and plasmatic concentrations of BU in six HSCT patients. Saliva exhibited excellent selectivity, precision and accuracy for quantification of BU. In the patient samples, significant correlations were noted between plasmatic and salivary concentrations of BU (r=0.97, P<0.001 in the test dose; r=0.93, P<0.001 in the adjusted dose). Passing &Bablok regression revealed good agreement between the two methods (R2=0.956 for test dose; R2=0.927 for adjusted dose). In conclusion, the saliva is safe for laboratory BU measurement. The good agreement with plasma encourages further clinical studies using saliva for BU therapeutic monitoring.

A flebografia pelvica e a laparoscopia no estudo da congestao pelvica cronica. / Pelvic phlebography and laparoscopy in the study of chronic pelvic congestion

A comparacao dos dados clinicos com os quadros flebograficos e laparoscopicos deixou a impressao de que pode haver alteracao de retorno na pelve, traduzida por um esvaziamento lento do contraste de rede venosa visceral, sem que haja ainda aspecto de varizes pelvicas, enquanto, ao contrario, nao verificamos casos com varizes evidentes a flebografia e/ou laparoscopia com tempos de esvaziamento normais. Ja em relacao a correspondencia entre os dados objetivos fornecidos pelos dois metodos de exame e a clinica de dor pelvica cronica, esta correlacao deixa muito a desejar.Comparando os resultados dos dois metodos, a taxa e de positividade foi de 85% para a laparoscopia e de 70% para a flebografia.E importante salientar que, em cinco casos em que a flebografia foi normal, a laparoscopia mostrou sinais de congestao e/ou varizes nas veias viscerais da pelve. Parece-nos, assim, que a laparoscopia apresenta sobre a flebografia pelvica por via endouterina, em nossa experiencia inicial, claras vantagens como metodo de investigacao para o estudo da circulacao de retorno na pelve