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We evaluated the relationship between the variability in the left ventricular mass index (LVMI) and different hemodynamic factors. LVMI was associated with blood pressure and, in one subgroup, strongly to arterial pulse wave velocity (PWV). High physical activity was connected to increased LVMI, and a combination of low stroke index (SI) and high heart rate (HR) to decreased LVMI.
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Hemodinámica/fisiología , Función Ventricular , Adulto , Presión Sanguínea/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Actividad Motora/fisiología , Tamaño de los Órganos , Pulso ArterialRESUMEN
Pulmonary distribution and lung functions were evaluated during a 4-month inhaled corticosteroid treatment period in 10 steroid-naïve novel asthmatics with normal or slightly reduced lung functions. Patients were given a total daily dose of 1000 microg of beclomethasone dipropionate aerosol twice a day via a pressured metered dose inhaler with a large-volume chamber device (Volumatic, GlaxoSmith Kline, U.K.). Gamma lung scintigraphy and lung function tests were performed before and after 2 months and 4 months. Inhaled 99mTc-labelled beclomethasone dipropionate liposomes were used to assess lung deposition patterns during inhaled steroid therapy. Serum eosinophil cationic protein (ECP) concentration was used as a surrogate marker of asthmatic inflammation. Following beclomethasone treatment, all lung functions were enhanced, but only FVC values showed significant improvement. The FEV1/FVC ratio remained slightly reduced in spite of inhaled corticosteroid therapy. However, the association between changes in improved FVC values and reduced ECP levels proved to be statistically significant. In lung scintigraphy, no evidence of changes in pulmonary deposition patterns were seen during the follow-up period. We conclude that inhaled corticosteroid therapy can lead to improvements in lung functions and surrogate markers of airway inflammation in novel asthma without affecting the peripheral deposition pattern of aerosols.
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Asma/tratamiento farmacológico , Beclometasona/administración & dosificación , Glucocorticoides/administración & dosificación , Pulmón/química , Ribonucleasas , Administración por Inhalación , Adulto , Asma/diagnóstico por imagen , Proteínas Sanguíneas/metabolismo , Proteínas en los Gránulos del Eosinófilo , Volumen Espiratorio Forzado/fisiología , Humanos , Pulmón/diagnóstico por imagen , Inhaladores de Dosis Medida , Persona de Mediana Edad , Cintigrafía , Radiofármacos , Pertecnetato de Sodio Tc 99m , Capacidad Vital/fisiologíaRESUMEN
The pulmonary distribution and clearance of 99m-Tc-labelled beclomethasone dipropionate (Bec)--dilauroylphosphatidylcholine (DLPC) were compared in nine asthmatic patients on inhaled steroids after a 1-week medical treatment period of long-acting beta2-agonist formoterol. The patients were given formoterol 12 microg (OxisTurbuhaler) twice daily in addition to their own regular inhaled corticosteroid therapy. Gamma lung scintigraphy and lung function tests were performed before and after formoterol treatment. The bronchodilating effect ofthe combined therapy was significant: 1-week usage of inhaled formoterol enhanced peripheral lung deposition of beclomethasone liposome and thus diminished central/peripheral deposition ratio (C/P ratio). All measured lung function values except FEV1/FVC% improved after the medication period, although statistically significant levels were not reached. A systemic positive connection was seen between enhanced lung functions and greater lung deposition measured as AUC(0-24h)/24 Beclomethasone liposome formulation maintained its long-lasting effect in connection with formoterol treatment. At the 4-h measurement, 76% of the liposome-entrapped radioactivity still remained in the lungs before and 75% after the medication period.
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Asma/tratamiento farmacológico , Beclometasona/administración & dosificación , Broncodilatadores/uso terapéutico , Etanolaminas/uso terapéutico , Glucocorticoides/administración & dosificación , Administración por Inhalación , Adulto , Anciano , Área Bajo la Curva , Asma/diagnóstico por imagen , Asma/fisiopatología , Beclometasona/uso terapéutico , Quimioterapia Combinada , Femenino , Fumarato de Formoterol , Glucocorticoides/uso terapéutico , Humanos , Liposomas , Pulmón/diagnóstico por imagen , Pulmón/fisiopatología , Masculino , Persona de Mediana Edad , Depuración Mucociliar , Cintigrafía , Pruebas de Función Respiratoria , Tecnecio , Factores de TiempoRESUMEN
BACKGROUND: Ambulatory blood pressure correlates more closely with left ventricular mass (LVM) than casual blood pressure in cross-sectional studies, but prospective evidence is very limited. OBJECTIVE: To evaluate the best predictors of LVM and change in LVM during 10 years of follow-up, in a prospective study. METHODS: At baseline, blood pressure was recorded by casual measurements and 24 h intra-arterial ambulatory monitoring. The study participants were 97 healthy, untreated, 35-45-year-old men (34 normotensive, 29 borderline hypertensive, and 34 mildly hypertensive). At 10-year follow-up, echocardiography was performed in 86 (89%) of the men; echocardiographic data were available both at baseline and at follow-up from 70 (72%) of them. Individuals who were not receiving antihypertensive medication (n = 66) were included in the prediction of LVM index (LVMI), which was analysed as a continuous variable. RESULTS: The blood pressure variables that were best in predicting the LVMI were: 24 h pulse pressure (r = 0.308, P = 0.012), night-time pulse pressure (r = 0.291, P = 0.018), daytime pulse pressure (r = 0.253, P = 0.041), and casual systolic blood pressure (r = 0.212, P = 0.088). The LVMI was best predicted by a model including 24 h pulse pressure, positive family history of hypertension, body mass index, and age (adjusted coefficients of determination (adj.R2) = 0.197; that for the casual blood pressure model was adj.R2 = 0.140). During the follow-up, LVMI increased by +7.5 g/m2 and +23 g/m2 in individuals receiving and not receiving antihypertensive medication, respectively (P = 0.015). The change in LVMI was best predicted by the change in casual pulse pressure and use of antihypertensive medication (adj.R2 = 0.102). CONCLUSIONS: Ambulatory blood pressure improved the prediction of future LVMI compared with that obtained from casual measurements. To our knowledge, this is the longest prospective follow-up to show that pulse pressure is the most significant blood pressure parameter in predicting future LVMI and change in LVMI.
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Presión Sanguínea , Cardiomegalia/diagnóstico por imagen , Ecocardiografía , Hipertensión/diagnóstico por imagen , Hipertensión/fisiopatología , Pulso Arterial , Adulto , Antihipertensivos/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Estudios de Seguimiento , Predicción , Ventrículos Cardíacos , Humanos , Hipertensión/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
OBJECTIVE: To evaluate the usefulness of blood pressure and its variability in the prediction of future blood pressure and need for antihypertensive medication. METHODS: We used WHO criteria to classify, at baseline, 97 healthy untreated male volunteers as normotensive (n = 34), borderline hypertensive (n = 29) or mild hypertensive (n = 34), with casual measurements before intra-arterial 24 h ambulatory blood pressure monitoring. After 10 years of follow-up, 87 of the men (90%) were available and their blood pressure was recorded using casual measurements and non-invasive ambulatory 24 h monitoring. RESULTS: During the follow-up, the blood pressure classification deteriorated in 35 individuals (40%) and improved in six (7%) (McNemar test, P< 0.0001). In the borderline hypertensive group, 77% became hypertensive (P= 0.03). The 24 h mean systolic blood pressure was the best predictor of follow-up casual systolic (adj.R2 = 0.420) and 24 h systolic (adj.R2 = 0.540) blood pressure. The 24 h mean diastolic blood pressure was the best predictor of follow-up casual diastolic (adj.R2 = 0.301) and 24 h diastolic (adj.R2 = 0.292) blood pressure. The baseline casual systolic blood pressure also predicted the follow-up casual systolic blood pressure relatively well (adj.R2 = 0.356), but was clearly weaker for the follow-up 24 h systolic (adj.R2 = 0.275) blood pressure. The prediction of follow-up casual diastolic (adj.R2 = 0.259) and follow-up 24 h diastolic (adj.R2 = 0.214) blood pressure by baseline casual blood pressure was even weaker. The means and variabilities of the 24 h, daytime, and night-time blood pressures were the best predictors of the need for antihypertensive medication (Cox-Snell R2 = 0.399). The characteristics of the individual did not significantly predict future blood pressure and the need for antihypertensive medication. CONCLUSIONS: The 24 h mean blood pressure was an excellent predictor of the future blood pressure and the need for antihypertensive medication. Prediction of antihypertensive medication was further improved by also using blood pressure variability. Systolic blood pressure was more predictable than diastolic blood pressure.
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Antihipertensivos/uso terapéutico , Presión Sanguínea , Hipertensión/tratamiento farmacológico , Adulto , Monitoreo Ambulatorio de la Presión Arterial , Ritmo Circadiano , Diástole , Estudios de Seguimiento , Predicción , Humanos , Hipertensión/clasificación , Masculino , Persona de Mediana Edad , SístoleRESUMEN
To estimate extracellular water volume (ECW) changes in connection with coronary artery bypass grafting operation, simultaneous ECW estimations by 51Cr-EDTA dilution and whole-body bioimpedance techniques were performed in 15 patients. The assessments of ECW were compared with patients' weighing results. Whole-body bioimpedance-derived ECW correlated significantly with 51Cr-EDTA dilution-based ECW in the pre-operative period (r=0.74; P<0.005); the bias was 0.2 +/- 1.1 l (+/-SD). In the post-operative period, the agreement between these methods was poor, the bias being 0.5 +/- 2.5 l, and no significant correlation between the methods was found (r=0.38; P>0.05). Whole-body bioimpedance-derived ECW changes correlated significantly with weight changes of the patient induced by the operation (r=0.52; P<0.05). 51Cr-EDTA dilution-based ECW changes correlated neither with weight changes (r=0.33; P>0.05) nor with bioimpedance-derived ECW changes (r=0.03; P>0.05). Alterations in radioisotope tracer distribution and loss of it due to blood leakage in the post-operative period were presumed to explain the discrepancy between dilution technique and weighing results. The results suggest that bioimpedance is a useful non-invasive method for assessment of extracellular volume changes induced by coronary artery bypass grafting operations. 51Cr-EDTA dilution-based ECW determination is not suitable in related conditions.
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Compartimentos de Líquidos Corporales/fisiología , Puente de Arteria Coronaria , Anciano , Peso Corporal , Quelantes , Radioisótopos de Cromo , Ácido Edético , Impedancia Eléctrica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cuidados Preoperatorios , Sensibilidad y EspecificidadRESUMEN
AIM: To evaluate plasma cystatin C as a marker of the glomerular filtration rate in patients with type 2 diabetes and their age and sex-matched controls. MATERIALS AND METHODS: Forty-seven patients with one decade of type 2 diabetes and 51 non-diabetic control subjects were studied. Plasma cystatin C was measured by particle-enhanced turbidimetric immunoassay in a new application for the Hitachi 704 analyzer. For comparison, plasma creatinine and creatinine clearance were measured. The plasma clearance of 51Cr-EDTA by the single injection method was utilized as reference. RESULTS: In patients with type 2 diabetes the correlation coefficient between plasma cystatin C and the plasma clearance of 51Cr-EDTA was 0.774 (Spearman's coefficient) and that between plasma creatinine and the plasma clearance of 51Cr-EDTA was 0.556 (p = 0.001 for the difference). The correlation between creatinine clearance and the plasma clearance of 51Cr-EDTA was 0.411. In receiver operating characteristic (ROC) curve analysis the diagnostic accuracy of plasma cystatin C was significantly better than that of plasma creatinine (p = 0.047) or creatinine clearance (p = 0.001). The best diagnostic efficiency (98%) for cystatin C was obtained when the cut-off limit was set at 1.32 mg/l. In the control group the correlation coefficients were: between cystatin C and the plasma clearance of 51Cr-EDTA 0.627, between creatinine and the plasma clearance of 51Cr-EDTA 0.466 and between creatinine clearance and the plasma clearance of 51Cr-EDTA 0.416. The area under the ROC plot curve of cystatin C was also greatest in the control group, but the diagnostic accuracy of cystatin C was marginally better than that of either plasma creatinine (p = 0.05) or creatinine clearance (p = 0.08). Among the control subjects various non-renal causes may have interfered with cystatin C concentrations reducing the correlations. CONCLUSIONS: Cystatin C measurement is a more sensitive and specific test for GFR in patients with type 2 diabetes than plasma creatinine or its clearance, when GFR is normal or only slightly reduced. If an elevated cystatin C concentration is found, non-renal factors have to be excluded. The turbidimetric application described here can easily be applied for most clinical chemistry analyzers and is therefore useful in daily clinical practice.
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Cistatinas/sangre , Diabetes Mellitus Tipo 2/fisiopatología , Tasa de Filtración Glomerular , Anciano , Biomarcadores , Creatina/sangre , Cistatina C , Diabetes Mellitus Tipo 2/sangre , Estudios de Evaluación como Asunto , Femenino , Humanos , Masculino , Análisis por Apareamiento , Tasa de Depuración MetabólicaRESUMEN
OBJECTIVE: To evaluate the reliability of whole-body impedance cardiography in the measurement of cardiac output after coronary artery bypass grafting operation in comparison with the thermodilution method. DESIGN: Prospective, consecutive sampling. PATIENTS: A total of 82 patients undergoing coronary artery bypass surgery were investigated. In a group of 41 patients who were intubated, cardiac output measurements were taken simultaneously with whole-body impedance cardiography and the thermodilution method within the first 3 hrs after the operation (early intensive care unit [ICU] period). In another group of 41 patients, the measurements were taken before the operation and in the second 12 hrs after cardiac surgery (late ICU period). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The agreement between the thermodilution and whole-body impedance cardiography cardiac output measurements was good before the operation, bias 0.04 +/- 1.64 L/min (n = 41), and in the late ICU period, bias 0.00 +/- 1.84 L/min (+/-2 SD) (n = 41). The results were within 20% in 81%-85% of the cases. The agreement was satisfactory in the early ICU period, bias 0.38 +/- 2.74 L/min (n = 41). It was presumed that thermal instability of the patients was one possible source of measurement errors in the thermodilution method, causing reduced agreement between the methods in this period. The repeatability values (rv = 2.83 x SDs) for whole-body impedance cardiography were 0.44 L/min before the operation, 0.30 L/min in the early ICU period, and 0.65 L/min in the late ICU period, being significantly better than for the thermodilution method (0.79, 0.51, and 1.11 L/min, respectively) in all phases of the investigation (p < .001). The agreement between the thermodilution method and whole-body impedance cardiography is similar to reported comparisons between invasive methods in analogous settings. CONCLUSIONS: Whole-body impedance cardiography reliably measures cardiac output in patients after coronary artery bypass grafting operation. The excellent repeatability of whole-body impedance cardiography enhances the value of the method in continuous monitoring of patients after the operation.
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Gasto Cardíaco , Puente de Arteria Coronaria , Enfermedad Coronaria/fisiopatología , Electrocardiografía/métodos , Monitoreo Fisiológico , Cuidados Posoperatorios/métodos , Anciano , Cateterismo Cardíaco , Unidades de Cuidados Coronarios , Enfermedad Coronaria/cirugía , Impedancia Eléctrica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Estudios Prospectivos , Arteria Pulmonar , Reproducibilidad de los Resultados , TermodiluciónRESUMEN
The pulmonary distribution and clearance of 99mTc-labelled beclomethasone dipropionate (Bec) dilauroylphosphatidylcholine (DLPC) and dipalmitoylphosphatidylcholine (DPPC) liposomes were compared in 11 healthy volunteers using gamma scintigraphy. As delivered by using the Aerotech jet nebulizer both liposome aerosols had a suitable droplet size (mass median aerodynamic diameter 1.3 microm) allowing deep pulmonary deposition. However, in the total drug output during the inhalation there was a relatively large difference between DLPC and DPPC of 11.4 and 3.1 microg, respectively. In a gamma camera study no significant differences existed in the central/peripheral lung deposition between the DLPC and DPPC formulations. Progressive clearance of both Tc-labelled Bec liposomes was seen: 24 h after inhalation, 79% of the originally deposited radioactivity of DLPC liposomes and 83% of that of DPPC liposomes remained in the lungs. Thus there was slightly slower clearance of inhaled liposomes using DPPC instead of DLPC. We conclude that both liposome formulations are suitable for nebulization, although aerosol clouds were more efficiently made from the DLPC liposome suspension. Our results support the view that liposome encapsulation of a drug can offer sustained release and drug action in the lower airways.
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Antiasmáticos/farmacocinética , Beclometasona/farmacocinética , Pulmón/metabolismo , 1,2-Dipalmitoilfosfatidilcolina/administración & dosificación , 1,2-Dipalmitoilfosfatidilcolina/farmacocinética , Administración por Inhalación , Adulto , Aerosoles , Antiasmáticos/administración & dosificación , Antiasmáticos/efectos adversos , Beclometasona/administración & dosificación , Beclometasona/efectos adversos , Estudios Cruzados , Portadores de Fármacos , Femenino , Humanos , Liposomas , Masculino , Persona de Mediana Edad , Nebulizadores y Vaporizadores , Compuestos de Organotecnecio/administración & dosificación , Compuestos de Organotecnecio/farmacocinética , Tamaño de la Partícula , Fosfatidilcolinas/administración & dosificación , Fosfatidilcolinas/farmacocinética , Tecnecio , Distribución TisularRESUMEN
BACKGROUND/AIMS: Quantitative cholescintigraphy has been used to evaluate biliary emptying and, by some, as a screening test for sphincter of Oddi dyskinesia in cholecystectomized patients. Our aim was to identify variables that might effect the interpretation of the scintigraphy in asymptomatic cholecystectomized volunteers. METHODOLOGY: Quantitative cholescintigraphy was performed in 37 volunteer. There were 11 males and 26 females with a median age of 49 years (range: 32-82). The time interval from cholecystectomy ranged from 1 month to 30 years (median: 5 years). Eight subjects had also undergone choledocholithotomy during the cholecystectomy operation. RESULTS: From the time of the injection of the radioisotope to the maximum activity in the liver, the percentage of clearance and the hepatic hilum-duodenal transit time were measured to be 45 and 60 min, respectively. The maximum activity obtained in the liver was 17 +/- 10 min (mean +/- SD), and the percentage of clearance at 45 min was 52 +/- 22% and at 60 min 67 +/- 20%. Hilum-duodenal transit time was 12 +/- 11 min. The gender of the volunteer and previous choledocholithotomy did not correlate with the parameters studied. The age of the volunteer and the follow-up time had a positive correlation to the time of maximum activity and negative correlation to percentage of clearance. The follow-up time also had a positive correlation to hilum-duodenal transit time. In the multivariate analysis, the time interval since cholecystectomy was the only independent variable affecting study parameters. CONCLUSIONS: The length of the time interval since cholecystectomy but not the gender, age, or previous choledocholithotomy should be taken into consideration when the results of quantitative cholescintigraphy are interpreted.
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Sistema Biliar/diagnóstico por imagen , Colecistectomía , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Conductos Biliares/diagnóstico por imagen , Sistema Biliar/fisiología , Duodeno/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Cintigrafía , Factores Sexuales , Factores de TiempoRESUMEN
OBJECTIVE: To compare the distribution and clearance of inhaled beclomethasone dipropionate (Bec)-dilauroylphosphatidylcholine (DLPC) liposomes in patients with mild and severe asthma. DESIGN: A 99mTc-labeled Bec-DLPC suspension was delivered via a nebulizer (Aerotech II). Immediately after inhalation, anterior and posterior views of the lungs and an anterior view of the oropharynx were measured by a large field gamma camera with the patient in a supine position. To evaluate the mucociliary clearance of the inhaled liposomes, anterior and posterior lung scans were repeated 1, 2, 4, and 24 h after the aerosol delivery. PATIENTS: Ten patients with mild asthma (FEV1 >80% of the predicted) and 10 patients with severe asthma (FEV1 <60% of the predicted) were included in an open, parallel group study. RESULTS: Clearance is more rapid among patients with severe asthma (p<0.0001). At the 4-h measurement, a mean of 82% (SD, 5.9) of the total pulmonary dose was detected in the lungs of patients with mild asthma while in those with severe asthma the figure was 69% (SD, 10.9). The ratio between central and peripheral deposition was significantly higher for patients with severe asthma than for those having a mild form of the disease; 1.07 (SD, 0.29) and 0.76 (SD, 0.07), respectively (p=0.008). CONCLUSIONS: Inhaled Bec-DLPC liposomes were deposited more centrally in the lower airways of patients with severe asthma than those having a milder form of the disease. The clearance of Bec-DLPC liposomes is strikingly slow in both groups of asthmatic patients. However, due to the more peripheral penetration of inhaled liposomes in patients with mild asthma, the clearance rate in this group was slower than in those with severe asthma.
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Antiasmáticos/farmacocinética , Asma/tratamiento farmacológico , Beclometasona/farmacocinética , Tecnecio , Administración por Inhalación , Adulto , Anciano , Antiasmáticos/administración & dosificación , Asma/diagnóstico por imagen , Asma/metabolismo , Asma/fisiopatología , Beclometasona/administración & dosificación , Portadores de Fármacos , Femenino , Volumen Espiratorio Forzado , Cámaras gamma , Humanos , Liposomas , Pulmón/diagnóstico por imagen , Pulmón/metabolismo , Masculino , Persona de Mediana Edad , Nebulizadores y Vaporizadores , Fosfatidilcolinas , CintigrafíaRESUMEN
OBJECTIVE: To evaluate the reliability of whole-body impedance cardiography with electrodes on wrists and ankles in the measurement of cardiac output compared with the thermodilution method. DESIGN: Prospective, clinical investigation. SETTING: Surgical intensive care unit and operating room at a university hospital. PATIENTS: Simultaneous cardiac output measurements by thermodilution and whole-body impedance cardiography were performed in 74 patients undergoing a coronary artery bypass grafting operation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 97 triplicate, simultaneous cardiac output measurements were carried out with thermodilution and whole-body impedance cardiography: 74 measurements were conducted in patients who were awake and 23 measurements were conducted during anesthesia but before the commencement of surgery. The mean cardiac output difference (bias) between the two methods was 0.25 +/- 0.81 (SD) L/min; the limits of agreement (2 SD) were-1.37 and 1.87 L/min, respectively. The repeatability value (rv = 2.83 x SD) for whole-body impedance cardiography (rv = 0.46 L/min) was considerably better than for the thermodilution method (rv = 1.05 L/min). Whole-body impedance cardiography reliably detected cardiac output changes induced by head-up tilt before anesthesia, by anesthesia induction, and by intubation. Two factors predicted the between-methods stroke volume difference: hematocrit (correlation coefficient r = -.36, r2 = .13; p < .001); and body mass index (r = .29, r2 = .08; p < .01). Using the multiple linear regression equation for correcting the stroke volume by hematocrit and body mass index, the limits of agreement (2 SD) between the methods studied were reduced to +/-1.28 L/min for cardiac output and +/-0.72 L/min/m2 for cardiac index. CONCLUSIONS: There was close agreement between whole-body impedance cardiography and thermodilution in the measurement of cardiac output in patients with coronary artery disease without cardiac shunts and valvular lesions. The repeatability of the impedance method was significantly better than the repeatability of thermodilution. Whole-body impedance cardiography can be recommended for the assessment of cardiac output and its changes in the resting state. Whole-body impedance cardiography is a feasible and handy method for noninvasive and continuous measurement of cardiac output.
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Gasto Cardíaco , Cardiografía de Impedancia/métodos , Termodilución , Femenino , Hemodinámica , Humanos , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
OBJECTIVE: To determine the reliability of whole-body impedance cardiography (ICGWB), with electrodes attached to wrists and ankles, in the measurement of cardiac output (CO) on the basis of simultaneous comparison with thermodilution (TD) and direct oxygen Fick (Fick) methods. DESIGN: Prospective clinical study. SETTING: A surgical intensive care unit at a university hospital. PATIENTS: Thirty consecutive subjects undergoing a coronary artery bypass surgery were investigated preoperatively. MEASUREMENTS: ICGWB derived CO was measured simultaneously with the TD and Fick methods to establish the biases and limits of agreement (LA) between the methods. RESULTS: The results obtained by ICGWB and the invasive methods showed good agreement. The bias and LA between COTD and COICG were 0.00 l/min: 1.37 and 1.37 l/min, respectively, and were close to those obtained between COTD and COFICK, 0.32 l/min; 1.74 and -1.10 l/min. The bias and LA between the COFICK and COICG were -0.32 l/min; -2.24 and 1.60 l/min respectively. The repeatability value of consecutive single measurements for ICGWB (RVICG = 0.57 l/min) was much better than for the TD method (RVTD = 1.10 l/min). CONCLUSION: There was close agreement between the results of the three methods in the measurement of CO. In sedated preoperative patients the accuracy of ICGWB is within clinically acceptable limits and its repeatability is excellent. ICGWB provides a useful alternative to the TD and Fick methods in cases where the pressures supplied by the pulmonary artery catheter are not essential.
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Gasto Cardíaco , Cardiografía de Impedancia/métodos , Oxígeno/análisis , Termodilución/métodos , Adulto , Anciano , Pruebas Respiratorias , Puente de Arteria Coronaria , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Cuidados Preoperatorios , Estudios Prospectivos , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVES: To analyse the association between time of onset of subarachnoid haemorrhage and diurnal blood pressure variations of ambulant normo- and hypertensive subjects. DESIGN: Retrospective, population-based study. SETTING: The population (246,000) of the Health Care District of Central Finland. PATIENTS: During 1980-1987 a total of 332 subjects in the study population had their first subarachnoid haemorrhage. The hour of onset could be obtained for 287 patients, and these form the basis of the present study. RESULTS: The onset of subarachnoid haemorrhage occurred significantly more often during the waking hours than during the night. The correlation between the hourly numbers of patients suffering a haemorrhage and the corresponding mean systolic and diastolic blood pressure values of ambulant normo- and hypertensive subjects was highly significant (r = 0.88, P < 0.001). The results were similar when the 224 patients with proved aneurysmal bleed were analysed separately (r = 0.79-0.85, P < 0.001). CONCLUSIONS: The diurnal blood pressure variations of ambulant normo- and hypertensive subjects, especially the transient blood pressure peaks reaching much higher levels of pressure during the waking hours than during the night, may be crucial in determining the time of rupture of a critically weakened aneurysm wall.
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Presión Sanguínea , Ritmo Circadiano , Hemorragia Subaracnoidea/fisiopatología , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Sueño , Hemorragia Subaracnoidea/etiología , VigiliaRESUMEN
The accuracy of the indirect standard cuff method of measurement was tested against intra-arterial blood pressure readings (Oxford method) in a series of simple clinical tests: in the sitting, supine and standing positions, during bicycle ergometer test and during recovery. The mean discrepancy between methods varied in tests from -2.3 to 12.9 mmHg for systolic blood pressure level and from -4.3 to 18.2 mmHg for diastolic blood pressure level. Blood pressure responses to other tests were analysed using the value measured in the sitting position as the reference. The mean discrepancy between the methods in test responses varied from -6.3 to 8.9 mmHg for systolic responses and from -2.3 to 20.3 mmHg for diastolic responses. The data analysis indicates that the accuracy of the indirect method varies considerably between tests and also between subjects. We conclude that at present the standard cuff method cannot replace the direct method for determining blood pressure responses and reactivity.