RESUMEN
BACKGROUND AND OBJECTIVES: The erythropoietic response in hemodialysis patients depends on several physiologic factors. Most epidemiologic studies include the effect of these factors by representing them as confounders. This study tested the hypothesis that iron stores, inflammation, dialysis adequacy, nutritional status, and hyperparathyroidism act as nonlinear effect modifiers of the erythropoietic response and quantified the magnitude of those effects over clinically relevant ranges. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The following retrospective data from 209 hemodialysis patients receiving Epoetin alfa (Epo) were collected: monthly: predialysis hemoglobin (Hgb), transferrin saturation, serum albumin, dialysis adequacy (Kt/V); quarterly: predialysis serum ferritin and intact parathyroid hormone over a period of 13 to 69 months. The study analyzed the dynamic relationship between hemoglobin and Epo, considering nonlinear effect modification by ferritin, transferrin saturation, Kt/V, albumin, and parathyroid hormone individually. RESULTS: Maximum Hgb response to Epo was achieved for serum ferritin between 350 and 500 ng/ml, transferrin saturation greater than 30%, Kt/V greater than 1.4, and albumin greater than 3.8 g/dl. Hgb sensitivity to Epo decreases by about 30% as parathyroid hormone increases from 0 through 1000 pg/ml. CONCLUSIONS: Serum ferritin, transferrin saturation, Kt/V, serum albumin, and intact parathyroid hormone are markers of nonlinear effect modification of the erythropoietic response in hemodialysis patients.
Asunto(s)
Anemia/tratamiento farmacológico , Eritropoyesis/efectos de los fármacos , Eritropoyetina/administración & dosificación , Hematínicos/administración & dosificación , Hiperparatiroidismo/etiología , Inflamación/etiología , Hierro/sangre , Enfermedades Renales/terapia , Estado Nutricional , Diálisis Renal , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anemia/sangre , Anemia/etiología , Biomarcadores/sangre , Factores de Confusión Epidemiológicos , Relación Dosis-Respuesta a Droga , Epoetina alfa , Femenino , Ferritinas/sangre , Hemoglobinas/metabolismo , Humanos , Hiperparatiroidismo/sangre , Inflamación/sangre , Enfermedades Renales/sangre , Enfermedades Renales/complicaciones , Funciones de Verosimilitud , Modelos Logísticos , Masculino , Persona de Mediana Edad , Dinámicas no Lineales , Hormona Paratiroidea/sangre , Proteínas Recombinantes , Estudios Retrospectivos , Albúmina Sérica/metabolismo , Factores de Tiempo , Transferrina/metabolismo , Resultado del Tratamiento , Adulto JovenRESUMEN
OBJECTIVE: To compare the objective anatomic outcomes after sacral colpopexy performed with cadaveric fascia lata and polypropylene mesh. METHODS: Patients undergoing a sacral colpopexy were randomized to receive either fascia lata or polypropylene mesh in a double-blinded fashion. Data were collected at 6 weeks, 3 months, 6 months, and 1 year postoperatively. The main outcome measures were pelvic organ prolapse quantification (POP-Q) system stage and individual POP-Q points over time. Objective anatomic failure was defined as POP-Q stage 2 or more at any point during the follow-up period. Proportions of patients with objective anatomic failure at 1 year in each group were compared using the chi(2) test. Mean POP-Q points and stage at 1 year were compared by using the independent samples t test. RESULTS: One hundred patients were randomized to receive either fascia (n = 46) or mesh (n = 54). Of the 89 patients returning for 1-year follow-up, 91% (41/45) of the mesh group and 68% (30/44) of the fascia group were classified as objectively cured (P = .007). We found significant differences between the mesh and fascia groups with respect to the 1-year postoperative comparisons of points Aa, C, and POP-Q stage. There were no differences between the 2 groups with respect to points TVL (total vaginal length), GH (genital hiatus), PB (perineal body), Ap or Bp (2 points along the posterior vaginal wall). CONCLUSIONS: Polypropylene mesh was superior to fascia lata in terms of POP-Q points, POP-Q stage, and objective anatomic failure rates. LEVEL OF EVIDENCE: I.
Asunto(s)
Colposcopía/métodos , Fascia Lata/trasplante , Procedimientos Quirúrgicos Ginecológicos/métodos , Polipropilenos , Mallas Quirúrgicas , Prolapso Uterino/cirugía , Adulto , Anciano , Análisis de Varianza , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Satisfacción del Paciente , Probabilidad , Valores de Referencia , Medición de Riesgo , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Ultrasonografía Doppler , Prolapso Uterino/diagnóstico por imagenRESUMEN
BACKGROUND: The respiratory quotient (RQ) obtained from indirect calorimetry (IC), defined by the ratio carbon dioxide production (VCO2)/oxygen consumption (VO2), is affected by extremes of substrate use by the body. Underfeeding, which promotes use of endogenous fat stores, should cause decreases in the RQ, whereas overfeeding, which results in lipogenesis, should cause increases in the RQ. Marked increases in VCO2 (with subsequent increases in RQ) in response to overfeeding may cause respiratory compromise in patients with limited pulmonary reserve. Thus, variation in the RQ in response to the feeding regimen may indicate inappropriate feeding and serve as a marker for patient intolerance. This prospective, multicenter study was designed to determine the clinical use of RQ for monitoring adequacy and tolerance of nutrition support. METHODS: Patients in any 1 of 30 long-term acute care Kindred hospitals made nil orally (NPO) and placed on total parenteral or enteral feeding were eligible for this study. Arterial blood gas, serum ketones, 24-hour collection of urine urea nitrogen, and IC measurements were obtained on all. Actual volume of enteral/parenteral feeding infused over the 24 hours before performance of IC was documented. RESULTS: A total of 263 patients (mean age, 70.2 years, 57.4% male) were entered in the study. Of the 263 study patients, 88.6% required mechanical ventilation, and 92.0% received enteral tube feeding only. Overall, 41.5% of patients were overfed, receiving >110% of required calories, whereas 34.2% were underfed, receiving <90% of required calories. The ratio of calories provided/required correlated significantly with overall measured RQ (p < .0001; R2 = .16). Correcting for the metabolism of protein by calculating a nonprotein RQ (NPRQ) from a 24-hour urine urea nitrogen did not improve this correlation (p < .0001, R2 = .32). Using a measured NPRQ >1.0 to identify overfeeding had an acceptable specificity of 85.1% but a low sensitivity of 38.5%. Similarly, use of a NPRQ <0.85 to determine underfeeding had a specificity of 72.2% and a sensitivity of 55.8%. Comparing the measured NPRQ with a predicted reference RQ (based on percent infusion of carbohydrate/fat and the Lusk table) did not improve the overall use of RQ. In the majority of patients (67.7%), comparison of the measured NPRQ to the predicted value failed to differentiate appropriate (meeting 100% +/- 10% of requirements) from inappropriate feeding. Deviation of the measured NPRQ from predicted failed to identify factors unrelated to substrate use purported to affect the RQ (such as acid/base disturbances or hyper/hypoventilation). Increasing measured RQ did correlate significantly with increasing respiratory rate (p = .002, R2 = .04) and decreasing tidal volume (p = .002, R2 = .04), suggesting reduced tolerance with development of shallow rapid respirations and ventilatory compromise. CONCLUSIONS: Although changes in the overall and nonprotein RQ correlate to percent calories provided/required, low sensitivity and specificity limit its efficacy as an indicator of over- or underfeeding. The RQ should not be used to finely adjust the nutrition support regimen. Elevation of overall measured RQ > or = 1.0 may be associated with reduced tolerance and mild respiratory compromise. The clinical use of RQ is limited to a marker of test validity (to confirm measured RQ values are in physiologic range) and a marker for respiratory tolerance of the nutrition support regimen.
Asunto(s)
Dióxido de Carbono/metabolismo , Trastornos Nutricionales/diagnóstico , Apoyo Nutricional/efectos adversos , Consumo de Oxígeno/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Análisis de los Gases de la Sangre , Calorimetría Indirecta , Ingestión de Energía/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Curva ROCRESUMEN
OBJECTIVE: To report the pattern of change in the lecithin/sphingomyelin (L/S) ratio in patients with preterm premature rupture of membranes (PPROM) between 24 and 34 weeks' gestation. STUDY DESIGN: L/S was determined prospectively using transvaginally and transabdominally collected amniotic fluid from patients with PPROM between 24 and 34 weeks' gestation. Samples were collected prospectively on admission and every 48 to 96 hours until L/S was > or =2.0. All patients received intramuscular betamethasone weekly. RESULTS: Fifty-five patients were included in the study. One hundred twenty-seven samples were collected transvaginally and nine were collected transabdominally. Cox regression analysis showed that a higher initial L/S value and more advanced gestational age were associated with accelerated lung maturation. Among patients at > or =29 weeks' gestation with an initial L/S of > or =1.5 and <2.0 (n=17), 15 of 17 (88%) reached L/S > or = 2 at a mean of 3.1 +/- 1.7 days (range 1.0 to 7.0 days). With an initial L/S of > or =1.0 and <1.5 (n=16), 14 of 16 (88%) patients reached L/S > or =2 at a mean of 4.1 +/- 1.9 days (range 1.7 to 7.0 days). With an initial L/S of <1.0 (n=11), 6 of 11 (54%) patients reached L/S > or =2 at a mean of 5.0 +/- 1.6 days (range 4.7 to 6.8 days). CONCLUSION: Our data document a dramatic acceleration of fetal lung maturation among patients with PPROM at > or = 29 weeks.