RESUMEN

BACKGROUND: Tacrolimus (TAC) is the most important agent for maintenance immunosuppression and prevention of immunologic injury to the renal allograft, yet there remains no consensus on how best to monitor drug therapy. Both high TAC intrapatient variability and low TAC time in therapeutic range (TTR) have been associated with risk of de novo donor-specific antibodies (dnDSA). In this study, we hypothesized that the risk associated with high TAC coefficient of variation (CV) is a result of low TAC TTR rather than the variability itself. METHODS: We analyzed the risk of dnDSA, acute rejection, or death-censored graft loss by non-dosed-corrected TAC CV and TAC TTR during the first posttransplant year in a cohort of 538 patients with a median follow-up period of 4.1 years. RESULTS: Patients with CV >44.2% and TTR <40% (high intrapatient variability and low TTR) had a high risk of dnDSA (adjusted OR = 4.93, 95% confidence interval = 2.02-12.06, P < 0.001) and death-censored graft loss by 5 years (adjusted HR = 4.00, 95% confidence interval = 1.31-12.24, P = 0.015) when compared with patients with CV >44.2% and TTR ≥40% (high intrapatient variability and optimal TTR), while the latter patients had similar risk to patients with CV <44.2% (lower intrapatient variability). CONCLUSIONS: These data suggest that previously reported immunologic risk associated with high TAC intrapatient variability is due to time outside of therapeutic range rather than variability in and of itself when evaluating absolute non-dose-corrected TAC levels irrespective of reason or indication.

Asunto(s)

Inhibidores de la Calcineurina/uso terapéutico , Monitoreo de Drogas , Rechazo de Injerto/prevención & control , Antígenos HLA/inmunología , Inmunosupresores/uso terapéutico , Isoanticuerpos/sangre , Trasplante de Riñón , Tacrolimus/uso terapéutico , Adulto , Biomarcadores/sangre , Inhibidores de la Calcineurina/efectos adversos , Inhibidores de la Calcineurina/sangre , Femenino , Rechazo de Injerto/diagnóstico , Rechazo de Injerto/inmunología , Rechazo de Injerto/mortalidad , Supervivencia de Injerto/efectos de los fármacos , Humanos , Inmunosupresores/efectos adversos , Inmunosupresores/sangre , Trasplante de Riñón/efectos adversos , Trasplante de Riñón/mortalidad , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Tacrolimus/efectos adversos , Tacrolimus/sangre , Factores de Tiempo , Resultado del Tratamiento

RESUMEN

Patients suffering from chronic mountain sickness (CMS) have excessive erythrocytosis. Low -level cobalt toxicity as a likely contributor has been demonstrated in some subjects. We performed a randomized, placebo controlled clinical trial in Cerro de Pasco, Peru (4380m), where 84 participants with a hematocrit (HCT) ≥65% and CMS score>6, were assigned to four treatment groups of placebo, acetazolamide (ACZ, which stimulates respiration), N-acetylcysteine (NAC, an antioxidant that chelates cobalt) and combination of ACZ and NAC for 6 weeks. The primary outcome was change in hematocrit and secondary outcomes were changes in PaO2, PaCO2, CMS score, and serum and urine cobalt concentrations. The mean (±SD) hematocrit, CMS score and serum cobalt concentrations were 69±4%, 9.8±2.4 and 0.24±0.15µg/l, respectively for the 66 participants. The ACZ arm had a relative reduction in HCT of 6.6% vs. 2.7% (p=0.048) and the CMS score fell by 34.9% vs. 14.8% (p=0.014) compared to placebo, while the reduction in PaCO2 was 10.5% vs. an increase of 0.6% (p=0.003), with a relative increase in PaO2 of 13.6% vs. 3.0%. NAC reduced CMS score compared to placebo (relative reduction of 34.0% vs. 14.8%, p=0.017), while changes in other parameters failed to reach statistical significance. The combination of ACZ and NAC was no better than ACZ alone. No changes in serum and urine cobalt concentrations were seen within any treatment arms. ACZ reduced polycythemia and CMS score, while NAC improved CMS score without significantly lowering hematocrit. Only a small proportion of subjects had cobalt toxicity, which may relate to the closing of contaminated water sources and several other environmental protection measures.

Asunto(s)

Acetazolamida/uso terapéutico , Acetilcisteína/uso terapéutico , Mal de Altura/tratamiento farmacológico , Inhibidores de Anhidrasa Carbónica/uso terapéutico , Depuradores de Radicales Libres/uso terapéutico , Adulto , Mal de Altura/sangre , Mal de Altura/orina , Análisis de Varianza , Análisis de los Gases de la Sangre , Distribución de Chi-Cuadrado , Enfermedad Crónica , Cobalto/sangre , Cobalto/orina , Método Doble Ciego , Quimioterapia Combinada , Femenino , Hematócrito/métodos , Humanos , Masculino , Persona de Mediana Edad , Perú , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Resultado del Tratamiento

RESUMEN

The Model for End-Stage Liver Disease (MELD) score has reduced accuracy for liver transplantation (LT) wait-list mortality when MELD ≤ 20. Neutrophil-to-lymphocyte ratio (NLR) is a biomarker associated with systemic inflammation and may predict cirrhotic decompensation and death. We aimed to evaluate the prognostic utility of high NLR (≥4) for liver-related death among low MELD patients listed for LT, controlling for stage of cirrhosis. In a nested case-control study of cirrhotic adults awaiting LT (February 2002 to May 2011), cases were LT candidates with a liver-related death and MELD ≤ 20 within 90 days of death. Controls were similar LT candidates who were alive for ≥90 days after LT listing. NLR and other covariates were assessed at the date of lowest MELD, within 90 days of death for cases and within 90 days after listing for controls. There were 41 cases and 66 controls; MELD scores were similar. NLR 25th, 50th, 75th percentile cutoffs were 1.9, 3.1, and 6.8. NLR was ≥ 4 in 25/41 (61%) cases and in 17/66 (26%) controls. In univariate analysis, NLR (continuous ≥ 1.9, ≥ 4, ≥ 6.8), increasing cirrhosis stage, jaundice, encephalopathy, serum sodium, and albumin and nonselective beta-blocker use were significantly (P < 0.01) associated with liver-related death. In multivariate analysis, NLR of ≥1.9, ≥ 4, ≥ 6.8 were each associated with liver-related death. Furthermore, we found that NLR correlated with the frequency of circulating low-density granulocytes, previously identified as displaying proinflammatory properties, as well as monocytes. In conclusion, elevated NLR is associated with liver-related death, independent of MELD and cirrhosis stage. High NLR may aid in determining risk for cirrhotic decompensation, need for increased monitoring, and urgency for expedited LT in candidates with low MELD. Liver Transplantation 23 155-165 2017 AASLD.

Asunto(s)

Enfermedad Hepática en Estado Terminal/mortalidad , Cirrosis Hepática/mortalidad , Trasplante de Hígado , Linfocitos , Neutrófilos , Listas de Espera/mortalidad , Biomarcadores/sangre , Estudios de Casos y Controles , Enfermedad Hepática en Estado Terminal/sangre , Enfermedad Hepática en Estado Terminal/etiología , Femenino , Humanos , Cirrosis Hepática/sangre , Cirrosis Hepática/complicaciones , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pronóstico , Factores de Riesgo , Índice de Severidad de la Enfermedad

RESUMEN

Identifying which liver transplantation (LT) candidates with severe kidney injury will have a full recovery of renal function after liver transplantation alone (LTA) is difficult. Avoiding unnecessary simultaneous liver-kidney transplantation (SLKT) can optimize the use of scarce kidney grafts. Incorrect predictions of spontaneous renal recovery after LTA can lead to increased morbidity and mortality. We retrospectively analyzed all LTA patients at our institution from February 2002 to February 2013 (n = 583) and identified a cohort with severe subacute renal injury (n = 40; creatinine <2 mg/dL in the 14-89 days prior to LTA and not on renal replacement therapy [RRT] yet, ≥2 mg/dL within 14 days of LTA and/or on RRT). Of 40 LTA recipients, 26 (65%) had renal recovery and 14 (35%) did not. The median (interquartile range) warm ischemia time (WIT) in recipients with and without renal recovery after LTA was 31 minutes (24-46 minutes) and 39 minutes (34-49 minutes; P = 0.02), respectively. Adjusting for the severity of the subacute kidney injury with either Acute Kidney Injury Network or Risk, Injury, Failure, Loss, and End-Stage Kidney Disease criteria, increasing WIT was associated with lack of renal recovery (serum creatinine <2 mg/dL after LTA, not on RRT), with an odds ratio (OR) of 1.08 (1.01-1.16; P = 0.03) and 1.09 (1.01-1.17; P = 0.02), respectively. For each minute of increased WIT, there was an 8%-9% increase in the risk of lack of renal recovery after LTA. In a separate cohort of 98 LTA recipients with subacute kidney injury, we confirmed the association of WIT and lack of renal recovery (OR, 1.04; P = 0.04). In LT candidates with severe subacute renal injury, operative measures to minimize WIT may improve renal recovery potentially avoiding RRT and the need for subsequent kidney transplant. Liver Transplantation 22 1085-1091 2016 AASLD.

Asunto(s)

Lesión Renal Aguda/diagnóstico , Enfermedad Hepática en Estado Terminal/cirugía , Riñón/fisiopatología , Trasplante de Hígado/efectos adversos , Recuperación de la Función , Isquemia Tibia/efectos adversos , Lesión Renal Aguda/sangre , Lesión Renal Aguda/mortalidad , Adulto , Creatinina/sangre , Enfermedad Hepática en Estado Terminal/mortalidad , Femenino , Humanos , Pruebas de Función Renal , Trasplante de Hígado/métodos , Masculino , Persona de Mediana Edad , Guías de Práctica Clínica como Asunto , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo , Resultado del Tratamiento

RESUMEN

OBJECTIVES: Anesthesia can alter gastric and small intestinal motility, but its effect on gastroesophageal reflux (GER) is unclear. We set out to evaluate the effect of anesthesia on pH-multichannel intraluminal impedance (pH impedance) evaluation of GER. METHODS: Retrospective single-center analysis of 95 pH impedance probe studies performed in patients both with anesthesia exposure and esophagogastroduodenoscopy (n = 50) and without (n = 45). RESULTS: Increased acid reflux per hour, nonacid reflux per hour, and total reflux per hour were observed in the first 4 hours, both overall and in children 1 year or older and in both sedation groups. This difference remained for the older children without sedation by multiple regression analysis for nonacid reflux per hour and total reflux per hour. Patients using proton pump inhibitors had more nonacid reflux events per hour and total reflux events per hour regardless of sedation. CONCLUSIONS: Based on the results of the present study, there is no need to eliminate the data collected immediately after placement of the probe in children younger than 1 year of age, but in those who are 1 year or older without sedation, there may be a greater number of reflux events in the first 4 hours. The first 4 hours, therefore, should be carefully evaluated in patients older than 1 year of age. Further study is needed to provide normative data for the first 4 hours versus the later time period, both for those undergoing sedation and for unsedated patients, to validate the findings from the present study and to better understand the mechanism of GER.

Asunto(s)

Anestesia/efectos adversos , Impedancia Eléctrica , Monitorización del pH Esofágico/métodos , Reflujo Gastroesofágico/diagnóstico , Adolescente , Factores de Edad , Niño , Preescolar , Femenino , Reflujo Gastroesofágico/etiología , Reflujo Gastroesofágico/fisiopatología , Humanos , Lactante , Modelos Lineales , Masculino , Estudios Retrospectivos , Factores de Tiempo

RESUMEN

Donor age has become the dominant donor factor used to predict graft failure (GF) after liver transplantation (LT) in hepatitis C virus (HCV) recipients. The purpose of this study was to develop and validate a model of corrected donor age (CDA) for HCV LT recipients that transforms the risk of other donor factors into the scale of donor age. We analyzed all first LT recipients with HCV in the United Network for Organ Sharing (UNOS) registry from January 1998 to December 2007 (development cohort, n = 14,538) and January 2008 to December 2011 (validation cohort, n = 7502) using Cox regression, excluding early GF (<90 days from LT). Accuracy in predicting 1 year GF (death or repeat LT) was assessed with the net reclassification index (NRI). In the development cohort, after controlling for pre-LT recipient factors and geotemporal trends (UNOS region, LT year), the following donor factors were independent predictors of GF, all P < 0.05: donor age (hazard ratio [HR], 1.02/year), donation after cardiac death (DCD; HR, 1.31), diabetes (HR, 1.23), height < 160 cm (HR, 1.13), aspartate aminotransferase (AST) ≥ 120 U/L (HR, 1.10), female (HR, 0.94), cold ischemia time (CIT; HR, 1.02/hour), and non-African American (non-AA) donor-African American (AA) recipient (HR, 1.65). Transforming these risk factors into the donor age scale yielded the following: DCD = +16 years; diabetes = +12 years; height < 160 cm = +7 years; AST ≥ 120 U/L = +5 years; female = -4 years; and CIT = +1 year/hour > 8 hours and -1 year/hour < 8 hours. There was a large effect of donor-recipient race combinations: +29 years for non-AA donor and an AA recipient but only +5 years for an AA donor and an AA recipient, and -2 years for an AA donor and a non-AA recipient. In a validation cohort, CDA better classified risk of 1-year GF versus actual age (NRI, 4.9%; P = 0.009) and versus the donor risk index (9.0%, P < 0.001). The CDA, compared to actual donor age, provides an intuitive and superior estimation of graft quality for HCV-positive LT recipients because it incorporates additional factors that impact LT GF rates.

Asunto(s)

Técnicas de Apoyo para la Decisión , Selección de Donante , Enfermedad Hepática en Estado Terminal/cirugía , Supervivencia de Injerto , Hepatitis C/complicaciones , Trasplante de Hígado/métodos , Donantes de Tejidos , Adulto , Factores de Edad , Enfermedad Hepática en Estado Terminal/diagnóstico , Enfermedad Hepática en Estado Terminal/mortalidad , Enfermedad Hepática en Estado Terminal/virología , Femenino , Hepatitis C/diagnóstico , Hepatitis C/mortalidad , Humanos , Funciones de Verosimilitud , Trasplante de Hígado/efectos adversos , Trasplante de Hígado/mortalidad , Masculino , Persona de Mediana Edad , Análisis Multivariante , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Reproducibilidad de los Resultados , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos

RESUMEN

With increasing attention being paid to optimizing patient outcomes, it has been proposed that liver transplantation (LT) for individuals with elevated body mass index (BMI) values and high Model for End-Stage Liver Disease (MELD) scores may adversely affect post-LT outcomes. We investigated the impact of BMI on post-LT outcomes in the context of MELD at LT. Using United Network for Organ Sharing data, we identified all adult (≥ 18 years) primary LT recipients from March 1, 2002 to September 30, 2011. BMI categories included the following: underweight, normal, overweight, class I obese, class II obese, and class III obese (<18.5; 18.5-24.9; 25-29.9; 30-34.9; 35-39.9; ≥ 40 kg/m(2), respectively). One-year post-LT death and graft loss were modeled using Cox regression, including interactions between BMI and MELD. A total of 45,551 adult recipients were identified: 68% male; median (interquartile range [IQR]) age 55 years (IQR, 49-60 years); MELD, 19 (IQR, 13-26); and donor risk index, 1.39 (IQR, 1.12-1.69). Representations in the BMI categories were underweight (n = 863, 2%), normal (n = 13,262, 29%), overweight (n = 16,329, 36%), class I obese (n = 9639, 21%), class II obese (n = 4062, 9%), and class III obese (n = 1396, 3%). In adjusted analyses, elevated BMI was not associated with increased risk for death or graft loss. Among the underweight, there were significant interactions between BMI and MELD with respect to death (P = 0.02) and graft loss (P = 0.01), with significantly increased risks for death (hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.38-2.09; P = 0.006) and graft loss (HR, 1.45; 95% CI, 1.21-1.74; P = 0.02) among those with low MELD (≤ 26), compared to normal BMI recipients with low MELD. In conclusion, overweight and obese LT recipients do not have increased risk of death or graft loss regardless of MELD. Underweight patients are at increased risk for poor outcomes post-LT, specifically underweight recipients with low MELD have increased risk for death and graft loss. Mechanisms underlying this phenomenon warrant further investigation.

Asunto(s)

Índice de Masa Corporal , Técnicas de Apoyo para la Decisión , Supervivencia de Injerto , Trasplante de Hígado/efectos adversos , Obesidad/complicaciones , Delgadez/complicaciones , Bases de Datos Factuales , Femenino , Humanos , Estimación de Kaplan-Meier , Trasplante de Hígado/mortalidad , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Obesidad/diagnóstico , Obesidad/mortalidad , Obesidad/fisiopatología , Oportunidad Relativa , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Medición de Riesgo , Factores de Riesgo , Delgadez/diagnóstico , Delgadez/mortalidad , Delgadez/fisiopatología , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos

RESUMEN

Repeat liver transplantation (LT) is controversial because of inferior outcomes versus primary LT. A minimum 1-year expected post-re-LT survival of 50% has been proposed. We aimed to identify combinations of Model for End-Stage Liver Disease (MELD), donor risk index (DRI), and recipient characteristics achieving this graft survival threshold. We identified re-LT recipients listed in the United States from March 2002 to January 2010 with > 90 days between primary LT and listing for re-LT. Using Cox regression, we estimated the expected probability of 1-year graft survival and identified combinations of MELD, DRI, and recipient characteristics attaining >50% expected 1-year graft survival. Re-LT recipients (n = 1418) had a median MELD of 26 and median age of 52 years. Expected 1-year graft survival exceeded 50% regardless of MELD or DRI in Caucasian recipients who were not infected with hepatitis C virus (HCV) of all ages and Caucasian HCV-infected recipients <50 years old. As age increased in HCV-infected Caucasian and non-HCV-infected African American recipients, lower MELD scores or lower DRI grafts were needed to attain the graft survival threshold. As MELD scores increased in HCV-infected African American recipients, lower-DRI livers were required to achieve the graft survival threshold. Use of high-DRI livers (>1.44) in HCV-infected recipients with a MELD score > 26 at re-LT failed to achieve the graft survival threshold with recipient age ≥ 60 years (any race), as well as at age ≥ 50 years for Caucasians and at age < 50 years for African Americans. Strategic donor selection can achieve >50% expected 1-year graft survival even in high-risk re-LT recipients (HCV infected, older age, African American race, high MELD scores). Low-risk transplant recipients (age < 50 years, non-HCV-infected) can achieve the survival threshold with varying DRI and MELD scores.

Asunto(s)

Selección de Donante/normas , Enfermedad Hepática en Estado Terminal/cirugía , Rechazo de Injerto/prevención & control , Trasplante de Hígado/normas , Donantes de Tejidos , Receptores de Trasplantes , Listas de Espera , Adulto , Femenino , Rechazo de Injerto/mortalidad , Supervivencia de Injerto , Humanos , Trasplante de Hígado/mortalidad , Masculino , Persona de Mediana Edad , Reoperación/normas , Factores de Riesgo , Tasa de Supervivencia/tendencias , Resultado del Tratamiento , Estados Unidos/epidemiología

RESUMEN

The Model for End-Stage Liver Disease (MELD) score has reduced predictive ability in patients with cirrhosis and MELD scores ≤ 20. We aimed to assess whether a 5-stage clinical model could identify liver transplantation (LT) candidates with low MELD scores who are at increased risk for death. We conducted a case-control study of subjects with cirrhosis and MELD scores ≤ 20 who were awaiting LT at a single academic medical center between February 2002 and May 2011. Conditional logistic regression was used to evaluate the risk of liver-related death according to the cirrhosis stage. We identified 41 case subjects who died from liver-related causes with MELD scores ≤ 20 within 90 days of death while they were waiting for LT. The cases were matched with up to 3 controls (66 controls in all) on the basis of the listing year, age, sex, liver disease etiology, presence of hepatocellular carcinoma, and MELD score. The cirrhosis stage was assessed for all subjects: (1) no varices or ascites, (2) varices, (3) variceal bleeding, (4) ascites, and (5) ascites and variceal bleeding. The MELD scores were similar for cases and controls. Clinical states contributing to death in cases were: sepsis 49%, spontaneous bacterial peritonitis 15%, variceal bleeding 24%, and hepatorenal syndrome 22%. In a univariate analysis, variceal bleeding [odds ratio (OR) = 5.6, P = 0.003], albumin (OR = 0.5, P = 0.041), an increasing cirrhosis stage (P = 0.003), reaching cirrhosis stage 2, 3, or 4 versus lower stages (OR = 3.6, P = 0.048; OR = 7.4, P < 0.001; and OR = 4.1, P = 0.008), a sodium level < 135 mmol/L (OR = 3.4, P = 0.006), and hepatic encephalopathy (OR = 2.3, P = 0.082) were associated with liver-related death. In a multivariate model including the cirrhosis stage, albumin, sodium, and hepatic encephalopathy, an increasing cirrhosis stage (P = 0.010) was independently associated with liver-related death. In conclusion, assessing the cirrhosis stage in patients with low MELD scores awaiting LT may help to select candidates for more aggressive monitoring or for living or extended criteria donation.

Asunto(s)

Hemorragia Gastrointestinal/mortalidad , Cirrosis Hepática/diagnóstico , Fallo Hepático/diagnóstico , Trasplante de Hígado , Selección de Paciente , Listas de Espera , Adolescente , Adulto , Anciano , Causas de Muerte/tendencias , Colorado/epidemiología , Femenino , Hemorragia Gastrointestinal/etiología , Humanos , Cirrosis Hepática/complicaciones , Cirrosis Hepática/mortalidad , Fallo Hepático/complicaciones , Fallo Hepático/cirugía , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Tasa de Supervivencia/tendencias , Factores de Tiempo , Adulto Joven

RESUMEN

OBJECTIVE: To evaluate the efficacy and safety of a carbohydrate restricted versus a low fat diet on weight loss, metabolic markers, body composition, and cardiac function tests in severely obese adolescents. STUDY DESIGN: Subjects were randomly assigned to 1 of 2 diets: a high protein, low carbohydrate (20 g/d) diet (high protein, low carbohydrate, HPLC) or low fat (30% of calories) regimen for 13 weeks; close monitoring was maintained to evaluate safety. After the intervention, no clinical contact was made until follow-up measurements were obtained at 24 and 36 weeks from baseline. The primary outcome was change in body mass index Z-score for age and sex (BMI-Z) at 13, 24, and 36 weeks. RESULTS: Forty-six subjects (24 HPLC, 22 in low fat) initiated and 33 subjects completed the intervention; follow-up data were available on approximately half of the subjects. Significant reduction in (BMI-Z) was achieved in both groups during intervention and was significantly greater for the HPLC group (P = .03). Both groups maintained significant BMI-Z reduction at follow-up; changes were not significantly different between groups. Loss of lean body mass was not spared in the HPLC group. No serious adverse effects were observed related to metabolic profiles, cardiac function, or subjective complaints. CONCLUSIONS: The HPLC diet is a safe and effective option for medically supervised weight loss in severely obese adolescents.

Asunto(s)

Carbohidratos de la Dieta/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Obesidad/dietoterapia , Adolescente , Factores de Edad , Apetito , Composición Corporal , Índice de Masa Corporal , Dieta , Femenino , Humanos , Masculino , Seguridad , Factores Sexuales , Resultado del Tratamiento

RESUMEN

OBJECTIVES: To determine the proportion of acid and nonacid reflux events in children with asthma suspected to have gastroesophageal reflux (GER) using combined impedance-pH monitoring, and to determine the symptom index (SI) for nonacid and acid reflux events. STUDY DESIGN: This was a prospective study of children with asthma (age 5 months to 6 years) referred for evaluation of GER. Exclusion criteria were congenital anomalies, cerebral palsy, mental retardation, and cardiac disease. The children underwent a 20-hour multichannel intraluminal impedance (MII)-pH study. RESULTS: A total of 24 children (17 male; mean age, 33 months) were enrolled from March 2004 to February 2005. MII-pH detected 1184 reflux events, versus 419 reflux events by pH alone; 51% (605 events) were nonacid. The proportion of nonacid reflux events decreased with time elapsed from last meal (P < .0001 by Pearson's chi2 test). A total of 555 symptoms were recorded, including 331 cases of cough, 243 of which (73.4%) were not associated with a reflux event. The SI for MII-pH was significantly different than that for the pH probe (37% vs 0%; P = .008). CONCLUSIONS: Acid and nonacid reflux occurs with equal frequency in children with asthma. Most symptoms occur in the absence of a reflux event.

Asunto(s)

Asma/epidemiología , Reflujo Gastroesofágico/diagnóstico , Reflujo Gastroesofágico/epidemiología , Preescolar , Tos/diagnóstico , Tos/epidemiología , Impedancia Eléctrica , Femenino , Ácido Gástrico/química , Humanos , Concentración de Iones de Hidrógeno , Masculino , Dolor/diagnóstico , Dolor/epidemiología , Estudios Prospectivos , Factores de Tiempo