Biomedical subjects

Robert K Merritt

Publications and source records attributed to Robert K Merritt.

5 recordsLinked to original sources

PubMed2004

Fluid overload before continuous hemofiltration and survival in critically ill children: a retrospective analysis.

OBJECTIVE: Continuous venovenous hemofiltration (CVVH) is used for renal replacement and fluid management in critically ill children. A previous small study suggested that survival was associated with less percent fluid overload (%FO) in the intensive care unit (ICU) before hemofiltration. We reviewed our experience with a large series of pediatric CVVH patients to evaluate factors associated with outcome. DESIGN: Retrospective chart review. SETTING: Tertiary children's hospital. PATIENTS: CVVH pediatric ICU patients from November 1997 to January 2003. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: %FO was defined as total fluid input minus output (up to 7 days before CVVH for both hospital stay and ICU stay) divided by body weight. One hundred thirteen patients received CVVH; 69 survived (61%). Multiple organ dysfunction syndrome (MODS) was present in 103 patients; 59 survived (57%). Median patient age was 9.6 yrs (25th, 75th percentile: 2.5, 14.3). Median %FO was significantly lower in survivors vs. nonsurvivors for all patients (7.8% [2.0, 16.7] vs. 15.1% [4.9, 25.9]; p =.02] and in patients with > or =3-organ MODS (9.2% [5.1,16.7] vs. 15.5% [8.3, 28.6]; p =.01). The Pediatric Risk of Mortality Score III at CVVH initiation also was associated with survival in these groups, but by multivariate analysis, %FO was independently associated with survival in patients with > or =3-organ MODS (p =.01). CONCLUSIONS: Survival in critically ill children receiving CVVH in this large series was higher than in previous reports. CVVH survival may be associated with less %FO in patients with > or =3-organ MODS. Prospective studies are necessary to determine whether earlier use of CVVH to control fluid overload in critically ill children can improve survival.

Acute Kidney Injury↗

PubMed2003

A population-based study of the 22q11.2 deletion: phenotype, incidence, and contribution to major birth defects in the population.

OBJECTIVES: Although several studies describe the 22q11.2 deletion, population-based data are scant. Such data are needed to evaluate properly the impact, distribution, and clinical presentation of the deletion in the population. Our goals were to assess the population-based birth prevalence of the 22q11.2 deletion and its associated phenotype and its impact on the occurrence of heart defects. METHODS: We evaluated data on infants who were born from 1994 through 1999 to women who resided in metropolitan Atlanta. We matched records from the Metropolitan Atlanta Congenital Defects Program (a population-based registry with active case ascertainment), the Sibley Heart Center at Children's Healthcare of Atlanta, and the Division of Medical Genetics at Emory University. We used birth certificate data for the denominators of the rates. RESULTS: We identified 43 children with laboratory-confirmed 22q11.2 deletion among 255 849 births. The overall prevalence was 1 in 5950 births (95% confidence interval: 1 in 4417 to 1 in 8224 births). The prevalence was between 1 in 6000 and 1 in 6500 among whites, blacks, and Asians and 1 in 3800 among Hispanics. Most affected children (81%) had a heart defect, and many (1 in 3) had major extracardiac defects (other than velopalatal anomalies), including anomalies of the central nervous system. Overall, the deletion contributed to at least 1 of every 68 cases of major heart defects identified in the total birth cohort and, in particular, to 1 of every 2 cases diagnosed with interrupted aortic arch type B, 1 of every 5 with truncus arteriosus, and 1 of every 8 with tetralogy of Fallot. CONCLUSIONS: The 22q11.2 deletion was common in this birth population. The clinical phenotype included a wide and variable spectrum of major cardiac and extracardiac anomalies. From these population-based data, one can estimate that at least 700 affected infants are born annually in the United States. Population-based estimates such as these should be useful to medical professionals and policy makers in planning for the optimal care of people with the 22q11.2 deletion.

Abnormalities, Multiple↗

PubMed2003

Costs of poor birth outcomes among privately insured.

Despite expansions in the public insurance coverage of pregnant women, concerns over poor birth outcomes remain. Poor birth outcomes occur among publicly and privately insured women, however, thereby imposing excess costs on employers and their insurers. Data from a large sample of privately insured for 1996 are used to examine these outcomes and costs. Almost one-fourth (24.3 percent) of the infants in our matched sample of 12,020 deliveries was premature or had other problems at birth. Costs for these infants accounted for 82 percent of the total $56 million spent on sample infants. The incremental cost of infants with poor birth outcomes versus those with normal, full-terms was approximately $14,600. We found that these relative costs had increased over time due perhaps to the increased technology and intensity of services used to save infant lives. We also found that factors other than maternal and infant complications affected cost variations. For example, employers located in the Northeast, hiring older mothers, and in unionized sectors have higher prenatal, delivery, and infant costs.

Adult↗

PubMed2002

The challenges of developing a modern cardiac research program.

The development of a cardiac research program in the current health care setting can bring many challenges. The myriad of changing regulations involving research with vulnerable populations combined with the need to protect patient confidentiality is an issue that must be addressed in the initial stages of development. Also, the lack of an experienced workforce can often make the search for research staffing difficult at best. In 2001, Children's Healthcare of Atlanta initiated a cardiac research program. Over the last year, many obstacles have been overcome, and this experience has led to the appreciation of the challenges ahead.

Biomedical Research↗

PubMed2002

Screening for stroke in sickle cell anemia: comparison of transcranial Doppler imaging and nonimaging US techniques.

PURPOSE: To determine whether criteria for screening patients with sickle cell anemia for stroke established with a nonimaging transcranial Doppler ultrasonographic (US) technique are applicable to studies performed with a transcranial Doppler US imaging technique. MATERIALS AND METHODS: One hundred sixty-eight examinations in 66 children were performed for sickle cell stroke screening. Children were examined with nonimaging and imaging transcranial Doppler US techniques on the same day, for a total of 84 paired examinations. The time-averaged maximum mean velocity (V(mean)) and resistive index (RI) were calculated in the middle cerebral arteries, bifurcations of the distal internal carotid arteries, distal internal carotid arteries, anterior cerebral arteries, posterior cerebral arteries, and basilar arteries. The maximum systolic velocity (V(max)) was evaluated in the distal internal carotid arteries and middle cerebral arteries. V(mean), V(max), and RI measurements were subjected to repeated-measures multivariate analysis of covariance, and the Pearson product moment correlation was used for middle cerebral artery velocity, age, and hemoglobin. RESULTS: V(mean) measurements obtained with nonimaging and imaging techniques varied substantially for the bifurcation of the distal internal carotid artery, the posterior cerebral artery, and the basilar artery. Substantial differences were found in RIs for every vessel. Examination time was shorter with the nonimaging technique. CONCLUSION: V(mean) measurements in the middle cerebral artery, distal internal carotid artery, and anterior cerebral artery did not vary substantially between nonimaging and imaging transcranial Doppler US. RI data did not yield comparable measurements.

Adolescent↗