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Biomedical subjects

R C Way

Publications and source records attributed to R C Way.

14 recordsLinked to original sources
PubMed2001

Pulmonary oxygen consumption: a hypothesis to explain the increase in oxygen consumption of low birth weight infants with lung disease.

OBJECTIVE: We determined pulmonary oxygen consumption (VO2lung) in low-birthweight infants with acute lung disease to help explain the greater whole-body oxygen consumption (VO2wb) in these infants with than in those without lung disease. METHODS AND MATERIALS: Eleven infants (birth weight 1,076+/-364 g; gestational age 28+/-3 weeks) undergoing mechanical ventilation for respiratory distress syndrome were studied in their first week of life. We measured VO2wb by indirect calorimetry and simultaneously determined systemic oxygen uptake (VO2Fick) as the product of cardiac output (echocardiography) and the arterial-mixed venous oxygen content difference (cooximetry) assuming that VO2wb-VO2Fick accounts for VO2lung. Right atrial blood samples were used to determine mixed venous oxygenation, and infants were excluded if samples returned saturations greater than 89%. RESULTS: VO2lung was 1.92+/-1.74 ml x kg(-1) x min(-1), representing 25% of their VO2wb (7.58+/-1.48 ml x kg(-1) x min(-1)). VO2lung was not correlated with clinical measures of acute disease severity. However, infants with the most severe changes on follow-up radiography (Edwards score 5 as assessed by radiologist blinded for VO2 data) all had a VO2lung level greater than 2.0 ml x kg(-1) x min(-1). CONCLUSION: VO2lung can account for the elevated metabolic rate in low-birthweight infants with lung injury. We speculate that this reflects in part inflammatory pulmonary processes and may herald chronic lung disease.

Acute Disease↗
PubMed1995

Effect of the arterial oxygenation level on cardiac output, oxygen extraction, and oxygen consumption in low birth weight infants receiving mechanical ventilation.

OBJECTIVE: To investigate the effects on oxygenation of targeting the higher versus the lower end of the currently recommended range for pulse oximetry (Spo2). DESIGN: Nonrandomized crossover trial with the use of within-subject comparisons (two-tailed paired t test). SETTING: Level III neonatal intensive care unit of a university hospital. PATIENTS: Twenty infants whose lungs were mechanically ventilated (mean +/- SD: birth weight, 1192 +/- 396 gm; gestational age, 28.7 +/- 2.7 weeks; age at time of study, 42 +/- 26 hours). INTERVENTIONS: The inspired oxygen concentration was adjusted to achieve Spo2 readings of 93% to 96% versus 89% to 92% (Ohmeda pulse oximeter) or 95% to 98% versus 91% to 94% (Nellcor oximeter). MEASUREMENTS: Cardiac output was measured by echocardiography, oxygen content of arterial blood samples by cooximetry, and oxygen consumption by indirect calorimetry. RESULTS: The inspired oxygen concentrations required to achieve the Spo2 target ranges were 39.8% +/- 8.3% versus 28.7% +/- 6.1% (p < 0.001). The respective arterial oxygen contents were 18.0 +/- 2.6 ml/dl versus 16.9 +/- 2.5 ml/dl (p < 0.001). Oxygen consumption was unchanged. In the lower-oxygen condition no compensatory increase in cardiac output was detected; thus the estimated mixed venous oxygen tension decreased and the oxygen extraction ratio increased. Venous admixture increased from 15% +/- 6% to 31% +/- 9% in the lower-oxygen condition (p < 0.001). CONCLUSIONS: The "low normal" Spo2 target range allowed for less oxygen exposure. No signs of mismatch between systemic oxygen delivery and demand could be detected.

Blood Gas Analysis↗
PubMed1991

Cardiopulmonary function during long-term central venous catheterization.

A prospective study was performed in an ambulatory group of infants, children, and young adults with neoplastic disorders to determine the prevalence of significant cardiopulmonary complications during long-term central venous catheterization. A cohort of 20 consecutive patients who had central venous catheters in situ for a mean of 13.5 months underwent pulmonary function testing, chest radiography, ventilation perfusion lung scintigraphy, electrocardiography, and echocardiography. No significant complications were seen. Specifically, there was no evidence of localized thrombus formation or pulmonary emboli, and no indirect evidence of pulmonary hypertension. In addition, we reviewed retrospectively the autopsy reports of 15 patients who died with central venous catheters in place. Three of these patients had superficial endocardial reactions. One patient had a right atrial mural thrombus related to the catheter, but two other patients were noted to have left atrial mural thrombi. This study demonstrates that central venous catheters can be used safely on a long-term basis in ambulatory patients requiring frequent venous access for treatment of their neoplastic disorders.

Adolescent↗
PubMed1977

A study of the salivary glycoprotein in cystic fibrosis patients and controls: fucose incorporation and protein pattern.

The incorporation of fucose to glycoprotein acceptors prepared from the saliva of Cystic Fibrosis (CF) patients was compared with the incorporation into acceptors from controls. The CF acceptor glycoprotein incorporated significantly more fucose in the presence of either patients' or control plasma. The fucosyl transferase activity in the patients' plasma was not significantly different from controls. Fucosidase activity was similar also for both groups. The protein bands of the acceptor glycoproteins from the patients' saliva differed from those of the control in number and electrophoretic mobility. On the basis of these studies of fucose incorporation we propose that glycoprotein in the salivary secretion of CF patients are qualitatively different from normal.

Cystic Fibrosis↗
PubMed1975

Serum alpha - fetoprotein levels in patients with cystic fibrosis and their parents and siblings.

Patients with cystic fibrosis (C.F.) showed raised serum levels of alpha-fetoprotein (AFP). A moderate but significant increase in serum AFP was present in their parents and some siblings. There was no correlation between the clinical severity of the disease and serum AFP concentration. Samples from control groups with gluten-induced malabsorption and bronchiectasis had normal levels. Persistent synthesis of AFP may be an associated marker of C.F. genes, and estimation of serum AFP might help in detecting heterozygote carriers in families at risk.

Bronchiectasis↗
PubMed1975

Relationship between serum cholinesterase and low density lipoproteins in children with nephrotic syndrome.

1. A significant increase in the activity of serum cholinesterase and concentration of dextran sulphate precipitable lipoproteins, cholesterol and triglycerides was observed in sixteen children with a diagnosis of nephrotic syndrome when compared with the values obtained in 22 other normal children of comparable ages. 2. In 7 children with nephrotic syndrome serum concentrations of beta-lipoprotein and cholinesterase were markedly higher in the acute stage compared to the convalescent stage. A working hypothesis is proposed to explain the hyperlipoproteinemia in nephrotic syndrome.

Child↗