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Biomedical subjects

E F Bell

Publications and source records attributed to E F Bell.

At least 73 records · Page 4Linked to original sources
PubMed1983

Echocardiographic effects of high and low volumes of maintenance fluid administration in low-birth-weight infants.

Serial M-mode echocardiograms were performed during days 3-20 of life in 73 low-birth-weight infants randomized on day 3 of life to 'high' (n = 40) and 'low' (n = 33) fluid regimens designed to give significantly different maintenance fluid intakes (172 +/- 25 and 121 +/- 13 ml/kg/day, mean +/- SD, respectively, p less than 0.001). The groups were comparable with respect to birth weight, gestational age, incidence of respiratory distress syndrome and mean number of serial echocardiograms performed per infant (9 and 9), respectively. Calorie and electrolyte intake were not controlled in the study design. Cumulative echocardiographic data were compared by unpaired t test. Left ventricular end diastolic diameter, right ventricular end diastolic diameter, septal excursion, left ventricular posterior wall excursion and left atrial to aortic root ratio were slightly but statistically significantly larger in the 'high' fluid group. Comparison of regression coefficients showed that left ventricular end-diastolic diameter tended to rise with postnatal age in the 'high' group and fall with postnatal age in the 'low' group. Left atrial to aortic root ratio tended to fall with postnatal age in the 'low' group relative to the 'high' group. These differences in echocardiographic measurements may reflect adaptation of the circulation to a degree of chronic volume overload in low-birth-weight infants.

Aging↗
PubMed1983

A double-walled incubator alters the partition of body heat loss of premature infants.

Partitional calorimetry was used to assess the influence of a double-walled incubator (Air-Shields C-86 Isolette) on the body heat loss of eight premature newborn infants (birth weights 1.44-1.89 kg, ages 6-19 days). Each infant was studied in the same incubator with and without the inner wall. Incubator heater output was regulated by servocontrol to maintain the abdominal skin temperature at 36.5 degrees C. Operative environmental temperature was the same (mean 33.0 degrees C) in both incubators. There were no differences in body temperatures, oxygen consumption, carbon dioxide production, respiratory quotient, or evaporative water and heat losses. The double-walled incubator reduced radiant heat loss but increased convective heat loss, so that the total rate of body heat loss was unchanged.

Body Temperature Regulation↗
PubMed1982

Infants with bronchopulmonary dysplasia. Growth pattern and neurologic and developmental outcome.

We evaluate neurodevelopmental and growth outcomes of low-birth-weight infants with bronchopulmonary dysplasia (BPD). Twenty-six cases of BPD (group A) were diagnosed from 244 neonatal survivors with a low birth weight (less than or equal to 1,500 g) born in 1975, 1976, and 1977. During the same period, BPD did not develop in eight infants with a comparable neonatal course (group B) (received oxygen therapy greater than or equal to 21 days). Twenty-five infants who received O2 therapy five or fewer days had a mild clinical course and were considered controls (group C). The BPD infants suffered more asphyxia, respiratory distress syndrome, acidosis, and longer parenteral alimentation and hospitalization than group C infants. Compared with groups B and C, the BPD infants had more respiratory morbidities at 4 and 12 months (P less than .005) and more severe neurodevelopmental sequelae at 2 years.

Bronchopulmonary Dysplasia↗
PubMed1981

The role of vitamin E in the nutrition of premature infants.

Vitamin E (alpha-tocopherol) has been credited with a variety of beneficial effects in the premature newborn infant. It has been thought that deficiency of vitamin E is at least partly responsible for the anemia which often occurs 4 to 6 wk after premature birth, and routine dietary supplementation with vitamin E is frequently recommended. However, critical analysis reveals that published controlled studies of vitamin E supplementation do not agree on the magnitude or even the existence of this protective effect against anemia. Analysis of commonly used feeding practices suggests that the dietary ratio of alpha-tocopherol to polyunsaturated fatty acids is generally sufficient to prevent manifestations of vitamin E deficiency without supplementation. Large parenteral doses of vitamin E have been purported to protect premature infants exposed to oxygen-enriched environments and mechanical ventilation from the complications of retrolental fibroplasia and bronchopulmonary dysplasia. Subsequent studies, however, have not yet substantiated encouraging early reports of these protective effects. At present, there seems to be no clearly established need for supplementing the premature infant's usual dietary intake of vitamin E.

Adult↗
PubMed1980

Effect of fluid administration on the development of symptomatic patent ductus arteriosus and congestive heart failure in premature infants.

We studied 170 premature infants with birth weights between 751 and 2000 g in a randomized sequential trial comparing "high" and "low" volumes of fluid intake. Beginning on the third day of life, the low-volume group received only enough water to meet average estimated requirements, and the high-volume group received an excess of at least 20 ml per kilogram of body weight per day (mean excess, 47 ml per kilogram per day). Sequential analysis showed that the risk of patent ductus arteriosus with congestive heart failure was greater in infants receiving the high-volume regimen. Thirty-five of 85 infants in the high-volume group acquired murmurs consistent with patent ductus arteriosus, and 11 of these 35 had congestive heart failure. Only nine of 85 infants in the low-volume group had murmurs consistent with patent ductus arteriosus, and two of these nine had congestive heart failure. More cases of necrotizing enterocolitis also occurred in the high-volume group. We conclude that limitation of fluid intake to amounts estimated to meet requirements for excretion, insensible loss, and growth can reduce the risks of patent ductus arteriosus and congestive heart failure in premature infants.

Ductus Arteriosus, Patent↗
PubMed1980

The effects of thermal environment on heat balance and insensible water loss in low-birth-weight infants.

To define the neutral environmental temperature and assess the effects of deviation from that temperature on insensible water loss and heat balance, 12 premature infants were studied in a conventional incubator at four different predetermined ambient temperatures. Our method combines insensible water loss measured by a continuous read-out electronic scale with heat production as determined by open circuit measurement of oxygen consumption. An increase of 1 to 2 degrees C, to an ambient temperature above or near the top of the neutral zone, produced a significant rise in insensible water loss, from 1.90 +/- 0.76 to 3.08 +/- 1.19 ml/kg/hour (mean +/- SD), a corresponding rise in evaporative heat loss, and a fall in nonevaporative heat loss. A decrease of 1 to 2 degrees C, to a slightly subneutral ambient temperature, resulted in an increase in oxygen consumption from 5.82 +/- 0.92 to 7.45 +/- 1.50 ml/kg/minute, and an increase in total heat loss, but no change in insensible water loss and evaporative heat loss. The increased total heat loss was judged to be due entirely to a greater nonevaporative heat loss, both by convection and by radiation. The data confirm that ambient temperature is an important determinant of the magnitude and the partition of heat loss in low-birth-weight infants.

Body Temperature Regulation↗
PubMed1980

Heat balance in premature infants: comparative effects of convectively heated incubator and radiant warmer, with without plastic heat shield.

Insensible water loss, oxygen consumption, and carbon dioxide production were measured in eight premature infants under four different conditions: in conventional single-walled incubator with and without plastic heat shield, and under radiant warmer with and without heat shield. IWL was greater under the radiant warmer (3.40 +/- 1.50 ml/kg/hour, mean +/- SD) than in the incubator (2.37 +/- 1.15 ml/kg/hour) when both were compared without heat shield. Addition of the heat shield reduced IWL in the incubator (2.13 +/- 0.76 ml/kg/hour) but not under the radiant warmer (3.37 +/- 0.94 ml/kg/hour). There were no significant differences in VO2 or respiratory quotient between any two of the four study conditions.

Body Temperature Regulation↗
PubMed1980

Pharmacokinetics and echocardiographic effects of digoxin in low birth weight infants with left-to-right shunting due to patent ductus arteriosus.

Serum digoxin (DIG) levels, timed urine and M-mode echocardiograms were performed in 9 low birth weight infants with left-to-right shunting due to patent ductus arteriosus treated with DIG (40 micrograms/kg in 3 and 20 micrograms/kg in 6). Half the DIG was given initially and a quarter at 8-hourly intervals. Serum DIG levels at 24 h (1.8-7.0 ng/ml) were similar in both dose groups. One infant in the 40 micrograms/kg dose group developed Wenckebach phenomenon. Left atrial to aortic root ratio fell within 30 min and remained reduced during the ensuing 24 h (p less than 0.025). There were no significant changes in the other echocardiographic measurements. Half-life of distribution and elimination of DIG were 1.04 +/- 0.46 and 15.25 +/- 0.36 h. The alpha-phase volumes of distribution (VD) differed between the 40 and 20 micrograms/kg dose groups (2.28 +/- 0.05 vs. 1.33 +/- 0.66 liters/kg, p less than 0.025). The beta-phase VD (4.25 +/- 0.61 and 2.76 +/- 0.99, respectively) were similar. Mean urinary DIG clearance was 13.1 +/- 3.2 ml/min/1.73(2).

Digoxin↗
PubMed1979

Validity of endogenous creatinine clearance in low birthweight infants.

Despite methodologic problems, endogenous creatinine clearance is commonly used as an estimation of glomerular filtration rate (GFR). Inulin clearance was compared to endogenous creatinine clearance in a group of low birthweight infants to establish the validity of the latter. Thirty-three low birthweight infants (birthweight mean = 1600 g, gestational age mean = 33 wk) were studied between 10 hr and 10 days of age to simultaneously measure GFR by inulin and endogenous creatinine clearances. Inulin and creatinine clearances correlated directly (r = 0.738, P greater than 0.001). The slope of the regression line suggested an overestimation of GFR (inulin clearance) by creatinine clearance at the low GFR range and an underestimation at the high GFR range. The data were divided into two groups by the median inulin clearance (12.5 ml/min/1.73m2). The ratio of creatinine to inulin clearance was significantly higher in the low GFR group (1.28 +/- 0.16 vs. 0.89 +/- 0.04 SEM, n = 19, P less than 0.05). There was no difference between the two groups in plasma creatinine, birthweight, gestational age, incidence of respiratory distress, or oxygen requirements at the time of the studies. Endogenous creatinine clearance represents a good estimation of GFR (inulin clearance) in low birthweight infants. However, at the low GFR range, it represents an overestimation and at the high GFR range, an underestimation.

Bilirubin↗
PubMed1979

Vitamin E absorption in small premature infants.

The absorption of vitamin E, given by orogastric tube, was studied in premature infants who weighed less than 1.5 kg at birth. After the administration of either dl-alpha tocopherol or the acetate form, plasma tocopherol levels increased. In a second blind trial, 28 infants received either 25 units of dl-alpha tocopherol or placebo during the first six weeks of life. Plasma tocopherol levels in all treated infants were sustained in the normal adult range. The vitamin E-deficient state of premature infants can be corrected by oral therapy alone.

Administration, Oral↗
PubMed1979

Fluid and electrolyte balance in very low birth weight infants.

Correct fluid and electrolyte concentrations are essential to reduce mortality in critically ill infants. The authors list considerations in calculating the necessary maintenance volumes and emphasize the importance of continuous monitoring of data and a review and retabulation every eight hours, because requirements vary from one infant to the other, and in the same infant under different circumstances.

Electrolytes↗
PubMed1979

Anatomic confirmation of echocardiographic measurements in neonatal hearts.

Significant correlations were demonstrated between echocardiographic measurements of left ventricular wall thickness, right ventricular wall thickness, septal thickness, left ventricular mass, aortic valve excursion, pulmonary valve excursion, mitral valve excursion, and tricuspid valve excursion and the same measurements made directly on the same hearts at autopsy. A new regression formula was derived for the calculation of echocardiographic right ventricular mass in life and was found to correlate significantly with right ventricular mass measured as the sum of right ventricular wall and septal volumes at postmortem examination.

Autopsy↗