Biomedical subjects

Mila Barak

Publications and source records attributed to Mila Barak.

6 recordsLinked to original sources

PubMed2005

Effect of hematocrit on exhaled carbon monoxide in healthy newborn infants.

OBJECTIVE: We tested the hypothesis that, the red blood cell (RBC) mass, estimated by hematocrit (HCT) or hemoglobin (Hb) level, influences the carbon monoxide (CO) production rate. STUDY DESIGN: The relationship between end tidal CO corrected for ambient carbon monoxide level (ETCOc) and the RBC mass have been studied in 58 full-term infants at the mean age 4.9 hours. RESULTS: Mean ETCOc was 1.88 ppm (1.3 to 3.4 ppm). ETCOc correlated significantly with HCT (R 2=10.1%, p=0.015) and with Hb (R 2=11%, p=0.011). Infants with a capillary HCT >65% had significantly higher ETCOc (mean 1.99+/-0.49 ppm) than infants with a capillary HCT <65% (1.74+/-0.39 ppm), p=0.035. When CO production was corrected for HCT (ETCOc/HCT), this difference did not longer exist. CONCLUSIONS: In newborn infants ETCOc significantly correlates with RBC mass. Comparing different infant's CO generation rate one should take into consideration their initial RBC level. In order to adjust for the existing differences in RBC, we suggest the use of the ETCOc/HCT index.

Breath Tests↗

PubMed2005

Posttransfusion equilibration of hematocrit in hemodynamically stable neonates.

OBJECTIVE: To determine whether hematocrit obtained 15 mins after blood transfusion in hemodynamically stable neonates is significantly different from that obtained after 6 hrs. We hypothesized that the hematocrit stabilizes within the first 15 mins that follow a 3-hr blood transfusion in preterm infants. DESIGN: We prospectively studied 24 consecutive infants who received blood transfusion. Hematocrit was measured immediately before the transfusion and 15 mins and 6 hrs after the transfusion of 10 mL/kg body weight of sedimented red blood cells administered over 3 hrs. Hematocrit was measured by centrifugation of a capillary. RESULTS: There was a significant increase in hematocrit from pretransfusion values both at 15 mins and 6 hrs. The increase in hematocrit from the pretransfusion value was identical (11%) at both 15 mins and 6 hrs. CONCLUSION: The hematocrit obtained 15 mins after the end of a 3-hr blood transfusion in hemodynamically stable, anemic infants is indistinguishable from that obtained after 6 hrs in the same infants. Thus, if the increase of hematocrit is deemed insufficient at 15 mins after the transfusion, it is possible to complete the transfusion without exposing the patient to an additional donor.

Anemia↗

PubMed2004

Indomethacin-induced early patent ductus arteriosus closure cannot be predicted by a decrease in pulse pressure.

Wide pulse pressure is considered to be a sign of patent ductus arteriosus (PDA). We tested the hypothesis that, following indomethacin therapy, PDA closure is associated with a significant decrease in pulse pressure. Thirty-two ventilated preterm infants were echocardiographically diagnosed within the first 24 hours of life with PDA. Systolic, diastolic, and mean arterial blood pressures were measured prior to indomethacin treatment and after echocardiographically confirmed PDA closure. Following PDA closure, systolic and diastolic blood pressures and mean arterial pressure increased significantly without a significant change of pulse pressure (17 +/- 7 to 20 +/- 12 torr). We conclude that in preterm infants with PDA, systolic, diastolic, and mean arterial blood pressures increase significantly within first few days of life. Pulse pressure does not appear to be affected by early PDA closure. We speculate that high pulmonary resistance in the first days of life prevents significant diastolic aortic runoff and leaves pulse pressure unaffected by PDA, as well as by its closure.

Blood Pressure↗

PubMed2004

The effect of positioning on energy expenditure in preterm infants: a feasibility study.

The aim of this study was to determine the feasibility of a study of the effect of positioning on energy expenditure in preterm infants. We performed a prospective, randomized, clinical cross-over pilot study of eight healthy, appropriate weight for gestational age, gavage-fed, clinically stable preterm infants at the postmenstrual age of 30 weeks. Prior to the study and in accord with our feeding protocol, infants uniformly received either their own mother's milk or a preterm formula. Each infant was studied in four different positions after randomization to eight different sequences. Infants were studied asleep, 90 minutes after feeding, after 20 minutes of being nursed in a given position. They were cared for in a servo-controlled convective incubator during the metabolic measurements, which were performed by indirect calorimetry. Energy expenditure was not significantly affected by the body position in which the infant was studied. The difference between the highest and the lowest mean energy expenditure was 3.7% of the highest one. We conclude that attempts to minimize energy expenditure by modifying infant positioning are likely to be insignificant, from a practical standpoint, because of the nonsignificant or minimal differences in energy expenditure.

Calorimetry, Indirect↗

PubMed2004

A cluster of early neonatal sepsis and pneumonia caused by nontypable Haemophilus influenzae.

Nine premature infants developed early onset sepsis and/or pneumonia with Haemophilus influenzae during a period of 53 months (January 2000 -May 2004). Their respiratory problems were pneumonia-like rather than classic respiratory distress syndrome. In 8 of the cases, the pathogen was a beta-lactamase-negative, nontypable H. influenzae. In the remaining case, the Haemophilus identified was type d. Before January 2000, no case of beta-lactamase-negative, nontypable H. influenzae sepsis or pneumonia had been recorded.

Cause of Death↗

PubMed2003

Evaluation of a new thermometer for rapid axillary temperature measurement in preterm infants.

Mercury-in-glass thermometers are considered the "gold-standard" for temperature measurements, but require at least 4 minutes for accuracy. Electronic thermometers sample temperature measurements over a shorter period. The objective of this study was to evaluate the accuracy and reproducibility of the Penguin (Medisim, Jerusalem, Israel) and the IVAC (San Diego, CA) Temp plus II thermometers in preterm infants. Axillary temperature was obtained in 50 thermally stable preterm infants each time with the mercury-in-glass, the IVAC, and the Penguin thermometers. Analysis of variance F-test, and linear regression analyses were used to test correlation of each electronic thermometer with the mercury-in-glass one, and the effect of body weight. Temperature measurement taken with the Penguin thermometer was significantly higher than that measured with the two other ones, p < 0.001. The differences in means and in variances were not significantly different between IVAC and mercury-in-glass, while the variance of the Penguin measurement was higher than that of the two other instruments (p < 0.001). The IVAC instrument correlated more tightly with the mercury-in-glass (r = 0.89, p < 0.001) than did the Penguin (r = 0.54, p < 0.001). There was an inverse correlation between the deviation of the Penguin measurement from the mercury-in-glass and the weight of the patient ( p < 0.08), while no significant correlation was found between the deviation of the IVAC measurement from the mercury in glass and the patient's weight (p = 0.56). Measurements of axillary temperature using the Penguin thermometer in incubated preterm infants are less accurate and less reproducible than those obtained using the IVAC or the glass thermometers.

Axilla↗