Biology of the neonate
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Biology of the neonate · Jan 1993
Effects of a continuous infusion of tris(hydroxymethyl)aminomethane on acidosis, oxygen affinity, and serum osmolality.
The effects of a continuous infusion of tris(hydroxymethyl)aminomethane (THAM) on pH, base excess, p50, serum osmolality, and plasma drug concentration during respiratory acidosis were studied in newborn piglets. Measurements were made during three experimental periods: (1) control period with normal blood gases; (2) hypercapnia period, and (3) hypercapnia plus THAM period (THAM infusion: 1.65 mmol/kg/h). pH decreased and paCO2 increased between control period (7.40 +/- 0.05 and 45 +/- 3 mm Hg) and hypercapnia period (7.24 +/- 0.06 and 59 +/- 2 mm Hg; p < 0.001; mean +/- SD). pH returned to baseline (7.37 +/- 0.04) during the hypercapnia plus THAM period, while paCO2 remained elevated (63 +/- 4 mm Hg). p50 increased from 30.7 +/- 5.9 to 38.3 +/- 4.7 (p < 0.05) during hypercapnia and decreased with hypercapnia plus THAM. ⋯ Serum osmolality was unchanged during the THAM infusion. We conclude that continuous infusion of THAM is effective in normalizing pH during respiratory acidosis in the piglet.
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Biology of the neonate · Jan 1992
Comparative StudyCapillary (heelstick) versus venous blood sampling for the determination of glucose concentration in the neonate.
Various sites may be used to obtain blood (plasma) for the determination of the glucose concentration in the neonate. Because multiple sites may be sampled in the same neonate, it is important to determine the variability in blood glucose concentration which may result from such sampling. ⋯ When the capillary (heelstick)-venous glucose concentration difference was compared to the mean of the capillary (heelstick) and venous glucose concentrations, a difference of +/- 0.5 mM (9 mg/dl) was noted in 3 of 25 neonates. Appropriately obtained capillary (heelstick) blood samples provide measurement of blood glucose concentration which are variable compared to venous samples, but which are probably not significant physiologically.
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Biology of the neonate · Jan 1992
Comparative StudyExtracorporeal membrane oxygenation in lambs through umbilical vessel perfusion: cardiac and hepatic complications.
Twin lambs were delivered by ceasarean section near term, aralyzed, sedated and randomly assigned to either mechanical ventilation or umbilical arteriovenous ECMO for 48 hours. Umbilical arteriovenous ECMO provided adequate gas exchange with minimal or no ventilation of the native lungs. However, at autopsy, animals treated with umbilical ECMO showed right heart dilation and liver necrosis or hemorrhage compared to their twins treated with mechanical ventilation.
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Biology of the neonate · Jan 1991
REM sleep determined using in utero penile tumescence in the human fetus at term.
To assess how REM/NREM periods can be linked to the determination of the REM/NREM sleep and/or awake state, we have investigated the relationship between the REM/NREM periods and penile tumescence in the human fetus. This study was made on 11 male fetuses from 36 to 41 weeks of gestation. Eye movement and penile tumescence were simultaneously examined with an observation window of 60 min, using two separate real-time ultrasound systems. ⋯ In all cases, the total duration of penile tumescence during the REM period against REM duration was greater than the duration of tumescence during the NREM period against NREM duration with statistical significance. This indicates that the fetal penile tumescence is strongly associated with REM period and the REM period containing penile tumescence in the human fetus can be considered equivalent to REM sleep in utero. In addition, the finding that there exists a part of the REM period lacking penile tumescence suggests the possible origin of the awake state, brought about by advances in fetal development at this stage of gestation.