American journal of perinatology
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Clinical Trial
Pressor response to cycle ergometry in the midtrimester of pregnancy: can it predict preeclampsia?
Ninety-seven primigravid patients were prospectively studied to assess the predictive value of the pressor response to aerobic exercise as a screening test for preeclampsia. The blood pressure response to cycle ergometry exercise to a maternal pulse of 140 beats/min was recorded on each subject. Each subject was studied in the second trimester of pregnancy at a mean gestational age of 23 weeks (range, 18 to 27). ⋯ An increase of diastolic pressure of 20 mm Hg with moderate cycle ergometry exercise in the second trimester may predict a subset of patients at elevated risk of preeclampsia in the third trimester. However, the positive predictive value of this 20 mm Hg pressor increase (11%) limits its applicability as a screening test. Thus, we cannot recommend the use of an exercise screening test at this time.
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Comparative Study
Effect of body position on the blood gases and ventilation volume of infants with chronic lung disease before and after feeding.
The effect of body position before and after tube feeding was evaluated in six extremely immature infants who were being mechanically ventilated because of chronic lung disease. Their mean birthweight and gestational age were 722.7 g (range, 540 to 994) and 24.9 weeks (range, 23.9 to 26.0), respectively. This study was performed at a mean postnatal age of 47.5 days (range, 21 to 85 days). ⋯ Also the prone position showed a significant decrease in heart rate before and after feeding and a tendency to decrease transcutaneous carbon dioxide tension values before feeding. There were no significant differences in minute ventilation despite increased tidal volume in the prone position, most likely due to a decrement of the spontaneous respiratory rate in the prone positioning. We conclude that the prone position may offer an advantage over the supine position in the management of extremely immature infants with chronic lung disease before and after feeding.
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We studied 16 women, at 32 weeks' or more gestation who required magnesium sulfate (MgSO4) therapy for preterm labor or preeclampsia. A 60-minute Doppler fetal heart rate (FHR) tracing, analyzed by the Oxford Sonicaid System 8000, was obtained for 1 hour before and 2 hours after each patient received intravenous MgSO4 therapy. Maternal serum Mg2+ levels were obtained at the second monitoring session. ⋯ Reduced short-term and overall variability occurred in all cases with maternal serum Mg2+ levels more than 4.6 mg/dL. Therapeutic maternal serum Mg2+ levels are linked with decreases in long-term and short-term FHR variability and acceleration counts. These findings should be considered when evaluating resting FHR baseline of patients thus treated.