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S Riskin-Mashiah

Publications and source records attributed to S Riskin-Mashiah.

4 recordsLinked to original sources
PubMed2001

Cerebrovascular reactivity in normal pregnancy and preeclampsia.

OBJECTIVE: To compare cerebrovascular reactivity in normotensive and preeclamptic pregnant women. METHODS: Transcranial Doppler ultrasound was used to measure peak, end-diastolic, and mean velocities in the middle cerebral arteries of 45 normotensive and 36 preeclamptic women in the third trimester. All measurements were done in the left lateral position at baseline, during 5% carbon dioxide (CO2) inhalation, and during an isometric hand-grip test. Blood pressure (BP), heart rate, oxygen (O2) saturation, and end-tidal partial pressure of carbon dioxide (pCO2) were recorded with each Doppler measurement. The mean pulsatility index (PI), resistance index (RI), and cerebral perfusion pressure at each time was compared using two-way repeated measures analysis of variance. Cerebrovascular reactivity, calculated as the percentage change in response to each maneuver, was also compared using analysis of covariance. A post hoc power analysis was performed to evaluate the primary measures of the study (middle cerebral artery PI and RI). Using alpha error of 5%, the statistical power to identify a difference in PI and RI in women with preeclampsia compared with normotensive women was 90% and 67%, respectively. The statistical power to identify a difference in PI and RI in response to the two maneuvers was 69% and 53%, respectively. Statistical significance was set at P <.05. RESULTS: Preeclamptic women had higher baseline cerebral perfusion pressure (90.4 compared with 61.9 mmHg, P <.05) and lower PI (0.64 compared with 0.76, P <.05) and RI (0.46 compared with 0.51, P <.05) than normotensive pregnant women. In normotensive patients, both 5% CO2 inhalation and isometric hand-grip test caused a significant decrease in PI (-9.5% and -6.1%, respectively) and RI (-6.5% and -4.2%, respectively). In contrast, in preeclamptic patients there was no change in any of the middle cerebral artery parameters in response to either maneuver. CONCLUSION: Normotensive pregnant women had normal middle cerebral artery responses to both 5% CO2 inhalation and isometric hand-grip test. Preeclamptic patients had elevated baseline cerebral perfusion pressure and reduced vasodilatory responses to both tests. These findings are consistent with a state of vasoconstriction in preeclamptic women that is unresponsive to stimuli that under normal circumstances result in vasodilation.

Adult↗
PubMed1999

Cervical ripening.

Induction of labor is indicated when the benefits to either the mother or the fetus outweigh the benefits of continuing the pregnancy. The state of the cervix is clearly related to the success of labor induction and the duration of labor. In cases of unfavorable cervices, physicians usually use a ripening agent before inducing labor. Unfortunately, as reviewed in this article, the ideal ripening agent is not found yet. No method of cervical ripening has shown a consistent and significant reduction in CS rate. In fact, women with the most unfavorable cervices (Bishop score, < or = 2) still face high rates of induction failure and CS.

Abortifacient Agents, Steroidal↗
PubMed1998

Autonomic imbalance in preeclampsia: evidence for increased sympathetic tone in response to the supine-pressor test.

OBJECTIVE: To examine whether an increase in sympathetic nervous tone contributes to the augmented response to cardiovascular reflex testing in preeclamptic women. METHODS: Maternal electrocardiograms were recorded from 11 nonpregnant women and 25 normotensive and 15 preeclamptic nulliparous women at term, during periods of quiet respiration in the left-lateral position and after shifting to the supine position. Power spectral analysis was applied to epochs of 512 consecutive beat-to-beat intervals to determine the contribution of sympathetic tone, parasympathetic tone, and respiratory sinus arrhythmia to heart rate variability. RESULTS: Both normotensive and preeclamptic pregnant women showed a significant decrease in respiratory sinus arrhythmia and an increase in sympathetic tone compared with nonpregnant women. In nonpregnant and in normotensive pregnant women, shifting from the left-lateral to the supine position did not cause any change in autonomic characteristics. In contrast, preeclamptic women demonstrated a marked increase in power within the very low-frequency range representing sympathetic tone, from 288 +/- 214 to 556 +/- 322 second2/Hz, in response to the same challenge (P < .05). CONCLUSION: Third-trimester pregnancy is characterized by sympathetic overactivity. When complicated by preeclampsia, sympathetic overreactivity to cardiovascular reflex testing is observed. Our data support the notion that the pathophysiologic phenomena that characterize preeclampsia are mediated not only by circulating or locally acting vasoactive substances, but also, at least in part, by an increase in sympathetic nervous tone.

Adult↗