The use of magnesium sulfate as the primary tocolytic agent to prevent premature delivery.

The efficacy of magnesium sulfate was evaluated as the primary tocolytic agent in the management of patients at risk for premature delivery. One hundred ninety-two patients determined to be 36 weeks' gestation or less were treated. One hundred seven patients (55.7%) received an additional oral beta-mimetic agent once labor was arrested. One hundred nineteen patients had intact membranes and 73 patients had ruptured membranes. Delay of delivery of 48 hours or longer was achieved in 70.6% of the patients with intact membranes and 60.2% of patients with ruptured membranes. Intervening obstetric complications, maternal morbidity, and neonatal septic and respiratory morbidity were increased in patients with ruptured membranes compared to patients with intact membranes. Magnesium sulfate is considered to be effective tocolytic agent having minimal adverse effects in managing patients at risk for premature delivery. Its use in patients with ruptured membranes, as with any tocolytic agent, remains controversial.

Effect of adrenergic blockade on dynamics of the pregnant primate uterus (Macaca mulatta).

Unanesthetized rhesus monkeys, conditioned to restraining chairs and monitored continuously by chronically implanted sensors, were used to explore the relationships between catecholamines and uterine dynamics during late gestation. Continuous intra-aortic infusion of phentolamine produced a dose-response decrease in uterine activity and blood flow. With alpha-adrenergic blockade the circadian (Fourier) variations of uterine activity were abolished and those of uterine blood flow were reversed. Placental blood flow (by the microsphere technique) was 86.1% of control values. Beta-adrenergic blockade (propranolol) accentuated the circadian variations of uterine dynamics. Vascular resistance to both the myometrium and the placentas was increased. The data indicate that the maternal placental vasculature is the primary site of uterine vascular resistance and is susceptible to adrenergic response. The data also suggest that the extrinsic resistance produced by the myometrium is of major importance in the distribution of uterine blood flow.

Biorhythms of the primate uterus (Macaca mulatta) during labor and delivery.

The association between the documented spontaneous biorhythms of uterine activity, uterine artery blood flow, and aortaic blood pressure and the processes of labor and delivery was explored in 17 nonmedcated rhesus monkeys for 18 pregnancies. The characteristic circadian variations of higher hourly average values of uterine activity during periods of light than during periods of darkness were incorporated in a statistically distinct, predictable, and repetitive manner into the events of parturition. Variations in uterine artery blood flow reflected changes in intra-amniotic pressure. In those animals in which delivery occurred at night, a shift in maximal values of uterine activity from periods of light to periods of darkness occurred 48 to 60 hours prior to delivery. Progressive linear increases in hourly average values of frequency of contraction and aortic blood pressure consistently began 24 to 36 hours prior to delivery. These changes suggest that specific, directly related prodromal events occur within the maternal organism hours before parturition in the nonhuman primate.

Improving emergency department care of the sexual assault victin.

Victims of sexual assault face the multiple threats of disease, unwanted pregnancy, psychological trauma, and physical injury, which are further complicated by a comprehensive police investigation. An organized approach to the care of victims of sexual assault is presented, including guidelines for patient care and a discussion of police investigations, written consent forms, and physical evidence recovery kits. We recommend that the care of victims, from arrival in the emergency department until rehabilitation, be coordinated by a nurse. This specially trained individual serves as a liaison between the patient and the health professionals and police team.

Effects of biorhythms on blood flow distribution in the pregnant uterus (Macaca mulatta).

Ten rhesus monkeys were studied between 143 and 161 days of gestation. The unanesthetized animals were confined to restraining chairs and maintained in a controlled environment with continuous monitoring of spontaneous uterine dynamics. Forty-five determinations of blood flow distribution were made using radionuclide-labeled microspheres. The microsphere injections confirmed a circadian pattern of uterine blood flow. These biorhythms are related to alterations in distribution of blood flow to placental and nonplacental portions of the uterus. Myometrial blood flow is highest during the period of light. It is correlated positively to aortic blood pressure (r = 0.490, p less than 0.05) and inversely to uterine artery blood flow (r = -0.508, p less than 0.05). Placental blood flow is highest during the period of darkness. The flow rates are significantly correlated to intra-amniotic pressure (r = -0.602, p less than 0.05) but not to aortic blood pressure (r = -0.185, p less than 0.05). The data indicate that blood flow distribution in the primate uterus is modulated by factors in addition to physiologic pressure-flow relationships. Extrapolation to the human has potential significance.