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Biomedical subjects

N H Lauersen

Publications and source records attributed to N H Lauersen.

At least 37 records · Page 2Linked to original sources
PubMed1981

A new abortion technique: intravaginal and intramuscular prostaglandin.

The 15-methyl analog of prostaglandin F2 alpha (15-ME-PGF2 alpha), administered in a 3-mg dose via a single vaginal suppository and supplemented at 24 hours by intramuscular injection(s) of 250 micrograms, successfully induced abortion in 80 of 81 patients in the midtrimester of pregnancy. The mean abortion time was 19.6 hours. Two thirds of the patients aborted after treatment with the suppository alone in a mean time of 14.6 hours; the remaining 27 patients required intramuscular injections of 15-ME-PGF2 alpha to effect expulsion of the products of conception. Twenty-six of these 27 patients subsequently aborted in a mean total abortion time of 29.6 hours. Fifty-eight patients aborted within 24 hours of the initial prostaglandin administration, and 78 aborted by 36 hours. Parity and length of gestation did not significantly affect abortion time in this series, although the mean abortion time for parous patients and patients with gestations earlier than 17 weeks tended to be somewhat shorter than that of nulliparous patients and those with more advanced gestations. The placenta was spontaneously expelled in the majority of patients. Abortion was incomplete in 3 patients and required curettage. Uterine activity, as measured via an intraamniotic catheter in 6 patients, developed very gradually with the suppository, peaking at 3 hours after insertion, and was characterized by regular contractions with low intrauterine baseline tonus. The gastrointestinal side effects that occurred in 59% of patients who received the suppository were also most frequently observed at 3 hours after administration. In contrast the gastrointestinal disturbances elicited by intramuscular injections of the analog immediately followed the administration.

Abortion, Induced↗
PubMed1981

The inhibitory effect of ethanol on oxytocin-induced labor at term.

Intravenous ethanol infusion significantly reduced oxytocin-induced uterine activity in pregnant patients at term. The dose response to oxytocin was linear when plotted log2 x in all patients studied, and the line was shifted to the right by alcohol, but the slope remained essentially unchanged. These results suggest that alcohol directly inhibits the effect of oxytocin on the myometrium, although the possibility of some central inhibition of oxytocin release cannot be discounted.

Dose-Response Relationship, Drug↗
PubMed1980

Management of intrauterine fetal death with prostaglandin E2 vaginal suppositories.

The recent Food and Drug Administration's approval of prostaglandin E2 (PGE2) vaginal suppositories provides the clinician with a technique for the immediate management of missed abortion and intrauterine fetal death (IUFD). During a 4-year period at our institution, 78 of 80 patients with gestations ranging from 13 to 42 weeks had pregnancy successfully terminated with PGE2 suppositories with a dose schedule of 20 mg every 2 hours. The mean interval from induction to delivery of the fetus was 8.9 hours. Fifty percent of the patients spontaneously expelled the placenta; active intervention to remove the placenta within 2 hours of delivery of the fetus is recommended to avoid excessive vaginal bleeding. The most frequently encountered side effect was a temperature elevation, which was managed by less frequent administration of the prostaglandin. Gastrointestinal side effects were minimized by premedication with antidiarrheal and antiemetic agents, which also were administered during the induction period when indicated by the patient's symptoms. A concomitant oxytocin infusion was utilized in 38 patients. In gestations of less than 24 weeks the oxytocin was administered via intravenous drip at a rate of 10 U/hour. In the case of a patient with IUFD and a gestation of 24 weeks or more, oxytocin should be administered only with a constant-rate infusion pump starting at a dose schedule of 1 mU/minute with careful titration of the dose against the monitored uterine activity. The availability of the vaginal PGE2 suppositories for missed abortion and IUFD makes it important for the clinician to fully acquaint himself with the drug, its administration, effects, and side effects.

Abortion, Therapeutic↗
PubMed1980

Early pregnancy interruption with two 15-ME-PGF2a suppositories.

Vaginal administration of 15-ME-PGF2a suppositories successfully terminated pregnancy, as determined by a negative pregnancy test at 14 days following insertion, in 34 of 39 patients with gestations of 34 to 51 days of amenorrhea. Fifteen of 20 patients who received a single long-acting 3-mg suppository had negative pregnancy tests at follow-up, while all 19 patients in whom the 3-mg suppository was preceded by a rapidly acting 1-mg suppository successfully aborted. This two-suppository regimen resulted in a more rapid onset of uterine activity and vaginal bleeding, as well as a slight decrease in gastrointestinal side effects. Peripheral plasma levels of 15-ME-PGF2a as detected by radioimmunoassay were also more consistent with two suppositories. It appeared that the rapidly acting 1-mg suppository provided a "prostaglandin impact" which significantly enhanced the abortifacient effectiveness of the technique. Nine patients on the 2-suppository regimen had the procedure performed on an outpatient basis. Expanded studies are indicated to determine the practicality of this technique as a valid pharmacologic alternative to surgical interruption of very early pregnancy.

Abortifacient Agents↗
PubMed1979

Preinduction cervical priming with oral prostaglandin E2.

Seventy-three women, primigravidas and multigravidas, received 1.0 mg PGE2 tablets hourly for 5 doses the evening prior to scheduled induction of term labor to improve cervical ripeness. The over-all response to treatment depended upon the initial cervical score. Gastrointestinal side effects occurred infrequently and no complications to mother or fetus were observed. While the protocol used provoked an important in cervical favorability it is anticipated that a more prolonged PGE2 administration might achieve better results.

Administration, Oral↗
PubMed1979

Continuous intrapartum monitoring of fetal scalp pH.

Forty patients were monitored intrapartum with a continuous fetal scalp tissue pH electrode in the mean time of 2.39 hours. The monitoring records were considered "accurate" with good correlation to the intermittent fetal scalp capillary pH values in 76.9 per cent. The correlation coefficient was 0.74. The "accuracy" improved in the latter 23 cases to 87 per cent with a correlation coefficient of 0.82. This improvement was probably due to modification of the application technique, as well as to a new calibration method at 37 degrees. Continuous fetal scalp pH monitoring was clinically useful in 65 per cent, it was partially useful in 20 per cent, but of no value in 15 per cent of the patients studied. There were no apparent maternal complications with the use of this technique and 38 of the infants had no sequelae. Two infants had complications: one developed inflammation of the electrode site. This was treated with antibiotics. One electrode broke during the application and a fragment of the electrode tip remained in the fetal scalp. All the infants were grossly normal and there was a good correlation between the continuous pH readings and the immediate neonatal outcome.

Adult↗
PubMed1979

Studies of oxytocin in the baboon during pregnancy and delivery.

Oxytocin was determined by radioimmunoassay in pregnant baboons throughout gestation, in the foetus at caesarean section, and after oxytocin infusion into the mother and foetus. Serial maternal plasma oxytocin in 6 baboons during pregnancy showed a significant correlation between the gestational age and maternal plasma oxytocin concentrations with a correlation coefficient of r = 0.3185 and P less than 0.005. Seventy-one out of 75 plasma samples (94.7%) during pregnancy had detectable levels of oxytocin. Uterine vein plasma had higher oxytocin concentrations than maternal plasma and amniotic fluid (18.6 +/- 4.6 pg/ml; mean +/0 SE) but lower than umbilical, jugular vein and cardiac blood from the foetus. Foetal pituitary gland contained 5.4--26.1 micrograms oxytocin/g. Regular uterine contractions were established with iv oxytocin of 4--20 mU/min and the plasma oxytocin measured showed a significant correlation with the uterine activity achieved (r = 0.64, P less than 0.001). The disappearance of plasma oxytocin at 179 days gestation gave an apparent half-life of 1.1 and 1.7 min in 2 baboons with a late half-life of 9.9 and 17.3 min, respectively. In one baboon at 171 days gestation, the apparent half-life of oxytocin was 9.9 min. The metabolic clearance rates were calculated to be 3.1, 3.2 and 11.7 ml/kg/min, respectively. The production rates were 97, 74, 390 pg/kg/min, respectively. Oxytocin injected into the umbilical vessel near term showed an increase in oxytocin concentration in maternal and uterine vein plasma and amniotic fluid, suggesting that oxytocin can cross the placenta from the foetal to the maternal side. Our findings indicate that in the baboon (1) oxytocin is present throughout pregnancy, (2) uterine activity can be correlated with plasma oxytocin during oxytocin infusion, (3) foetal circulation has higher oxytocin concentration than maternal blood and (4) oxytocin probably can cross the placenta from the foetus to the mother.

Amniotic Fluid↗
PubMed1978

A study of the pH monitor in cats.

A study of the accuracy of the tpH electrode was performed in 10 cats. Hypoxia and acidosis were produced by ventilatory means and bicarbonate infusions were used to elevate the pH . Tissue pH correlated well with arterial (r = 0.9) within the physiological rates of change of pH. Prolonged tissue acidosis lead to eventual death. The correct and stable mechanical fixation of the pH electrode is a critical factor in assuring accurate results. The ROCHE tpH electrode accurately reflects arterial pH, and a correlation coefficient of at least 0.85 should be attainable in the human fetus.

Animals↗
PubMed1978

Evaluation of continuous fetal scalp pH during labor.

Continuous monitoring of fetal scalp tissue pH was technically acceptable in 79.4% of 35 patients sequentially studied. Overall, the correlation coefficient (r) between the continuous pH readings and the intermittent pH values was 0.75. The accuracy improved greatly in the latter 23 patients. This was probably due to improved skills of the operators but also to a revision of the calibration technique. The correlation coefficient in these 23 patients was 0.82, and 87% of the records were accurate. The mean monitoring time was 2.39 h and eight infants were monitored throughout delivery and post natal. Although good results were obtained in this study, the method still demands technical skill in order to achieve clinically useful results.

Adolescent↗
PubMed1978

Variable range directional doppler and abdominal ECG for FHR monitoring.

Antepartum nonstress fetal heart rate (FHR) monitoring may become a valuable screening tool for all pregnancies. Two methods proposed for an antepartum FHR monitor are examined: abdominal electrocardiogram (AECG) and variable range directional Doppler (RDD). A good quality (detailed, clearcut baseline) RDD FHR record was obtained in 74/75 (99%) examinations, and a good quality AECG record was obtained i31/75 (41%). Each patient was monitored in the supine, lateral and sitting positions. Considering all positions, 76% of the RDD records and 19% of the AECG records were good. The RDD system was efficacious for routine, clinical antepartum FHR monitoring, but the performance of the AECG was too limited for this purpose.

Doppler Effect↗
PubMed1978

Microfilm storage of fetal monitoring records: a practical solution.

Microfilming of fetal monitoring records has, at our institution, been found to be a practical method for storage of recording papers from fetal monitoring. This system permits a reduction of the records by a factor of 20:1 and up to 7.64 hours of fetal monitroing records will fit into a 4 x 6 inch film jacket. This microfilm record can easily be placed into a patient's chart and can thus easily be retrieved.

Fetal Monitoring↗
PubMed1978

Technical aspects of ranged directional doppler: a new doppler method of fetal heart rate monitoring.

A new technique for clarifying the fetal heart Doppler signal (Ranged Directional Doppler) for fetal heart rate (FHR) monitoring has been developed. Ranged Directional Doppler enhances the signals of interest and, in addition, permits a separation of the Doppler signals generated by fast-moving structures of the fetal heart either toward or away from the transducer. The separation of the Doppler signals provides increased clarity and reduced baseline clutter. These Doppler signals may approach the fetal scalp ECG in signal-to-noise ratio, and they may provide a signal that allows more accurate external monitoring of long-term and short-term variability patterns of the FHR.

Doppler Effect↗