Search PubMed⌕ Search

Biomedical subjects

F C Miller

Publications and source records attributed to F C Miller.

At least 55 records · Page 3Linked to original sources
PubMed1981

Composting process control based on interaction between microbial heat output and temperature.

Rational composting process control involves the interrelated factors of heat output, temperature, ventilation, and water removal. The heat is released microbially at the expense of organic material; temperature is an effect and, because it is a determinant of microbial activity, it is also a cause of heat output; ventilation supplies oxygen and removes heat, mainly through the vaporization of water; water removal results from heat removal. These relationships were implemented in a field-scale process of static-pile configuration, using a mixture of sewage sludge and wood chips. Heat removal was matched to heat output through a temperature feedback control system, thereby maintaining biologically favorable temperatures. The observations indicate that fundamentally there are two kinds of composting systems: those that are and those that are not temperature self-limiting. The self-limiting system reaches inhibitive temperatures (>60 degrees C) which debilitate the microbial community, suppressing decomposition, heat output, and water removal. In contrast, non-self-limiting temperatures (<60 degrees C) support a robust community, promoting decomposition, heat output, and water removal.

Journal Article↗
PubMed1981

Spacing the injection interval with paracervical block: a randomized study.

To test the hypothesis that spacing the injection interval by 10 minutes would reduce the incidence of post-paracervical block bradycardia, 42 healthy subjects at low risk with normal fetal heart rate (FHR) patterns were included in a randomized trial. Twenty patients were given a conventional paracervical block (ie, almost simultaneous injection of the 2 sides), whereas 22 patients were given the second injection after a 10-minute interval. All patients were laterally positioned for 30 minutes before and 60 minutes after administration of the paracervical block. There were no cases of post-paracervical block bradycardia in either group, but a decrease in the baseline FHR of 5 beats per minute or more occurred in one half of each group. Both groups experienced significant decreases in the mean FHR. The authors conclude that patient selection and perhaps lateral positioning are more important than is spacing the injection interval. Furthermore, in properly selected subjects paracervical block offers simple, effective, and safe analgesia.

Adult↗
PubMed1981

Fetal heart rate changes after accidental intrauterine lidocaine.

Fetal heart rate (FHR) decelerations resembling post-paracervical block (PCB) bradycardia were observed immediately after the inadvertent intrauterine injection of lidocaine hydrochloride. A review of the pathophysiology of post-PCB bradycardia is presented. The administration of a local anesthetic, either into the paracervical tissues or directly into the uterine cavity, may precipitate FHR decelerations principally, through arterial vasoconstriction with subsequent reflex responses and/or hypoxia in the fetus.

Adult↗
PubMed1980

Hemodynamic observations in evacuation of molar pregnancy.

The high incidence of pulmonary complications following evacuation of molar gestation at 16 weeks' size of greater (27%) prompted us to institute hemodynamic monitoring in seven of these patients in an effort to determine etiologies and possible modes of therapy for this potentially life-threatening complication. Our data indicate that following suction curettage with general anesthesia there appears to be impairment of ventricular performance of a transient nature as manifested by increases in central venous pressure, mean pulmonary artery pressure, and pulmonary capillary wedge pressure, despite a slight elevation in cardiac index and a decrease in systemic vascular resistance. The possible role of general anesthesia in the development of these changes, as well as the role of the colloid osmotic pressure to wedge gradient in the development of pulmonary complications, is discussed.

Adolescent↗
PubMed1980

Hemodynamic observations in severe pre-eclampsia with a flow-directed pulmonary artery catheter.

Ten patients with severe pre-eclampsia were studied throughout labor and delivery and during the early puerperium with a flow-directed pulmonary artery catheter. Cardiac output was higher than previously described in normal patients. Pulmonary artery pressures were not significantly altered from the normal pregnant values. The usual increase in cardiac output occurring in the early puerperium was not observed in the patients with severe pre-eclampsia. Central venous pressure and pulmonary artery wedge pressure did not correlate in three of the nine patients studied. Left ventricular stroke work index was elevated in the patients with severe pre-eclampsia, suggesting a hyperdynamic state. The pulmonary artery catheter provided important new information in patients with severe pre-eclampsia and may be a useful clinical adjunct in patients with hemorrhage or oliguria and in patients needing a regional or general anesthetic.

Adolescent↗
PubMed1980

The evaluation of uterine activity. A comparative analysis in 100 primiparous patients.

A comparative analysis has been made of the assessment of uterine activity with the use of both Montevideo units and an automated, on-line method in 100 primiparous patients. The two methods were found to agree well during the active phase of labor. The discrepancies found in both the latent phase and the second stage of labor are discussed. Our assessment is that the automated, on-line method gives a more realistic estimate of the actual uterine work involved in all stages of labor.

Electromyography↗
PubMed1980

Quantitation of uterine activity: clinical evaluation of a new method of data presentation.

An on-line, automated system, voltage-controlled oscillator (VCO), with digital print-out of uterine activity units (UAU) at designated intervals, has been used in clinical studies and appears reliable. A comparison was made between the VCO system and a microprocessor-controlled digital integrator system (MCDI), which displays UAUs as a bar graph every 10 minutes on the uterine activity channel of the clinical fetal monitor.

Data Display↗
PubMed1980

Placenta accreta: changing clinical aspects and outcome.

In an effort to determine if a changing clinical picture for placenta accreta exists in the late 1970s, 22 cases from January 1, 1975, to May 30, 1979, at Los Angeles County/University of Southern California (LAC/USC) Medical Center were reviewed. An incidence of clinically diagnosed placenta accreta of 1 per 2562 deliveries for all cases and 1 per 4027 for pathologically confirmed cases (ie, hysterectomy specimens) was found. Mean age of the patients was 29.5 years, and mean gravidity, parity, and abortion were 3.4, 2, and 0.27, respectively. Placenta previa was found in 14 patients (63.6%), 6 of whom had previously undergone cesarean section. No obvious etiology was found in 1 patient. Sixteen patients underwent cesarean section. Hysterectomy was performed on 14 patients, and conservative measures were employed in 8 patients. One maternal death (4.5%) occurred, but there was no perinatal mortality. The clinical picture of placenta accreta today is one of higher reported incidence, lower parity, greater incidence of associated placenta previa, individualized management, and decreasing maternal and perinatal mortality.

Adolescent↗
PubMed1980

Systolic time intervals in the nonasphyxiated fetus.

The preejection period (PEP) of the cardiac cycle of nonasphyxiated fetuses was evaluated to determine the range of normal to be expected during labor. Standard techniques using the filtered Doppler cardiogram and internally obtained fetal electrocardiogram (ECG) were used. It was demonstrated that the PEP is correlated, although poorly, with heart rate. There is no correlation with fetal weight. The variance from fetus to fetus is quite large. It is concluded that a single measurement of PEP may not be helpful in the determination of fetal hypoxia, since the range of normal varies widely.

Body Weight↗
PubMed1980

Urinary bladder distention: effect on labor and uterine activity.

To study quantitatively the effect of urinary bladder distention on labor and uterine activity, 68 patients requiring catheterization were studied. All patients were in the active phase of labor and had transcervical intrauterine pressure monitoring. Patients were studied in the same lateral position for 30 minutes before and after a catheterization interval, during which time uterine activity units were quantitated on line and changes were noted in cervical dilation and station and contraction frequency and tonus. Results were analyzed for the entire study group, for individual patients, and by urine volumes (10 to 550 ml) obtained at catheterization. Total uterine activity units increased in 43 patients and decreased in 25 after catheterization, but when compared with expected increases calculated from the slopes of the precatheterization interval in individual patients, there were 36 increases and 32 decreases. Individual slopes of uterine activity increased in 36 and decreased in 31 cases. There were no differences when the data were analyzed by urine volume, parity, or bith weight except possibly at large volumes. Changes in rates of cervical dilation and descent of the presenting part conform to the expected normal labor pattern. Within the limits of this study, emptying the urinary bladder has no effect on the course of labor or uterine activity based on the dynamic model of labor.

Adolescent↗
PubMed1979

The evaluation of uterine activity: a comparative analysis.

In this study a comparison is made between the most widely accepted method of expressing uterine activity, Montevideo units, and an automated on-line method expressed as uterine activity units. Although the actual numerical expression differs, the percentage of variation when the two values are compared is small at various phases of labor. The variation between the methods for uterine activity required to progress from 4 to 6 cm cervical dilatation and from 6 to 10 cm cervical dilatation is less than 5%. Both methods closely agree on the actual expression of uterine activity or uterine work.

Amniotic Fluid↗
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

The bupivacaine paracervical block in labor and its effect on quantitative uterine activity.

This study utilized internal fetal monitoring and an on-line voltage control oscillator for measurement of uterine activity unit (UAU) determination in patients who received a paracervical block (PCB) with the use of bupivacaine hydrochloride (Marcaine). The total dose of 25 mg (5 cc/side) of 0.25% bupivacaine used for PCB in 32 patients produced no ill effects to the fetus, as reflected by baseline fetal heart rate (FHR), beat-to-beat variablity, or Apgar scores. No adverse maternal effects were noted, and anesthesia was rated good or excellent in 81% of patients. Rate of cervical dilation remained the same or increased in 29 of 32 patients. Quantitative UAUs showed a significant decrease in the third 10-minute interval after block in primiparas, but no significant change in multiparas or in the group taken as a whole. Total UAUs before versus after PCB for either group or taken together were not statistically different. A decreasing trend in UAUs after PCB versus a positive regression line from activity prior to the block was noted.

Anesthesia, Local↗