Effect of mode of delivery on incidence of respiratory distress syndrome

The effect of route of delivery on incidence of respiratory distress syndrome (RDS) has been controversial. While some investigators have reported no difference in RDS rates in infants born by cesarean section as compared to vaginal delivery, others have shown a significant increase in risk for RDS among infants born by cesarean section. Data from the 297 patients comprising the placebo group in the recently completed collaborative study of antenatal steroid therapy in the prevention of neonatal RDS, were analyzed to determine the effect of mode of delivery on RDS. The results indicate that infants born by cesarean section without labor have a higher risk for neonatal RDS than infants born vaginally or by cesarean section after a trial of labor.

Identification of fibrin/fibrinogen in glaucoma filtration surgery wounds

We have localized fibrin/fibrinogen in experimental glaucoma filtration surgery wounds in non-human primates by light and transmission electron microscopy. Fibrin/fibrinogen was abundant two days after surgery, but was virtually undetectable by seven days postoperatively. We have confirmed the identity of fibrin/fibrinogen on the ultrastructural level by immunoelectron microscopy employing antibodies directed against fibrinogen. Fibrin clot formation may play an important role in the wound healing response that causes glaucoma filtration surgery to fail.

Secondary affective disorder in women with somatization disorder

Of 60 women with somatization disorder (SD), 54 (90%) met DSM-III criteria for a major affective episode. This group with secondary affective disorder (SAD) was compared with 29 women who had primary affective disorder (PAD). SAD patients reported significantly more symptoms, more psychiatric admissions, more and longer episodes of depression; more had attempted suicide, and more had made multiple attempts. SAD patients had often been hospitalized and were likely to have been treated with lithium and a variety of antidepressants. Studying relatively homogeneous primary psychiatric diagnoses facilitates the identification of distinctions between SAD and PAD patients.

Religious values, practices and pregnancy outcomes: a comparison of the impact of sect and mainstream Christian affiliation

In this report 6566 women enrolled in the Mater-University of Queensland Study of Pregnancy (MUSP) were separated into three groups; members of religious sects, Christians who attend church frequently and Christians who are infrequent attenders. These three groups, respectively labelled Christian sects, Christian attenders and lukewarm Christians were compared on a number of social background, lifestyle and pregnancy outcome variables. The sect members appeared to have the most favourable health, lifestyles and healthy babies at delivery, though this latter finding appears attributable to specific characteristics of the mother and her lifestyle. On most measures the children of lukewarm Christians appear to manifest the worst health while Christian attenders form a group whose children's health is between that of sect members and lukewarm Christians.

A prospective comparative study of the extended nonstress test and the nipple stimulation contraction stress test

The nonstress test and the nipple stimulation contraction stress test were performed at the Medical College of Georgia and the University of Mississippi Medical Center, with the use of common maternal state protocols, minimum criteria for baseline fetal heart rate reactivity, and follow-up of abnormal test results. At the Medical College of Georgia, 656 patients were studied with nonstress tests used as the primary test, whereas at the University of Mississippi Medical Center, 614 patients were managed with the nipple stimulation contraction stress test used as the primary test. Both populations were comparable in regard to pregnancy complications, gestational age, birth weight, perinatal outcomes, cesarean section rates, and the incidence of positive contraction stress tests. Specificity and positive and negative predictive values were similar for both tests. The extended nonstress test had higher sensitivity but also required significantly longer mean duration of testing. The corrected perinatal mortality rate for a reactive nonstress test or negative nipple stimulation contraction stress test was zero within one week of the last test. We conclude that both tests provide excellent primary methods of fetal surveillance and that the decision to use one test rather than the other should be made on the basis of considerations of cost, convenience, time availability, and the presence of specific test contraindications or pregnancy complications.

Formulating a restraint use policy

When the federal government notified Canadian hospital administrators that several deaths had resulted from improper application of physical restraints, we decided to examine our nursing practice in relation to restraint use. The government communiqué indicated that at any one time, up to 10% of a hospital's patient population may be using some form of restraint. A hospital-wide survey indicated that 13.2% of our patients were managed with physical restraints and that insufficient documentation occurred. This was interpreted as a significant clinical-administrative problem and we recognized the need for a formal policy. Other adult care facilities can benefit from our experience in solving this dilemma.

Food iron and lead absorption in humans

Food iron and lead absorption were measured simultaneously in 28 subjects by extrinsically labeling three consecutive meals with the radioactive tracers, iron 59-sulfate and lead 203-chloride. Absorption was measured directly in all subjects by whole-body counting and indirectly in 15 subjects by assessing subsequent levels of tracer in blood. Iron status of the subjects ranged from iron deficient to replete, thus providing a wide range of iron absorption. Statistically significant positive correlations were obtained between food-iron and lead absorption measured by whole-body counting and also between the tracer levels of iron and lead in the blood. However, the correlation between the absorption of the two elements was not strong, as evidenced by the fact that only 50% of the subjects who hyperabsorbed iron also hyperabsorbed lead.

Early prediction of mortality in patients with acute myocardial infarction: a prospective study of clinical and radionuclide risk factors

To examine the prognostic value of early radionuclide imaging in patients with transmural acute myocardial infarction, 222 patients in Killip class I and II were studied prospectively within 24 hours of the onset of symptoms. The 30-day mortality rate for the entire group was 11% (25 of 222). Univariate analysis indicated that an initial radionuclide left ventricular ejection fraction (EF) of less than 0.30 was associated with the greatest relative risk (RR = 6.6), although the percent of abnormally contracting regions (RR = 3.9) and thallium-201 defect index (RR = 3.3) were also significant risk factors. Stepwise logistic regression indicated that addition of EF resulted in the greatest improvement over the best clinical model (Killip class and chest radiographic findings) for the prediction of 30-day mortality (chi 2 improvement = 12.8, p less than 0.0005). Using the optimal model for prediction of mortality (EF and Killip class), a high-risk group with a 30-day mortality rate of 39% (90-day mortality 47%) and a low-risk group with a 30-day mortality rate of 3% (90-day mortality 4%) was identified. In clinically stable patients with transmural acute myocardial infarction, early assessment of EF in conjunction with clinical evaluation, is a valuable method for early identification of high-risk subsets.

Radioimmunoassay for mitoxantrone, a new antitumor agent

A sensitive and specific radioimmunoassay for mitoxantrone in serum has been developed. The procedure allows direct measurement of mitoxantrone in unextracted serum samples, by using antisera from rabbits immunized with mitoxantrone-BSA antigen. Tritiated mitoxantrone of high specific radioactivity (ca. 15 Ci/mmol) was used as a radio-tracer ligand. The assay allows the detection of as little as 50 pg/ml and the quantitation of 75 pg/ml in 0.5 ml serum samples. Standard curves were linear in the concentration range of 75-2500 pg/ml, at antiserum dilutions of 1:15,000. The assay shows good reproducibility: coefficients of variation of 3-6% were obtained by analyzing five samples/concentration at 75, 100, 250, 500, and 1000 pg/ml. There was no cross reactivity with the major metabolite in human serum, having concentrations of up to 10,000 pg/ml. Serum samples collected at various time intervals from rats dosed intravenously with mitoxantrone (0.5 mg/kg), were analyzed for unchanged mitoxantrone by RIA. The drug concentrations decreased from 32 ng/ml at 0.5 h to 0.45 ng/ml by 24 h after dosing. Mitoxantrone, a dihydroxyanthracenedione derivative (1), is an antitumor agent currently used in clinical trials with very encouraging results, especially in metastatic breast cancer, and low incidence of adverse reactions (2-4). The drug is being administered intravenously at doses up to 14 mg/m2. Preliminary pharmacokinetic studies (to be published separately) indicate rapid distribution, followed by slow clearance rates from the tissues. The sensitivity of the currently available (HPLC) methods (5, 6) is of about 5-20 ng/ml in serum.(ABSTRACT TRUNCATED AT 250 WORDS)

Nifedipine therapy for patients with threatened and acute myocardial infarction: a randomized, double-blind, placebo-controlled comparison

Preliminary clinical and laboratory observations suggest that nifedipine might prevent progression of threatened myocardial infarction by reversing coronary spasm or might limit necrosis during the course of acute myocardial infarction. We screened 3143 patients with ischemic pain of greater than 45 min duration and randomly assigned 105 eligible patients with threatened myocardial infarction and 66 with acute myocardial infarction to receive nifedipine (20 mg orally every 4 hr for 14 days) or placebo plus standard care. Treatment was started 4.6 +/- 0.1 hr after the onset of pain. Infarct size index was calculated by the MB-creatine kinase (CK) method and expressed as CK-geq/m2 +/- SE. The incidence of progression to infarction among patients with threatened myocardial infarction was not significantly altered by nifedipine (36 of 48 [75%] for placebo-treated and 43 of 57 [75%] for nifedipine-treated patients). Furthermore, infarct size index was similar among placebo- and nifedipine-treated patients (16.9 +/- 1.5 MB-CK-geq/m2, n = 65, and 17.0 +/- 1.5 MB-CK-geq/m2, n = 68, respectively) with threatened myocardial infarction who exhibited infarction and for those with acute myocardial infarction. Among the 171 eligible patients randomly assigned to drug or placebo, 6 month mortality did not differ significantly (8.5% for placebo vs 10.1% for nifedipine, NS), but mortality in the 2 weeks after randomization was significantly higher for nifedipine-treated patients (0% for placebo compared with 7.9% for nifedipine, p = .018).(ABSTRACT TRUNCATED AT 250 WORDS)

Nifedipine and conventional therapy for unstable angina pectoris: a randomized, double-blind comparison

To characterize the potential of nifedipine in the therapy of unstable angina pectoris we implemented a blinded, randomly assigned, titrated schedule of conventional therapy (propranolol, if not contraindicated, and isosorbide dinitrate) or nifedipine for 14 days in 126 patients hospitalized in a coronary care unit for ischemic chest pain of less than 45 min duration. There were no significant differences between conventionally and nifedipine-treated patients with regard to (1) the time to relief of pain as judged by life table analysis, (2) the decrease in anginal attacks per 24 hr from day 0 to day 2 (-2.5 +/- 0.4 for conventional therapy vs; -2.8 +/- 0.3 for nifedipine), (3) the decrease in the number of nitroglycerin tablets consumed per 24 hr (-2.0 +/- 0.5 for conventional vs -2.1 +/- 0.4 for nifedipine therapy), (4) the percentage of patients requiring morphine on day 1 (13% for conventional vs 21% for nifedipine therapy), or (5) the percentage of patients who developed infarction (14% in both groups). Among the 27 patients who did not respond to initial conventional (n = 13) or nifedipine therapy (n = 14), five in each group became pain free when the opposite therapy (either nifedipine or conventional therapy) was added. In the subgroup of 67 patients who were receiving propranolol before randomization, addition of nifedipine was more effective in controlling pain than was an increase in conventional therapy (p = .026). In the subgroup of 59 patients not receiving prior propranolol, initiation of conventional therapy produced more rapid pain relief than initiation of nifedipine therapy alone (p less than .001), which tended to increase heart rate. Thus, for the study population as a whole therapy with nifedipine alone was equivalent to conventional therapy for unstable angina, although this overall equivalence may result from a combination of superiority of nifedipine therapy in patients previously receiving beta-blocker therapy and superiority of beta-blocker therapy in patients not previously receiving beta-blockers.

Non-invasive measurement of cardiac output by a single breath constant expiratory technique

A new single breath test has been developed that measures pulmonary blood flow (Qc) and pulmonary tissue volume by using the fact that Qc is proportional to the relationship between the absorption rate of acetylene (C2H2) from the alveolar gas and the rate of change of lung volume during constant expiratory flow. To make these measurements a bag in bottle system with a rolling seal spirometer, a mass spectrometer, and a minicomputer with analogue to digital conversion have been used. Qc was compared with cardiac output measured by the thermodilution technique in 20 patients with cardiac disease; some also had mild chronic obstructive pulmonary disease. The mean (SD) resting Qc for the group was 5.27 (1.22) l/min and the cardiac output measured by thermodilution was 5.30 (1.31) l/min. The mean difference between the two estimations of cardiac output was 0.03 l and the standard deviation of this difference was 0.76 l. The Qc technique was not successful in patients with an FEV1/FVC less than 60%, but seemed to be accurate in those with higher FEV1/FVC values. Correction of Qc for the effect of venous admixture in 14 patients resulted in an average 19% overestimation of cardiac output (6.01 (2.52) l/min v 5.05 (1.64) l/min). It is concluded that cardiac output can be accurately measured in patients with cardiac or mild pulmonary disease. No correction for venous admixture due to ventilation-perfusion mismatch was necessary in these patients, presumably because the large breath used by the technique overcomes most mild ventilation-perfusion maldistribution. These findings, in addition to the non-invasive nature of the technique, suggest potential value for the measurement of cardiac output in various clinical conditions.

Suicide in psychiatric patients: age distribution

In eight years, 21183 San Diego County residents killed themselves. Of these, 52 had been at some time patients of one private psychiatric group. The suicide rate increased with age for the county population but not for the psychiatric patients. This difference was highly significant. Although older people generally are at greater risk for suicide, older psychiatric patients may be more responsive to treatment.

Comparative pharmacokinetics of 14C-piperacillin following intravenous and intraperitoneal administration in pregnant and non-pregnant rats

14C-piperacillin (Pipracil) at a dose level of 1000 mg/kg was administered intravenously or intraperitoneally to pregnant and non-pregnant female rats. Rats were sacrificed at predetermined time intervals, and 14C-piperacillin concentrations determined in serum, amniotic fluid, placenta, and fetus. The piperacillin serum levels in both pregnant and nonpregnant rats following intravenous administration were comparable; however, following intraperitoneal administration, the serum drug levels in the pregnant rats as compared to the nonpregnant rats were lower. The fetal drug levels, however, were higher following intraperitoneal administration than following intravenous administration. The total area under the fetal drug concentration-time curve following intraperitoneal administration was about two times the corresponding area under the curve following intravenous administration. The data indicate that the fetal exposure to piperacillin was greater following intraperitoneal administration.

Pregnancy after renal transplantation

The results of a series of 6 pregnancies (including 1 set of twins) in renal transplant patients are presented with a review of the relevant literature. There were no fetal anomalies or deaths, or episodes of renal compromise or graft rejection. The important complications were hypertension (4), prematurity (4) and fetal growth retardation (2).

Understanding preterm labour: the use of Path Analysis

A retrospective study was performed on 465 spontaneous preterm and 13,949 term births, in order to analyze the sequence of events that culminate in preterm labour. Twenty-one variables were investigated by the mathematical technique of Path Analysis. Nine direct and independent precursors of preterm labour were identified. These were antepartum haemorrhage, poor antenatal attendance, previous delivery of a small baby, multiple pregnancy, proteinuria, grand multiparity, cervical suture, low maternal weight, and a history of bleeding before 20 weeks.

Maternal smoking and respiratory distress syndrome

Infants of 603 patients on whom information about smoking habits during pregnancy was available were studied for incidence respiratory distress syndrome. Among the 360 patients who did not smoke, the incidence of respiratory distress syndrome in the neonate was 15.1%, whereas among patients who smoked, the incidence was 9.1%. We speculate that smoking produces a condition of chronic stress in the fetus which brings about an acceleration of fetal pulmonary maturation.

An immunological study of infection of hamsters with large and small plaque canine distemper viruses

The small plaque virus (SPV), derived from the Onderstepoort strain of canine distemper virus (CDV) does not cause a lethal encephalitis in weanling hamsters. When we immunosuppressed hamsters infected with this virus they developed an acute disease, similar to that produced by the large plaque virus (LPV). Passive transfer of maternal antibody from SPV infected mothers to their offspring was effective in preventing acute disease following LPV infection. Co-infection of animals with both LPV and SPV resulted in increased hamster survival, associated with high titres of serum antibody. Similarly, heat inactivated SPV, present during infection with LPV, increased the survival rate. Heat inactivated LPV did not inhibit acute disease, although hamsters had high titres of neutralizing antibody. A small number of animals developed a delayed or recurring paralysis after immunosuppression, exposure to maternal antibody or co-infection. It would appear that the neurovirulence of CDV for hamsters can be modified by altering the levels of circulating antibody early in infection.