Ventilatory drive and respiratory muscle function in pregnancy

It has been demonstrated that during pregnancy expiratory reserve volume (ERV) decreases and minute ventilation (VE) increases initially and then stabilizes. In order to determine the role of thoracoabdominal mechanics, control of breathing, and inspiratory muscle function in these alterations, we studied inspiratory pressures, lung volumes, thoracic configuration, and respiratory drive in 18 normal pregnant women at Weeks 13, 21, 30, and 37 of pregnancy. Ten of them were studied 6 months after delivery. Transdiaphragmatic pressure (Pdi) was measured at Week 37 and 3 months after delivery in an additional group of seven women. VE as well as VT/TI increased early during gestation and remained unchanged thereafter. In contrast, mouth occlusion pressure (P0.1) increased progressively during pregnancy, from 1.53 +/- 0.16 (mean +/- SE) to 2.02 +/- 0.18 cm H2O, and fell significantly to 1.1 +/- 0.15 cm H2O after delivery, indicating that effective respiratory impedance increases during pregnancy. Mean P0.1 correlated with progesterone plasma levels (r = 0.918 p less than 0.05). No changes in Plmax, PEmax, and Pdimax, were observed. End-expiratory gastric pressure (Pga) increases significantly during pregnancy: 11.8 +/- 0.8 versus 8.4 +/- 1.12 cm H2O after delivery (p less than 0.012). This increment was correlated with the fall in ERV observed in late pregnancy (r = 0.74 p less than 0.05). Our results demonstrate that during pregnancy ventilatory drive and respiratory impedance increase with the consequent stabilization of VE, but our data do not permit us to differentiate whether the increment in P0.1 is secondary to the increase in impedance or to the rise in progesterone. Respiratory muscle function remains normal despite the alteration of thoracic configuration.

[Alcohol and the risk factors of coronary cardiopathy. A study in 571 men]

In 571 healthy professional males we correlated alcohol consumption with serum total cholesterol (C), HDL-C, triglycerides, blood sugar, cigarette consumption, body mass index and arterial blood pressure. An outstanding finding was a positive independent, correlation of alcohol consumption and serum HDL-C levels (r 0.22, p < 0.0001). Univariate analysis showed correlation of alcohol consumption with body mass index, blood pressure and total serum C, however this was dependent on age and/or body mass. No correlation was found between alcohol consumption and blood sugar or TG levels. Alcohol consumption did not identify a group of subjects with high risk factors. Consumption of more than 10 cigarettes per day decreased the strength of the association between elevated HDL levels and alcohol consumption. We conclude that a moderate intake of alcohol is associated to increased serum HDL levels with no significant change of other coronary risk factors.

[Application of a physiologic stability index at a pediatric intensive care unit]

This study was conducted to evaluate usefulness of the physiologic stability index (PSI) in a pediatric intensive care Unit (PICU) of a University based hospital at Santiago, Chile. Subjects include all patients (n = 152) consecutively admitted to our PICU between april 1987 and august 1988. The PSI system was applied during the first four days from admission. The age of the patients ranged from 10 days to 15 years. Scores obtained from survivors and non survivors were compared using an analysis of variance. For maximum PSI, survivors had significantly lower scores (9.39 points) that non survivors (21.71 points). Multiple logistic regression was used to display associations between mean obtained scores and probability of death and a curve was plotted which is similar to that obtained in previous experiences from other countries.