Search PubMed⌕ Search

Biomedical subjects

M Solca

Publications and source records attributed to M Solca.

At least 37 records · Page 2Linked to original sources

[Prevention of acute neonatal respiratory insufficiency. A method of conditioning the baboon lung during cesarean section].

Preterm baboons at 140 +/- 3 day gestation (term 182 +/- 7 days) have been subjected to lung conditioning, consisting of a series of prolonged inflations of the lungs at 35 cm H2O, followed by approximately 10 min of application of continuous positive airway pressure (CPAP) equal to 15-20 cm H2O, before umbilical cord interruption. The aim of this study was to evaluate, in a primate experimental model, the safety and efficacy in the prevention of neonatal RDS of a technique so far experimented on only in ovine models. Thoraco-pulmonary compliance exceeded the value of 0.2 ml (cm H2O)-1.kg-1 in only 1 animal out of 5 (20%), which didn't develop illness, versus 69% of positive results achieved with the same technique in lambs at 128-130 day gestation, an experimental model considered in the literature as equivalent to a 140 +/- 3 day gestation baboon as far as it concerns incidence and severity of RDS. The application of lung conditioning was easy and safe (as previously reported), but its effectiveness in a primate model is still to be defined.

Animals↗

A new active model lung.

A new model lung with the capacity for simulated spontaneous breathing is described. It consists of a modified commercial mechanical ventilator (Kontron ABT 4100), connected in parallel to a compliant system, a cylindric acrylic box with a latex thin membrane substituting for the top. Volume and compliance of the model are 2500 ml and 50 ml cmH2O-1, respectively. The modified ventilator simulates physiologic inspiratory flow at a rate of 10 to 30 min-1 and tidal volume up to 1000 ml, with an inspiratory to expiratory time ratio continuously variable between 1:4 and 4:1. The model has been tested under different respiratory assist techniques, connected either to continuous positive airway pressure proved to be reliable, versatile and bearing satisfactory resemblance to human ventilatory physiology.

Humans↗

Enhancement of lung conditioning by acetylcholine in the prevention of respiratory distress syndrome in the preterm fetal lamb.

We exposed 128- to 130-day-gestation fetal lambs by cesarean section leaving the umbilical cord and placenta undisturbed, and we then treated the lungs with pulmonary conditioning (i.e., repeated prolonged inflations to 35 cm H2O, followed by a continuous positive airway pressure of 15 cm H2O). To investigate the added effect of pulmonary vasodilation upon the increase of total compliance and pulmonary oxygen uptake, we also administered acetylcholine intravenously at a rate of 80 micrograms min-1. Eleven of 13 lambs met the endpoint criteria of either compliance (0.5 ml [cm H2O]-1 kg-1; 1 animal), or pulmonary oxygen uptake (6 ml kg-1 min-1; 6 animals), or both (4 animals), and were delivered within 0.6 +/- 0.3 h. This time was significantly (p less than 0.05) shorter than previously seen in similar studies without the infusion of a vasodilator; all animals so delivered survived 24 h of mechanical ventilation in excellent health. We suggest that pharmacologic pulmonary vasodilation, in addition to deep sustained pulmonary insufflation and distension, is an effective and rapid means of transforming stiff immature lungs into lungs that can sustain normal ventilation and gas exchange.

Acetylcholine↗

ECMO revisited.

Explore the source record for details and available documents.

Humans↗

Main nitrogen balance determinants in malnourished patients.

Factors influencing nitrogen balance during total parenteral nutrition have been investigated in 38 malnourished patients studied for a cumulative period of 280 days. According to multiple regression analysis, nitrogen intake (0.213 +/- 0.004 g kg-1 day-1, mean +/- SD) proved to be the major determinant of a positive nitrogen balance (0.018 +/- 0.004 g kg-1 day-1), followed by non-protein energy intake (43.3 +/- 0.5 kcal kg-1 day-1). Total calorie intake to predicted basal energy expenditure and non protein calorie to nitrogen ratios appeared to have little significance on nitrogen balance, when corrected for the two former variables.

Female↗

The main determinants of nitrogen balance during total parenteral nutrition in critically ill injured patients.

Factors influencing nitrogen balance during total parenteral nutrition have been investigated in 34 critically ill injured patients studied during the first 6 days after trauma. Basal nitrogen balance was severely negative (-0.26 +/- 0.12 (SD) g X kg-1), but improved consistently during treatment. Nitrogen intake proved to be the major determinant of a positive, or less negative, nitrogen balance, only secondarily followed by total energy intake corrected to predicted basal energy expenditure, according to multiple regression analysis. The amount of non-protein calories and the non-protein calorie to nitrogen ratio appeared to have little significance on nitrogen balance, when corrected for the two former variables.

Adolescent↗

Respiratory distress syndrome in immature lambs. Prevention through antenatal accelerated conditioning of the lung.

We tested the effectiveness of constant distending pressure applied to immature lungs in preventing respiratory distress syndrome. Fetal lambs of 131 to 134 days gestation were delivered by cesarean section, but the umbilical circulation was kept intact for CO2 removal through the natural in situ placenta. The lungs were inflated to a pressure of 35 cm H2O (Group I, 11 animals) or 25 cm H2O (Group II, 14 animals), after which the airway pressure was maintained at 15 cm H2O through apneic oxygenation until total static compliance exceeded 0.5 ml (cm H2O)- 1kg -1. After a mean of 1.1 and 5.7 h, respectively, the animals were delivered and were given mechanical ventilation for 24 h. Twenty-four animals reached this aimed-for compliance and survived the period of mechanical ventilation in excellent health. A control group of fetal lambs was delivered immediately and treated with mechanical ventilation. Three of 10 control animals developed severe respiratory distress syndrome and died; 1 additional animal survived but with central nervous system involvement from severe hypoxia. We conclude that pulmonary inflation to 35 cm H2O pressure, followed by a constant distending pressure of 15 cm H2O, held until compliance reaches 0.5 ml (cm H2O)- 1kg -1, is an important element in the prevention of respiratory distress syndrome.

Animals↗

Management of the antenatal preterm fetal lung in the prevention of respiratory distress syndrome in lambs.

We have explored change in pulmonary compliance before, and after, repeated deep insufflation of the lungs to a pressure of 35 cm H2O, in 130-days gestation fetal lambs delivered by cesarean section, and while still connected to the intact umbilical cord and the ewe. As a group, all 15 out of 28 fetal lambs that had a rise in total compliance to above 0.2 ml (cm H2O)-1 kg-1 after the first inflation, tolerated 24 h of mechanical ventilation with excellent health and good lung function; only 3 animals out of 13 that showed no similar initial rise in compliance after the first inflation, ultimately survived. We believe the first deep insufflation is an important therapeutic intervention and a useful index to rapidly assess chance of survival in a high-risk fetal lamb population.

Animals↗

Protein sparing and protein replacement in acutely injured patients during TPN with and without amino acid supply.

The metabolic effects of TPN were studied in a selected group of trauma patients. Nineteen patients were randomly divided into two groups: the first was treated with glucose and insulin, the second with glucose, insulin and amino acids. Each patient in both groups received TPN isocaloric with respect to daily energy output and the treatment lasted five days. Each group was further divided into two subsets (severe or moderate catabolism) according to fasting energy output with respect to the expected energy expenditure. During the acute flow phase, both in moderate as well as in severe catabolism, glucose and insulin were effective for protein sparing; the maximum protein sparing effect was reached when giving a caloric intake equal to 130% of daily energy output. Glucose, insulin and amino acids were effective in replacement of nitrogen losses. In moderately catabolic patients nitrogen balance was significantly better than in severely catabolic patients. This study shows that early and short-term TPN is effective in controlling the flow phase of trauma. Glucose and insulin appear to be the determinants of the protein sparing effect when given in amounts equal to those needed; amino acids provided protein replacement when given in amounts equal to about 20% of energy output. Energy supply higher than 120-130% of daily energy output does not increase protein sparing and protein replacement, the only effect being a further increase in metabolism, which is possibly dangerous in critically ill patients.

Adolescent↗

[Changes in the parameters of humoral immunity due to surgical operations or trauma].

Humoral immunity (immunoglobulins and C3) as well as nutritional conditions (serum albumin, transferrin) have been investigated in 23 patients in the acute phase after surgery and/or trauma. Immunoglobulin deficiency, well correlated with the severity of trauma, was observed in the most critically ill patients in the very early phase, followed by a rapid rise to near to normal values and typical immunologic response. There is no evidence that this depression of humoral immunity may enhance the risk of infectious complications in the postoperative period. Very different immunological patterns were observed in surgical patients with chronic sepsis.

Antibody Formation↗

The prevention of hyaline membrane disease (HMD) in the preterm fetal lamb through the static inflation of the lungs: the conditioning of the fetal lungs.

Preterm fetal lambs of a gestational are highly susceptible to hyaline membrane disease were placed on apneic oxygenation while keeping the umbilical circulation intact and still connected to the mother ewe for the removal of metabolically produced CO2. After 4-6 hrs the total lung compliance and the chest x-ray films had markedly improved, allowing normal pulmonary ventilation with a mechanical ventilator. Fetuses older than 135 days gestation were later extubated and allowed to breathe room air unassisted. Fetuses 134 days gestation and younger were kept on mechanical ventilation. None of the animals so treated developed hyaline membrane disease. We believe pulmonary conditioning is an important tool in the prevention and the treatment of hyaline membrane disease. In this animal model we have shown that hyaline membrane disease is a preventable and curable disease.

Animals↗