Fetal prolactin levels and respiratory distress syndrome

Prolactin levels were measured by radioimmunoassay in cord blood of infants between 28 and 40 weeks of gestation. Also infants, whose mothers received betamethasone prior to delivery, were examined. Between 33 and 36 weeks, the mean plasma cord prolactin levels in infants who developed RDS were significantly lower than HPRL levels in those infants who did not develop RDS. These findings suggest that betamethasone did not alter HPRL levels and point out the possibility of a role of prolactin in fetal lung maturation.     

Incidence of idiopathic respiratory distress syndrome during the last ten years

In the Port Royal Maternity Hospital, with about 2000 deliveries per year, the incidence of idiopathic respiratory distress syndrome (IRDS) has been studied during the last ten years. Because of the potential hazards of drugs, the attitude of restricting the use of steroids to a few particular cases was adopted. In period I (1968–1969), the incidence of IRDS was 1 per 100 live births. In period II (1972–1973), the incidence dropped to 0.54% of the live births. In period III (1975–1977), the incidence remained at 0.47% of the live births. The difference in frequency between period I and periods II and III is statistically significant (P < 0.01). This diminution appears to be the result of an overall improvement in the pre- and postnatal care of premature infants.The newborns who could have benefited from prenatal glucocorticoid treatment are studied in period III. From 28 to 34 wk of gestational age, 148 infants were born. Seventy-eight (≠50%) did not have any respiratory problems, 54 had mild and transitory distress and 16 (≠10%) had IRDS. In only 7 cases was the time interval between the first signs of premature labor and delivery longer than 24 h. In conclusion, at least 148 neonates would have had prenatal glucocorticoid treatment, in order possibly to avoid 7 cases of IRDS, which would mean hazard for 20 and benefit for 1. A hazardous effect on brain development seems to be the main concern and has to be more fully documented.     

Prevention of respiratory distress syndrome in pregnant diabetic women during labor

In the period between 1973 and 1976, in order to prevent neonatal RDS, 24 insulin-dependent diabetic mothers were given Dexamethason before delivery. The treated group was compared with a control group comprising 26 women of the same gesational age, severity of diabetes and mode of delivery. Neonatal care was similar in both groups. In the group where steroid prophylaxis was applied, decrease of RDS morbidity and mortality was observed. The authors accentuate that Dexamethason given to the mother may have an unfavourable effect on carbohydrate metabolism. Therefore, it is recommended to perform 4-hour determinations of blood sugar, urinary sugar and acetone and accordingly, modification of therapy.     

Mean arterial pressure in concordant and discordant triplets during the first week of life.

OBJECTIVE: To retrospectively determine mean arterial pressure (MAP) for stable concordant and discordant triplets during the first 7 days of life. BACKGROUND: Morbidity and mortality for prematurely born triplets is high, therefore, MAP monitoring during the first day of life is important for their clinical management. MAP reference values for special populations such as triplets have not been published. Recently, we reported that in stable discordant twins MAP values during the first day of life were significantly lower in the smaller than in their larger siblings. Comparable information for triplets is not available. DESIGN: Retrospective cohort study. METHODS: We studied 30 sets of concordant and 29 sets of discordant (birth weight difference > or =20%) consecutively born triplets. Stable patients were defined as those having umbilical cord hemoglobin > or =13 g/dl, normal blood gases, who were never treated for hypotension, and survived at least 7 days. MAP (torr) were measured by oscillometry in 3410, and by transducer via an umbilical arterial catheter in 1251 instances. RESULTS: Concordant and discordant triplets were similar in demographics, history of preterm labor (63 and 63%), chorioamnionitis (10 and 10%), pre-eclampsia (53 and 48%), cesarean delivery (100 and 100%), antenatal steroids (77 and 73%), cord hemoglobin (16 and 16 g/dl), combined triplets birth weight (4922 and 4732 g), gestational age (32 and 33 weeks), normal head ultrasounds or Grade I intracranial hemorrhage (96 and 100%) and neonatal mortality (2 and 1%), but were different in the number of infants requiring mechanical ventilation (57 and 31%). A total of 80 (89%) concordant triplets and 77 (88%) discordant triplets were stable according to our definition. Concordant stable triplets, whether small, medium or large, had similar MAP at birth. Their MAP values increased noticeably from birth to 24 hours and more subtlely to 7 days. Triplets of < or =32 weeks GA had lower MAP throughout than those of > or =33 weeks GA. Discordant stable triplets were divided into 27 small (1382 g), 26 medium (1683 g) and 27 large (1969 g); during the first 24 hours, medium and smaller triplets had MAP values that were lower than those of their larger siblings. From the second to the seventh day of life, all MAP values and trends were similar. Among discordant triplets, 86% of the smallest, 13% of the medium and 13% of the largest infants had asymmetrical intrauterine growth restriction. CONCLUSION: In stable concordant and stable discordant triplets, MAP correlates with birth weight, gestational age and postnatal age. MAP values increase noticeably during the first 24 hours and more subtlely during the next 7 days. Concordant or discordant, small, medium, and large triplets have similar MAP values and trends to that of their siblings. Small and medium discordant triplets have lower MAP values during the first day of life than their larger siblings but by the second day there MAP trends and values were no longer different.     

Prevention of respiratory distress syndrome

RDS continues to be a major problem for premature infants despite a better understanding of its pathophysiology and of ways to try to prevent it. To date, prenatal administration of glucocorticoids has been the most widely used method of accelerating fetal lung development. However, several limitations of this therapy have prompted the search for alternative approaches. Most efforts have focused on the potential use of combined hormonal therapy with glucocorticoids and either thyroid hormones or TRH. The easy transplacental passage of the latter tends to favor its use. The use of hormonal therapy prenatally and surfactant administration at birth appears currently to be the best approach to prevent RDS. The greatest benefit would clearly come from the prevention of prematurity (Fig 1), but this has not proved to be an easy task.     

Adult respiratory distress syndrome in obstetrics

Despite the advances in medical technologies, ARDS is highly lethal. In the management of patients with ARDS, certain clinical conditions are common predisposing factors to the development of the syndrome. Infection, sepsis syndrome, and conditions requiring massive transfusion are the most common causes in patients initially managed by obstetricians and gynecologist. Early recognition of ARDS with timely consultation is of paramount importance in these patients. Early in the course of the illness, the patient should be placed in an intensive care unit. Physicians with experience in the altered pulmonary physiology should be included in the team, as well as infectious disease and renal consultants, as the situation demands. Due to the overall relative youth of our obstetric and gynecologic patients and their lack of other underlying diseases, they should do better than most patients with ARDS. However, at least 50% of all patients succumb to the disease itself or to complications inherent in the care needed. Families and treating physicians should be apprised of this early in the course.     

Adenosine deaminase levels in premature infants with respiratory distress syndrome and bronchopulmonary dysplasia

Adenosine is produced in the inflammed and damaged lung where it plays roles in the regulation of inflammation and tissue remodeling. Adenosine deaminase (ADA) is an enzyme responsible for the degradation of adenosine. Our aim was to compare the levels of ADA between infants with and without respiratory distress syndrome (RDS) and to determine the relationship between plasma ADA levels and bronchopulmonary dysplasia (BPD). One-hundred and twenty-five premature infants who were admitted to our neonatal intensive care unit were included in the study. Eighty-one of these infants with RDS were study group and the other 44 infants without RDS served as controls. Blood collection was made in the first day of life at the end of 24th-h and was used for laboratory testing. In the RDS group, mean ADA level was 25.5 (±4.5) U/l, and in controls it was 26.3 (±5.7) U/l. There was no statistically significant difference (p?=?0.326) in these groups although there was a statistically difference of ADA levels between BPD (34.5?±?5.2 U/l) and non-BPD (24.6?±?4.1) patients (p?=?0.001). There was also a positive relationship between ADA levels and severity of BPD (r?=?+?0.845, p?=?0.01). Perinatal inflammation is the key mechanism of BPD. ADA level in early postnatal life is elevated in infants with BPD and may be related with perinatal inflammation.     

Cord serum lipid and apolipoprotein levels in preterm infants with the neonatal respiratory distress syndrome

Objective: The purpose of this study was to evaluate the effects of birth weight on cord serum lipid and apolipoprotein levels in preterm infants with and without respiratory distress syndrome (RDS). Methods: Cord serum lipid and apolipoprotein levels were evaluated in preterm infants (39 with RDS and 68 controls without RDS). Based on morbidity and mortality risk, RDS and non-RDS infants were separated into four birth weight groups (2000-2499 g, 1500-1999 g, 1000-1499 g, < 1000 g) and evaluated for effects of birth weight on cord serum levels. Results: RDS infants with birth weight of 2000-2499 g had significantly higher levels of cholesterol, triglyceride, total fatty acids and apolipoprotein A-I, but not arachidonic acid, than controls. RDS infants weighing 1000-1999 g had lower total fatty acids and apolipoprotein B levels, including arachidonic acid, than non-RDS infants. Cord serum lipid and apolipoprotein levels were significantly elevated in large (2000-2499 g) RDS infants, but lower levels were found in smaller (1000-1999 g) RDS infants. Conclusions: Cord serum arachidonic acid and apolipoprotein levels found in RDS infants suggest that lipid transport across the placenta may be abnormal. Inadequate total fatty acid supplies in utero could interfere with normal fetal growth and maturation, leading to development of neonatal RDS as one manifestation of risk for postnatal morbidity and mortality.     

Pulmonary surfactant replacement in respiratory distress syndrome

Exogenous surfactant therapy in infants with HMD leads to dramatic improvement in oxygenation and disease course. Both prophylactic and rescue treatments have shown a significant reduction in morbidity and mortality from the disease. There are several questions yet to be answered regarding the most effective surfactant, the appropriate time of treatment, and the appropriate dose, as well as the number of treatments required. Based on the available data, surfactant TA has shown promising and consistent results. Another important question to be answered is the role of surfactant in milder cases of HMD and its impact on the cost of hospitalization. Hopefully, future studies will be able to provide answers to these questions.     

Natural surfactant substitution in respiratory distress syndrome

Natural surfactants consist of unique proteins and lipids. Their effectiveness in improving subnormal lung function in surfactant deficiency should be established prior to any clinical trials. Rigorous tests are required to document batch to batch variability in surface activity and to exclude toxic contaminants. Up to this date randomized clinical trials in small preterm infants have demonstrated a striking improvement in lung function, and a decrease in incidence of acute complications (pneumothorax, interstitial emphysema). Administration of human surfactant at birth or in severe RDS decreased deaths and incidence of bronchopulmonary dysplasia. Although homologous surfactant may not be more advantageous than the heterologous one in terms of its acute beneficial effects on lung function, the safety and efficacy of animal surfactant in improving the outcome remains to be established. Human surfactant may serve as a model for unlimited natural surfactant produced by gene technology. The pharmacodynamics aspects of surfactant substitution, the indications of exogenous surfactant, and the management of the patients undergoing surfactant substitution remain to be studied. Exogenous surfactant offers a potential to treat or prevent severe respiratory failure in infants, children and adults.