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Biomedical subjects

H Lagercrantz

Publications and source records attributed to H Lagercrantz.

At least 181 records · Page 10Linked to original sources
PubMed1984

Catecholamine surge and metabolic adaptation in the newborn after vaginal delivery and caesarean section.

The immediate postnatal metabolic adaptation and sympatho-adrenal activation were studied in infants delivered vaginally or by elective caesarean section. Vaginally delivered infants showed high catecholamine levels at birth compared to infants born by caesarean section under epidural or general anaesthesia. Umbilical arterial glucose levels were significantly higher in the vaginal group than in both caesarean section groups. At 30 min, all groups showed a marked decrease with several infants showing asymptomatic hypoglycaemia in the caesarean section group. C-peptide levels showed no difference at birth but later became significantly higher in the vaginal group. Although the levels of free fatty acids and glycerol were low at birth, they were significantly higher in the vaginal group. In all groups they increased substantially with time. Considering the marked differences in catecholamine levels, the differences in metabolic adaptation were unexpectedly small. This implies an attenuated metabolic response to sympatho-adrenal stimulation in the newborn.

Adaptation, Physiological↗
PubMed1984

Sympatho-adrenal activity and metabolic adjustment during the first 12 hours after birth in infants of diabetic mothers.

Plasma adrenaline and noradrenaline concentrations at birth were the same in infants of diabetic mothers and controls after both vaginal and abdominal delivery. The infants delivered vaginally had significantly higher noradrenaline concentrations than those delivered by caesarean section. During the first 12 postnatal hours, the concentration of noradrenaline decreased to levels similar to those found in newborn infants with minor respiratory problems. No hypoglycemic values were recorded in infants of diabetic mothers at birth nor during the first twelve hours after birth. The C-peptide concentrations at birth were significantly lower in infants of diabetic mothers delivered vaginally as compared to those delivered by caesarean section. The FFA concentrations increased after birth possibly as a result of the lipolytic action of catecholamines released during labour and delivery. We have not been able to confirm the increased sympatho-adrenal activity previously reported in infants of diabetic mothers. We suggest that the difference is due to better metabolic control in the diabetic mothers during pregnancy and delivery in this study.

Adaptation, Physiological↗
PubMed1984

Adenosine analogues depress ventilation in rabbit neonates. Theophylline stimulation of respiration via adenosine receptors?

The effect of the adenosine analogue L-N-phenyl-isopropyl-adenosine (L-PIA) and theophylline on the respiration of rabbit pups was studied. L-PIA (5 mumol/kg) administered intraperitoneally caused a marked respiratory depression in urethane-anaesthetized decerebrate pups and unanaesthetized intact animals during natural sleep. The effect could often be reversed with theophylline. When L-PIA was given after theophylline (20 mg/kg), the effect of L-PIA was considerably lower. L-PIA also caused respiratory depression when administered onto the exposed surface of the fourth ventricle. The effect of the adenosine analogue was more pronounced in younger than in older animals. We conclude that adenosine strongly inhibits respiration and that effect is antagonized by theophylline. The hypothesis is put forward that the therapeutic effect of theophylline on neonatal apnea might be exerted via adenosine antagonism rather than via inhibition of phosphodiesterase. Apnea in infants is often triggered by hypoxemia. It is possible that adenosine, which is released during hypoxia, mediates this effect.

Adenosine↗
PubMed1984

Causes and consequences of maternal and fetal sympathoadrenal activation during parturition.

The sympathoadrenal system is activated in both the mother and fetus during parturition. The fetal plasma catecholamines may reach extremely high levels during deliveries complicated by asphyxia. Increased maternal sympathoadrenal activity during labour or caesarean section may negatively affect uteroplacental blood flow with possible adverse effects on the fetus. Such an increase may be avoided by adequate maternal pain relief and by the sympathetic blockade which follows epidural anaesthesia. Fetal sympathoadrenal activation during parturition seems on the contrary to be of positive functional importance both for fetal circulatory regulation in utero a well as for the neonatal adaptation in terms of pulmonary function and metabolic stimulation.

Adrenal Glands↗
PubMed1984

Classical and 'new' neurotransmitters during development--some examples from control of respiration.

Classical and 'new' neurotransmitters appear in a certain sequence which seem to be similar in rat and man. Serotonin is one of the earliest transmitter which can be detected at a gestational age of 8 days in the rat. A couple of days later noradrenergic and dopaminergic fluorescence can be detected. The development of neurons with gamma-aminobutyric acid and acetylcholine lags behind the monoaminergic neurons. Endorphin is found in high concentrations at an early stage, while substance P, enkephalin and hypothalamic peptides like thyrotropin releasing hormone appear later in development. Inhibitory transmitters like GABA, somatostatin and endorphins reach their maximal concentrations in CNS during infancy, which might have some functional implications. The classical neurotransmitter noradrenaline might have certain unique functions during fetal and perinatal life. It seems to be important for the development of the cerebral cortex. It is released in high quantities at birth and might be of importance for the neonatal adaptation such as inducing arousal. The function of all the newly detected neuropeptides is far from elucidated even in adult life. Some of them seem to have important functions during perinatal life, while perhaps they occur in the adult organism only as evolutionary residues. For example endorphins seem to affect respiratory control in the fetus and the newborn in ways not seen in the adult. So called neuromodulators, for example adenosine, might also have particular functions during perinatal life.

Adenosine↗
PubMed1983

Fetal scalp catecholamines during labor.

Samples of scalp blood were collected from 129 fetuses during the first stage of labor for analysis of plasma norepinephrine and epinephrine concentrations by high-performance liquid chromatography. The catecholamine levels were related to scalp blood pH and fetal heart rate patterns during the 20-minute period preceding the collection of scalp blood. The median norepinephrine level was 9.2 nmol/L (range, 1.3 to 99.7), and the median epinephrine level was 0.5 nmol/L (range, less than 0.5 to 19.2) (n = 111) during the first stage of labor when the pH was above 7.25. The norepinephrine level was considerably higher than that in the resting adult. Significantly higher concentrations of catecholamines were found when scalp blood pH was below 7.26 (p less than 0.001). Maternal analgesia did not influence the fetal catecholamine levels in uncomplicated labor. Significantly higher concentrations of norepinephrine were found during the appearance of abnormal fetal heart rate patterns.

Analgesics↗
PubMed1983

Fetal plasma catecholamine concentrations and fetal heart-rate variability during first stage of labour.

Fetal heart-rate (FHR) variability was studied in 50 term fetuses during the first stage of labour. The variability was computed as an arbitrary index during a 20-min period preceding a fetal scalp blood sample which was used for the measurement of pH, adrenaline and noradrenaline. None of the fetuses was found to have a scalp blood pH less than 7.2. The short-term variability index was significantly correlated with the noradrenaline concentration in fetal blood, but the adrenaline levels which were generally very low showed no correlation with the variability values. There was no correlation between variability index and cervical dilatation or blood pH. We have shown previously high plasma catecholamine concentrations in the asphyxiated fetus with a decreased pH. In this study where fetal pH was normal a correlation between FHR variability and fetal scalp plasma noradrenaline levels was found. Thus an increased FHR variability might be an early sign of fetal distress when fetal pH is still normal.

Analgesics↗
PubMed1983

Catecholamine surge and lung function after delivery.

Lung function was measured at 30 minutes and again at 2 hours after birth in 12 infants delivered vaginally, in 15 infants delivered by elective caesarean section under general anaesthesia (GA), and in 15 delivered under epidural anesthesia (EDA). Umbilical arterial blood was analysed for pH and for concentrations of catecholamines and cortisol. No important differences in gestational age, birthweight, Apgar scores, or haematocrit were found among the three groups. Tidal volume and minute ventilation measured 30 minutes after birth were lower in infants delivered by caesarean section than in those delivered vaginally and at 2 hours the tidal volume was still lower in the babies delivered by caesarean section than in those delivered vaginally. Dynamic compliance was lower at 30 minutes in the group that had a caesarean section than in the vaginal group, and this difference was significant at two hours. Tidal volume, minute ventilation, and dynamic compliance in the GA and EDA groups did not differ. The catecholamine and cortisol concentrations at birth were higher in the vaginal group than in the group delivered by caesarean section. Two hours after birth there was a significant correlation (r = 0.84) between the catecholamine concentrations of the infants born vaginally and lung compliance. The lower dynamic lung compliance in infants delivered by elective caesarean section might be explained by delayed absorption of liquid in the lung due to lack of catecholamine surge.

Anesthesia, Epidural↗
PubMed1983

Left ventricular systolic time intervals and plasma noradrenaline concentrations during acute hypovolaemia in newborn infants.

Left ventricular systolic time intervals and plasma noradrenaline concentrations were determined in twelve newborn infants during acute moderate hypovolaemia. Rapid withdrawal of 8.5 ml of blood per kg body weight shortened the left ventricular ejection time from 204 to 176 msec (P less than 0.001) and increased the plasma noradrenaline concentration from 3.4 to 4.0 nmol/l (P less than 0.05). Systemic blood pressure was unchanged. It is concluded that even a moderate reduction in blood volume is associated with marked changes in left ventricular dynamics. The shortening of left ventricular ejection time during hypovolaemia probably reflects left ventricular adaptation to decreased volumes and response to increased noradrenaline release.

Blood Transfusion↗
PubMed1982

Fetal and maternal plasma catecholamine levels at elective cesarean section under general or epidural anesthesia versus vaginal delivery.

Fetal and maternal plasma levels of catecholamines were measured at birth in 40 women with normal term pregnancies who underwent elective cesarean section. Twenty women were operated on under general anesthesia, and 20 under epidural anesthesia. For comparison, the same measurements were also made in 10 women who underwent vaginal delivery without signs of intrapartum fetal distress. Maternal venous levels of catecholamines were elevated in all three groups as compared to values in the resting adult. The highest levels were found in the vaginal delivery group (norepinephrine and epinephrine, 3.9 +/- 2.1 and 1.1 +/- 1.0 nmoles/L, respectively), and the lowest in the epidural cesarean section group. Fetal outcomes were similar in all three groups, as judged by Apgar scores and by measurements of umbilical arterial blood gases. In spite of that, neonates delivered vaginally showed a markedly higher sympathoadrenal activation (norepinephrine and epinephrine, 31.8 +/- 24.1 and 5.1 +/- 7.6 nmoles/L, respectively) than those born by elective cesarean section. In the latter group, however, it was found that the type of maternal anesthesia influenced fetal sympathoadrenal activation, since neonatal levels of catecholamines were higher in the epidural section group (norepinephrine and epinephrine, 9.5 +/- 6.4 and 4.0 +/- 4.5 nmoles/L, respectively) than in the general anesthesia group (norepinephrine and epinephrine, 3.2 +/- 2.7 and 1.0 +/- 1.4 nmoles/L, respectively). These results may have a certain clinical relevance since fetal sympathoadrenal activation is thought to promote extrauterine adaptation.

Anesthesia, Epidural↗
PubMed1982

An old problem revisited--hyaline membrane disease and Cesarean section.

The incidence of hyaline membrane disease (HMD) was investigated retrospectively in 159 preterm infants below 35 weeks gestation, weighing less than 2,000 g, and born during the 5-year interval 1975-79. The incidence of HMD was compared between infants delivered by elective Cesarean section, Cesarean section after the onset of labor and by the vaginal route. A significant difference (P less than 0.001) was found in the frequency of HMD dependent on the mode of delivery; 50% of infants delivered by elective Cesarean section developed HMD versus 19.2% in the vaginally delivered group. In infants delivered vaginally premature rupture of membranes (PROM) lowered the incidence of HMD to 5% compared to 32.4% in infants without PROM (P less than 0.01). When infants (less than 2,000 g) delivered vaginally without PROM were compared with those delivered by elective Cesarean section, no difference in HMD-incidence was observed. Out of 43 infants with birthweight above 2,000 g, who developed HMD during the 5-year period the majority had been delivered by elective Cesarean section. The possible effect of fetal stress on lung maturation is discussed.

Birth Weight↗