morphine and Hypoxia

To use sheep and rat models and demonstrate that stressors activate fetal glucocorticoid (GC) system, corticotrophin-releasing factor (CRF) system and cholinergic neurotransmitter system (ChNS) leading to propulsive colonic motility and in utero meconium passage. Immunohistochemical studies (IHS) were performed to localize GC-Receptors, CRF-receptors and key molecules of ChNS in sheep fetal distal colon. CRF expression in placenta and enteric endocrine cells in fetal rat system were examined and the effects of acute hypoxia on in utero meconium passage was tested. IHS confirmed localization and gestation dependent changes in GC-Rs, CRF-Rs and cholinergic markers in sheep fetal colon. Rat placenta and enteric endocrine cells express CRF and gastrointestinal tract express CRF-Rs. Hypoxia is a potent inducer of meconium passage in term fetal rats. Stress is a risk factor for in utero meconium passage and laboratory animal models can be used to develop pharmacotherapy to prevent stress-induced in utero meconium passage.

Topics: Adrenocorticotropic Hormone; Animals; Disease Models, Animal; Gastrointestinal Motility; Glucocorticoids; Humans; Hypoxia; Meconium; Rats; Risk Factors; Sheep; Stress, Physiological

Topics: Acid-Base Equilibrium; Acidosis; Asphyxia Neonatorum; Blood Circulation; Blood Glucose; Body Temperature Regulation; Calcium; Central Nervous System Diseases; Humans; Hyaline Membrane Disease; Hypoxia; Infant, Newborn; Meconium; Oxygen Consumption; Pneumonia, Aspiration

Topics: Animals; Animals, Newborn; Asphyxia Neonatorum; Birth Order; Carbon Dioxide; Delivery, Obstetric; Environmental Exposure; Female; Fetal Death; Fetus; Humans; Hydrogen-Ion Concentration; Hypoxia; Infant, Newborn; Lactates; Meconium; Obstetric Labor Complications; Oxygen; Pregnancy; Respiration; Stress, Physiological; Swine; Swine Diseases; Temperature; Umbilical Cord

Topics: Acidosis; Amniotic Fluid; Bicarbonates; Birth Weight; Carbon Dioxide; Estriol; Female; Fetal Diseases; Fetal Heart; Fetus; Growth; Heart Rate; Humans; Hydrogen-Ion Concentration; Hypoxia; Labor, Obstetric; Maternal-Fetal Exchange; Meconium; Muscle Contraction; Oxygen; Oxygen Consumption; Oxygen Inhalation Therapy; Oxytocin; Pregnancy; Pregnancy in Diabetics; Scalp; Ultrasonography; Uterus

Topics: Acidosis; Animals; Animals, Newborn; Asphyxia Neonatorum; Bacterial Infections; Cerebral Hemorrhage; Erythroblastosis, Fetal; Female; Fetal Diseases; Hepatitis, Animal; Horse Diseases; Horses; Humans; Hypoglycemia; Hypoxia; Infant, Newborn; Meconium; Nephritis; Pregnancy; Respiratory Insufficiency; Seizures; Syndrome; Virus Diseases

Topics: Amnion; Amniotic Fluid; Color; Endoscopy; Female; Fetal Diseases; Humans; Hypoxia; Meconium; Methods; Postoperative Complications; Pregnancy

Topics: Amniotic Fluid; Asphyxia; Blood Gas Analysis; Cesarean Section; Extraction, Obstetrical; Female; Fetal Diseases; Fetal Heart; Humans; Hypoxia; Infant, Newborn; Labor, Induced; Labor, Obstetric; Maternal-Fetal Exchange; Meconium; Phonocardiography; Pregnancy; Prenatal Care; Umbilical Cord

To study the arginase, nitric oxide synthase and nitric oxide pathways associated with passage of meconium.. Cord blood samples were collected from 20 newborns with meconium-stained amniotic fluid (MSAF) and from 23 newborns with clear amniotic fluid. Cord blood pH, arginase, nitric oxide synthase and nitric oxide levels were compared between the groups.. The differences between the arginase and nitric oxide measurements of the newborns with MSAF and those with clear amniotic fluid were significant. In the MSAF group arginase levels were significantly lower (p=0.007) and nitric oxide levels were significantly higher (p=0.032) than the clear amniotic fluid group.. Hypoxia may be involved in the pathogenesis of meconium passage due to decreased arginase and increased nitric oxide levels.

Topics: Adult; Amniotic Fluid; Arginase; Arginine; Female; Fetal Blood; Humans; Hypoxia; Infant, Newborn; Meconium; Nitric Oxide; Nitric Oxide Synthase; Pregnancy

We previously showed that meconium causes lung cell death by apoptosis and inflammatory cytokine expression. Whether this is due to meconium exposure itself, or meconium related hypoxia remains unclear.. To elucidate the effects of meconium, saline, milk, hypoxia and hyperoxia induced lung injury.. We studied 5 groups of rabbit pups: (I) normal saline; (II) Milk; (III) 10% solution of meconium; (IV) only to 15 minutes of hypoxia (10% O(2)), and (V) 5 minutes of hypoxia (95% O(2)). After exposure lung lavage cells were used for apoptotic cell count and cytokine expression. In vitro response of human A 549 epithelial cells to meconium-and milk exposure was also studied.. There was no difference in cell death between saline and milk groups. However, meconium caused a significant cell loss compared to saline and milk-Inflammatory cytokines increased significantly in meconium group compared to saline or milk group. Although hypoxic and hyperoxic lungs showed increased inflammatory reaction compared to saline-treated lungs, this injury was not significant compared to meconium group. Studies with A549 cells also showed similar results.. We conclude that lung cell injury in meconium aspiration is mainly from meconium itself.

Topics: Animals; Animals, Newborn; Cell Line; Humans; Hypoxia; Infant, Newborn; Inflammation; Lung Injury; Meconium; Meconium Aspiration Syndrome; Milk; Rabbits

Meconium-stained amniotic fluid (MSAF) is thought to be a sign of fetal hypoxia, which causes activation of coagulation and inhibition of fibrinolysis. Inflammation is also seen in MSAF. On the other hand, thrombin activatable fibrinolysis inhibitor (TAFI) is an inhibitor of fibrinolysis and a regulator of vascular inflammation. For this reason, in this study we aimed to evaluate the relation between hypoxia, fibrinolysis, and inflammation by determining the levels of TAFI activity (TAFIa) in MSAF where inflammation was also thought to have a role in the pathogenesis.. The MSAF group consisted of 22 neonates; 20 neonates served as the control group. Plasma TAFIa levels were evaluated in all neonates in the first six hours of life.. TAFIa levels were significantly higher in the MSAF group when compared with the control group and the levels correlated negatively with cord blood pH levels.. Increased TAFIa levels in neonates with MSAF might be due to hypoxia. Inflammation observed in MSAF may also play an additional role in increased TAFIa expression. Although no clinical complication that can be attributed to this increase was seen, one should be alert to the complications of depressed fibrinolysis that might be observed in these neonates.

Topics: Amniotic Fluid; Carboxypeptidase B2; Female; Fetal Blood; Gestational Age; Humans; Hydrogen-Ion Concentration; Hypoxia; Infant, Newborn; Inflammation; Male; Meconium

Intrauterine meconium (MEC) passage and aspiration may result in significant newborn morbidity, though there is little understanding of the physiologic mechanisms for MEC passage. We hypothesized that stress induces fetal MEC passage via corticotrophin releasing factor (CRF), a known mediator of colonic motility in adult rats. Pregnant rats at e22 were subjected to acute hypoxia or normoxia for 35 min, after which rats were anesthetized and fetuses operatively delivered. Amniotic fluid bilirubin and intestinal alkaline phosphatase were measured as markers for MEC passage, and fetal and maternal plasma CRF and corticosterone levels determined. Hypoxic stress induced defecation in all dams and provoked visible MEC passage in all fetuses. Amniotic fluid bilirubin content was significantly higher in hypoxic fetuses versus controls (1.064 +/- 0.101 versus 0.103 +/- 0.003 O.D. at 410 nm) and intestinal alkaline phosphatase was consistently elevated in MEC stained amniotic fluid. Hypoxia significantly increased plasma CRF (maternal, 82 +/- 5 to 196 +/- 14 pg/mL; fetal, 284 +/- 15 to 1523 +/- 185 pg/mL) and corticosterone (maternal, 417 +/- 50 to 1150 +/- 50 ng/mL; fetal, 96 +/- 5 to 182 +/- 10 ng/mL) compared with controls. In view of the known action of CRF in adult colonic motility, these results suggest that hypoxic stress-mediated MEC passage in term fetal rats is mediated by a CRF dependent pathway.

Topics: Animals; Animals, Newborn; Corticotropin-Releasing Hormone; Defecation; Female; Gastrointestinal Motility; Hypoxia; Meconium; Pregnancy; Rats; Rats, Sprague-Dawley; Stress, Physiological; Uterus

Topics: Air; Amniotic Fluid; Animals; Asphyxia Neonatorum; Cardiomyopathies; Contraindications; Disease Susceptibility; Dose-Response Relationship, Drug; Europe; Humans; Hypoxia; Infant, Newborn; Kidney Diseases; Meconium; Models, Animal; Muscle Hypotonia; Neoplasms; Oxygen; Oxygen Inhalation Therapy; Practice Guidelines as Topic; Resuscitation; United States

Our objective was to study meconium-induced lung injury in isolated perfused rat lungs exposed to anoxia. Our working hypothesis was that meconium-induced lung injury is independent of preexisting hypoxia, and that hypoxia will increase severity of lung injury observed after meconium aspiration. We compared five different groups of animals (n = 5) for pulmonary arterial pressure (PAP), weight lung changes, and TNFalpha expression. Group I had lungs instilled with 4 ml of normal saline. Group II had lungs exposed to 5 min of anoxia. Group III had lungs instilled with 4 ml of 30% filtered human meconium. Group IV had lungs exposed to 5 min of anoxia and then instilled with 4 ml of 30% filtered human meconium. Group V had lungs instilled with 4 ml of 30% unfiltered human meconium. Our subjects were adult Sprague-Dawley rats. The isolated rat lung model was prepared according to Levey and Gast (J Appl Physiol 1966;21:313-316). Lungs were ventilated with room air. Anoxia was caused by the use of N(2). The pulmonary artery was cannulated, and pulmonary arterial pressure and lung weight were measured. Lung weight and pulmonary arterial pressure were monitored for 120 min, and TNFalpha levels were measured in effluent at 15, 30, 60, and 120 min. Experiments were done at the Michael Reese Hospital (Chicago, IL). At the end of the experiment, PAP reached its highest values in group V (10.0 +/- 1.7 mmHg). Final PAPs in groups I-IV were: 4.85 +/- 0.3, 4.99 +/- 0.4, 5.93 +/- 0.3, and 7.25 +/- 0.51 mmHg, respectively). Lung wet weight increased significantly only in groups IV and V vs. group I; at 120 min, they were: 0.96 +/- 0.3 g, P < 0.01, and 1.5 g +/- 0.2 g, P < 0.01, respectively. TNFalpha levels did not change significantly over time in group I. TNFalpha is a marker as well as proprietor of pulmonary inflammatory response. TNFalpha reached its highest levels in groups IV and V: 595 and 753 pg/ml at 120 min, respectively. In conclusion, a short episode of anoxia prior to meconium aspiration may increase lung sensitivity to meconium-induced lung injury. This effect may be moderated by the TNFalpha present in the pulmonary circulation.

Topics: Animals; Animals, Newborn; Filtration; Hypertension, Pulmonary; Hypoxia; In Vitro Techniques; Inhalation; Lung Diseases; Meconium; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha

Meconium aspiration induces pulmonary inflammation and reduces surfactant function. We hypothesized that albumin mixed with meconium attenuates pulmonary inflammation and improves surfactant function after meconium aspiration. We measured the concentration of free fatty acids (FFA) in the meconium (110 mg dry weight/mL) and added albumin to provide a molar FFA:albumin ratio of 1:1. Newborn piglets, 0-2 day of age, artificially ventilated and exposed to hypoxemia by ventilation with 8% O2, were randomized to group A receiving meconium (n = 12), or group B receiving meconium + albumin (n = 12), 3 ml/kg intratracheally. The animals were reoxygenated for 8 h. Reoxygenation was started when mean arterial blood pressure was < 20 mm Hg or base excess was < -20 mmol/L. During 8 h of reoxygenation the interleukin-8 concentrations in tracheobronchial aspirates increased 5-fold more in the meconium vs. the meconium + albumin groups (93 +/- 56 vs. 18 +/- 4 pg/mL, p < 0.005). There were no differences between the groups for tumor necrosis factor alpha in tracheobronchial aspirates, recruitment of inflammatory cells in the airspaces or surfactant function in bronchoalveolar lavage fluid. In conclusion, albumin significantly decreased interleukin-8 concentrations in tracheobronchial aspirates after meconium aspiration.

Topics: Animals; Animals, Newborn; Bronchi; Bronchoalveolar Lavage Fluid; Fatty Acids, Nonesterified; Humans; Hypoxia; Infant, Newborn; Interleukin-8; Lung; Meconium; Meconium Aspiration Syndrome; Oxygen; Pulmonary Surfactants; Serum Albumin, Bovine; Surface Tension; Swine; Trachea; Tumor Necrosis Factor-alpha

To understand the pathogenesis of meconium aspiration syndrome, we compared the pulmonary and inflammatory effects of the water and lipid extracts of human meconium instilled into the lungs of newborn piglets. The piglets were artificially ventilated, made hypoxemic, and randomized into three groups. At start of reoxygenation, 3 ml/kg of one of the following mixtures was instilled intratracheally: (1) meconium (n = 12); (2) water extract of meconium (n = 12), and (3) lipid extract of meconium (n = 12). During 8 h of reoxygenation, hemodynamics, pulmonary gas exchange, lung mechanics, and interleukin-8 concentrations in tracheobronchial aspirates were monitored. Oxygenation index (p = 0.04) and mean airway pressure (p = 0.04) increased more in the lipid extract group than in the water extract group. Dynamic compliance and mean arterial blood pressure decreased (p < 0.05) in the meconium and lipid extract groups, but not in the water extract group. At 8 h of reoxygenation, the interleukin-8 concentration in the tracheobronchial aspirates was three times higher in the lipid extract group as compared with the water extract group (110 +/- 102 vs. 37 +/- 27 pg/ml; p = 0.02). In conclusion, pulmonary dysfunction in meconium aspiration syndrome is caused by both the water- and lipid-soluble fractions of meconium, with stronger inflammatory and more detrimental effects promoted by the lipid extract than the water extract.

Topics: Animals; Animals, Newborn; Blood Pressure; Humans; Hypoxia; Infant, Newborn; Inflammation; Interleukin-8; Lipids; Lung; Lung Diseases; Meconium; Meconium Aspiration Syndrome; Oxygen; Pulmonary Gas Exchange; Respiration, Artificial; Solubility; Swine; Tissue Extracts; Vascular Resistance; Water

Since meconium aspiration often induces an inflammatory respiratory disorder, we investigated the effects of intrapulmonary meconium on the expression of cyclooxygenase-1 and 2 in rat lungs. Suspension of human meconium was instilled intratracheally into ventilated lungs of anesthetized rats, while control rats received an equal volume of saline. The meconium lungs were ventilated either with air or 100% oxygen, and control lungs were ventilated with air. After 3 h, the lungs were removed and the amount of cyclooxygenase-1 and 2 mRNA was measured by Northern blot analysis. Cyclooxygenase-1 mRNA was clearly expressed in control rat lungs, while cyclooxygenase-2 expression was minimal. Meconium administration markedly upregulated the expression of cyclooxygenase-2 mRNA, while cyclooxygenase-1 expression remained unchanged. Increased expression of cyclooxygenase-2 was detected in rat lungs ventilated with either air or oxygen. Our data thus indicate that meconium aspiration induces pulmonary expression of cyclooxygenase-2, suggesting an important role for prostaglandins in the meconium aspiration-induced inflammation in neonatal lungs.

Topics: Animals; Cyclooxygenase 1; Cyclooxygenase 2; Gene Expression Regulation; Humans; Hypoxia; Infant, Newborn; Isoenzymes; Lung; Male; Meconium; Membrane Proteins; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Sprague-Dawley; RNA, Messenger

To determine if meconium in the amniotic fluid (AF) can cause cerebral palsy by stimulating umbilical and placental blood vessels to constrict.. Brain injury patterns were analyzed in 43 children whose exposure to meconium in the AF was their only identified risk for quadriplegic cerebral palsy. The times their injuries occurred were established by following lymphocyte counts in their blood after birth.. All 43 had cerebral cortical and subcortical brain damage of the type produced by late gestational ischemia and hypoxemia. The time between the onset of injury and birth ranged from 2-38 hours. The neonates were severely acidotic at birth when birth occurred within 12-14 hours after ischemia and hypoxemia began. Thereafter, the acidosis receded as the time between its start and birth increased, presumably because vasoconstriction had ended. Severe acidosis did not recede in nine children whose cerebral palsy was due to disorders that kept them hypoxemic until birth.. Meconium in the AF may sometimes initiate vasoconstriction that leads to ischemic, hypoxemic cerebral palsy.

Topics: Acidosis; Amniotic Fluid; Brain Ischemia; Cerebral Palsy; Erythroblasts; Erythrocyte Count; Fetal Blood; Fetal Diseases; Humans; Hydrogen-Ion Concentration; Hypoxia; Infant, Newborn; Lymphocyte Count; Meconium; Time Factors; Umbilical Cord; Vasoconstriction

Topics: Body Weight; Brain; Brain Edema; Humans; Hypoxia; Infant; Infant, Newborn; Inhalation; Meconium; Organ Size; Respiration; Spinal Cord

A study was undertaken on 54 cases of meconial aspiration in order to establish a prognostic index allowing the early estimation of the risk of occurrence of refractory hypoxia. In order to do so, the factors statistically related to the occurrence of refractory hypoxia were taken into account. These factors consisted of the first arterial blood gas determination, first chest x-ray film and the initial Silverman index. A value was assigned to each parameter, with respect to the corresponding percentage of observed refractory hypoxias. The sum of the values determined the prognostic index, which varied from 6 to 25. For a high-risk threshold fixed at 15, sensibility was 78%, specificity 90% and the predictive value 84%. For an index between 16 and 20, 70% of patients developed refractory hypoxia. Occurrence was 100% for an index above 20 and refractory hypoxia occurred early. On the contrary with indexes between 6 and 14, occurrence was 15%. The calculation of this index might help clinicians in their therapeutic decisions.

Topics: Apgar Score; Humans; Hypoxia; Infant, Newborn; Meconium; Pneumonia, Aspiration; Prognosis; Respiration, Artificial; Resuscitation

Topics: Diatrizoate; Diatrizoate Meglumine; Enema; Humans; Hypotension; Hypoxia; Infant, Newborn; Intestinal Obstruction; Intraoperative Complications; Male; Meconium; Plasma Volume

The short-term effects of muscle relaxation with pancuronium bromide on arterial blood gas values, heart rate, and arterial blood pressure were studied in 49 neonates receiving mechanical ventilation. After pancuronium administration, mean PaO2 increased from 61.9 +/- 30.0 to 80.9 +/- 52.8 mm Hg (P = 0.006), mean PaCO2 decreased from 40.1 +/- 13.0 to 37.5 +/- 13.3 mm Hg (P = 0.03), and mean heart rate rose from 146.2 +/- 24.9 to 161.0 +/- 20.5 beats/min (P less than 0.001). Arterial blood pressure did not change significantly. When results were analyzed by diagnosis (meconium aspiration syndrome, hyaline membrane disease, pneumonia), only infants with meconium aspiration syndrome had a significant improvement in oxygenation (P = 0.008). Six of 18 patients with hyaline membrane disease responded to muscle relaxation, with a decrease in PaO2 of 10 mm Hg or more. No significant correlation was found between change in PaO2 and birth weight, gestational age, postnatal age, or change in heart rate. A weak correlation (r = -0.37, P less than 0.006) was observed between change in PaO2 and change in PaCO2. Although the reasons for the divergence in response in different groups of patients are not entirely clear, the risk of deterioration with pancuronium therapy should be kept in mind, particularly if treatment in an infant with hyaline membrane disease is being considered.

Topics: Blood Gas Analysis; Blood Pressure; Heart Rate; Humans; Hyaline Membrane Disease; Hypoxia; Infant, Newborn; Meconium; Pancuronium; Pneumonia; Pneumonia, Aspiration; Respiration, Artificial

MAS can be divided into 2 stages, distinguishable with respect to morphology of the lungs, clinical symptoms and laboratory data. The reason for the vasoconstriction of the pulmonary vascular bed typical for stage 2 is not yet fully understood. It seems, however, plausible that meconium contains substances (enzymes?) which may trigger the release or the synthesis of vasoactive compounds during the process of an aseptic inflammation. Cleaning the upper respiratory tract of an infant with meconium in the amniotic fluid immediately after birth is the most effective step in the prevention of MAS. This measure has led to a dramatic decline in both morbitity and mortality of the disease. In rare instances rinsing of the trachea with saline can help to remove considerable amounts of meconium too thick and sticky to be removed by simple suction.

Topics: Airway Obstruction; Animals; Humans; Hypoxia; Infant, Newborn; Infant, Newborn, Diseases; Inhalation; Lung; Meconium; Mediastinal Emphysema; Partial Pressure; Pneumothorax; Pulmonary Emphysema; Rabbits; Radiography; Respiration; Respiration, Artificial; Syndrome; Therapeutic Irrigation

Severe hypoxia unresponsive to maximum ventilatory support occurs both in idiopathic respiratory distress syndrome and meconium aspiration. We recently encountered a 980 g female infant with respiratory distress syndrome and 3 300 g female infant with meconium aspiration and persistant fetal circulation whose clinical course necessitated the use of tolazoline and dopamine to reduce pulmonary and to stabilize systemic pressures. The infant with respiratory distress syndrome responded with a PaO2 increase of 2.7 kPa while the infant with persistant fetal circulation and meconium aspiration showed a 51.6 kPa rise. Combined pharmacologic therapy may have a role in improving oxygenation status in severely hypoxemic infants receiving maximum support.

Topics: Dopamine; Female; Humans; Hypoxia; Infant, Newborn; Infant, Newborn, Diseases; Infant, Premature, Diseases; Lung; Meconium; Pneumonia, Aspiration; Respiratory Distress Syndrome, Newborn; Tolazoline; Vascular Resistance; Vasoconstriction

Topics: Amniotic Fluid; Chromatography, High Pressure Liquid; Female; Fetal Death; Fetal Distress; Humans; Hypoxanthines; Hypoxia; Infant, Newborn; Inosine; Meconium; Pregnancy; Purines; Xanthines

Three patients with Meconium Aspiration Syndrome (S.A.M.) and severe hypoxemia are reported. From the first hours of life they needed mechanical ventilation, showing no improvement in PaO2 in spite of usual respiratory support measures. In one case, pulmonary hypertension and ductal right to left shunt through ductus arteriosus and foramen ovale was objetivated by cardiac catheterization. Following intravenous prefusion of a pulmonary vasodilator (Tolazoline) patients showed a clinical amelioration and a definite increase in PaO2. Results and evolution with the use of this drug are commented.

Topics: Ductus Arteriosus, Patent; Female; Humans; Hyaline Membrane Disease; Hypertension, Pulmonary; Hypoxia; Infant, Newborn; Injections, Intravenous; Male; Meconium; Oxygen; Partial Pressure; Tolazoline

Thirty-nine critically ill infants with pulmonary disease received tolazoline because of severe hypoxemia refractory to administration of 100% O2 and mechanical ventilation. Twenty-seven (69%) of the infants responded with an increase in PaO2 greater than or equal to 20 torr in the first umbilical arterial gas after completion of the initial ten-minute infusion (1 to 2 mg/kg) of the drug. A response was not correlated with survival. The overall survival was 46%, essentially unchanged from our previous report (44%). Infants with hyaline membrane disease had the poorest survival rate (33%). Complications associated with the use of tolazoline occurred in 82% of the infants. A hypotensive reaction, defined as a 25% decrease in mean arterial pressure from the pre-tolazoline level, occurred in 67% of the infants, and more commonly in the infants with RDS (87%). In 11 infants who did not respond to the initial dose of tolazoline, the dose was increased up to 10 mg/kg/hour; only one infant responded, and eight (73%) had a hypotensive reaction.

Topics: Carbon Dioxide; Humans; Hyaline Membrane Disease; Hypoxia; Infant, Newborn; Infant, Newborn, Diseases; Inhalation; Lung Diseases; Meconium; Oxygen; Oxygen Inhalation Therapy; Respiration, Artificial; Respiratory Distress Syndrome, Newborn; Syndrome; Tolazoline; Umbilical Arteries

Hypoxia in newborn infants is becoming much easier to prevent, detect and treat. Nevertheless the successful management of potentially hypoxic fetuses and newborn infants remains the major challenge to all physicians concerned with perinatal care. What is at stake is not only that sick infants should survive, but equally or more importantly that the survivors should be normal children. Recent follow-up studies show that this aim can, with few exceptions, now be achieved (Stewart and Reynolds, 1974; Davies and Stewart, 1975; Durbin et al, 1976).

Topics: Apnea; Asphyxia Neonatorum; Blood Circulation; Humans; Hyaline Membrane Disease; Hypoxia; Infant, Newborn; Infant, Newborn, Diseases; Infant, Premature, Diseases; Lung Diseases; Meconium; Pneumothorax; Pulmonary Edema; Pulmonary Surfactants; Respiration; Vitamin K Deficiency Bleeding

The roentgenographic presentations of 11 newborn infants with hypoxemia secondary to pulmonary vasospasm and subsequent right-to-left shunting of blood through the foramen ovale and/or ductus arteriosus (persistent fetal circulation) are described (P. F. C. Syndrome). One infant had radiographically normal lungs, while ten had pulmonary parenchymal abnormalities including hyaline membrane disease [4], meconium aspiration syndrome [4], or an ill defined pattern of retained lung fluid [2]. The roentgenographic appearance of the lungs, however, was discordant with the severe hypoxemia observed in most. Heart size was variable but some degree of cardiomegaly was commonly present. Tolazoline, a potent vasodilator, was useful diagnostically and may have resulted in increased survival. An expanded clinical and roentgeonographic concept of the PFC syndrome is suggested.

Topics: Female; Humans; Hyaline Membrane Disease; Hypertension, Pulmonary; Hypoxia; Infant, Newborn; Male; Meconium; Pneumonia, Aspiration; Radiography; Syndrome; Truncus Arteriosus, Persistent

Meconium staining of the placenta and/or fetal body was present at birth in 10.3 per cent of 42,000 live-born infants, but present disproportionately in 18.1 per cent of 788 neonatal deaths. The neonatal mortality rate was 3.3 per cent in the stained group and 1.7 per cent in the nonstained group. Among infants who died, the incidence of erythroblastosis was quadrupled and that of cardiovascular malformation was doubled in the stained group. Meconium staining was associated with a decrease in the expected frequency of hyaline membranes and atelectasis even in premature infants; hypotheses for this phenomenon were presented. Meconium staining of the fetus or placenta requires several hours of exposure. As a hypothesis, the observed increase of deaths in stained neonates may be related to the stresses of cumulative or chronic hypoxia which may occur after the initial passage of meconium if delivery is prolonged.?23AUTHOR

Topics: Amniotic Fluid; Autopsy; Birth Weight; Congenital Abnormalities; Erythroblastosis, Fetal; Female; Fetal Diseases; Hemorrhage; Humans; Hyaline Membrane Disease; Hypoxia; Infant, Newborn; Infant, Newborn, Diseases; Meconium; Obstetric Labor Complications; Placenta; Pneumonia; Pregnancy; Pregnancy Complications; Pregnancy in Diabetics; Pulmonary Atelectasis; Time Factors

An infant is described who presented a complex cardiopulmonary problem which was evaluated with the help of new physiological techniques. the infant was born at term after an emergency Caesarian section for fetal distress and was found to have meconium aspiration. He remained persistently tachypnoeic and hypoxic despite high ambient oxygen. Chest radiography suggested cystic lesions at the lung bases, and lung function tests confirmed hyperinflation with delayed nitrogen washout. In addition the child had signs of Fallot's tetralogy, and this diagnosis was confirmed by cardiac catheterization. Because of persistent hypoxia and tachypnoea disproportionate to the cardiac condition, the possibility of localized lung disease was considered. Regional lung function tests were carried out in the neonatal period and again at six months of age useing radioisotopic 13N given by both inhalation and injection. These studies showed gross ventilation/perfusion imbalance in the lungs, particularly marked at the bases, but with enough generalized abnormality to preclude the possibility of surgical intervention. The principles of the measurement of lung mechanics in the newborn by whole-body plethysmography, nitrogen washout, and regional radioisotopic spirometry are outlined. The particular value of these techniques in the evaluation of complex disorders is discussed, especially where both cardiac and pulmonary abnormalities are present.

Topics: Airway Resistance; Cardiac Catheterization; Cesarean Section; Humans; Hypoxia; Infant, Newborn; Lung Compliance; Lung Diseases; Male; Meconium; Oxygen; Plethysmography, Whole Body; Radiography; Spirometry; Tetralogy of Fallot; Ventilation-Perfusion Ratio

Topics: Birth Weight; Blood; Diphosphoglyceric Acids; Erythrocytes; Female; Fetal Diseases; Gestational Age; Hematocrit; Humans; Hydrogen-Ion Concentration; Hypoxia; Infant, Newborn; Male; Meconium; Pregnancy; Umbilical Cord; Umbilical Veins

Topics: Adult; Amnion; Amniotic Fluid; Apgar Score; Female; Fetal Death; Fetal Diseases; Fetoscopy; Humans; Hypoxia; Infant Mortality; Infant, Newborn; Labor, Induced; Meconium; Pregnancy; Pregnancy, Prolonged

Topics: Abruptio Placentae; Amnion; Amniotic Fluid; Apgar Score; Endoscopy; Erythroblastosis, Fetal; Female; Fetal Death; Fetal Diseases; Fetoscopy; Humans; Hypoxia; Meconium; Placenta Previa; Pre-Eclampsia; Pregnancy; Pregnancy Complications; Pregnancy, Prolonged

Topics: Amniotic Fluid; Female; Fetal Diseases; Histocytochemistry; Humans; Hypoxia; Meconium; Pregnancy; Time Factors

Topics: Amniocentesis; Amniotic Fluid; Animals; Antigens; Antigens, Neoplasm; Female; Fetal Diseases; Goats; Humans; Hypoxia; Immune Sera; Meconium; Pregnancy; Radioimmunoassay

Topics: Acidosis; Apgar Score; Blood Specimen Collection; Bradycardia; Carbon Dioxide; Delivery, Obstetric; Female; Fetal Diseases; Gestational Age; Heart Rate; Humans; Hydrogen-Ion Concentration; Hypoxia; Infant, Newborn; Inhalation; Meconium; Methods; Monitoring, Physiologic; Oxygen; Pregnancy; Prognosis; Prospective Studies; Scalp; Tachycardia

Topics: Acceleration; Amniotic Fluid; Electrocardiography; Female; Fetal Heart; Heart Rate; Humans; Hypoxia; Labor, Obstetric; Meconium; Monitoring, Physiologic; Muscle Contraction; Oscillometry; Phonocardiography; Placenta Diseases; Pregnancy; Pregnancy Complications; Tachycardia; Umbilical Cord; Uterus

Topics: Adult; Amniotic Fluid; Female; Fetal Death; Fetal Diseases; Humans; Hypoxia; Jaundice; Meconium; Pregnancy; Pregnancy Complications

Topics: Amniotic Fluid; Electrocardiography; Endoscopy; Female; Fetal Diseases; Fetal Heart; Heart Rate; Humans; Hypoxia; Meconium; Pregnancy

Topics: Adolescent; Adult; Alkalosis; Amniotic Fluid; Blood Chemical Analysis; Female; Fetal Death; Fetal Diseases; Humans; Hydrogen-Ion Concentration; Hypoxia; Infant Mortality; Infant, Newborn; Meconium; Pre-Eclampsia; Pregnancy

Topics: Atropine; Bradycardia; Electrocardiography; Female; Fetal Diseases; Fetal Heart; Heart Auscultation; Heart Rate, Fetal; Humans; Hypoxia; Infant, Newborn; Maternal-Fetal Exchange; Meconium; Obstetric Labor Complications; Oxygen Inhalation Therapy; Pregnancy; Tachycardia

Topics: Amniotic Fluid; Asphyxia Neonatorum; Humans; Hypoxia; Infant, Newborn; Meconium; Physical Examination; Staining and Labeling