EFFECT OF CONTINUOUS POSITIVE AIRWAY PRESSURE BREATHING ON CARDIORESPIRATORY FUNCTION IN INFANTS WITH RESPIRATORY DISTRESS SYNDROME

Abstract A method of investigating the cardiorespiratory responses to continuous positive airway pressure (CPAP) in infants with respiratory distress syndrome is described. All measurements were made immediately before and within five minutes of application or any change in level of CPAP. Ventilation was derived from a pneumo-tachograph and dynamic compliance calculated. We have also measured arterial pH, oxygen and carbon dioxide tensions, arterial blood pressure and central venous pressure. Arterial oxygen tension increased in association with a decrease in the alveolar-arterial oxygen gradient. No consistent changes occurred in pH or carbon dioxide tension. Heart rate and mean arterial blood pressure remained the same but the arterial pulse pressure narrowed and the increase in central venous pressure averaged 17% of the applied airway pressure. There were less variations in both tidal volumes and instantaneous respiratory rates with CPAP compared with spontaneous breathing without CPAP. The respiratory rate decreased, but there were no consistent changes in tidal volume, resulting in a lesser reduction of minute ventilation. Dynamic compliance decreased on CPAP. With correct use of CPAP, and improvement in oxygenation generally occurs without obvious adverse cardiorespiratory effects. CPAP must nevertheless be used cautiously and in conjunction with close monitoring; because when the appropriate pressures are exceeded, it is possible that both circulatory and ventilatory function might be severely compromised.     

ALDOSTERONE AND SODIUM HOMEOSTASIS IN PRETERM INFANTS

Abstract A specific mass spectrometry method was used for tetrahydroaldosterone determination in urine of preterm infants (26–34 weeks gestational age) up to 9 weeks of age. Hyponatremia during the first 2 weeks of life was associated with an excretion of tetrahydroaldosterone (5–50 μg/24 h) comparable with full-term infants. Excretion of tetrahydroaldosterone was significantly elevated in all infants studied during the third week of life (80–350 μg/24 h) and this was associated with establishment of positive sodium balance. The excretion of tetrahydroaldosterone remained high for 2 or 3 weeks. The results are discussed in relation to the development of renal tubules and control mechanisms for sodium homeostasis.     

肺表面活性物质预防早产儿RDS的临床观察

目的 探讨肺表面活性物质(PS)预防用药对预防早产儿呼吸窘迫综合征(RDS)及改善早产儿预后的可行性。方法 我院胎龄≤32W的早产儿12例,于生后预防应用PS(预防组);同期确诊为RDS 17例应用呼吸机和PS(治疗组),比例两RDS发生率、呼吸机参数、并发症及预后。结果 预防组RDS发生3例,发生率为25％,低于我院同期收治的≤32W早产儿RDS发生率(43％);预防组RDS 3例均为Ⅱ期,治疗组Ⅲ期、Ⅳ为52.9％(9/17)。预防组上呼吸机所需压力明显低于治疗组,(P<0.05);肺炎、感染、颅内出血等合并症有下降趋势;未有气漏及BPD的发生。结论 PS预防用药可降低早产儿RDS发生率及减轻发病程度,减少呼吸机的应用,减少并发症,改善早产儿预后。     

UMBILICAL CORD CORTISOL AND PROLACTIN LEVELS IN PRETERM INFANTS

ABSTRACT. The influence of labor and route of delivery upon the umbilical cord serum levels of cortisol and prolactin in ninety-nine preterm infants not exposed prenatally to corticosteroids was studied. Vaginally born infants (group A) presented a higher mean cord cortisol concentration than those delivered by cesarean section (group B); mean prolactin values, however, were not different between both groups. Although there was no difference in cortisol and prolactin levels between infants delivered by cesarean section after spontaneous onset of labor (group B-I) and those without labor (group B-II), the mean cortisol concentration was significantly higher in group A than in group B-I. The mean prolactin levels did not differ among all the studied groups. It is concluded that there is no association between presence of labor or route of delivery and cord seum levels of prolactin, there is no association between spontaneous preterm labor and cord cortisol values and there is an association between vaginal delivery and high cord cortisol levels in preterm infants. It is suggested that the increase in serum cortisol levels does not precede the initiation of preterm parturition but it is secondary to the stress caused by vaginal delivery.     

EARLY CLOSURE OF PATENT DUCTUS ARTERIOSUS WITH INDOMETHACIN IN PRETERM INFANTS WITH IDIOPATHIC RESPIRATORY DISTRESS SYNDROME

ABSTRACT. Thirty-seven preterm infants with idiopathic respiratory distress syndrome were prospectively studied for the effect of the early closure of patent ductus arteriosus with indomethacin on the course of idiopathic respiratory distress syndrome. Serial retrograde aortograms were performed in all infants in order to visualize the ductus arteriosus, apart from three patients, who died early and were evaluated aortographically only once. The ductus was initially open in 27 infants and closed in 10 infants. The infants with open ductus arteriosus were randomly divided into two groups. The first group consisted of 13 infants, in whom the ductus was closed with indomethacin at a median age of 18 hours. The other 14 infants served as controls. Total time on assisted ventilation and duration of exposure to additional oxygen were significantly shorter in medicated infants than in controls. Oxygenation of infants with an initially closed ductus was better from birth and duration of their ventilatory assistance and oxygen exposure were shorter than in infants with initial ductal shunting. The data suggest that the early closure of the patent ductus arteriosus with indomethacin in distressed preterm infants has a favourable effect on the course of idiopathic respiratory distress syndrome.     

STUDY OF HEART RATE VARIABILITY IN SICK NEWBORN INFANTS

Abstract. Jenkins, J. G., Reid, M. McC. and McClure, B. G. (Special Care Baby Unit, Royal Maternity Hospital, and Department of Child Health, Queen's University, Belfast, N. Ireland). Study of heart rate variability in sick newborn infants. Acta Paediatr Scand, 69: 393, 1980.—Heart rate variability has been studied in a group of 66 newborn infants for periods of up to 72 hours from birth. Long term variability was reduced in infants suffering from the idiopathic respiratory distress syndrome and this was more marked with severe respiratory distress requiring mechanical ventilation. Persistent reduction in long term variability was associated with increased mortality. Reduction in heart rate variability may be due to high levels of sympathetic activity.     

PERITONEAL DIALYSIS IN THE TREATMENT OF HYALINE MEMBRANE DISEASE OF NEWBORN PREMATURE INFANTS

Intermittent or continuous PD has been employed in the treatment of 50 selected cases of HMD of premature infants. Twenty-one infants treated by this method recovered, whereas only 7 of 42 survived in a comparable control group, treated with alkali and glucose.     

EFFECTIVE PULMONARY CAPILLARY BLOOD FLOW IN INFANTS WITH BIRTH ASPHYXIA

ABSTRACT. Effective pulmonary capillary blood flow was measured on the first day of life in twenty term infants with birth asphyxia and twenty-five normal term infants. The infants studied showed no clinical or laboratory evidence of respiratory distress. The mean effective pulmonary capillary blood flow of 121 ml/kg/min in the birth asphyxia group was significantly lower than the mean of 162 ml/kg/min in the normal group. The possible relationship of birth asphyxia and pulmonary hypoperfusion in the aetiology of the idiopathic respiratory distress syndrome is discussed.     

EFFECTIVE PULMONARY CAPILLARY BLOOD FLOW IN INFANTS WITH BIRTH ASPHYXIA

Abstract. Effective pulmonary capillary blood flow was measured on the first day of life in twenty term infants with birth asphyxia and twenty-five normal term infants. The infants studied showed no clinical or laboratory evidence of respiratory distress. The mean effective pulmonary capillary blood flow of 121 ml/kg/min in the birth asphyxia group was significantly lower than the mean of 162 ml/kg/min in the normal group. The possible relationship of birth asphyxia and pulmonary hypoperfusion in the aetiology of the idiopathic respiratory distress syndrome is discussed.     

COMPARISONS BETWEEN SERUM CONCENTRATIONS OF THYROXINE AND THYROXINE-BINDING PROTEINS IN SAMPLES SIMULTANEOUSLY OBTAINED FROM CAPILLARY, PERIPHERAL VEIN, CENTRAL VEIN AND AORTA IN NEWBORN INFANTS

Abstract. Jacobsen, B. B. and Peitersen, B. (University Clinic of Paediatrics, Children's Hospital, Fuglebakken, Copenhagen, Denmark). Comparisons between serum concentrations of thyroxine and thyroxine-binding proteins in samples simultaneously obtained from capillary, peripheral vein, central vein and aorta in newborn infants. Acta Paediatr Scand, 68: 43, 1979.—A total number of 40 newborn infants with various maturity were studied: 13 babies without perinatal events, 19 infants recovered from transient diseases, 6 infants with idiopathic respiratory distress syndrome and 2 infants with asphyxia indicating artificial ventilation. Comparisons were performed between serum concentrations of thyroxine (T₄), thyroxine-binding globulin (TBG), prealbumin (TBPA) and albumin (Alb) in capillary versus peripheral vein, aorta versus central vein and, finally, in peripheral versus central veins. In healthy infants serum T₄ concentrations in capillary blood and peripheral vein did not differ significantly. Although serum concentrations of thyroid hormone-binding proteins tended to be increased in aortic compared to central venous specimens no statistically significant differences appeared. In infants in good clinical conditions serum T₄, TBG, TBPA, and Alb levels were 6–8% higher in peripheral than in central veins, possibly primarily due to a hemo-concentrating effect of venous stasis. Therefore, in evaluation of the thyroid variables in newborn infants the technique of blood sampling must be considered. In most infants with idiopathic respiratory distress syndrome and in one asphyxiated baby a remarkable tendency to a low serum TBG and T₄ concentration in peripheral compared to central vein samples, were observed.     

ERYTHROPOIETIN LEVELS IN CORD BLOOD OF CONTROL INFANTS AND INFANTS WITH RESPIRATORY DISTRESS SYNDROME

Erythropoietin levels (ESF) were measured in premature infants with and without the respiratory distress syndrome in an effort to define the role of intrauterine hypoxia in the genesis of the disease. No difference in levels could be detected between infants with and without the: respiratory distress syndrome. This suggests that either intrauterine hypoxia plays no role in the genesis of the respiratory distress syndrome or that the hypoxia is (1) of short duration, (2) of relatively long duration, or (3) remote with respect to the time of birth. The higher levels found in full-term infants suggested that hypoxia before birth is a more common feature of the term delivery than the premature delivery.     

RESPIRATORY INSUFFICIENCY SYNDROME (RIS) IN PRETERM INFANTS WITH GESTATIONAL AGE OF 32 WEEKS AND LESS

ABSTRACT: Carlsson, J. and Svenningsen, N. W. (Department of Paediatrics, University Hospital, Lund, Sweden). Respiratory insufficiency syndrome (RIS) in preterm infants with gestational age of 32 weeks and less. Neonatal management and follow-up study. Acta Paediatr Scand, 64: 813, 1975.–The clinical entity of respiratory insufficiency syndrome (RIS), i.e. irregular breathing leading to recurrent apnea and bradycardia in an otherwise healthy preterm infant, has been studied in respect of symptomathology and management with intensive case including ventilatory support. During a 4-year period 26 of 103 infants with gestational age 32 weeks and mean birth weight 1304 g (range 710 to 1830 g) developed RIS. In most infants the initial apnea occurred after 2 and before 72 hours post delivery but in some infants later. Because of progressive hypoxemia and acidosis IS of the 26 RIS infants required IPPV treatment. The 76 % survival rate of RIS infants seems to justify intensive care with ventilatory support even in the smallest preterm infants with RIS, especially as the follow-up study performed at 15 months to 3 ½ years of age showed neurological sequelae in only 3 of 20 surviving babies, i.e. 15 % sequelae rate.     

RENAL FUNCTION IN IDIOPATHIC RESPIRATORY DISTRESS SYNDROME

ABSTRACT. Renal function was studied in 11 pre-term infants with idiopathic respiratory distress syndrome (IRDS) grade 1 according to Prod'hom's criteria. As a reference 16 healthy pre-term infants were studied. The groups did not differ with regard to mean gestational age (GA) and mean postnatal age (PNA). The studies were preformed twice, first at a PNA of 33–37 hours and then at 132–148 hours. GFR and C_PAH were determined with the single injection technique and the ability to excrete Na was determined following an oral Na⁺ load. GFR was higher in IRDS infants at the first investigation and slightly lower in IRDS infants at the second investigation. The GFR correlated to the lowest recorded P_ao2 r=0.45) in IRDS infants. C_PAH was similar in IRDS and controls at the first, and lower in IRDS infants at the second investigation. The urinary Na⁺ excretion was significantly higher in IRDS infants. Treatment with digitalis was in part responsible for the high urinary Na⁺ excretion. The IRDS infants had a higher Na⁺ and glucose intake than the control infants. It is suggested that this higher intake is in part responsible for the relatively high GFR and urinary Na⁺ excretion in the IRDS infants.     

RENAL FUNCTION IN NEWBORN INFANTS WITH HIGH HEMATOCRIT VALUES BEFORE AND AFTER ISOVOLEMIC HAEMODILUTION

ABSTRACT. Aperia, A., Bergqvist, G., Broberger, O., Thodenius, K. and Zetterström, R. (Department of Paediatrics, St Göran's Children's Hospital, Kardinska Institutet, Stockholm, Sweden). Renal function in newborn infants with high hematocrit values, before and after isovolemic hernodilution. Acta Paediatr Scand 63: 878, 1974.—To evaluate the effect of high hematocrit (secondary polycythemia) on renal function in newborn babies, 10 infants with values above 70% have been studied before and after an isovolemic hemodilution. By replacing blood with a solution containing albumin, glucose and sodium chloride the hematocrit was reduced to about 60%. Hematocrit, blood viscosity, glomerular filtration rate (single injection technique), and the renal response to an oral sodium and fluid load were determined before and after hemodilution. The fall in hematocrit was accompanied by a concomitant fall in blood viscosity. All parameters of renal function which were studied were low before hemodilution but improved after this procedure. Water excretion increased out of proportion to glomerular filtration rate. It is suggested that the reduction in renal function as seen in newborn infants with high hematocrit are secondary to an impairment of glomerular plasma flow which in turn is the consequence of high viscosity. The depression of renal function as seen in polycythemic newborn infants may cause marked changes in the handling of certain drugs.     

允许性高碳酸血症通气法治疗新生儿呼吸窘迫综合征

目的 探讨允许性高碳酸血症通气法(PHV)在治疗新生儿呼吸窘迫综合征(NRDS)中的价值。方法 随机选择两组需机械通气治疗的NRDS病人,对照组(n=25)以传统通气方式治疗,PHV组(n=31)降低PIP、PEEP、MAP等通气条件,允许血气中PaCO_2超过正常值,在45～55mmHg之间,比较两组通气条件、通气过程中血气值及并发症、病死率。结果 两组在通气过程中,PaCO_2/FiO_2及PaCO_2无显著性差异(P均>0.05),而pH值、PaCO_2有显著性差异(P<0.05和P<0.01),同时PHV组上机时间显著减少(P<0.05),气漏发生率和病人死亡率均降低(0/12％和12.9％/24％)。结论 PHV法在治疗NRDS中较传统通气方式能降低并发症的发生率及病死率,具有推广价值。     

TOLAZOLINE AND DOPAMINE THERAPY IN NEONATAL HYPOXIA AND PULMONARY VASOSPASM

Abstract. Hegyi, T. and Hiatt, I. M. (Division of Perinatology, Monmouth Medical Center and Department of Pediatrics, the Hahnemann Medical College, Philadelphia, USA). Tolazoline and dopamine therapy in neonatal hypoxia and pulmonary vasospasm. Acta Paediatr Scand, 69: 101, 1980.—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 3300 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 P_aO2 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     

肺表面活性物质早期给药对新生儿呼吸窘迫综合征的影响

目的 探讨肺表面活性物质(Curosurf)早期给药对极低出生体重儿呼吸窘迫综合征(MRDS)近期预后的影响。方法 对26例患NRDS的极低出生体重儿给予Curosurf治疗并进行临床对照实验。结果 NRDS患儿给药后12小时Po2/FiO2显著上升,分别为(252.53±49.45)和(184.47±35.04),与给药前比较均P<0.01;比较早期给药组(生后2 h内)和普通治疗组,有创机械通气时间分别为(54.55±11.21)h和(112.00±84.93)h,t=2.217,P<0.05,差异有显著性。患儿体重恢复至出生时水平分别为(11.55±3.70)d和(15.27±4.71)d,t=2.171,P<0.05;贫血出现的时间分别为(21.64±4.48)d和(12.60±4.91)d,t=4.807,P<0.01,差异有显著性;结论 对于极低出生体重儿NRDS,早期给予Curosurf可明显改善近期预后,提高存活率。     

THE TRANSCAPILLARY ESCAPE RATE OF T-1824 IN NEWBORN INFANTS OF DIABETIC MOTHERS AND NEWBORN INFANTS WITH RESPIRATORY DISTRESS OR BIRTH ASPHYXIA

ABSTRACT. Ingomar, C. Joh. and Klebe, J. G. (Diabetes Center of the Royal Maternity Hospital and the University Department for Newborn Infants, Rigshospitalet, Copenhagen, Denmark). The transcapillary escape rate of T-1824 in newborn infants of diabetic mothers and newborn infants with respiratory distress or birth asphyxia. Acta Paediatr Scand, 63: 565, 1974.—The influence of certain clinical conditions (idiopathic respiratory distress, birth asphyxia and diabetic embryopathy) on the transcapillary escape rate of human albumin, was investigated in 52 newborn infants. The dyestuff T-1824 (Evan's blue) was used for the labelling of plasma albumin in vivo, and its plasma concentration was determined spectrophotometrically using a micro-method. From serial measurements carried out during the first hour following the injection of T-1824, the escape rate (%/hour) was calculated. Among healthy newborn infants the escape rate was found to increase proportional to the magnitude of the placental transfusion. The same applied to infants with respiratory distress and infants of diabetic mothers, the escape rate of whom did not differ from that of healthy infants. By contrast, the escape rate of albumin was, among some cases of birth asphyxia, found to be increased out of proportion to the placental transfusion, which the infants had received. It is discussed whether the increased escape rate found in these cases is caused by an increased capillary permeability or an increased capillary surface area.     

VARIATIONS OF PROTEASE INHIBITORS IN FOETUSES, NEWBORN INFANTS and IN SOME NEONATAL DISORDERS

ABSTRACT: Sveger, T. and Ekelund, H. (Departments of Clinical Chemistry and of Paediatrics, Malmö General Hospital, Malmö, Sweden). Variations of protease inhibitors in foetuses, newborn infants and in some neonatal disorders. Acta Paediatr Scand, 64:763, 1975.–Low levels of protease inhibitors have been found on the 1st day of life in IRDS infants. 19 IRDS infants were studied together with foetuses and control term and preterm infants. α₁-antitrypsin, antichymotrypsin and α₂-macroglobulin were measured with the electroim-muno assay. IRDS infants had significantly reduced concentration of α₁-antitrypsin and antichymotrypsin on the 1st day, the level increasing to normal on the 2nd day. In foetuses α₁-antitrypsin was normal, antichymotrypsin 2% and α₂-macroglobulin 1/3 of the normal adult level. The protease inhibitors are increased in infants born after premature rupture of foetal membranes. The part, if any, played by protease inhibitors is not entirely understood. The inhibitors may, theoretically, be of some importance in the dissolution of the hyaline membranes, protect against pulmonary vasoconstriction, protect pulmonary tissue against leucocyte and macrophage proteolytic enzymes and inhibit the release of or counteract vasoactive substances that might take part in the development of shock in IRDS babies.