Cause Of Neonatal Respiratory Distress Research Articles

Developmental and genetic aspects of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a frequent occurring cause of neonatal respiratory distress and occurs 1 in every 3,000 liveborns. Ventilatory support and pharmaceutical treatment of the co-occurring lung hypoplasia and pulmonary hypertension are insufficient in, respectively, 20% of isolated cases and 60% of complex ones leading to early perinatal death. The exact cause of CDH remains to be identified in the majority of human CDH patients and prognostic factors predicting treatment refraction are largely unknown. Their identification is hampered by the multifactorial and heterogenic nature of this congenital anomaly. However, application of high-resolution molecular cytogenetic techniques to patients' DNA now enables detection of chromosomal aberrations in 30% of the patients. Furthermore, recent insights in rodent embryogenesis pointed to a specific disruption of the early mesenchymal structures in the primordial diaphragm of CDH-induced offspring. Together, these data allowed for the introduction of new hypotheses on CDH pathogenesis, although many issues remain to be resolved. In this review, we have combined these new insights and remaining questions on diaphragm pathogenesis with a concise overview of the clinical, embryological, and genetic data available.

Bronchogenic cyst, an unusual cause of respiratory distress in a neonate

Objective : To present an unusual cause of neonatal respiratory distress. Materials and methods : Case report and review of the literature. Results : A premature neonate was born with biphasic stridor requiring intubation soon after birth. Endoscopic evaluation of the airway after two failed extubations revealed extrinsic compression of the intrathoracic trachea at the level of the carina and right mainstem bronchus. An MRI revealed a cyst in close relationship with the carina with splaying of the mainstem bronchi. The cyst was excised through a thoracotomy and pathology confirmed the diagnosis of a bronchogenic cyst. The patient was successfully extubated after the procedure. Conclusion : Bronchogenic cysts are rare and can cause severe lower airway obstruction in the newborn. Surgical excision is recommended in all symptomatic patients to provide definitive histologic diagnosis, alleviate symptoms, and prevent the development of associated complications.

Newborn Respiratory Disorders

Newborn Respiratory Disorders

Impact of Labor on Outcomes in Transient Tachypnea of the Newborn: Population-Based Study

Transient tachypnea of the newborn (TTN) is the most common cause of neonatal respiratory distress; its estimated incidence is 1 % to 2%. Although a number of risk factors for TTN have been identified, the main risk factors include elective cesarean section (ECS), lower gestational age, male gender, and low birth weight. Previous studies have shown a positive impact of labor on respiratory outcomes among infants with TTN, but the impact of labor on the severity of TTN has not been investigated. This population-based cohort study investigated the effect of labor on the risk and course of TTN in a large, representative sample of term singleton neonates in Germany. Between 2001 and 2005, perinatal databases in the federal states of Hesse and Saarland were used to identify cases of TTN among singletons born at a gestational age ≥37 weeks, and to examine neonatal outcomes in all infants admitted to a neonatal center. Data for the TTN group was compared with national perinatal data for term singletons (control group) born during the study period. The International Classification of Diseases, 10th Revision was used to diagnosis TTN. Of the 239,971 term births included in the final analysis, 13,346 (5.6%) were transferred to a neonatal ward and 1423 (0.59%) cases of TTN were diagnosed. This represented an overall TTN incidence of 5.9 cases per 1000 singleton live births. Risk factors for TTN included ECS, low gestational age, male gender, and low birth weight. There was a significant association between the absence of labor before birth and longer duration of oxygen supplementation (P < 0.02), and an increased risk of TTN and severity of TTN at term. Prolonged labor reduced the need for oxygen supplementation and conversely, a decrease in labor duration increased the need (P < 0.028). These findings show that ECS and the absence of labor at term are strong risk factors for the development of TTN. Absence of labor or reduced labor duration is associated with increased severity of TTN and the need for oxygen supplementation.

Primäre Ziliendyskinesie als Ursache neonataler Atemnot

Primary ciliary dyskinesia (PCD) is a hereditary disorder of structure and function of the cilia of respiratory epithelium of the upper and lower airways. Prevalence is estimated with 1:15 000 to 1:30 000 births. We present a newborn infant with respiratory distress caused by PCD. On the first day of life, the male newborn developed dyspnoe and cyanosis, so that CPAP and short term ventilation was necessary. Varying atelectasis impressed on the chest radiographs and the diagnosis of PCD was made by nasal brush biopsies. Causative is a lack of the inner dynein arms of the cilia. The clinical features of newborns with the diagnoses of PCD are listed and compared with the own case. PCD is a rare cause of neonatal respiratory distress and should be considered in term infants with unknown and prolonged course even if Situs inversus is lacking.

Early development of the primordial mammalian diaphragm and cellular mechanisms of nitrofen‐induced congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a frequently occurring cause of neonatal respiratory distress and is associated with high mortality and long-term morbidity. Evidence from animal models suggests that CDH has its origins in the malformation of the pleuroperitoneal fold (PPF), a key structure in embryonic diaphragm formation. The aims of this study were to characterize the embryogenesis of the PPF in rats and humans, and to determine the potential mechanism that leads to abnormal PPF development in the nitrofen model of CDH. Analysis of rat embryos, and archived human embryo sections, allowed the timeframe of PPF formation to be determined for both species, thus delineating a critical period of diaphragm development in relation to CDH. Experiments on nitrofen-exposed NIH 3T3 cells in vitro led us to hypothesize that nitrofen might cause diaphragmatic hernia in vivo by two possible mechanisms: through decreased cell proliferation or by inducing apoptosis. Data from nitrofen-exposed rat embryos indicates that the primary mechanism of nitrofen teratogenesis in the PPF is through decreased cell proliferation. This study provides novel insight into the embryogenesis of the PPF in rats and humans, and it indicates that impaired cell proliferation might contribute to abnormal diaphragm development in the nitrofen model of CDH.

Hyperparathyroidism secondary to maternal hypoparathyroidism and vitamin D deficiency: an uncommon cause of neonatal respiratory distress

A 4-day-old neonate presented with respiratory distress owing to chest wall deformity associated with metabolic bone disease. He was found to have congenital hyperparathyroidism and his mother was suffering from post-surgical hypoparathyroidism and vitamin D deficiency. The patient was given calcium lactate and maintenance doses of vitamin D. The respiratory distress subsided, the parathyroid hormone level returned to normal and by 4 weeks of age bone mineral content had improved. Congenital hyperparathyroidism should be considered in neonates presenting with respiratory distress and chest deformity.

Ultrastructural changes in the lungs of neonatal rats intratracheally inoculated with meconium.

Meconium aspiration syndrome has been for many years an important cause of neonatal respiratory distress in newborn babies and sporadically reported in animals. This investigation was designed to study the ultrastructural and morphometric changes in the lungs of neonatal rats following the intratracheal inoculation of meconium. Seven-day-old Fischer-344 rats (n = 24) were randomly allocated in two groups. One group was intratracheally inoculated with saline solution and the second group received homologous meconium. Neonates were euthanatized at 1, 3 and 7 postinoculation days (PID) and lungs were examined by light and electron microscopy. Saline solution did not induce any ultrastructural changes in the lung. In contrast, meconium induced deciliation, recruitment of neutrophils and pulmonary alveolar macrophages to the bronchoalveolar space, intravascular sequestration of neutrophils and aggregation of platelets at PID 1 and 3. Other ultrastructural changes at PID 1 and 3 included interstitial edema and escape of red cells and fibrin into the alveolar space and interstitium. Interstitial edema and sequestration of neutrophils were responsible for the significant increase in thickness of alveolar septa. At PID 7 there was hyperplasia and enlargement of type II pneumocytes as well as interstitial proliferation of mesenchymal cells with intra-alveolar fibrosis. It was concluded that intratracheal inoculation of meconium in neonatal rats induces acute ultrastructural changes followed by a reparative response.

The neonatal chest X-ray

The chest X-ray is the most valuable imaging modality in the assessment of the neonate with respiratory distress. Whilst many of the radiological appearances are relatively non-specific, integration of the clinical features with the X-ray appearances will help the clinician arrive at the correct diagnosis in most cases. In a minority of infants, particularly those with a congenital malformation of the chest or airways other imaging modalities may be required. This paper will describe the radiological appearances of the most important causes of neonatal respiratory distress and highlight those situations where more complex investigations are necessary.

Warren Zapol: true-life adventures in science, medicine, and innovation: recipient of the 1999 Excellence in Research Award.

Warren Zapol: true-life adventures in science, medicine, and innovation: recipient of the 1999 Excellence in Research Award.

The surface and transport properties of meconium and reconstituted meconium solutions.

Passage of meconium in utero and subsequent pulmonary aspiration of meconium admixed with amniotic fluid is a major cause of neonatal respiratory distress. Airway clearance is the first defense of the lung, and clearance is dependent on the bulk physical (rheologic) as well as the surface properties of airway material. We therefore evaluated the surface adhesive properties and the transport properties of freshly passed meconium and of two dilutions of reconstituted, blended, meconium as used to mimic the effect of meconium passage into the amniotic fluid in animal models of meconium aspiration syndrome. Reconstituted and fresh meconium had similar physical and transport properties, including an extremely high interfacial (adhesion) tension and very poor transportability by either airflow or cilia. The similarities between the freshly passed and reconstituted meconium suggest that the latter is an adequate substitute for use in animal models of meconium aspiration syndrome. The high adhesiveness of meconium suggests a potential role for surfactant administration as an adhesive to improve airway clearance after meconium aspiration.

Kartagener syndrome: an uncommon cause of neonatal respiratory distress?

Kartagener syndrome: an uncommon cause of neonatal respiratory distress?

A common presentation of an uncommon cause of neonatal respiratory distress: Pneumonia alba

While lung involvement is an uncommon presentation of congenital syphilis, respiratory distress is a common leading symptom in sick newborns. We describe an infant who presented with respiratory distress thought to be secondary to congenital syphilis and discuss the findings suggestive of an etiology other than respiratory distress syndrome (RDS).

Nasal obstruction in the neonate secondary to nasolacrimal duct cysts

The neonate is an obligate nasal breather and any form of nasal obstruction causes respiratory distress during feeding and sleeping. We report two patients with unusual causes of respiratory distress secondary to nasolacrimal duct cysts. The failure of the lacrimal duct to perforate at the distal end results in dacryocystitis and cyst formation. Removal of the nasal wall of the cyst resolves the obstruction and the dacryocystitis. The nasolacrimal duct cyst is an unusual, but readily treated, cause of neonatal respiratory distress.

Pitfalls to Laser Correction of Choanal Atresia

Many methods have been used over the years to correct choanal atresia, a cause of neonatal respiratory distress. The precise, relatively bloodless incisions of the carbon dioxide laser have made it an effective tool for laser surgery using a transnasal approach. In spite of its utility, certain conditions impede laser surgery. These conditions include septal deviation, enlarged inferior turbinates, high arched hard palate, and other craniofacial disorders. Prolonged duration of stenting appears to reduce the success rate.

Total lung lavage for pulmonary alveolar proteinosis in an infant without the use of cardiopulmonary bypass

Pulmonary alveolar proteinosis is a rare disease that usually affects the adult patient, but is now being recognized as a possible cause of neonatal respiratory distress. In the adult patient, whole lung lavage, as described by Ramirez-R in 1965, is considered the most effective therapy for management of this condition. The lavage can be accomplished safely and with relative ease by using a Carlens or Robertshaw tube to isolate and lavage one lung while ventilating the other. The unavailability of a small double-lumen tube makes this procedure impossible in the pediatric age group. Therefore, whole lung lavage has been possible in only a few children in the past with the help of cardiopulmonary bypass to allow simultaneous oxygenation during the pulmonary lavage. Due to the hazards and technical difficulties of cardiopulmonary bypass, total pulmonary lavage can not be considered a practical option in the very small infant. A 15-week-old infant is reported, weighing 2 kg with a diagnosis of pulmonary alveolar proteinosis, who underwent total pulmonary lavage safely on three different occasions without employing cardiopulmonary bypass. A double-lumen Swan-Ganz catheter, introduced transbronchoscopically through the side-arm of a rigid, 3.5-mm Storz bronchoscope was used to isolate and lavage one lung while ventilation to the other lung was maintained through the bronchoscope. A Nellcor oximeter, utilized for transcutaneous monitoring, revealed satisfactory oxygen saturation during the entire pulmonary lavage. The transbronchoscopic lavage was monitored under direct vision with a video monitor, ensuring correct position of the bronchoscope and the catheter at all times.(ABSTRACT TRUNCATED AT 250 WORDS)

Immotile cilia syndrome: a new cause of neonatal respiratory distress.

Kartagener's syndrome is a condition that consists of situs inversus, bronchiectasis, and sinusitis. Some patients have respiratory symptoms that date from early infancy, and electron microscopical examination has shown that adults with this condition lack dynein arms in ciliary microtubules. It has been suggested that an inherited defect in ciliary ultrastructure, the immotile cilia, is the basis for the syndrome. We report 6 patients who presented within the first 24 hours of life with tachypnoea, retraction, rales, and dextrocardia. Five of them had situs inversus. They all responded to physiotherapy after antibiotics had failed to improve their condition. Electron microscopical examination of the cilia in 2 of the infants confirmed deficiency of dynein arms. All 6 infants had recurrent respiratory infections. Four went on to develop recurrent otitis media, 2 had sinusitis, and 1 now has bronchiectasis. The immotile cilia syndrome should be added to the list of causes of respiratory distress in newborn infants. The condition is worth diagnosing because of the good response to physiotherapy, and because of the likelihood of recurrent respiratory problems.

1672 NON-ASSOCIATION OF CELL CONTENT WITH RESPIRATORY DISTRESS IN ADULT RABBITS ASPIRATING HUMAN AMNIOTIC FLUID (AF)

Aspiration of uncontaminated AF is considered by some to be one cause of neonatal respiratory distress due to alveolar plugging by its cellular content. We examined the degree of respiratory compromise that occurred in adult rabbits after being administered human AF of varying cell counts. Experimental groups received either 4 or 6 cc/kg of human AF (n=15), saline (n=9), a 10% meconium solution (n=10), or nothing (n=6). Saline was used to provide a control fluid without solid elements while meconium was included to ensure that the experimental model could produce a well-characterized aspiration syndrome. There was one death in the AF group, O in the saline group and 5/10 meconium animals died. The epithelial cell count of the AF samples (n=15, mean= 717 cells/ml3, range=15-2370) was slightly higher than previously reported values (Ob Gyn 49:280). There was no correlatio between the cell count of the AF aspirated and the PO2 at 10, 30, 60 and 90 min and 2, 6 and 24 hrs, nor with lung weight or residual volume. Pressure-volume curves of AF animals were nearly identical with those of controls. Histological finding were similar in the AF and control groups with regard to leukocytes, alveolar macrophages and atelectasis. These findings indicate no correlation between AF cell count and the degree of respiratory compromise and lung pathology in adult rabbits.

The differential leukocyte count in the assessment and outcome of early-onset neonatal group B streptococcal disease

The usefulness of the differential white blood cell count in distinguishing early-onset group B streptococcal disease from other causes of neonatal respiratory distress was studied in 45 infants with culture-proved infection. The initial diagnosis was hyaline membrane disease in 19 infants, wet lung syndrome 13, and other causes of respiratory distress in 13. Thirty-nine (87%) had abnormal absolute neutrophil counts, 25 with neutropenia and 14 with neutrophilia. The absolute immature neutrophil count was elevated in 19 infants (42%). Forty-one infants (91%) had an abnormal immature neutrophil to total neutrophil ratio. All infected infants were identified when both the absolute total neutrophil count and ratio were used. The differential white cell count appears to be a useful tool for screening infants presenting with respiratory distress in the first 48 hours of life and for separating early-onset group B streptococcal disease from other causes of neonatal respiratory distress.

Transient tachypnea of newborn. Possible delayed resorption of fluid at birth.

DESPITE recent attempts to distinguish the multiple causes of neonatal respiratory distress, there remains a group of infants in whom none of the previously described disorders can be shown to exist. Over the past three years we have encountered eight infants who have much in common and who, therefore, probably constitute a previously undescribed syndrome. All but one have been full-term infants in whom respiratory distress, characterized chiefly by tachypnea, has occurred at or near the time of birth and persisted for several days with subsequent complete clearing. Their clinical course and the radiographic findings help to distinguish them from other infants with pneumonia, aspiration, heart failure, and congenital malformations. Description of Patients In none of the cases was there evidence of maternal infection or hemorrhage. One of the mothers had toxemia of pregnancy; another, excessive weight gain. Only one of the eight infants was delivered by cesarean section. There