History Of Respiratory Distress Syndrome Research Articles

BRONCHOPULMONARY DYSPLASIA: TREATMENT AND PREVENTION

Since 1967, when it was first defined and described the nature and definition of bronchopulmonary dysplasia (BPD) has evolved. Based on clinical and radiographic evidence of pulmonary disease in moderately to late premature infants with a history of respiratory distress syndrome, BPD was familiarly defined as a chronic form of lung disease in neonates treated with oxygen and positive pressure ventilation for a primary lung disorder, the nature of BPD has evolved into a “new” form of BPD typically seen in neonates surviving at the threshold of viability and characterized primarily by arrest of alveolar and vascular development. Infants develop BPD in about 1.5% of all newborn births. The incidence of BPD appears to be growing in conjunction with the increased survival of very-low-birth-weight infants who are treated for and recover from respiratory distress syndrome (RDS). This review has been an up-date of literature data, including animal studies, human pilot studies, randomized controlled trials (RCTs), meta-analyses and systematic reviews published on the PubMed data base.

Pleuropulmonary Blastoma (PPB) in an infant: Is the timing of an elective resection of neonatal lung lesions challenged?

Abstract Congenital Pulmonary Airway Malformations (CPAMs) are abnormalities of lung parenchyma that are often diagnosed upon prenatal imaging as opposed to postnatal symptoms. With a clinical presentation identical to CPAMs, Pleuropulmonary Blastoma (PPB) is a rare pulmonary neoplasm of highly malignant potential. We present a rare case of a female infant with a vague medical history of respiratory distress syndrome (RDS) at birth, presenting with a tension pneumothorax at three months of age, thought initially to be secondary to CPAM, but found to be PPB upon surgical resection and histological analysis. PPB is a rare pulmonary neoplasm of childhood that originates from the primitive interstitium of the lung, resulting in lesions that can be highly malignant. It is classified as type I (cystic), type II (cystic/solid) or type III (solid), with a progression of disease and worsening prognosis from type I to type III. Due to the cystic nature of CPAM and PPB it is difficult to differentiate on imaging alone; diagnosis must be made based on histological analysis. The highly malignant nature and potential for morbidity and mortality of PPB should make clinicians consider early resection of cystic lung lesions preferentially on an elective basis.

Respiratory Distress Syndrome at Birth Is a Risk Factor for Hospitalization for Lower Respiratory Tract Infections in Infancy

Respiratory distress syndrome (RDS) and hospitalization for lower respiratory tract infection (LRTI; specifically, respiratory syncytial virus) are important causes of morbidity in infancy. Whether RDS at birth is an independent risk factor for LRTI is unknown. This study estimated the risk of LRTI-related hospitalization among late preterm infants with a history of RDS. The population-based cohort from Québec included all late preterm infants (32-36 weeks gestational age) born in 1996 to 1997. RDS was identified by International Classification of Diseases, Ninth Revision code 769, and a comparison cohort generated from all without RDS. A multivariable model estimated the adjusted odds ratio of LRTI-related hospitalization among late preterm infants with a history of RDS; and the incidence and increased risk of childhood chronic respiratory morbidity was calculated. Of the 7488 late preterms, 459 (6.1%) had a history of RDS; 525 late preterms (7.0%) were hospitalized for LRTI in infancy, including 57 (12.4%) with RDS. The adjusted odds ratio for LRTI-related hospitalization associated with RDS was 1.6 (1.2-2.2). Other significant risk factors included male sex, or diagnosis of other respiratory conditions, diaphragm anomalies, bacteremia, intraventricular hemorrhage, congenital heart disease or respiratory system anomalies. Late preterm infants with a history of RDS were also at a significantly increased risk of childhood chronic respiratory morbidity. Late preterms with a history of RDS are at a 60% increased risk of LRTI-related hospitalization in infancy compared with late preterm infants without RDS. Such infants may benefit from interventions decreasing the risk of contracting respiratory viruses causing acute LRTI.

STANDARD EPIDEMIOLOGICAL CASE DEFINITION AND RISK FACTORS OF NOSOCOMIAL PNEUMONIA TERM AND PRETERM INFANTS

Based on the results of studying the frequency of clinical and laboratory symptoms single standard epidemiological estimate of pneumonia is designed to be possible to be used with respect to full term and preterm infants. Such estimate should include the presence of inflammatory reaction in the lung on chest radiograph and at least one of the symptoms such as apnea, wheezing, sputum. For term infants the leading risk factor for nosocomial pneumonia associated with neonatal departments at Children ’s Hospital, was established to be a long-term (over 5 days) mechanical ventilation. For preterm newborns the risk factor for pneumonia, in addition, may be a history of respiratory distress syndrome, pneumopathy, intrauterine growth retardation, amniotic fluid aspiration and asphyxia at birth.

Evaluation of Risk Factors for Postoperative Prolonged Intubation in Premature Infants After Cryotherapy for Retinopathy of Prematurity

Premature infants are more prone to cardiorespiratory complications after surgery than term infants. Risk factors for postoperative apnea include post-conception age, gestational age, postnatal age, birth weight, history of respiratory distress syndrome, bronchopulmonary dysplasia, anemia, necrotizing enterocolitis, use of opioids or nondepolarizing muscle relaxants, aminophylline use, history of apnea, body weight at operation, and pre-existing disease. The aim of this study was to identify the most important factors associated with postoperative extubation and respiratory outcomes among premature infants undergoing cryotherapy for retinopathy of prematurity (ROP). We retrospectively analyzed the clinical records of 62 premature infants, with mean +/- standard deviation gestational age of 26.4 +/- 2.3 weeks, birth weight of 914.8 +/- 208.5 g, postconception age of 37.0 +/- 2.8 weeks, and body weight at the time of operation of 1970.0 +/- 446.8 g, who underwent cryotherapy for ROP. Only 17 infants were successfully extubated within 2 hours after operation. The most predictive factor for successful or unsuccessful extubation was body weight at the time of operation. Body weight at the time of operation was the most important factor associated with postoperative ventilatory support among premature infants under-going cryotherapy for ROP.

Impact of airway obstruction on lung function in very preterm infants at term*

Morbidity and mortality in preterm infants is significantly determined by the development of pulmonary complications. We thus investigated the impact of obstructive ventilatory disorders on lung function in very preterm infants with a history of respiratory distress syndrome and/or bronchopulmonary dysplasia using repeated body plethysmographic measurements before and after bronchodilation. Lung function, including effective airway resistance (Raw), specific conductance (SGaw), functional residual capacity (FRCbox), and total respiratory system compliance (Crs, multiple occlusion technique) was assessed in 27 preterm infants pound31 wks gestational age at a median postmenstrual age of 38 wks after mild oral sedation before and after inhalation of nebulized salbutamol (1.25 mg/2.5 mL; PARI JuniorBOY N) using the MasterScreen Baby Body (Jaeger, Hoechberg, Germany). In preterm infants median Raw was initially found to be within the normal range as determined for healthy term newborns, but decreased significantly after administration of salbutamol; SGaw changed accordingly. FRCbox was significantly reduced compared with healthy term newborns (16.6 vs. 19.6 mL/kg, mean) and decreased further after bronchodilation, whereas Crs was not significantly altered. This is the first report quantifying the important impact of obstructive ventilatory disorders on lung function in very preterm infants at term. Besides its important role in preterm lung function consecutive overinflation could furthermore be shown to mask reduction of lung volume in these infants. Thus, body plethysmographic measurements seem to be an important diagnostic tool in preterm infants at term before hospital discharge in order to quantify ventilation disorders and to define therapeutic strategies.

Pacifier stiffness alters the dynamics of the suck central pattern generator

Variation in pacifier stiffness on non-nutritive suck (NNS) dynamics was examined among infants born prematurely with a history of respiratory distress syndrome. Three types of silicone pacifiers used in the NICU were tested for stiffness, revealing the Super Soothie® nipple is 7 times stiffer than the Wee Soothie®or Soothie® pacifiers. Suck dynamics among 20 preterm infants were subsequently sampled using the Soothie® and Super Soothie® pacifiers during follow-up at approximately 3-months of age. ANOVA revealed significant differences in NNS cycles/min, NNS amplitude, NNS cycles/burst, and NNS cycle periods as a function of pacifier stiffness. Infants modify the spatiotemporal output of their suck central pattern generator when presented with pacifiers with significantly different mechanical properties. Infants show a non-preference to suck due to high stiffness in the selected pacifier. Therefore, excessive pacifier stiffness may decrease ororhythmic patterning and impact feeding outcomes.

Localized persistent interstitial pulmonary emphysema presenting as a spontaneous tension pneumothorax in a full term infant

Persistent interstitial pulmonary emphysema (PIPE) is a syndrome characterized by air-leakage in the perivascular tissues of the lung, primarily affecting mechanically ventilated neonates. Reports in the literature of infants developing PIPE with no history of respiratory distress syndrome (RDS) or mechanical ventilation are scarce. Here, we present a case of a 3-month-old former full term male infant with no history of RDS or mechanical ventilation who presented with focal cystic lung disease associated with spontaneous tension pneumothorax. He was ultimately found to have PIPE based on pathologic evaluation of the resected cystic region. We believe that focal PIPE should be included in the differential diagnosis of cystic lung disease in a full term, unventilated infant, even when spontaneous pneumothorax is the presenting entity.

Abstract

During periods of regular breathing, heart rate is slower and more variable in healthy (no history of respiratory distress syndrome) prematurely born infants with persistent apnea, relative to full-term control infants of comparable post-conceptional ages. We tested the hypothesis that the cardiovascular differences may be linked to the persistent apnea, rather than premature birth, by assessing heart rate and variability in full-term infants with persistent apnea. Thus, resting heart rate and variability were compared in full-term infants with apnea of infancy, prematurely born infants with persistent apnea, and full-term control infants. Full-term infants with persisting apnea showed slower heart rates than control infants, beginning at 4 months after birth, and enhanced heart rate variability beginning at 6 months. Healthy prematurely born infants with persistent apnea showed cardiovascular alterations similar to those of full-term infants with apnea; these alterations differed from those observed in very premature infants with histories of respiratory distress. The postnatal development of cardiovascular aberrations in infants with persistent apnea suggests that mechanisms accompanying apneic events may contribute to long-term alterations in autonomic control.

Developmental patterns of heart rate and variability in infants with persistent apnea of infancy.

During periods of regular breathing, heart rate is slower and more variable in healthy (no history of respiratory distress syndrome) prematurely born infants with persistent apnea, relative to full-term control infants of comparable post-conceptional ages. We tested the hypothesis that the cardiovascular differences may be linked to the persistent apnea, rather than premature birth, by assessing heart rate and variability in full-term infants with persistent apnea. Thus, resting heart rate and variability were compared in full-term infants with apnea of infancy, prematurely born infants with persistent apnea, and full-term control infants. Full-term infants with persisting apnea showed slower heart rates than control infants, beginning at 4 months after birth, and enhanced heart rate variability beginning at 6 months. Healthy prematurely born infants with persistent apnea showed cardiovascular alterations similar to those of full-term infants with apnea; these alterations differed from those observed in very premature infants with histories of respiratory distress. The postnatal development of cardiovascular aberrations in infants with persistent apnea suggests that mechanisms accompanying apneic events may contribute to long-term alterations in autonomic control.

Epidemiology of neonatal chronic lung disease in Japan.

A nationwide survey on the epidemiology of chronic lung disease (CLD) of the newborn was conducted. Questionnaires were sent to 391 level II and III neonatal centers in Japan and the registration of infants born in 1990 with chronic lung disease was requested. CLD was defined as an oxygen requirement greater than that obtainable in room air at 28 days after birth, with symptoms of persistent respiratory distress and a hazy or emphysematous and fibrous appearance on chest X-ray. A total of 301 neonatal centers (77.0%) responded and 50,290 infants at these centers were registered. Of these, 97% survived the first month and 1,135 of 48,762 neonatal survivors developed CLD. The mortality of infants with CLD was 6.2%. Survival rates at 28 days of age increased consistently with birthweight. Survival at 28 days of age in infants below 1,000 g at birth was 73.7%, but the rate was 93.9% in infants weighing 1,000-1,499 g. The incidence of CLD was inversely proportional to birthweight. Approximately one quarter of neonatal survivors with a birthweight below 1,500 g and approximately half of extremely small infants ( < 1,000 g) developed CLD. The analysis of CLD infants showed that 28.2% of them had a history of respiratory distress syndrome (RDS) and a typical fibrous appearance on chest X-ray (Type I), while 29.3% also had a history of RDS but had an atypical X-ray appearance (Type II).(ABSTRACT TRUNCATED AT 250 WORDS)

Measurements of pulmonary mechanics prior to the elective extubation of neonates

We measured total respiratory system compliance (CRS) and resistance (RRS) by the passive expiratory flow technique prior to the elective extubation of 61 neonates with a history of respiratory distress syndrome. Successful trials of extubation were characterized by a higher mean value of CRS when compared to trials that led to reintubation (1.52 vs. 1.10 mL/cm H2O, P = 0.004). Low values of CRS (0.9 mL/cm H2O or less) were invariably associated with extubation failure, whereas high values of CRS (1.3 mL/cm H2O or greater) were associated with extubation success in 94% of patients. A higher mean value of RRS was recorded in the group of infants who failed extubation when compared to those who were successful (0.22 vs. 0.17 cm H2O/mL/s, P = 0.042). We propose that measurements of pulmonary mechanics, particularly CRS, may be useful in identifying infants who will be at risk for extubation failure.

Halothane anesthesia in infancy: Identification and correlation of preoperative risk factors with intraoperative arterial hypotension and postoperative recovery

Infants are well known to be sensitive to the myocardial depressant effects of halothane. In this study of more than 300 infants, 0 to 24 weeks of age, who received halothane anesthesia, preoperative risk factors were correlated with intraoperative outcome and postoperative recovery. Possible risk factors considered were age, history of respiratory distress syndrome (RDS), preoperative fasting time, and anemia. Intraoperative morbidity was evaluated by occurrence of significant hypotension, slow heart rates, or serious bradycardias. Parameters of postoperative recovery included postanesthetic recovery room admission score, duration of recovery room stay, and time to first feeding. Arterial hypotension occurred with an unexpectedly high frequency of 49.2%. Infants younger than 8 weeks of age (particularly newborns), infants 9-16 weeks of age (fasting eight or more hours), and RDS survivors 0-16 weeks of age were found to be most susceptible to hypotension. Only age and history of RDS, however, proved to be statistically significant risk factors in predicting the probability of intraoperative circulatory depression. Though circulatory depression during halothane inhalation was common, it was not associated with significant intraoperative or postoperative morbidity in terms of cardiorespiratory arrests, serious dysrhythmias, prolonged postanesthetic recovery, or delayed feeding times.