Tracheobronchial abnormalities in infants with bronchopulmonary dysplasia

Twelve preterm infants with bronchopulmonary dysplasia underwent bronchoscopy to determine if airway abnormalities were contributing to persistent pulmonary problems. Indications for bronchoscopy were persistent atelectasis, lobar hyperinflation, or both on chest radiograph (11 patients), unexplained respiratory distress (three patients), and aspiration of tissuelike material from a tracheostomy (one patient). Bronchoscopy revealed abnormalities of the trachea, bronchi, or both in all infants, including partial or near total airway occlusion by abnormal growth of tissue (10 patients); tracheomalacia, bronchomalacia, or both (three patients); and inspissated secretions (two patients). Seven infants died during initial hospitalization. Tracheobronchial abnormalities should be considered as a cause of persistent pulmonary problems in infants with bronchopulmonary dysplasia.     

Pulmonary hypertension in infants with bronchopulmonary dysplasia

Seventeen children with oxygen-dependent bronchopulmonary dysplasia, right ventricular hypertrophy, and Doppler echocardiographic evidence of pulmonary hypertension were studied by cardiac catheterization. Fifteen of these patients had pulmonary hypertension when placed in room air; six of these 15 patients were shown to have large systemic-to-pulmonary collateral vessels. The hemodynamic responses to oxygen and hydralazine were evaluated. Five patients developed normal pulmonary artery pressure while receiving supplemental oxygen and were not studied further. Of the remaining ten patients, the six patients with large, hemodynamically significant collateral vessels all had deleterious reactions to hydralazine. Two of the four patients without collateral pulmonary circulation responded to hydralazine with further reductions in mean pulmonary artery pressure. Five of the ten patients who had persistent pulmonary hypertension while receiving oxygen have died. Cardiac catheterization and angiography may provide important diagnostic, therapeutic, and prognostic information in patients with pulmonary hypertension complicating bronchopulmonary dysplasia.     

Antireflux surgery in infants with bronchopulmonary dysplasia

We reviewed the medical records of nine infants with severe bronchopulmonary dysplasia and gastroesophageal reflux who underwent fundoplication-gastrostomy surgery. All the infants were born prematurely, required preoperative mechanical ventilation, and were failing to thrive. The operative procedure was well tolerated by all the infants. Seven patients were extubated by day 11, and two patients required long-term ventilation. There were two postoperative deaths, both attributed to acute respiratory deterioration followed by cardiorespiratory failure. The postsurgical respiratory response was observed to be a rapid decrease in oxygen requirements and an absence of further aspiration episodes. A mean decrease of 0.14 in fractional inspired oxygen concentration was noted by 30 days postoperatively, and by 180 days the decrease in fractional inspired oxygen concentration was 0.22. All infants were fed by gastrostomy by postoperative day 4, with no evidence of clinical reflux. The nutritional response was noted to be an increase in growth velocity with increasing age (ie, catch-up growth) and ease of feeding. At both 30 and 180 days postoperatively, the mean growth velocity was more than double the preoperative growth velocity. In addition, ease of postoperative feeding reduced the nursing care requirements and allowed earlier discharge from hospital. Fundoplication and gastrostomy is effective in facilitating growth and feeding in addition to decreasing oxygen requirements in infants with severe bronchopulmonary dysplasia and gastroesophageal reflux.     

Weaning oxygen in infants with bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a form of chronic lung disease commonly seen in preterm infants as the sequelae following respiratory distress syndrome. The management of evolving BPD aims to minimise lung injury and prevent the impact of hypoxia and hyperoxia. Proposed morbidities include respiratory instability, pulmonary hypertension, suboptimal growth, altered cerebral oxygenation and long-term neurodevelopmental impairment. The ongoing management and associated morbidity present a significant burden for carers and healthcare systems. Long-term oxygen therapy may be required for variable duration, though there is a lack of consensus and wide variation in practise when weaning supplemental oxygen. Furthermore, a shift in care towards earlier discharge and community care underlines the importance of a structured discharge and weaning process that eliminates the potential risks associated with hypoxia and hyperoxia. This review article describes recent evidence outlining oxygen saturation reference ranges in young infants, on which structured guidance can be based.     

Systemic hypertension in infants with bronchopulmonary dysplasia

Thirteen of 30 infants with bronchopulmonary dysplasia demonstrated systolic blood pressure readings above 113 mm Hg on at least three separate occasions. In contrast, only one of 22 infants without BPD developed hypertension. The onset of hypertension often followed discharge from the nursery, was transient, and responded well to antihypertensive medication. Its significance is exemplified by the presence of left ventricular hypertrophy in three infants and a cerebrovascular accident in one child. We conclude that systemic hypertension is a significant problem in infants with BPD, and recommend close monitoring of blood pressure during their follow-up care.     

Pulmonary and renal responses to furosemide in infants with stage III-IV bronchopulmonary dysplasia

Pulmonary and renal responses to furosemide were evaluated in ten infants with stage III-IV bronchopulmonary dysplasia. Furosemide was given intravenously for two doses, 1 and 2 mg/kg, at approximately 24-hour intervals. The following indices were evaluated in series before and after entry into study: clinical respiratory distress syndrome score; blood pH; partial pressure of arterial carbon dioxide; alveolar-arterial oxygen gradient; urine output; glomerular filtration rate; fractional excretion of filtered sodium, chloride, potassium, and calcium; osmolar clearance; water clearance; and concentrations of serum electrolytes and calcium. A significant decrease in the respiratory distress syndrome score and in the partial pressure of arterial carbon dioxide was seen only transiently at two hours following each dose. There was no significant improvement in the alveolar-arterial oxygen gradient during the study. Furosemide induced diuresis and urinary excretion of sodium, chloride, potassium, and calcium. A significant decrease in serum chloride and potassium concentrations was seen at 48 hours after entry into study; serum sodium and calcium concentrations remained unchanged. This study has demonstrated that furosemide administration has only a short-term effect in the lung but has a potential for long-term complication on electrolytes and calcium balance in infants with well-established stage III-IV bronchopulmonary dysplasia.     

Long-term morbidity of infants with bronchopulmonary dysplasia

Bronchopulmonary dysplasia occurred in 179 infants discharged from a regional neonatal intensive care unit between 1975 and 1982. Perinatal and outcome factors were compared for these study infants and a group of 112 controls matched for birth weight category and year of birth. There were multiple differences between study infants and controls in demographic, diagnostic, and therapeutic items, all of which were categorized as pulmonary items occurring before and after the development of bronchopulmonary dysplasia, and nonpulmonary items. The postdischarge death rate was 11.2% in infants and 0.9% in control infants (P less than .001). Ongoing morbidity was most marked in the areas of health history, physical examination, growth, and vision. Neurodevelopmental abnormalities and hearing abnormalities occurred slightly more frequently in study infants than in controls but not significantly so. Major developmental abnormalities were less frequent in this population than has been the case in other follow-up studies in this area. This group of infants requires close postdischarge observation because ongoing morbidity and postdischarge mortality, part of which may be preventable, are frequent.     

Management of infants with bronchopulmonary dysplasia in Germany

Although official guidelines for diagnosis and treatment of bronchopulmonary dysplasia (BPD) exist in Germany the practice in tertiary care neonatology centres differs considerably. There is no consensus about the appropriate level of oxygen saturation for infants at risk for BPD or infants with established BPD. Targeting oxygen saturation just below 90% in the first weeks and in the lower nineties thereafter seems to be a reasonable approach. Systemic corticosteroids must be used very restrictively because of adverse short- and long-term outcomes. Diuretics, inhaled corticosteroids, and bronchodilators may be used based on a stringent assessment of the individual response; their routine use cannot be recommended. Domiciliary oxygen is a therapy rarely prescribed in Germany although, if carefully planned and organised, it is safe and effective. Infants with home oxygen need a close follow-up by neonatologists and other specialists. Routine vaccination is recommended from the postnatal age of 3 months onwards.     

Expiratory flow limitation in infants with bronchopulmonary dysplasia

We evaluated lung function in 20 infants with bronchopulmonary dysplasia (BPD) during the first year of life. Compared with a group of age- and size-matched controls, the infants with BPD had a significantly (P less than 0.005) lower functional residual capacity (FRC; 25 +/- 4 vs 18 +/- 6 ml/kg) at less than 10 1/2 months after conception, but no significant difference during the remainder of the first year. The partial expiratory flow volume curves in the infants with BPD were markedly concave, with tidal breathing approaching expiratory flow limitation. The infants with BPD had significantly (P less than 0.01) lower absolute and size-corrected flows than did control infants, and 50% of the infants with BPD required rehospitalization because of acute respiratory distress associated with a lower respiratory tract illness. In addition, the slope of the linear regression of maximal expiratory flow at FRC (in milliliters per second) vs length (in centimeters) was significantly lower (P less than 0.001) for the infants with BPD than for normal control infants (2.25 vs 4.52), indicating poor growth of the airways. Oxygen saturation (SaO2 was negatively correlated with maximal expiratory flow at FRC, indicating that measurement of SaO2 alone may not be sufficient in the evaluation of lung function in infants with BPD. We conclude that, although infants with BPD improve clinically during the first year of life, they have abnormal functional airway growth; the decreased expiratory flow reserve helps to explain their high risk for acute respiratory distress during lower respiratory tract illness.     

Pulse oximetry advantages in infants with bronchopulmonary dysplasia

We studied 12 infants with a clinical and radiologic diagnosis of bronchopulmonary dysplasia who were oxygen dependent and older than 30 days. Simultaneous readings of hemoglobin oxygen saturation (SaO2) determined by two pulse oximeters (Nellcor 100, BTI Biox III) and transcutaneous (tc) PO2 (Sensor Medics, Transend) were correlated with SaO2 (Radiometer, OSM 2 Hemoximeter) and PaO2 (Corning 178) measured on blood from an indwelling arterial catheter. For each infant, the fractional inspiratory oxygen (FiO2) was adjusted to obtain three to five sets of data in the range of 70% to 95% SaO2. Fifty-three data points were generated and pooled for analysis. The slope of the regression line generated for the Nellcor 100 was .86; for the BTI Biox III, it was .91; and for the Sensor Medics Transend, it was .55, resulting in average errors of +2.5%, +1.0%, and -29%, respectively, when comparing corresponding transcutaneous and arterial values. When SaO2 was equal to or less than 95%, no infants were hyperoxic. These data confirm reports by others that tcPO2 values do not accurately represent PaO2 values in older infants with bronchopulmonary dysplasia. Pulse oximeters do not require user calibration, and their sensor is unheated so they will not cause skin burns. We conclude that pulse oximetry offers major advantages over tcPO2 measurements in the management of infants with bronchopulmonary dysplasia.     

Conductive hearing loss in preterm infants with bronchopulmonary dysplasia

OBJECTIVE: To determine the risk of conductive hearing loss in preterm infants with bronchopulmonary dysplasia (BPD) and preterm controls. METHODOLOGY: The study population consisted of 78 infants with BPD of 26-33 weeks gestation and 78 controls of similar gestational age matched for broad-based birthweight categories. An auditory brainstem response (ABR) audiology was performed shortly before hospital discharge. Visual reinforcement orientation audiometry (VROA) and impedance audiometry were performed at 8-12 months corrected for prematurity. Infants with persistent audiological abnormalities were referred for evaluation to paediatric ENT surgeons. RESULTS: Infants with BPD had a significantly higher rate of ABR abnormalities (BPD: 22%, controls: 9%; P = 0.028). On VROA and impedance audiometry, the infants with BPD also had a higher rate of persistent abnormalities. Following ENT assessment, 22.1% of infants with BPD and 7.7% of controls had persistent conductive dysfunction requiring myringotomy and grommet tube insertion (P = 0.03). Most of these infants had normal ABR audiometry at hospital discharge. CONCLUSIONS: Preterm infants with BPD are at high risk of persistent conductive hearing loss late in the first year of life compared to controls. An ABR audiology conducted at the time of hospital discharge does not predict accurately later conductive hearing problems. Infants with BPD should have routine audiological evaluation toward the end of the first year of life.     

新生儿支气管肺发育不良症临床分析

为了解新生儿支气管肺发育不良症( BPD)的发病因素、临床特点,对 17例新生儿 BPD的临床资料进行分析.其中男 13例,女 4例,胎龄( 31.4± 3.4)周,出生体重( 1643± 327) g.结果 17例 BPD原发病中新生儿呼吸窘迫综合征( NRDS) 5例,胎粪吸入性肺炎 1例,肺炎 4例,呼吸暂停 7例.出生后均长时间吸氧、机械通气,平均机械通气时间( 26.8± 9.7) d.病程第( 16.2± 5.6) d,胸片肺部出现囊状透亮区,以后肺呈囊泡样蜂窝样改变.所有病例均并发肺部感染. 9例康复出院, 1例自动出院, 7例死亡. 1例做尸检,光镜下两肺广泛纤维化,成纤维细胞增生,肺泡壁增厚,符合 BPD诊断.提示早产、长时间吸氧、机械通气、反复肺部感染是 BPD的主要发病因素,早产儿机械通气超过 2周要高度警惕发生 BPD.     

Management of infants with bronchopulmonary dysplasia in North America

The in-hospital management of infants with BPD includes minimizing the duration of mechanical ventilation and avoiding the use of high inspired oxygen concentrations while maintaining adequate oxygenation. Fluid restriction, bronchodilators, and diuretic therapy can improve lung function and reduce the need for supplemental oxygen and high ventilator settings, but do not change the ultimate course of these infants. Corticosteroids also improve lung function and accelerate weaning from oxygen and mechanical ventilation, but their use during the first weeks of life is associated with worse neurological outcome. Adequate nutrition plays an important role in lung injury protection and recovery. Infants with severe BPD frequently develop pulmonary hypertension and may benefit from the use of pulmonary vasodilators. Outpatient management must be carefully planned and carried out by experienced multidisciplinary teams. Social and financial issues must be addressed with the family and caregivers. Home oxygen and mechanical ventilation therapy are used frequently after discharge and require specialized staff and equipment. Maintenance of oxygenation and proper nutritional support are critical aspects in the post-discharge management of these infants. Immunizations and RSV prevention are also important to prevent infections in these vulnerable immunocompromised patients.     

Non-furosemide-related renal calcifications in premature infants with bronchopulmonary dysplasia

Renal calcification is a known complication of long-term furosemide therapy in infants with bronchopulmonary dysplasia (BPD). In a prospective study the clinical course and long-term renal sequelae of renal calcifications of 19 consecutive premature neonates (birthweight < 1250 g) with bronchopulmonary dysplasia who did not receive furosemide were examined. Infants were divided into two different groups on the basis of ultrasound evidence of renal calcifications (RC group) or absence of renal calcifications (NRC group). Serial examinations, performed at the age of 1, 2, 3, 6, 9 and 12 months, showed that 12 infants at the mean age of 68.5 ± 12.8 days of life had renal calcifications (63%), and 3 of them had nephrolithiasis; 8 had bilateral renal calcifications. Among the 9 survivors, 2 had chronic renal calcifications at the age of 9 months; however, all normalized at the age of 12 months. Twelve infants received hydrochlorothiazide and spironolactone (63%), 17 had prolonged courses of xanthines and dexamethasone (89.5%), while furosemide was not part of the routine pharmacological administration. Statistical analysis showed that birthweight, gestational age, Apgar score and length of parenteral nutrition were comparable in the RC and NRC group infants. Mean serum creatinine, creatinine clearance, fractional sodium excretion and urinary calcium excretion values during the 12-month study period were comparable in the RC and NRC groups. Mechanical ventilation and hospital stay length were instead associated with renal calcification occurrence. The strongest indicator of renal calcification risk for this high-risk population is the severity of the unresolved acute lung disease, where different facets of respiratory management, other than the addition of furosemide, represent sufficient stimuli and renal injury to potentiate stone formation.