William H. Tooley

Treatment of the Idiopathic Respiratory-Distress Syndrome with Continuous Positive Airway Pressure

Abstract We applied a continuous positive airway pressure to 20 infants (birth weight 930 to 3800 g) severely ill with the idiopathic respiratory-distress syndrome. They breathed spontaneously. Pressure, up to 12 mm of mercury, was delivered through an endotracheal tube to 18 infants and via a pressure chamber around the infants head to two. Arterial oxygen tension rose in all, permitting us to lower the inspired oxygen an average of 37.5 per cent within 12 hours. Minute ventilation decreased with increased continuous positive airway pressure, but this had little effect on arterial carbon dioxide tension, pH, arterial blood pressure and lung compliance. Sixteen infants survived, including seven of 10 weighing less than 1500 g at birth.

Patent ductus arteriosus in premature infants.

Abstract Patent ductus arteriosus (PDA) developed in 17 of 111 premature infants (birth weight 1750 g or less) born during a four-year period (15.3 per cent incidence). During that time we treated 29 such infants, 17 born at our own institution and 12 similar infants transferred from other hospitals. Sixteen of the 29 had cardiac catheterization, 10 had operative closure of the PDA, and 24 survived. When the PDA became evident, 23 infants had no pulmonary disease, were recovering from the idiopathic respiratory-distress syndrome (IRDS) or had chronic lung disease; all survived. In six infants with severe IRDS, onset of PDA was associated with a worsening of the pulmonary status; only one survived. We recommend cardiac catheterization and operative closure of the PDA in neonates when heart failure cannot be controlled medically. The prognosis is good in infants in whom onset of PDA is not associated with progressively worsening IRDS.

Neonatal status and hearing loss in high-risk infants †

Neurophysiologic and behavioral assessments of auditory function were performed on 224 very low birth weight (less than or equal to 1500 gm) infants requiring intensive care in the nursery. The subjects were studied prospectively from 36 weeks to 4 years of age, as available for follow-up. To classify them according to their neonatal status, we applied a principal components analysis to a number of variables representative of the extent of illness and of patient care in early postnatal life. The subjects were then divided into neonatal status quartiles and evaluated for hearing outcome. All those with sensorineural hearing loss fell exclusively into the lowest neonatal status quartile. Sensorineural hearing loss was statistically associated (1) with greater amounts of furosemide administration for longer durations and in combination with aminoglycoside antibiotics and (2) with more episodes of low pH, hypoxemia, or both, higher total bilirubin levels, and substantially lower neonatal status scores. Birth weight, gestational age, highest creatinine level, Apgar score, and aminoglycosides alone were not systematically related to hearing capacity. Subjects in the lowest neonatal status quartile also had a considerably higher incidence of middle ear disorders, characterized by elevated thresholds and prolonged auditory brain stem-response latencies reflective of conductive hearing loss. We conclude that protracted illness and its associated treatment, independently of specific diagnostic categories, constitute important risk factors for permanent hearing loss and for transient hearing loss in early life.

Changes in phospholipid composition of lung surfactant during development in the fetal lamb.

The lung surfactant isolated from pulmonary fluid of fetal sheep changes both in amount and composition during gestation. Total phosphatidylcholine (PC) and its most surface-active components, disaturated PC, are present at very low levels 3-4 weeks prior to term and rise to adult levels 3-4 days before birth. The acidic phospholipids appear with a different time course. Phosphatidylserine reaches elevated levels about 21 days before birth. Phosphatidylinositol begins to increase at about 130 days of gestation. Phosphatidylglycerol is not a component (less than 1%) of the surfactant in this fetal lung fluid. At term, phosphatidylinositol is the major acidic phospholipid found in these fluids.

Surgical Closure of the Ductus Arteriosus in Premature Infants

During a 62-month period patent ductus arteriosus (PDA) was diagnosed in 88 premature infants with birth weights less than 1750 g. Twenty-one of these infants required operative closure of the PDA. Six infants had uncontrolled heart failure without associated pulmonary disease. Fifteen infants had severe idiopathic respiratory distress syndrome (IRDS) and required operation for deteriorating pulmonary function when heart failure developed. Twelve of these 15 infants weighed less than 1250 g at birth. The ductus arteriosus was ligated in 19 patients and was divided in two patients. The six infants without IRDS survived, and four are completely normal. Of 15 infants with IRDS eight had steady improvement in pulmonary function after operation. Three of these eight patients eventually died. In three infants pulmonary function improved slowly and in two patients pulmonary function did not improve after operation; all of these patients eventually died. Two patients died of peritonitis secondary to bowel ischemia. Of the five infants with IRDS who are alive, one is two months of age, two are moderately retarded in psychomotor development, and two, who developed hydrocephalus, are severely retarded. Although operation successfully controls heart failure in premature infants with PDA and IRDS, progressive pulmonary disease and the complications of extreme prematurity pre-empt good results in most of these infants.

Cost effects of surfactant therapy for neonatal respiratory distress syndrome

OBJECTIVE To examine the cost effects of a single dose (5 ml/kg) of a protein-free synthetic surfactant (Exosurf) as therapy for neonatal respiratory distress syndrome, for both rescue and prophylactic therapy. RESEARCH DESIGN Nonblinded, randomized clinical trials of both rescue and prophylactic therapy. Regression analyses were used to control for the independent effects of sex, multiple birth, delivery method, birth weight, and surfactant therapy. SETTING The prophylactic trial was conducted at a university medical center only; the rescue trial also included a tertiary community hospital. PATIENTS Prophylaxis was administered immediately after birth to 36 infants (38 control subjects) with birth weights between 700 and 1350 gm. Rescue therapy was administered at 4 to 24 hours of age to 53 infants (51 control subjects) with established respiratory distress syndrome and birth weights > or = 650 gm (no upper limit). Infants in the prophylactic trial were not eligible for the rescue trial. RESULTS For the rescue trial, there was a

Developmental profiles for the brainstem auditory evoked potential

16,600 reduction in average hospital costs (p = 0.18), which was larger than the cost of the surfactant (

Exercise performance of the survivors of hyaline membrane disease

450 to

Continuous positive airway pressure and pulmonary and circulatory function after cardiac surgery in infants less than three months of age.

900), yielding a probable net savings. For the prophylactic trial, hospital costs were larger for treated infants versus control subjects who weighed less than about 1100 gm at birth and lower for treated infants versus control subjects who weighed more than 1100 gm at birth (p < 0.05). For the prophylactic sample, the result was an average cost per life saved of

Continuous measurements of skin surface oxygen and carbon dioxide tensions in obstructive sleep apnea

71,500. CONCLUSIONS Single-dose rescue surfactant therapy is probably a cost-effective therapy because it produced a lower mortality rate for the same (and probably lower) expenditure. Single-dose prophylactic therapy for smaller infants (< or = 1350 gm) appeared to yield a reduction in mortality rate for a small additional cost. The use of multiple-dose therapy in infants who do not respond to initial therapy may alter the effects described above to either increase or decrease the observed cost-effectiveness of surfactant therapy. Regardless, surfactant therapy will remain a cost-effective method of reducing mortality rates, relative to other commonly used health care interventions.