PubMed HealthSearch

Biomedical subjects

J F Lucey

Publications and source records attributed to J F Lucey.

At least 19 recordsLinked to original sources

Radiographic findings associated with surfactant treatment.

Radiographs of the chest (CXR) were evaluated in 35 of 41 infants enrolled in a randomized controlled trial of modified bovine surfactant extract (Surfactant-TA Tokyo-Tanabe) treatment. Infants between birthweight 1000 and 1500 gm with respiratory distress syndrome requiring mechanical ventilation and an inspired oxygen concentration 0.4 or greater were randomly assigned to either a single intratracheal dose of saline or surfactant-TA prior to 8 hours of age. Radiographs obtained prior to treatment and 24 hours after treatment were reviewed by a radiologist (N.T.G.) without knowledge of treatment group. Evaluation consisted of a score including criteria for inflation of the lungs, density of the lungs, and extent of air bronchograms. Pneumothorax, pulmonary interstitial emphysema, and asymmetric parenchymal involvement were noted as well. No significant difference in CXR scores were noted in the two groups, before or after treatment. There was a greater incidence of pneumothorax and pulmonary interstitial emphysema in the control infants, which supports the role of surfactant in preventing barotrauma. Increased incidence of asymmetric parenchymal involvement was noted in the surfactant-treated infants. Further study of the possibility of drug maldistribution is warranted.

Female

Perinatal intracranial hemorrhage and retinopathy of prematurity: currently nonpreventable complications of premature birth?

There is now considerable evidence that the control of cerebral circulation in sick small infants is sometimes seriously deranged and subject to wide fluctuations during neonatal care. Our current preoccupation with looking at oxygen administration and peripheral arterial oxygen tensions as the only cause of ROP is not likely to be productive. Until we know more about the causes of cerebral blood flow fluctuation, IVH, asphyxia, and their effects on the retinal circulation, we are not apt to make much progress. There is a strong association between retinopathy and IVH in premature infants. With our current knowledge, we are unable to prevent or to treat either IVH or ROP. The public should be better informed that both of these conditions are usually unavoidable complications of premature birth.

Asphyxia Neonatorum

Failure of conventional monitoring to detect apnea resulting in hypoxemia.

In summary, our findings support and confirm the concerns of many investigators that present methods of cardiorespiratory monitoring are inadequate for the detection of many forms of apnea. Nurses underrecord both the frequency and duration of apneic episodes. Bradycardia is an unreliable index of hypoxemia. Thoracic impedance monitors are unreliable because they detect only a fixed duration of respiratory pause and are sensitive to many artifacts unavoidable in a clinical setting. Finally, ineffective breathing patterns such as disorganized breathing, obstructive apnea, and paradoxical breathing are undetectable by thoracic impedance monitoring. We warn against the reliance on heart rate and thoracic impedance monitoring alone for infants with recurrent apnea.

Apnea

Clinical limitations and advantages of transcutaneous oxygen electrodes.

We investigated the clinical use and limitations of the transcutaneous oxygen electrode described by Huch, Lübbers and Huch in 30 sick infants. One hundred and fifty-nine measurements of arterial oxygen tension (PaO2) and transcutaneous oxygen tension (tcPO2) were made. During the comparisons, arterial blood pressures, heart rate thoracic impedance were continuously recorded, skin axillary and environmental temperatures, hematocrit and skin thickness were measureed and the degree of peripheral perfusion noted. Despite a wide range of these variables, values of tcPO2 and PaO2 were similar (slope 0.963). Two groups of infants were identified in whom tcPO2 was lower than PaO2. These were infants receiving an intravascular infusion of tolazoline and infants with mean arterial blood pressures more than 2.5 s.d. below the predicted average value. Both of these situations represent extreme alterations in peripheral blood flow and give important information regarding the limitations of the method. Less extreme alterations in flow caused by mild hypotension, hypothermia, anemia, radiant warmers, and bilirubin lights did not adversely affect the transcutaneous PO2--arterial PO2 correlation. Advantages of transcutaneous oxygen monitoring over more conventional monitoring methods were assessed. We conclude that the transcutaneous oxygen electrode is safe, is easy to use, has few limitations and provides data which can help improve the management of most sick infants.

Blood Gas Analysis

Transcutaneous oxygen monitoring in aminophylline-treated apneic infants.

Transcutaneous PO2 (tcPO2) monitoring offers a new approach to the evaluation of drug effects. We investigated the effect of theophylline on ten premature infants with apnea. Theophylline was administered as aminophylline, 8 mg/kg per rectum every 12 hours for two doses and 4 mg/kg every 12 hours for a total of two or five days (short and long courses). The tcPO2, heart rate (beat-to-beat), and thoracic impedance were continuously monitored during each of three 4-hour study periods: 12 hours before theophylline administration, 12 hours after initiation of theophylline therapy, and 24 to 48 hours after discontinuing the drug's use. Plasma levels were measured by a radioimmunoassay developed in our laboratory. Polygraphic recordings were analyzed without knowledge of treatment for frequency of apneic spells, mean duration of apneas, total duration of hypoxemia (tcPO2 less than or equal to 40 torr), total duration of hyperoxemia (tcPO2 greater than or equal to 100 torr), basal tcPO2, heart rate, and respiratory rate. In each case during theophylline use, cardiorespiratory patterns were altered, respirations were more regular, apneic spells were reduced, PO2 was stabilized with less hypoxia and hyperoxia, and bradycardic episodes were decreased. There was considerable variation in the response of the ten infants and a significant difference in the frequency of return of symptoms between those receiving short-term therapy and those receiving the longer course.

Aminophylline