The persistent parent.

Parental persistence in the diagnosis and treatment of a child's illness can be examined by asking whether it is congruent with the child's morbidity. The relationship between parental persistence and child morbidity always depends on a "first diagnosis" (ie, what is wrong with the child, if anything?). In many instances, a "second diagnosis" (ie, why is the child being brought to you at this time?) should not be overlooked. First and second diagnoses are identical if persistence and morbidity are congruent but are different if they are incongruent. Once incongruent persistence is suspected, the possibility of parental falsification of symptoms must be faced. In patients in whom a second diagnosis must be made, the second diagnosis may be as simple as maternal anxiety or as complex as Munchausen syndrome by proxy. A "persistence algorithm" is presented and illustrated by descriptions of four children referred to a pulmonologist with complaints suggestive of respiratory disease. The approach, as outlined in the algorithm, may have broad pediatric applications.

Frequency spectra of normal breath sounds in childhood.

Clinicians who auscultate the chest of normal children note that the frequency content of their breath sounds appears to vary with age. Because these changes have not been systematically documented before, we recorded and analyzed inspiratory breath sounds in 35 children (0 to 13 years) and five adults (34 to 43 years). Our objective was to determine if the frequency content of normal breath sounds differed with age. Using a Fast Fourier Transform program, we calculated an average amplitude frequency spectrum from the inspiratory portion of the breath sounds of each subject (n = 10 breaths), and we compared the shape of the AFS and the values of selected frequency parameters. We found that the shape of the AFS of the youngest children differed most from the AFS of adults. Three of four selected frequency parameters (F25, F50, F95) differed significantly between children and adults (p less than 0.05), and one parameter (F75) did not (p = 0.11). The F25, F50, and F75 parameters of children (but not F95) were correlated (p less than 0.001) with increasing height and age. These results suggest that differences in the frequency content of the normal breath sounds of children and adults contribute to the differences that clinicians detect during clinical auscultation.

Evaluation of a cystic fibrosis screening system incorporating a miniature sweat stimulator and disposable chloride sensor.

A new sweat test (CF Indicator; Medtronic, Inc.) for cystic fibrosis (CF) features a compact, portable configuration of electrodes that dispense pilocarpine for iontophoresis. A disposable chloride sensor patch absorbs a specified volume of sweat, in which the chloride concentration is immediately determined as less than 40, 40-60, or greater than 60 mmol/L. We assessed the performance of the system in a five-center study, in relation to the clinical diagnosis and to the Gibson-Cooke sweat test (GCST) as a control test. With sweat chloride concentrations of less than or equal to 40 mmol/L defined as normal and greater than 40 mmol/L as indicating persons at risk for CF, the new system showed 91% specificity and 100% sensitivity for CF, as compared with 92.8% and 100%, respectively, for the GCST. When we used sweat chloride concentrations of less than or equal to 60 mmol/L as probably normal and greater than 60 mmol/L as probably indicative of CF, the new system showed a 99.1% specificity and 98.6% sensitivity, vs 97.8% specificity and 97.9% sensitivity for the GCST test. In both procedures, occasionally insufficient sweat was collected, and this appeared related to the age of the subject. We conclude that the new sweat test system is potentially useful in physicians' offices, in clinics, and similar settings.

Benign hemangioendothelioma--a rare type of posterior mediastinal mass in children.

Two infants with benign hemangioendotheliomas of the posterior mediastinum are reported here. The neoplasms did not produce symptoms and were fortuitously discovered by chest roentgenograms. Computed tomography (CT) was useful in delineating the extent of the lesions preoperatively.

Tracheal breath sounds for detection of apnea in infants and children.

Impedance respiratory monitoring is the standard technique for detecting apnea in infants. A miniature microphone/amplifier system has been used to sense breath sounds over the trachea in order to detect both central and obstructive apnea episodes in infants and children. The tracheal microphone has several advantages over other devices that sense airflow (thermistors, CO2 sampling catheters) because it is not easily dislodged during restless sleep. This simple device may be used in monitoring of neonates and infants; it may eventually replace impedance monitoring.

Steam vaporizer injuries.

There were an estimated 656 cases of vaporizer-related injuries seen in hospital emergency departments in 1979. Two cases of burns with respiratory involvement are described. Both children were directly exposed to steam from commercial vaporizers and suffered cutaneous and respiratory burns. These cases emphasize the hazards of steam vaporizers, devices that have no proven therapeutic benefits.

Relationship between response to exercise and allergy in patients with cystic fibrosis.

Responses to treadmill exercise of 36 patients with cystic fibrosis were studied to evaluate their usefulness in identifying those with atopy. Ten of 36 patients with cystic fibrosis (28%) had an abnormal response to exercise but had no more frequent atopic characteristics than those who had normal exercise responses. Response to treadmill exercise alone cannot identify patients with atopic disease among those with cystic fibrosis.

Method for respiratory sound analysis.

A system is described for the analysis of respiratory sounds by means of a dual-channel sound envelope detector and a real-time spectrum analyzer. A three-dimensional spectral analyzer display for frequency, amplitude, and time has been utilized. Respiratory sounds have been observed with intensities up to 0.5 N/m2 and with normal frequencies in the range of 0 to 1.5 kHz. This system can extract useful information from the sounds of respiration, information which is not available by conventional auscultation.

Relationships among digital clubbing, disease severity, and serum prostaglandins F2alpha and E concentrations in cystic fibrosis patients.

Nine patients with cystic fibrosis but without digital clubbing (Group A) were matched, prospectively, by sex and approximate age to 9 cystic fibrosis patients with digital clubbing (Group B) and to 9 normal persons (control subjects). Patients in Group B had significantly (P less than 0.05) lower clinical scores and forced vital capacity than did those in Group A, indicating more severe pulmonary disease in the former; however, other spirometer tests of pulmonary function revealed no differences between Groups A and B. The degree of digital clubbing had significant (P less than 0.05) linear relationships to forced vital capacity (r = -0.73) and clinical scores (r = 0.853) for Groups A and B. Plasma concentrations of prostaglandins F2alpha and E were significantly increased (P less than 0.05) in both Group A (X +/- SE, 0.48 +/- 0.03 and 0.87 +/- 0.10 ng per ml, respectively) and Group B (X +/- SE, 0.68 +/- 0.04 and 1.81 +/- 0.16 ng per ml, respectively) compared to the control group (X +/- SE, 0.14 +/- 0.01 and 0.39 +/- 0.02 ng per ml, respectively). Group B had significantly larger concentrations than did Group A; however, plasma concentrations of prostaglandin 15-keto-13, 14-dihydro metabolite were not different in Groups A and B, and were significantly smaller than in the control group. These studies suggest that the degree of digital clubbing in cystic fibrosis is related to the severity of the pulmonary involvement and that the prostaglandin system may play an important role in this disease.

Correlation of metabolic and chemiluminescent responses of granulocytes from three female siblings with chronic granulomatous disease.

Polymorphonuclear leukocytes (PMNL) from children with atypical chronic granulomatous disease (CGD), their mother and siblings, and normal controls were studied in regard to glycolytic and hexose monophosphate shunt activities in the resting, methylene blue-stimulated, and phagocytizing states. PMNL from the patients with CGD had normal glycolytic and hexose monophophate shunt activities in the resting state and after stimulation with methylene blue. However, stimulation of the hexose monophosphate shunt after phagocytosis was greatly decreased. These data were correlated with studies of both initial rate and integral counts of chemiluminescence. The chemiluminescent response from patients with atypical CGD was also greatly decreased. This decreased response probably reflects a defect in the oxidative destruction of the phagocytized microbe and correlates well with the decreased activity of the phagocytically activated hexose monophosphate shunt. The defect in generation of radical species of oxygen, singlet oxygen, and chemiluminescence by leukocytes from patients with CGD is discussed.

Congenital lobar emphysema: long-term evaluation of surgically and conservatively treated children.

The clinical conditions, roentgenographic findings, and pulmonary function tests of 6 children (mean age, 10.9 years) with surgically treated congenital lobar emphysema (group 1) were compared with those of 5 children (mean age, 10.3 years) with congenital lobar emphysema who had been treated conservatively, i.e., nonsurgically (group 2). At the time of this study, patients in both groups were asymptomatic. Patients in group 1 were surgically treated because of severe respiratory distress in the newborn period, with the exception of one patient, who was eupneic as a newborn and was not operated on until the age of 9 years. Patients in group 2 were eupneic or mildly distressed in the neonatal period and received only conservative treatment. Two patients in group 1 had occasional wheezing and labored breathing, but no patient in group 2 had recurrent respiratory distress. Roentgenographically, at the time of the study, patients in group 1 had generalized overinflation, whereas those in group 2 had only localized overinflation of the involved lobe and minimal compression of remaining lung tissue. Pulmonary function studies in both groups were not significantly different (P greater than 0.05). Both groups had reduced forced vital capacities, large trapped gas volumes, and reduced forced expiratory flows at low lung volumes. Reductions in forced vital capacity were proportional to the unventilated volumes of lung either excised because of congenital lobar emphysema (group 1) or chronically obstructed by congenital lobar emphysema (group 2). These studies suggest that lung growth was not different in these 2 groups and that asymptomatic or midly symptomatic patients do not benefit from surgical treatment.