Chest physiotherapy during anesthesia for children with cystic fibrosis: effects on respiratory function.

BACKGROUND: Physiotherapists sometimes use elective surgical procedures for children with cystic fibrosis as an opportunity to perform physiotherapy treatments during anesthesia. These treatments theoretically facilitate direct endotracheal airway clearance and compensate for any post-operative respiratory deterioration related to the anaesthetic and surgery. MATERIALS, PATIENTS, AND METHODS: Children were randomized either to receive physiotherapy or not following anesthesia and intubation. Respiratory mechanics (C(rs) and R(rs)), tidal volume, and peak inspiratory pressure (PIP) were measured immediately before and after physiotherapy. FEV(1) was measured before and after surgery and post-operative physiotherapy requirements were recorded. RESULTS: Eighteen patients, mean age 12 years (range 2.8-15 years) were recruited, with nine in each group. Both groups showed a non-significant decline in FEV(1) the day after surgery compared with pre-operative values (-5.8%: physiotherapy and -7.1%: control). Both PIP and R(rs) increased significantly following physiotherapy (within- and between-groups, P < 0.05). In addition, there was a significant within-group reduction in C(rs) after physiotherapy which approached significance between-groups (P = 0.07). There were no significant within- or between-group differences in tidal volume following treatment in either group. CONCLUSION: The unanticipated decline in respiratory function immediately following physiotherapy was short-lived and not discernible in longer term outcomes measured by FEV(1) or physiotherapy requirements post-operatively. If respiratory physiotherapy under anesthesia is considered necessary and the benefits of removing secretions are deemed to outweigh the short-term risks, it may be necessary for the anaesthetist to consider modifying ventilatory support to counteract any short-term negative effects of the treatment.

Thermographic Microstructure Monitoring in Electron Beam Additive Manufacturing.

To reduce the uncertainty of build performance in metal additive manufacturing, robust process monitoring systems that can detect imperfections and improve repeatability are desired. One of the most promising methods for in situ monitoring is thermographic imaging. However, there is a challenge in using this technology due to the difference in surface emittance between the metal powder and solidified part being observed that affects the accuracy of the temperature data collected. The purpose of the present study was to develop a method for properly calibrating temperature profiles from thermographic data to account for this emittance change and to determine important characteristics of the build through additional processing. The thermographic data was analyzed to identify the transition of material from metal powder to a solid as-printed part. A corrected temperature profile was then assembled for each point using calibrations for these surface conditions. Using this data, the thermal gradient and solid-liquid interface velocity were approximated and correlated to experimentally observed microstructural variation within the part. This work shows that by using a method of process monitoring, repeatability of a build could be monitored specifically in relation to microstructure control.

Tracheal extubation of the neonate at 2 to 3 cm H2O continuous positive airway pressure.

To investigate the efficacy of extubation at higher levels of continuous positive airway pressure (CPAP), 49 newborns (0.95 to 4.0 kg) were extubated at 2 to 3 cm H2O following 1 to 47 days of CPAP therapy. Pre- and postextubation measurements of Po2, PCO2, pH, FiO2, and CPAP were made in all infants. No significant differences (P less than.05) were found between pre- and post-extubation arterial blood gas values for all patients. Comparison of pre- and post-extubation blood gas data with respect to birthweight (less than 2.0 kg vs greater than 2.0 kg) and intubation time (less than 8 days vs. greater than 8 days) also indicated no statistical differences. Mean alveolar-arterial oxygen differences and FiO2 for 41 infants showed progressive decreases following extubation. Six of the 49 infants required reintubation within 72 hours following extubation. The results of this study indicate that newborns with respiratory disease requiring CPAP may be extubated at 2 to 3 cm H2O with no significant changes in arterial blood gas values, thus preventing prolonged intubation associated with weaning to 0 cm H2O CPAP.

Pulmonary hypertension in the perinatal aspiration syndromes.

Ten patients clinically diagnosed as having perinatal aspiration syndromes were found to have pulmonary hypertension. These infants were either term or postmature babies and had the following characteristics: (1) systemic or suprasystemic levels of pulmonary artery pressure (range, 50 to 117 mm Hg); (2) a degree of pulmonary hypertension not related to the degree of aspiration evident on chest roentgenograms; (3) evidence of right-to-left shunting at the ductal or foramen ovale level; and (4) sustained severe hypoxemia despite 100% inspired oxygen concentration. The overall mortality for the group was 50%. Since these patients had marked clinical and physiologic similarities to patients previously reported as having the persistent fetal circulation syndrome (PFC), they were classified as having "PFC with aspiration." The existence of pulmonary hypertension should be suspected despite roentgenographic evidence of aspiration in any patient who also manifests the clinical characteristics of PFC because its treatment may alter the prognosis of such patients.

Desquamative interstitial pneumonia and antigen-antibody complexes in two infants with congenital rubella.

Desquamative interstitial pneumonia was observed in two infants with the late-onset congenital rubella syndrome. In both infants this unusual lung disease was associated with circulating immunoglobulin M complexes and interstitial pulmonary deposits of IgM by immunofluorescence. Both infants had IgG deficiency. The first child recovered with a reduction in IgM complex levels and synthesis of rubella-specific IgG. The second infant died during the acute phase of his illness at which time there were high serum concentrations of IgM complexes and slightly increased levels of IgG complexes. Delayed maturation of the immune response in congenital rubella may predispose to persistent antigenemia and pulmonary deposition of rubella antigen-containing IgM complexes resulting in an acute form of interstitial pneumonia.

The role of the laboratory in the diagnosis of cystic fibrosis.

Laboratory investigations used for detecting cystic fibrosis have been critically reviewed. The sweat test is still the only investigation that can be used for detecting the disease at any age. Trypsin in blood or serum might have the same discriminatory power during the first three months of life and could be used for neonatal screening. There is no immediate prospect for prenatal diagnosis or heterozygote detection. The change of the pattern of plasma proteins in cystic fibrosis is the same as in other chronic disorders with varying clinical intensity. Albumin and alpha-1-antitrypsin may be used to monitor treatment. The plasma concentration of alpha-2-macroglobulin is considerably decreased in many younger patients.

Palmitic acid concentrations and lecithin/sphingomyelin ratios in amniotic fluid.

Palmitic acid concentrations and L/S ratios have been estimated in amniotic fluid specimens with and without centrifugation and cold acetone precipitation. Although the number of cases was small, both of these measurements in uncentrifuged fluid seemed to reflect only indirectly on lung maturation in normal pregnancy while with centrifuged fluid the L/S value predicted RDS in one infant more reliably than palmitic acid concentration.

Idiopathic interstitial pneumonitis in children: a national survey in the United Kingdom and Ireland.

Interstitial lung disease (ILD) of unknown etiology in immunocompetent patients is rare in children. A national survey was carried out in the United Kingdom and Ireland over a 3-year period in order to identify prevalence, age distribution, histopathology, natural history of the illness, and response to current treatment.Forty-six cases were identified, including 29 males and 17 females. Seventy-six percent presented in the first year of life. Nine (16%) occurred within four families. Conventional treatment with pulsed methylprednisolone, prednisolone, or hydroxychloroquine, singly or in combination, resulted in an excellent response in 65% of cases. Seven children died (15%). The recurrence risk for further children within the same family to develop ILD is estimated to be approximately 10%. The prevalence rate of this condition in the United Kingdom and Ireland during the period of study for children aged 0-16 years is estimated to be 3.6 cases/million.

Fibrosing alveolitis and desquamative interstitial pneumonitis.

We report the experience with and evaluation of treatment strategies in fibrosing alveolitis and desquamative interstitial pneumonitis (FA/DIP) over the last 16 years by a review of all cases referred to a tertiary referral center. There were 25 cases, 16 boys and 9 girls (mean age at onset, 2.3 years; range, 7 days to 11.6 years). In each case the diagnosis was confirmed by open lung biopsy at a mean age of 3.3 years (range, 7 weeks to 15.1 years). Presently features were tachypnea (19), cyanosis (15), cough (12), exertional dyspnea (7), recurrent chest infections +/- wheezing (9), and clubbing (8). Four patients recovered without antiinflammatory medication. The others received specific treatment. Of 11 patients given only prednisolone, six improved, two did not, and three died despite treatment. Of five patients receiving only chloroquine, four responded. Five patients received both prednisolone and chloroquine; one died, two responded well. There was poor progress in the remaining two. Of the 10 patients receiving chloroquine six (60%) showed a good response. A younger presentation carried a worse prognosis, but chest radiology at presentation and outcome were not interrelated. Those with mild histological changes all survived, but severe desquamation or fibrosis at biopsy was not related to outcome. In four cases there was a family history (16%). Patients with FA/DIP probably represent a disease spectrum of multiple etiology with a variable prognosis and response to treatment.

Pulmonary alveolar microlithiasis in childhood: diagnosis by transbronchial biopsy.

A 7-year-old girl of Arabic origin by consanguineous parents presented with a miliary pattern on chest x-ray. Transbronchial lung biopsy revealed a histological diagnosis of pulmonary alveolar microlithiasis, a condition rarely described in childhood. This report highlights the clinical and radiological features, documents the transbronchial lung biopsy as a useful diagnostic procedure, and suggests a possible genetic etiology with autosomal recessive inheritance.

Primary pulmonary lymphangiectasis in a premature infant: resolution following intensive care.

Primary pulmonary lymphangiectasis is a rare disease, often described as fatal within the neonatal period. We report on an infant who developed severe bilateral chylous pleural effusions with computed tomography (CT) features of pulmonary lymphangiectasis. She recovered spontaneously with supportive treatment only. We discuss aspects of her intensive care which might have contributed to the good outcome, and conclude that modern intensive care may allow spontaneous recovery in conditions described in the literature as having a very poor outcome.

Generalized lymphangiomatosis and chylothorax in the pediatric age group.

Four patients with generalized lymphangiomatosis presenting with chylothoraces are described. All four had bone involvement, two had involvement of the spleen, and one of the pericardium. The diagnosis was confirmed by typical radiology, histology, and in three patients by immunohistochemistry. Treatment was mainly palliative. Three patients died within 1/2 to three years of presentation.

A step in the right direction: assessing exercise tolerance in cystic fibrosis.

Exercise tolerance may be reduced in patients with cystic fibrosis, but it is not always possible to predict this from standard lung function measurements. Formal exercise testing may, therefore, be necessary, and the test should be simple and readily available. We have developed a "3-minute step test" and compared it with the standard 6-minute walking test. Subjects stepped up and down a 15-cm-high single step at a rate of 30 steps per minute for 3 minutes. The effect of the step test on spirometry was tested first in 31 children with CF (mean age, 12.0 years), who had a mean (range) baseline forced expired volume in 1 second (FEV1) of 64% (18-94%) of predicted values. The step test was then compared with the standard 6-minute walk in a further 54 patients with cystic fibrosis (mean age, 12.5 years), with mean (range) baseline FEV1 of 61% (14-103%) of predicted values. Outcome measures were minimum arterial oxygen saturation (SaO2), maximum pulse rate, and the modified Borg dyspnea score. Post-step test spirometry showed mean (95% CI) changes of -1.1% (-6.0 + 3.9%) for forced vital capacity, of -1.6% (-4.2 + 1.1%) for FEV1, and +0.25% (-2.8 + 3.3%) for peak expiratory flow, although 5/31 children showed >15% drop in one or more parameters. The step and walk tests both produced significant changes (P < 0.0001) in all outcomes, with a mean (range) minimum SaO2 of 92% (75-98%) versus 92% (75-97%), a maximum pulse rate of 145 b.p.m. (116-189) versus 132 (100-161), and a Borg score of 2.5 (0-9) versus 1.0 (0-5), respectively. Comparison of the two tests showed that the step test increased breathlessness (mean change Borg score, 2.3 vs. 0.8; P < 0.0001) and pulse rate (mean change, 38% vs. 24%, P < 0.0001) significantly more than the walk, whereas the decrease in SaO2 was similar (mean change, -2.9% vs. -2.6%; P = 0.12). Some patients with a significant drop in SaO2 (>4%) would not have the decrease predicted from their baseline lung function. Reproducibility for the two tests was similar. The step test is quick, simple and portable, and is not dependent on patient motivation. Although the step test is more tiring, its effect on SaO2 is similar to the 6-minute walking test. It is a safe test that may prove to be a valuable measure of exercise tolerance in children with pulmonary disease, although longitudinal studies are now needed.

Successful surgical treatment of tracheal compression following right pneumonectomy in infancy. Long-term follow-up.

Two patients (aged 10 and 16 months) underwent right pneumonectomy: one for an oesophageal bronchus, the other for a hypoplastic right lung with sequestration. Both patients subsequently developed severe stridor. The heart rotated to the right and the aortic arch compressed the trachea. This unusual vascular compression was treated by a bypass graft between the ascending and descending aorta and division of the aortic arch between the left carotid and left subclavian artery at the age of 5 years and 4 months, and 20 months respectively. The postoperative recovery was uneventful in the first patient. The second patient required 7 weeks of ventilatory support. Both patients are well (14 and 7 years after surgery). Cardiac catheterisation and angiography in the first patient and Doppler echocardiography in the second demonstrated unrestricted flow through the graft into the descending aorta. Pulmonary function studies showed a restrictive defect with some obstruction in both children. Despite this finding, both patients enjoy a normal life with some sporting activities. The long-term results suggest the effectiveness of this procedure in the treatment of this rare but severe complication of pneumonectomy in infancy.

Disordered breathing during sleep in patients with mucopolysaccharidoses.

OBJECTIVE: Obstructive sleep apnoea (OSA) has been reported as a feature of children with mucopolysaccharidoses (MPS). However, the incidence and severity of OSA with respect to disease type is poorly defined. The aim of the present study was to measure objectively the degree of OSA in a group of children with a range of MPS syndromes. METHODS: In a cross-sectional study, cardiopulmonary sleep studies were performed during unsedated sleep in 26 children with MPS over a period of 2 years. Scores of OSA severity based upon clinical history and upon objective sleep study data were made in each case and compared. RESULTS: OSA was present in 24/26 patients, and ranged in severity from mild to severe. OSA was most marked in MPS type IH (Hurler syndrome) followed by types IHS (Hurler--Scheie syndrome) and II (Hunter syndrome). Frequent arousals and poor sleep quality, not suspected clinically, were noted in several patients. There was agreement between the clinical and objective scoring systems in only 17/26 patients (65%) with clinical history scores tending to underestimate the most severe cases (5/26 cases) and overestimate the severity in the mild cases (4/26 cases). CONCLUSIONS: Obstructive respiratory problems are frequent in MPS patients and there are differences in severity of OSA between the different MPS types. Assessments of the severity of OSA based upon clinical history alone are inadequate. Our results suggest that objective sleep studies are necessary to evaluate these cases, to monitor clinical outcome and to assess the effects of therapeutic intervention. Prospective studies in larger numbers of patients are needed to validate these observations.

Quit rates at one year follow-up of Alaska Native Medical Center Tobacco Cessation Program.

The prevalence of tobacco use in the Alaska Native population is unusually high, as high as 50% in both adult men and women. In June of 1992, the Alaska Native Medical Center and the Alaska Area Native Health Service began a tobacco cessation program using behavioral modification classes and transdermal nicotine patches. Patients were subsequently followed at three month intervals for a year to assess smoking status. To date, 193 people have completed the program with at least three months having elapsed since completion of classes. The quit rates at three, six, nine, and twelve months were 31%, 30%, 24%, 21% respectively. The long-term quit rates for this tobacco cessation program are comparable to the rates of other studies which have included both behavioral modification and transdermal nicotine.