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M Gappa

Publications and source records attributed to M Gappa.

At least 19 recordsLinked to original sources
PubMed2001

Lung function testing in infants with cystic fibrosis: lessons from the past and future directions.

Despite the increasing awareness of the need to identify early pulmonary changes in cystic fibrosis (CF) noninvasively, the role of lung function testing in infancy and early childhood remains less clear than in older children with CF. The aim of this review is to summarize available data, discuss the information gained from these publications, and put this information into perspective with more recent developments of lung function testing in both infants and older children with CF. While some of the available data have been the foundation of the current level of understanding of respiratory physiology in CF, interpretation of other data has been hampered by differences between centers with regard to the methods and equipment used, patient selection, small number of subjects, and lack of appropriate reference data. A structured multicenter approach based on recently published recommendations for the measurement of lung function in infancy, together with pursuit of recent developments such as assessment of raised lung volume flow volume curves and ventilation inhomogeneity may help to more effectively utilize lung function tests in infants in the future.

Clinical Trials as Topic↗
PubMed2001

Development of progressive pulmonary interstitial and intra-alveolar cholesterol granulomas (PICG) associated with therapy-resistant chronic systemic juvenile arthritis (CJA).

A girl aged 5 years with therapy-resistant chronic systemic juvenile arthritis (CJA) developed progressive fibrosing lung disease. Histology of an open lung biopsy revealed pulmonary interstitial and intra-alveolar cholesterol granulomas (PICG). Since treatment with steroids and immunosuppressive drugs did not prevent progression of lung fibrosis, an experimental treatment with a tumor necrosis factor alpha (TNF alpha) antagonist etanercept was started. Although development of chronic changes in the lung parenchyma could not be prevented, this treatment brought considerable relief and markedly improved the child's physical capacity. By ruling out other causes for development of PICG, we concluded that the primary disease had caused the development of cholesterol granulomata by macrophage activation. We suggest, therefore, that a trial with etanercept in children with otherwise therapy-resistant CJA should be considered, especially if pulmonary complications have developed.

Arthritis, Juvenile↗
PubMed2001

Passive respiratory mechanics: the occlusion techniques.

The aim of this position paper is to define quality control and acceptance criteria for measuring passive respiratory mechanics in infants using the occlusion techniques to ensure that valid results are obtained. These guidelines cover numerous aspects including: 1) terminology and definitions; 2) equipment; 3) data acquisition; 4) data handling and analysis; 5) reporting of results. Adherence to these guidelines should ensure that measurement of passive respiratory mechanics in infants in different lung function laboratories could be performed with an acceptable degree of safety, precision, and reproducibility. This will facilitate multi-centre collection of data and performance of clinical investigations.

Airway Resistance↗
PubMed2001

The bias flow nitrogen washout technique for measuring the functional residual capacity in infants. ERS/ATS Task Force on Standards for Infant Respiratory Function Testing.

The functional residual capacity (FRC) is the most commonly measured static lung volume in infants. It is important for interpreting volume-dependent pulmonary mechanics, e.g. airway resistance, and defining normal lung growth. The bias flow nitrogen washout technique is widely used for measuring FRC because the dead space and circuit resistance are low, making it suitable for small or sick infants. Moreover, data acquisition and calculation are easily programmed for a personal computer. The aim of this paper is to provide recommendations pertaining to equipment requirements, study procedures and reporting of data for functional residual capacity measurements. While measuring the functional residual capacity is regarded as physiologically and clinically important, the accuracy of the measurement is undoubtedly equally important. Hence, the paper also emphasizes factors influencing the accuracy of functional residual capacity measurements independent of equipment requirements. These recommendations represent the "State of the Art" in 2000.

Clinical Protocols↗
PubMed2000

Obstructive airway disease caused by Moraxella catarrhalis after renal transplantation.

We report a case of severe acute obstructive airway disease 2 months after renal transplantation in a 16-year-old patient with Biedl-Bardet syndrome who was transplanted for end-stage renal failure secondary to cystic kidney disease. Symptoms of severe obstructive airway disease developed 2 months after transplantation under immunosuppression with prednisone, azathioprine, and tacrolimus. The patient did not develop signs of infection; progressive shortness of breath remained the only symptom for several weeks. After extensive diagnostic evaluation, bronchoalveolar lavage revealed Moraxella catarrhalis as the single infectious agent. After 3 weeks of appropriate antibiotic therapy, symptoms of obstructive airway disease were completely relieved. This atypical presentation of Moraxella infection in an immunocompromised host represents a rare complication of renal transplantation, especially in young patients. Special aspects such as frequency, diagnosis, differential diagnosis, and management of this rare complication of renal transplantation in a pediatric patient are discussed.

Adolescent↗
PubMed2000

Tidal forced expirations. ERS/ATS Task Force on Standards for Infant Respiratory Function Testing. European Respiratory Society/American Thoracic Society.

The progress of infant lung function testing has been retarded by both the lack of user-friendly, widely available and affordable equipment and the lack of standardized methodology. The European Respiratory Society/American Thoracic Society Task Force on Standards for Infant Respiratory Function Testing was formed in an attempt to address these deficiencies. This document represents the consensus of investigators with vast experience in the measurement of lung function in infants. The present recommendations deal with equipment requirements, study procedures and reporting of data for measurements of forced expiration at end-tidal inspiration. They represent the "state of the art" in 1999. They are not meant to inhibit further developments in this technique. The authors anticipate that these guidelines will be updated regularly as knowledge progresses.

Europe↗
PubMed1999

A genome-wide search for linkage to asthma. German Asthma Genetics Group.

Asthma is among the most frequent chronic diseases in childhood. Although numerous environmental risk factors have already been identified, the basis for familial occurrence of asthma remains unclear. Previous genome screens for atopy in British/Australian families and for asthma in different American populations showed inconsistent results. We report a sib pair study of a sample of 97 families, including 415 persons and 156 sib pairs. Following an extensive clinical evaluation, all participants were genotyped for 351 polymorphic dinucleotide markers. Linkage analysis for asthma identified four chromosomal regions that could to be linked to asthma: chromosome 2 (at marker D2S2298, P = 0.007), chromosome 6 (around D6S291, lowest P = 0.008), chromosome 9 (proximal to D9S1784, P = 0.007), and chromosome 12 (D12S351, P = 0.010). These linkage regions could be reproduced for all loci by analysis of total or specific immunoglobulin E (minimum P values at these regions were 0. 003, 0.001, 0.010, and 0.015, respectively).

Asthma↗
PubMed1999

Pulmonary function at school-age in surfactant-treated preterm infants.

A follow-up study was conducted in 40 children who had been enrolled in a prospective randomized study of exogenous surfactant therapy for respiratory distress syndrome (RDS) (n = 22; S) or placebo (n = 18; P) to determine long-term pulmonary sequelae of surfactant treatment in premature infants with RDS. At follow-up, mean (SD) age was 6.63 (0.18) and 6.55 (0.23) years for S and P, respectively. Complete lung function tests (LFT) were attempted in all patients. Satisfactory data were obtained in 17/22 surfactant-treated and in 12/18 control children. There was no significant difference between groups for any of the parameters measured. Mean (SD) functional residual capacity (FRC) was 92% (16%) and 90% (21%) predicted, mean (SD) airway resistance (R(aw,exp)) was 122% (25%) and 127% (61%), and mean (SD) forced expiratory volume in 1 s (FEV1) was 104% (12%) and 99% (17%) predicted for S and P. Only maximal expiratory flow at 25% vital capacity (L/s) was significantly below the predicted range in S and P groups, with 74% (23%) and 77% (28%), respectively. To test bronchial hyperreactivity, a simple standardized running test was performed: 4 children in S and 5 in P showed a significant response as defined by clinical airway obstruction or changes in FEV1 and/or R(aw), with no significant difference between groups. Although we found no major abnormalities in lung function and no difference between S and P at early school-age, lack of cooperation during lung function tests makes further follow-up necessary.

Adolescent↗
PubMed1997

Effects of salbutamol delivery from a metered dose inhaler versus jet nebulizer on dynamic lung mechanics in very preterm infants with chronic lung disease.

Treatment of chronic lung disease of prematurity requires effective aerosol delivery of different therapeutic agents. Aerosols can be generated by a metered dose inhaler (MDI) or a jet nebulizer. An MDI combined with a spacer device is easier to use and avoids undesirable effects noted in conjunction with jet nebulization. We compared the clinical effectiveness of 200 micrograms (2 puffs) salbutamol delivered from an MDI in conjunction with a valved spacer device (Aerochamber), and 600 micrograms given via jet nebulizer (PariBaby) on 2 consecutive days, the order being randomized. Thirteen spontaneously breathing very preterm infants [mean (SD) gestational age 27.2 (1.8) weeks; birth weight 0.90 (0.34) kg] were studied at a corrected age of 37 (2.3) weeks. Mean (SD) study weight was 1.83 (0.38) kg. Dynamic lung compliance and resistance were determined from measurements of flows, volumes, and transpulmonary pressures, using a pneumotachometer and a small esophageal microtransducer catheter before and 20 min after salbutamol application. Baseline values before salbutamol administration were similar on both occasions: the mean (SD) compliance was 7.7 (3.0) mL.kPa-1.kg-1 pre-MDI plus-spacer and 8.4 (3.1) pre-jet nebulizer; the resistance was 10.4 (4.0) kPa.L-1.s pre-MDI plus-spacer and 9.7 (3.4) pre-jet nebulizer. Following salbutamol, compliance did not change significantly with either MDI plus spacer or jet nebulizer. Resistance fall significantly with MDI plus spacer (mean -2.2; 99.9% CI -0.35, -4.35) and jet nebulizer (-2.4; 99% CI -0.39, -4.42). We conclude that even in small preterm infants 200 micrograms salbutamol via MDI plus spacer improves dynamic resistance as effectively as 600 micrograms via jet nebulizer and may therefore be a preferable mode of aarosol administration.

Administration, Inhalation↗
PubMed1997

Determinants of lung volume in spontaneously breathing preterm infants.

To study the effects of apneic pauses, sighs, and breathing patterns on functional residual capacity (FRC), we measured FRC repeatedly in 48 healthy preterm infants (weight at study 2,042 +/- 316 g [mean +/- SD], postconceptional age 36.6 +/- 2.0 wk), during unsedated sleep using a modified heliox/nitrogen washout technique. Breathing movements and pulse oximeter saturation (SpO2) were recorded throughout and recordings analyzed for the presence of regular and nonregular breathing pattern, apneic pauses, sighs, and desaturations (SpO2 < 90%) during the last 2 min prior to each FRC measurement. FRC was lower during nonregular than during regular breathing pattern (23.3 +/- 7.2 ml/kg versus 26.9 +/- 7.8 ml/kg, p < 0.02); however, this apparent effect of breathing pattern disappeared after controlling the data for apneic pauses. Apneic pauses resulted in a significant decrease in FRC: mean FRC was 20.0 +/- 6.8 ml/kg if measured within 2 min of an apneic pause, 26.0 +/- 6.9 ml/kg if measured after a sigh (p < 0.001), and 24.0 +/- 7.7 ml/kg if there had been neither a sigh nor an apneic pause (p < 0.05). The interval between the apneic pause and the FRC measurement had no effect on FRC. There was an inverse correlation between FRC and the speed with which SpO2 fell during desaturation (r = -O.5, p < 0.03). Apneic pauses resulted in a persistent reduction in FRC in these preterm infants. Sighs appeared to restore FRC. The significant relationship between FRC and the speed of desaturation found in this study underscores the importance of endogenous or exogenous strategies that help to increase FRC, such as sighs or the application of continuous positive airway pressure, for the stability of oxygenation in preterm infants who have difficulty maintaining their oxygenation.

Female↗
PubMed1996

A new microtransducer catheter for measuring esophageal pressure in infants.

Measurement of esophageal pressure, as a reflection of pleural pressure, is essential for assessment of dynamic lung mechanics in neonates and infants. Conventionally, an esophageal balloon or a fluid-filled catheter is used, but considerable skill is required to obtain accurate results. Both devices have problems, and failure to achieve valid occlusion tests have been reported, particularly in small infants with lung disease. Recently, a flexible #3 French gauge (FG) microtransducer catheter (MTC, Dräger Netherlands) has become available for medical monitoring. We have assessed the accuracy and feasibility of using this device for measuring lung mechanics in 51 spontaneously breathing infants and small children aged 1 day to 24 months (weight 1.35 to 12.0 kg), 9 of whom were healthy neonates, the remainder suffering from a variety of cardio-respiratory diseases, and in 18 sick ventilated infants (weight 0.6 to 4.0 kg). Positioning of the catheter was well tolerated by all infants. The ratio of esophageal to airway opening pressure changes (delta Pes:delta Pao) ranged from 0.94 to 1.09 [mean (SD) 1.013 (0.03)] for the spontaneously breathing infants and from 0.98 to 1.06 [mean (SD) 1.003 (0.02)] In the ventilated infants with no significant difference in this ratio between the two groups (p = 0.16). This new generation of catheter tip pressure transducers may provide a simpler and more reliable tool for assessing transpulmonary pressure changes in infants than has previously been available.

Catheterization↗
PubMed1996

Comparison of heliox and oxygen as washing gases for the nitrogen washout technique in preterm infants.

The nitrogen washout technique usually involves exposure of the patient to 100% oxygen for several minutes. This may be dangerous in preterm infants who are at risk of retinopathy of prematurity (ROP). We wanted to know whether heliox (79% He, 21% O2) can be used instead of oxygen when determining functional residual capacity (FRC). FRC measurements were made in 14 preterm infants [median (range) gestational age at birth 34 wk (27-37 wk), and at time of study 36 wk (33-40 wk)] who were breathing room air. FRC was measured using a computerized infant pulmonary function system, beginning in random order with either 100% O2 followed by heliox or vice versa. There was no systematic difference between the two methods with regard to lung volume measurements: mean (SD) FRC values, corrected for body weight, were 22.9 (7.1) mL/kg for O2 and 23.4 (7.0) mL/kg for heliox. We did not observe a systematic influence of the type of washing gas used (heliox or oxygen) on FRC in these infants. Our results suggest that the use of heliox instead of pure oxygen may be a suitable and safer alternative for FRC measurements with the nitrogen washout technique in preterm infants who are breathing low concentrations of inspired oxygen and are still at risk of ROP.

Functional Residual Capacity↗
PubMed1995

In vitro assessment of infant pulmonary function equipment.

Commercially available automated pulmonary monitors are used increasingly in neonatal intensive care units. However, detailed information regarding the static and dynamic accuracy of these monitors is rarely available. Collaboration between scientists, clinicians, and manufacturers is essential to establish improved technical standards and protocols for testing of equipment and for the development of more reliable neonatal pulmonary monitors. The aim of this study was to develop a protocol for the in vitro assessment of commercial infant pulmonary function equipment which could be applied within the laboratory to provide rapid feedback to the manufacturer. A recently released neonatal pulmonary monitor, the Bicore CP100 (software version 3.3), was selected for the development of this protocol. The deadspace and resistance of the measuring device were determined. The flow and airway pressure measuring systems were evaluated alone and connected to a tracheal tube for both static accuracy and frequency response. The pressure-volume relationship of the esophageal balloon was determined and its static accuracy and frequency response were assessed. The algorithms for on-line calculations were checked and their correct application confirmed by examination of an ASCII data print out. Finally, the pulmonary monitor was tested during intermittent positive pressure ventilation of a neonatal lung model of known compliance and resistance.

Algorithms↗
PubMed1994

A comparison of respiratory function in Afro-Caribbean and Caucasian infants.

Race is recognized as an important determinant of lung function in children and adults, but limited data exist for infants. Accurate interpretation of lung function tests during the neonatal period may depend on appropriate values for predicting normality. The aim of this study was to compare tidal breathing parameters, Hering-Breuer reflex (HBR) activity, and total respiratory compliance (Crs) in healthy newborn caucasian (white) and Afro-Caribbean (black) infants, to determine whether separate reference values were required for these two ethnic groups. Respiratory function was measured in 33 healthy black infants, 18 of whom were premature, and 33 healthy white infants matched for sex, gestational age, weight, postnatal age, and maternal smoking during pregnancy. There were no significant paired differences between black and white infants with respect to minute ventilation, respiratory frequency, the ratio of time to reach peak expiratory flow to total expiratory time, or HBR activity. Values of Crs were similar in black and white full-term infants (37.5 (SD 9.0) versus 35.0 (6.3) ml.kPa-1, respectively) suggesting that, in the immediate newborn period, separate reference values are not necessary for these parameters. However, Crs was somewhat lower in black than white preterm infants (26.0(5.2) versus 29.5(7.2) ml.kPa-1, this difference reaching statistical significance if results were expressed in relation to body weight (95% confidence interval of within-pair differences -4.0 to -0.02 ml.kPa-1 x kg-1; p < 0.05). We conclude that no separate reference values for tidal breathing, Hering-Breuer reflex activity or total respiratory compliance are required for white and black babies in the immediate newborn period.(ABSTRACT TRUNCATED AT 250 WORDS)

Black People↗
PubMed1994

Effect of continuous negative extrathoracic pressure on respiratory mechanics and timing in infants recovering from neonatal respiratory distress syndrome.

Changes in respiratory mechanics and timing produced by continuous negative extrathoracic pressure (CNEP) of -0.6 kPa were assessed in 18 infants recovering from neonatal respiratory distress syndrome. The median gestational age was 28 wk (range 24-36 wk). All infants were recruited before discharge from neonatal intensive care and were measured at a median postnatal age of 58 d (range 10-127 d) and a median weight of 2.67 kg (range 1.99-3.77 kg). All had been treated for respiratory distress syndrome; 11 were diagnosed as having chronic lung disease. At the time of the study, all infants were stable breathing room air. There was a significant decrease of the respiratory rate in all but one infant from 63.6 +/- 10.0 to 49.3 +/- 9.1 breaths per min (mean +/- SD) during CNEP. This was predominantly due to a marked prolongation of the expiratory time. Passive respiratory mechanics were assessed using airway occlusion techniques. Whereas respiratory system compliance (Crs) did not change in the infants with a normal baseline measurement, there was a significant improvement of Crs in the 11 infants with low Crs values in atmosphere: In the latter, all of whom were very-low-birth-weight infants, Crs assessed by the multiple occlusion technique (mean +/- SD) corrected for body weight increased from 7.9 +/- 1.5 to 9.4 +/- 1.9 mL.kPa-1.kg-1 in CNEP (p = 0.012). There was no consistent change in respiratory system resistance in this population of 18 infants.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1993

Assessment of passive respiratory compliance in healthy preterm infants: a critical evaluation.

The airway occlusion techniques for assessing passive respiratory mechanics have become well established methods in fullterm neonates and older infants. The single breath technique (SBT) is frequently used for assessing lung function in intubated infants on neonatal intensive care units. However, less is known about the reliability of these quick and noninvasive techniques in healthy preterm infants. The aim of this study was to evaluate these methods in healthy unintubated preterm infants to facilitate both establishment of reference values and more meaningful interpretation of lung function assessments in the neonatal unit. Forty-seven studies were attempted in 31 healthy preterm infants (gestational age 29-36 weeks; body weight 1.88 +/- 0.28 kg; mean +/- SD) during the first 2 weeks of life, using both the multiple occlusion technique (MOT) and the SBT. Whereas technically acceptable respiratory system compliance (Crs) data from either the MOT or the SBT were obtained on 37 occasions in 25 infants, satisfactory results from both techniques were achieved only on 22 occasions. In these infants mean +/- SD Crs was 28.1 +/- 5.2 mL kPa-1 when assessed by MOT and 29.1 +/- 6.0 mL kPa-1 when using the SBT. The mean difference between technically satisfactory paired Crs values obtained with MOT and SBT was less than 5% (range, +28 to -18%). By contrast, in infants in whom data were invalidated as a result of expiratory airflow braking, failure to relax or instability of the end-expiratory level, gross discrepancies occurred between the techniques.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗