Bodyplethysmography in healthy children

The relationship of physical conditioning to changes in static lung volumes (hyperinflation) and airway dynamics (bronchoconstriction) as well as to ventilatory gas exchange, heart rate reserve, breathing reserves, and working capacity at a heart rate of 170/min (WC 170) was evaluated in 23 children (16 girls, 7 boys) between 6 and 15 years of age who had perennial asthma. Lung function tests including incremental cycle ergooxymetry were performed before and after a 15-week period of regular physical training (RPT). Lung function data obtained after RPT showed a significant improvement (P less than 0.05) in both hyperinflation and specific airway conductance, whereas oxygen consumption only increased related to lean body mass and heart rate. However, WC 170 and work tolerance during the endurance phase of the exercise test were significantly increased (P less than 0.05 and less than 0.01, respectively). In view of the relationship that has recently been found between exercise tolerance and lung mechanics in adults, the decreased hyperinflation and bronchoconstriction observed in our population after RPT is striking. This finding was presumably a consequence of the effect of RPT on breathing technique and chest wall mechanics. Ventilation of the lungs may improve because of mobilization of the costovertebral articulations, inspiratory muscle relaxation, an optimized force-length relationship of the respiratory muscles, and closer linkage between the diaphragm and intercostal muscles. Therefore, RPT might be an effective addition to standard drug regimens in the management of childhood asthma.

Cardiorespiratory response to physical conditioning in children with bronchial asthma

Ramazanoglu

Kraemer

1985

Long‐term tobramycin aerosol therapy in cystic fibrosis

Steinkamp

Tümmler

Gappa

et al. 1989

134

The long-term efficacy and safety of aminoglycoside aerosol therapy for Pseudomonas aeruginosa colonization/infection in cystic fibrosis has not been fully investigated. In the present study, 14 patients with cystic fibrosis, ages 8-19 years (mean: 13.3 years), received tobramycin aerosol therapy for a mean duration of 20 months. Eighty milligrams of a tobramycin solution were inhaled twice daily after physiotherapy via a jet nebulizer. After 1 year, weight for height increased significantly by 2.9% of the predicted normal, and the Kraemer clinical score increased by 2.1 points (P less than 0.05). The frequency of hospital admissions decreased from 2.0 to 1.3 per patient, respectively, during the years before and after the study onset. The antibody response to P. aeruginosa elastase, exotoxin A, and alkaline phosphatase showed a reduction in serum titers against one or more enzymes in eight patients. The best long-term results after 12-38 months of treatment were obtained in moderately ill children. No evidence of ototoxicity or renal damage was observed. Although intermittent bacterial resistance occurred in five patients after 10-21 months of tobramycin inhalation, this was not associated with clinical deterioration. The study demonstrates the safety and clinical efficacy of long-term tobramycin aerosol therapy. Double-blind studies with larger patient cohorts are required to determine the value of aminoglycoside inhalation as an adjunct to the established therapeutic regimens.

Large difference between Enghoff and Bohr dead space in ventilated infants with hypoxemic respiratory failure

Zuiki

Kume

Matsuura

et al. 2021

Background: Ventilated neonates with hypoxemic respiratory failure (HRF) may show a ventilation-perfusion (V/Q) mismatch.Objective: To evaluate the difference between the Bohr (V d, Bohr ) and Enghoff (V d, Enghoff ) dead spaces in infants by using volumetric capnography based on ventilator graphics and capnograms. Methods: This study enrolled 46 ventilated infants (mean birth weight, 2239 ± 640 g; mean gestational age, 35.5 ± 3.3 weeks). We performed volumetric capnography and calculated V d, Bohr and V d, Enghoff when arterial blood sampling was necessary for treatment. According to the oxygenation index (OI) based on the Montreux definition of neonatal acute respiratory distress syndrome, each measurement was classified into the HRF (OI ≥ 4) or control (OI < 4) group. Then, a regression analysis was performed to evaluate the correlation between the OI and the difference between V d, Enghoff and V d, Bohr .Results: The median V d, Enghoff /tidal volume (V T ) was significantly higher in the HRF group (0.55 [interquartile range, 0.47-0.68]) than in the control group (0.46 [0.37-0.57]). The HRF group showed a larger difference between V d, Enghoff /V T and V d, Bohr /V T than the control group (median, 0.22 [0.15-0.29] vs. 0.10 [0.06-0.14], respectively). Moreover, the regression analysis of the relationship between OI and V d, Enghoff /V T − V d, Bohr /V T showed a positive correlation (r = .60, p < .001). Conclusion:Ventilated neonates with hypoxemic respiratory failure showed a large difference between V d, Enghoff and V d, Bohr , possibly reflecting a low V/Q mismatch and right-to-left shunting.