Archive for the ‘Cystic Fibrosis’
This study has demonstrated that thoracic electrical bioimpedance using the ICG-M401 provides simple, accurate, reliable measurements of Q during exercise in children with CF over a wide range of severity of airflow limitation. Edmunds et al studied ICG in healthy subjects breathing with external resistive loads during exercise and concluded that the method was not influenced by the presumed greater pleural pressure swings and chest wall excursions caused by loaded breathing. Results of the present study support and extend their observations. Chest wall configuration, another factor that could conceivably alter thoracic electrical bioimpedance measurements, likewise did not seem to alter the accuracy or reliability of impedance determination of Q. Although not formally tested in pediatric patients with other diseases characterized by airway obstruction such as asthma or bronchopulmonary dysplasia, one should have no reservations in generalizing findings in the present study to children with these disorders. Read the rest of this entry »
Anthropometric characteristics of the 21 patients (8 male, 13 female) were as follows (mean, [range]): age, 12 (8 to 16) years; height, 146 (120 to 164) cm; weight, 41 (21 to 87) kg; and percent ideal body weight, 105 (83 to 180). Chest length, ie, interelectrode distance, averaged 19 (16 to 24) cm, while thoracic index averaged 0.82 (0.69 to 0.96). Pulmonary function tests showed FVC of 90% (44 to 119%) predicted, FEVX of 77% (33 to 113%) predicted, and forced expiratory flow between 25% and 75% of the FVC of 64% (13 to 120%) predicted. In two patients, Q was successfully measured by RB at one workload only: one boy hyperventilated during the first blood gas measurement; no equilibrium plateau was obtained in one girl at the higher workload despite two attempts. The corresponding impedance Q measurements were therefore excluded from analysis. Read the rest of this entry »
This study received approval from the University of Manitoba Faculty of Medicine Committee for Use of Human Subjects in Research and informed, written consent was obtained from parents and patients alike. The protocol was identical to our study done in healthy children, except that children with CF from the Children’s Hospital of Winnipeg CF Clinic were recruited for the present study. Routine spirometry was performed on a portable spirometer (model AT-6; Schiller AG; Baar, Switzerland) and expressed as percent of predicted. Exercise was performed on an electrically braked cycle ergometer (Excalibur; Quinton Instruments; Seattle) at two work rates: 0.5 and 1.5 W/kg. Subjects pedaled for 4 min before gas exchange measurements commenced, starting with blood gas sampling, followed by mixed expired gas collection for 2 min, and ending with duplicate RB maneuvers. Total duration of work at each load was approximately 8 min. Read the rest of this entry »
Objectives: After validation of impedance cardiography (ICG) in healthy children, this same device was tested in children with cystic fibrosis (CF) to validate its capability of measuring cardiac output (Q) in this population.
Design: Comparative study of ICG vs the indirect Fick (C02) method.
Setting: Tertiary care children’s teaching hospital.
Patients: Twenty-one CF children with mean FEY! of 77±21% predicted. Read the rest of this entry »