Document Detail

Ventilatory responses to passive leg motion in children with congenital central hypoventilation syndrome.
MedLine Citation:
PMID:  8564130     Owner:  NLM     Status:  MEDLINE    
During exercise, children with congenital central hypoventilation syndrome (CCHS) demonstrate coupling of VE to exercise load, despite the absence of a VE response to changes in FICO2. To assess the effect of movement on VE, we studied six CCHS patients and six matched controls during passive motion in a motor-driven ergocycle at pedaling frequencies (PF) of 6 to 60 rpm. VE, VO2, VCO2, VT, heart rate, respiratory rate, SPO2, and PETCO2 were measured. During steady-state conditions, VE was constant at PF of 0 to 30 rpm, but increased at PF > or = 40 rpm in both controls and CCHS patients (p < 0.005). The increase in respiratory rate in CCHS patients was greater than in controls (p < 0.05) whereas VT increased similarly in both groups. At 60 rpm, VO2 increased in both groups, but VE/VO2 and VE/VCO2 increased in the CCHS patients and remained constant in the controls (P < 0.03; p < 0.04). From PF of 0 to 60, PETCO2 decreased from 47 +/- 7 to 41 +/- 6 mm Hg in the CCHS patients (p < 0.001) but remained unchanged in the controls (38 +/- 3 mm Hg; p = NS). An analysis of on-transient responses at 60 rpm revealed that VE increased immediately with the first breath after onset of motion in both groups, and that comparable differences in ventilatory patterns persisted in the two groups. We conclude that passive leg motion at PF > or = 40 increases VE in both CCHS patients and controls. In controls, VE was tightly coupled to VO2 and VCO2. However, in CCHS patients, passive leg motion elicited normalization of PETCO2.
D Gozal; C L Marcus; S L Ward; T G Keens
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  American journal of respiratory and critical care medicine     Volume:  153     ISSN:  1073-449X     ISO Abbreviation:  Am. J. Respir. Crit. Care Med.     Publication Date:  1996 Feb 
Date Detail:
Created Date:  1996-03-06     Completed Date:  1996-03-06     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  9421642     Medline TA:  Am J Respir Crit Care Med     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  761-8     Citation Subset:  AIM; IM    
Division of Neonatology and Pediatric Pulmonology, Childrens Hospital Los Angeles, California, USA.
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MeSH Terms
Pulmonary Gas Exchange
Respiratory Mechanics
Sleep Apnea Syndromes / congenital,  physiopathology*
Grant Support

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