Individuality of breathing during volitional moderate hyperventilation.

PURPOSE: The aim of this study is to investigate the individuality of airflow shapes during volitional hyperventilation. METHODS: Ventilation was recorded on 18 healthy subjects following two protocols: (1) spontaneous breathing (SP1) followed by a volitional hyperventilation at each subject's spontaneous (HVSP) breathing rate, (2) spontaneous breathing (SP2) followed by hyperventilation at 20/min (HV20). HVSP and HV20 were performed at the same level of hypocapnia: end tidal CO2 (FETCO2) was maintained at 1% below the spontaneous level. At each breath, the tidal volume (VT), the breath (TTOT), the inspiratory (TI) and expiratory durations, the minute ventilation, VT/TI, TI/TTOT and the airflow shape were quantified by harmonic analysis. Under different conditions of breathing, we test if the airflow profiles of the same individual are more similar than airflow profiles between individuals. RESULTS: Minute ventilation was not significantly different between SP1 (6.71 ± 1.64 l·min(-1)) and SP2 (6.57 ± 1.31 l·min(-1)) nor between HVSP (15.88 ± 4.92 l·min(-1)) and HV20 (15.87 ± 4.16 l·min(-1)). Similar results were obtained for FETCO2 between SP1 (5.06 ± 0.54 %) and SP2 (5.00 ± 0.51%), and HVSP (4.07 ± 0.51%) and HV20 (3.88 ± 0.42%). Only TI/TTOT remained unchanged in all four conditions. Airflow shapes were similar when comparing SP1-SP2, HVSP-HV20, and SP1-HVSP but not similar when comparing SP2-HV20. CONCLUSIONS: These results suggest the existence of an individuality of airflow shape during volitional hyperventilation. We conclude that volitional ventilation alike automatic breathing follows inherent properties of the ventilatory system. Registered by Pascale Calabrese on ClinicalTrials.gov, # NCT01881945.

Respiratory inductance plethysmography is suitable for voluntary hyperventilation test.

The aim of this work was to evaluate the goodness of fit of a signal issued of the respiratory inductance plethysmography (RIP) derivative to the airflow signal during rest, voluntary hyperventilation, and recovery. RIP derivative signal was filtered with an adjusted filter based on each subject airflow signal (pneumotachography). For each subject and for each condition (rest, voluntary hyperventilation, and recovery) comparisons were performed between the airflow signal and the RIP derivative signal filtered with an adjusted filter obtained either on rest signal or on the studied part of the signals (voluntary hyperventilation or recovery). Results show that the goodness of fit was : (1) higher than 90% at almost all comparisons (122 on 132), (2) not improved by applying an adjusted filter obtained on the studied part of the signals. These results suggest that RIP could be used for studying breathing during voluntary hyperventilation and recovery using adjusted filters obtained from comparison to airflow signal at rest.

Development of family medicine education in Moldova with Carelift International.

BACKGROUND: As in other former Soviet republics, Moldova's health system has been dependent upon multispecialty and hospital care. The government has undertaken a planning process to develop a primary care-based system utilizing family physicians. Carelift International and Moldova State Medical and Pharmaceutical University joined together to design an educational program to help create a family medicine specialty in the country. METHODS: Introductory concepts were incorporated into a workshop co-sponsored by the World Health Organization, Carelift International, UNICEF and Moldova Ministry of Health. Faculty teams participated in Carelift's 8-week US program, comprising a range of topics in family medicine: educational development at all levels, public health applications, health care organization, insurance, financing, and technology. Training also included 1 week in Finland, a fellowship in Lithuania, an in-country workshop on rural health, and a supplemental 5-week US immersion program. OUTCOMES: A Department of Family Medicine was established, and a residency program instituted. It has already been strengthened with a 2-week introduction to the specialty, and rotations in family practice centers. Continued improvements and updates are planned. Urban and rural model family practice centers serve concurrent purposes of teaching, demonstrating and health care. Carelift shipped equipment for the principal center and a department library, and is equipping a teaching family practice center near the university. The Society of Family Physicians of Moldova was founded. The introduction of family medicine as a discipline into the health system of Moldova could be a valuable model for other former Soviet republics.