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Biomedical subjects

D C Stanescu

Publications and source records attributed to D C Stanescu.

At least 19 recordsLinked to original sources
PubMed1990

Pharyngeal shape and dimensions in healthy subjects, snorers, and patients with obstructive sleep apnoea.

To characterise the relation between pharyngeal anatomy and sleep related disordered breathing, 17 men with complaints of snoring were studied by all night polysomnography. Ten of them had obstructive sleep apnoea (mean (SD) apnoea-hypopnoea index 56.3 (41.7), age 52 (10) years, body mass index 31.4 (5.3) kg/m2); whereas seven were simple snorers (apnoea-hypopnoea index 6.7 (4.6), age 40 (17) years, body mass index 25.9 (4.3) kg/m2). The pharynx was studied by magnetic resonance imaging in all patients and in a group of eight healthy subjects (age 27 (6) years, body mass index 21.8 (2.2) kg/m2, both significantly lower than in the patients; p less than 0.05). On the midsagittal section and six transverse sections equally spaced between the nasopharynx and the hypopharynx several anatomical measurements were performed. Results showed that there was no difference between groups in most magnetic resonance imaging measurements, but that on transverse sections the pharyngeal cross section had an elliptic shape with the long axis oriented in the coronal plane in normal subjects, whereas in apnoeic and snoring patients the pharynx was circular or had an elliptic shape but with the long axis oriented in the sagittal plane. It is suggested that the change in pharyngeal cross sectional shape, secondary to a reduction in pharyngeal transverse diameter, may be related to the risk of developing sleep related disordered breathing.

Adult↗
PubMed1989

Adaptation to intermittent positive pressure ventilation applied through the nose during day and night.

A 49 yr old poliomyelitic patient had been under cuirass-type nocturnal negative pressure ventilation for more than 20 yrs. He had a severe restrictive ventilatory impairment, and normal awake blood gases at rest and during light exercise. He was offered a trial of intermittent positive pressure ventilation applied through the nose (nIPPV). Two daytime studies and one night study were carried out under nIPPV, and one night study was performed under negative pressure ventilation. Tidal volume, respiratory frequency (Respitrace), blood gases and electromyogram (EMG) of the diaphragm (DEMG, oesophageal electrode) and/or sternocleidomastoid (ScEMG, surface electrodes) were measured. During daytime studies under nIPPV, the DEMG (and/or the ScEMG) did not decrease by more than 25% (p less than 0.005). However, when the patient was encouraged to relax, the DEMG decreased by 62% (p less than 0.001). Tidal volume and ventilation significantly increased during daytime nIPPV (p less than 0.025), whereas blood gases were kept at physiological levels. At night, the ScEMG was present and prominent until sleep onset. Thereafter it disappeared and remained silent, including periods of wakefulness during sleep time, until final awakening in the morning. This was true for both negative pressure ventilation and nIPPV. Snoring was present throughout sleep under negative pressure ventilation but not under nIPPV. We conclude that the behavioural response of the subject may determine the electrical activity of respiratory muscles during assisted ventilation.

Adaptation, Physiological↗
PubMed1986

[Aerodynamic studies of the upper respiratory tract].

The usefulness of flow-volume curves for the assessment of upper airway function is emphasized. The different behaviour of intra- and extra-thoracic airways, submitted to different transmural pressures, results in the reduction of maximum expiratory flows in cases of variable intrathoracic airways stenosis, whereas in the presence of an extrathoracic stenosis, the inspiratory maximum flows are mainly affected. Sleep apnea syndrome and "asthma-like" syndromes with a glottic origin are further examples of the potentials of flow-volume loops in the assessment of upper airway function.

Asthma↗
PubMedDate not supplied

Action of isoprenaline on the mechanical properties of lungs and airways in healthy people and patients with obstructive lung diseases.

Lung volumes, maximal expiratory flows, pulmonary resistance and static recoil pressure-volume curves were measured before and after inhalation of isoprenaline in four groups of subjects: heqlthy patients with mild and severe chronic bronchitis and asthmatics. The observed changes were qualitatively similar in the four groups. Whereas total lung capacity and dynamic compliance were not influenced, there was an increase in vital capacity (not in healthy subjects and mild bronchitics), in FEV1, in maximal expiratory flows and a decrease in pulmonary resistance. The static recoil pressure-volume relationship was shifted to the left over its ascending part. The effect of isoprenaline tended to be larger in patients. Among the latter, the increase of vital capacity was especially pronounced in the severe bronchitics, whereas the maximal flows increased most in asthmatics. We suggest that the influence of isoprenaline on maximal flows results from a bronchodilation, associated with an increased collapsibility of the central intrathoracic airways, whereas the influence of VC might reflect a delayed onset of small airway closure.

Adult↗