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Biomedical subjects

D O Rodenstein

Publications and source records attributed to D O Rodenstein.

At least 73 records · Page 4Linked to original sources
PubMed1991

Pattern of snoring in obstructive sleep apnea patients and in heavy snorers.

We measured respiratory mechanical characteristics during sleep in five heavy, nonapneic snorers (HS) and in five obstructive sleep apnea (OSA) patients. In two HS and in two OSA patients we obtained lateral pharyngeal cineradiographic images during sleep while snoring. Flow limitation preceded all snores in both HS and OSA. Pattern of snoring, hysteresis and temporal relationship between supraglottic pressure (Psg) and flow rate were different in HS and OSA. Maximal flow during snoring was less (p less than 0.05) in OSA (0.18 +/- 0.07 liter/second) than in HS (0.36 +/- 0.06 liter/second). Linear supraglottic resistance during inspiratory snoring was higher, though not significantly, in OSA patients (7.11 +/- 3.01 cm H2O/liter/second) than in HS (4.80 +/- 2.83 cm H2O/liter/second). We conclude that: 1) Snoring is characterized by high frequency oscillations of the soft palate, pharyngeal walls, epiglottis and tongue. 2) Flow limitation appears to be a sine qua non for snoring during sleep. 3) The pattern of snoring is different in OSA and HS. 4) Pharyngeal size during snoring is probably larger in HS than in OSA patients.

Adult↗
PubMed1991

Spontaneous favorable outcome of tracheal laceration.

We present the case of a 57-year-old woman with a huge tracheal laceration after intubation. With simple supportive therapy, the laceration healed in ten days, and the patient made an uneventful recovery. At the three-month follow-up, no sequelae were observed.

Female↗
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

Cure of sleep apnea syndrome after long-term nasal continuous positive airway pressure therapy and weight loss.

Two male patients [aged 53 and 54 years; body mass index (BMI) of 36.8 and 34.4 kg/m2] presented with severely symptomatic sleep apnea syndrome. Polysomnographic recording showed sleep fragmentation, diminution of stages III and IV and continuous sleep-related disordered breathing with mixed and obstructive apneas and hypopneas, and snoring. Apnea index (number of apneas per sleep-hour) was 73 and 30, respectively. These abnormalities were reversed by nasal continuous positive airway pressure (nCPAP). Home treatment with nCPAP associated with hypocaloric diet was started. Six months later, all symptoms had disappeared and BMI was 29 and 29.2 kg/m2, respectively. Polygraphic recordings without nCPAP showed regular breathing in all sleep stages, which were stable and normally abundant. Therapy has been discontinued and clinical and polygraphic data have remained normal for up to 6 and 11 months, respectively.

Arousal↗
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↗
PubMed1989

Failure of tonsil and nose surgery in adults with long-standing severe sleep apnea syndrome.

Seven adult patients with a severe form of sleep apnea syndrome (mean apnea index, 47) underwent surgery for significant structural abnormalities at nose and/or throat level (septal deviation, turbinal hypertrophy, enlarged tonsils, long uvula, pharyngeal tumor). Although a subjective benefit was claimed by most patients, the polygraphic data showed no improvement or only a modest improvement in breathing pattern, oxyhemoglobin saturation, or general sleep architecture except in one patient. In this patient the evolution of the syndrome was recent (3 years) and surgical management of a parapharyngeal tumor resulted in a cure. We conclude that in adults with sleep apnea syndrome of long-standing, surgical correction of nasal or pharyngeal abnormalities should not be expected to normalize sleep and breathing. This contrasts with the known benefits achieved by the same type of surgery in children. Surgery might nevertheless be necessary in some adults to permit the application of other therapeutic means (ie, nasal continuous positive airway pressure).

Adult↗
PubMed1988

Ventilatory and diaphragmatic EMG changes during negative-pressure ventilation in healthy subjects.

To evaluate the response of normal subjects to assisted ventilation, we studied 6 naive healthy subjects before and during negative-pressure ventilation (NPV) with "low" (-10 cmH2O) and "high" (-30 cmH2O) pressures in an Emerson tank respirator. Ventilation was measured with an inductive plethysmograph (Respitrace), and diaphragmatic electromyogram (DEMG) was studied with a bipolar esophageal electrode. During NPV a 1:1 phase lock was observed between subjects and iron lung frequency in all subjects. Tidal volume increased in most subjects, more with high than with low pressures (P less than 0.05), whereas DEMG increased, decreased, or showed no change. Postinspiratory inspiratory diaphragmatic activity (PIIA) significantly increased during high-pressure NPV and was accompanied by an increase in tonic DEMG in one-half of the subjects. Voluntary relaxation resulted in a decrease in DEMG and PIIA. We suggest that cortical activity can explain persistency of active breathing during negative-pressure ventilation.

Adult↗
PubMed1988

Ventilatory and diaphragmatic EMG responses to negative-pressure ventilation in airflow obstruction.

To assess the responses of patients with chronic obstructive lung disease (COLD) to negative-pressure ventilation (NPV), we studied eight naive patients with moderate to severe COLD before (control) and during NPV with "low" (-10-cmH2O) and "high" (-30-cmH2O) pressure swings in a Drinker tank respirator. Tidal volume (VT) and minute ventilation (VE) were recorded from a Respitrace and diaphragmatic electromyogram (DEMG) from a bipolar esophageal electrode. During short, 5-min runs of "low" and "high" NPV, VT did not change and VE increased in a borderline significant way at -30-cmH2O NPV. Peak integrated DEMG amplitude did not change with respect to control during short runs of NPV. However, when NPV was maintained for 20-60 min, a significant (though small, 20%) decrease in peak DEMG amplitude was observed with respect to control. By contrast, in a ninth patient habituated to NPV, the decrease in peak DEMG amplitude during a 5-min run of NPV was 60%. Significant increases in arterial PO2 (at -10- and -30-cmH2O NPV) and decreases in arterial PCO2 (at -30-cmH2O NPV) were found during NPV for the whole group of patients. One-to-one phase locking between the respirator and patients was the most common pattern of entrainment observed. However, 1:1 phase locking did not preclude the presence of dissociation between the two pacemakers. We conclude that short runs of NPV in naive patients do not result in changes in DEMG, as opposed to immediate and nearly complete cessation of inspiratory activity in trained patients.

Diaphragm↗
PubMed1988

[The role of the soft palate in respiration].

The soft palate is a muscular fold suspended from the posterior border of the bony palate and extending downwards and backwards into the oropharynx. Usually, the soft palate and tongue are in tight apposition, closing the oropharyngeal isthmus; the soft palate can however rise and touch the posterior pharyngeal wall, closing the nasopharynx: thus the soft palate regulates the flow of air through nose and/or mouth. During oronasal breathing (as during exercise, speech or smoking) the impedance of naso and oropharynx respectively is determined by the position of the soft palate. Hence partitioning of the airflow through nose and mouth will depend on the latter. This is true in both adults and babies. Babies are not obligatory nasal breathers (as was previously thought). This applies as well as to near miss for sudden infant death syndrome babies. The soft palate is also involved in the genesis of snoring and the sleep apnea syndrome.

Adult↗
PubMed1987

Ambulatory evaluation of sleep disturbance and therapeutic effects in sleep apnea syndrome by wrist activity monitoring.

A new wrist actometer was used to obtain ambulatory activity-rest recordings in 18 patients with sleep apnea syndrome (SAS) and in 22 control subjects. A movement index (MI) and a fragmentation index (FI) during sleep time were computed, giving an estimate of the stability of sleep. In control subjects, we observed a clear differentiation between night and day activity levels. The distribution of MI and FI was very narrow, with a mean +/- SD of 13.9 +/- 5.4 and 16.1 +/- 5.8%. No correlation of MI and FI with body mass index, even in heavily obese subjects, was found; MI and FI decrease significantly with age. A diagnosis of SAS was made by standard all-night polysomnography. Patients with SAS had a significantly higher MI and FI than did control subjects (p less than 0.001). With respect to polysomnographic diagnosis of SAS, the sensitivity of activity recordings was 89%, whereas the specificity was 95%. Five patients were studied after treatment, and decreases in MI and FI at home were in good agreement with the improvement in their sleep as assessed clinically and by polysomnography. We conclude that this technique is useful for an objective measurement of sleep restlessness and fragmentation, and for a simple evaluation of therapeutic effects under real life conditions in SAS.

Adult↗
PubMed1987

"Sensitive tests" are poor predictors of the decline in forced expiratory volume in one second in middle-aged smokers.

In 1978, we studied 3 groups of steelworkers 45 to 55 yr of age who were all smokers: "obstructive" smokers (OS) with a FEV1/VC less than 66.6% (59.8% in average) (n = 37), smokers with "small airways disease" (SAD) and an abnormal closing capacity and/or slope of phase III (delta N2) but normal FEV1/VC (n = 32), and "resistant" smokers (RS) with normal functional indices (n = 36). Smokers with SAD had a lower (p less than 0.05) FEV1/VC (71.7%) than did RS (74.9%). We studied again 6 yr later about 85% of survivors in each group. Analysis of variance showed that FEV1 decreased significantly (p less than 0.001) only in OS (from 2.67 to 2.46 L). In RS and smokers with SAD, FEV1 declined from 3.34 to 3.26 L and from 2.95 to 2.85 L, respectively (p greater than 0.05). In all 3 groups, delta N2 increased (p less than 0.001) from 0.77 to 1.30% N2/L in RS, 1.41 to 2.43% N2/L in smokers with SAD, and 2.22 to 4.20% N2/L in OS. A multivariate analysis showed that the initial N2 explained about 30% (p less than 0.001) of the decline in FEV1 in OS, but only 10% (p less than 0.001) in the 3 groups together. In fact, the link between delta N2 and fall in FEV1 was restricted to OS. Closing volume and maximal expiratory flow rates were not related to decline in FEV1. The link between uneveness of ventilation and subsequent loss of FEV1 is of physiopathologic interest.(ABSTRACT TRUNCATED AT 250 WORDS)

Forced Expiratory Volume↗
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↗
PubMed1985

Influence of the respiratory route on the resting breathing pattern in humans.

It has been shown that the pattern of breathing is modified when breathing through a mouthpiece (MP) with a noseclip (NC), although the reasons for this are not clear. We studied 14 healthy naïve subjects during unrestrained breathing, while connected to a spirometer without NC, and while connected to a spirometer with NC. Breathing pattern, studied with an inductive plethysmograph (Respitrace), was recorded during 4 min in each case, once a steady state was attained. During unrestrained breathing, all subjects breathed exclusively through the nose. During spirometric testing without NC, 9 of 14 subjects still breathed through the nose only (since the oropharynx is closed by the soft palate and the tongue, and flow proceeds through the nose). Tidal volume (VT), frequency (f), minute ventilation (VE), inspiratory time, mean inspiratory flow, and duty cycle (Tl/Ttot) were not different during the first 2 procedures (p greater than 0.1 by analysis of variance). By contrast, during spirometric testing with NC, mean VT increased from 530 (during unrestrained breathing) to 700 ml (p less than 0.02), whereas f decreased from 14.9 to 13.6 breaths X min-1 (p greater than 0.05), VE did not change, and Tl/Tot increased from 37 to 41% (p less than 0.05). These data suggest that the change in the pattern of breathing depends on the breathing route. To further confirm this, we asked 8 separate subjects to simply breathe through either the nose or the mouth (half of them starting with mouth breathing, half with nose breathing) while respiration was monitored with the Respitrace without any connection to the airways.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗