Search PubMed⌕ Search

Biomedical subjects

J S Haight

Publications and source records attributed to J S Haight.

At least 37 records · Page 2Linked to original sources
PubMed1993

Laryngeal resistance to respiratory airflow in humans.

Although vocal cord adduction has been observed during expiration, measurements of absolute values of resistance changes in man have not been reported in the literature. The authors measured resistance to translaryngeal respiratory airflow in inspiratory and expiratory phases of the respiratory cycle of four healthy, awake men during nasal breathing. It was found that, during quiet breathing through a decongested nose, translaryngeal resistance was 1.245 cm H2O/L per second in expiration and 0.354 cm H2O/L per second in inspiration (.005 < P < or = .01), for a percentage of approximately 25% and 50% of extrathoracic expiratory and inspiratory resistances, respectively. Voluntary hyperventilation decreased expiratory resistance, and a partial nasal obstruction abolished the statistical difference between translaryngeal inspiratory and expiratory resistance. These results are in agreement with previous observations of vocal cord movement and are consistent with an expiratory braking effect on airflow.

Adult↗
PubMed1993

Snoring and nasal resistance during sleep.

Although it is widely accepted that nasal obstruction leads to snoring and sleep apnea, the relationship between these variables is not clear, mainly because of the lack of studies in which nasal resistance (Rna) and snoring were measured concurrently. The authors studied eight nonapneic snoring men with healthy noses by nocturnal polysomnography that included quantitative assessment of snoring and concomitant nasal resistance. In six of these eight patients nasal resistance increased during sleep, but there was no significant change for the group as a whole between wakefulness (0.209 +/- 0.224 Pa/cm3 per second) and sleep (0.292 +/- 0.203 Pa/cm3 per second). Linear regression analysis showed no significant correlation between sleeping nasal resistance and snoring index (partial R2 = .44, P = .071). We used each subject as his own control and compared the snoring profile at a time during sleep when nasal resistance was at its highest (0.550 +/- 0.375 Pa/cm3 per second) and lowest (0.146 +/- 0.090 Pa/cm3 per second) levels. Despite the significant (P < .01) differences in nasal resistance, they were not reflected in the number of snores or their sound intensity. It is concluded that nasal obstruction during sleep is not correlated significantly to frequency or intensity of snoring during exclusively nasal breathing.

Adult↗
PubMed1991

Site of airway obstruction in patients with obstructive sleep apnea before and after uvulopalatopharyngoplasty.

This study describes a simple method, based on a movable catheter technique, for use during routine polysomnography to identify the site of obstruction, and this has been applied to 51 patients with suspected sleep apnea. The obstruction was found to be retropalatal in 30, retrolingual in 7, and could not be determined in 14 patients (12 had no sleep apnea, 1 did not sleep, and 1 had central sleep apnea). Twelve of these patients had uvulopalatopharyngoplasty with preoperative and postoperative polysomnograms to determine the site of obstruction. The preoperative obstruction was retropalatal in nine and retrolingual in three. Postoperatively, four patients (one with retrolingual obstruction and three with retropalatal obstruction) no longer had sleep apnea. In the remaining eight patients, the site of obstruction was unchanged from the preoperative one. Several conclusions result: 1. the movable catheter technique offers a simple way to determine the site of obstruction in patients with significant obstructive sleep apnea, 2. most such patients obstruct in the retropalatal region, and 3. preoperative localization of the site of obstruction to the retropalatal region does not seem to improve the surgical outcome of uvulopalatopharyngoplasty.

Adult↗
PubMed1991

Resolution of obstructive sleep apnea following facial surgery.

Compared to uvulopalatopharyngoplasty (UPPP), maxillo-facial surgery is rarely performed in Canada for treatment of obstructive sleep apnea. However, in patients with retrolingual obstruction, UPPP cannot be expected to result in good surgical outcome. We describe a patient with retrognathia causing airway obstruction at the base of the tongue, in whom sagittal mandibular osteotomy with hyoid bone advancement resulted in resolution of snoring and sleep apnea.

Adult↗
PubMed1991

Snoring, apnea and nasal resistance in men and women.

To examine if gender and airway resistance (nasal and pulmonary) influence the loudness and intensity of snoring, we prospectively studied 370 unselected patients referred to our sleep clinic because of heavy snoring and a possibility of sleep apnea. All patients had full nocturnal polysomnography, including measurements of snoring using a calibrated microphone-sound meter system, and determination of pulmonary (Raw) and nasal resistance (Rna). Snoring was quantified by reporting the number of snores per hour of sleep (snoring index--SI) and the maximum nocturnal sound intensity (dBmax). The patient population comprised 77 females and 293 males, ranging in age from 12 to 80 years. Based on the apnea/hypopnea index (AHI) we separated all patients into the apneic and non-apneic groups. There were 201 non-apneic snorers (AHI less than or equal to 10) and 160 apneic snorers (AHI greater than 10). There was no significant difference in snoring frequency, maximum nocturnal sound intensity, nasal and pulmonary resistance between men and women or between apneic and non-apneic snorers. Stepwise, forward, multiple linear regression analysis showed that body mass index and nasal resistance correlate significantly with the snoring index (R2 = 0.29, p less than 0.005), while age and body mass index correlate only weakly, but significantly, with the maximum nocturnal sound intensity. We conclude that (1) men snore similarly to women, and (2) obesity and nasal resistance are important determinants of the frequency of snoring. It follows that measures taken to reduce weight and decrease nasal resistance may be of benefit in reducing snoring.

Adolescent↗
PubMed1989

Is the nasal cycle an artifact? The role of asymmetrical postures.

Both the nasal cycle and postural asymmetries between the lateral halves of the body will cause the patent cavity of the nasal airway to change sides. Therefore, the cycle might result from adjustments of posture during prolonged periods of nasal resistance measurements. Posterior rhinometric measurements of unilateral nasal resistance were made three times for 5 to 7 hours on a patient in whom 11 periods of lateral recumbency had not induced nasal resistance changes. A nasal cycle was observed. It is concluded that the cycle is not the product of asymmetrical body pressures.

Adult↗
PubMed1989

Nasal cryosurgery and cautery: should the septum be treated and is a diagnosis relevant?

Posterior rhinometric measurements of nasal resistance were conducted on two groups of patients with perennial rhinitis: those whose symptom of nasal stuffiness responded to a topical steroid spray and those in whom it did not. The anterior ends of the inferior turbinates in 48 patients were treated with either cryosurgery or cautery, and in half of the subjects the erectile tissue of the septum was also thermally ablated. Measurements were made before and 10-16 weeks after therapy. It is concluded from statistical comparison that there is no benefit to treating the septum, and that cryosurgery is more effective in those whose symptoms respond to topical steroids, while cautery works better in those who do not. Histology showed no change in the capacitance vessels (sinusoids) after either modality, and xylometazoline caused a marked decrease in nasal resistance, suggesting that vascular smooth muscle function was intact. Irrespective of the change in airway resistance, most subjects felt that there had been an improvement. The mechanism is discussed.

Adult↗
PubMed1986

Unilateral nasal resistance and asymmetrical body pressure.

Lateral recumbency causes ipsilateral nasal congestion and contralateral decongestion. Nasal resistances were measured before, during and after the application of pressure either regionally or by lateral recumbency. In some experiments an attempt was made to block the response by local anesthetic injection, splinting the nasal vestibules, or topical decongestants. In others an electric blanket was employed as a stimulus instead of pressure. It was concluded that the nasal resistance changes during lateral recumbency are due to pressure receptors in the pelvic and pectoral girdles, and thorax. These adapt slowly. They are probably situated in the intercostal spaces, parietal pleura, or sterno-costal joints. Their centripetal fibers probably travel in the intercostal nerves, and their efferents in the cervical sympathetic outflow to the nasal erectile tissue. Lateral recumbency of 12 minutes' duration induces changes in nasal resistance which persist after the pressure asymmetry has been terminated. This may be due to temporal summation.

Adult↗
PubMed1986

Reversible obstructive sleep apnea caused by occupational exposure to guar gum dust.

This report describes a case of reversible obstructive sleep apnea caused by occupational exposure to an inhaled allergen, guar gum powder. The patient, a pet food plant employee, also experienced severe cough, rhinitis, and conjunctivitis. Skin tests confirmed the specific guar allergy. Pharyngeal cross-sectional area was smaller than normal. Pulmonary function studies, histamine challenge tests, nasal air-flow resistance measurements, and nocturnal polysomnography were performed on 3 separate occasions: while the patient was working at his usual occupation, at the end of a 3-wk holiday, and after a guar dust challenge in an inhalation chamber. Pulmonary function and histamine challenge tests were consistently normal. At the time of the initial tests, nasal resistance was elevated, and nocturnal polysomnography revealed obstructive sleep apnea. After absence from work, obstructive sleep apnea resolved, and the nasal resistance returned to normal. After challenge with guar gum dust, the patient developed increased resistance to nasal air flow, and obstructive sleep apnea reappeared. This case demonstrates that allergy can cause reversible obstructive sleep apnea and that occupational exposure should be considered in the assessment of patients with this disease.

Adult↗
PubMed1985

Dynamic components of nasal resistance.

This investigation was undertaken to demonstrate the contributions of dynamic vestibular and mucosal components to nasal air-flow resistance in healthy human adults. The studies were made by video recording of alar movement, electromyography of alar muscle activity, and by computer-assisted plethysmographic measurement of nasal air-flow resistance. Inspiratory approximation of the alae toward the septum from their expiratory position averaged only 0.6 mm at the high nasal ventilation of 35 L/min; it was less at lower ventilation and absent during voluntary mouth breathing. Inspiratory electromyographic activity also was directly related to the extent of nasal ventilation and was absent during voluntary mouth breathing. The activity was consistent with phasic muscular restraint of vestibular compliance with inspiratory transnasal pressures. Physiologic nasal air-flow resistance changes associated with posture, the nasal cycle, exercise, and hyperventilation persisted despite immobilization of the alae by splinting the vestibule widely open. These changes were abolished by topical decongestant, even in the unsplinted nose, and are therefore vascular.

Adult↗
PubMed1985

The choana and nasal obstruction.

A subject with a septal perforation was studied rhinometrically to confirm that the congested choana did not limit airflow when the anterior nose was decongested. It did not. This suggests that in an undefined proportion of patients with swollen diseased mucosa, surgery to the anterior nose may be sufficient to relieve nasal obstruction.

Adrenergic alpha-Antagonists↗
PubMed1985

Nasal mucosal anaesthesia and airflow resistance.

The effect of topical lidocaine solution on nasal airflow resistance was examined in five adult subjects with normal noses, seated and recumbent. The increasing use of upper airway anaesthesia in the investigation of upper airway function and the lack of published information concerning its effect on nasal airflow resistance led to this investigation. Nasal airflow resistance did not significantly change during 30 minutes observation following topical application of 4% lidocaine solution.

Adult↗
PubMed1984

Posture and nasal patency.

Effects of recumbency on nasal patency were determined in adult subjects by a sensitive computer-assisted posterior rhinometric technique. A modified body plethysmograph was employed to measure air flow and to avoid the disadvantages of facial masking and nasal intubation. In healthy subjects, assumption of recumbency decreases total nasal patency minimally. Lateral recumbency decreases it markedly in the ipsilateral nasal cavity, in which resistance to breathing often exceeds 10 cm H2O (1.0 kPa)/L/s. A concomitant increase in patency, which takes place contralaterally (resistance is frequently reduced to less than 3 cm H2O (0.3 kPa)/L/s), diminishes change in total nasal patency. Ipsilateral decrease and reciprocal contralateral increase in patency are induced also by unilateral pressures to trunk and limbs in dorsally recumbent subjects. This posture minimizes hydrostatic differences between sides. The results indicate that reciprocal nasal vascular responses to lateral recumbent postures are caused by pressure-induced reflexes, and these changes take place independent of hydrostatic differences. Effects of recumbency on the patency of abnormal noses and their relevance to breathing disorders of sleep are discussed.

Adult↗
PubMed1984

Mechanisms of nasal obstruction in sleep.

Pathophysiological aspects of the nasal and pharyngeal airways are discussed with particular reference to breathing disorders in sleep. Hypotonus of dilator muscles in sleep permits the pharynx to comply with inspiratory pressures. If airflow resistances are increased by nasal disease, complete inspiratory obstructive closure of the pharynx and apnea can result from nasal breathing in sleeping subjects. Recumbency increases resistive swelling of inflamed nasal mucosa. Furthermore in patients with normal mucosa and unilateral nasal obstruction, contralateral recumbency induces contralateral obstruction which increases resistance to nasal breathing; and in either dorsal or lateral recumbency the congestive phase of the spontaneous nasal cycle acts in a similar way. Examples of breathing disorders in sleep and impaired quality of sleep in patients with obstructive mucosal disease and both bilateral and unilateral structural abnormalities are cited.

Airway Resistance↗
PubMed1984

Ventilation during laryngoscopy in chronic obstructive lung disease.

Many patients requiring direct examination of the upper airway and gastrointestinal tract under general anesthesia have chronic obstructive lung disease, yet virtually no work has been done to assess the adequacy of their ventilation during laryngoscopy and in the early postoperative period. This study demonstrates that, using the Carden tube, their blood gases are well maintained even when areas outside the endolarynx, such as the upper esophagus, are examined. The Carden tube is shown to be easy to insert and remove as well as permitting a superior view of the larynx. Also, this study pinpoints the period of maximum danger of respiratory failure as occurring postoperatively in the recovery room. This should be independent of the method of ventilation employed at surgery and indicates the need for cocainization of the vocal cords before extubation, as well as careful, early postoperative monitoring. The problems of ventilation during direct examination of the upper airway and gastrointestinal tract are discussed and alternative methods evaluated.

Adult↗
PubMed1983

Snoring in adults: some epidemiologic aspects.

Although snoring is a common problem it has received little attention in the medical literature. Therefore, a study was undertaken to determine the prevalence and epidemiologic aspects of snoring. The results showed that it is much more common than previously thought--86% of the married men and 57% of the married women were reported to snore. Overall, snoring was found to be more frequent in adult men than women, and its prevalence in adults was not related to age. It was found that 15% of the husbands and 52% of the wives were bothered by their spouse's snoring. Physicians must be made more aware of this problem and its potential effects on patients.

Adult↗
PubMed1983

The site and function of the nasal valve.

Previous observers have suggested that the main site of respiratory airflow resistance is localized to the vestibular region of the nose. This resistive segment of the airway was investigated using a "head-out" body plethysmograph in subjects with anatomically normal noses (a) untreated, (b) congested and (c) decongested. In all three conditions, 2/3 of the total nasal airflow resistance was found within the bony cavum in the vicinity of the pyriform aperture and about 1/3 in the cartilaginous vestibule. As might be expected, caval resistance changed proportionately with the degree of mucosal congestion; but, more surprisingly, vestibular resistance changed similarly. This was due in part to the observed forward expansion of the anterior ends of the inferior turbinates with congestion. EMG recordings in subjects breathing through both nostrils demonstrated a gradation of inspiratory alar dilator muscle activity with increased minute ventilation and with mucosal congestion, and there was no evidence of inspiratory alar collapse. But with elevated ventilation through one nostril only, or when the alar muscles were paralyzed by lidocaine block of the VIIth nerve, alar collapse occurred. These findings are of importance in the management of the congested but anatomically normal nose and in surgery of the nasal tip.

Adult↗