Exercise-induced laryngospasm of emotional origin.
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Asthma, Exercise-Induced↗
Biomedical subjects
D Rodenstein
Publications and source records attributed to D Rodenstein.
Hypopharyngeal and neck cross-sectional changes monitored by inductive plethysmography.
We present a method to assess cross-sectional area (CSA) changes of the extrathoracic airways (EA) by using an inductive plethysmograph (IP) band placed around the upper part of the neck. Measurements of mouth pressure (Pm) (or flow rate, V) and neck CSA changes during respiratory efforts against a high (or infinite) resistance have shown a highly significant relationship between Pm changes (or V changes, respectively), reflecting CSA changes of the EA and CSA changes of the neck. Simultaneous measurements of CSA of the neck (by IP) and of EA (by computerized tomography) during sustained inspiratory and expiratory efforts against a closed airway showed a high correlation between changes in the former and latter structures. Changes in CSA of the neck were larger with positive than negative transmural pressures, in keeping with the known larger compliance of this airway during expiration. We found this method helpful to assess the behavior of the EA during obstructive apnea episodes, hypopneas, and snoring.
Adult↗
[Plasma cell granuloma of the lung. Apropos of a case and review of the literature].
A case of plasma cell granuloma of the lung is presented, and the clinical, radiological, histological, diagnostic and therapeutic data obtained from 97 published cases are reviewed. Since the disease is usually peripheral, the diagnosis rests on surgical biopsy and histological examination. In the case presented here, it was established on intrabronchial biopsy obtained by fibroscopy.
Adult↗
Effects of two inotropic drugs, dopamine and dobutamine, on pulmonary gas exchange in artificially ventilated patients.
The inotropic agents, dopamine (DP) and dobutamine (DB), both decrease PaO2, probably by a redistribution of the VA/Q ratio. The aim of this study was to assess the effect of both drugs on the VA/Q ratio, using the multiple inert gas elimination method. Ten artificially ventilated patients (eight males), aged 45-74 years were investigated. Blood gases, cardiac output and concentrations of inert gases were measured before and 30 min after infusion of DB or DP. DP and DB were administered alternatively at a rate of 5 micrograms.k-1 min-1. The decrease in PaO2 was significantly greater with DP (12 +/- 9 torr) than with DB (7 +/- 9 torr) (P less than 0.01). Both drugs similarly increased cardiac output: +2.61.min-1 +/- 1.4 for DP and 2.21.min-1 +/- 1.5 for DB. Both DP and DB significantly (P less than 0.01) increased the perfusion of alveoli with VA/Q = 0 (+4 +/- 7% for DP and +3 +/- 7% for DB) and 0 less than VA/Q less than 0.1 (+11 +/- 8.5% for DP and +5.5 +/- 10.5% for DB) (no significant difference between the drugs). When shunt and "shunt-like" effect are considered together, there was a significantly greater increase in the amount of blood going to alveoli with a low VA/Q ratio with DP compared to DB. Both drugs decreased the perfusion of alveoli with 0.1 less than VA/Q less than 10, but the decrease was significantly less for DB than for DP (-15 +/- 6.5% for DP and -8.5 +/- 7% for DB, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
Reassessment of the interruption technique for measuring flow resistance in humans.
We have previously produced evidence that, in patients with obstructive lung disease, compliance of extrathoracic airways is responsible for lack of mouth-to-alveolar pressure equilibration during respiratory efforts against a closed airway. The flow interruption method for measuring respiratory resistance (Rint) is potentially faced with the same problems. We reassessed the merits of the interruption technique by rendering the extrathoracic airways more rigid and by using a rapid shutter. We measured airway resistance (Raw) with whole body plethysmography during panting (at 2 Hz) and Rint during quiet breathing. Rint and Raw were expressed as specific airway (sGaw) and interruptive conductance (sGint), respectively. In nine healthy subjects (cheeks supported), sGint (0.140 +/- 0.050 s-1.cmH2O-1) was lower (P less than 0.02) than sGaw (0.182 +/- 0.043 s-1.cmH2O-1). By contrast, in 12 patients with severe obstructive lung disease (forced expiratory volume in 1 s/vital capacity = 41.0 +/- 19.8%), sGint (0.058 +/- 0.012 s-1.cmH2O-1) was higher (P less than 0.05) than sGaw (0.047 +/- 0.007 s-1.cmH2O-1), when the cheeks were supported. When the mouth floor was also supported, average values of sGaw (0.048 +/- 0.008 s-1.cmH2O-1) and sGint (0.049 +/- 0.014 s-1.cmH2O-1) became similar. In conclusion, we confirm previous findings in healthy subjects of higher values of Rint, with respect to Raw, probably because of differences in glottis opening between quiet breathing and panting. In airflow obstruction, supporting both the cheeks and the mouth floor decreased sGint, which became similar to sGaw.
Adult↗
Head position modifies upper airway resistance in men.
We measured in healthy volunteers airway resistance (R(aw)), resistance of the respiratory system (Rrs), and supralaryngeal resistance (Rsl) in the following head positions: neutral, extended, and partially and fully flexed. Sagittal magnetic resonance images of the upper airways were recorded in neutral and flexed head positions. We observed significant increases in Raw (P less than 0.01), Rrs (P less than 0.001), and Rsl (P less than 0.001) in the flexed position, with respect to the neutral one, and corresponding decreases of specific airway and specific respiratory conductances. Resistances decreased (although not significantly) when the subjects' heads were extended. A decrease in both diameter and surface area of the hypopharyngeal airways (as shown by magnetic resonance images) with total head flexion was accompanied by significant increases in all measured resistances. Changes in the caliber of hypopharynx appear to be responsible for the increase in resistance during head flexion.
Adult↗
The importance of the balloon reservoir volume of a CPAP system in reducing the work of breathing.
We have previously reported, that the work of breathing in spontaneously breathing patients on CPAP could be significantly reduced by increasing the volume of the balloon reservoir in the circuit of a CPAP system from 3 to 23 l. We now report a study designed to determine the optimum balloon reservoir volume for the minimization of the work of breathing. Twenty intubated, spontaneously breathing patients were connected to a CPAP system with interchangeable balloon reservoirs. In each patient the work of breathing was measured for reservoir volumes of 3, 6, 12, 18, and 24 l attached in random order, while the positive airway pressure was held constant at 10 cm H2O. The balloons were constructed of the same material and had similar compliance. Rebreathing was prevented with use of one-way valves. Significant (p less than 0.001) decreases in the work of breathing were found on increasing reservoir volumes from 3 to 6, 6 to 12, and 12 to 18 l. A less significant (p less than 0.01) decrease in the work of breathing was found between reservoirs of 18 and 24 l. Rebreathing did not occur with significantly (p less than 0.001) lower flow rates when large reservoirs were used. We conclude that a balloon reservoir of 18 l represents the best compromise between reduction in the work of breathing, utilization of low source flow, and convenience of clinical use.
Carbon Dioxide↗
Hysteresis of the alveolar capillary membrane in normal subjects.
Weibel and associates (Respir. Physiol. 18: 285-308, 1973), using morphometric techniques, demonstrated in the rat that changes in lung volume related to inflation and deflation caused a hysteretic variation in alveolar capillary membrane which is locally pleated at low pulmonary volume, unfolds during inflation but does not immediately refold during deflation, possibly enhancing the CO diffusion throughout the membrane. The present study was conducted to verify the existence of this hysteresis in human lungs in vivo. Single-breath diffusing capacity for CO (DLCO) was measured in five healthy seated subjects before and 0, 0.5, 1, 3, and 7 min after an inflation-deflation maneuver (IDM) in 6 separate days. The value of mean DLCO was 36.4 +/- 3 (SD) before and 42.1 +/- 2.9, 41.6 +/- 3.3, 40.3 +/- 3.3, 39.2 +/- 3.2, and 38.1 +/- 2.7 ml X min-1 X Torr-1 after the IDM. Two mechanisms can explain our findings: an active filling of the capillary bed, or an unfolding of the alveolar capillary membrane. The first mechanism should be accompanied by changes in pulmonary circulation. Therefore, right-heart catheterization was performed in two normal subjects and in four patients examined for a chest pain syndrome. At the end of the IDM, the values for the pulmonary artery pressure and capillary wedge pressure had returned to control levels. This suggests that the capillary bed is not directly involved in the DLCO increase observed from 0.5 to 7 min after the IDM. The unfolding of the alveolar capillary membrane appears to better explain our findings.(ABSTRACT TRUNCATED AT 250 WORDS)
Blood Volume↗
Elastic properties of the lung in acute induced asthma.
In acute induced asthma, plethysmographic total lung capacity (TLCm) was reported to increase and lung elastic recoil [Pst(L)] to decrease. The increase in TLC is spurious (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 52: 939-954, 1982), so that the rapid loss in Pst(L) could be due to errors in lung volume. We studied seven asthmatic patients before and during an induced bronchospasm. TLC was derived simultaneously from mouth and esophageal pressure vs. plethysmographic volume plots (TLCm and TLCes, respectively). Before bronchospasm, TLCm and TLCes were similar. During bronchospasm average TLCm increased, from 7.30 +/- 1.34 (SD) to 8.12 +/- 1.49 liters (P less than 0.001), whereas TLCes did not (P greater than 0.60). Static pressure-volume curves, derived from TLCes (P-Ves), were superimposed on prechallenge curves or only slightly shifted to the left, whereas those derived from TLCm (P-Vm) showed a clear-cut parallel shift to the left. At 70% of control TLC there was no significant change in Pst(L) measured from P-Ves curves (7.3 +/- 3.1 cmH2O before bronchospasm; 6.7 +/- 2.3 cmH2O during bronchospasm, P greater than 0.10), whereas Pst(L) measured from P-Vm curves decreased from 7.3 +/- 3.1 to 5.1 +/- 2.4 cmH2O (P less than 0.01). No significant change in Pst(L) at TLC was observed during bronchospasm. We conclude that in our patients acute decrease in Pst(L) during induced asthma was artifactual, secondary to lung volume overestimation by body plethysmography.
Acute Disease↗
Mouth spraying versus inhalation of fenoterol aerosol in healthy subjects and asthmatic patients.
Four hundred micrograms of fenoterol aerosol were administered to 10 healthy subjects and nine asthmatic patients. Fenoterol was either inhaled or sprayed into the mouth carefully avoiding inhalation. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1.0), maximal expiratory flow rates (MEFR), specific airways conductance (sGaw), total lung capacity (TLC), residual volume (RV), and heart rate (HR) were measured before and up to one hour after fenoterol administration. FVC, FEV1.0, MEFR and sGaw increased significantly after inhalation of fenoterol in both asthmatic patients and healthy subjects. The increase was significantly greater in the asthmatic group. After buccal administration of fenoterol FVC, FEV1.0 and sGaw increased significantly in both asthmatic patients and healthy subjects, and there was no significant difference between the two groups. Increased heart rate and side effects were observed only in healthy subjects and only after inhalation. Buccal administration of fenoterol to both asthmatic patients and healthy subjects induced a clearcut bronchodilation (though less than that produced by inhalation), probably by absorption of the drug through the oral mucosa.
Adolescent↗
Failure of body plethysmography in bronchial asthma.
To determine whether acute changes in lung volumes in asthma are accurately measured by body plethysmography, we induced acute changes in lung mechanics with acetylcholine in nine asthmatic patients and with salbutamol in six others. Total lung capacity (TLC) was measured with a body plethysmograph and derived from mouth pressure vs. box volume (Vbox) changes (TLCm) or esophageal pressure vs. Vbox changes (TLCes). In six patients (4 after acetylcholine) TLCm was significantly (P less than 0.05) different from prechallenge values (differences ranged from 0.29 to 1.55 liters), but TLCes did not change. In three additional patients both TLCm (mean difference 0.62 liter) and TLCes (mean difference 0.43 liter) changed (P less than 0.05), but no changes occurred in six others. An electrical analog of the lung demonstrates in the presence of intrathoracic airway obstruction overestimation of thoracic gas volume and TLC. This is due to the presence of a compliant extrathoracic airway that acts as a shunt impedance. The magnitude of the overestimation of TGV appears to depend on the distensibility of the extrathoracic airway and the degree of airway obstruction. We conclude that the plethysmographic method may introduce important errors in lung volume measurements in the obstructive syndrome, especially a severe one. Some of previously reported acute increases in TLC in asthmatics may be artifactual.
Acetylcholine↗
Bronchial asthma following exposure to ECG ink.
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Adult↗
Intrathoracic airway mechanics in patients with emphysema.
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Forced Expiratory Volume↗
Effects of vagal blockade on lung mechanics in normal man.
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Adult↗
Sex and age differences in intrathoracic airways mechanics in normal man.
Expiratory pressure-volume curves and maximal expiratory flow-volume curves were obtained in 74 healthy subjects (49 males 25 females) aged between 20 and 64. Maximal expiratory flowstatic recoil (MEFSR) curves were then constructed. Aging was associated with loss of lung recoil and reduction in maximal expiratory flow measured between 80 and 50% total lung capacity (TLC), in both males and females, with the slope of the MEFSR curve becoming steeper. In subjects less than 40 yr old the conductance of the upstream segment increased from 80 to 50% TLC, whereas in older subjects it decreased. We also studied the effects of alveolar gas compression artifacts on MEFSR curves in 12 additional subjects and 10 patients with chronic obstructive lung disease; consistent changes were found, but the subsequent shift of the MEFSR curve toward the left was only mild. These changes are interpreted as reflecting the net effects of an increase in the unstressed dimensions of the airways together with a decrease in intraparenchymal airways diameter, probably due to loss of parenchymal airways diameter, probably due to loss of parenchymal support. It was also concluded that the analysis of the MEFSR curve did not allow a quantitative estimate of the chantes in airways compressibility with aging.
Adult↗
Influence of beta-2 agonist aerosols on pressure-volume characteristics of the lungs.
The effects of inhalation of a beta-2 adrenergic compound (fenoterol) on the expiratory pressure-volume curve of the lung were studied in 11 normal subjects. In particular, the dose dependence and the time course of this effect were determined, and they were compared to the characteristics of the bronchodilator action. Analysis of the results showed that (1) despite a decrease in esophageal tone, lung recoil pressures at all lung volumes were decreased by these compounds, (2) this change, in contrast to bronchodilation, was observed only when high doses were inhaled, and (3) this effect appeared rapidly and elapsed after approximately 30 min, whereas bronchodilation remained stable for at least 2 hours. Additional studies with intravenous infusion of the drug indicated that the effects of beta adrenergic agonists on the pressure-volume characteristics of the lungs are related to the amount of the drug delivered to the peripheral segments of the lung. These findings suggested that large doses of beta-2 agonist aerosols can cause sufficient relaxation of the contractile elements of the lung parenchyma to produce alterations in the static elastic properties of the lungs. In contrast to bronchodilation, which results from a topical action of inhaled particles, these alterations are probably a systemic effect of these aerosols, related to the quantity of the drug absorbed into the circulation.
Adult↗
Pharmacokinetics of oral acetylcysteine: absorption, binding and metabolism in patients with respiratory disorders.
The fate of an oral 100 mg dose of 35S-acetylcysteine, a mucolytic agent, was studied in 10 patients with respiratory disorders, 5 of whom underwent pneumonectomy or lobectomy a few hours after administration of the drug. In the 5 nonoperated patients, plasma radioactivity concentrations were maximal after 2 to 3 hours and remained high after 24 hours; about 22% of radioactivity was excreted in urine after 24 hours. In the 5 operated patients, plasma radioactivity concentrations were comparable with those in the nonoperated patients. Lung tissue radioactivity concentrations after 5 hours were comparable with those in plasma, while the presence of small amounts of radioactivity in the bronchial secretions indicates that acetylcysteine passes into the mucus. Total radioactivity after 5 hours consisted of free, unchanged drug and metabolites (about 22% of total in plasma, 48% in lung tissue), unchanged drug bound to protein by means of labile disulphide bridges (about 14% in plasma, 47% in lung tissue), and drug firmly bound to protein (about 64% in plasma, 5% in lung tissue). Oral acetylcysteine is rapidly absorbed and slowly excreted and is available in the lung in an active form for at least 5 hours at high concentrations.
Acetylcysteine↗
[Orthodontic appliances in the treatment of sleep apnea: a cephalometric and polysomnographic study].
AIM: Effects of oral appliances on snoring in patients with obstructive sleep apnoea syndrome: correlation between cephalometry with and without oral appliance (OA) in place. SUBJECTS: 15 patients were treated with 3 types of OA: Herbst, tooth positioner and QuietKnight. METHODS: All patients underwent a full-night diagnostic polysomnography. They were asked to use their OA each night during one month. All the subjects then underwent a second polysomnography with the OA in place. Standard cephalometric analysis was done in each patient with and without the OA in place. RESULTS: Although average apnea-hypopnea index decreased significantly, snoring was not affected by the OA. Only in 7 patients a reduction was observed. There was a strong correlation between the change in snoring index during sleep and 2 cephalometric variables: ANB angle without, and overjet with the OA in place. No change in quality of sleep was observed. CONCLUSION: OA are indeed effective in decreasing the number of obstructive apneas and hypopneas, without affecting the quality of sleep. Snoring reduction with OA may be predicted by cephalometry.
Analysis of Variance↗