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Query: UMLS:C0010200 (cough)
 23,843 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Because of the close anatomic and physiologic relationship between the heart and lungs, patients with chronic obstructive lung disease are at special risk of arrhythmias. Effective therapy hinges on identifying the mechanisms of the arrhythmias--hemodynamic, metabolic, or drug-induced. Impulsive use of antiarrhythmic agents may result only in a more complex and dangerous rhythm disorder. Extremes of pH are a major cause of arrhythmias in these patients. Respiratory alkalemia usually originates with inappropriate ventilation, often during mechanical respiration, while metabolic alkalemia generally can be traced to diuretic or bicarbonate therapy. Lidocaine or diphenylhydantoin are of little use, since the alkaline pH inside and outside heart muscle cells hampers drug distribution and activity. At the other extreme, the arrhythmias of acidemia strike patients who have severe respiratory failure with carbon dioxide retention or severe cardiac failure with shock and lactic acidemia. Arrhythmias may develop if vagal restraint is lost, which is especially likely in patients with potassium depletion. Irritant receptors along the bronchopulmonary tree can trigger arrhythmias if stimulated by cough, microembolism, or mechanical irritation, which is a hazard with endotracheal or tracheostomy tubes.
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PMID:Mechanisms of arrhythmias in chronic obstructive lung disease. 1 Feb 30

Airway reflexes are difficult to study in conscious animals because associated changes in ventilation alter intrathoracic airway dimensions. By studying an isolated segment of extrathoracic trachea, we have overcome this problem. In each of 2 dogs, we created surgically an isolated tracheal segment just below the larynx, sealed at one end and tapered at the other to a 3-mm opening via a skin fistula. A chronic tracheostomy was also created near the thoracic outlet. We monitored intraluminal pressure (Pseg) of the isolated segment to reflect changes in smooth muscle tone. During anesthesia, with pentobarbital, gentle mechanical stimulation of the carina, deflation of the lungs, and asphyxia for one min increased Pseg (+9 to +/- 16 cm H2O). Lung inflation and alveolar hyperventilation decreased Pseg (-9 to -16 cm H2O). Five breaths of 2 per cent histamine aerosol increased Pseg (+5 cm H2O) when resting tone was normal. We also coated lumen of the isolated segment with tantalum powder and documented roentgenologically changes in the size of the segment that reflected changes in smooth muscle tone; constriction and dilation in response to asphyxia and lung inflation, respectively, were demonstrated directly by this technique. In conscious dogs, lung inflation decreased Pseg, and carinal stimulation increased Pseg. Instillation of lidocaine hydrochloride (Xylocaine) into the isolated tracheal segment blocked cough caused by mechanical stimulation of the segment, but carinal stimulation still caused constriction of the segment under these conditions which indicated that afferent, but not effrent parasympathetic innervation of the segment had been blocked selectively. Conversely, instillation of atropine sulfate into the isolated tracheal segment blocked constriction of the segment caused by carinal stimulation, but mechanical stimulation of the segment still caused cough under these conditions, which indicated that efferent, but not afferent parasympathetic innervation of the segment had been blocked selectively. We conclude that an innervated extrathoracic tracheal segment constricts and dilates via cholinergic pathways and is suitable for the study of airway reflexes in conscious dogs.
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PMID:A chronic isolated tracheal segment to study airway reflexes in conscious dogs. 46 75

We have evaluated the properties of capsaicin as a selective cough-inducing agent in healthy human subjects. Despite frequent coughing, the subjects could inhale repeated breaths of capsaicin aerosol during 60 s without difficulty. Cough started immediately on inhalation and was most intense during the first 30 s. Cough always disappeared promptly when the capsaicin inhalation was terminated. The cough response was well reproducible and concentration-dependent up to 10 microM; at higher concentrations there was a distinct plateau of the cough response. Specific airway conductance was not changed 3 min after 50 microM capsaicin. Capsaicin (> or = 10 microM) had a burning taste, but there were no visual signs of pharyngitis or laryngitis. Citric acid (nebulized solutions 0.125 to 32%) had a choking effect and could be administered only as single breaths. There was no correlation between the cough response to citric acid and to capsaicin. Inhaled lidocaine (20 and 80 mg from nebulized solutions) caused a dose-dependent inhibition of capsaicin-induced cough. Lidocaine suppressed citric acid-induced cough as effectively as capsaicin-induced cough. In conclusion, we have characterized capsaicin-induced cough and demonstrated that it can be a useful tool in the study of cough reactivity and for evaluation of antitussive agents in humans. Capsaicin may be complementary to citric acid and may offer experimental advantages over this traditional tussive stimulus.
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PMID:Capsaicin-induced cough in humans. 148 23

In guinea-pigs citric acid-induced cough and bronchoconstriction were inhibited by beta 2-agonist and xanthine drugs. Lidocaine inhibited only cough. Cromoglycate and ipratropium bromide inhibited only bronchoconstriction. We conclude that cough and bronchoconstriction in guinea-pigs are distinct reflexes and that the inhibitory pharmacology of these airway reflexes may agree in many respects, with that observed in asthmatic subjects.
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PMID:Selective inhibition of cough and bronchoconstriction in conscious guinea pigs. 153 22

Smooth emergence from general endotracheal anesthesia is frequently complicated by coughing induced by stimulation from an endotracheal tube. Lidocaine and other local anesthetics have been shown to anesthetize important rapidly adpating stretch receptors in the dog trachea. With the aim of providing a reservoir for continuous lidocaine release to adjacent tracheal tissue, we examined the ability of clinically used concentrations of lidocaine to diffuse across a commonly used endotracheal tube cuff. Cuffs were filled with either 2% or 4% lidocaine and placed in a 200 mL bath with samples drawn at time intervals up to 360 minutes. Samples were then analyzed for lidocaine concentration. Another set of endotracheal tube cuffs were prefilled for one or 2.5 hours with 2% or 4% lidocaine, emptied, and then refilled with 2% lidocaine. They were then bathed and sampled as above. Cuffs exposed to 4% lidocaine during the prefilling or the diffusion stages resulted in significantly higher concentrations of lidocaine in the baths throughout the time course of the experiment, although all groups demonstrated a rise in the concentration of lidocaine in the baths with time. The highest concentration obtained was 17.49 +/- 2.03 micrograms/mL after 360 minutes. We conclude lidocaine diffuses across endotracheal tube cuffs in a fashion that may enable the cuff to serve a potentially useful role as a reservoir for local anesthetic. This in turn appears to have the potential to smooth emergence from general endotracheal anesthesia in those patients in whom tracheal stimulation may be a complicating factor.
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PMID:In vitro diffusion of lidocaine across endotracheal tube cuffs. 227 11

Cough and airway constriction are common features of respiratory diseases. Both can be caused by stimulation of airway nerves. We have studied the effects of airway anaesthesia on these reflexes, stimulated by inhaled capsaicin, in order to determine whether they are controlled by the same sensory nerves. Ten volunteers had capsaicin cough dose responses performed before and at 10 min after inhaling placebo (ascorbic acid in saline), and the topical anaesthetics lignocaine 40 mg, and dyclonine 8 and 4 mg. The effect of the drugs on respiratory resistance (Rrs), measured using a forced oscillation technique, was measured both before and after the inhalation of a dose of capsaicin which caused less than two coughs. Lignocaine (40 mg) and dyclonine (8 mg) caused significant reports of oral anaesthesia but only lignocaine reduced the cough response to inhaled capsaicin, increasing the log dose of capsaicin causing three or more coughs by 162%. None of the treatments altered basal Rrs or its increase after inhaled capsaicin. Thus, the cough and reflex bronchoconstriction caused by inhaled capsaicin have different sensitivities to inhaled local anaesthesia, suggesting that the effect may be mediated by different sensory pathways.
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PMID:Separation of cough and reflex bronchoconstriction by inhaled local anaesthetics. 237 53

We evaluated the safety and efficacy of high-dose topical and nebulized airway anesthesia in normal volunteers and in patients undergoing diagnostic fiberoptic bronchoscopy. Lidocaine solution (4 percent) was used for gargling, for spraying the palate and oropharynx with an atomizer, and for nebulization with an air-powered nebulizer (mean total dose, 1,682 mg) and 2 percent lidocaine (Xylocaine) jelly for anesthetizing nasal passages. In six normal subjects and in eight patients, lidocaine blood levels were measured at baseline, after gargling, after spraying, after nebulization, and then at 5, 10, 15, 30, and 60 min; 19 normal subjects and ten patients underwent the same anesthesia protocol but had no blood drawn. Fiberoptic bronchoscopy was performed in 21 normal volunteers and in 18 patients and cultures obtained using the protected specimen brush. Additional endobronchial lidocaine (mean 256 mg) was given to the 18 patients after collecting the microbiology specimens. Peak lidocaine blood levels remained below 6 micrograms/ml in all cases. Cough and discomfort during bronchoscopic examination was absent or minimal in 17 of 21 normal subjects (80 percent) and in 14 of 18 patients (77 percent) and was severe in only one instance (5 percent). There were no related complications. Using only topical and nebulized anesthesia is safe and effective for performing fiberoptic bronchoscopy, especially when bacterial cultures are to be obtained and endobronchial instillation of lidocaine must be avoided.
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PMID:Safety and efficacy of using high-dose topical and nebulized anesthesia to obtain endobronchial cultures. 291 78

Topically and intravenously administered local anaesthetic agents are widely used to inhibit cough, but little quantitative, pharmacological data seems to be available. Various aspects of local anaesthetic agents as inhibitors of cough and other airway reflexes are discussed. Nebulized lidocaine dose-dependently inhibited both mechanically (trachea, carina) and ammonia vapour-induced cough. Lidocaine had a similar potency on each type of cough but inhibited that caused by mechanical stimulation for a significantly longer period of time. This observation supports the hypothesis of a more peripheral location for receptors mediating chemical cough. Nebulized tetracaine appeared to be more potent and to have a significantly longer duration of action than lidocaine. The Hering-Breuer inflation reflex was attenuated by both agents and in doses larger than those needed to inhibit cough. This observation is compatible with the view that the cough receptors are located close to the airway lumen and those mediating the Hering-Breuer reflex within the smooth muscle. Airway anaesthesia is commonly used to block the cough reflex during endoscopic procedures. Nebulized lidocaine has been reported also to suppress severe chronic cough but further studies on airway anaesthesia and cough in acute and chronic lung disease are warranted.
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PMID:Airway anaesthesia and the cough reflex. 331 Dec 42

The influence of laryngoscopy and intubation with or without topical lidocaine anesthesia on the endocrine stress response was investigated in six groups of 40 orthopedic surgery patients differing in premedication and technique of lidocaine application (one- or two-step method). Controls were included without lidocaine application. Plasma levels of catecholamines (by HPLC) were measured before induction and 1, 5, and 10 min after intubation, ADH-levels (by RIA) before induction and 5 and 10 min after intubation. In addition, mean arterial pressure (MAP, MAP), HR, and the incidence of coughing and cardiac arrhythmias were observed. The statistical evaluation (analysis of variance with repeated measures on one factor) considered P values of less than 0.05 significant. There was no influence of laryngoscopy and intubation on plasma catecholamine levels during the observation period. A continuous decrease in both levels of epinephrine and norepinephrine was significant. ADH levels showed no significant changes. Lidocaine had no influence on these endocrine parameters. MAP and HR increased after intubation in all groups studied. The increase in HR was less pronounced after lidocaine treatment. Coughing (4 patients) and ventricular dysrhythmia (2 patients) were observed only in patients without lidocaine treatment. In conclusion, no influence of different modes of treatment on the endocrine stress response during intubation became obvious. There was no indication that the cardiovascular symptoms during laryngoscopy and intubation are caused by systemic stress. An explanation may be a direct neural impulse via sympathetic efferents to the heart. On the other hand, topical application of lidocaine did prevent coughing and cardiac irritation, and the increase in HR was attenuated.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The endocrine stress-reaction to orotracheal intubation and topical anesthesia with lidocaine]. 368 17

We studied the relationship between cough and bronchoconstriction caused by inhaled distilled water aerosol in 8 subjects with asthma by measuring specific airways resistance (SRaw) and recording cough while subjects breathed serially increasing volumes of distilled water or normal saline aerosol produced by an ultrasonic nebulizer. We performed the distilled water dose-response curves after no treatment and after treatment with cromolyn aerosol, lidocaine aerosol, or atropine aerosol in doses of 0.2 mg and 2.0 mg on separate days. Without prior treatment, distilled water aerosol caused cough in 7 of 8 subjects and a marked increase in SRaw in every subject, whereas saline aerosol did not cause cough or a greater than 50% increase in SRaw in any subject. The 2 doses of atropine caused an equivalent reduction in baseline SRaw, but 2.0 mg caused greater inhibition of water-induced bronchoconstriction than did 0.2 mg. Neither dose of atropine inhibited cough. These data suggest that water-induced bronchoconstriction involves cholinergic nerves and that water-induced cough is not dependent on bronchoconstriction. Lidocaine inhibited cough but not bronchoconstriction, whereas cromolyn inhibited bronchoconstriction but not cough, suggesting that cromolyn does not inhibit bronchoconstriction by a generalized inhibition of airway afferent nerves.
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PMID:Mechanism of cough and bronchoconstriction induced by distilled water aerosol. 640 71


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