scholarly journals Superior laryngeal nerve section alters responses to upper airway distortion in sleeping dogs

1997 ◽  
Vol 83 (3) ◽  
pp. 768-775 ◽  
Author(s):  
Aidan K. Curran ◽  
Peter R. Eastwood ◽  
Craig A. Harms ◽  
Curtis A. Smith ◽  
Jerome A. Dempsey

Curran, Aidan K., Peter R. Eastwood, Craig A. Harms, Curtis A. Smith, and Jerome A. Dempsey. Superior laryngeal nerve section alters responses to upper airway distortion in sleeping dogs. J. Appl. Physiol. 83(3): 768–775, 1997.—We investigated the effect of superior laryngeal nerve (SLN) section on expiratory time (Te) and genioglossus electromyogram (EMGgg) responses to upper airway (UA) negative pressure (UANP) in sleeping dogs. The same dogs used in a similar intact study (C. A. Harms, C. A., Y.-J. Zeng, C. A. Smith, E. H. Vidruk, and J. A. Dempsey. J. Appl. Physiol. 80: 1528–1539, 1996) were bilaterally SLN sectioned. After recovery, the UA was isolated while the animal breathed through a tracheostomy. Square waves of negative pressure were applied to the UA from below the larynx or from the mask (nares) at end expiration and held until the next inspiratory effort. Section of the SLN increased eupneic respiratory frequency and minute ventilation. Relative to the same dogs before SLN section, sublaryngeal UANP caused less Te prolongation while activation of the genioglossus required less negative pressures. Mask UANP had no effect on Te or EMGgg activity. We conclude that the SLN 1) is not obligatory for the reflex prolongation of Te and activation of EMGgg activity produced by UANP and 2) plays an important role in the maintenance of UA stability and the pattern of breathing in sleeping dogs.

1996 ◽  
Vol 91 (3) ◽  
pp. 337-345 ◽  
Author(s):  
Ken D. O'halloran ◽  
Aidan K. Curran ◽  
Aidan Bradford

1. Ventilation was measured during normoxia, hypoxia and hypercapnia before and after administration of almitrine in conscious, unrestrained, tracheostomized rats with the superior laryngeal nerves intact or cut. In superior laryngeal nerve-intact animals breathing air, almitrine increased minute ventilation due to an increase in respiratory frequency with no change in tidal volume. In superior laryngeal nerve-sectioned animals, the minute ventilatory response to almitrine was reduced due to a reduced tidal volume component of the response. Almitrine increased the ventilatory response to hypercapnia in superior laryngeal nerve-intact but not in sectioned animals. 2. In anaesthetized, vagotomized rats breathing spontaneously through a low-cervical tracheostomy, diaphragm and geniohyoid electromyographic activities were recorded. Arterial blood pressure and rectal temperature were continuously monitored. A single dose of almitrine was administered intravenously. In all animals, the geniohyoid muscle had phasic inspiratory activity which slightly preceded diaphragm activity. Almitrine had no effect on respiratory frequency or inspiratory and expiratory duration but increased mean peak integrated diaphragm (+29.3 ±13.6%) and geniohyoid (+ 132.0 ±21.3%) muscle activity. 3. These results show that almitrine exerts part of its ventilatory effects through superior laryngeal nerve afferents. Almitrine preferentially excites upper airway compared with diaphragm muscle activity, suggesting a potential role in the alleviation of obstructive apnoea.


1984 ◽  
Vol 56 (3) ◽  
pp. 746-752 ◽  
Author(s):  
E. van Lunteren ◽  
W. B. Van de Graaff ◽  
D. M. Parker ◽  
J. Mitra ◽  
M. A. Haxhiu ◽  
...  

The effects of negative pressure applied to just the upper airway on nasal and laryngeal muscle activity were studied in 14 spontaneously breathing anesthetized dogs. Moving average electromyograms were recorded from the alae nasi (AN) and posterior cricoarytenoid (PCA) muscles and compared with those of the genioglossus (GG) and diaphragm. The duration of inspiration and the length of inspiratory activity of all upper airway muscles was increased in a graded manner proportional to the amount of negative pressure applied. Phasic activation of upper airway muscles preceded inspiratory activity of the diaphragm under control conditions; upper airway negative pressure increased this amount of preactivation. Peak diaphragm activity was unchanged with negative pressure, although the rate of rise of muscle activity decreased. The average increases in peak upper airway muscle activity in response to all levels of negative pressure were 18 +/- 4% for the AN, 27 +/- 7% for the PCA, and 122 +/- 31% for the GG (P less than 0.001). Rates of rise of AN and PCA electrical activity increased at higher levels of negative pressure. Nasal negative pressure affected the AN more than the PCA, while laryngeal negative pressure had the opposite effect. The effects of nasal negative pressure could be abolished by topical anesthesia of the nasal passages, while the effects of laryngeal negative pressure could be abolished by either topical anesthesia of the larynx or section of the superior laryngeal nerve. Electrical stimulation of the superior laryngeal nerve caused depression of AN and PCA activity, and hence does not reproduce the effects of negative pressure.(ABSTRACT TRUNCATED AT 250 WORDS)


2020 ◽  
Vol 10 (4) ◽  
Author(s):  
Parviz Amri ◽  
Novin Nikbakhsh ◽  
Seyed Reza Modaress ◽  
Ramin Nosrati

Background: Rigid bronchoscopy is often used to diagnose and treat the location of resection of the tracheal stenosis. It is a selective procedure for the dilatation of tracheal stenosis, especially when accompanied by respiratory distress. Objectives: We introduced patients who were diagnosed with tracheal stenosis and candidate for rigid bronchoscopy dilatation by the upper airway nerve blocks. Methods: This prospective observational study was conducted on 17 patients who underwent dilatation with rigid bronchoscopy in tracheal stenosis at Hospitals affiliated with Babol University of Medical Sciences from 2002 to 2017. The patients were given three nerve blocks, 6 bilateral superior laryngeal nerve block, bilateral glossopharyngeal nerve block, and recurrent laryngeal nerve block (transtracheal) before awake rigid bronchoscopy using 2% lidocaine. We evaluated the demographic data, the cause of tracheal stenosis, the quality of the airway nerve block (Intubation score), patients’ satisfaction from bronchoscopy and thoracic surgeons’ satisfaction. Complications of nerve blocks were recorded. Results: From 2002 to 2017, 17 patients (14 were male and 3 were) female with tracheal stenosis who were candidates for dilatation with bronchoscopy and accepted the upper nerve block were included. The quality of the block was acceptable in 16 (94%) patients. 15 patients received fentanyl, and only two patients did not need to intravenous sedation. The mean age of patients was 29.59 ± 11.59. The average satisfaction of the surgeon was 8.82 ± 1.13 and the satisfaction of patients with anesthesia was 8.89 ± 1.16. There was one serious complication (laryngospasm) in one patient. Conclusions: The upper airway nerve block method is a suitable anesthesia technique for patients with tracheal stenosis who are candidates for the tracheal dilatation with rigid bronoscopy, especially when the patient has respiratory distress and has not been evaluated before surgery.


1989 ◽  
Vol 98 (5) ◽  
pp. 373-378 ◽  
Author(s):  
Gayle E. Woodson

The cricothyroid muscle (CT) appears to be an accessory muscle of respiration. Phasic inspiratory contraction is stimulated by increasing respiratory demand. Reflex activation of the CT may be responsible for the paramedian position of the vocal folds, and hence airway obstruction, in patients with bilateral recurrent laryngeal nerve (RLN) paralysis. Previous research has demonstrated the influence of superior laryngeal nerve (SLN) afferents on CT activity. The present study addresses the effects of vagal and RLN afferents. Electromyographic activity of the CT and right posterior cricoarytenoid muscle was monitored in anesthetized cats during tracheotomy breathing and in response to tracheal or upper airway occlusion in the intact animal. This was repeated following left RLN transection, bilateral vagotomy, and bilateral SLN transection. Vagotomy abolished CT response to tracheal occlusion and markedly reduced the response to upper airway occlusion. Vocal fold position following RLN transection appeared to correlate with CT activity; however, observed changes were minor.


2002 ◽  
Vol 92 (1) ◽  
pp. 269-278 ◽  
Author(s):  
Stephen Ryan ◽  
Walter T. McNicholas ◽  
Ronan G. O'Regan ◽  
Philip Nolan

10.1152/japplphysiol.00413.2001.—Distortion of the upper airway by negative transmural pressure (UANP) causes reflex vagal bradycardia. This requires activation of cardiac vagal preganglionic neurons, which exhibit postinspiratory (PI) discharge. We hypothesized that UANP would also stimulate cranial respiratory motoneurons with PI activity. We recorded 32 respiratory modulated motor units from the recurrent laryngeal nerve of seven decerebrate paralyzed rabbits and recorded their responses to UANP and to withholding lung inflation using a phrenic-triggered ventilator. The phasic inspiratory ( n = 17) and PI ( n = 5) neurons detected were stimulated by −10 cmH2O UANP and by withdrawal of lung inflation ( P < 0.05, Friedman's ANOVA). Expiratory-inspiratory units ( n = 10) were tonically active but transiently inhibited in postinspiration; this inhibition was more pronounced and prolonged during UANP stimuli and during no-inflation tests ( P < 0.05). We conclude that, in addition to increasing inspiratory activity in the recurrent laryngeal nerve, UANP also stimulates units with PI activity.


PEDIATRICS ◽  
1983 ◽  
Vol 71 (4) ◽  
pp. 634-638
Author(s):  
Manuel Durand ◽  
Ellen McCann ◽  
June P. Brady

The effect of continuous positive airway pressure (CPAP) on the ventilatory response to CO2 in newborn infants is unknown. The CO2 response to 4% CO2 in air was studied in nine preterm infants without lung disease before and during administration of CPAP (4 to 5 cm H2O) delivered by face mask. Minute ventilation, tidal volume, respiratory frequency, and end-tidal Pco2 were measured, and the slope and intercept of the CO2 response were calculated. Respiratory pattern and changes in oxygenation were also analyzed by measuring inspiratory and expiratory time, mean inspiratory flow, mean expiratory flow, effective respiratory timing, endtidal Po2, and transcutaneous Po2. CPAP significantly decreased minute ventilation from 278.7 to 197.6 mL/mm/kg (P &lt; .001). Tidal volume and respiratory frequency were also significantly decreased. The slope of the CO2 response during CPAP was not significantly different from the slope before CPAP (36 v 33 mL/min/kg/mm Hg, P &gt; .1), but the intercept was shifted to the right (P &lt; .001). The decrease in respiratory frequency was primarily due to a prolongation of expiratory time (P &lt; .05). In addition, transcutaneous Po2 increased during administration of CPAP (P &lt; .001). These findings indicate that: (1) CPAP significantly decreases ventilation in preterm infants without lung disease, affecting both tidal volume and respiratory frequency; (2) CPAP does not appreciably alter the ventilatory response to CO2; (3) the changes in respiratory frequency are primarily accounted for by a prolongation of expiratory time; (4) CPAP improves oxygenation.


2005 ◽  
Vol 114 (4) ◽  
pp. 271-275 ◽  
Author(s):  
Clarence T. Sasaki ◽  
Jagdeep S. Hundal ◽  
Young-Ho Kim

Glottic closure constitutes the primary mechanism for prevention of intradeglutitive and postdeglutitive aspiration. Laryngeal paralysis therefore exerts a considerable impact on deglutition, yet little is understood regarding the biomechanical effects of selective denervation on the laryngeal protective function. We measured the glottic closing force (GCF) in each of 6 male, 40-kg Yorkshire pigs 1) after selective unilateral superior laryngeal nerve (SLN) section; 2) after selective unilateral recurrent laryngeal nerve (RLN) section; and/or 3) after combined SLN-RLN section as both right and left SLNs were simultaneously stimulated to evoke the glottic closure response. Stimulation was provided through an oscilloscope with bipolar platinum-iridium electrodes, and the GCF was measured with a pressure transducer positioned between the vocal cords. Six repetitive measures of GCF were obtained before nerve section, and 6 after nerve section, in each subject. Unilateral SLN section reduced the GCF to 54.14% of control, RLN section reduced the GCF to 23.39% of control, and combined SLN-RLN section reduced the GCF to 22.67% of control. These findings underscore the profound differential effects exerted by isolated lesions on the glottic closure function.


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