scholarly journals Laryngeal response to nasal ventilation in nonsedated newborn lambs

2007 ◽  
Vol 102 (6) ◽  
pp. 2149-2157 ◽  
Author(s):  
François Moreau-Bussière ◽  
Nathalie Samson ◽  
Marie St-Hilaire ◽  
Philippe Reix ◽  
Joëlle Rouillard Lafond ◽  
...  

Although endoscopic studies in adult humans have suggested that laryngeal closure can limit alveolar ventilation during nasal intermittent positive pressure ventilation (nIPPV), there are no available data regarding glottal muscle activity during nIPPV. In addition, laryngeal behavior during nIPPV has not been investigated in neonates. The aim of the present study was to assess laryngeal muscle response to nIPPV in nonsedated newborn lambs. Nine newborn lambs were instrumented for recording states of alertness, electrical activity [electromyograph (EMG)] of glottal constrictor (thyroarytenoid, TA) and dilator (cricothyroid, CT) muscles, EMG of the diaphragm (Dia), and mask and tracheal pressures. nIPPV in pressure support (PS) and volume control (VC) modes was delivered to the lambs via a nasal mask. Results show that increasing nIPPV during wakefulness and quiet sleep led to a progressive disappearance of Dia and CT EMG and to the appearance and subsequent increase in TA EMG during inspiration, together with an increase in trans-upper airway pressure (TUAP). On rare occasions, transmission of nIPPV through the glottis was prevented by complete, active glottal closure, a phenomenon more frequent during active sleep epochs, when irregular bursts of TA EMG were observed. In conclusion, results of the present study suggest that active glottal closure develops with nIPPV in nonsedated lambs, especially in the VC mode. Our observations further suggest that such closure can limit lung ventilation when raising nIPPV in neonates.

2008 ◽  
Vol 105 (5) ◽  
pp. 1406-1412 ◽  
Author(s):  
Bianca Roy ◽  
Nathalie Samson ◽  
François Moreau-Bussière ◽  
Alain Ouimet ◽  
Dominique Dorion ◽  
...  

The present study stems from our recent demonstration (Moreau-Bussiere F, Samson N, St-Hilaire M, Reix P, Lafond JR, Nsegbe E, Praud JP. J Appl Physiol 102: 2149–2157, 2007) that a progressive increase in nasal intermittent positive pressure ventilation (nIPPV) leads to active glottal closure in nonsedated, newborn lambs. The aim of the study was to determine whether the mechanisms involved in this glottal narrowing during nIPPV originate from upper airway receptors and/or from bronchopulmonary receptors. Two groups of newborn lambs were chronically instrumented for polysomnographic recording: the first group of five lambs underwent a two-step bilateral thoracic vagotomy using video-assisted thoracoscopic surgery (bilateral vagotomy group), while the second group, composed of six lambs, underwent chronic laryngotracheal separation (isolated upper airway group). A few days later, polysomnographic recordings were performed to assess glottal muscle electromyography during step increases in nIPPV (volume control mode). Results show that active glottal narrowing does not develop when nIPPV is applied on the upper airways only, and that this narrowing is prevented by bilateral vagotomy when nIPPV is applied on intact airways. In conclusion, active glottal narrowing in response to increasing nIPPV originates from bronchopulmonary receptors.


1986 ◽  
Vol 14 (3) ◽  
pp. 258-266 ◽  
Author(s):  
P. D. Cameron ◽  
T. E. Oh

Recent modes of ventilatory support aim to facilitate weaning and minimise the physiological disadvantages of intermittent positive pressure ventilation (IPPV). Intermittent mandatory ventilation (IMV) allows the patient to breathe spontaneously in between ventilator breaths. Mandatory minute volume ventilation (MMV) ensures that the patient always receives a preset minute volume, made up of both spontaneous and ventilator breaths. Pressure supported (assisted) respiration is augmentation of a spontaneous breath up to a preset pressure level, and is different from ‘triggering’, which is a patient-initiated ventilator breath. Other modes or refinements of IPPV include high frequency ventilation, expiratory retard, differential lung ventilation, inversed ratio ventilation, ‘sighs’, varied inspiratory flow waveforms and extracorporeal membrane oxygenation. While these techniques have useful applications in selective situations, IPPV remains the mainstay of managing respiratory failure for most patients.


Author(s):  
Margarita Vyzhigina ◽  
Viktor Titov ◽  
Svetlana Zhukova ◽  
Oksana Kurilova

Anaesthesiological Maintenance of Patients with Obesity Pathophysiological features of morbid obesity and the associated functional-anatomical changes in an organism demand the special approach to anaesthesiological maintenance. Methods of anaesthesiological protection and maintenance of effective gas exchange in morbide obesity patients have been proved. Anaesthesias for 110 patients have been analysed. Multicomponent anesthesia with traditional and combined artificial lung ventilation (ALV) (IPPV+HFJV) (intermittent positive pressure ventilation and high frequency jet ventilation) was used. Since 2000, morbid obesity patients receive intubation only with fibrobronchoscope with self breathing under local anesthesia. In IPPV for morbid obesity patients high peak pressure in airways, low V/Q, and low PaO2 occurs. Technology of combined ALV (IPPV+HFJV) has led to pressure decrease in airways and to effective arterial oxygenation improvement, intrapulmonary shunt has decreased. Retrospective analysis of anesthesia components revealed that the applied anaesthetic doses correspond to calculations on ideal body weight, and not true weight. Thus, anaesthesiological maintenance of operated patients with morbid obesity requires trachea intubation with fibroscope under local anaesthesia with self-breathing; high efficiency of ALV methods, allowing lower pressure in airways and high oxygenation (IPPV+HFJV), which provides effective gas exchange; doses correction of intravenous anaesthetics for due body weight is required.


2021 ◽  
Vol 17 (8) ◽  
pp. 51-54
Author(s):  
R.O. Merza ◽  
Ya.M. Pidhirnyi

Background. One of the main technologies of modern anesthesiology is mechanical ventilation (MV). At present, the protective technology of MV is widely recognized. The feasibi-lity of using this technology in the operating room, especially in patients with intact lungs, is not so obvious. Most of the scientific sources that cover this problem relate to patients with abdominal pathology, and less coverage remains in patients with neurosurgical pathology. However, patients who are operated on for neurosurgical pathology belong to the group of patients of high surgical risk, which forced us to conduct this study. The study was aimed to examine the feasibility of using protective MV during surgery in neurosurgical patients. Materials and methods. We examined 46 patients who were hospitalized in KNP 8 MKL in Lviv for spinal pathology and who underwent surgery for vertebroplasty with spondylodesis. Patients were divided into two groups: in the first group (34 patients), MV was performed by S-IPPV technology — synchronized intermittent positive pressure ventilation with volume control; and in the second group (12 patients), MV was performed by PCV technology — controlled ventilation pressure. Results. We retrospectively determined the incidence of post-operative pulmonary complications (POPC) in patients of the first and second groups. Of the 34 patients of the first group, the signs of POPC were detected in 17 patients (50 %), and of 12 patients of the second group, POPC were detected in 4 patients (33.3 %). It should be noted that MV in patients of both groups did not differ in such parameters as respiratory rate, end-alveolar pressure, and the fraction of oxygen in the respiratory mixture. Conclusions. A relatively small number of patients clearly do not allow the conclusions to be drawn, but it should be noted that MV (especially volume-controlled) contributes to postoperative pulmonary complications in patients with intact lungs in the preoperative period. And pressure-controlled MV tends to reduce the incidence of postoperative pulmonary complications in the postoperative period. Given that respiration rate, end-alveolar expiratory pressure and oxygen fraction in the respiratory mixture were comparable in patients of both groups, it can be assumed that the factor influencing the incidence of POPC is the mechanics of pulmonary ventilation.


Author(s):  
Yuan Lei

‘Lung Ventilation: Natural and Mechanical’ describes the processes of respiration and lung ventilation, focusing on those issues related directly to mechanical ventilation. The chapter starts by discussing the anatomy and physiology of respiration, and the involvement of the lungs and the entire respiratory system. It continues by introducing the three operating principles of mechanical ventilation. It then narrows its focus to intermittent positive pressure ventilation (IPPV), the operating principle of most modern critical care ventilators, explaining the pneumatic process of IPPV. The chapter ends by comparing natural and mechanical/artificial lung ventilation.


1986 ◽  
Vol 14 (3) ◽  
pp. 226-235 ◽  
Author(s):  
D. R. Hillman

The mechanical properties of the lungs and chest wall dictate the relationship between tidal volume, flow rate and airway pressure developed during intermittent positive pressure ventilation (IPPV). The increase in intrathoracic pressures associated with IPPV has consequences for the intrapulmonary distribution of ventilation and perfusion (hence gas exchange), cardiac output and regional blood flows. Barotrauma is a potential hazard. IPPV also affects the homeostatic mechanisms that keep the air spaces dry. Strategies to maximise the benefits and minimise the side effects of IPPV include positive end-expiratory pressure, intermittent mandatory ventilation, differential lung ventilation and high frequency ventilation. Understanding the physiological effects of IPPV and associated therapies allows a rational approach to the adjustment of ventilation against pulmonary, cardiovascular and systemic responses so as to optimise gas exchange and peripheral oxygen delivery.


2005 ◽  
Vol 99 (5) ◽  
pp. 1636-1642 ◽  
Author(s):  
Nathalie Samson ◽  
Marie St-Hilaire ◽  
Elise Nsegbe ◽  
Philippe Reix ◽  
François Moreau-Bussière ◽  
...  

The present study was aimed at investigating the effects of nasal continuous positive airway pressure (nCPAP; 6 cmH2O) or intermittent positive pressure ventilation (nIPPV; 10/4 cmH2O) on nonnutritive swallowing (NNS) and on the coordination between NNS and phases of the respiratory cycle, while taking into account the potential effects of states of alertness. Twelve full-term lambs were chronically instrumented at 48 h after birth for polysomnographic recordings, including NNS, diaphragm electromyographic activity, respiratory movements, pulse oximetry, and states of alertness. Studies in control conditions, with nCPAP and nIPPV, were performed in random order in nonsedated lambs at 4, 5, and 6 days of life. Results demonstrate that nCPAP significantly decreased overall NNS frequency, more specifically isolated NNS during quiet sleep and bursts of NNS in active sleep. In comparison, the effects of nIPPV on NNS frequency were more variable, with an inhibition of NNS only in wakefulness and an increase in isolated NNS frequency in active sleep. In addition, neither nCPAP nor nIPPV disrupted the coordination between NNS and phases of the respiratory cycle. In conclusion, nCPAP inhibits NNS occurrence in newborn lambs. Clinical relevance of this novel finding is related to the importance of NNS for clearing the upper airways from secretions and gastric content frequently regurgitated in the neonatal period.


2012 ◽  
Vol 113 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Mohamed Amine Hadj-Ahmed ◽  
Nathalie Samson ◽  
Marie Bussières ◽  
Jennifer Beck ◽  
Jean-Paul Praud

In nonsedated newborn lambs, nasal pressure support ventilation (nPSV) can lead to an active glottal closure in early inspiration, which can limit lung ventilation and divert air into the digestive system, with potentially deleterious consequences. During volume control ventilation (nVC), glottal closure is delayed to the end of inspiration, suggesting that it is reflexly linked to the maximum value of inspiratory pressure. Accordingly, the aim of the present study was to test whether inspiratory glottal closure develops at the end of inspiration during nasal neurally adjusted ventilatory assist (nNAVA), an increasingly used ventilatory mode where maximal pressure is also reached at the end of inspiration. Polysomnographic recordings were performed in eight nonsedated, chronically instrumented lambs, which were ventilated with progressively increasing levels of nPSV and nNAVA in random order. States of alertness, diaphragm, and glottal muscle electrical activity, tracheal pressure, Spo2, tracheal PetCO2, and respiratory inductive plethysmography were continuously recorded. Although phasic inspiratory glottal constrictor electrical activity appeared during nPSV in 5 of 8 lambs, it was never observed at any nNAVA level in any lamb, even at maximal achievable nNAVA levels. In addition, a decrease in Pco2 was neither necessary nor sufficient for the development of inspiratory glottal constrictor activity. In conclusion, nNAVA does not induce active inspiratory glottal closure, in contrast to nPSV and nVC. We hypothesize that this absence of inspiratory activity is related to the more physiological airway pressurization during nNAVA, which tightly follows diaphragm electrical activity throughout inspiration.


Author(s):  
Bayane Sabsabi ◽  
Ava Harrison ◽  
Laura Banfield ◽  
Amit Mukerji

Objective The study aimed to systematically review and analyze the impact of nasal intermittent positive pressure ventilation (NIPPV) versus continuous positive airway pressure (CPAP) on apnea of prematurity (AOP) in preterm neonates. Study Design In this systematic review and meta-analysis, experimental studies enrolling preterm infants comparing NIPPV (synchronized, nonsynchronized, and bi-level) and CPAP (all types) were searched in multiple databases and screened for the assessment of AOP. Primary outcome was AOP frequency per hour (as defined by authors of included studies). Results Out of 4,980 articles identified, 18 studies were included with eight studies contributing to the primary outcome. All studies had a high risk of bias, with significant heterogeneity in definition and measurement of AOP. There was no difference in AOPs per hour between NIPPV versus CPAP (weighted mean difference = −0.19; 95% confidence interval [CI]: −0.76 to 0.37; eight studies, 456 patients). However, in a post hoc analysis evaluating the presence of any AOP (over varying time periods), the pooled odds ratio (OR) was lower with NIPPV (OR: 0.46; 95% CI: 0.32–0.67; 10 studies, 872 patients). Conclusion NIPPV was not associated with decrease in AOP frequency, although demonstrated lower odds of developing any AOP. However, definite recommendations cannot be made based on the quality of the published evidence. Key Points


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