scholarly journals The lciryngeal tube and pharyngeal mucosal pressure

2003 ◽  
Vol 50 (5) ◽  
pp. 525-526 ◽  
Author(s):  
Adrian A. Matioc ◽  
George Arndt
Keyword(s):  
Mucosal Pressure

Pharyngeal Mucosal Pressure and Perfusion 

1999 ◽  
Vol 91 (6) ◽  
pp. 1661-1661 ◽  
Author(s):  
Joseph Brimacombe ◽  
Christian Keller ◽  
Fritz Pühringer
Keyword(s):  
Blood Vessel ◽  
Cuff Volume ◽  
Pharyngeal Mucosa ◽  
Mucosal Perfusion ◽  
The Mean ◽  
Digitized Images ◽  
Sealing Pressure ◽  
Posterior Pharynx ◽  
Mucosal Pressure

Background Pharyngeal airway devices can exert substantial pressures against the pharyngeal mucosa. The authors assess the relation between pharyngeal mucosal perfusion and directly measured mucosal pressure (MP) in the posterior pharynx using a fiberoptic technique with a modified cuffed oropharyngeal airway (COPA). The authors also measure in vivo intracuff pressure (CP), airway sealing pressure and MP at four locations using an unmodified COPA. Methods Twenty adult patients, American Society of Anesthesiologists status I or II, undergoing general anesthesia were allocated randomly to receive either (1) a COPA with a millimeter microchip sensor fixed on the external cuff surface to record distal posterior pharyngeal MP or (2) a COPA with a fiberoptic scope inserted inside the cuff to record digitized images of the distal posterior pharyngeal mucosa. MP and digitized images were obtained at the same location over an in vivo CP range of 10-160 cm H2O in 10- to 20-cm H2O increments. The digitized images were scored according to blood vessel caliber and mucosal color by two investigators blinded to MP and CP. In an additional 20 matched patients, in vivo CP, airway sealing pressure, and MP was measured at four different cuff locations (corresponding to the anterior, lateral, and posterior pharynx and the distal oropharynx) with increasing cuff volume. Results Blood vessel caliber and mucosal color was normal in all patients when the mean mucosal pressure was 17 cm H2O. Blood vessel caliber was first reduced when the mean mucosal pressure was 34 cm H2O. There was a progressive incremental reduction in blood vessel caliber and mucosal color when the mean mucosal pressure increased from 34 to 80 cm H2O (P < or = 0.05). Complete blood vessel collapse and mucosal paling first occurred with the mean mucosal pressure was 73 cm H2O and was present in 90% of patients when the mean mucosal pressure was 80 cm H2O. Mean MP was always higher in the posterior pharynx compared with the other locations when the cuff volume was 20 ml or greater (P < 0.001). In vivo CP is an excellent predictor of mucosal pressure. Mean (95% confidence interval [CI]) MP in the posterior pharynx was 35 (5-67) and 78 (50-109) cm H2O when the airway sealing pressure was 10 (6-16) and 17 (13-21) cm H2O respectively. Conclusion Pharyngeal mucosal perfusion is reduced progressively in the posterior pharynx when MP is increased from 34 to 80 cm H2O with the COPA. CP provides reliable information about MP and should be less than 120 cm H2O to prevent mucosal ischemia.

scholarly journals Sealing Mechanics Study of Laryngeal Mask Airways via 3D Modeling and Finite Element Analysis

2021 ◽  
Author(s):  
Hongxia Liao ◽  
Liqiang Chen ◽  
Junfeng Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cuff Pressure ◽  
3D Models ◽  
Laryngeal Mask ◽  
Comprehensive Understanding ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Sealing Mechanism ◽  
Mucosal Pressure

Abstract Background: Proper sealing of laryngeal mask airways (LMAs) is critical for airway management in clinical use. A good understanding of the LMA sealing mechanism provides a scientific foundation to improve the sealing of LMAs to reduce the incidence of adverse events. However, no existing methods provide a systematic study on the LMA sealing mechanics. Methods: Computer-aided 3D models are established to visualize LMA – pharynx interactions directly. The finite element analysis (FEA) is adopted to study the LMA sealing mechanics. Results: Two case studies are provided in the paper. The LMA is loaded with a low cuff pressure (CP) (9 mmHg) to investigate the cause of leaking in Case I, and with a high CP (45 mmHg) to detect the critical points of high mucosal pressure in Case II. The established 3D models provide initiative visualization of the sealing situations. The visualization results are verified by pressure distribution along the contacting surface generated from FEA as the quantitative study. Conclusions: Compared with the existing methods, the proposed method does not introduce additional cost, and can provide globe monitoring on the LMA and a comprehensive understanding of sealing mechanics in all areas. The findings on the sealing mechanism and corresponding suggestions for clinic use of LMAs and LMA design have also been presented in the paper.

Characteristics and risk factors of nasal mucosal pressure injury in intensive care units

2022 ◽  
Author(s):  
Ruiling Nan ◽  
Yujie Su ◽  
Juhong Pei ◽  
Haixia Chen ◽  
Li He ◽  
...  
Keyword(s):  
Risk Factors ◽  
Intensive Care ◽  
Intensive Care Units ◽  
Pressure Injury ◽  
Mucosal Pressure

Comparison of Mucosal Pressures Induced by Cuffs of Different Airway Devices

2006 ◽  
Vol 104 (5) ◽  
pp. 933-938 ◽  
Author(s):  
Herbert Ulrich-Pur ◽  
Franz Hrska ◽  
Peter Krafft ◽  
Helmut Friehs ◽  
Beatrix Wulkersdorfer ◽  
...  
Keyword(s):  
North America ◽  
Laryngeal Mask Airway ◽  
High Pressures ◽  
Laryngeal Mask ◽  
Esophageal Mucosa ◽  
Cuff Volume ◽  
Endotracheal Tubes ◽  
Tyco Healthcare ◽  
Intubating Laryngeal Mask Airway ◽  
Mucosal Pressure

Background High pressures exerted by balloons and cuffs of conventional endotracheal tubes, the Combitube (Tyco Healthcare Nellcor Mallinckrodt, Pleasanton, CA), the EasyTube (Teleflex Ruesch, Kernen, Germany), the Laryngeal Mask Airway (LMA North America, San Diego, CA), the Intubating Laryngeal Mask Airway (Fastrach; LMA North America), the ProSeal (LMA North America), and the Laryngeal Tube (LT; VBM Medizintechnik, Sulz, Germany) may traumatize the pharyngeal mucosa. The aim of this study was to compare pressures exerted on the pharyngeal, tracheal, and esophageal mucosa by different devices designed for securing the patient's airways. Methods Nineteen fresh cadavers were included. To measure mucosal pressures, microchip sensors were fixed on the anterior, lateral, and posterior surfaces of the proximal balloon and the distal cuff of the investigated devices. Depending on the respective airway device, the cuff volume was increased in 10-ml increments at the proximal balloon starting from 0 to a maximum of 100 ml, and in 2-ml increments at the distal cuff starting from 0 up to 12 ml. Results Tracheal mucosal pressures were significantly higher using the Combitube compared with the endotracheal tube and the EasyTube. Maximal esophageal pressures were significantly higher using the EasyTube compared with the Combitube. Using cuff volumes according to the manufacturers' guidelines, we found the highest pharyngeal pressures with the Intubating Laryngeal Mask Airway versus all other devices. At maximal volumes, the Laryngeal Mask Airway, the Intubating Laryngeal Mask Airway, and the ProSeal induced significantly higher pharyngeal pressures compared with all other devices. Using a pharyngeal cuff volume of 40 ml, the Intubating Laryngeal Mask Airway followed by the Laryngeal Mask Airway exerted significantly higher pressures compared with the other devices. Conclusions Although some devices exhibit a somewhat higher mucosal pressure when compared with others, the authors believe that the observed differences of the cuff pressures do not suggest a clinically relevant danger, because the investigated devices, except the endotracheal tubes, are not intended for prolonged use.

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