The Influence of Cuff Volume and Anatomic Location on Pharyngeal, Esophageal, and Tracheal Mucosal Pressures with the Esophageal Tracheal Combitube

2002 ◽  
Vol 96 (5) ◽  
pp. 1074-1077 ◽  
Author(s):  
Christian Keller ◽  
Joseph Brimacombe ◽  
Micheal Boehler ◽  
Alexander Loeckinger ◽  
Friedrich Puehringer
Keyword(s):  
Perfusion Pressure ◽  
Topical Anesthesia ◽  
Cuff Volume ◽  
Anatomic Location ◽  
Mucosal Perfusion ◽  
Mucosal Pressure

Background The authors determined the influence of cuff volume and anatomic location on pharyngeal, esophageal, and tracheal mucosal pressures for the esophageal tracheal combitube. Methods Twenty fresh cadavers were studied. Microchip sensors were attached to the anterior, lateral, and posterior surfaces of the distal and proximal cuffs of the small adult esophageal tracheal combitube. Mucosal pressure for the proximal cuff in the pharynx was measured at 0- to 100-ml cuff volume in 10-ml increments, and for the distal cuff in the esophagus and trachea were measured at 0- to 20-ml cuff volume in 2-ml increments. The proximal cuff volume to form an oropharyngeal seal of 30 cm H2O was determined. In addition, mucosal pressures for the proximal cuff in the pharynx were measured in four awake volunteers with topical anesthesia. Results There was an increase in mucosal pressure in the trachea, esophagus, and pharynx at all cuff locations with increasing volume (all: P < 0.001). Pharyngeal mucosal pressures were highest posteriorly (50-ml cuff volume: 99 +/- 62 cm H2O; 100-ml cuff volume: 255 +/- 161 cm H2O). Esophageal mucosal pressures were highest posteriorly (10-ml cuff volume: 108 +/- 55 cm H2O; 20-ml cuff volume: 269 +/- 133 cm H2O). Tracheal mucosal pressures were highest anteriorly (10-ml cuff volume: 98 +/- 53 cm H2O; 20-ml cuff volume: 236 +/- 139 cm H2O). The proximal cuff volume to obtain an oropharyngeal seal of 30 cm H2O was 47 +/- 12 ml. Pharyngeal mucosal pressures were similar for cadavers and awake volunteers. Conclusion We conclude that mucosal pressures for the esophageal tracheal combitube increase with cuff volume, are highest where the cuff is adjacent to rigid anatomic structures, and potentially exceed mucosal perfusion pressure even when cuff volumes are limited to achieving an oropharyngeal seal of 30 cm H2O.

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.

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.

Pharyngeal Mucosal Pressures, Airway Sealing Pressures, and Fiberoptic Position with the Intubating versus the Standard Laryngeal Mask Airway 

1999 ◽  
Vol 90 (4) ◽  
pp. 1001-1006 ◽  
Author(s):  
Christian Keller ◽  
Joseph Brimacombe
Keyword(s):  
Laryngeal Mask Airway ◽  
Airway Management ◽  
Perfusion Pressure ◽  
Laryngeal Mask ◽  
Capillary Perfusion ◽  
Cuff Volume ◽  
Pyriform Fossa ◽  
Posterior Pharynx ◽  
Effective Seal ◽  
To Receive

Background The tube of the intubating laryngeal mask (ILM) is more rigid than the standard laryngeal mask airway (LMA), and the authors have tested the hypothesis that pharyngeal mucosal pressures, airway sealing pressures, and fiberoptic position are different when the two devices are compared. Methods Twenty anesthetized, paralyzed adults were randomly allocated to receive either the LMA or ILM for airway management. Microchip sensors were attached to the size 5 LMA or ILM at locations corresponding to the pyriform fossa, hypopharynx, base of tongue, posterior pharynx, and distal and proximal oropharynx. Mucosal pressures, airway sealing pressures, and fiberoptic positioning were recorded during inflation of the cuff from 0 to 40 ml in 10-ml increments. Results Airway sealing pressures were higher for the ILM (30 vs. 23 cm H2O), but epiglottic downfolding was more common (56% vs. 26%). Pharyngeal mucosal pressures were much higher for the ILM at five of six locations. Mean mucosal pressures in the distal oropharynx for the ILM were always greater than 157 cm H2O, regardless of cuff volume. There was no correlation between mucosal pressures and airway sealing pressures at any location for the LMA, but there was a correlation at three of six locations for the ILM. Conclusions The ILM provides a more effective seal than the LMA, but pharyngeal mucosal pressures are higher and always exceed capillary perfusion pressure. The ILM is unsuitable for use as a routine airway and should be removed after its use as an airway intubator.

Microvascular features that suggest effectors of blood-flow regulation in the brain: Evidence by SEM of corrosion casts of intracerebral vessels

1990 ◽  
Vol 48 (3) ◽  
pp. 274-275
Author(s):  
Enrico D.F. Motti ◽  
Hans-Georg Imhof ◽  
Gazi M. Yasargil
Keyword(s):  
Blood Flow ◽  
Perfusion Pressure ◽  
Corrosion Casts ◽  
Cerebral Microcirculation ◽  
Pial Arteries ◽  
Random Occurrence ◽  
Brain Arteries ◽  
Homogeneous Network ◽  
The Brain

Physiologists have devoted most attention in the cerebrovascular tree to the arterial side of the circulation which has been subdivided in three levels: 1) major brain arteries which keep microcirculation constant despite changes in perfusion pressure; 2) pial arteries supposed to be effectors regulating microcirculation; 3) intracerebral arteries supposed to be deprived of active cerebral blood flow regulating devices.The morphological search for microvascular effectors in the cerebrovascular bed has been elusive. The opaque substance of the brain confines in vivo investigation to the superficial pial arteries. Most morphologists had to limit their observation to the random occurrence of a favorable site in the practically two-dimensional thickness of diaphanized histological sections. It is then not surprising most investigators of the cerebral microcirculation refer to an homogeneous network of microvessels interposed between arterioles and venules.We have taken advantage of the excellent depth of focus afforded by the scanning electron microscope (SEM) to investigate corrosion casts obtained injecting a range of experimental animals with a modified Batson's acrylic mixture.

Transcranial Doppler ultrasonography in raised intra-cranial pressure and in intracranial circulatory arrest

1988 ◽  
Vol 68 (5) ◽  
pp. 745-751 ◽  
Author(s):  
Werner Hassler ◽  
Helmuth Steinmetz ◽  
Jan Gawlowski
Keyword(s):  
Intracranial Pressure ◽  
Brain Death ◽  
Intracranial Hypertension ◽  
Cerebral Perfusion Pressure ◽  
Transcranial Doppler ◽  
Cerebral Perfusion ◽  
Doppler Ultrasonography ◽  
Perfusion Pressure ◽  
Circulatory Arrest ◽  
Transcranial Doppler Ultrasonography

✓ Transcranial Doppler ultrasonography was used to monitor 71 patients suffering from intracranial hypertension with subsequent brain death. Among these, 29 patients were also assessed for systemic arterial pressure and epidural intracranial pressure, so that a correlation between cerebral perfusion pressure and the Doppler ultrasonography waveforms could be established. Four-vessel angiography was also performed in 33 patients after clinical brain death. With increasing intracranial pressure, the transcranial Doppler ultrasonography waveforms exhibited different characteristic high-resistance profiles with first low, then zero, and then reversed diastolic flow velocities, depending on the relationship between intracranial pressure and blood pressure (that is, cerebral perfusion pressure). This study shows that transcranial. Doppler ultrasonography may be used to assess the degree of intracranial hypertension. This technique further provides a practicable, noninvasive bedside monitor of therapeutic measures.

Sign in / Sign up

Export Citation Format

Share Document