Clearance of Mucus from Endotracheal Tubes during Intratracheal Pulmonary Ventilation

Background Intratracheal pulmonary ventilation (ITPV) is a form of tracheal gas insufflation in which all gas emerges in a cephalad direction from the tip of a reverse-thrust catheter positioned within an endotracheal tube. In vitro experiments have shown that this rapid gas flow, with 5 ml/h of normal saline added to the gas flow, continuously removes tracheal secretions from within the endotracheal tube. The authors evaluated its effectiveness to remove mucus in long-term studies in sheep. Methods Fourteen healthy sheep were tracheally intubated and ventilated for 3 days with ITPV or with volume-controlled ventilation. Measurements were made of the total amount of secretions within the endotracheal tubes (weight gain), the protein content within the endotracheal tubes, and the increase in resistance to constant air flow. The structure of the airways was examined grossly and histologically. Three additional sheep were ventilated for 24 h with ITPV, and Evans Blue dye was added to the saline to assess the distribution of the infused saline. Results There was significantly less mucus in endotracheal tubes of sheep ventilated with ITPV than with conventional ventilation, as shown by minimal weight gain (0.70 +/- 0.14 g vs. 2.44 +/- 0.81 g; P < 0.001), lower protein content (14.09 +/- 10.79 mg vs. 294.99 +/- 153.06 mg; P < 0.001), and lower resistance to constant air flow (6.15 +/- 0.54 cm H2O x 1(-1) x s(-1) vs. 15.34 +/- 5.28 cm H2O x 1(-1) x s(-1); P < 0.001). Results of gross and histological examinations of the tracheas of animals in both groups were similar, and the tracheas were well preserved. More than 95% of the instilled saline was recovered during ITPV. Only traces of Evans Blue dye were found near the tip of the endotracheal tubes. Conclusion Intratracheal pulmonary ventilation makes it possible to keep the endotracheal tubes of sheep ventilated for 3 days free of mucus without suctioning.

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Sustained laryngeal transient receptor potential vanilloid 1 activation inhibits mechanically induced swallowing in anesthetized rats

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00082.2020 ◽

2020 ◽

Vol 319 (3) ◽

pp. G412-G419

Author(s):

Midori Yoshihara ◽

Takanori Tsujimura ◽

Taku Suzuki ◽

Kouta Nagoya ◽

Naru Shiraishi ◽

...

Keyword(s):

Vascular Permeability ◽

Evans Blue ◽

Transient Receptor Potential ◽

Air Flow ◽

Receptor Potential ◽

Blue Dye ◽

Transient Receptor Potential Vanilloid ◽

Evans Blue Dye ◽

Capsaicin Application ◽

Transient Receptor

Although a transient receptor potential vanilloid 1 (TRPV1) inhibitor or TRPV1-expressed neuronal inhibitor significantly inhibited HCl/capsaicin-evoked swallowing, air flow-induced swallowing was not affected. The number of air flow-induced swallows was significantly reduced within 60 min of TRPV1 activation. Evans blue dye concentration in the larynx increased 60 min after capsaicin application. TPRV1 activation not only desensitizes TRPV1 but also inactivates mechanoreceptors caused by increases in vascular permeability and edema.

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Evans Blue Dye as an in vivo marker of myofibre damage: optimising parameters for detecting initial myofibre membrane permeability

Journal of Anatomy ◽

10.1046/j.0021-8782.2001.00008.x ◽

2002 ◽

Vol 200 (1) ◽

pp. 69-79 ◽

Cited By ~ 190

Author(s):

P. W. Hamer ◽

J. M. McGeachie ◽

M. J. Davies ◽

M. D. Grounds

Keyword(s):

Membrane Permeability ◽

Evans Blue ◽

Blue Dye ◽

Evans Blue Dye

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Regional Deposition of Inhaled Evans Blue Dye in Mechanically Ventilated Rabbits with Air or Helium Oxygen Mixture

Experimental Lung Research ◽

10.3109/01902149809099580 ◽

1998 ◽

Vol 24 (2) ◽

pp. 159-172 ◽

Cited By ~ 4

Author(s):

Magnus Svartengren ◽

Patrik Skogward ◽

Ola Nerbrink ◽

Magnus Dahlbäck

Keyword(s):

Evans Blue ◽

Oxygen Mixture ◽

Blue Dye ◽

Mechanically Ventilated ◽

Evans Blue Dye ◽

Regional Deposition

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Acoustic enhanced Evans blue dye perfusion in neurological tissues

10.1121/1.2890703 ◽

2007 ◽

Cited By ~ 1

Author(s):

George K. Lewis Jr. ◽

Willam L. Olbricht ◽

George Lewis

Keyword(s):

Evans Blue ◽

Blue Dye ◽

Evans Blue Dye

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Flow of edema fluid into pulmonary airways

Journal of Applied Physiology ◽

10.1152/jappl.1983.55.4.1262 ◽

1983 ◽

Vol 55 (4) ◽

pp. 1262-1268 ◽

Cited By ~ 5

Author(s):

G. R. Mason ◽

R. M. Effros

Keyword(s):

Evans Blue ◽

Left Atrial ◽

Blue Dye ◽

Edema Formation ◽

Evans Blue Dye ◽

Colloid Particles ◽

Edema Fluid ◽

Pulmonary Airways ◽

99Mtc Sulfur Colloid

An in situ rabbit preparation was used to characterize the manner in which edema fluid enters the airways when left atrial pressures are elevated. The airways were initially filled with fluid to minimize retrograde flow of edema fluid into the alveoli. The airway solution contained 125I-albumin and in some studies [14C]sucrose, and the lungs were perfused with a comparable solution which contained albumin labeled with Evans blue dye and 99mTc-diethylenetriaminepentaacetate (DTPA) or 99mTc-sulfur-colloid particles (0.4-1.7 micron diam). After 30 min of perfusion, fluid was pumped from the airways into serial tubes. When left atrial pressures were low, there was very little transfer of labels detectable between the airway and perfusate solutions. However when left atrial pressures were increased to either 15 or 22 cmH2O, fluid entered the airways containing approximately the same concentrations of Evans blue dye and 99mTc-DTPA as those present in the perfusate. In contrast, the concentration of colloid particles averaged less than 5% perfusate concentrations, indicating that the fluid had not escaped through a tear in the barriers separating the vascular and airway compartments. Concentrations of the perfusate fluid and indicators were highest in the initial samples pumped from the airways. These observations suggest that some of the fluid entering the airways may be derived from peribronchial cuffs or that there are marked regional differences in edema formation from alveoli.

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A modified bioassay for heat-stable Escherichia coli enterotoxin

Canadian Journal of Microbiology ◽

10.1139/m77-049 ◽

1977 ◽

Vol 23 (3) ◽

pp. 331-336 ◽

Cited By ~ 8

Author(s):

S. Stavric ◽

D. Jeffrey

Keyword(s):

Escherichia Coli ◽

Body Weight ◽

Incubation Time ◽

Evans Blue ◽

Room Temperature ◽

Blue Dye ◽

Evans Blue Dye ◽

Heat Stable ◽

Stomach Distention ◽

Time Required

Infant mice were injected orally with preparations containing Escherichia coli heat-stable enterotoxin (ST) and Evans blue dye, and incubated at 22 °C. With enterotoxin-positive samples, the stomach was distended and contained essentially all of the dye. With enterotoxin-negative samples, the stomach remained normal in size and the dye passed freely into the intestines. The time required to obtain the maximum ratio of gut weight to body weight varied from 30 to 90 min and was dependent upon the concentration of enterotoxin. Heat-labile enterotoxin (LT) had no effect during this period.Based on these findings, the mouse incubation time was reduced from 4 h to 90 min, and the heating of test samples was retained only for confirmation of ST. The location of the dye and stomach distention served as an indicator of positive responses to ST. Incubation of the mice at room temperature (22 °C) was found satisfactory.

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A Study of the Pathogenesis and Prevention of Central Pontine Myelinolysis in a Rat Model

Journal of International Medical Research ◽

10.1177/147323000603400305 ◽

2006 ◽

Vol 34 (3) ◽

pp. 264-271 ◽

Cited By ~ 6

Author(s):

Q-H Ke ◽

T-B Liang ◽

J Yu ◽

S-S Zheng

Keyword(s):

Hypertonic Saline ◽

Blood Brain Barrier ◽

Evans Blue ◽

Central Pontine Myelinolysis ◽

Brain Barrier ◽

Blue Dye ◽

Evans Blue Dye ◽

Pontine Myelinolysis ◽

Demyelinating Lesions ◽

Central Pontine

The development of central pontine myelinolysis was studied in rats. Severe hyponatraemia was induced using vasopressin tannate and 2.5% dextrose in water and then rapidly corrected with hypertonic saline alone, hypertonic saline and dexamethasone simultaneously, or hypertonic saline plus dexamethasone 24 h later. The permeability of the blood-brain barrier was evaluated using the extravasation of Evans blue dye and the expression of inducible nitric oxide synthase (iNOS) in the brain was examined using Western blot analysis. Histological sections were examined for demyelinating lesions. In rats receiving hypertonic saline alone, Evans blue dye content and expression of iNOS began to increase 6 and 3 h, respectively, after rapid correction of hyponatraemia and demyelinating lesions were seen. When dexamethasone was given simultaneously with hypertonic saline, these increases were inhibited and demyelinating lesions were absent. These effects were lost if dexamethasone injection was delayed. Disruption of the blood-brain barrier and increased iNOS expression may be involved in the pathogenesis of central pontine myelinolysis, and early treatment with dexamethasone may help prevent the development of central pontine myelinolysis.

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