Assessing the accuracy of ultrasound measurements of tracheal diameter: an in vitro experimental study

Background Recent studies indicate that ultrasound can detect changes in tracheal diameter during endotracheal tube (ETT) cuff inflation. We sought to assess the accuracy of ultrasound measurement of tracheal diameter, and to determine the relationship between tracheal wall pressure (TWP), cuff inflation volume (CIV), and the degree of tracheal deformation. Methods Our study comprised two parts: the first included 45 porcine tracheas, the second 41 porcine tracheas. Each trachea was intubated with a cuffed ETT, which was connected to an injector and the manometer via a three-way tap. The cuff was inflated and the cuff pressure recorded before and after intubation. The tracheal diameter was measured using ultrasound. This included three separate measurements: outer transverse diameter (OTD), internal transverse diameter (ITD), and anterior tracheal wall thicknesses (ATWT). A precision electronic Vernier caliper was also used to measure tracheal diameter. We calculated TWP and the percentage change of tracheal diameter. The Bland–Altman method, linear regression, and locally weighted regression (LOESS) were used to analyze the data. Results There were strong correlation and agreement for OTD (r = 0.97, P < 0.001) and ITD (r = 0.90, P < 0.001) as measured by ultrasound and by precision electronic Vernier caliper, but a poor correlation for ATWT (r = 0.58, P < 0.001). There was a strong correlation between the percentage change of OTD (OTD%, r = 0.75, P < 0.001) and CIV, the percentage change of ITD (ITD%, r = 0.77, P < 0.001) and CIV, TWP (r = 0.75, P < 0.001) and CIV. And a strong correlation was also found between TWP and OTD% (r = 0.84, P < 0.001), TWP and ITD% (r = 0.84, P < 0.001). Conclusions Use of ultrasound to measure OTD and ITD is accurate, but is less accurate for ATWT. There is a close correlation between OTD%, ITD%, CIV and TWP.

Multidisciplinary approach to surgical treatment and rehabilitation of patients with defects of the anterior tracheal wall

The objective was to improve the results of treatment of patients with persistent defects of the anterior tracheal wall and soft tissues of the neck.Methods and materials. 220 patients with tracheal cicatrical stenosis were treated, of which 120 patients had defects of the anterior tracheal wall of various sizes. In 70% of cases, PCT was postintubation/posttracheostomy. Men predominated – 89 (74.2 %), women – 31 (25.8 %). After a routine examination, including endoscopic examination, MSCT of the chest with the capture of the cervical region, and general clinical diagnostic methods, all patients underwent surgical treatment.Results. According to the nature of the elimination of the defect of the anterior tracheal wall, patients were divided into several groups. Both local plastic surgery and the elimination of the tracheal defect with the use of microsurgical techniques were used. Circular resection of the trachea with the elimination of the defect was performed in 5 cases. In 2 cases, in the presence of a large persistent defect of more than 6 cm in size, a composite pre-fabricated deltopectoral skin-fascial-cartilage flap was used.Conclusion. The choice of a method for eliminating a persistent open defect of the anterior tracheal wall is determined individually in each case, it depends on its size, the depth of the airway lumen, and the condition of the surrounding tissues. The use of displaced skin-fascial flaps on the vascular pedicle for closing the tracheal defect allows to restore the mucous membrane of the tracheal defect area without using the surrounding scar tissue and close the defect with a second flap without straining the edges of the wound.

Cytokine regulation of inflammatory processes in respiratory organs of rats exposed to the combined inhalation of chemicals in low concentrations

Introduction. Morphological studies of animals (trachea, bronchi, lungs) exposed to the combined inhalation of chemicals in low concentrations showed the progression of structural changes, indicating the activation of inflammation and fibrosis in the lungs. The role of cytokine markers in developing inflammatory and fibrotic processes and remodeling lung tissue has been studied. Materials and methods. Male rats (180-200 g) were exposed to a mixture of chemicals (acetone, acetaldehyde, benzene) in low concentrations of 0.7-1.5; 0.9-1.4; 0.2-0.4 (mg/m3), respectively. The concentrations of IL-6, IL-10, IL-1b, IL-4, TGFβ1, TNFα cytokines (pg/ml) have been measured in the lung homogenate by enzyme-linked immunosorbent assay (ELISA). Microscopic anatomy of the lungs, tracheal wall, bronchi has been studied on the 30th day of exposure and the 15th and 90th days of the recovery period. Results. An increase in interleukin-4 and transforming growth factor TGFβ1 in the homogenate of the lung tissue was shown. An increase in lymphatic follicles, the number of lymphocytes, neutrophils, macrophages, and focal accumulations of eosinophils has been observed in the tracheal wall. In lymphoid infiltrates of the lung tissue - eosinophils, macrophages, and plasmocytes. Accumulation of eosinophilic exudate has been observed in some alveoli. The 90th day of the recovery period is characterized by a significant increase of TGFβ1 in the lung tissue, indicating fibrosis, as evidenced by the rise in the number of fibroblasts between the alveoli in the atelectasis zones of lungs. Conclusion. The chronic combined exposure to the mixture of chemicals in low concentrations is accompanied by a pro-inflammatory process in the lungs with the type II hypersensitivity and increasing IL-4 and TGFβ1 (a key mediator of profibrotic activity).

Management of the Embedded Tracheoesophageal Prosthesis: Retrograde Removal and Replacement

Objective: To describe the retrograde removal of a tracheoesophageal (TE) prosthesis embedded in the common wall between the trachea and esophagus with preservation of the original tracheoesophageal puncture (TEP) tract with subsequent placement of new tracheoesophageal prosthesis for voice restoration. Methods: The Blom-Singer TEP Set (InHealth Technologies, Carpinteria, CA) was used to facilitate this procedure. The coated wire leader cable was threaded through the small opening in the posterior tracheal wall and into the lumen of the old TE prosthesis. The wire was pulled through the mouth in retrograde fashion - bringing the old TE prosthesis out with it and dilating the existing TEP tract. A new prosthesis was then placed over the end of the wire and returned through the stoma, delivering the prosthesis through the TE tract and into the stoma. Results: Safe, voice restoration with avoidance of need for multiple procedures. Conclusion: Removal of an embedded prosthesis and simultaneous replacement of a new prosthesis was safely and efficiently achieved using a retrograde technique which maintained the patency of the prior TE tract and restored voice.

Complete resolution of diffuse inflammatory tracheal stenosis in a dog

A four-year-old female entire Weimaraner, recently diagnosed with epilepsy, was referred with a three-week history of coughing and lethargy. The dog had been diagnosed with aspiration pneumonia on thoracic radiographs, but the cough continued despite antibiotic therapy and an apparent improvement in the radiographic lung changes. CT of the thorax revealed a diffuse and severe nodular thickening of the tracheal wall. Tracheoscopy showed a thickened and irregular mucosa with multiple nodules causing segmental stenosis of the trachea. Histopathology of the nodular tracheal mucosa demonstrated severe, multifocal to diffuse neutrophilic inflammation. Once infectious and neoplastic causes were excluded, the dog was diagnosed with an inflammatory tracheitis of unknown aetiology. A tapering course of glucocorticoids was prescribed, which led to a complete clinical and endoscopic resolution of the coughing and tracheal lesions, respectively.

Difficult extubation with silicone endotracheal tubes in three dogs

Three dogs were anaesthetised for various procedures. Endotracheal intubation was achieved with cuffed silicone tubes. No difficulty was reported during the intubation in two out of the three cases, whereas in one case the tube could only be advanced a few centimetres past the glottis. Before extubation, the cuff was deflated in all cases, but the tubes could not be withdrawn past the point where the cuff was positioned within the arytenoids. Endoscopy was performed in two of the three cases and revealed no visible causes of movement hindrance. Computed tomography (CT) previously performed in one of the cases revealed that the outer surface of the tube was in contact with the tracheal wall. In all cases, the tubes could eventually be removed with lubrication and movement. These cases suggest that large silicone endotracheal tubes relative to the airway diameter may result in difficult extubation, and care should be taken with tube size selection.