UNASSIGNED: Leakage of orogastric secretions past the cuff of a tracheal tube is a contributory factor in ventilator-associated pneumonia. Current bench test methods specified in the International Standard for Anaesthetic and Respiratory Equipment (EN ISO 5361:2023) to test cuff leakage involve using a glass or plastic rigid cylinder model of the trachea. There is a need for more realistic models to inform cuff leakage.
UNASSIGNED: We used human computerised tomography data and additive manufacturing (3D printing), combined with casting techniques to fabricate a bio-inspired synthetic tracheal model with analogous tissue characteristics. We conducted cuff leakage tests according to EN ISO 5361:2023 and compared results for high-volume low-pressure polyvinyl chloride and polyurethane cuffs between the rigid cylinder trachea with our bio-inspired model.
UNASSIGNED: The tracheal model demonstrated close agreement with published tracheal tissue hardness for cartilaginous and membranous soft tissues. For high-volume low-pressure polyvinyl chloride cuffs the leakage rate was >50% lower in the bio-inspired tracheal model compared with the rigid cylinder model (151 [8] vs 261 [11] ml h-1). For high-volume low-pressure polyurethane cuffs, much lower leakage rates were observed than polyvinyl chloride cuffs in both models with leakage rates higher for the bio-inspired trachea model (0.1 [0.2] vs 0 [0] ml h-1).
UNASSIGNED: A reproducible tracheal model that incorporates the mechanical properties of the human trachea can be manufactured from segmented CT images and additive manufactured moulds, providing a useful tool to inform future cuff development, leakage testing for industrial applications, and clinical decision-making. There are differences between cuff leakage rates between the bio-inspired model and the rigid cylinder recommended in EN ISO 5361:2023. The bio-inspired model could lead to more accurate and realistic cuff leakage rate testing which would support manufacturers in refining their designs. Clinicians would then be able to choose better tracheal tubes based on the outcomes of this testing.

暂无摘要。

Incomplete sealing of tracheal diverticula by a tracheal tube cuff during positive-pressure ventilation causes barotrauma but the concrete possibility of incomplete sealing has not been indicated. We aimed to assess the possibility of incomplete sealing in a simulated situation of tracheal intubation for patients with tracheal diverticula with tube fixation where the tracheal tube\'s vocal cord guide overlaps with the patient\'s vocal cord.
We retrospectively assessed the characteristics of tracheal diverticula based on thoracic computed tomography data in our institution from January 2018 to July 2020. Then, we assessed the structural parameters of three single-lumen tracheal tubes (Parker Flex-Tip [Parker Medical, Bridgewater, CT, USA], Portex Soft Seal [ICU Medical, San Clemente, CA, USA], and Shiley TaperGuard [Medtronic, Dublin, Ireland]; 6.0-8.0 mm inner diameter size) and simulated the positional relationships between tracheal diverticula and the tracheal tube during tracheal intubation where the vocal cord guide overlaps with the patient\'s vocal cord. We assessed each tube product\'s possibility of incompletely sealing tracheal diverticula and the possibility of unintended bronchial intubation.
In 5,854 patients, the prevalence of tracheal diverticula was 5.7%. The mean (SD) length from the vocal cord to the distal end of the tracheal diverticula was 52.2 (12.8) mm. Tracheal tubes with length from the distal end of the tracheal cuff to the vocal cord guide of ≥ 70 mm had a low risk of incompletely sealing tracheal diverticula (< 5%) and length from the distal end of the tube to the vocal cord guide of ≤ 95 mm had a low risk of unintended bronchial intubation (< 5%). No products in this study satisfied both outcomes.
Tube fixation, where the vocal cord guide overlaps with the patient\'s vocal cord, is associated with risk of incompletely sealing of tracheal diverticula depending on the tube\'s manufacturer and tube\'s inner diameter size, although it was not a high risk. The use of small inner diameter sized tube relative to patient\'s body size is high risk of incomplete sealing of tracheal diverticula.
This trial was prospectively registered at University Hospital Medical Information Network (UMIN).
UMIN000043317 (URL: https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000048055 ).

The tracheal tube (TT) kink during the intraoperative period is commonly observed and is worrisome once the positioning is done during neurosurgical procedures. The complications related to tube kink are more in the prone position and the mechanism of this with the neck in flexion has not been explained anywhere. We have made an attempt to elucidate the probable mechanism of this TT kink by using SOLIDWORKS 2020 {3D Computer assisted design (CAD) design software} and the precautions that can be taken to prevent perioperative catastrophe by describing a case of a pediatric patient undergoing a neurosurgical procedure while in the prone position.

A tracheostomy tube (TT) is usually taken out in a well-planned and coordinated manner after the underlying condition that necessitated the procedure is resolved. The inadvertent removal or dislodgement of the TT from the stroma is known as accidental extubation or decannulation. This event may prove fatal in a stable patient. Like other respiratory procedures, tracheostomy with the long-term placement of tracheal tube comes with several risks, including scarring of the trachea, pneumothorax, tracheal rupture, and tracheoesophageal fistula. Other complications may include pneumomediastinum (PM) or the escape of air into the surrounding tissue. This may be attributed to several reasons, including mispositioning of the tracheal tube, barotrauma, or tracheal rupture. In some cases, PM presents with free air into cavities such as the thorax, peritoneum, or subcutaneous tissue. Although not fatal, it may require complex treatments such as ventilator management, high-flow oxygen, or, in some cases, surgical intervention. In this article, we describe a rare case of PM and generalized surgical emphysema due to mispositioning of the tracheal tube.

BACKGROUND: Trauma is one of the leading causes of death in the pediatric population. Bronchial rupture is rare, but there are potentially severe complications. Establishing and maintaining a patent airway is the key issue in patients with bronchial rupture. Here we describe an innovative method for maintaining a patent airway.
METHODS: A 3-year-old boy fell from the seventh floor. Oxygenation worsened rapidly with pulse oxygen saturation decreasing below 60%, as his heart rate dropped. Persistent pneumothorax was observed with insertion of the chest tube. Fiberoptic bronchoscopy was performed, which confirmed the diagnosis of bronchial rupture. A modified tracheal tube was inserted under the guidance of a fiberoptic bronchoscope. Pulse oxygen saturation improved from 60% to 90%. Twelve days after admission, right upper lobectomy was performed using bronchial stump suture by video-assisted thoracic surgery without complications. A follow-up chest radiograph showed good recovery. The child was discharged from hospital three months after admission.
CONCLUSIONS: A modified tracheal tube could be selected to ensure a patent airway and adequate ventilation in patients with bronchial rupture.

OBJECTIVE: Choosing the right tracheal tube for the right patient is a daily preoccupation for intensivists and emergency physicians. Tracheal tubes can generate severe complications, which are chiefly due to the pressures applied by the tube to the trachea. We designed a bench study to assess the frequency of pressure levels likely to cause tracheal injury.
METHODS: We tested the pressure applied on the trachea by 17 tube models of a given size range. To this end, we added a pressure sensor to the posterior tracheal wall of a standardized manikin.
RESULTS: Only 2 of the 17 tubes generated pressures under the threshold likely to induce tracheal injury (30 mmHg/3.99 kPa). The force exerted on the posterior wall of the trachea varied widely across tube models.
CONCLUSIONS: Most models of tracheal tubes resulted in forces applied to the trachea that are usually considered capable of causing tracheal tissue injury.
METHODS: Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence: How common is the problem?: step 1; Is this diagnostic or monitoring test accurate? (Diagnosis) step 5; What will happen if we do not add a therapy? (Prognosis) n/a; Does this intervention help? (Treatment Benefits) step 5; What are the COMMON harms?(Treatment Harms) step 5; What are the RARE harms? (Treatment Harms) step 5; Is this (early detection) test worthwhile? (Screening) step 5.

Flexible bronchoscope-guided tracheal intubation through supraglottic airway devices (SGAs) is a well-established element of difficult intubation algorithms. Success can be limited by dimensional incompatibilities between tracheal tubes (TTs) and SGAs.
In this in vitro study, we tested the feasibility of TT passage through SGAs, removal of SGAs over TTs, and the ability to guide the flexible bronchoscope with 13 TT brands (internal diameter, 6.5-8.0 mm) and ten different SGAs (#4 and #5) in an intubation mannequin.
We tested 1,040 combinations of SGAs and TTs. Tracheal tube passage failed in 155 (30%) combinations of the five tested first-generation SGAs (117 [46%] with SGA #4, 38 [15%] with SGA #5) and in three (0.6%) combinations of the five tested second-generation SGAs (two [0.8%] with SGA #4 and one [0.4%] with SGA #5). The reason for failed passage of a TT through a first-generation SGA consistently was a too-narrow SGA connector. Removal of the SGA over the TT in the 882 remaining combinations was impossible for all sizes of reinforced TTs, except the Parker Reinforced TT, and was possible for all non-reinforced TTs. Only one combination with SGA #4 and 84 combinations with SGA #5 were not ideal to adequately guide the flexible bronchoscope.
Clinically relevant combinations of adult-size TTs and SGAs can be incompatible, rendering flexible bronchoscope-guided tracheal intubation through an SGA impossible. Additional limitations exist regarding removal of the SGA and maneuverability of the flexible bronchoscope.
RéSUMé: CONTEXTE: L’intubation endotrachéale guidée par bronchoscope flexible via un dispositif supraglottique (DSG) est un élément établi des algorithmes utilisés pour les intubations difficiles. La réussite de l’intubation peut être limitée par des incompatibilités dimensionnelles entre les tubes endotrachéaux (TET) et les DSG. MéTHODE: Dans cette étude in vitro, nous avons testé la faisabilité de faire passer un TET par un DSG, le retrait du DSG par-dessus le TET et la possibilité de guider un bronchoscope flexible avec 13 marques de TET (diamètre interne, 6,5-8,0 mm) et dix DSG différents (#4 et #5) sur un mannequin d’intubation. RéSULTATS: Nous avons testé 1040 combinaisons de DSG et de TET. Le passage du tube endotrachéal a échoué dans 155 (30 %) combinaisons avec les cinq DSG de première génération testés (117 [46 %] avec DSG #4, 38 [15 %] avec DSG #5) et dans trois (0,6 %) combinaisons avec les cinq DSG de deuxième génération testés (deux [0,8 %] avec DSG #4 et une [0,4 %] avec DSG #5). La raison de l’échec du passage d’un TET à travers un DSG de première génération était systématiquement liée à un connecteur de DSG trop étroit. Dans les 882 combinaisons restantes, le retrait du DSG par-dessus le TET s’est avéré impossible avec toutes les tailles de TET armés, à l’exception du TET armé Parker, et était possible avec tous les TET non armés. Une seule combinaison avec le DSG #4 et 84 combinaisons avec le DSG #5 n’étaient pas idéales pour guider le bronchoscope flexible de manière adéquate. CONCLUSION: Les combinaisons cliniquement pertinentes de TET et de DSG de tailles adultes peuvent être incompatibles, rendant impossible l’intubation endotrachéale guidée par bronchoscope flexible via un DSG. D’autres limites existent en ce qui concerne le retrait du DSG et la maniabilité du bronchoscope flexible.

OBJECTIVE: To assess safety and efficacy of a novel intubation laryngeal mask airway (ILMA) during the recovery period following supratentorial tumour surgery.
METHODS: Patients who underwent supratentorial tumour surgery at our centre from January 2012 to December 2016 were eligible for this prospective randomised, parallel group study. We developed a novel ILMA using closely fitting laryngeal masks (No. 4/5) with 7.0/7.5 mm endotracheal tubes (ETT) plus screw fixators and anti-pollution sleeves.
RESULTS: In total, 100 patients were intubated with the novel ILMA and 100 the ETT. There were no differences between groups in haemodynamic variables, oxygen saturation, exhaled CO2, or bispectral index all recorded during the 72-hour recovery period. However, there were significantly fewer incidences of coughing, less fluid drainage and lower haemoglobin levels in surgical fluid in the ILMA group compared with the ETT group.
CONCLUSIONS: Our novel ILMA device was associated with reduced coughing, fluid drainage and blood in surgical drain during the recovery period following supratentorial tumour surgery.

BACKGROUND: We examined the association between emergent postoperative tracheal intubation and the use of supraglottic airway devices (SGAs) vs tracheal tubes.
METHODS: We included data from adult noncardiac surgical cases under general anaesthesia between 2008 and 2018. We only included cases (n=59 991) in which both airways were deemed to be feasible options. Multivariable logistic regression, instrumental variable analysis, propensity matching, and mediation analysis were used.
RESULTS: Use of a tracheal tube was associated with a higher risk of emergent postoperative intubation (adjusted absolute risk difference [ARD]=0.80%; 95% confidence interval (CI), 0.64-0.97; P<0.001), and a higher risk of post-extubation hypoxaemia (ARD=3.9%; 95% CI, 3.4-4.4; P<0.001). The effect was modified by the use of non-depolarising neuromuscular blocking agents (NMBAs); mediation analyses revealed that 28.9% (95% CI, 14.4-43.4%; P<0.001) of the main effect was attributable to NMBA. Airway management modified the association of NMBA and risk of emergent postoperative intubation (Pinteraction=0.02). Patients managed with an SGA had higher odds of NMBA-associated reintubation compared to patients managed with a tracheal tube (adjusted odds ratio [aOR]=3.65, 95% CI, 1.99-6.67 vs aOR=1.68, 95% CI, 1.29-2.18 [P<0.001], respectively).
CONCLUSIONS: In patients undergoing procedures under general anaesthesia that could be managed with either SGA or tracheal tube, use of an SGA was associated with lower risk of emergent postoperative intubation. The effect can partly be explained by use of NMBAs. Use of NMBAs in patients with an SGA appears to increase the risk of emergent postoperative intubation.