Diameter Endotracheal Tube Research Articles

Consequences of NICU Intubations: Incidence, Identifications, and Interventions.

Prolonged intubation often leads to laryngeal injuries such as subglottic stenosis (SGS), especially in neonates with prematurity and congenital defects key for tissue healing. Recognizing at risk patients in the neonatal intensive care unit (NICU) is not well studied. The study's goals were to determine intubation risk factors, characterize laryngeal injuries, and calculate the incidence of intervention. Retrospective case review. Quaternary pediatric referral center. This retrospective study included all intubated patients in the NICU from April 1, 2020 to 2023. Electronic records were reviewed for demographics and intubation details. Patients were categorized to into intubation only or intervention groups, including direct laryngoscopy and bronchoscopy (DLB) and tracheostomy history. A total of 441 patients were identified with 94 (21%) neonates undergoing DLB. Characteristics impacting intervention included older gestational age, genetic syndromes, and congenital heart disease. Significant risk factors were older age at first intubation, recurrent intubation events, longer intubation duration, and larger endotracheal tube (ETT) diameter, but not birth weight or intubation attempts. Otolaryngology was more likely to intubate the intervention cohort. SGS overall incidence was 2.95% with balloon dilation in 6.4%. Two-thirds of neonates with DLB ultimately required tracheostomy, in which all variables remained significant risk factors except for gestational age. Older age at first intubation, more intubation events, longer intubation duration, and larger ETT increased risk for future DLB and tracheostomy but not birth weight or number of intubation attempts. Most NICU patients selected for DLB ultimately required further procedures.

Retromolar intubation for the general anesthesia of maxillofacial fracture patients

BackgroundEvaluate the possibility of retromolar intubation for general anesthesia in patients with maxillofacial fractures.MethodsThe medical records of 54 patients with maxillofacial fractures who visited the Oral and Maxillofacial Surgery Department of Nantong First People’s Hospital from January 2020 to August 2022 were collected. The retromolar areas of each patient were measured from the coronal CT images, and correlated with the patient’s age, sex, type of fracture (i.e., maxillary fracture, mandibular fracture, or complex fracture of multiple maxillofacial bones), and the presence of the third molar (verified from 3D CT). The dimensions of the retromolar areas were finally compared with the outer diameter (OD) of standard endotracheal tubes (ETTs), most importantly the size 7.5 ETT (OD 10.3 mm) for male and the size 7.0 ETT (OD 9.8 mm) for female.ResultsThe survey included 38 male and 16 female patients, with an average age of 44.1 and 54.3 years, respectively. The dimensions of the retromolar area (height × width) were as follows: male, (9.39 ± 1.77) mm × (12.08 ± 0.98) mm on the left and (9.81 ± 2.23) mm × (11.77 ± 1.08) mm on the right; female, (8.82 ± 1.53) mm × (10.51 ± 1.00) mm on the left and (9.73 ± 1.60) mm × (10.63 ± 1.58) mm on the right. The width was always larger than the OD of the routinely used ETT, but the height could be smaller by less than 1 mm. However, the oral mucosa can be compressed to allow the ETT to fit in the retromolar area.ConclusionsThe retromolar area provided appropriate space to place a reinforced ETT for patients with maxillofacial fractures needing general anesthesia that must not interfere with intermaxillary ligation. Retromolar intubation can help maxillofacial fracture surgeries that focus on occlusal restoration.

Nasotracheal intubation with the aid of nasopharyngeal airway

Introduction & objective: Oral and maxillofacial surgeries commonly require nasotracheal intubation (NTI) to overcome difficulty of work in the oropharyngeal space. Several variables affect intubation difficulty and complications and include tube type or design, topical vasoconstrictors, lubricating the endotracheal tube (ETT), selecting smaller diameter ETT, using urethral catheter to assist NTI, using some catheters etc. We aimed to explore the effectiveness of nasopharyngeal airway (NPA) as a factor facilitating the passage of ETT in the nasopharynx and diminishing trauma and bleeding during NTI. Methodology: One hundred-forty patients undergoing surgery in the oral and maxillofacial area were divided into groups of 70 each; NPA group, in which an NPA was used as an assist device, and non-NPA group with non-NPA use. Before intubation, the more patent nostril was identified, topical nasal vasoconstrictor was used, lubricant jelly applied and thermo softening of the ETT achieved. In NPA group, nasal cavity dilatation was done with an NPA before NTI. The ease of ETT passage and any nasopharyngeal bleeding were assessed by a scale of four grades. Results: About 95.71% patients had easy (grade 0 or 1) passage of ETT in the NPA group compared to 81.43% in the non-NPA group (P < 0.0001, P = 0.006), and the remaining grades also showing significant differences between groups. About 98.57% patients had grade 0 to 1 bleeding (no or traces of blood) in the NPA group, compared to 97.14% in the non-NPA group (P = 0.001) and the remaining grades also showed significant differences between the groups. NPA minimized difficulties in passage of the ETT and complications. Conclusion: Application of nasopharyngeal airway in patients undergoing nasotracheal intubation for general anesthesia proved to be effective in increasing nasal cavity space and minimizing difficulties faced in the passage of the endotracheal tube through the nasal passages and diminishing the resulting complications. Abbreviations: ETT- Endotracheal Tube; NPA- Nasopharyngeal Airway; NTI- Nasotracheal Intubation Keywords: Endotracheal Tube; Lubricating Gel; Maxillofacial; Nasopharyngeal Airway; Nasotracheal Intubation; Surgery, Oral; Surgery Citation: Abd Al-Qader BK, Abdulahad SA, Mohammad HM. Nasotracheal intubation with the aid of nasopharyngeal airway. Anaesth. pain intensive care 2024;28(1):50−54; DOI: 10.35975/apic.v28i1.2263 Received: July 09, 2023; Reviewed: December 10, 2023; Accepted: December 30, 2023

ANESTHESIA IN CAPTIVE GIANT PANDAS (AILUROPODA MELANOLEUCA) WITH MEDETOMIDINE-KETAMINE.

One male and one female giant panda (Ailuropoda melanoleuca) from a Belgian zoo were anesthetized on eight different occasions over a course of 4 yr for electro-ejaculation (n = 3) or artificial insemination (n = 5). Medetomidine (0.03-0.04 mg/kg) and ketamine (2.5-3 mg/kg) were administered by intramuscular remote injection. Animals gained sternal recumbency with the loss of response to external stimuli after 4.9 ± 1.6 min (mean ± SD). The trachea was intubated with a 14-mm-internal diameter endotracheal tube; anesthesia was maintained with isoflurane in oxygen adjusted according to the required depth of anesthesia with a small-animal circle system. Physiological variables (heart rate, respiratory rate, oxygenation, end tidal carbon dioxide partial pressure and non-invasive blood pressure) were measured and remained within an acceptable range throughout anesthesia. Atipamezole (0.17-0.25 mg/kg) was administered intramuscularly after anesthesia. Recoveries were rapid and uneventful. Medetomidine 0.03 mg/kg and ketamine 2.5 mg/kg IM appeared to be the preferred doses for giant pandas.

The Effect of the Ultrasonography Measurement Method and the Conventional Measurement Method Used in Endotracheal Tube Size Selection in the Pediatric Patient Group on Postextubation Complications and Patient Recovery.

In this study, we aimed to compare the cuffed intubation tube selected with the Cole formula and tracheal ultrasonography (USG) measurement method regarding postextubation complications in providing airway patency and determine its effects on patient recovery. Between 01 July 2022 and 30 June 2023, American Society of Anesthesiologists (ASA) risk group I-III, 4-6-year-old patients who underwent pediatric orthodontic surgery (multiple tooth extraction) were included in the study. Data of age, gender, weight, ASA risk group, history, Cole formula, USG measurement results used in the endotracheal tube (ETT) selection (one of the two whichever application was used), fasting time, intubation success, operation time, 30th-minute modified Aldrete recovery score (MASS), and postoperative complications due to intubation (within the first postoperative hour) were analyzed retrospectively. The patients were divided into two groups according to the method used by the anesthesiologists in selecting the ETT at the beginning of the operation. The group that used Cole formula management was named I, while the group that used the USG measurement method was called II. Intubation-related complication data of the patients in the first 1 hour postoperatively and MASS values at the 30th minute were compared between the groups. In this study, 52.5% of the cases were male (n=42), 47.5% were female (n=38), the mean age was 4.84±0.84 years, and the mean body weight was 22.56±7.58 kilogram. There was no statistically significant difference between the groups regarding age, gender, body weight, ASA score, operation time, and period without oral consumption. ETT diameter measurement values according to groups were 4.73±0.46 mm in Group I and 4.41±0.61 mm in Group II. Postoperative 30th-minute MASS values were median 7 in Group I and median 8 in Group II (p<.001). MASS values were significantly higher in the Group II patient group. Intubation-related complications (postoperative cough, stridor, laryngospasm, tachypnea, wheezing, dysphonia) were observed in Group I with a rate of 40% within the first postoperative hour, while complications were marked with a rate of 17.5% in Group II (p=0.026). Complications in group II were significantly lower. In the pediatric age group, especially under the age of 6, trachea measurement with USG and ETT selection is an effective, safe, and noninvasive method compared to other conventional methods. ETT size selection with USG accelerates postoperative patient recovery and reduces the risk of intubation-related complications. In addition, inflating the tube cuff under USG guidance can prevent cuff-related complications.

Unexpected Difficult Intubation caused by Undiagnosed Laryngeal Tuberculosis in a Patient Requiring Pericardiectomy for Tuberculosis Pericarditis: A Case Report

Airway management is a critical aspect of anesthesia, and difficulties in endotracheal intubation can lead to life threatening complications. While an anticipated difficult intubation can be managed with proper preparation and planning, unexpected difficult intubation can be a challenging situation even to skilled anesthesiologists. We experienced unexpected difficult intubation in a 66-year-old male patient with known tuberculosis pericarditis scheduled for elective pericardiectomy surgery. Multiple intubation attempts were made using various techniques, and successful intubation was achieved with a smaller diameter endotracheal tube. Surgery was uneventful and post-operative evaluation of the airway confirmed laryngeal tuberculosis. This case highlights the importance of vigilance in managing unexpected difficult intubation, especially in patients with a history of tuberculosis or immunosuppressive conditions. Prompt recognition of airway stenosis and appropriate interventions are crucial in securing the airway patency to minimize complications in patients with undiagnosed tuberculosis laryngitis.

The impact of the endotracheal intubation tube diameter on drug delivery during high-frequency oscillatory ventilation process

The impact of the endotracheal intubation tube diameter on drug delivery during high-frequency oscillatory ventilation process

Ultrasonography measurement of glottic transverse diameter and subglottic diameter to predict endotracheal tube size in children: a prospective cohort study

We aimed to determine the correlation between mid-glottic transverse diameter/subglottic diameter and outer diameter of endotracheal tube (ETT) by ultrasonography in children. Ninety-five patients aged 1–8 years who underwent general anesthesia were included. Ultrasonography of glottic/subglottic transverse diameter was performed by two investigators after patients were anesthetized and when the train of four showed ≤ 4. The subglottic diameter was measured at the mid cricoid cartilage. The mid-glottic transverse diameter was measured at the mid-point of true vocal fold triangle whereas the distance between arytenoids was considered as the glottic transverse diameter. Linear regression models and correlation coefficients (r) were used to determine the best formula of glottic/subglottic transverse diameter to predict the outer diameter of ETT. The predicted outer diameter of ETT formula for subglottic diameter, mid-glottic transverse diameter, and glottic transverse diameter were 5.7 + (subglotticmm/3) with an r of 0.45, 5.5 + (midglotticmm/2) with an r of 0.47, and 5.7 + (glotticmm/4) with an r of 0.46, respectively. The correlation between subglottic diameter and mid-glottic transverse diameter was 0.50. Subglottic/mid-glottic/glottic transverse diameter formulae had moderate correlations with the outer diameter of ETT. The glottic/mid-glottic transverse diameter can be used alternatively to predict the ETT size.Trial registration: Thai Clinical Trial Registry: TCTR20191022002 Registered 22/10/2019—Prospectively registered, https://www.thaiclinicaltrials.org/# TCTR20191022002.

Accuracy Comparison between Four Methods of Endotracheal Tube Diameter Estimation for Pediatric Patients

Abstract Background: Successful intubation with the correct endotracheal tube (ETT) size is more difficult to achieve in pediatric patients. Several estimation methods exist, including ultrasonography and several conventional methods, but it is unclear which would be the most accurate method. Thus, this study aimed to compare the accuracy between several ETT diameter estimation methods. Materials and Methods: This was an observational study with a cross-sectional design. The sample includes pediatric patients (0–6 years) at a tertiary hospital recruited from January 2022 to March 2022. Primary data evaluated included age, gender, height, weight, actual ETT size used in the procedure, and the estimation of ETT size obtained by four different methods: ultrasonography, little finger diameter, little fingernail width, and age-based formula. Primary analysis was linear regression test between estimated diameter and the actual ETT diameter used in the procedure, controlling for potential confounders. The accuracy of each ETT size estimation method was seen from the values of the B and R2 coefficients from the linear regression test results. Results: Ultrasonography was found as the most accurate method, with B and R2 coefficients of 0.963 and 0.991, respectively. Among conventional methods, the diameter of the little finger was the most accurate (B = 0.918, R2 = 0.772). The age-based formula method was found to be the least accurate (B = 0.797, R2 = 0.735). Conclusion: Linear regression tests confirmed that the ultrasonography was the estimation method with the highest accuracy. For healthcare facilities with limited resources, the estimation method with little finger diameter should be considered.

Difficult airway following inhalational burn injury in a child

Airway management in a burn victim poses special challenges for the anaesthesiologist not only during the acute phase but also after delayed consequences have set in resulting in difficulty in airway management. We report a 5-year-old boy who was admitted to the Department of Paediatrics with biphasic stridor 2 months following inhalational burn injury. He presented with complaints of difficulty in swallowing solid food, hoarseness of voice for the past 1 month and occasional difficulty in breathing for the past 10 days. Laryngoscopy using a #2 Macintosh blade revealed pharyngeal stenosis with grossly distorted airway anatomy. The patient was finally intubated after great difficulty with a 3.5 mm internal diameter endotracheal tube using a fibrescope.

Difficult Ventilation in a patient after Endotracheal Intubation: an Unusual Manufacturing Defect in E.T.T. Connecter

Summary: Airway resistance depends upon the diameter of endotracheal tube (E.T.T) and other respiratory organs. Actually resistance to flow through a tube increases up to sixteen times if diameter is reduced to half of the original size. Disposable E.T.T which are currently used in anaesthesia practice are made up of P.V.C with a connecter which is fitted on proximal end of endotracheal tube and proximal end of connector I attached with breathing circuit. Usually the internal diameter of connector should be equal to internal diameter of endotracheal tube.

Comparison of nostril sizes of newborn infants with outer diameter of endotracheal tubes

BackgroundRecommendations for endotracheal tube (ETT) size usually refer to the inner diameter (ID). Outer diameters (OD), however, vary greatly between manufacturers, which in some brands might cause difficulties in passing the ETT through the nostrils if choosing the nasal route for intubation. Even though the nostrils are dilatable by an ETT, it might be difficult to pass an ETT through the posterior naris (narrowest point of the nasal passage), if the OD is bigger than the nostrils. Therefore, nostril size may provide some guidance for the appropriate ETT size preventing unsuccessful intubation attempts. This study therefore compares nostril sizes of newborn infants with ODs of ETTs from several manufacturers.MethodsThis is a subgroup analysis of a prospective observational study, performed in a single tertiary perinatal centre in Germany. The diameter of the nostril of infants born between 34 and 41 weeks´ gestation was measured in 3D images using 3dMDvultus software and compared to the OD of ETT from five different manufacturers.ResultsComparisons of nostril sizes with ODs of different ETTs were made for 99 infants with a mean (SD) birthweight of 3058g (559) [range: 1850-4100g]. Mean (SD) nostril size was 5.3mm (0.6). The OD of the 3.5mm ETT of different manufacturers ranged from 4.8-5.3mm and was thus larger than the nostril size of 20-46% of late preterm or term infants.Some OD of a 3.0mm ETT were even bigger than the OD of a 3.5mm ETT (e.g. the 3.0mm ETT from Rüsch® has an OD of 5.0mm while the 3.5mm ETT from Portex® has an OD of 4.8mm).ConclusionsClinicians should be aware of the OD of ETTs to reduce unsuccessful intubation attempts caused by ETT sizes not fitting the nasal cavity. Generated data may help to adapt recommendations in future.Trial registrationSubgroup analysis of the “Fitting of Commonly Available Face Masks for Late Preterm and Term Infants (CAFF)”-study: NCT03369028, www.ClinicalTrials.gov, December 11, 2017.

Foreign body aspiration.

The clinical manifestations of foreign body (FB) aspiration can range from an asymptomatic presentation to a life-threatening emergency. Patients may present with acute onset cough, chest pain, breathlessness or sub-acutely with unexplained hemoptysis, non-resolving pneumonia and at times, as an incidental finding on imaging. Patients with iatrogenic FB such as an aspirated broken tooth during difficult intubation or a broken instrument are more common scenarios in the intensive care unit (ICU). Patients with post-obstructive pneumonia with or without sepsis, or variable degree of hemoptysis often require ICU level of care and bronchoscopic interventions. Rigid bronchoscopy has traditionally been the modality of choice; however, with the innovation in instrumentation and wider availability of flexible bronchoscopes, most of the FB removal is now successfully performed using flexible bronchoscopy. Proceduralists choose instruments in accordance with their training and expertise. We describe the use of most common instruments including forceps, balloon catheters, and baskets. Role of cryoprobe and LASER in FB removal is reviewed as well. In general, larger working channel bronchoscopes are preferred; however, smaller working channel bronchoscopes may be used in situations when the patients are intubated with a smaller diameter endotracheal or tracheostomy tubes. Large size FB are removed en bloc with the grasping tool, bronchoscope, and endotracheal or tracheostomy tube, requiring preparation to safely re-establish the airway. After FB removal, bronchoscopy is re-performed to identify any residual FB, assess any injury to the airway, suction post-obstructive secretions or pus, control any active bleeding and remove granulation tissue that may be obstructing the airway. Additional interventions like balloon dilatation may be required to dislodge an impacted FB or to maintain patency of bronchial lumen. If bronchoscopic methods fail, surgery may be required for retrieval of FB in symptomatic patients or to resect suppurative or necrotizing lung process. Multidisciplinary approach involving intensivists, surgeons, and anesthesiologists is the key to optimal patient outcomes.

The effect of the volumetric flow rate and endotracheal tube diameter on the pressure distribution in human airways

The comprehension of the fluid flow in the upper airways is of paramount importance when treating patients under clinical conditions that demand mechanical ventilation. Barotrauma and overdistension are related to undesirable pressures and might be responsible for morbidity and mortality. In the current work we use computational fluid dynamics to investigate the pressure field in the upper respiratory airways. We performed a set of simulations varying the volumetric flow rate of mechanical ventilators and we have shown that the pressure profile can be calculated by means of the volumetric flow rate in accordance with a mathematical expression given by Pav=aV˙2, where Pav is the average pressure at selected sections of the upper airways and V˙ is the volumetric flow rate. Numerical findings provide evidence that the constant a varies with the location of the plane in the upper airways. We also show that some particular diameters of endotracheal tubes (ETT) must be used with care for a given range of volumetric flow rates. Overall, we document an important relationship among pressure, volumetric flow rate and selected internal diameters from ETT.

Pediyatrik Hastalarda Uygun Endotrakeal Tüp Çapının Belirlenmesi: Distal Radius Epifiz Çapının ve Subglottik Çapın Kullanımı

INTRODUCTION: The aim of this study is to test the usefulness of epiphysis of distal radius measurement as a surrogate parameter for endotracheal tube (ETT) size prediction in children. METHODS: Seventy-three children were intubated with cuffed ETT selected according to age-based formula. Transvers diameter of epiphysis of distal radius and subglottic diameter of trachea were measured by ultrasound (US). Correlation between the outer diameter of best-fit endotracheal tube and transvers diameter of both radius epiphysis and subglottic diameter were calculated. The need for tube exchange, time for ultrasound (US) measurements and the ease level of measurements were compared. RESULTS: First attempt success at intubation was 83.6%. The correlation of the epiphysis diameter of the distal radius and best-fit ETT was significant (p&lt;0.001, r= 0.619, r2=0.383, 95% CI=0.419-0.838). Similarly the correlation of subglottic tracheal diameter and best-fit ETT was significant (p&lt;0.001, r=0.744, r2=0.553, 95% CI=0.678-825). Estimated ETT sizes according to radial epiphysis diameter and subglottic diameter were optimal in 82.2% and 94.5% respectively. Time for the US measurements of radial epiphysis and subglottic area were 38.3±9.6 and 24.9±4.6 seconds respectively (p&lt;0.001). The level of ease of US measurements were rated for radial epiphysis as 6 (5-9) and for subglottic area as 8 (7-9) (p&lt;0.001). DISCUSSION AND CONCLUSION: US measured transverse diameter of distal radius epiphysis resulted in similar success rate to age-based formula in our child population. Subglottic diameter measured by US estimates ETT size more accurately; it is also less time consuming and easier.

Energy transmission in mechanically ventilated children: a translational study

BackgroundRecurrent delivery of tidal mechanical energy (ME) inflicts ventilator-induced lung injury (VILI) when stress and strain exceed the limits of tissue tolerance. Mechanical power (MP) is the mathematical description of the ME delivered to the respiratory system over time. It is unknown how ME relates to underlying lung pathology and outcome in mechanically ventilated children. We therefore tested the hypothesis that ME per breath with tidal volume (Vt) normalized to bodyweight correlates with underlying lung pathology and to study the effect of resistance on the ME dissipated to the lung.MethodsWe analyzed routinely collected demographic, physiological, and laboratory data from deeply sedated and/or paralyzed children < 18 years with and without lung injury. Patients were stratified into respiratory system mechanic subgroups according to the Pediatric Mechanical Ventilation Consensus Conference (PEMVECC) definition. The association between MP, ME, lung pathology, and duration of mechanical ventilation as a primary outcome measure was analyzed adjusting for confounding variables and effect modifiers. The effect of endotracheal tube diameter (ETT) and airway resistance on energy dissipation to the lung was analyzed in a bench model with different lung compliance settings.ResultsData of 312 patients with a median age of 7.8 (1.7–44.2) months was analyzed. Age (p < 0.001), RR p < 0.001), and Vt < 0.001) were independently associated with MPrs. ME but not MP correlated significantly (p < 0.001) better with lung pathology. Competing risk regression analysis adjusting for PRISM III 24 h score and PEMVECC stratification showed that ME on day 1 or day 2 of MV but not MP was independently associated with the duration of mechanical ventilation. About 33% of all energy generated by the ventilator was transferred to the lung and highly dependent on lung compliance and airway resistance but not on endotracheal tube size (ETT) during pressure control (PC) ventilation.ConclusionsME better related to underlying lung pathology and patient outcome than MP. The delivery of generated energy to the lung was not dependent on ETT size during PC ventilation. Further studies are needed to identify injurious MErs thresholds in ventilated children.

A Retrospective Evaluation of Airway Anatomy in Young Children and Implications for One-Lung Ventilation

One-lung ventilation (OLV) in children remains a niche practice with few studies to guide best practices. The objective of this study was to describe lower airway anatomy relevant to establishment of OLV in young children. Retrospective, observational study using pre-existing studies in the electronic health record. Single institution, academic medical center, tertiary-care hospital. Pediatric patients <8 years old. None. Chest computed tomographic scans of 111 children 4 days to 8 years of age were reviewed. Measurements were taken from the thyroid isthmus to the carina, carina to first lobar branch on the left and right,diameter of the trachea at the carina, and diameter of the left and right mainstem bronchi. Dimensions were correlated with the outer diameter of endotracheal tubes and bronchial blockers. The left mainstem bronchus is consistently smaller than the right. Lung isolation using a mainstem technique on the left should use an endotracheal tube a half size smaller than would be used for tracheal intubation. The length from the carina to the first lobar branch on the left is consistently 3 times longer than on the right. Further, age-delineated bronchial diameters suggest that the clinician should transition from a 5F to a 7F Arndt bronchial blocker at 3-to-4 years of age. A more detailed and accurate understanding of pediatric lower airway anatomy may assist the clinician in successfully performing OLV in young children.

A Comprehensive Bench Assessment of Automatic Tube Compensation in ICU Ventilators for Better Clinical Management.

Automatic tube compensation (ATC) unloads endotracheal tube (ETT) resistance. We conducted a bench assessment of ATC functionality in ICU ventilators to improve clinical management. This study had 2 phases. First, we performed an international survey on the use of ATC in clinical practice, hypothesizing a rate of ATC use of 25%. Second, we tested 7 modern ICU ventilators in a lung model mimicking a normal subject (Normal), a subject with ARDS, and a subject with COPD. Inspiratory effort consisted of esophageal pressure over 30 consecutive breaths obtained in a real patient under weaning. A brand new 8-mm inner diameter ETT was attached to the lung model, and ATC was set at 100% compensation for the ETT. The 30 breaths were first run with ATC off and no ETT (ie, reference period), and then with ATC on and ETT (ie, active period). The primary end point was the difference in tidal volume (VT) between reference and active periods. We hypothesized that the VT difference should be equal to 0 in an ideally functioning ATC. VT difference was compared across ventilators and respiratory mechanics conditions using a linear mixed-effects model. The clinical use of ATC was 64% according to 644 individuals who responded to the international survey. The VT difference varied significantly across ventilators in all respiratory mechanics configurations. The divergence between VT difference and 0 was small but significant: the extreme median (interquartile range) values were -0.013 L (-0.019 to -0.002) in the COPD model and 0.056 L (0.051-0.06) in the Normal model. VT difference for all ventilators was 0.015 L (95% CI 0.013-0.018) in the ARDS model, which was significantly different from 0.021 L (95% CI 0.018-0.024) in the Normal model (P < .001) and 0.010 L (0.007-0.012) in the COPD model (P = .003). ATC is used more frequently in clinical practice than expected. In addition, VT delivery by ATC differed slightly though significantly between ventilators.

Airway ultrasound: Point of care in children-The time is now.

Point-of-care ultrasonography of the airway is becoming a first-line noninvasive adjunct assessment tool of the pediatric airway. It is defined as a focused and goal-directed portable ultrasonography brought to the patient and performed and interpreted on the spot by the provider. Successful use requires a thorough understanding of airway anatomy and ultrasound experience. To outline the many benefits, and some limitations, of airway ultrasonography in the clinical and perioperative setting. Expert review of the recent literature. Ultrasound assessment of the airway may provide the clinician with valuable information that is specific to the individual airway static and dynamic anatomy of the patient. Ultrasound can help identify vocal cord dysfunction and pathology, assess airway size, predict the appropriate diameter of endotracheal and tracheostomy tubes, differentiate tracheal from esophageal intubation, localize the cricothyroid membrane for emergency airway access and identify tracheal rings for US-guided tracheostomy. Ultrasonography is also a great tool for the intraoperative diagnosis of a pneumothorax, the visualization of the movement of the diaphragms, and quantifying the amount of gastric content. Ultrasonography signs, tips, and pearls that allow these diagnoses are highlighted. The major disadvantage of ultrasonography remains interobserver variability, and operator dependence, as it requires specific training and experience. Although it is not standard of care yet, there is significant potential for the integration of ultrasound technology into the routine care of the airway.

Patient factors associated with difficult flexible bronchoscopic intubation under general anesthesia: a prospective observational study.

Patient characteristics associated with difficult tracheal intubation using a flexible bronchoscope (FB) under general anesthesia have not been prospectively evaluated. This observational study aimed to identify demographic and morphologic factors associated with difficult FB intubation. We recruited 420 adult elective surgery patients undergoing tracheal intubation during general anesthesia. Patients characteristics were recorded including age, sex, weight, height, body mass index, American Society of Anesthesiologists physical status, history of snoring, obstructive sleep apnea, Mallampati score, upper lip bite test score, neck circumference and skinfold thickness, maximal neck flexion and extension angles, absence of teeth, Cormack and Lehane grade, presence of blood or secretions during intubation, as well as the inter-incisor, thyromental, sternothyroid, and manubriomental distances. The time (duration) needed to complete intubation (primary endpoint) and the number of attempts needed were correlated with these patient characteristics in a multivariable analysis. Intubation was successful on the first attempt in 409/420 patients (97%). Seven patients (1.7%) needed more than one attempt. Failure to intubate with the FB occurred in four patients (1%). A correlation was found between intubation duration and visibility impaired by secretions or blood (P < 0.001), higher neck skinfold thickness (P < 0.001), and larger endotracheal tube diameter (relative to a constant 5.5 mm FB; P < 0.001). The presence of secretions or blood that impair FB glottic visualization, a larger diameter endotracheal tube on the same size FB, as well as higher neck skinfold thickness may prolong the duration of FB intubation under general anesthesia. www.clinicaltrials.gov (NCT02769819); registered 5 May, 2016.