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Background: Reliable sealing of the pediatric airway requires appropriately sized tracheal tube cuffs. The aim of this study was to compare residual cuff diameters of pediatric tracheal tubes with pediatric airway dimensions., Methods: Cuff diameters of five different brands of locally marketed pediatric cuffed tracheal tubes with internal diameters of 3.0-7.0 mm were measured at a cuff pressure of 20 cm H 2 O and compared with cuff diameters indicated by their manufacturers. The latter values were compared to tracheal dimensions using the Motoyama and Khine formulas for cuffed tracheal tube size selection., Results: There is considerable heterogeneity in cuff diameters among pediatric tracheal tube brands, except for two brands from different manufacturers (Halyard and Parker Medical) which were identically designed. Cuffs made from polyurethane revealed fewer differences (91%-118%) between measured and manufacturer-indicated values for outer cuff diameters than did those made from polyvinylchloride (91%-146%). Particularly in smaller sized tracheal tubes, cuffs did not reach 100% of the tracheal lateral diameter, while others were oversized in larger tracheal tubes, independent of the two formulas used for cuffed tracheal tube size selection. Cuff diameters indicated by the manufacturer corresponded to 86%-188% of the median and 68%-157% of the maximum mid-tracheal lateral diameter of the corresponding upper age range., Conclusion: Our findings show that many of the cuff diameters of currently marketed tracheal tube brands lack an age-related anatomical rationale. A proposal for age-related anatomically based cuff diameters is provided for both recommendations for cuffed tracheal tube size selection in children., (© 2019 John Wiley & Sons Ltd.)

Background: Knowledge about airway dimensions during child growth is of paramount importance for pediatric clinical practice. Decisions about airway management in children are based on relatively limited, imprecise, or incomplete data about airway size., Aims: The aim of this work was to determine the anatomical development and size of airway structures from birth to adolescence using high-resolution computed tomography scans and to study the correlation between airway measurements and biometric data., Methods: We conducted a retrospective study of all high-resolution computed tomography scans including the respiratory tract, performed in our tertiary pediatric center (for reasons unrelated to airway symptoms) between June 1, 2016, and October 15, 2017, on children aged from 1 day to 14 years old. On each scan, 23 measurements of the larynx, trachea, and mainstem bronchi were performed. Patients were stratified into 16 groups according to their age. We calculated median value for each measurement in each group. Statistical models were calculated to explore correlation between measurements and age or weight., Results: A total of 192 scans were included (127 boys/65 girls). The mean age was 7 years. The correlations between airway measurements and age or weight were always significant. The relationship between measurements and age was found to be suitably represented by a cubic polynomial equation suggesting that the airway has a rapid growth phase in the first 3 years, followed by a slow growth phase and a second rapid growth phase during adolescence. The most relevant biometric parameter was age concerning 21 of the measurements., Conclusion: This comprehensive anatomical database of upper airway dimensions provides important data in the field of pediatric airway anatomy, particularly relating to the cricoid. We demonstrated that laryngeal, tracheal, and bronchial parameters correlate better to age and have three different growth phases., (© 2020 John Wiley & Sons Ltd.)

Background: 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., Aims: To outline the many benefits, and some limitations, of airway ultrasonography in the clinical and perioperative setting., Materials and Methods: Expert review of the recent literature., Results: 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., Conclusion: 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., (© 2020 John Wiley & Sons Ltd.)

Background: Age-related pediatric airway dimension reference values for cricoid, tracheal, and bronchial diameters as well as tracheal and bronchial lengths are essential for distinguishing normal from pathological airway findings and for manufacturing and selecting appropriately sized airway equipment., Aim: The aim of this work was to summarize and present existing pediatric airway dimension data for the larynx, trachea, and main stem bronchi from fetus to adolescence., Methods: A systematic literature search was carried out using PubMed, Scopus, Embase, and Google Scholar. Publications containing original data on pediatric airway dimensions as mean or median in tabular form and spanning narrow age groups of 1 or 2 years were included in our study. Original data such as diameters, lengths, and cross-sectional areas of trachea, cricoid, left and right main bronchi in fetuses and children were collected and presented as figures., Results: Pediatric airway dimension data were gathered and compiled from 15 studies fulfilling the inclusion criteria. Data were obtained from different measurement methods such as autopsy, chest X-ray, computed tomography, magnetic resonance imaging, rigid and flexible bronchoscopy as well as ultrasound examinations. There was considerable variation among age-related data due to biologic heterogeneity, different presentation of data, different definitions, and various measurement techniques., Conclusion: This investigation revealed heterogeneous data on pediatric airway dimensions, making it impossible to compile them into standard reference values for airway dimensions. New studies with structured and standardized measurements and data presentation in large populations of children are required to provide more valid pediatric airway dimension data., (© 2019 John Wiley & Sons Ltd.)

Background: Studies have shown significant variation in the tracheobronchial angles in pediatric-aged patients. The current study revisits tracheobronchial angle measurements in children using accurate computed tomography-based 3-dimensional images to add clarity to the understanding of tracheobronchial angles. The primary objective of the current study was to measure the right and left bronchial angle take off from the trachea using 3-dimensional computed tomography-based images of the air column in the tracheobronchial tree., Methods: Computed tomography-based images of 45 children younger than 8 years were reviewed. The children were evaluated during spontaneous ventilation either during natural sleep or with sedation. The right and left bronchial angles were computed between the central axes of the respective main bronchi and a vertical line passing through the central axis of the longitudinal tracheal air column. The right and left bronchial angles were compared using paired t tests, and the age dependence of the right bronchial angle and left bronchial angle difference was evaluated using Pearson's correlation coefficient., Results: The study cohort included 18 males and 27 females with an average age of 49 ± 25 months. The right bronchial angle ranged from 23° to 56° (mean 42 ± 7°), whereas left bronchial angle varied between 25° and 68° (mean 43 ± 9°). The difference in means of 1 degree was not statistically significant (95% confidence interval of difference: -1°, 4°; P = .282). No association was found between left and right bronchial angle difference and patient age (r = -.019)., Conclusion: According to computed tomography-based 3-dimensional imaging, right and left bronchial angles are virtually identical in children up to 8 years of age, and the difference between right and left bronchial angles does not vary with age in this population., (© 2018 John Wiley & Sons Ltd.)

Background: Adequate endotracheal tube positioning in preterm infants is complicated by the short length of the airway. Distal markers were designed to help with the insertion of endotracheal tubes at an appropriate depth below the vocal cords. However, those markers are not standardized between manufacturers, each tube size displays only one (sometimes 2) markers to provide information for infants of various gestational ages, and indicated distances are often too long for extremely preterm infants., Aims: The study aims to describe vocal cords to mid-tracheal distance for different gestational ages and determine if depth markers should be adjusted accordingly., Methods: Half the tracheal length added to the height of the posterior lamina of the cricoids approximates the distance between vocal cords and mid-trachea. Those dimensions were retrospectively retrieved from a database of laryngo-tracheal measurements obtained during autopsies of fetuses and newborn infants free of upper airway malformations. The equation of correlation between gestational age and distance from vocal cords to mid-trachea was used to calculate those distances for different gestational ages., Results: Data were derived from 114 patients. Vocal cords to mid-trachea distance is linearly correlated with gestational age (r = .90; distance = 2.831 + 0.6208 × gestational age). We suggest depth markers at 17.7, 19.0, 20.8, 22.7, 24.6, and 26.4 mm for gestational ages of 24, 26, 29, 32, 35, and 38 weeks, respectively, indicated by contrasting colors., Conclusion: The linear relationship between laryngo-tracheal size and gestational age offers the opportunity to revise endotracheal tube depth markers for the smallest patients. Trials comparing those suggested markers with those currently in use are needed before implementation., (© 2018 John Wiley & Sons Ltd.)

Background: The aim of this study was to obtain lower airway dimensions in children by means of computed tomography (CT)., Methods: Chest CT scans from 195 pediatric patients (118 boys/77 girls) aged 0.04-15.99 years were analyzed. Tracheal and bronchial lengths, anterior-posterior and lateral diameters, as well as cross-sectional area were assessed at the following levels: mid trachea, right proximal and distal bronchus, proximal bronchus intermedius, and left proximal and distal bronchus. Mediastinal angles of tracheal bifurcation were measured. Data were analyzed by means of linear and polynomial regression plots., Results: The strongest correlations were found between tracheal and bronchial diameters and age as well as between tracheal and bronchial lengths and body length. All measured airway parameters correlated poorly to body weight. Bronchial angles revealed no association with patient's age, body length, or weight., Conclusion: This comprehensive anatomical database of lower airway dimensions demonstrates that tracheal and bronchial diameters correlate better to age, and that tracheal and bronchial length correlate better to body length. All measured airway parameters correlated poorly to body weight., (© 2017 John Wiley & Sons Ltd.)

Background: The aim of this prospective study was to investigate the success of ultrasound in pediatric patients in determining the appropriate sized cuffed endotracheal tube and to compare the results with conventional height-based (Broselow) tape and age-based formula tube size., Methods: One hundred and fifty-two children of 1-10 years of age, who received general anesthesia for adenotonsillectomy were enrolled to the study. In all participants, the transverse diameter of the subglottis was measured with ultrasound during apnea. An endotracheal tube was chosen with the outer diameter matched to the measured subglottic airway diameter. An age-based (Motoyama-Khine) and height-based (Broselow) endotracheal tube size was calculated. If there was resistance to passage of the tube into the trachea or an airway pressure >25 cmH 2 0 was required to detect an audible leak, the endotracheal tube was replaced with internal diameter of 0.5 mm smaller. If there was an audible leak at airway pressure <10 cmH 2 O, or peak pressure >25 cmH 2 0 or a cuff pressure > 25 cmH 2 O was required to seal, the tube was changed to the 0.5 mm larger internal diameter. Best-fit tube internal diameter was the resultant tube internal diameter that met the previously stated conditions. The need for endotracheal tube replacement and peak airway pressure were recorded., Results: The internal diameter of ultrasound determined tube was the same as best-fit tube in 88% of children. Endotracheal tube was replaced in 15 patients with a one size larger, and in three patients with one size smaller tube. Using Bland-Altman analysis, a better agreement was observed with ultrasound measurement rather than height-based estimation and age-based formulas., Conclusion: Our findings show that subglottic diameter measured by ultrasound appears to be a reliable predictor for the assessment of the subglottic diameter of the airway in estimating appropriate size pediatric endotracheal tube., (© 2017 John Wiley & Sons Ltd.)

Introduction: Computed tomography- (CT) and magnetic resonance imaging (MRI)-based measurements have recently suggested that the narrowest dimension of the pediatric airway is the subglottic region. These data are contrary to the previously held tenets of a funnel- or conical-shaped airway. The current study evaluates airway volumes and shapes using three-dimensional CT images of the air way column in spontaneously breathing children., Methods: The study included CT-based radiological images of the neck in children who required imaging unrelated to airway symptomatology. The children were evaluated during spontaneous ventilation during natural sleep or with sedation without airway devices in place. The three-dimensional images of the airway column were evaluated, volumes calculated, and comparisons made between the subglottic, cricoid, and tracheal volumes and shapes., Results: The study cohort included 54 children, ranging in age from 2 months to 8 years. An increase in the airway volumes was observed from the subglottic (0.17 ± 0.06 mm 3 ) to the cricoid (0.19 ± 0.06 mm 3 ) to the tracheal regions (0.22 ± 0.07 mm 3 ). The volumes of the subglottic, cricoid, and tracheal regions demonstrated a linear relationship with age., Conclusion: This study confirms recent studies demonstrating that the subglottic region not the cricoid is the narrowest part of the airway., (© 2017 John Wiley & Sons Ltd.)

Background: Recent studies suggest that the pediatric airway is elliptical with the subglottis rather than the cricoid as the narrowest part contrary to the old belief of a funnel-shaped airway. The shape of the airway in neonates and infants has not been studied separately. This study seeks to define the shape of the upper airway in neonates and infants, and determine if there are differences in airway shape between infants and older children., Methods: We studied 40 computed tomographic scans of children from birth to 12 months of age undergoing radiological evaluation unrelated to airway symptomatology. The computed tomographic scans were obtained during either natural sleep or with sedation and spontaneous ventilation without airway devices in place. Transverse and anteroposterior diameters were measured at the subglottic level and at the cricoid ring., Results: The mean age was 5.9 ± 3.4 months. The mean transverse and anteroposterior diameters were 5.3 ± 0.83 mm and 7.2 ± 0.89 mm at the subglottic region and 6.1 ± 0.86 mm and 6.7 ± 0.79 mm at the cricoid level. An increase in the transverse dimension of the airway was observed from the subglottic region to the cricoid ring. Although the anteroposterior dimension decreased from the subglottis to the cricoid ring, the airway remained wider in the anteroposterior dimension compared to the transverse dimension from the subglottis to the cricoid ring., Conclusion: The present study demonstrates that the airway in neonates and infants between the subglottic area and the cricoid remains elliptical. The cricoid is not round as has been observed in older children. The airway is wider anteroposteriorly and narrows in the transverse dimension from the subglottis to the cricoid in infants., (© 2017 John Wiley & Sons Ltd.)

Background: Optimal positioning of endotracheal tubes (ETTs) decreases the risk of accidental extubation or endobronchial intubation. This study evaluated the usefulness of external anatomical landmarks as practical references for determining an insertion depth of an ETT in pediatric patients., Methods: Computed tomography images of the necks of 183 pediatric patients (≤16 years of age) were reviewed. Levels corresponding to the vocal cords, cricoid cartilage, suprasternal notch, manubriosternal junction, and carina were identified on sagittal reconstructed images. The surface measurements from the cricoid cartilage to the suprasternal notch and that from the suprasternal notch to the manubriosternal junction were determined. Bland-Altman analysis was used to interpret the relationship between the midtracheal level and the surface measurements., Results: The difference between the midtracheal level and the surface distance from the cricoid cartilage to the suprasternal notch was 3.5 ± 7.0 mm, which was closer to zero than that between the midtracheal level and the surface distance from the suprasternal notch to the manubriosternal junction of 15.1 ± 6.1 mm., Conclusion: The midtracheal level, helpful in planning the insertion depth of an ETT, can be predicted by measuring the surface distance from the cricoid cartilage to suprasternal notch in pediatric patients., (© 2016 John Wiley & Sons Ltd.)

Background: It is challenging for anesthetists to determine the optimal tracheal intubation depth in children. We hypothesize that a measure three times the length of the middle finger can be used for predicting tracheal tube depth in children., Methods: Eighty-six children (4-14 years of age) were included in this study. After the children were anesthetized, a fiberoptic bronchoscope (FOB) was inserted into the trachea, the lengths from the upper incisor teeth to carina and vocal cords were measured, and a suitably sized cuffed tracheal tube was inserted into the trachea. Age-based and middle finger length-based formulas were used to determine the tracheal intubation depth., Results: All 86 children enrolled were included in this study. Compared with the age-based intubation, the rate of appropriate tube placement was higher for middle finger length-based intubation (88.37% vs 66.28%, P = 0.001). The proximal intubation rate was lower in middle finger length-based intubation (4.65% vs 32.56%, P < 0.001). There was only weak evidence for a difference in the distal intubation rate between the two methods (6.97% vs 1.16%, P = 0.054). The correlation coefficient between middle finger length and optimal tracheal tube depth was larger than that between age and optimal tracheal tube depth (0.883 vs 0.845)., Conclusions: Our data indicate that the appropriate tube placement rate can be improved by using three times the middle finger length as the tracheal intubation depth in children., (© 2015 John Wiley & Sons Ltd.)

Background: Accurate positioning of the tip of the tracheal tube (tube tip) is challenging in young children. Prevalent clinical methods include placement of intubation depth marks, palpation of the tube cuff in the suprasternal notch, or deliberate mainstem intubation with subsequent withdrawal. To compare the predictability of tube tip positions, variability of the resulting positions in relation to the carina was determined applying the three techniques in each patient., Methods: In 68 healthy children aged ≤4 years, intubation was performed with an age-adapted, high-volume low-pressure cuffed tube adjusting the imprinted depth mark to the level of the vocal cords. The tube tip-to-carina distance was measured endoscopically. Thereafter, placements using (I) cuff palpation in the suprasternal notch and (II) auscultation to determine change in breath sounds during withdrawal after bronchial mainstem intubation were completed in random order., Results: Tube tip position above the carina was higher when using depth marks (mean = 36.8 mm) compared with cuff palpation in the suprasternal notch (mean = 19.0 mm). Variability, expressed as sd, was lowest with the mainstem intubation technique (5.2 mm) followed by the cuff palpation (7.4 mm) and the depth mark technique (11.2 mm) (P < 0.005)., Conclusion: Auscultation after deliberate mainstem intubation and cuff palpation resulted in a tube tip position above the carina that was shorter and more predictable than placement of the tube using depth markings., (© 2014 John Wiley & Sons Ltd.)

Background: Accurate endotracheal tube (ETT) depth is critical, especially in children. The current tools used to guide appropriate ETT depth have significant limitations., Objectives: To evaluate the utility of tracheal palpation in the neck to guide appropriate ETT placement in children., Methods: A prospective observational study with a convenience sample of 50 children was conducted. During intubation, an investigator palpated the trachea with three fingertips side-by-side extending upward from the suprasternal notch. The anesthesiologist advanced the ETT slowly until palpated at the sternal notch. The investigator stated ETT palpation certainty as 'strongly felt', 'weakly felt', or 'not felt.' Final ETT position was determined by bronchoscopy and categorized as 'ETT too shallow' (tip in proximal ¼ of trachea), 'ETT too deep' (tip in distal ¼ of trachea), or 'ETT placement satisfactory' (between those extremes)., Results: Thirty boys and 20 girls undergoing dental surgery with nasal intubation were recruited (median age 4.4 years; range 2.0-10.8). The ETT (all ≥4 mm ID) was palpable at the sternal notch in all patients: 46 of 50 strongly palpable and 4 of 50 weakly palpable. The experimental methods led to satisfactory ETT placement in 49 of 50 patients, too deep in 1 of 50 patients. Compared with the Pediatrics Advanced Life Support (PALS) predictive formula, satisfactory placement would have been 41 of 50 patients (P < 0.008). Number needed to treat is 6.3 for improvement over the PALS method., Conclusions: The use of tracheal palpation to guide ETT placement has excellent clinical performance and better guides appropriate ETT depth than the PALS formula in our study population., (© 2014 John Wiley & Sons Ltd.)

Background: The increasing opportunities to consider fetal intervention in selected cases of life-threatening malformations have necessitated airway management of fetuses with low gestational age. This study is aimed to determine the anatomical dimensions of trachea, main bronchi, subcarinal and bronchial angles and their correlation to age and crown rump length (CRL) in fetuses., Methods: Measurements of tracheo-bronchial dimensions including the subcarinal and bronchial angles with the vertical were taken in specimens obtained from 40 fetuses, varying in CRL from 61 to 270 mm. The incidence of different shapes at the upper end of trachea was studied. The subcarinal and angles of main bronchi with the vertical were measured radiographically with 20% barium sulfate, in another group of 21 fetuses varying in CRL from 63 to 129 mm., Results: Forty fetuses (22 males, 18 females) were analyzed for the dimensions based on CRL (61-130 mm; 131-200 mm; 201-270 mm--CRL 1, 2, and 3 respectively). The internal transverse diameter of trachea was found to increase steadily from 1.87 +/- 0.56 to 2.67 +/- 0.7 mm (P < 0.001) and 3.68 +/- 0.39 mm (P < 0.001) with increasing CRL. Similarly the outer transverse and antero-posterior diameter of the trachea increased steadily with age. Tracheal length was found to increase significantly to 17.48 +/- 2.89 mm and 24.17 +/- 2.3 from 12.72 +/- 2.5 mm (P < 0.001). The length of paries membranaceous increased with gestational age. Although the length of bronchi increased significantly and linearly, subcarinal and bronchial angles did not show any significant changes with age. There was no sexual dimorphism in measurements in the fetuses of corresponding CRL. Oval shaped trachea was found in 60% and circular in 40% of fetuses. The measurements of subcarinal and bronchial angles performed by radiology were almost the same as those measured in trachea separated from fetuses., Conclusion: The internal transverse, outer transverse and antero-posterior diameters, length of trachea and bronchi and circumference of trachea, relate in a linear fashion to CRL and age. However, subcarinal and bronchial angles remained constant.

Background: Pediatric airway management decisions are based primarily on results derived from indirect measures of laryngeal and tracheal dimensions. More recent methods could provide more direct information about absolute and relative changes in airway dimensions associated with growth and development., Study Objectives: The aims of this study were (i) to determine whether a 'video-bronchoscopic' measurement method could be used to reliably measure airway dimensions in children and (ii) to provide a preliminary assessment of dimensions of the glottis and cricoid in children of various ages., Methods: Following approval from the institutional review board, validation experiments were performed to determine whether measurements obtained from the video image from the bronchoscope provided accurate measurements of tubular objects of known dimensions. The reliability of the measurements was determined by using two independent trained observers to measure video-bronchoscopic images of the larynx at the level of the glottis and the cricoid in 11 children. The observers measured the video-bronchoscopic images and airway measurements were obtained in 16 additional children to determine the utility of the measurement method., Results: There was good agreement between the direct and video-bronchoscopic measurement techniques (Bland and Altman plot) for both the cross-sectional area (CSA) and the diameter of objects. The interobserver measures for cricoid and glottis were reproducible as indicated by the concordance correlation coefficient (CCC) for cricoid anteroposterior diameter (CCC = 0.98, r = 0.98, accuracy = 0.99) and transverse diameter (CCC = 0.93, r = 0.8, accuracy = 0.99) as well as for the glottic anteroposterior diameter (r = 0.8, accuracy = 0.8, CCC = 0.6) and the glottic transverse diameter(r = 0.8, accuracy = 0.74, CCC = 0.6). Overall, for the 27 children studied [mean age 73 months (+/-24.7, range 30-140], the mean value of the cricoid CSA [45.3 mm(2) (+/-13.9)] was found to be greater than the glottic CSA [16.2 mm(2) (+/-10.1)]., Conclusions: The video-bronchoscopic imaging method provided an accurate, reliable measure of pediatric airway dimensions. This technique could be applied to assess absolute and relative airway size associated with growth and development. The relationship between glottic and cricoid dimensions during growth and development in children needs further investigation across various age groups.

Background: Cardiac tamponade is rare but one of the most serious complications in relation to central venous catheters (CVC). The tip of the CVC should be placed outside the pericardium to avoid tamponade. In adults, the carina is always located above the pericardium; therefore, the carina is a reliable landmark for CVC placement. We examined whether the carina could also be an adequate landmark for CVC placement in neonates., Methods: The study was conducted using nine fresh neonatal cadavers. The longitudinal distance between the carina and the pericardium as it transverses the superior vena cava (the pericardial reflection: PR) was measured., Results: The median postconceptional age (gestational age in weeks + weeks after delivery) at autopsy was 35 (range: 23-42) weeks. The PR was located at a distance of 4 mm above to 5 mm below the carina. Unlike in adults, the position of the PR varies in relation to the carina in neonates. In seven of the nine subjects, the location of the PR was above the carina., Conclusions: In neonates, the carina is not always located above the pericardium, as it is in adults; therefore, the carina is not an appropriate landmark for CVC placement.

Background: The aim of this study was to determine the accuracy of standard techniques for estimating oral and nasal tracheal tube length in children and to devise more accurate predictive formulae that can be used at the bedside., Methods: Data were collected from 255 children who required tracheal intubation whilst on the Pediatric Intensive Care Unit over a period of 1 year. Age, weight, the final length of the tracheal tube and the internal diameter were documented. Patients with a tracheostomy were excluded from the study., Results: Using linear regression the following formulae best predicted final tracheal tube length. For children over 1 year of age: Insertion depth (cm) for orotracheal intubation = age/2 + 13 Insertion depth (cm) for nasotracheal intubation = age/2 + 15 For children below 1 year of age: Insertion depth of orotracheal tube (cm) = weight/2 + 8 Insertion depth of nasotracheal tube (cm) = weight/2 + 9, Conclusions: Current Advanced Paediatric Life Support guidelines underestimate the appropriate tracheal tube lengths for orotracheal intubation in children over 1 year of age. Similarly, the novel weight-based formulae for tracheal tube lengths in children below the age of 1 year proved more accurate than standard reference charts. We therefore recommend that these new formulae are prospectively evaluated.

Background: In preformed cuffed tracheal tubes the position of the cuff within the airway is given by its distance to the tube bend placed at the lower teeth. The aim of this study was to compare the design of cuffed and uncuffed preformed pediatric oral tracheal tubes with regard to anatomical landmarks., Methods: Complete series of cuffed and uncuffed preformed oral pediatric tracheal tubes sized from internal diameter 3.0-7.0 mm if available were ordered from five different manufacturers. The distance from the bend to the distal tube tip and to the upper border of the cuff were measured and compared with anatomical airway landmarks in the developing child., Results: Between cuffed and uncuffed tracheal preformed tubes up to 37 mm differences in the bend-to-tracheal tube tip distances were found for given age groups. Thus uncuffed preformed tracheal tubes were more at risk for inadvertent endobronchial intubation than cuffed preformed tracheal tubes. Comparison of bend-to-upper border of the cuff distances with teeth-to-vocal cord distances calculated from anatomical data revealed that several of the tracheal tube cuffs become positioned within the subglottic larynx or even within the vocal cords when inserted according to the bend., Conclusions: There is a need for improvement in cuffed preformed pediatric tracheal tubes, namely a standard bend-to-tracheal tube tip distance to allow a safe insertion depth, a short cuff placed on the tube shaft as distally as possible and an intubation depth mark to verify a proper position of the cuff in the trachea.

Unanticipated difficult intubation in asymptomatic infants is a rare event. Most infants with congenital tracheal anomalies will present with airway problems. We present a case of failed intubation in an asymptomatic 8-day-old infant with complete tracheal rings. The infant could be ventilated with an LMA and surgery for placement of a ventricular-peritoneum shunt was completed. This is a report of the case and review of the literature.