Endotracheal Tube Size Research Articles

Computed tomographic laryngotracheal dimensions in adult domestic rabbits (Oryctolagus cuniculus) are positively associated with body weight and the laryngotracheal lumen is narrowest at the level of the thyroid cartilage.

This retrospective study aimed to measure rabbit laryngotracheal dimensions at different locations on computed tomography (CT), assess the relationship of these measurements with rabbit body weight, determine the most common narrowest measurement and assess its relationship with endotracheal tube (ETT) size and body weight. 66 adult domestic rabbits (Oryctolagus cuniculus) of different breeds and body weights. CT laryngotracheal luminal height, width, and cross-sectional area measurements were made at the rostral thyroid cartilage at the level of the arytenoids, caudal thyroid cartilage/rostral cricoid cartilage, caudal cricoid cartilage/cranial trachea, and trachea at the level of the fifth cervical vertebra. The data for every measurement of luminal airway dimensions revealed robust positive associations with body weight (P < .001). The narrowest laryngotracheal measurement was the width at the level of the caudal thyroid cartilage/rostral cricoid cartilage, and the smallest cross-sectional area was at the rostral thyroid cartilage at the level of the arytenoids. There was a strong association between body weight and the likelihood of appropriate ETT fit. To have at least an 80% chance of appropriate ETT fit with a 2.0, 2.5, and 3.0 mm ETT, the rabbits' weight predicted by the model (lower 95% confidence limit) were at least 2.99 (2.72) kg, 5.24 (4.65) kg, and 5.80 (5.21) kg, respectively. The laryngotracheal lumen was narrowest at the level of the caudal thyroid cartilage in rabbits, which indicates this location may be the limiting factor in determining ETT size in rabbits.

Goldenhar syndrome complicated with subglottic airway stenosis: a case report

BackgroundGoldenhar syndrome is a congenital disease that involves an absence or underdevelopment of structures that arise from the first and second pharyngeal arches and more or less severe extracranial anomalies. A variety of supraglottic malformations may be observed, including mandibular hypoplasia, mandibular asymmetry and micrognathia. Subglottic airway stenosis (SGS), which can cause difficulties in airway management during the perioperative period, is seldom emphasized in literature descriptions of Goldenhar syndrome, but can be clinically significant.Case presentationAn 18-year-old female with a history of Goldenhar syndrome presented for placement of a right mandibular distractor, right retroauricular dilator, and stage I transfer of a prefabricated expanded flap under general anesthesia. During tracheal intubation, the endotracheal tube (ETT) met resistance unexpectantly when attempting to pass through the glottis. Subsequently, we attempted the procedure with a smaller size ETT but again met resistance. With fiberoptic bronchoscope, we found that the whole segment of the trachea and bilateral bronchi were obvious narrow. Given the finding of unexpected severe airway stenosis and the associated risks with proceeding with the surgery, the operation was cancelled. We removed the ETT once the patient was fully awake.ConclusionsAnesthesiologists should be aware of this clinical finding when evaluating the airway of a patient with Goldenhar syndrome. Coronal and sagittal measurements on computerized tomography (CT) and three-dimensional image reconstruction can be used to evaluate the degree of subglottic airway stenosis and measure the diameter of the trachea.

Comparative study of different formulae for prediction of best fit endotracheal tube size in children

BackgroundVarious formulae have been used to predict appropriate endotracheal tube (ETT) size in children, but there is no consensus regarding the best predictor. Recent use of ultrasonography (USG) to predict the ETT size may not always be feasible leaving the physical parameters as most useful and practical option. The present study was planned to compare age-, height- and weight-based formulae for ETT size prediction in children.ResultsThe accuracy in predicting ETT size was found to be 88.67%, 73.33% and 32.67% for height-based formula (HBF), age-based formula (ABF) and weight-based formula (WBF), respectively. Pearson correlation coefficient was best for HBF (0.968 with 95% CI of 0.937–0.999), followed by ABF (0.942 with 95% CI of 0.887–0.996) and WBF (0.874 with 95% CI of 0.794–0.953). HBF was found to be best suited for children 1–3 years, ≤ 90 cm and weight < 15 kg with accuracy of > 98%, while WBF was unsatisfactory across all age, height and weight groups.ConclusionsHBF is the best predictor of ETT size across all age groups with marginal superiority over ABF, especially in age group < 3 years. WBF was least effective in predicting ideal ETT size. It is recommended that HBF should be preferred over ABF and WBF for selection of ETT size in paediatric patients. This practice assumes greater importance especially in emergency situations where exact age and weight cannot be ascertained while height is easily obtainable.

Incidence and risk factors for postoperative sore throat after general anesthesia with endotracheal intubation: prospective cohort study.

To determine the prevalence and risk factors of POST following endotracheal intubation under general anaesthesia. From 20 April to 20 May 2021, a multicenter prospective cohort study design and systematic random sampling were used to select study participants from patients over the age of 18 who underwent anaesthesia-assisted surgery with endotracheal intubation. A structured questionnaire was developed after reading some of the relevant literature. SPSS version 20 was used to enter and analyze the data, and binary logistic regression was used to select a variable for multivariable logistic regression. To identify statistically significant factors, a P value of 0.05 for the association between the independent and dependent variables was used in multivariable analysis. Sore throat occurred in 94 (61.8%) of the 152 patients who had undergone surgery under general anaesthesia with endotracheal intubation. The size of the endotracheal intubation was found to have a p value of 0.04, (adjusted odds ratio 0.04, 95% CI 0.002-0.79), and the duration of the anaesthesia was found to have a p value of 0.003, (adjusted odds ratio 4.5, 95% CI 1.66-12.18). The POST was associated with a large endotracheal tube, patient age, and an extended period of anaesthesia in this study, with a prevalence of 94 (61.8%) cases. In this study, the incidence of POST was high 94 (61.8%), large size endotracheal tube, patient age, and duration of anaesthesia were associated factors for POST. Awareness creation through training based on research findings should be made about the problem for all health professionals who were involved in postoperative patient care.

Evolving Endotracheal Tube Preferences and Practices: Intensivist Knowledge Gaps and Sex Disparities.

The complex management of intubation-related laryngeal injury makes prevention vital. The purpose of this study is to assess endotracheal tube (ETT) practices and preferences among intensivists at our institution. Chart review of intubated patients and intensivist survey were simultaneously performed in January 2016 and August 2022. A height-to-ETT size ratio (H:ETT) was calculated for each patient in the 2022 cohort. Intubated patients were followed until tracheostomy, extubation, or death occurred. Surveys assessed intensivist preferences for ETT size and management of intubated patients. 300 ICU patients were included. The mean ETT size for males decreased from 7.73 ± 0.30 in 2016 to 7.57 ± 0.25 in 2022 (p < 0.001). The average H:ETT of men was higher than females (p = 0.004), indicating that females in this population were intubated with larger ETTs relative to their height compared to males. Whereas the majority (66.7%) of intensivists endorse 7.0 ETTs as the standard for women, the majority (70%) of women at our institution are intubated with a 7.5 ETT or larger. Of intubated patients in the ICU, 23 (19.5%) were intubated for 11 days or longer. Compared to men, women are intubated with larger-than-preferred ETTs relative to height. Additionally, patients in our study were intubated for longer than preferred based on intensivist surveys, putting this population at higher risk for acute laryngeal injury (AlgI)-related laryngotracheal stenosis (LTS). Further studies should seek to identify similar trends and barriers to reducing ALgI-related LTS. 3 Laryngoscope, 133:3080-3086, 2023.

Postmortem Identification of Vascular Ehlers-Danlos Syndrome in a Lung Transplant Recipient.

Postmortem Identification of Vascular Ehlers-Danlos Syndrome in a Lung Transplant Recipient.

Comparison of Accuracy of Ultrasound Measurement of Subglottic Diameter Versus Conventional Age Based Formula for Estimating Endotracheal Tube Size for Pediatric Surgical Patients- A Prospective Randomized Controlled Study

Introduction: The main aim of this study is to determine if ultrasonography (USG) based measurement of subglottic diameter is the best size predictor for endotracheal tube (ETT) in pediatric surgical cases over age-based formula with micro cuff tube. Also, to test reintubation percentage and post-operative complications in children. Methodology: This research is double-blind randomized control study with 68 children undergoing elective surgery requiring general anaesthesia with micro cuff tube. They were divided into 2 groups i.e. ETT size by USG (group U) and ETT size by age-based formula group A) (with 34 children in each. Both groups ETT measurement was calculated by independent Samples t-test, and correlation of both groups with actual ET Tube was measured by Pearson’s correlation coefficient. Reintubations or post-op complications was measured by Chi-squared test. Results: Mean age of group A and U are 5.65 ± 2.77 and 5.97 ± 2.77 respectively. Mean weights were from 13.5±2.06 kgs to 27±4.63kgs. Statistical significance with a P-value (P=0.0460) is observed in group U whereas no significance was seen in group A. A strong positive correlation (R=0.960) between USG-estimated ETT size and actual ETT size is observed. The difference in reintubations and post-op complications in group U were statistically significant with P &lt; 0.002. Conclusion: The present study concludes that the sub glottis diameter measured by USG is a good predictor for correct size of micro cuff endo tracheal tube in children.

Risk factors for developing subglottic and tracheal stenosis from the medical intensive care unit.

Endotracheal intubation is a common procedure in the medical intensive care unit (MICU), but it carries risk of complications including, but not limited to, subglottic stenosis (SGS) and tracheal stenosis (TS). Current literature suggests identifiable risk factors for the development of airway complications. This study is a comprehensive evaluation of potential risk factors in patients who developed SGS and TS following endotracheal intubation in our MICU. Patients intubated in our MICU were identified from 2013 to 2019. Diagnoses of SGS or TS within 1 year of MICU admission were identified. Data extracted included age, sex, body measurements, comorbidities, bronchoscopies, endotracheal tube size, tracheostomy, social history, and medications. Patients with prior diagnosis of airway complication, tracheostomy, or head and neck cancer were excluded. Univariate and multivariate logistic regressions were performed. A total of 136 patients with TS or SGS were identified out of a sample of 6603 patients intubated in the MICU. Cases were matched to controls who did not develop airway stenosis based on identical Charlson Comorbidity Index scores. Eighty six controls were identified with a complete record of endotracheal/tracheostomy tube size, airway procedures, sociodemographic data, and medical diagnosis. Regression analysis showed that SGS or TS were associated with tracheostomy, bronchoscopy, chronic obstructive pulmonary disease, current tobacco use, gastroesophageal reflux disease, systemic lupus erythematosus, pneumonia, bronchitis, and numerous medication classes. Various conditions, procedures, and medications are associated with an increased risk of developing SGS or TS. 4.

Erratum: Endotracheal Intubation Using a Flexible Intubation Endoscope As a Standardized Model for Safe Airway Management in Swine.

Erratum: Endotracheal Intubation Using a Flexible Intubation Endoscope As a Standardized Model for Safe Airway Management in Swine.

Association of Educational Intervention With Knowledge of Airway Injury After Endotracheal Intubation and Tube Size Selection

In this nonrandomized controlled trial, an educational intervention for emergency medicine residents was developed to increase knowledge of airway injury following prolonged intubation and reduce the proportion of large-for-height endotracheal tubes placed in the emergency department.

RAE ENDOTRACHEAL TUBES SIZES FOR CHILDREN UNDERGOING CLEFT LIP AND PALATE SURGERY.

Background: Appropriate sizes (internal diameters) of RAE endotracheal tubes in children with cleft lip and palate, who generally have delayed growth and development in early infancy have not been explained. Objectives: The aim of the current study was to identify the proper size of REA endotracheal tube for intubation used for cleft lip and palate surgery and intubation outcomes in these patients. Material and methods: 60 cleft lip and palate patients were selected for analytic cross-sectional study. The proper tube size was determined by normal children formula. Then tube size was confirmed by patients' minimum resistance to intubation, proper ventilation, and appropriate air leakage at an airway pressure of 15-20 cm H2O. Number of attempts of intubation and the largest endotracheal tube size were recorded. Results: The average age, weight and height of patients were 22.40±4.85 months, 9.88±1.28 kg, 72.40±24.50 cm respectively. The average RAE endotracheal tube size and frequency of intubation trials were 4.25±0.78 and 1.62±0.70, respectively. 6 cases required RAE endotracheal tube size smaller than the recommended size. Conclusions: In cleft lip and plate child, the predicted RAE endotracheal tube size was similar to standard normal child tube size. Smaller RAE tube size was required for subglottic stenosis.

Applications of Airway Ultrasound for Endotracheal Intubation in Pediatric Patients: A Systematic Review

Endotracheal intubation is a challenging procedure for pediatric patients. Airway ultrasound as a new technology is suitable for aiding this process, but its diagnostic value remains unclear. We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and the Chinese biomedical literature database to summarize specific applications of airway ultrasound in each step of endotracheal intubation in pediatric patients. Diagnostic accuracy and 95% confidence interval were used as outcomes. In total, 33 studies (6 randomized controlled trials and 27 diagnostic studies) with 1934 airway ultrasound examinations were included. Population included neonates, infants, and older children. Airway ultrasound could be used to determine the endotracheal tube size and confirm endotracheal intubation and intubation depth; the diagnostic accuracy for all these factors was 23.3-100%, 90.6-100%, and 66.7-100%, respectively. Furthermore, the accuracy of airway ultrasound in predicting endotracheal tube size was consistently higher than traditional methods, such as height formula, age formula, and the width of the little finger. In conclusion, airway ultrasound has unique advantages for confirming successful endotracheal intubation in pediatric patients, and it may become an effective auxiliary tool in this field. There is a need to develop a unified airway ultrasound protocol to conduct clinical trials and practice in the future.

Applicability of the Broselow Pediatric Emergency Tape to Predict the Size of Endotracheal Tube and Laryngeal Mask Airway in Pediatric Patients Undergoing Surgery: A Retrospective Analysis.

Background This study aims to elucidate the applicability of the Broselow pediatric emergency tape in predicting the size of the endotracheal tube (ET) and laryngeal mask airway (LMA) in children of central India. Methods A retrospective review was conducted in the Department of Pediatric Surgery during the period of four years (January 2018 to December 2021), and all children between 1 month and 12 years of age who were admitted for routine surgery and were operated on were included. The goal was to assess the accuracy of Broselow pediatric emergency tape in predicting the size of ET and LMA in children and assess the applicability of this tape in an Indian setting based on observation and comparison with the predicted ET tube and LMA size based on the tape. The correlation was done between the predicted ET tube and LMA size and used ET tube and LMA size (the difference and mean). The Chi-square test was applied to test the difference between those matching and those not matching with their respective color zones with respect to weight, tracheal tube (LMA/ET) tube, and for both weight and tracheal tube, and then the p-value was calculated. A p-value of less than 0.05 was considered to be significant. Results A total of 296 patients were included in the study. There were 230 males and 66 females. A maximum number of patients were in the white zone (56 patients). A total of 112 patients (37.8%) matched the zone with their weight; 192 patients (64.8%) matched their LMA/ET tube with their respective zones; 81 patients (27.36%) matched both their weights and tracheal tube (LMA/ET) size with the predicted values as per their respective zones. Pearson's Chi-square test was applied to assess the significance of the difference between the number of patients matching and not matching their weight, LMA/ET tube, and both weight and LMA/ET tube with their corresponding color zones as per the Broselow tape. For all the above parameters, the differences were found to be not significant for p-value <0.05. Conclusions Broselow tape (BT) is applicable in acute trauma settings where it can be used for estimating weight and ET/LMA sizes in an emergency situation where weight measurement is not feasible.

Less Invasive Surfactant Administration (LISA) in Premature Neonates, using 5F feeding tube versus 2 mm Endotracheal tube – An Innovative, Pilot study

Introduction: Administration of LISA using thin and soft catheters like 5 F orogastric tube, though less invasive, is technically challenging and needs expertise. We hypothesized, use of a 2 mm Endotracheal (ET) tube for administration of LISA could be an easy and convenient alternative. Methods: This is a prospective, single-centric, quasi-random, pilot trial conducted in the inborn unit of a tertiary care hospital from May 2020 - December 2020. All the inborn preterm (28 - 34 weeks) neonates with respiratory distress requiring surfactant were alternately allocated to receive LISA using a 5 F infant feeding tube or an uncuffed 2.0 size ET tube. The primary outcome was successful administration of surfactant defined as a procedure without any need for positive pressure ventilation. Results: In our study, 25 neonates were enrolled in each arm. Administration of LISA using 2 mm ET tube was associated with better success of surfactant administration with lesser incidence of PPV (20 vs 11, p &lt; 0.05), desaturation (5 vs 12, p &lt; 0.05), and bradycardia (3 vs 10, p &lt; 0.05) compared to LISAOG. Conclusions: Administration of LISA using a 2 mm ET is an easily adaptable and convenient alternative that is well tolerated by the neonates without any adverse effects.

689: POST-EXTUBATION DYSPHAGIA IN CHILDREN AFTER MECHANICAL VENTILATORY SUPPORT

Introduction: Post-extubation dysphagia (PED) is prevalent among critically ill adult patients after mechanical ventilatory support and is associated with significant morbidity including aspiration pneumonia, alteration of feeding, malnutrition, decreased quality of life, prolonged hospitalization and mortality. Sparse studies exist detailing the prevalence, contributing risk factors and health-related outcomes of PED in critically ill children. Methods: Single-center, retrospective chart review of patients without a pre-existing dysphagia diagnosis admitted to the pediatric intensive care unit at Shands Children’s Hospital at University of Florida from June 2015 through June 2020. Patients with instrumental dysphagia evaluations after >24 hours of mechanical ventilatory support were included in the data analysis and categorized based on the presence of aspiration or dysphagia. This study aimed to determine PED prevalence, demographic and intubation risk factors contributing to PED, and the impact PED on health-related outcomes. Results: There were 36 patients included in the analysis (median age: 5 years). 72% of patients were emergently intubated (median number of attempts: 2; 86% with cuffed endotracheal tube) with a median duration of 11.5 days of mechanical ventilatory support. Aspiration was present in 64% (n=23) of the cohort. 92% (n=21) of patients with PED were silent aspirators. No demographic (age, weight, sex, pre-existing conditions) or intubation risk factors (intubation attempts, duration of mechanical ventilation, presence of cuffed endotracheal tube, endotracheal tube size) were significantly associated with the development of PED (p>0.05). Patients with PED were more likely to be re-intubated secondary to weakness or neuromuscular compromise (p=0.04). There was no significant association between PED and in-hospital mortality. However, PED was significantly associated with the need for home oxygen after discharge (p=0.03; OR 6.25; 95%CI 1.3-29.4), and modification of home feeds at both ICU (p=0.001; OR 15.0; 95% CI 2.8-81.4) and hospital discharge (p=0.001; OR 16.8; 95%CI 2.7-104.8). Conclusions: PED is prevalent and associated with worse-health related outcomes among critically ill children after mechanical ventilatory support.

Prevalence and Predictors of Post-Thyroidectomy Voice Dysfunction in a Nigerian Cohort.

Advances in surgical techniques have significantly improved the safety of thyroidectomy. Quality of life issues, such as voice changes, however continue to be important considerations. This study evaluated the prevalence and determinants of voice changes following thyroidectomies for non-malignant goiters in a Nigerian Hospital. Consecutive adults who had thyroidectomy for non-malignant goiters were evaluated. Preoperatively, each participant had laryngoscopy and voice assessment using the Voice Handicap Index-10. At surgery, the intubation difficulty score, size of endotracheal tubes, and duration of operation were recorded. Laryngoscopy and VHI-10 assessments were repeated 1week, 1month, and 3months after surgery. Pre and postoperative assessments were compared. Fifty-four patients completed the study. Subtotal thyroidectomy was the commonest operation performed in 17 patients (31.48%), with 14 (25.93%) having total thyroidectomy. Baseline median VHI-10 score was 6.5(IQR-10). Five patients had abnormal preoperative laryngoscopy findings (benign vocal cord lesions). Postoperatively, seven patients had endoscopic evidence of vocal cord paralysis, six were unilateral while one was bilateral. Ten patients (18.5%) had early voice changes. Median VHI-10 score at one week was significantly higher than baseline (10 vs. 6.5, p = 0.01). At 3months, VHI-10 reverted back to baseline in five of the ten patients while five patients (9.3%) had persistent voice changes. Abnormal endoscopic findings predicted the occurrence of early postoperative voice changes. Thyroidectomy for non-malignant goiters is associated with transient voice changes, many of which revert to normal over time. Abnormal endoscopic findings predict its occurrence.

Risk factors of arytenoid dislocation after endotracheal intubation: A propensity-matched analysis.

Arytenoid dislocation (AD) after general anesthesia with endotracheal intubation (EI) is an iatrogenic injury that impairs patient function and requires reduction. We aimed to investigate the risk factors of AD following EI. This retrospective case-control study involved surgical adults who received EI for general anesthesia at a single institution from June 2010 to June 2020. Cases included all the patients who had AD. We used a ratio of 1:5 to identify patients in the propensity-matched control group. Multivariate analysis of 49 cases with AD and 245 controls without AD demonstrated that the use of a nasogastric (NG) tube (odds ratio [OR], 23.9; 95% confidence interval [CI], 6.8-84.1), undergoing abdominal surgery (OR, 3.7; 95% CI, 1.2-11.9), and an operative time longer than 3h (OR, 5.2; 95% CI, 2.1-12.9) were risk factors for AD. We did not find significant independent associations between AD and 40 years or older age, gender, body mass index, whether a laryngeal mask airway was used, endotracheal tube size, and EI performers' experience. The use of an NG tube, abdominal surgery, and longer operative time were risk factors for AD. Among these, the NG tube application showed a strong association with AD. Preventive measures of informing the patients of the increased risk and providing high-level patient monitoring can reduce the incidence of AD. III.

Association Between Pressure Support During Extubation Readiness Testing and Time to First Extubation in Children With Congenital Heart Disease.

Extubation readiness testing (ERT) is often performed in children with congenital heart disease prior to liberation from mechanical ventilation. The ideal ERT method in this population is unknown. We recently changed our ERT method from variable (10, 8, or 6 cm H2O, depending on endotracheal tube size) to fixed (5 cm H2O) pressure support (PS). Our study assessed the association between this change and time to first extubation and need for re-intubation. We studied 2 temporally distinct cohorts, one where ERT was conducted with variable PS and another using PS fixed at 5 cm H2O. Data were prospectively collected as part of a quality improvement project. The primary outcome was time to first extubation. Secondary outcomes were need for re-intubation and percentage of successful ERTs. We performed Poisson regression or logistic regression for the association between PS during ERT and time to first extubation or re-intubation, respectively. We included 320 subjects, 186 in the variable PS group and 152 in fixed PS group. In unadjusted analysis, median time to first extubation was longer in the fixed PS group compared to the variable PS group (4.1 [2.0-7.1] d vs 3.1 [1.1-5.9] d, P = .02), and there was no difference in re-intubation rate (11% vs 8%, P = .34). Subjects in the fixed PS group were significantly more likely to be mechanically ventilated after cardiac arrest, have a Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) category of 4 or 5, be extubated on day shift, receive enteral feeds at extubation, have higher respiratory support at extubation, and higher dead-space-to-tidal-volume ratio. After controlling for these variables in multivariable regression, we found no association between the choice of PS and time to first extubation or re-intubation. The use of a fixed PS of 5 cm H2O instead of variable PS during ERT was not associated with longer time to first extubation or extubation failure.

Effect of endotracheal tube size on airway resistance and dynamic lung compliance.

There are different results on the effect of endotracheal tube (ETT) size on respiratory mechanics in patients undergoing mechanical ventilation, and there are few reports in adult laparoscopic surgery. The aim of this study was to investigate the effect of ETT size on airway resistance (RAW) and dynamic lung compliance (COMPL) in patients undergoing laparoscopic colorectal surgery. Seventy-two patients undergoing laparoscopic radical surgery for colorectal cancer under general anesthesia with endotracheal intubation were selected and divided into 3 groups (n = 24) using the random number table method Group A (ETT ID 7.0), Group B (ETT ID 7.5), and Group C (ETT ID 8.0). After mechanical ventilation, intraoperative RAW and COMPL were monitored in each of the 3 groups. In the non-pneumoperitoneal state, RAW in group ID7.0 is significantly higher than this in group ID7.5 and group ID8.0 (P < .05); the RAW between the 2 groups with ID7.5 and ID8.0 was not statistically significant (P > .05). The difference of COMPL between the 3 groups was statistically significant (P < .05); the COMPL of Group ID7.0 is lower than Group ID7.5, and Group ID7.5 is lower than Group ID8.0. In the pneumoperitoneal state, the RAW between ID7.0 group and ID8.0 group was statistically significant, the RAW difference between ID7.0 group and ID7.5 group, ID7.5 group and ID8.0 group not statistically significant (P > .05);the COMPL between the 3 groups was not statistically significant (P > .05). In the non-pneumoperitoneal state, the smaller the ETT internal diameter within a certain range, the higher RAW and the lower COMPL; in the pneumoperitoneal state, the RAW with the ID7.0 ETT was higher than that with the ID8.0 ETT, and the ETT size within a certain range had no effect on COMPL.

Choice of the correct size of endotracheal tube in pediatric patients.

Selection and insertion of an endotracheal tube (ETT) of appropriate size for airway management during general anesthesia in pediatric patients is very important. A very small ETT increases the risk of inadequate ventilation, air leakage, and aspiration, whereas a very large ETT may cause serious complications including airway damage, post-intubation croup, and, in severe cases, subglottic stenosis. Although the pediatric larynx is conical, the narrowest part, the rima glottidis, is cylindrical in the anteroposterior dimension, regardless of development, and the cricoid ring is slightly elliptical. A cuffed ETT reduces the number of endotracheal intubation attempts, and if cuff pressure can be maintained within a safe range, the risk of airway damage may not be greater than that of an ETT without cuff. The age-based formula suggested by Cole (age/4 + 4) has long been used to select the appropriate ETT size in children. Because age-based formulas in children are not always accurate, various alternative methods for estimating the ETT size have been examined and suggested. Chest radiography, ultrasound, and a three-dimensional airway model can be used to determine the appropriate ETT size; however, there are several limitations.