Effect of cuff inflation with lidocaine, saline, and air on tracheal tube cuff pressure during laparoscopic resection of colorectal neoplasms: a randomized clinical trial.

BACKGROUND: Tracheal tube cuff pressure will increase after pneumoperitoneum when the cuff is inflated with air, high pressure can cause tracheal mucosal damage. This prospective trial aimed to assess if inflating with normal saline or lidocaine can prevent increase of tracheal tube cuff pressure and tracheal mucosal damage in laparoscopic surgeries with general anesthesia. Whether changes of tracheal tube cuff transverse diameter (CD) can predict changes of tracheal tube cuff pressure. METHODS: Ninety patients scheduled for laparoscopic resection of colorectal neoplasms under general anesthesia were randomly assigned to groups air (A), saline (S) or lidocaine (L). Endotracheal tube cuff was inflated with room-temperature air in group A (n = 30), normal saline in group S (n = 30), 2% lidocaine hydrochloride injection in group L (n = 30). After intubation, tracheal tube cuff pressure was monitored by a calibrated pressure transducers, cuff pressure was adjusted to 25 cmH2O (T0.5). Tracheal tube cuff pressure at 15 min after pneumoperitoneum (T1) and 15 min after exsufflation (T2) were accessed. CD were measured by ultrasound at T0.5 and T1, the ability of ΔCD (T1-0.5) to predict cuff pressure was accessed. Tracheal mucous injury at the end of surgery were also recorded. RESULTS: Tracheal tube cuff pressure had no significant difference among the three groups at T1 and T2. ΔCD had prediction value (AUC: 0.92 [95% CI: 0.81-1.02]; sensitivity: 0.99; specificity: 0.82) for cuff pressure. Tracheal mucous injury at the end of surgery were 0 (0, 1.0) in group A, 0 (0, 1.0) in group S, 0 (0, 0) in group L (p = 0.02, group L was lower than group A and S, p = 0.03 and p = 0.04). CONCLUSIONS: Compared to inflation with air, normal saline and 2% lidocaine cannot ameliorate the increase of tracheal tube cuff pressure during the pneumoperitoneum period under general anesthesia, but lidocaine can decrease postoperative tracheal mucosa injury. ΔCD measured by ultrasound is a predictor for changes of tracheal tube cuff pressure. TRIAL REGISTRATION: Chinese Clinical Trial Registry, identifier: ChiCTR2100054089, Date: 08/12/2021.

Common double-lumen tube selection methods overestimate adequate tube sizes in individual patients - a 3D reconstruction study.

BACKGROUND: Appropriate selection of double-lumen tube sizes for one-lung ventilation is crucial to prevent airway damage. Current selection methods rely on demographic factors or 2D radiography. Prediction of left bronchial diameter is indispensable for choosing the adequate tube size. This prospective observational study investigates if current selection methods sufficiently predict individuals' left bronchial diameters for DLT selection compared to the 3D reconstruction. METHODS: 100 patients necessitating thoracic surgery with one-lung ventilation and left-sided double-lumen tubes, ≥ 18 years of age, and a set of chest X-rays and 2D thorax CT scans for 3D reconstruction of the left main bronchus were included between 07/2021 and 06/2023. The cross-validated prediction error and the width of the 95%-prediction intervals of the 3D left main bronchial diameter utilizing linear prediction models were based on current selection methods. RESULTS: The mean bronchial diameter in 3D reconstruction was 13.6 ± 2.1 mm. The ranges of the 95%-prediction intervals for the bronchial diameter were 6.4 mm for demographic variables, 8.3 mm for the tracheal diameter from the X-ray, and 5.9 mm for bronchial diameter from the 2D-CT scans. Current methods violated the suggested '≥1 mm' safety criterion in up to 7% (men) and 42% (women). Particularly, 2D radiography overestimated women's left bronchial diameter. Current methods even allowed the selection of double-lumen tubes with bronchial tube sections greater than the bronchial diameter in women. CONCLUSIONS: Neither demographic nor 2D-radiographic methods sufficiently account for the variability of the bronchial diameter. Wide 95%-prediction intervals for the bronchial diameter hamper accurate individual double-lumen tube selection. This increases women's risk of bronchial damage, particularly if they have other predisposing factors. These patients may benefit from 3D reconstruction of the left main bronchus. TRIAL REGISTRATION: Not applicable.

Risk factor evaluation of cuff pressure of >30 cmH2O to stop air leakage during mechanical ventilation: A prospective observational study.

AIM: The commonly recommended endotracheal tube cuff pressure is 20-30 cmH2O. However, some patients require a cuff pressure of >30 cmH2O to prevent air leakage. The study aims to determine the risk factors that contribute to the endotracheal tube cuff pressure of >30 cmH2O to prevent air leakage. DESIGN: A multi-centre prospective observational study. METHODS: Eligible patients undergoing mechanical ventilation in the intensive care unit of three hospitals between March 2020 and July 2022 were included. The endotracheal tube cuff pressure to prevent air leakage was determined using the minimal occlusive volume technique. The patient demographics and clinical information were collected. RESULTS: A total of 284 patients were included. Among these patients, 55 (19.37%) patients required a cuff pressure of >30 cmH2O to prevent air leakage. The multivariate logistic regression results revealed that the surgical operation (odds ratio [OR]: 8.485, 95% confidence interval [CI]: 1.066-67.525, p = 0.043) was inversely associated with the endotracheal tube cuff pressure of >30 cmH2O, while the oral intubation route (OR: 0.127, 95% CI: 0.022-0.750, p = 0.023) and cuff inner diameter minus tracheal area (OR: 0.949, 95% CI: 0.933-0.966, p < 0.001) were negatively associated with the endotracheal tube cuff pressure of >30 cmH2O. Therefore, a significant number of patients require an endotracheal tube cuff pressure of ＞30 cmH2O to prevent air leakage. Several factors, including the surgical operation, intubation route, and difference between the cuff inner diameter and tracheal area at the T3 vertebra, should be considered when determining the appropriate cuff pressure during mechanical ventilation.

Novel method of attaching a suction tube externally to a tracheal tube as an insertion route for a Fogarty catheter in cryobiopsy: Retrospective comparative study.

BACKGROUND: Cryobiopsy use is anticipated to become more common in diagnosing lung diseases. In Japan, inserting a Fogarty catheter through a suction channel above the endotracheal tube's cuff for hemostasis is common practice. However, the rigid nature of the endotracheal tube poses challenges to tracheal intubation using a bronchoscope. The endotracheal tube cuff must be removed to prevent interference during Fogarty catheter insertion. To simplify the procedure and enhance safety, we devised and implemented a method of inserting a hemostatic Fogarty catheter with a suction tube externally attached to a softer endotracheal tube. This study aimed to evaluate the sustainability of this Fogarty catheter insertion method using suction tubes. METHODS: The hemostatic Fogarty catheter insertion method was retrospectively validated. We compared outcomes between 60 patients who underwent the conventional method with a suction channel above the cuff and 50 patients who underwent the novel approach with an externally attached suction tube. RESULTS: The physicians performing bronchoscopy and inserting the Fogarty catheter in the group in which the suction tube was externally attached for Fogarty catheter insertion had little experience. However, the overall bronchoscopy time was shorter; the two groups showed no significant differences in complications. CONCLUSION: Regarding cryobiopsy procedures, using an externally attached suction tube for Fogarty catheter insertion was practical and comparable to the conventional method of using a suction channel above the cuff. This method made the procedure more simple and safe.

Effect of varying cuff sizes with identical inner diameter on endotracheal intubation in critically ill adults: A sealed tracheal controlled trial.

BACKGROUND: The present study aims to determine the impact of different cuff diameters on the cuff pressure of endotracheal tubes (ETTs) when the trachea is adequately sealed. METHODS: In the present single-center clinical trial, adult patients who underwent cardiothoracic surgery were assigned to use ETTs from 2 brands (GME and GZW). The primary endpoint comprised of the following: cuff diameter, inner diameter of the ETT, manufacturer, and the number of subjects with tracheal leakage when the cuff pressure was 30 cm H2O. RESULTS: A total of 298 patients were assigned into 2 groups, based on the 2 distinct brands of ETTs: experimental group (n = 122, GME brand) and control group (n = 176, GZW brand). There were no significant differences in baseline characteristics. However, the cuff diameter was significantly smaller in the control group, when compared to the experimental group (P = .001), and the incidence of tracheal leakage was significantly higher in the control group (P = .001). Furthermore, the GME brand ETT had a significantly larger cuff diameter, when compared to the GZW brand ETT. CONCLUSION: The cuff size would mismatch the tracheal area in clinical practice. Therefore, chest computed tomography is recommended to routinely evaluate the tracheal cross-sectional area during anesthesia, in order to ensure the appropriate cuff size selection.

Effect of a 3D-printed reconstruction automated matching system for selecting the size of a left double-lumen tube: a study protocol for a prospective randomised controlled trial.

INTRODUCTION: Lung isolation is primarily accomplished using a double-lumen tube (DLT) or bronchial blocker. A precise and accurate size of the DLT is a prerequisite for ensuring its accurate placement. Three-dimensional (3D) reconstruction technology can be used to accurately reproduce tracheobronchial structures to improve the accuracy of DLT size selection. Therefore, we have developed automatic comparison software for 3D reconstruction based on CT data (3DRACS). In this study, we aimed to evaluate the efficiency of using 3DRACS to select the DLT size for endobronchial intubation in comparison with using the 'blind' DLT intubation method to determine the DLT size, which is based on height and sex. METHODS AND ANALYSIS: This is a prospective, single-centre, double-blind randomised controlled trial. In total, 200 patients scheduled for lung resection using a left DLT will be randomly allocated to the 3D group or the control group at a 1:1 ratio. A 3DRACS will be used for the 3D group to determine the size of the DLT, while in the case of the control group, the size of the DLT will be determined according to patient height and sex. The primary outcome is the success rate of placement of the left DLT without fibreoptic bronchoscopy (FOB). The secondary outcomes include the following: successful intubation time, degree of pulmonary atrophy, grade of airway injury, oxygenation during one-lung ventilation, postoperative sore throat and hoarseness, and number of times FOB is used. ETHICS AND DISSEMINATION: Ethical approval has been obtained from our local ethics committee (approval number: SCCHEC-02-2022-155). Written informed consent will be obtained from all participants before randomisation, providing them with clear instructions about the purpose of the study. The results will be disseminated through peer-reviewed publications and conferences. TRIAL REGISTRATION NUMBER: NCT06258954.

Video versus Direct Laryngoscopy for Urgent Intubation of Newborn Infants.

BACKGROUND: Repeated attempts at endotracheal intubation are associated with increased adverse events in neonates. When clinicians view the airway directly with a laryngoscope, fewer than half of first attempts are successful. The use of a video laryngoscope, which has a camera at the tip of the blade that displays a view of the airway on a screen, has been associated with a greater percentage of successful intubations on the first attempt than the use of direct laryngoscopy in adults and children. The effect of video laryngoscopy among neonates is uncertain. METHODS: In this single-center trial, we randomly assigned neonates of any gestational age who were undergoing intubation in the delivery room or neonatal intensive care unit (NICU) to the video-laryngoscopy group or the direct-laryngoscopy group. Randomization was stratified according to gestational age (<32 weeks or ≥32 weeks). The primary outcome was successful intubation on the first attempt, as determined by exhaled carbon dioxide detection. RESULTS: Data were analyzed for 214 of the 226 neonates who were enrolled in the trial, 63 (29%) of whom were intubated in the delivery room and 151 (71%) in the NICU. Successful intubation on the first attempt occurred in 79 of the 107 patients (74%; 95% confidence interval [CI], 66 to 82) in the video-laryngoscopy group and in 48 of the 107 patients (45%; 95% CI, 35 to 54) in the direct-laryngoscopy group (P<0.001). The median number of attempts to achieve successful intubation was 1 (95% CI, 1 to 1) in the video-laryngoscopy group and 2 (95% CI, 1 to 2) in the direct-laryngoscopy group. The median lowest oxygen saturation during intubation was 74% (95% CI, 65 to 78) in the video-laryngoscopy group and 68% (95% CI, 62 to 74) in the direct-laryngoscopy group; the lowest heart rate was 153 beats per minute (95% CI, 148 to 158) and 148 (95% CI, 140 to 156), respectively. CONCLUSIONS: Among neonates undergoing urgent endotracheal intubation, video laryngoscopy resulted in a greater number of successful intubations on the first attempt than direct laryngoscopy. (Funded by the National Maternity Hospital Foundation; VODE ClinicalTrials.gov number, NCT04994652.).

Effects of saline submersion at body temperature on airway supportive devices including a novel nasopharyngeal device produced using 3D-printing.

PURPOSE: This study investigated dimension changes of various nasopharyngeal airways, including a novel self-supporting device, after saline submersion at body temperature to simulate in-vivo use. Dimension changes over time may reduce efficacy during long-term use and require sizing adjustments or limits on duration of use. MATERIALS AND METHODS: Cuffless Covidien endotracheal tubes, pediatric Rusch fixed flange polyvinyl chloride nasal airway tubes, pediatric Rusch Robertazzi style Mediprene nasal airway tubes, and novel silicone elastomer self-supporting nasopharyngeal airways were fully submerged in 0.9 % normal saline solution incubated at 37 degrees Celsius for 15 days. All devices had tube length and wall thickness measured after 0, 1, 2, 3, 4, 5, 10, and 15 days. The 95 % confidence intervals of tube dimensions at each date were compared with the 95 % confidence intervals at day 0. RESULTS: The Covidien ET tube, Rusch PVC NPA, and ssNPA tube lengths and wall thicknesses did not change significantly over 15 days. The Rusch Mediprene NPAs had a statistically significant increase in length starting at day 1 and wall thickness at day 2. CONCLUSIONS: The novel ssNPA did not expand in the in-vitro environment, supporting its safety for extended use. The PVC NPA and ET tube dimensions also remained stable. However, the Rusch Mediprene NPAs had significant length expansion after 1 day of submersion, indicating a considerable risk of expansion during extended use with potential implications for patient care. Silicone and PVC NPA dimensions remained stable when saturated, indicating these materials may be more appropriate for extended use.

Effect of different lung recruitment strategies and airway device on oscillatory mechanics in children under general anaesthesia.

BACKGROUND: Atelectasis has been reported in 68 to 100% of children undergoing general anaesthesia, a phenomenon that persists into the recovery period. Children receiving recruitment manoeuvres have less atelectasis and fewer episodes of oxygen desaturation during emergence. The optimal type of recruitment manoeuvre is unclear and may be influenced by the airway device chosen. OBJECTIVE: We aimed to investigate the different effects on lung mechanics as assessed by the forced oscillation technique (FOT) utilising different recruitment strategies: repeated inflations vs. one sustained inflation and different airway devices, a supraglottic airway device vs. a cuffed tracheal tube. DESIGN: Pragmatic enrolment with randomisation to the recruitment strategy. SETTING: We conducted this single-centre trial between February 2020 and March 2022. PARTICIPANTS: Seventy healthy patients (53 boys) aged between 2 and 16 years undergoing general anaesthesia were included. INTERVENTIONS: Forced oscillations (5 Hz) were superimposed on the ventilator waveform using a customised system connected to the anaesthesia machine. Pressure and flow were measured at the inlet of the airway device and used to compute respiratory system resistance and reactance. Measurements were taken before and after recruitment, and again at the end of surgery. MAIN OUTCOME MEASURES: The primary endpoint measured is the change in respiratory reactance. RESULTS: Statistical analysis (linear model with recruitment strategy and airway device as factors) did not show any significant difference in resistance and reactance between before and after recruitment. Baseline reactance was the strongest predictor for a change in reactance after recruitment: prerecruitment Xrs decreased by mean (standard error) of 0.25 (0.068) cmH 2 O s l -1 per  1 cmH 2 O -1  s l -1 increase in baseline Xrs ( P  < 0.001). After correcting for baseline reactance, the change in reactance after recruitment was significantly lower for sustained inflation compared with repeated inflation by mean (standard error) 0.25 (0.101) cmH 2 O ( P  = 0.0166). CONCLUSION: Although there was no significant difference between airway devices, this study demonstrated more effective recruitment via repeated inflations than sustained inflation in anaesthetised children. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: ACTRN12619001434189.

Comparison of i-gel® and LMA® Supreme™ for Facilitating Fiberoptic Endotracheal Intubation: A Prospective Randomized Trial.

Supraglottic airway (SGA) is an alternative to endotracheal intubation, however endotracheal intubation is often essential. One method to convert from an SGA to an endotracheal tube (ETT) is utilizing the SGA as a conduit for fiberoptic-guided advancement of an Aintree catheter (airway exchange catheter), and exchange of the SGA for an ETT. In this prospective randomized study, we compared two SGA devices in facilitating this exchange. Subjects were randomized to receive either the i-gel® or LMA® Supreme™ SGA. The SGA was placed and an Aintree intubation catheter was inserted through the SGA over a fiberoptic bronchoscope. Next, the SGA was removed, leaving the Aintree within the trachea, and an ETT was placed over the Aintree catheter and advanced into the trachea. The i-gel group exhibited shorter time to successful intubation (median, 191 vs. 434 seconds; P = .002). The i-gel group also had fewer study subjects requiring more than one attempt for successful Aintree placement (33% vs. 75%, P = .02). The i-gel group showed superior laryngeal view score (LVS) (6 vs. 4; P = .003). The i-gel SGA achieved a faster time to successful intubation, higher rate of first attempt Aintree placement, and superior LVS.

Curious Case of Pediatric One-Lung Ventilation with Two Endotracheal Tubes: A Case Report.

ABSTRACT: One-lung ventilation is indicated during thoracic surgery for visualization and exposure of surgical site. It is achieved with bronchial blockers, double-lumen endobronchial tube, single-lumen endotracheal tubes and Univent tube for infants and children. Fibreoptic bronchoscope is required for placing and confirming the correct position of these tubes. We report a perioperative management of safe conduct of one lung ventilation for a 6-year child undergoing left lower lobe lobectomy through C-MAC video laryngoscope guided two single lumen tubes in limited resource settings where paediatric-sized fibreoptic bronchoscope is unavailable.

A randomised controlled trial to compare blind intubation success through LMA Blockbuster® and I-Gel® LMA.

INTRODUCTION: Laryngeal mask airway-blockbuster (LMA-BT) is a relatively new supraglottic airway device (SGAD). In this study, we compared LMA-BT with I-Gel LMA for efficacy of blind tracheal intubation. MATERIAL AND METHODS: We conducted a single-blind prospective study after ethical approval. One hundred American Society of Anesthesiology (ASA) Grade I-III (age 18-60 years) patients scheduled for elective surgery under general anaesthesia with endotracheal intubation were included and randomly divided into 2 groups. Blind tracheal intubation was performed through LMA-BT ( n = 50) and I-Gel ( n = 50) in groups 1 and 2, respectively. The primary aim was to evaluate the first pass success rate of blind tracheal intubation through the LMAs. The secondary objectives noted were attempts and ease of LMA insertion, total time taken for LMA insertion, airway seal pressure of LMA, ease of NGT insertion through LMA, fibre-optic grading of laryngeal view through LMA, overall success rate and time of intubation through LMA, time for LMA removal, and complications, if any. RESULTS: In the LMA-BT group, the first pass success rate ( P < 0.019) and the overall success rate of intubation ( P < 0.005) were significantly higher than in the I-Gel group. Using LMA-BT also resulted in statistically significant shorter intubation time ( P < 0.0001) with higher airway seal pressure as compared to I-Gel ( P < 0.001). The difference in the first attempt insertion, number of insertion attempts, ease and time of LMA insertion and removal after intubation, and postoperative complications were comparable among the groups. CONCLUSIONS: LMA-BT is a superior device as compared to I-Gel LMA as a conduit for blind tracheal intubation.

Efficacy of bougie first approach for endotracheal intubation with video laryngoscopy during continuous chest compression: a randomized crossover manikin trial.

BACKGROUND: Endotracheal intubation is challenging during cardiopulmonary resuscitation, and video laryngoscopy has showed benefits for this procedure. The aim of this study was to compare the effectiveness of various intubation approaches, including the bougie first, preloaded bougie, endotracheal tube (ETT) with stylet, and ETT without stylet, on first-attempt success using video laryngoscopy during chest compression. METHODS: This was a randomized crossover trial conducted in a general tertiary teaching hospital. We included anesthesia residents in postgraduate year one to three who passed the screening test. Each resident performed intubation with video laryngoscopy using the four approaches in a randomized sequence on an adult manikin during continuous chest compression. The primary outcome was the first-attempt success defined as starting ventilation within a one minute. RESULTS: A total of 260 endotracheal intubations conducted by 65 residents were randomized and analyzed with 65 procedures in each group. First-attempt success occurred in 64 (98.5%), 57 (87.7%), 56 (86.2%), and 46 (70.8%) intubations in the bougie-first, preloaded bougie, ETT with stylet, and ETT without stylet approaches, respectively. The bougie-first approach had a significantly higher possibility of first-attempt success than the preloaded bougie approach [risk ratio (RR) 8.00, 95% confidence interval (CI) 1.03 to 62.16, P = 0.047], the ETT with stylet approach (RR 9.00, 95% CI 1.17 to 69.02, P = 0.035), and the ETT without stylet approach (RR 19.00, 95% CI 2.62 to 137.79, P = 0.004) in the generalized estimating equation logistic model accounting for clustering of intubations operated by the same resident. In addition, the bougie first approach did not result in prolonged intubation or increased self-reported difficulty among the study participants. CONCLUSIONS: The bougie first approach with video laryngoscopy had the highest possibility of first-attempt success during chest compression. These results helped inform the intubation approach during CPR. However, further studies in an actual clinical environment are warranted to validate these findings. TRIAL REGISTRATION: Clinicaltrials.gov; identifier: NCT05689125; date: January 18, 2023.