Individualized rotation of left double lumen endobronchial tube to improve placement success rate: a randomized controlled trial.

BACKGROUND: In conventional practice, the left double lumen tube (DLT) is rotated 90° counterclockwise when the endobronchial cuff passes glottis. Success rate upon the first attempt is < 80%, likely owing to varying morphology of the bronchial bifurcation. METHODS: We conducted a randomized controlled trial to compare 90° counterclockwise rotation versus individualized degree of rotation in adult patients undergoing elective thoracic surgery using left DLT. The degree of rotation in the individualized group was based on the angle of the left main bronchi as measured on computed tomography (CT). The primary outcome was the first attempt left DLT placement success rate. RESULTS: A total of 556 patients were enrolled: 276 in the control group and 280 in the individualized group. The average angle of the left main bronchi was 100.6±9.5° (range 72° to 119°). The first attempt left DLT placement success rate was 82.6% (228/276) in the control group versus 91.4% (256/280) in the individualized group (P=0.02, χ2 test). The rate of carina mucosal injury, as measured at 30 min after the start of surgery under fibreoptic bronchoscopy, was significantly lower in individualized group than control group (14.0% versus 19.6%, P=0.041). The individualized group also had lower rate of postoperative sore throat (29.4% versus 44.0%, P<0.001) and hoarseness (16.8% versus 24.7%, P＜0.05). CONCLUSIONS: Individualized rotation of left DLT based on the angle of the left main bronchi on preoperative CT increased first attempt success rate in adult patients undergoing elective thoracic surgery. TRIAL REGISTRATION: The trial is registered at Chinese Clinical Trial Registry (ChiCTR2100053349; principal investigator Xiang Quan, date of registration November 19, 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.

Cardiopulmonary crisis caused by bronchial blocker malposition in a patient with aberrant tracheal anatomy: a case report.

BACKGROUND: Double-lumen tubes (DLTs) and bronchial blockers (BBs) can be used to establish one-lung ventilation (OLV) for thoracic surgery. BBs are a good alternative when DLTs are not suitable or patients have difficult airways. However, BBs are more prone to malposition, leading to adverse events. CASE PRESENTATION: We present a 68-year-old male patient who was scheduled for thoracoscopic left lower lobectomy. The patient was not expected to have airway malformation preoperatively. When the DLT could not be inserted into the bronchus after general anesthesia induction, we used a BB to perform OLV. During surgery, malposition of the BB resulted in the development of an "incomplete balloon valve", leading to a cardiopulmonary crisis. CONCLUSIONS: Previewing chest computed tomography scans to assess the airway anatomy before thoracic surgery is essential. Three-dimensional reconstruction of the airway can provide a more intuitive assessment of airway anatomy. During OLV with BBs, we should pay attention to balloon malposition to prevent cardiopulmonary crises.

Efficacy and safety of video double-lumen tube intubation in lateral position in patients undergoing thoracic surgery: a randomized controlled trial.

BACKGROUND: Video double-lumen tube (VDLT) intubation in lateral position is a potential alternative to intubation in supine position in patients undergoing thoracic surgery. This non-inferiority trial assessed the efficacy and safety of VDLT intubation in lateral position. METHODS: Patients (18-70 yr) undergoing right thoracoscopic lung surgery were randomized to either the left lateral position group (group L) or the supine position group (group S). The VDLT was placed under video larygoscopy. The primary endpoint was the intubation time. Secondary endpoints included VDLT displacement rate, intubation failure rate, the satisfaction of surgeon and nurse, and intubation-related adverse events. RESULTS: The analysis covered 80 patients. The total intubation time was 52.0 [20.4]s in group L and 34.3 [13.2]s in group S, with a mean difference of 17.6 s [95% confidence interval (CI): 9.9 s to 25.3 s; P = 0.050], failing to demonstrate non-inferiority with a non-inferiority margin of 10 s. Group L, compared with group S, had significantly lower VDLT displacement rate (P = 0.017) and higher nurse satisfaction (P = 0.026). No intubation failure occurred in any group. Intubation complications (P = 0.802) and surgeon satisfaction (P = 0.415) were comparable between two groups. CONCLUSIONS: The lateral VDLT intubation took longer time than in the supine position, and non-inferiority was not achieved. The incidence of displacement as the secondary endpoint was lower in the L group, possibly due to changing body positions beforehand. The indication of lateral VDLT intubation should be based on a balance between the safety of airway management and the lower incidence of displacement. TRIAL REGISTRATION: The study was registered at Chictr.org.cn with the number ChiCTR2200064831 on 19/10/2022.

Double lumen endobronchial tube intubation: lessons learned from anatomy.

BACKGROUND: Double lumen endobronchial tubes (DLTs) are frequently used to employ single lung ventilation strategies during thoracic surgical procedures. Placement of these tubes can be challenging even for experienced clinicians. We hypothesized that airway anatomy, particularly of the glottis and proximal trachea, significantly impacts the ease or difficulty in placement of these tubes. METHODS: Images from 24 randomly selected Positron Emission Tomography - Computed Tomography (PET-CT) scans were evaluated for several anatomic aspects of the upper airway, including size and angulation of the glottis and proximal tracheal using calibrated CT measurements and an online digital protractor. The anatomic issues identified were confirmed in cadaveric anatomic models. RESULTS: Proximal tracheal diameter measurements in PET-CT scans demonstrated a mean ± standard deviation of 20.4 ± 2.5 mm in 12 males and 15.5 ± 0.98 mm in 12 females (p < 0.001), and both were large enough to accommodate 39 French and 37 French DLTs in males and females, respectively. Subsequent measurements of the posterior angulation of the proximal trachea revealed a mean angle of 40.8 ± 5.7 degrees with no sex differences. By combining the 24 individual posterior tracheal angles with the 16 angled distal tip measurements DLTs (mean angle 24.9 ± 2.1 degrees), we created a series of 384 patient intubation angle scenarios. This data clearly showed that DLT rotation to a full 180 degrees decreased the mean intubation angle between the DLT and the proximal trachea from a mean of 66.6 ± 5.9 to only 15.8 ± 5.9 degrees. CONCLUSIONS: Rotation of DLTs a full 180 instead of the recommended 90 degrees facilitates DLT intubations.

A novel combined approach to placement of a double lumen endobronchial tube using a video laryngoscope and fiberoptic bronchoscope: a retrospective chart review.

BACKGROUND: The objective of this study was to evaluate a modern combined video laryngoscopy and flexible fiberoptic bronchoscope approach to placement of a double lumen endobronchial tube and further characterize potential strengths and weaknesses of this approach. METHODS: Retrospective chart review was conducted at our single institution, academic medical center, tertiary-care hospital. Patients aged 18 years of age or older were evaluated who underwent thoracic surgery and one-lung ventilation with placement of a double lumen endobronchial tube using a novel combined video laryngoscopy and flexible fiberoptic bronchoscope approach. No interventions were performed. RESULTS: Demographics and induction and intubation documentation were reviewed for 21 patients who underwent thoracic surgery and one-lung ventilation with placement of a double lumen endobronchial tube using a novel combined video laryngoscopy and flexible fiberoptic bronchoscope approach. First pass success using the combined approach was 86% (18/21). The five patients with an anticipated difficult airway had successful double lumen endobronchial tube placement on the first attempt. There were no instances of desaturation during double lumen endobronchial tube placement. No airway complications related to double lumen endobronchial tube placement were recorded. CONCLUSION: Use of a combined approach employing video laryngoscopy and a flexible fiberoptic bronchoscope may represent a reliable alternative approach to placement of double lumen endobronchial tubes.

Facilitating Lung Collapse for Thoracoscopic Surgery Utilizing Endobronchial Airway Occlusion Preceded by Pleurotomy and One-minute Suspension of Two-lung Ventilation.

OBJECTIVES: To assess when and whether clamping the double-lumen endobronchial tube (DLT) limb of the non-ventilated lung is more conducive to a rapid and effective lung deflation than simply allowing the open limb of the DLT to communicate with the atmosphere. DESIGN: This was a single-center, single-blind, randomized, controlled trial. SETTING: The trial was performed in a single institutional setting. PARTICIPANTS: The participants were 60 patients undergoing elective video-assisted thoracoscopic surgery. INTERVENTIONS: Patients were randomized to the open-clamp airway technique (OCAT group) or control group. Patients in the control group had one-lung ventilation initiated upon being placed in the lateral decubitus position. The OCAT group had two-lung ventilation maintained until the pleural cavity was opened with the introduction of a planned thoracoscopic access port to allow the operated lung to fall away from the chest wall. Thereafter, ventilation was suspended (temporarily ceased) for 1 minute before the DLT lumen of the isolated lung was clamped. The primary outcome of the trial was the time to complete lung collapse scored as determined from video clips taken during surgery. The secondary outcomes were (1) lung collapse score at 30 minutes after pleural incision, (2) surgeon satisfaction with surgery, and (3) intraoperative hypoxemia. MEASUREMENTS AND MAIN RESULTS: The median time to reach complete lung collapse in the OCAT group was 10 minutes (odds ratio 10.0, 95% CI 6.3-13.7), which was much shorter than that of the control group (25 minutes [odds ratio 25.0, 95% CI 13.6-36.4]). The difference in complete lung collapse at 30 minutes between the 2 groups was significant (p < 0.001). The surgeon's satisfaction with surgery was higher in the OCAT group than in the control group (8.5 ± 0.2 vs 6.8 ± 0.2; p < 0.001). There was no difference regarding intraoperative hypoxemia. CONCLUSIONS: Suspending ventilation of both DLT limbs for 1 minute after pleural cavity opening and then clamping the DLT lumen of the isolated lung resulted in a more rapid deflation of the surgical lung. This open-clamp airway technique is an effective technique for rapid surgical lung collapse during thoracoscopic surgery.

[Comparison of Two Methods With a Left-Sided Double-Lumen Tube for Endobronchial Intubation].

Objective To compare the success rates of two methods for endobronchial intubation:the left-sided double-lumen tube(DLT) rotated 90° counter-clockwise with the patient head at the mid positon and the tube rotated 180° counter-clockwise with the patient head turned to the right. Methods Six hundred and forty-eight patients were enrolled in this study,who were to undergo elective thoracic surgery by left-sided DLT intubation in the Peking Union Medical College Hospital from December 2021 to June 2022.They were randomized into a 90° group and a 180° group,with 324 patients in each group.In the 90° group,with the patient head kept at the mid position,the left-sided DLT was advanced until the bronchial cuff passed the vocal cords and then rotated 90° counter-clockwise.In the 180°group,with the left mandible angle of each patient in the straight line with the sternum,the tube was advanced until the bronchial cuff passed the vocal cords and then rotated 180° counter-clockwise.The intubation success rate and the intubation-related complications such as carina mucosal injuries were compared between the two groups. Results The 648 patients included 336 males and 312 females,with the age ranging from 39.0 to 75.0 years old and the average age of(54.6±9.0) years old.The success rate of first intubation was 80.3% in the 90° group and 75.0% in the 180° group,which showed no significant difference(P=0.109).The success rate of second intubation was higher in the 180° group than in the 90° group(P<0.001).The rate of carina mucosal injuries was 23.8% in the 90° group and 25.6% in the 180° group,which showed no significant difference(P=0.585). Conclusions Compared with the conventional method(90°),the intubation of the left-sided DLT rotated 180° counter-clockwise with the patient head turned to the right cannot improve the success rate of the first intubation.However,it could improve the success rate of reintubation as a remedy.

Follicular flushing increases the number of oocytes retrieved: a randomized controlled trial.

STUDY QUESTION: Does follicular flushing increase the number of cumulus-oocyte complexes (COCs) retrieved compared to single aspiration? SUMMARY ANSWER: Follicular flushing significantly increases the number of COCs retrieved compared to single aspiration. WHAT IS KNOWN ALREADY: On the basis of published meta-analyses, follicular flushing does not seem to increase the number of oocytes retrieved, the probability of clinical pregnancy, or that of live birth and has been associated with an increase in the duration of oocyte retrieval. It should be noted, however, that all the eligible randomized controlled trials (RCTs) in these meta-analyses have randomized patients into either single aspiration or follicular flushing. This study design might not allow the detection of the true effect of follicular flushing. Despite randomization, this might still be obscured, to an extent, by heterogeneity in patients, stimulation characteristics, and differences in the oocyte retrieval procedure. STUDY DESIGN, SIZE, DURATION: A prospective, single centre, RCT, including 105 patients was performed between July and December 2022. PARTICIPANTS/MATERIALS, SETTING, METHODS: Eligible patients were those undergoing oocyte retrieval for ICSI, aged <43 years, with BMI 18-35 kg/m2. Patients with all types of ovarian response (low-normal-high), as assessed on the day of triggering final oocyte maturation, were included. Random allocation of the ovaries of each patient to either single aspiration or follicular flushing was performed on the day of oocyte retrieval, using a computer-generated randomization list. Patients could enter the study only once. All follicles from ovaries allocated to either follicular flushing or single aspiration, were aspirated by the same 16G double lumen needle, with a constant aspiration pressure of 190 mmHg, resulting in flow rate of 0.42 ml/s. In the ovaries allocated to the follicular flushing group, if a COC was not recovered in the initial aspirate of each follicle, follicular flushing was performed until a COC was retrieved, up to a maximum of five times. The primary outcome measure was the number of COCs retrieved. Secondary outcomes were oocyte recovery rate, oocyte maturation rate, fertilization rate, and rate of good quality embryos on Day 2. Values are expressed as a median (inter-quartile range). MAIN RESULTS AND THE ROLE OF CHANCE: Significantly more COCs were retrieved in the follicular flushing as compared to the single aspiration group in all patients [5 (7) vs 2 (3), P < 0.001, respectively], as well as in patients with high [9 (3) vs 5 (4), P < 0.001, respectively], normal [5 (2) vs 2 (3), P < 0.001, respectively] and low [1 (1) vs 1 (1), P < 0.001, respectively] ovarian response. In patients with low ovarian response, no COCs were retrieved in 5.7% of the ovaries in the flushing group vs 42.8% of the ovaries in the single aspiration group (P < 0.001). The oocyte retrieval rate was significantly higher in the follicular flushing vs the single aspiration group, in all patients [88.9% (25.0) vs 45.5% (37.5), P < 0.001, respectively], as well as in patients with high [81.8% (15.9) vs 45.5% (22.2), P < 0.001, respectively], normal [85.7% (28.6) vs 40.0% (30.0), P < 0.001, respectively], and low [100% (0) vs 50.0% (100), P < 0.001, respectively] ovarian response. No significant difference was observed regarding maturation rate [85.2% (30.8) vs 100% (33.3), P = 0.78], fertilization rate [76.4% (50) vs 83.3% (50) P = 0.42], and the proportion of good quality embryos on Day 2 [83.3% (40) vs 100% (50), P = 0.62]. Similarly, no differences in the above variables were observed in patients with different types of ovarian response. Follicular flushing as compared to single aspiration was associated with a significant increase in the duration of oocyte retrieval in all patients [248 s (332) vs 135 s (164), respectively], as well as in patients with high [464 s (225) vs 237 s (89), P < 0.001, respectively], normal [248 s (108) vs 141 s (95), P < 0.001, respectively], and low [64 s (59) vs 48 s (10), P < 0.001, respectively] ovarian response. LIMITATIONS, REASONS FOR CAUTION: Although the current study design allows for a more accurate evaluation of the true effect of follicular flushing on the number of COCs retrieved, it does not permit the evaluation of its role on the probability of pregnancy. WIDER IMPLICATIONS OF THE FINDINGS: This is the first RCT to suggest that follicular flushing increases the number of COCs retrieved compared to single aspiration, independently of ovarian response. This implies that follicular flushing plays an important role in the optimization of oocyte retrieval. These results, however, need to be confirmed in future studies, in which an equal flow rate should be used during oocyte retrieval. STUDY FUNDING/COMPETING INTEREST(S): No external funding was obtained for this study. There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: NCT05473455. TRIAL REGISTRATION DATE: 15 July 2022. DATE OF FIRST PATIENT'S ENROLMENT: 27 July 2022.

Does follicular flushing increase oocyte number in poor responders? An update of a systematic review.

RESEARCH QUESTION: Does flushing of the follicles at ovum retrieval increase the number of retrieved oocytes in poor-response IVF patients? DESIGN: An update of an electronic literature search was performed to identify randomized controlled trials (RCT) investigating follicular flushing versus no flushing in women with a poor response to IVF treatment. No exclusion criteria for type of needle, stimulation or protocol were applied. A meta-analysis was conducted using the software RevMan 5.4. RESULTS: Six RCT were identified that had the primary objective of testing for an increase in mean number of cumulus-oocyte complexes or/and metaphase II oocytes between flushing and no flushing. A double-lumen needle was used in five trials, one study investigated a pseudo-double-lumen needle, and a conventional single-lumen needle was used in all the control groups. The main risk of bias in all the included studies is a lack of blinding of the physicians performing the puncture and incomplete data in four trials. A heterogeneity of direction and size of effect of follicular flushing on mean oocyte number retrieved was detected (I2 = 80, P = 0.0001), which precludes a synthesis of the data. Two studies showed a decrease or tendency towards a decrease in oocyte numbers, one study showed similar oocyte numbers, and one study showed a strong tendency towards increased oocyte numbers with flushing. A similar picture was seen for metaphase II oocytes (I2 = 73, P = 0.002). CONCLUSIONS: It is uncertain whether follicular flushing in poor-response IVF patients affects the number of retrieved oocytes. Larger pragmatic trials are warranted to clarify the effect of flushing on oocyte numbers and clinical outcomes in poor responders and monofollicular patients.

Effect of placing double-lumen irrigation-suction tube on closure of anastomotic defect following rectal cancer surgery.

PURPOSE: This study aimed to investigate the effect of placement of double-lumen irrigation-suction tubes (DLIST) on the closure of anastomotic defect (AD) after rectal cancer surgery. METHODS: The study was carried out at two centers managed by one surgeon, both adopted the same treatments. Patients with postoperative AD after rectal cancer surgery from January 2011 to June 2020 were eligible and were divided into a passive drainage (PD) group and a DLIST group according to whether the PD, placed in the rectal cancer surgery, had been replaced with the DLIST. The effect of DLIST on the AL was evaluated. RESULT: There distributed 76 patients in the DLIST group and 52 in the PD group. A higher closure rate was reported in the DLIST group (46 patients in DLIST group, for a closure rate of 60.5%, and 21 patients in PD group, for a closure rate of 40.4%. HR = 3.05; 95% CI: 1.79-5.19; P < 0.001). Both length of stay and costs of the treatment in the DLIST group were lower (54 days [interquartile range, IQR: 41-17] days vs. 112 days [IQR: 66-27] days, P = 0.005; and $18,721 [IQR: $14,982-4,960] vs. $40,840 [IQR: $20,932-50,529], P < 0.001). CONCLUSION: Placement of DLIST might serve as an effective method for treating AD following rectal cancer surgery. In comparison with PD, it costs lower to apply DLIST in the treatment of AD and the length of stay is shorter.

Quantification of exhaled propofol is not feasible during single-lung ventilation using double-lumen tubes: A multicenter prospective observational trial.

BACKGROUND: Volatile propofol can be measured in exhaled air and correlates to plasma concentrations with a time delay. However, the effect of single-lung ventilation on exhaled propofol is unclear. Therefore, our goal was to evaluate exhaled propofol concentrations during single-lung compared to double-lung ventilation using double-lumen tubes. METHODS: In a first step, we quantified adhesion of volatile propofol to the inner surface of double-lumen tubes during double- and single-lumen ventilation in vitro. In a second step, we enrolled 30 patients scheduled for lung surgery in two study centers. Anesthesia was provided with propofol and remifentanil. We utilized left-sided double-lumen tubes to separately ventilate each lung. Exhaled propofol concentrations were measured at 1-min intervals and plasma for propofol analyses was sampled every 20 min. To eliminate the influence of dosing on volatile propofol concentration, exhalation rate was normalized to plasma concentration. RESULTS: In-vitro ventilation of double-lumen tubes resulted in increasing propofol concentrations at the distal end of the tube over time. In vitro clamping the bronchial lumen led to an even more pronounced increase (Δ AUC +62%) in propofol gas concentration over time. Normalized propofol exhalation during lung surgery was 31% higher during single-lung compared to double-lung ventilation. CONCLUSION: During single-lung ventilation, propofol concentration in exhaled air, in contrast to our expectations, increased by approximately one third. However, this observation might not be affected by change in perfusion-ventilation during single-lung ventilation but rather arises from reduced propofol absorption on the inner surface area of the double-lumen tube. Thus, it is only possible to utilize exhaled propofol concentration to a limited extent during single-lung ventilation. REGISTRATION OF CLINICAL TRIAL: DRKS-ID DRKS00014788 (www.drks.de).

Airway management for a patient with tracheobronchomegaly undergoing lobectomy: a case report.

BACKGROUND: Tracheobronchomegaly (TBM) is a rare disorder mainly characterized by dilatation and malacia of the trachea and major bronchi with diverticularization. This will be a great challenge for airway management, especially in thoracic surgery requiring one-lung ventilation. Using a laryngeal mask airway and a modified double-lumen Foley catheter (DFC) as a "blocker" may achieve one-lung ventilation. This is the first report introducing this method in a patient with TBM. CASE PRESENTATION: We present a 64-year-old man with TBM receiving left lower lobectomy. Preoperative chest computed tomography demonstrated a prominent tracheobronchial dilation and deformation with multiple diverticularization. The most commonly used double-lumen tube or bronchial blocker could not match the distorted airways. After general anesthesia induction, a 4# laryngeal mask was inserted, through which the modified DFC was positioned in the left main bronchus with the guidance of a fiberoptic bronchoscope. The DFC balloon was inflated with 10 ml air and lung isolation was achieved without any significant air leak during one-lung or two-lung ventilation. However, the collapse of the non-dependent lung was delayed and finally achieved by low-pressure artificial pneumothorax. The surgery was successful and the patient was extubated soon after the surgery. CONCLUSIONS: Using a laryngeal mask airway with a modified double-lumen Foley catheter acted as a bronchial blocker could be an alternative method to achieve lung isolation.

Effect of pre-use of Dexmedetomidine on the effective inhibitory dose of remimazolam tosilate on positive cardiovascular response in double-lumen endobronchial intubation: a clinical study.

BACKGROUND: Herein, the effect of pre-use of Dexmedetomidine(Dex) on the half-effective dose (ED50) and 95%-effective dose (ED95) of Remimazolam tosilate(RT) in inhibiting the positive cardiovascular response(CR) which means blood pressure or heart rate rises above a critical threshold induced by double-lumen bronchial intubation was evaluated. METHODS: Patients who underwent video-assisted thoracic surgery were divided into groups A (0), B (0.5 µg/kg), and C (1 µg/kg) based on different Dex doses. Group A included subgroups comprising young (A-Y) and elderly (A-O) patients. Neither groups B nor C included elderly patients due of the sedative effect of Dex. Based on the previous subject's CR, the dose of RT was increased or decreased in the next patient using the sequential method. This trial would be terminated when the seventh crossover occurred, at which point the sample size met the stable estimate of the target dose. Heart rate (HR) and mean arterial pressure (MAP) were monitored throughout the trial, and sedation was assessed using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale. HR and MAP were recorded at baseline (T1), the end of Dex (T2), and the end of RT (T3), the maximum HR and MAP were recorded within 3 min of intubation from beginning to end (T4). There was a positive CR when the T4 levels rose above 15% of the baseline. The ED50/ED95 and corresponding confidence interval were calculated using probability regression. RESULTS: In total, 114 patients completed the trial. Without the use of Dex, the ED50/ED95 of TR inhibiting the positive CR caused by double-lumen bronchial intubation was 0.198/0.227 and 0.155/0.181 mg/kg in groups A-Y and A-O, respectively. The changes in vital signs from T1 to T3 were similar in the subgroups, indicating that the elderly patients were more sensitive to the dose of RT. The ED50/ED95 of RT inhibiting the positive CR caused by double-lumen endobronchial intubation was 0.122/0.150 and 0.068/0.084 mg/kg in groups B and C, respectively. And, the fluctuation of blood pressure from T3 to T4 was reduced by using Dex. RT was 100% effective in sedation with no significant inhibition of circulation. Apart from one case of hypotension occurred in group A-Y, two cases of low HR in group B, and one case of low HR in group C, no other adverse events were noted. CONCLUSIONS: The optimal dose of RT to inhibit positive CR induced by double-lumen bronchial intubation in elderly patients was 0.18 mg/kg and 0.23 mg/kg in younger patients. When the pre-use dose of Dex was 0.5 µg/kg, the optimal dose to inhibit positive CR of RT was 0.15 mg/kg. And, when the pre-use dose of Dex was 1 µg/kg, the optimal dose of RT was 0.9 mg/kg. CLINICAL TRIAL REGISTRATION: NCT05631028.

Association of DLT versus SLT with postoperative pneumonia during esophagectomy in China: a retrospective comparison study.

BACKGROUND: Double lumen tube (DLT) and single lumen tube (SLT) are two common endotracheal tube (ETT) types in esophageal cancer surgery. Evidence of the relationship between two ETT types and postoperative pneumonia (PP) remains unclear. We aimed to determine the association between two types of ETT (DLT and SLT) and PP and assess the perioperative risk-related parameters that affect PP. METHODS: This study included 680 patients who underwent esophageal cancer surgery from January 01, 2010 through December 31, 2020. The primary outcome was PP, and the secondary outcome was perioperative risk-related parameters that affect PP. The independent variable was the type of ETT: DLT or SLT. The dependent variable was PP. To determine the relationship between variables and PP, univariate and multivariate analyses were performed. The covariables included baseline demographic characteristics, comorbidity disease, neoadjuvant chemotherapy, tumor location, laboratory parameters, intraoperative related variables. RESULTS: In all patients, the incidence of postoperative pneumonia in esophagectomy was 32.77% (36.90% in DLT group and 26.38% in SLT group). After adjusting for potential risk factors, we found that using an SLT in esophagectomy was associated with lower risk of postoperative pneumonia compared to using a DLT (Odd ratio = 0.41, 95% confidence interval (CI): 0.22, 0.77, p = 0.0057). Besides DLT, smoking history, combined intravenous and inhalation anesthesia (CIIA) and vasoactive drug use were all significant and independent risk factors for postoperative pneumonia in esophagectomy. These results remained stable and reliable after subgroup analysis. CONCLUSIONS: During esophagectomy, there is significant association between the type of ETT (DLT or SLT) and PP. Patients who were intubated with a single lumen tube may have a lower rate of postoperative pneumonia than those who were intubated with a double lumen tube. This finding requires verification in follow-up studies.

A Clinical Comparison of 2 Bronchial Blockers Versus Double-Lumen Tubes for One-Lung Ventilation.

OBJECTIVES: To compare the quality of lung collapse, time, and number of attempts required to achieve lung isolation, and incidence of intraoperative malpositioning between the EZ blocker (EZB), Fuji Uniblocker (UB), and the left-sided double lumen tube (DLT). DESIGN: Prospective, randomized clinical trial. SETTING: Single tertiary-level, university-affiliated hospital. PARTICIPANTS: Eighty-nine patients undergoing elective open thoracotomies or video-assisted thoracoscopic surgery. INTERVENTIONS: The 89 patients were randomized to receive a DLT, UB, or EZB for one-lung ventilation. MEASUREMENTS AND MAIN RESULTS: The quality of lung collapse at the time of pleural opening and 10 and 20 minutes thereafter were assessed by the surgeon using the Lung Collapse Score (LCS; 0 = no lung collapse to 10 = best lung collapse). The time and number of attempts required to achieve lung isolation and the number of repositions required during surgery were measured. Tracheobronchial tree measurements were performed by radiologists from preoperative computed tomography imaging. The surgeon remained blinded to the type of device used. Twenty-nine patients were randomized to the DLT group and 30 patients to each of the EZB and UB groups. The LCSs among the groups at pleural opening and 10 minutes after pleural opening were not significantly different (p = 0.34 and p = 0.08, respectively). However, at 20 minutes after the pleural opening, the LCSs were significantly different among groups (p = 0.02), with median scores being significantly lower for DLT (9 [IQR 8-9]) than for EZB (9 [IQR 9-10]; p = 0.04) and UB (9.5 [IQR 9-10]; p = 0.02). Lung isolation was achieved fastest in the DLT group (p < 0.01). The frequency of difficult placement did not significantly differ among groups, although it occurred most frequently in UB (n = 7; 23.3%). Intraoperative repositioning also occurred most often with the UB (n = 15; 50.0%). The EZB had the greatest number of cases requiring >2 repositions (n = 4, 13.3%). There were no differences between preoperative airway measurements and time to isolation or incidence of intraoperative repositioning among the groups. CONCLUSIONS: The LCS was comparable among the 3 devices until 20 minutes after pleural opening, when better scores were obtained in the bronchial blocker groups. Lung isolation was achieved fastest with the DLT. The EZB had the highest incidence of cases requiring >2 intraoperative repositions, mostly occurring in R-sided surgery. For L-sided surgery, the EZB performed equally to the UB. This suggests that using the EZB for R-sided video-assisted thoracoscopic surgery may be suboptimal. Preoperative airway dimensions did not correlate with time to achieve isolation or incidence of intraoperative malpositioning.

Establishment of a venovenous extracorporeal membrane oxygenation in a rat model of acute respiratory distress syndrome.

INTRODUCTION: Venovenous extracorporeal membrane oxygenation (VV ECMO) is now considered a reasonable option to salvage acute respiratory distress syndrome (ARDS). However, we lack a rodent model for experimental studies. This study was undertaken to establish an animal model of VV ECMO in ARDS rats. METHODS: A total of 18 Sprague-Dawley (SD) rats (350 ± 50 g) were used in this study. Using a rat model of oleic acid (OA)-induced ARDS, VV ECMO was established through cavoatrial cannulation of the right jugular vein for venous drainage and venous reinfusion with a specially designed three-cavity catheter. Continuous arterial pressure monitoring was implemented by using a catheter through cannulation of the right femoral artery. The central temperature was monitored with a rectal probe. Arterial blood gas monitoring was implemented by a blood gas analyzer at three-time points: at baseline, 1-hour (after OA modeling), and 3.5-hour (after VV ECMO support). Lung tissue and bronchoalveolar lavage fluid were harvested respectively for protein concentration and pulmonary histologic evaluation to confirm the alleviation of lung injury during VV ECMO. RESULTS: Following ARDS induced by OA, ten rats were successfully established on VV ECMO without failure and survived the ECMO procedure. VV ECMO alleviated lung injury and restored adequate circulation for the return of lung function and oxygenation. VV ECMO was associated with decreased lung injury score, wet/dry weight ratio, and fluid leakage into airspaces. CONCLUSION: We have established a reliable, economical, and functioning ARDS rat model of VV ECMO.

Innovative use of Protek Duo during bilateral lung transplant with Veno-Arterial Extracorporeal Membrane Oxygenation assistance.

V-A ECMO during bilateral lung transplantation is routinely used when extracorporeal support is needed, in particular in case of patients affected by pulmonary hypertension. We report the case of a patient successfully transplanted with V-A ECMO assistance using a percutaneous double lumen cannula as venous drainage (Protek Duo, CardiacAssist Inc., Pittsburgh, PA) and central aortic cannulation. The double lumen cannula allowed an optimal drainage of the venous system and effective emptying of right heart chambers.

Unexpected Tension Pneumothorax after Double-Lumen Endotracheal Intubation in Patients with Pulmonary Edema: A Case Report.

Tension pneumothorax is a relatively rare complication after anesthetic induction that requires prompt diagnosis and treatment. Several handling errors related to intubation procedures or equipment and vigorous positive pressure ventilation are potentially important etiologies of tension pneumothorax in patients with underlying lung disease or in mechanically ventilated patients. We describe a case of tension pneumothorax observed after double-lumen tube (DLT) insertion followed by single-lumen tube replacement using an airway exchanger catheter in a mechanically ventilated patient. An 84-year-old female on mechanical ventilation underwent minimally invasive cardiac surgery under general anesthesia. Immediately after left-sided DLT insertion using an airway exchanger catheter, oxygen saturation decreased to 89%, peak airway pressure increased to 35 cm H2O with inadequate tidal volume, and blood pressure gradually dropped to 69/41 mmHg. Breath sounds from the right hemithorax were significantly reduced. Severe collapse of the right lung, a flattened diaphragm, and compressed abdominal organs were identified on chest radiography. Therefore, a tube thoracotomy was performed based on the findings of a tension pneumothorax. Then, oxygen saturation, peak airway pressure with adequate tidal volume, and blood pressure improved, and the distended abdomen normalized. After the pneumothorax resolved, a bronchoscopy was performed. Slight redness was noted in the right bronchus, indicating that the DLT was incorrectly inserted into the right side. In conclusion, the possibility of a tension pneumothorax should be considered during DLT intubation or endotracheal tube replacement with an airway exchange catheter.

A Mislocation of Double-lumen Catheter Guidewire in Right Atrium Successfully Retrieved with Loop-wire Snaring: A Case Report.

The increasing rate of central vascular access use especially for hemodialysis access in Indonesia carries risk of retention of the guidewire to the heart resulting in a condition known as heart foreign bodies. We described a case of mislocation of double-lumen catheter guidewire to the right atrium in a patient planned to perform hemodialysis. The patient complained of dyspnea and swelling of extremities but the symptoms had already appeared before the insertion of the catheter due to the patient's underlying kidney disease arising conclusion that the foreign bodies itself are asymptomatic. The wire was found on chest x-ray and then confirmed on fluoroscopy during the retrieval procedure. Loop-wire was used to snare the guidewire. The wire was successfully evacuated and the patient was stable. The rare nature of the condition could become a challenge in recognizing the condition. Percutaneous retrieval is the preferred management of the condition.