Effects of Positive End-expiratory Pressure on Pulmonary Perfusion Distribution and Intrapulmonary Shunt during One-lung Ventilation in Pigs: A Randomized Crossover Study.

BACKGROUND: During one-lung ventilation (OLV), positive end-expiratory pressure (PEEP) can improve lung aeration but might overdistend lung units and increase intrapulmonary shunt. The authors hypothesized that higher PEEP shifts pulmonary perfusion from the ventilated to the nonventilated lung, resulting in a U-shaped relationship with intrapulmonary shunt during OLV. METHODS: In nine anesthetized female pigs, a thoracotomy was performed and intravenous lipopolysaccharide infused to mimic the inflammatory response of thoracic surgery. Animals underwent OLV in supine position with PEEP of 0 cm H2O, 5 cm H2O, titrated to best respiratory system compliance, and 15 cm H2O (PEEP0, PEEP5, PEEPtitr, and PEEP15, respectively, 45 min each, Latin square sequence). Respiratory, hemodynamic, and gas exchange variables were measured. The distributions of perfusion and ventilation were determined by IV fluorescent microspheres and computed tomography, respectively. RESULTS: Compared to two-lung ventilation, the driving pressure increased with OLV, irrespective of the PEEP level. During OLV, cardiac output was lower at PEEP15 (5.5 ± 1.5 l/min) than PEEP0 (7.6 ± 3 l/min) and PEEP5 (7.4 ± 2.9 l/min; P = 0.004), while the intrapulmonary shunt was highest at PEEP0 (PEEP0: 48.1% ± 14.4%; PEEP5: 42.4% ± 14.8%; PEEPtitr: 37.8% ± 11.0%; PEEP15: 39.0% ± 10.7%; P = 0.027). The relative perfusion of the ventilated lung did not differ among PEEP levels (PEEP0: 65.0% ± 10.6%; PEEP5: 68.7% ± 8.7%; PEEPtitr: 68.2% ± 10.5%; PEEP15: 58.4% ± 12.8%; P = 0.096), but the centers of relative perfusion and ventilation in the ventilated lung shifted from ventral to dorsal and from cranial to caudal zones with increasing PEEP. CONCLUSIONS: In this experimental model of thoracic surgery, higher PEEP during OLV did not shift the perfusion from the ventilated to the nonventilated lung, thus not increasing intrapulmonary shunt.

Hypoxemia in School-age Children Undergoing One-lung Ventilation: A Retrospective Cohort Study from the Multicenter Perioperative Outcomes Group.

BACKGROUND: Risk factors for hypoxemia in school-age children undergoing one-lung ventilation remain poorly understood. The hypothesis was that certain modifiable and nonmodifiable factors may be associated with increased risk of hypoxemia in school-age children undergoing one-lung ventilation and thoracic surgery. METHODS: The Multicenter Perioperative Outcomes Group database was queried for children 4 to 17 yr of age undergoing one-lung ventilation. Patients undergoing vascular or cardiac procedures were excluded. The original cohort was divided into two cohorts: 4 to 9 and 10 to 17 yr of age inclusive. All records were reviewed electronically for the primary outcome of hypoxemia during one-lung ventilation, which was defined as an oxygen saturation measured by pulse oximetry (Spo2) less than 90% for 3 min or longer continuously, while severe hypoxemia was defined as Spo2 less than 90% for 5 min or longer. Potential modifiable and nonmodifiable risk factors associated with these outcomes were evaluated using separate multivariable least absolute shrinkage and selection operator regression analyses for each cohort. The covariates evaluated included age, extremes of weight, American Society of Anesthesiologists Physical Status of III or higher, duration of one-lung ventilation, preoperative Spo2 less than 98%, approach to one-lung ventilation, right operative side, video-assisted thoracoscopic surgery, lower tidal volume ventilation (defined as tidal volume of 6 ml/kg or less and positive end-expiratory pressure of 4 cm H2O or greater for more than 80% of the duration of one-lung ventilation), and procedure type. RESULTS: The prevalence of hypoxemia in the 4- to 9-yr-old cohort and the 10- to 17-yr-old cohort was 24 of 228 (10.5% [95% CI, 6.5 to 14.5%]) and 76 of 1,012 (7.5% [95% CI, 5.9 to 9.1%]), respectively. The prevalence of severe hypoxemia in both cohorts was 14 of 228 (6.1% [95% CI, 3.0 to 9.3%]) and 47 of 1,012 (4.6% [95% CI, 3.3 to 5.8%]). Initial Spo2 less than 98% was associated with hypoxemia in the 4- to 9-yr-old cohort (odds ratio, 4.20 [95% CI, 1.61 to 6.29]). Initial Spo2 less than 98% (odds ratio, 2.76 [95% CI, 1.69 to 4.48]), extremes of weight (odds ratio, 2.18 [95% CI, 1.29 to 3.61]), and right-sided cases (odds ratio, 2.33 [95% CI, 1.41 to 3.92]) were associated with an increased risk of hypoxemia in the older cohort. Increasing age (1-yr increment; odds ratio, 0.88 [95% CI, 0.80 to 0.97]) was associated with a decreased risk of hypoxemia. CONCLUSIONS: An initial room air oxygen saturation of less than 98% was associated with an increased risk of hypoxemia in all children 4 to 17 yr of age. Extremes of weight, right-sided cases, and decreasing age were associated with an increased risk of hypoxemia in children 10 to 17 yr of age.

Two-lung ventilation with artificial pneumothorax on cerebral desaturation and early postoperative cognitive outcome: a randomized controlled trial.

BACKGROUND: The effect of two lung ventilation (TLV) with carbon dioxide artificial pneumothorax on cerebral desaturation and postoperative neurocognitive changes in elderly patients undergoing elective minimally invasive esophagectomy (MIE) is unclear. OBJECTIVES: The first aim of this study was to compare the effect of TLV and one lung ventilation (OLV) on cerebral desaturation. The second aim was to assess changes in early postoperative cognitive outcomes of two ventilation methods. METHODS: This prospective, randomized, controlled trial enrolled patients 65 and older scheduled for MIE. Patients were randomly assigned (1:1) to TLV group or OLV group. The primary outcome was the incidence of cerebral desaturation events (CDE). Secondary outcomes were the cumulative area under the curve of desaturation for decreases in regional cerebral oxygen saturation (rSO2) values below 20% relative to the baseline value (AUC.20) and the incidence of delayed neurocognitive recovery. RESULTS: Fifty-six patients were recruited between November 2019 and August 2020. TLV group had a lower incidence of CDE than OLV group [3 (10.71%) vs. 13 (48.14%), P = 0.002]. TLV group had a lower AUC.20 [0 (0-35.86) % min vs. 0 (0-0) % min, P = 0.007], and the incidence of delayed neurocognitive recovery [2 (7.4%) vs. 11 (40.7%), P = 0.009] than OLV group. Predictors of delayed neurocognitive recovery on postoperative day 7 were age (OR 1.676, 95% CI 1.122 to 2.505, P = 0.006) and AUC.20 (OR 1.059, 95% CI 1.025 to 1.094, P < 0.001). CONCLUSION: Compared to OLV, TLV had a lower incidence of CDE and delayed neurocognitive recovery in elderly patients undergoing MIE. The method of TLV combined with carbon dioxide artificial pneumothorax may be an option for these elderly patients. Chinese Clinical Trial Registry (identifier: ChiCTR1900027454).

Impact of One-Lung Ventilation on Oxygenation and Ventilation Time in Thoracoscopic Heart Surgery: A Comparative Analysis with Median Thoracotomy.

BACKGROUND One-lung ventilation is the separation of the lungs by mechanical methods to allow ventilation of only one lung, particularly when there is pathology in the other lung. This retrospective study from a single center aimed to compare 49 patients undergoing thoracoscopic cardiac surgery using one-lung ventilation with 48 patients undergoing thoracoscopic cardiac surgery with median thoracotomy. MATERIAL AND METHODS This single-center retrospective study analyzed patients who underwent thoracoscopic cardiac surgery based on one-lung ventilation (experimental group, n=49). Other patients undergoing a median thoracotomy cardiac operation were defined as the comparison group (n=48). The oxygenation index and the mechanical ventilation time were also recorded. RESULTS There was no significant difference in the immediate oxygenation index between the experimental group and comparison group (P>0.05). There was no significant difference for the oxygenation index between men and women in both groups (P>0.05). The cardiopulmonary bypass time significantly affected the oxygenation index (F=7.200, P=0.009). Operation methods (one-lung ventilation thoracoscopy or median thoracotomy) affected postoperative ventilator use time (F=8.337, P=0.005). Cardiopulmonary bypass time (F=16.002, P<0.001) and age (F=4.384, P=0.039) had significant effects on ventilator use time. There was no significant effect of sex (F=0.75, P=0.389) on ventilator use time. CONCLUSIONS Our results indicated that one-lung ventilation thoracoscopic cardiac surgery did not affect the immediate postoperative oxygenation index; however, cardiopulmonary bypass time did significantly affect the immediate postoperative oxygenation index. Also, one-lung ventilation thoracoscopic cardiac surgery had a shorter postoperative mechanical ventilation use time than did traditional median thoracotomy cardiac surgery.

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.

Association between mechanical power during one-lung ventilation and pulmonary complications after thoracoscopic lung resection surgery: a prospective observational study.

BACKGROUND: The role of mechanical power on pulmonary outcomes after thoracic surgery with one-lung ventilation was unclear. We investigated the association between mechanical power and postoperative pulmonary complications in patients undergoing thoracoscopic lung resection surgery. METHODS: In this single-center, prospective observational study, 622 patients scheduled for thoracoscopic lung resection surgery were included. Volume control mode with lung protective ventilation strategies were implemented in all participants. The primary endpoint was a composite of postoperative pulmonary complications during hospital stay. Multivariable logistic regression models were used to evaluate the association between mechanical power and outcomes. RESULTS: The incidence of pulmonary complications after surgery during hospital stay was 24.6% (150 of 609 patients). The multivariable analysis showed that there was no link between mechanical power and postoperative pulmonary complications. CONCLUSIONS: In patients undergoing thoracoscopic lung resection with standardized lung-protective ventilation, no association was found between mechanical power and postoperative pulmonary complications. TRIAL REGISTRATION: Trial registration number: ChiCTR2200058528, date of registration: April 10, 2022.

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.

The Year in Thoracic Anesthesia: Selected Highlights from 2022.

This article reviews research highlights in the field of thoracic anesthesia. The highlights of this year included new developments in the preoperative assessment and prehabilitation of patients requiring thoracic surgery, updates on the use of devices for one-lung ventilation (OLV) in adults and children, updates on the anesthetic and postoperative management of these patients, including protective OLV ventilation, the use of opioid-sparing techniques and regional anesthesia, and outcomes using enhanced recovery after surgery, as well as the use of expanding indications for extracorporeal membrane oxygenation, specialized anesthetic techniques for airway surgery, and nonintubated video-assisted thoracic surgery.

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.

One-lung Ventilation for Patients With Laryngo-tracheal Stenosis: A Case Report and Literature Review.

Context: Laryngo-tracheal stenosis (LTS) is a relatively rare disease, and conventional methods have difficulty achieving one-lung ventilation (OLV) when an anatomical abnormality exists. Selecting an appropriate method for patients with LTS can ensure oxygenation, collapse the lung, and reduce damage. Objective: The study intended to perform a comprehensive review of the literature and a systematic review to examine the characteristics and management of OLV for LTS patients. Design: The research team performed a narrative review by searching the PubMed and China National Knowledge Infrastructure (CNKI) databases. The search used the keywords one-lung ventilation and tracheal stenosis. The team then performed a review, including the studies found in the search and the research team's own case study. Setting: The study took place at the First Hospital of Jilin University in Changchun, Jilin, China. Participant: The participant in the current case study was a 72-year-old, female patient with generalized tracheal narrowing. Results: Nine participants achieved OLV through BB, with the anesthesiologist performing SLT and using extraluminal BB for six participants. Conclusions: Several methods can successfully achieve OLV for patients with difficult airways, but the current research team found that a small, single-lumen tube (SLT) and extraluminal bronchial blocker (BB) may be a better choice for patients with tracheal stenosis.

Ultrasound-guided versus conventional lung recruitment manoeuvres in thoracic surgery: a randomised controlled study.

Lung recruitment manoeuvres (RMs) during mechanical ventilation may reduce atelectasis, however, the optimal recruitment strategy for patients undergoing thoracic surgery remains unknown. Our study was designed to investigate whether ultrasound-guided lung RMs is superior to conventional RMs in reducing perioperative atelectasis during thoracic surgery with one-lung ventilation. We conducted a randomised controlled clinical trial from August 2022 to September 2022. Sixty patients scheduled for video-assisted thoracoscopic surgery (VATS) under general anaesthesia were enrolled. Subjects were randomly divided into the ultrasound-guided RMs group (manual inflation guided by lung ultrasound) or conventional RMs group (manual inflation with 30 cmH2O pressure). Lung ultrasound were performed at three predefined time points (1 min after anaesthetic induction; after RMs at the end of surgery; before discharge from postanesthesia care unit [PACU]). The primary outcome was lung ultrasound score before discharge from the PACU after extubation. In the early postoperative period, lung aeration deteriorated in both groups even after lung RMs. However, ultrasound-guided lung RMs had significantly lower lung ultrasound scores when compared with conventional RMs in bilateral lungs (2.0 [0.8-4.0] vs. 8.0 [3.8-10.3], P < 0.01) at the end of surgery, which remained before patients discharged from the PACU. Accordingly, the lower incidence of atelectasis was found in ultrasound-guided RMs group than in conventional RMs group (7% vs. 53%; P < 0.01) at the end of surgery. Ultrasound-guided RMs is superior to conventional RMs in improving lung aeration and reducing the incidence of lung atelectasis at early postoperative period in patients undergoing VATS. The study protocol was approved by the Institutional Review Board of the Fudan University Shanghai Cancer Center (No. 220,825,810; date of approval: August 5, 2022) and registered on Chinese Clinical Trial Registry (registration number: ChiCTR2200062761).

Impact of pharmacological interventions on intrapulmonary shunt during one-lung ventilation in adult thoracic surgery: a systematic review and component network meta-analysis.

BACKGROUND: Intrapulmonary shunt is a major determinant of oxygenation in thoracic surgery under one-lung ventilation. We reviewed the effects of available treatments on shunt, Pao2/FiO2 and haemodynamics through systematic review and network meta-analysis. METHODS: Online databases were searched for RCTs comparing pharmacological interventions and intrapulmonary shunt in thoracic surgery under one-lung ventilation up to March 30, 2022. Random-effects (component) network meta-analysis compared 24 treatments and 19 treatment components. The Confidence in Network Meta-Analysis (CINeMA) framework assessed evidence certainty. The primary outcome was intrapulmonary shunt fraction during one-lung ventilation. RESULTS: A total of 55 RCTs were eligible for systematic review (2788 participants). The addition of N2O (mean difference [MD]=-15%; 95% confidence interval [CI], -25 to -5; P=0.003) or almitrine (MD=-13%; 95% CI, -20 to -6; P<0.001) to propofol anaesthesia were efficient at decreasing shunt. Combined epidural anaesthesia (MD=3%; 95% CI, 1-5; P=0.005), sevoflurane (MD=5%; 95% CI, 2-8; P<0.001), isoflurane (MD=6%; 95% CI, 4-9; P<0.001), and desflurane (MD=9%; 95% CI, 4-14; P=0.001) increased shunt vs propofol. Almitrine (MD=147 mm Hg; 95% CI, 58-236; P=0.001), dopexamine (MD=88 mm Hg; 95% CI, 4-171; P=0.039), and iloprost (MD=81 mm Hg; 95% CI, 4-158; P=0.038) improved Pao2/FiO2. Certainty of evidence ranged from very low to moderate. CONCLUSIONS: Adding N2O or almitrine to propofol anaesthesia reduced intrapulmonary shunt during one-lung ventilation. Halogenated anaesthetics increased shunt in comparison with propofol. The effects of N2O, iloprost, and dexmedetomidine should be investigated in future research. N2O results constitute a research hypothesis currently not backed by any direct evidence. The clinical availability of almitrine is limited. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42022310313.

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.

One-lung ventilation with a bronchial blocker in thoracic patients.

BACKGROUND: Lung isolation is a technique used in a multitude of surgeries to ensure single-lung ventilation with collapse of the contralateral lung, as to achieve improved access and visualization of relevant anatomical structures. Despite being accepted and having favorable outcomes, bronchial blockers (BBs) are not to this day the main device of choice among anaesthesiologists. METHODS: In this retrospective and descriptive study, we analyzed the safety and efficacy of a BB in all types of thoracic surgeries in our centre between 2015 and 2022, excluding patients with massive hemoptysis or empyema, or who had undergone a prior pneumonectomy. RESULTS: One hundred and thirty-four patients were intervened due to lung cancer (67.9%), respiratory disease (23.9%), and non-respiratory disease (8.2%) undergoing lung surgeries (65.7%), pleural and mediastinal surgeries (29.9%), chest wall surgeries (3.0%) and other surgeries (1.5%). In most cases, lung collapse was considered excellent (63.9%) or good (33.1%) with only 4 cases (3.0%) of poor lung collapse. More than 90% of patients did not present intraoperative or immediate postoperative complications. No statistically significant differences were found between lung collapse and the demographic, clinical or BB-related variables (p > 0.05). However, we found a significatively higher proportion of excellent lung collapses in VATS surgeries and lateral decubitus positioning, as well as a significatively less proportion of poor lung collapses (p < 0.05). Moreover, there was a significantly higher proportion of excellent lung collapses when the BB was placed in the left bronchus (p < 0.05). CONCLUSIONS: With these results, in our experience BBs constitute an effective alternative, capable of achieving pulmonary collapse in all kinds of thoracic procedures with satisfactory safety rates due to their minimal complications.

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.

Propofol Versus Remimazolam on Cognitive Function, Hemodynamics, and Oxygenation During One-Lung Ventilation in Older Patients Undergoing Pulmonary Lobectomy: A Randomized Controlled Trial.

OBJECTIVES: To investigate the effects of remimazolam on postoperative cognitive function, intraoperative hemodynamics, and oxygenation in older patients undergoing lobectomy. DESIGN: A prospective, double-blind, randomized, controlled study. SETTING: A university hospital. PARTICIPANTS: Eighty-four older patients with lung cancer who underwent lobectomy, aged ≥65 years. INTERVENTIONS: Patients were divided randomly into the remimazolam (group R) and propofol (group P) groups. Group R underwent remimazolam anesthesia induction and maintenance, whereas group P underwent propofol anesthesia induction and maintenance. Cognitive function was assessed with neuropsychological tests 1 day before surgery and 7 days after surgery. The Clock Drawing Test, Verbal Fluency Test (VFT), Digit Symbol Switching Test (DSST), and Auditory Verbal Learning Test-Huashan (AVLT-H) assessed visuospatial ability, language function, attention, and memory, respectively. The systolic blood pressure (SBP), heart rate, mean arterial pressure (MAP), and cardiac index were recorded 5 minutes before induction of anesthesia (T0), 2 minutes after sedation (T1), 5 minutes after intubation with two-lung ventilation (T2), 30 minutes after one-lung ventilation (OLV) (T3), 60 minutes after OLV (T4), and at the end of surgery (T5), and the incidences of hypotension and bradycardia were recorded. The PaO2, oxygenation index (OI), and intrapulmonary shunt (Qs/Qt) were assessed at T0, T2, T3, T4, and T5. The levels of S-100ß and interleukin 6 were measured by enzyme-linked immunosorbent assay at T0, T5, 24 hours after surgery (T6), and on day 7 after surgery (T7). MEASUREMENTS AND MAIN RESULTS: The VFT, DSST, immediate recall AVLT-H, and short-delayed recall AVLT-H scores were significantly higher in group R than in group P on day 7 after surgery (p < 0.05). The SBP and MAP at T2 to T5 were significantly higher in group R than in group P, the incidence of hypotension was significantly lower in group R (9.5%) than in group P (35.7%) (p = 0.004), and remimazolam significantly reduced the dose of phenylephrine used (p < 0.05). The PaO2 and OI at T4 were significantly higher in group R than in group P, and Qs/Qt was significantly lower in group R than in group P. The levels of S-100ß at T5 were significantly lower in group R than in group P (p < 0.05). CONCLUSION: The results showed that remimazolam (versus propofol) may lessen the degree of short-term postoperative cognitive dysfunction measured by standard neuropsychological tests, better optimize intraoperative hemodynamics, and lead to improved oxygenation during OLV.

Modified technique for endobronchial blocker placement in pediatric patients undergoing thoracic surgery.

BACKGROUND: One lung ventilation (OLV) in small children can be achieved using an Arndt endobronchial blocker (AEBB), but it presents challenges. OLV during thoracic procedures provides better surgical conditions and postoperative outcomes. AIM: To report a novel technique to improve placement and repositioning of an extraluminal AEBB for OLV. MATERIAL AND METHODS: We describe how an angled wire is successfully used for extraluminal AEBB placement in pediatric thoracic procedures. DISCUSSION: Since 2017, we have successfully used this technic in over 50 infants and toddlers and overcome challenges of the classic OLV in this age group. CONCLUSIONS: The described technique allows for fast, safe, and reliable OLV while maintaining the ability to reposition the AEBB.

[Video-assisted Double-lumen Tubes in Robot-assisted Oesophageal Surgery]. / Videogestützte Doppellumentuben in der roboterassistierten Ösophaguschirurgie.

Robot-assisted esophagectomies are still considered high-risk procedures requiring complex surgical and anesthesiological planning and coordination. The operative space during the thoracic operative part is created by one-lung ventilation. Due to special patient positioning and intraoperative repositioning maneuvers, however, access to patient airway or double-lumen tube manipulation, if necessary, is only possible to a certain extent. In this work, we present our experiences establishing a video-guided double-lumen tube for esophageal surgery. From our point of view, the use of video-guided double-lumen tubes is very suitable increasing patient safety and coordination in the operational team during esophagectomy.

Effect of Positive End-Expiratory Pressure (PEEP) Titration in Elderly Patients Undergoing Lobectomy.

BACKGROUND Currently, one-lung ventilation in thoracoscopic lobectomy adopts mostly a protective ventilation mode, which includes low tidal volume (a tidal volume of 6 mL/kg predicted body weight), positive end-expiratory pressure (PEEP), and intermittent lung inflation. However, there is no clear conclusion regarding the value of PEEP in elderly patients undergoing lobectomy. MATERIAL AND METHODS Fifty patients who underwent video-assisted thoracoscopic unilateral lobectomy, aged 65 to 78 years, with a body mass index of 18 to 29 kg/m² and ASA grades I to III, were randomly divided into 2 groups (n=25 each): optimal oxygenation titration group (group O) and optimal compliance titration group (group C). Mean arterial pressure (MAP), heart rate (HR), and central venous pressure (CVP) were recorded in both groups at different time points. The radial artery blood samples were collected at 3 time points for blood gas analysis, and the void volume/tidal volume ratio was calculated. The peak airway pressure and PEEP values were recorded at 4 min after the completion of one-lung ventilation titration (T2), and the driving pressure was calculated. RESULTS The best PEEP value of titration in the best compliance group was lower than that of the best oxygenation method, the peak was lower, and the dynamic lung compliance was higher; however, this had no effect on MAP and HR. The CVP was lower than optimal oxygenation at T2. CONCLUSIONS Dynamic lung compliance-guided PEEP titration improved lung function in elderly patients undergoing lobectomy.