Comparative effects of variable versus conventional volume-controlled one-lung ventilation on gas exchange and respiratory system mechanics in thoracic surgery patients: A randomized controlled clinical trial

BACKGROUND

Mechanical ventilation with variable tidal volumes (V-VCV) has the potential to improve lung function during general anesthesia. We tested the hypothesis that V-VCV compared to conventional volume-controlled ventilation (C-VCV) would improve intraoperative arterial oxygenation and respiratory system mechanics in patients undergoing thoracic surgery under one-lung ventilation (OLV).

METHODS

Patients were randomized to V-VCV (n = 39) or C-VCV (n = 39). During OLV tidal volume of 5 mL/kg predicted body weight (PBW) was used. Both groups were ventilated with a positive end-expiratory pressure (PEEP) of 5 cm H2O, inspiration to expiration ratio (I:E) of 1:1 (during OLV) and 1:2 during two-lung ventilation, the respiratory rate (RR) titrated to arterial pH, inspiratory peak-pressure ≤ 40 cm H2O and an inspiratory oxygen fraction of 1.0.

RESULTS

Seventy-five out of 78 Patients completed the trial and were analyzed (dropouts were excluded). The partial pressure of arterial oxygen (PaO2) 20 min after the start of OLV did not differ among groups (V-VCV: 25.8 ± 14.6 kPa vs C-VCV: 27.2 ± 15.3 kPa; mean difference [95% CI]: 1.3 [-8.2, 5.5], P = 0.700). Furthermore, intraoperative gas exchange, intraoperative adverse events, need for rescue maneuvers due to desaturation and hypercapnia, incidence of postoperative pulmonary and extra-pulmonary complications, and hospital free days at day 30 after surgery did not differ between groups.

CONCLUSIONS

In thoracic surgery patients under OLV, V-VCV did not improve oxygenation or respiratory system mechanics compared to C-VCV. Ethical Committee: EK 420092019.

TRIAL REGISTRATION

at the German Clinical Trials Register: DRKS00022202 (16.06.2020).

One-lung ventilation with fixed and variable tidal volumes on oxygenation and pulmonary outcomes: A randomized trial

OBJECTIVE

Test the hypothesis that one-lung ventilation with variable tidal volume improves intraoperative oxygenation and reduces postoperative pulmonary complications after lung resection.

BACKGROUND

Constant tidal volume and respiratory rate ventilation can lead to atelectasis. Animal and human ARDS studies indicate that oxygenation improves with variable tidal volumes. Since one-lung ventilation shares characteristics with ARDS, we tested the hypothesis that one-lung ventilation with variable tidal volume improves intraoperative oxygenation and reduces postoperative pulmonary complications after lung resection.

DESIGN

Randomized trial.

SETTING

Operating rooms and a post-anesthesia care unit.

PATIENTS

Adults having elective open or video-assisted thoracoscopic lung resection surgery with general anesthesia were randomly assigned to intraoperative ventilation with fixed (n = 70) or with variable (n = 70) tidal volumes.

INTERVENTIONS

Patients assigned to fixed ventilation had a tidal volume of 6 ml/kgPBW, whereas those assigned to variable ventilation had tidal volumes ranging from 6 ml/kg PBW ± 33% which varied randomly at 5-min intervals.

MEASUREMENTS

The primary outcome was intraoperative oxygenation; secondary outcomes were postoperative pulmonary complications, mortality within 90 days of surgery, heart rate, and SpO2/FiO2 ratio.

RESULTS

Data from 128 patients were analyzed with 65 assigned to fixed-tidal volume ventilation and 63 to variable-tidal volume ventilation. The time-weighted average PaO2 during one-lung ventilation was 176 (86) mmHg in patients ventilated with fixed-tidal volume and 147 (72) mmHg in the patients ventilated with variable-tidal volume, a difference that was statistically significant (p < 0.01) but less than our pre-defined clinically meaningful threshold of 50 mmHg. At least one composite complication occurred in 11 (17%) of patients ventilated with variable-tidal volume and in 17 (26%) of patients assigned to fixed-tidal volume ventilation, with a relative risk of 0.67 (95% CI 0.34-1.31, p = 0.24). Atelectasis in the ventilated lung was less common with variable-tidal volumes (4.7%) than fixed-tidal volumes (20%) in the initial three postoperative days, with a relative risk of 0.24 (95% CI 0.01-0.8, p = 0.02), but there were no significant late postoperative differences. No other secondary outcomes were both statistically significant and clinically meaningful.

CONCLUSION

One-lung ventilation with variable tidal volume does not meaningfully improve intraoperative oxygenation, and does not reduce postoperative pulmonary complications.

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.

Advances in Minimally Invasive Procedures of the Thoracic Cavity

Significant advances in veterinary minimally invasive surgeries and procedures have occurred in the past 10 years. These advances have been allowed due to continual research into optimizing working space through one-lung ventilation techniques and carbon dioxide insufflation. Additionally, minimally invasive surgery enthusiasts have joined forces with interventionalists and, in many cases, physicians to push the boundaries, minimize pain, suffering, and time away from owners with advances in a variety of procedures. Several larger multi-institutional retrospective studies on various disease processes allow veterinarians and owners to understand that minimally invasive approaches allow for outcomes comparable to traditional open surgery and, in some cases, may now be considered the standard of care in canine and feline patients.

Effects of unilateral superimposed high-frequency jet ventilation on porcine hemodynamics and gas exchange during one-lung flooding

BACKGROUND

Superimposed high-frequency jet ventilation (SHFJV) is suitable for respiratory motion reduction and essential for effective lung tumor ablation. Fluid filling of the target lung wing one-lung flooding (OLF) is necessary for therapeutic ultrasound applications. However, whether unilateral SHFJV allows adequate hemodynamics and gas exchange is unclear.

AIM

To compared SHFJV with pressure-controlled ventilation (PCV) during OLF by assessing hemodynamics and gas exchange in different animal positions.

METHODS

SHFJV or PCV was used alternatingly to ventilate the non-flooded lungs of the 12 anesthetized pigs during OLF. The animal positions were changed from left lateral position to supine position (SP) to right lateral position (RLP) every 30 min. In each position, ventilation was maintained for 15 min in both modalities. Hemodynamic variables and arterial blood gas levels were repeatedly measured.

RESULTS

Unilateral SHFJV led to lower carbon dioxide removal than PCV without abnormally elevated carbon dioxide levels. SHFJV slightly decreased oxygenation in SP and RLP compared with PCV; the lowest values of PaO2 and PaO2/FiO2 ratio were found in SP [13.0; interquartile range (IQR): 12.6-5.6 and 32.5 (IQR: 31.5-38.9) kPa]. Conversely, during SHFJV, the shunt fraction was higher in all animal positions (highest in the RLP: 0.30).

CONCLUSION

In porcine model, unilateral SHFJV may provide adequate ventilation in different animal positions during OLF. Lower oxygenation and CO2 removal rates compared to PCV did not lead to hypoxia or hypercapnia. SHFJV can be safely used for lung tumor ablation to minimize ventilation-induced lung motion.

Placement of bronchial occluder outside the tracheal tube in a patient combined with airway compression undergoing mediastinal tumors resection: a case report

BACKGROUND

Mediastinal tumors pose a challenging respiratory and circulatory management during anesthesia procedures, there is a risk of circulatory collapse or complete airway obstruction, which in severe cases can lead to cardiac arrest. We reported a case of anesthetic management using a bronchial blocker placed outside the tracheal tube. In this case report, the patient's trachea was so severely compressed that the airway was extremely narrow, only 4 mm at its narrowest point. By reporting the anesthetic management of this patient, we intend to provide an unusual approach for airway management.

CASE PRESENTATION

A 52-year-old male patient was admitted to the hospital due to cough and expectoration for one year. Additionally, the patient experienced chest tightness and asthma after physical activity. The enhanced computed tomography revealed there existed an irregular soft tissue mass in the right upper mediastinum, which significantly compressed the trachea and esophagus. The results of the mediastinal puncture pathology showed the presence of mesenchymal tumors. According to the results above, the patient was diagnosed with a mediastinal tumor and scheduled to undergo tumor resection under general anesthesia. We used a bronchial occluder outside the tracheal tube for general anesthesia. After surgery, the patient received thorough treatment and was subsequently discharged from the hospital.

CONCLUSION

In patients with severe airway compression from a mediastinal tumor airway compression, positioning a bronchial occluder externally to the tracheal tube is an effective method of airway management. However, we still need more clinical practice to help the process become more standardized.

Effects of positive end-expiratory pressure on regional cerebral oxygen saturation in elderly patients undergoing thoracic surgery during one-lung ventilation: a randomized crossover-controlled trial

BACKGROUND

A significant reduction in regional cerebral oxygen saturation (rSO2) is commonly observed during one-lung ventilation (OLV), while positive end-expiratory pressure (PEEP) can improve oxygenation. We compared the effects of three different PEEP levels on rSO2, pulmonary oxygenation, and hemodynamics during OLV.

METHODS

Forty-three elderly patients who underwent thoracoscopic lobectomy were randomly assigned to one of six PEEP combinations which used a crossover design of 3 levels of PEEP-0 cmH2O, 5 cmH2O, and 10 cmH2O. The primary endpoint was rSO2 in patients receiving OLV 20 min after adjusting the PEEP. The secondary outcomes included hemodynamic and respiratory variables.

RESULTS

After exclusion, thirty-six patients (36.11% female; age range: 60-76 year) were assigned to six groups (n = 6 in each group). The rSO2 was highest at OLV(0) than at OLV(10) (difference, 2.889%; [95% CI, 0.573 to 5.204%]; p = 0.008). Arterial oxygen partial pressure (PaO2) was lowest at OLV(0) compared with OLV(5) (difference, -62.639 mmHg; [95% CI, -106.170 to -19.108 mmHg]; p = 0.005) or OLV(10) (difference, -73.389 mmHg; [95% CI, -117.852 to -28.925 mmHg]; p = 0.001), while peak airway pressure (Ppeak) was lower at OLV(0) (difference, -4.222 mmHg; [95% CI, -5.140 to -3.304 mmHg]; p < 0.001) and OLV(5) (difference, -3.139 mmHg; [95% CI, -4.110 to -2.167 mmHg]; p < 0.001) than at OLV(10).

CONCLUSIONS

PEEP with 10 cmH2O makes rSO2 decrease compared with 0 cmH2O. Applying PEEP with 5 cmH2O during OLV in elderly patients can improve oxygenation and maintain high rSO2 levels, without significantly increasing peak airway pressure compared to not using PEEP.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2200060112 on 19 May 2022.

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).

Effects of nonintubated thoracoscopic surgery on postoperative neurocognitive function: a randomized controlled trial

OBJECTIVES

Postoperative neurocognitive disorder following thoracoscopic surgery with general anaesthesia may be linked to reduced intraoperative cerebral oxygenation and perioperative inflammation, which can potentially be exacerbated by mechanical ventilation. However, nonintubated thoracoscopic surgery, which utilizes regional anaesthesia and maintains spontaneous breathing, provides a unique model for studying the potential benefits of avoiding mechanical ventilation. This approach allows investigation into the impact on perioperative neurocognitive profiles, inflammatory responses and intraoperative cerebral oxygen levels.

METHODS

In total, 110 patients undergoing thoracoscopic surgery were randomly equally assigned to the intubated group and the nonintubated group. Regional cerebral oxygenation was monitored during surgery. Serum neuroinflammatory biomarkers, including interleukin-6 and glial fibrillary acidic protein, were measured at baseline (before surgery) and 24 h after surgery. Postoperative complication severity was compared using the Comprehensive Complication Index. The primary outcome was perioperative changes in neurocognitive test score, which was assessed at baseline, 24 h and 6 months after surgery.

RESULTS

Patients in the nonintubated group had higher neurocognitive test scores at 24 h (69.9 ± 10.5 vs 65.3 ± 11.8; P = 0.03) and 6 months (70.6 ± 6.7 vs 65.4 ± 8.1; P < 0.01) after surgery and significantly higher regional cerebral oxygenation over time during one-lung ventilation (P = 0.03). Patients in the intubated group revealed a significantly higher postoperative serum interleukin-6 level (group by time interaction, P = 0.04) and a trend towards a significantly higher serum glial fibrillary acidic protein level (group by time interaction, P = 0.11). Furthermore, patients in the nonintubated group had a significantly lower Comprehensive Complication Index (9.0 ± 8.2 vs 6.1 ± 7.1; P < 0.05).

CONCLUSIONS

Nonintubated thoracoscopic surgery was associated with improved postoperative neurocognitive recovery, more stable intraoperative cerebral oxygenation, ameliorated perioperative inflammation and attenuated postoperative complication severity.

Preoperative preparation and postoperative care in children in thoracic surgery

Anesthesia for pediatric patients undergoing thoracic surgery continues to be distinctive due to differing anatomical and physiological characteristics compared to adults. Adequate preoperative preparation, appropriate tool selection for providing one-lung ventilation, perioperative pain management, and a multidisciplinary approach can ensure higher quality postoperative care. In this review, the perioperative anesthesia management for pediatric patients undergoing thoracic surgery will be discussed, starting from the preoperative preparation phase. Additionally, the issues related to the application and management of one-lung ventilation will also be assessed.

Transcutaneous electrical acupoint stimulation improves pulmonary function by regulating oxidative stress during one-lung ventilation in patients with lung cancer undergoing thoracoscopic surgery: a randomized controlled trial

BACKGROUND

Our aim was to evaluate the efficacy of transcutaneous electrical acupoint stimulation (TEAS) on oxidative stress induced by one-lung ventilation, lung function, and postoperative quality of recovery in patients with lung cancer.

METHODS

The participants (n = 80) were assigned to the sham group and TEAS group. TEAS on bilateral Feishu (BL13), Zusanli (ST36), and Hegu (L14) was performed 30 minutes before induction of anesthesia and continued until the end of the surgery. In the sham group, the same acupoints were selected without electrical stimulation. PaO2/FiO2, intrapulmonary shunt ratio (Qs/Qt), alveolar-arterial oxygen tension (A-aDO2), and respiratory index (RI) were calculated to evaluate lung function before one-lung ventilation (T0), 30 min after one-lung ventilation (T1), 1 h after one-lung ventilation (T2), and 10 min after resuming two-lung ventilation (T3). The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were detected to estimate oxidative stress at T0, T1, T2, and T3. Secondary outcomes included removal time of thoracic drainage tube, duration of intensive care unit (ICU) stay, length of postoperative hospitalization, the incidence of postoperative pulmonary complications, and the Quality of Recovery-15 (QoR-15) score on postoperative day 1 and 2.

RESULTS

TEAS significantly increased PaO2/FiO2 at T1 and T2, while Qs/Qt, A-aDO2, and RI decreased remarkably from T1 to T3 (P < 0.05). Meanwhile, TEAS obviously decreased MDA and increased SOD activity at T2 and T3 (P < 0.05). Furthermore, TEAS also markedly shortened the length of ICU stay and hospital stay after surgery, whereas the QoR-15 score on postoperative day 1 and 2 was significantly higher (P < 0.05).

CONCLUSIONS

TEAS could reduce oxidative lung injury during one-lung ventilation, thereby protecting pulmonary function and effectively accelerating the early recovery of patients with lung cancer.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2000038243).

Effect of thermal softening of double-lumen endobronchial tubes on postoperative sore throat in patients with prior SARS-CoV-2 infection: a randomized controlled trial

BACKGROUND

The incidence of postoperative sore throat (POST) after tracheal intubation using double-lumen endobronchial tubes (DLTs) is higher in patients with prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection than in the general population. This prospective trial was conducted to determine whether thermal softening of DLTs could decrease the incidence of POST or other airway injuries in patients with prior SARS-CoV-2 infection.

METHODS

A total of 120 patients with prior SARS-CoV-2 infection undergoing thoracoscopic surgery were randomly assigned to two groups (n = 60 each). In the thermal softening group, the distal portion of the DLT was placed in thermostatic saline (50 °C) for 10 min before endotracheal intubation. In the control group, the distal portion of the DLT was placed in room temperature saline for 10 min before endotracheal intubation. The incidence and severity of POST and hoarseness were assessed at 1, 6 and 24 h postoperatively. The primary outcomes were the incidence and severity of POST at 6 h postoperatively. The secondary outcomes were the incidence and severity of hoarseness, vocal cord and tracheal injuries, and hemodynamic changes in patients at intubation.

RESULTS

The incidence of POST at 6 h postoperatively was greater in the control group than in the thermal softening group [41 (68%) vs. 22 (37%), P = 0.001]. The overall incidence of POST at 24 h postoperatively was greater in the control group than in the thermal softening group [46 (76%) vs. 24 (40%), P < 0.001]. The overall incidence of tracheal injuries was also greater in the control group than in the thermal softening group (P = 0.016). Vocal cord injuries occurred more frequently in the control group than in the thermal softening group (P = 0.006).

CONCLUSION

Thermal softening of DLTs before intubation can reduce the incidence of POST and airway injuries in patients with prior SARS-CoV-2 infection undergoing DLT insertion.

TRIAL REGISTRATION

This trial has been registered at www.chictr.org.cn (registration number: ChiCTR2200066821; registration date: December 19, 2022).

Effects of dexmedetomidine on pulmonary function in patients receiving one-lung ventilation: a meta-analysis of randomized controlled trial

BACKGROUND

Mechanical ventilation, particularly one-lung ventilation (OLV), can cause pulmonary dysfunction. This meta-analysis assessed the effects of dexmedetomidine on the pulmonary function of patients receiving OLV.

METHODS

The Embase, PubMed, MEDLINE, Cochrane Library, ClinicalTrials.gov, and Chinese Clinical Trial Registry databases were systematically searched. The primary outcome was oxygenation index (OI). Other outcomes including the incidence of postoperative complications were assessed.

RESULTS

Fourteen randomized controlled trials involving 845 patients were included in this meta-analysis. Dexmedetomidine improved the OI at 30 (mean difference [MD]: 40.49, 95% CI [10.21, 70.78]), 60 (MD: 60.86, 95% CI [35.81, 85.92]), and 90 min (MD: 55, 95% CI [34.89, 75.11]) after OLV and after surgery (MD: 28.98, 95% CI [17.94, 40.0]) and improved lung compliance 90 min after OLV (MD: 3.62, 95% CI [1.7, 5.53]). Additionally, dexmedetomidine reduced the incidence of postoperative pulmonary complications (odds ratio: 0.44, 95% CI [0.24, 0.82]) and length of hospital stay (MD: -0.99, 95% CI [-1.25, -0.73]); decreased tumor necrosis factor-α, interleukin (IL)-6, IL-8, and malondialdehyde levels; and increased superoxide dismutase levels. However, only the results for the OI and IL-6 levels were confirmed by the sensitivity and trial sequential analyses.

CONCLUSIONS

Dexmedetomidine improves oxygenation in patients receiving OLV and may additionally decrease the incidence of postoperative pulmonary complications and shorten the length of hospital stay, which may be related to associated improvements in lung compliance, anti-inflammatory effects, and regulation of oxidative stress reactions. However, robust evidence is required to confirm these conclusions.

Association between Oxygen Reserve index and arterial partial pressure of oxygen during one-lung ventilation: a retrospective cohort study

PURPOSE

We aimed to investigate the association between the Oxygen Reserve index (ORi) and arterial partial pressure of oxygen (PaO2) during one-lung ventilation in patients who underwent non-cardiac thoracic surgery requiring one-lung ventilation.

METHODS

This retrospective study assessed the eligibility of 578 adult patients who underwent elective non-cardiac thoracic surgery requiring one-lung ventilation at a tertiary hospital, and their electronic medical records were reviewed. The ORi monitor was used in all patients during anesthesia, and arterial blood gas analysis was routinely performed 15 min after the initiation of one-lung ventilation. The primary endpoint was the association between ORi and PaO2 which were measured simultaneously during one-lung ventilation. We also investigated the risk factors for PaO2 less than 150 mmHg during one-lung ventilation.

RESULTS

Total of 554 patient were included in the analysis. The ORi value measured 15 min after the start of one-lung ventilation was significantly associated with PaO2 in the linear regression model (r2 = 0.5752, P < 0.001), and 0.27 of the ORi value could distinguish PaO2 ≥ 150 mmHg (sensitivity 0.909, specificity 0.932). Risk factors for PaO2 < 150 mmHg during one-lung ventilation included a lower ORi, older age, higher body mass index, left-sided one-lung ventilation, and lower hemoglobin concentrations.

CONCLUSION

This study suggested that ORi could provide useful information on arterial oxygenation even during one-lung ventilation for non-cardiac thoracic surgery.

Association of mechanical power during one-lung ventilation and post-operative pulmonary complications among patients undergoing lobectomy: a protocol for a prospective cohort study

The association of intra-operative mechanical power (MP) with post-operative pulmonary complications (PPCs) has been described before, but it is uncertain whether the potential inherent bias can limit the use of this parameter, particularly in the context of one-lung ventilation. This single-center study aims to investigate the effect of MP during one-lung ventilation (OLV), and the risks of PPCs in patients undergoing thoracoscopic lobectomy. This prospective observational study is being conducted in an academic tertiary hospital in mainland China. Participants diagnosed with lung cancer, and aged 50 to 80 years are eligible. Video-assisted thoracoscopic surgery (VATS) lobectomy is performed for all patients. The primary outcome is the occurrence of PPCs over 5 consecutive days after the surgery, or until discharge from the hospital. Secondary outcomes include the composite conditions of PPCs, in-hospital stay, systematic inflammation tested by blood samples, and changes in aeration compartments in the ventilated lung as assessed by CT scans. We aim to evaluate the association of mean MP and the temporal patterns in the trend of MP during OLV with the occurrence of PPCs. A total of 120 patients will be enrolled in this study. The study protocol has received approval from the Ethics Committee of the affiliated hospital of Southwest Medical University, China (Reference number: KY2022162). The findings will be made available to the funder and researchers via scientific conferences and peer-reviewed publications. This controlled trial was approved by the Ethics Committee of Southwest Medical University(ChiCTR2200062173), and registered in the Chinese Clinical Trial Register website ( http://www.chictr.org.cn/edit.aspx?pid=172533&htm=4 , ChiCTR2200062173). A written consent was obtained from each patient.

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.

Anesthetic management of thoracotomy for massive intrathoracic solitary fibrous tumor of the pleura: a case report

BACKGROUNDS

Solitary fibrous tumor of the pleura (SFTP) is a rare thoracic tumor and usually asymptomatic. Massive SFTP may affect adjacent organs and tissues including pulmonary vasculature, bronchus and heart. A thoracotomy for massive SFTP is necessary in severe case. Therefore, it is important for anesthesiologists to understand the condition of patients with massive SFTP and develop an appropriate anesthetic management strategy. A 76-year-old woman with massive SFTP presented to our clinical center and was evaluated as requiring thoracotomy. She received multidisciplinary cooperation treatment from the radiology, cardiac, thoracic surgery and anesthetic teams. The perioperative management of anesthesiologists played a crucial role in the great prognosis of this woman.

CONCLUSIONS

This case report demonstrates the importance of comprehensive and meticulous perioperative management and provides guidance to the multidisciplinary team on the potential risk and the rational treatment strategy of patients with massive SFTP during the perioperative period.

Intensity of one-lung ventilation and postoperative respiratory failure: A hospital registry study

BACKGROUND

Studies linked a high intensity of mechanical ventilation, measured as high mechanical power (MP) to postoperative respiratory failure (PRF) in the setting of two-lung ventilation. We investigated whether a higher MP during one-lung ventilation (OLV) is associated with PRF.

METHODS

In this registry-based study, adult patients who underwent general anesthesia with OLV for thoracic surgeries between 2006 and 2020 at a New England tertiary healthcare network were included. The association between MP during OLV and PRF (emergency non-invasive ventilation or reintubation within seven days) was assessed in a cohort weighted through a generalized propensity score conditional on a priori defined preoperative and intraoperative factors. Dominance of components of MP and intensity of OLV versus two-lung ventilation in predicting PRF was investigated.

RESULTS

Out of 878 included patients, 106 (12.1%) developed PRF. The median (IQR) MP during OLV was 9.8 J/min (7.5-11.8) and 8.3 J/min (6.6-10.2) in patients with and without PRF respectively. A higher MP during OLV was associated with PRF (ORadj 1.22 per 1 J/min increase; 95%CI 1.13-1.31; p < 0.001) and characterized by a U-shaped dose-response curve, with the lowest probability of PRF (7.5%) at 6.4 J/min. Dominance analysis of PRF predictors showed a stronger contribution of driving pressure over respiratory rate and tidal volume, the dynamic over the static component of MP, and MP during OLV over two-lung ventilation (contribution to Pseudo-R2: 0.017, 0.021, and 0.036, respectively).

CONCLUSION

A higher intensity of OLV, mainly driven by driving pressure, is dose-dependently associated with PRF and might constitute a target for mechanical ventilation.

Effect of perioperative goal-directed fluid therapy on postoperative complications after thoracic surgery with one-lung ventilation: a systematic review and meta-analysis

BACKGROUND

An understanding of the impact of goal-directed fluid therapy (GDFT) on the outcomes of patients undergoing one-lung ventilation (OLV) for thoracic surgery remains incomplete and controversial. This meta-analysis aimed to assess the effect of GDFT compared to other fluid therapy strategies on the incidence of postoperative complications in patients with OLV.

METHODS

The Embase, Cochrane Library, Web of Science, and MEDLINE via PubMed databases were searched from their inception to November 30, 2022. Forest plots were constructed to present the results of the meta-analysis. The quality of the included studies was evaluated using the Cochrane Collaboration tool and Risk Of Bias In Non-Randomized Study of Interventions (ROBINS-I). The primary outcome was the incidence of postoperative complications. Secondary outcomes were the length of hospital stay, PaO2/FiO2 ratio, total fluid infusion, inflammatory factors (TNF-α, IL-6), and postoperative bowel function recovery time.

RESULTS

A total of 1318 patients from 11 studies were included in this review. The GDFT group had a lower incidence of postoperative complications [odds ratio (OR), 0.47; 95% confidence interval (95% CI), 0.29-0.75; P = 0.002; I 2, 67%], postoperative pulmonary complications (OR 0.48, 95% CI 0.27-0.83; P = 0.009), and postoperative anastomotic leakage (OR 0.51, 95% CI 0.27-0.97; P = 0.04). The GDFT strategy reduces total fluid infusion.

CONCLUSIONS

GDFT is associated with lower postoperative complications and better survival outcomes after thoracic surgery for OLV.

A combination of supraglottic airway and bronchial blocker for one-lung ventilation in infants undergoing thoracoscopic surgery

Objectives

One-lung ventilation (OLV) for children under the age of two years is difficult. The authors hypothesize that a combination of a supraglottic airway (SGA) device and intraluminal placement of a bronchial blocker (BB) may provide an appropriate choice.

Design

A prospective method-comparison study.

Setting

Second Affiliated Hospital of Xi'an Jiaotong University, China.

Participants

120 patients under the age of two years undergoing thoracoscopic surgery with OLV.

Interventions

Participants were randomly assigned to receive intraluminal placement of BB with SGA (n = 60) or extraluminal placement of BB with endotracheal tube (ETT) (n = 60) for OLV.

Measurements and main results

The primary outcome was the length of postoperative hospitalization stay. The secondary outcomes were the basic parameters of OLV and investigator-defined severe adverse events. The postoperative hospitalization stay was 6 days (interquartile range, IQR 4-9) in SGA plus BB group compared with 9 days (IQR 6-13) in ETT plus BB group (P = 0.034). The placement and positioning duration of SGA plus BB was 64 s (IQR 51-75) compared with 132 s (IQR 117-152) of ETT plus BB (P = 0.001). The values of leukocyte (WBC) and C-reactive protein (CRP) of SGA plus BB group on the first day of post-operation were 9.8 × 10⁹/L (IQR 7.4-14.5) and 15.1 mg/L (IQR 12.5-17.3) compared with 13.6 × 10⁹/L (IQR 10.8-17.1) and 19.6 mg/L (IQR 15.0-23.5) of ETT plus BB group (P = 0.022 and P = 0.014).

Conclusion

There were few if any significant adverse events in the intervention group (SGA plus BB) for OLV in children under the age of two years, and this method seems worthy of clinical application. Meanwhile, the mechanism for this novel technique to shorten the length of postoperative hospitalization stay needs to be further explored.

Effect of one-lung ventilation on the correlation between left and right cerebral saturation

BACKGROUND

To investigate if the correlation between left and right cerebral tissue oxygen saturation (SctO₂) was affected by one-lung ventilation (OLV) in patients undergoing lung cancer surgery.

METHODS

Patients who underwent surgery for lung cancer were enrolled. Left and right SctO₂ were collected during anesthesia. The primary outcome was the correlation between left and right SctO₂ at 30 min after OLV which was analysed by Pearson correlation and linear regression model. Secondary outcomes included the trend of left-right SctO₂ change over the first 30 min after OLV, correlation of left-right SctO₂ during OLV for each patient; maximal difference between left-right SctO₂ and its relationship with postoperative delirium.

RESULTS

Left-right SctO₂ was moderately correlated at baseline (r = 0.690, P < 0.001) and poorly correlated at 30 min after OLV (r = 0.383, P < 0.001) in the Pearson correlation analysis. Linear regression analysis showed a poor correlation between left and right SctO₂ at 30 min after OLV (r = 0.323, P < 0.001) after adjusting for confounders. The linear mixed model showed a change in left-right SctO₂ over the first 30 min after OLV that was statistically significant (coefficient, -0.042; 95% CI, -0.070--0.014; P = 0.004). For the left-right SctO₂ correlation during OLV in each patient, 62.9% (78/124) patients showed a strong correlation, 19.4% (24/124) a medium correlation, and the rest a poor correlation. The maximal difference between the left and right SctO₂ was 13.5 (9.0, 20.0). Multivariate analysis showed that it was not associated with delirium (odds ratio [OR], 1.023; 95% CI, 0.963-1.087; P = 0.463).

CONCLUSIONS

The correlation between left and right SctO₂ was affected by one-lung ventilation in patients undergoing lung cancer surgery. This result indicates the requirement of bilateral SctO₂ monitoring to reflect brain oxygenation.

TRIAL REGISTRATION

This study was a secondary analysis of a cohort study approved by the Clinical Research Review Board of Peking University First Hospital (#2017-1378) and was registered in the Chinese Clinical Trial Registry on 10/09/2017 ( http://www.chictr.org.cn , ChiCTR-ROC-17012627).

The EZ-Blocker® for one-lung ventilation in a patient with Kartagener syndrome and tracheal bronchus -a case report

BACKGROUND

The tracheal bronchus in Kartagener syndrome is a rare case that may cause difficulty in one-lung ventilation (OLV). Here we reported a case of successful OLV using bronchial blocker in a patient with tracheal bronchus and Kartagener syndrome (KS).

CASE

A 66-year-old female patient with Kartagener syndrome was admitted for left-side diaphragmatic plication. The patient's preoperative computed tomography image showed a tracheal bronchus of the apical segment in the right upper lobe. The patient received epidural analgesia and general anesthesia through total intravenous anesthesia. An EZ-Blocker® (Teleflex Life Sciences Ltd., Ireland) was used to perform OLV.

CONCLUSIONS

OLV through an EZ-Blocker® can be successfully performed in tracheal bronchus patients with Kartagener syndrome without side effects.

Comparison of fiberoptic bronchoscopic intubation using silicone and polyvinyl chloride double-lumen tubes

Background

Direct insertion of a double-lumen tube (DLT) using a flexible fiberoptic bronchoscope (FOB) is an option for DLT intubation. The different properties of polyvinyl chloride and silicone DLTs may affect railroading differently, which is the difficult process of fiberoptic intubation. Therefore, we aimed to compare intubation using polyvinyl chloride and silicone DLTs over an FOB.

Methods

Patients aged 19-75 years who required one-lung ventilation under general anesthesia were enrolled in this study. After induction of anesthesia, the anesthesiologist intubated the DLT using FOB. The primary outcome was the difficulty of railroading over the flexible FOB scaled into five grades (I, II-1, II-2, III, and IV). Additionally, the intubation time and mucosal damage were recorded.

Results

A total of 46 patients participated in this study, 23 each in the silicone and polyvinyl groups. The difficulty of railroading over the FOB was significantly different between the two groups (P < 0.001). In the silicone group, the grades of difficulty in railroading were limited to I and II-1; 20 patients (87%) presented no difficulty in advancing the tube. In contrast, in the polyvinyl group, 13 patients (57%) had scores of II-2 and III. Both the intubation time and mucosal damage were significantly better in the silicone group than in the polyvinyl group.

Conclusions

Intubation using a silicone DLT over an FOB was easier and faster than that with a polyvinyl chloride DLT with lesser trauma around the glottis.

Comparative study of a modified double-lumen tube ventilation control connector and traditional connector in clinical use: a randomised-controlled trial

Background

A Y-shaped rotatable connector (YRC) for double-lumen tubes (DLT) is invented and compared with the traditional connector (Y-shaped connector, YC).

Methods

Sixty patients with ASA grade I-III, aged ≥ 18 years, who needed to insert a DLT for thoracic surgery were recruited and assigned into the YRC group (n = 30) and the YC group (n = 30) randomly. The primary endpoints included the inhaled air concentration (Fi) and the exhaled air concentration (Et) of sevoflurane before and after the switch between two-lung ventilation and one-lung ventilation at different times, positioning time, and switching time. The secondary endpoints were the internal gas volume of the two connectors, airway pressure, and the sputum suction time.

Results

The Et and Fi of the YRC group and the YC group were significantly different (all p < 0.05) at 5s, 10s, and 30s after the patient switched from two-lung ventilation to one-lung ventilation. The positioning time of the YRC group was less than YC group (89.75 ± 14.28 s vs 107.80 ± 14.96 s, p < 0.05), as well as the switching time (3.60 ± 1.20 s vs 9.05 ± 2.53 s, p < 0.05) and the internal gas volume (17.20 ml vs 24.12 ml). There was no difference in airway pressure and the sputum suction time in two groups.

Conclusion

Compared with YC, YRC was beneficial for maintaining depth of anesthesia, improves efficiency for the switch between one-lung and two-lung ventilation, and shortens the tube positioning time.

1. YRC was beneficial to maintain the stability of anesthesia depth.

2. YRC improves the conversion efficiency for one-lung and two-lung ventilation.

3. YRC shortens the positioning time.

[Application and Research Progress of Video Double-lumen Tube in Thoracic Surgery]

The rapid development and promotion of minimally invasive thoracic surgery represented by video-assisted thoracoscopy surgery has gradually replaced traditional thoracic surgery technique as the primary choice for the treatment of pulmonary nodules, including early lung cancer. With the clinical application of double-lumen bronchial catheters, the realization of one-lung ventilation technology not only provides a solid anesthesia foundation for the popularization of minimally invasive thoracic surgery, but also provides a guarantee for the rapid and smooth implementation of the operation. However, compared with single-lumen bronchial catheters, the diameter of the double-lumen bronchial catheter is thicker, and the tube body is hard and difficult to shape, which brings inconvenience to anesthesia intubation. The bronchial structure is different, and the incidence of dislocation during anesthesia intubation is also high. With the gradual clinical use of video double-lumen tube (VDLT), it has become a hot spot in thoracic surgery in recent years. This article reviews the application and research progress of VDLT in thoracic surgery.
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Two-lung ventilation in video-assisted thoracoscopic esophagectomy in prone position: A systematic review

Esophageal cancer surgery is still carrying a high risk of morbidity and mortality. That is why some anesthesia strategies have tried to reduce those postoperative complications. In this systematic review performed in accordance with the PRISMA-S guidelines (PROSPERO (ID: CRD42022310385)), we aimed to investigate the safety and advantages of two-lung ventilation (TLV) over one-lung ventilation (OLV) in minimally invasive esophagectomy (MIE) in the prone position. Seven trials, with a total number of 1710 patients (765 patients with TLV versus 945 patients with OLV) were included. Postoperative mortality and morbidity rates were similar between TLV and OLV when realised for esophagectomy. Interestingly, we observed no difference in changes in intraoperative respiratory parameters, operative duration, thoraco-conversion rate, number of harvested lymph nodes, postoperative heart rate and respiratory rate between TLV and OLV. TLV brings better results in terms of intraoperative oxygen arterial pressure (PaO₂) during the thoracic time, postoperative oxygenation, PaO2 on inspired fraction of oxygen (FiO₂) ratio, duration of thoracic surgery, preoperative time, blood loss, temperature on postoperative day-1, and C-reactive protein dosage. Our study highlighted the safety of TLV for MIE in prone position when compared to OLV. Interestingly, we found better intra and postoperative ventilation parameters. The choice of ventilation modality did not influence clinical outcome after surgery and the quality of oncological resection. Large randomised controlled trials are needed to confirm these results.

Lung ultrasound is non-inferior to bronchoscopy for confirmation of double-lumen endotracheal tube positioning: a randomized controlled noninferiority study

BACKGROUND

Appropriate placement of left-sided double-lumen endotracheal tubes (LDLTs) is paramount for optimal visualization of the operative field during thoracic surgeries that require single lung ventilation. Appropriate placement of LDLTs is therefore confirmed with fiberoptic bronchoscopy (FOB) rather than clinical assessment alone. Recent studies have demonstrated lung ultrasound (US) is superior to clinical assessment alone for confirming placement of LDLT, but no large trials have compared US to the gold standard of FOB. This noninferiority trial was devised to compare lung US with FOB for LDLT positioning and achievement of lung collapse for operative exposure.

METHODS

This randomized, controlled, double-blind, noninferiority trial was conducted at the Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand from October 2017 to July 2019. The study enrolled 200 ASA classification 1-3 patients that were scheduled for elective thoracic surgery requiring placement of LDLT. Study patients were randomized into either the FOB group or the lung US group after initial blind placement of LDLT. Five patients were excluded due to protocol deviation. In the FOB group (n = 98), fiberoptic bronchoscopy was used to confirm lung collapse due to proper positioning of the LDLT, and to adjust the tube if necessary. In the US group (n = 97), lung ultrasonography of four pre-specified zones (upper and lower posterior and mid-axillary) was used to assess lung collapse and guide adjustment of the tube if necessary. The primary outcome was presence of adequate lung collapse as determined by visual grading by the attending surgeon on scale from 1 to 4. Secondary outcomes included the time needed to adjust and confirm lung collapse, the time from finishing LDLT positioning to the grading of lung collapse, and intraoperative parameters such has hypotension or hypertension, hypoxia, and hypercarbia. The patient, attending anesthesiologist, and attending thoracic surgeon were all blinded to the intervention arm.

RESULTS

The primary outcome of lung collapse by visual grading was similar between the intervention and the control groups, with 89 patients (91.8%) in the US group compared to 83 patients (84.1%) in the FOB group (p = 0.18) experiencing adequate collapse. This met criteria for noninferiority per protocol analysis. The median time needed to confirm and adjust LDLT position in the US group was 3 min (IQR 2-5), which was significantly shorter than the median time needed to perform the task in the FOB group (6 min, IQR 4-10) (p = 0.002).

CONCLUSIONS

In selected patients undergoing thoracic surgery requiring LDLT, lung ultrasonography was noninferior to fiberoptic bronchoscopy in achieving adequate lung collapse and reaches the desired outcome in less time.

TRIAL REGISTRATION

This study was registered at clinicaltrials.gov, NCT03314519 , Principal investigator: Kasana Raksamani, Date of registration: 19/10/2017.

Peroxiredoxin 6 mediates the protective function of curcumin pretreatment in acute lung injury induced by serum from patients undergoing one-lung ventilation in vitro

Background

Curcumin has attracted much attention due to its wide range of therapeutic effects. In this study, we used serum collected from patients undergoing one-lung ventilation (OLV) to establish an in vitro acute lung injury (ALI) model to explore the potential protective mechanism of curcumin on ALI. Our study provides a new reference for the prevention and treatment of ALI induced by OLV.

Methods

A549 cells were treated with 20% serum from patients undergoing OLV to establish an in vitro ALI model. Curcumin, at a dose of 40 μg/ml, was administered two hours prior to this model. The levels of inflammation and oxidative stress markers were observed by Western blot, qRT–PCR, ELISA and reactive oxygen species assay. Additionally, the expression of peroxiredoxin 6 (Prdx6) and proteins involved in the NF-κB signaling pathway was evaluated.

Results

Twenty percent of serum collected from patients undergoing OLV downregulated the expression of Prdx6, leading to the activation of the NF-κB signaling pathway, which was associated with the subsequent overproduction of inflammatory cytokines and reactive oxygen species. Pretreatment with curcumin restored Prdx6 downregulation and inhibited NF-κB pathway activation by suppressing the nuclear translocation of P65, eventually reducing inflammation and oxidative stress damage in A549 cells.

Conclusions

Prdx6 mediated the protective function of curcumin by inhibiting the activation of the NF-κB pathway in ALI in vitro.

Clinical guide to perioperative management for videothoracoscopy lung resection (Section of Cardiac, Vascular and Thoracic Anesthesia, SEDAR; Spanish Society of Thoracic Surgery, SECT; Spanish Society of Physiotherapy)

The introduction of video-assisted thoracoscopic (VATS) techniques has led to a new approach in thoracic surgery. VATS is performed by inserting a thoracoscope through a small incisions in the chest wall, thus maximizing the preservation of muscle and tissue. Because of its low rate of morbidity and mortality, VATS is currently the technique of choice in most thoracic procedures. Lung resection by VATS reduces prolonged air leaks, arrhythmia, pneumonia, postoperative pain and inflammatory markers. This reduction in postoperative complications shortens hospital length of stay, and is particularly beneficial in high-risk patients with low tolerance to thoracotomy. Compared with conventional thoracotomy, the oncological results of VATS surgery are similar or even superior to those of open surgery. This aim of this multidisciplinary position statement produced by the thoracic surgery working group of the Spanish Society of Anesthesiology and Reanimation (SEDAR), the Spanish Society of Thoracic Surgery (SECT), and the Spanish Association of Physiotherapy (AEF) is to standardize and disseminate a series of perioperative anaesthesia management guidelines for patients undergoing VATS lung resection surgery. Each recommendation is based on an in-depth review of the available literature by the authors. In this document, the care of patients undergoing VATS surgery is organized in sections, starting with the surgical approach, and followed by the three pillars of anaesthesia management: preoperative, intraoperative, and postoperative anaesthesia.

Desflurane improves lung collapse more than propofol during one-lung ventilation and reduces operation time in lobectomy by video-assisted thoracic surgery: a randomized controlled trial

Background

This study evaluated whether desflurane improved lung collapse during one-lung ventilation (OLV) more than propofol, and whether it could reduce the operation time of video-assisted thoracic surgery.

Methods

Sixty patients undergoing lobectomy by video-assisted thoracic surgery (VATS) were randomly assigned to general anesthesia with desflurane or propofol. Lungs were inspected by thoracoscope at 10, 30, and 60 min after initiation of OLV. After surgery, the Lung Collapse Score, a composite of lung color and volume assessments, was assigned by two clinicians blinded to the anesthetic regimen. The primary outcome was operation time. The secondary outcome included the complication rate.

Results

Of the 60 participants, 50 completed the study, 26 in Desflurane group and 24 in Propofol group. The Lung Collapse Scores at 30 and 60 min after OLV initiation were significantly better in Desflurane group than in Propofol group, and operation time was significantly shorter in Desflurane group (214 (57) min vs. 262 (72) min [mean (SD)], difference in means, -48; 95% CI, -85 to -11; P = 0.01). The incidence of multiple complications was 1/26 (3%) and 6/24 (25%) in Desflurane and Propofol group, respectively (relative risk, 0.1; 95% CI, 0.02 to 1.18; P = 0.04).

Conclusions

Desflurane improved lung collapse during OLV and significantly shortened VATS lobectomy operation time compared to propofol in our studied patients. Desflurane resulted in fewer postoperative complications. Thus, desflurane may be an appropriate anesthetic during lobectomy by VATS requiring OLV.

Trial registration

The study was registered with the University Hospital Medical Information Network (UMIN000009412). The date of disclosure of this study information is 27/11/2012. On this date, we registered the study into UMIN; patients were included from 2013 to 2014. However, on 11/27/2015, the UMIN system administrator suggested a detailed description. Thereafter, we added it to the Randomization Unit. Despite being prospective, it was retrospectively registered on UMIN for the above reasons.

Double-lumen tube versus bronchial blocker in lymphadenectomy along the left recurrent laryngeal nerve for esophageal cancer: a propensity-matched analysis

BACKGROUND

Lymph node (LN) dissection along left recurrent laryngeal nerve (RLN) is challenging in esophagectomy for esophageal cancer, and double-lumen endotracheal tube (DLT) impedes the exposure of this area. The aim of this study was to determine whether bronchial blockers (BB) could be a better choice for this procedure.

METHODS

The clinical characteristics of patients who received McKeown esophagectomy with radical lymph node dissection in Wuhan Tongji Hospital between August 2017 and July 2019 were retrospectively analyzed. The 1:1 propensity score match analysis was performed to compare the short-term effectiveness, the numbers of lymph nodes dissected, and the patterns of recurrence and survival between the two groups.

RESULTS

A total of 294 patients (192 and 102 in the DLT and BB group, respectively) were enrolled in the study. After matching, 204 patients (102 pairs) who underwent one-lung ventilation with DLT or BB displayed no significant variance in baseline characteristics. The BB group had higher number of LNs resected along left RLN (1.8 ± 2.3 vs. 2.5 ± 2.5, P = 0.001). For patients with metastatic left RLN LN, the BB group had longer medium survival time (15 vs. 32 months, P = 0.045), and tended to have longer medium recurrence-free survival time (6 vs. 15 months, P = 0.079), and lower rate of upper mediastinal and cervical LN recurrence (30.00% vs. 66.67%, P = 0.198). The postoperative complications were similar in both groups.

CONCLUSIONS

Compared with DLT, using BB in esophagectomy may allow more radical lymphadenectomy along left RLN.

One-lung ventilation using a laryngeal mask airway and bronchial blocker in a patient with vocal cord cancer: a case report

Background

One-lung ventilation is a standard technique for thoracic anesthesia. Usually, one-lung ventilation requires a large-bore tracheal tube. Therefore, in patients with vocal cord morbidity, it is challenging to achieve one-lung ventilation while preventing the damage of vocal cord lesions.

Case presentation

A 77-year-old man was diagnosed with vocal cord cancer and lung tumor. One-lung ventilation with a combination of a laryngeal mask airway and bronchial blocker was planned to avoid unexpected vocal cord injury. After securing the airway with a laryngeal mask airway, a bronchial blocker was placed under fiberscope guidance. The bronchial blocker passed through a position far enough from the vocal cord lesion. The bronchial blocker provided a clear view of the operative field. The patient’s perioperative course was uneventful.

Conclusions

When one-lung ventilation is required for patients with vocal cord lesions, a combination of a laryngeal mask airway and bronchial blocker is considered a good option.

Two-lung ventilation or one-lung ventilation for esophagectomy: maybe the more is better from the evidence of meta-analysis

One-lung ventilation (OLV) is the most commonly used ventilation strategy during esophagectomy. However, two-lung ventilation (TLV) with artificial pneumothorax has been applied in recent years during esophagectomy. It is unclear whether TLV takes advantages over OLV for esophagectomy. Here, we conducted a meta-analysis to compare the effects of TLV and OLV for esophagectomy. We searched relevant studies from the Cochrane Central Register of Controlled Trials, Pubmed, and Embase in November 2020. We included studies that compared the effects of TLV with OLV in esophagectomy and provided sufficient perioperative and postoperative data. We extracted data of postoperative outcomes (postoperative pulmonary complications, anastomotic leak, hospital stay) and surgical variables (thoracic phrase time, blood loss, the number of total resected thoracic lymph nodes). We calculated the risk ratio (RR) for dichotomous data and the weighted mean differences (WMDs) for continuous data. Six studies with 1725 patients were included in this meta-analysis. TLV was associated with significantly lower incidence of postoperative pulmonary complications [RR = 0.714; 95% confidence interval (CI) = (0.534, 0.956); P = 0.023], shorter hospital stay [WMD =  - 0.148; 95% CI = (- 0.246, - 0.051); P = 0.003], less blood loss [WMD =  - 0.352; 95% CI = (- 0.528, - 0.176); P < 0.001] and more resected thoracic lymph nodes [WMD = 0.207; 95% CI = (0.003, 0.4120); P = 0.047] than OLV. Moreover, TLV consumed similar time for thoracic phrase [WMD =  - 0.289; 95% CI = (- 0.661, 0.083); P = 0.128], and yielded a comparable rate of anastomotic leak [RR = 1.086; 95% CI = (0.842, 1.400); P = 0.525] compared with OLV. TLV with artificial pneumothorax resulted in less trauma than OLV. TLV with artificial pneumothorax is safe and could be a choice of ventilation strategy for esophagectomy.

Unilateral pulmonary edema associated factors after minimally invasive mitral valve surgery

BACKGROUND AND OBJECTIVES

In recent years, minimally invasive cardiac surgery (MICS) has been developed and applied to a greater number of pathologies, especially in mitral valve surgeries, as it obtains results comparable to those of conventional techniques while entailing lower surgical trauma and shorter recovery time. MICS requiring one-lung ventilation has been associated to the appearance of unilateral pulmonary edema (UPE), which is a potentially serious complication. The objective is determining the incidence of UPE after mitral MICS and its development associated factors.

MATERIAL AND METHODS

Observational descriptive and single-center study analyzing data from patients undergoing mitral valve MICS (right mini-thoracotomy) consecutively collected between the years 2015 and 2017.

RESULTS

A total of 93 patients were included and 26 presented UPE. The most common complications after mitral valve MICS were atrial fibrillation (38.7%), UPE (28%) and transient and/or definitive second- or third-degree auriculoventricular block (19.4%). The UPE group had longer ICU stay (3.3 ± 8.0 vs. 1.84 ± 2.23 days) and longer total hospitalization length-of-stay (15.5 ± 34.7 vs. 10.6 ± 7.5 days). The mortality in the UPE group was 3.9%. A significant association was found between the following collected variables and the development of postoperative UPE: preoperative baseline pulse oximetry, preoperative use of ACE inhibitors, postoperative atrial fibrillation and 24 first-hours cumulative chest tube drainage volume on the first 24 h.

CONCLUSIONS

The incidence of UPE is high and its appearance is associated with a longer ICU and total length of stay. More studies are required to understand its pathophysiology and apply measures to help decreasing its appearance.

Comparison of two-lung and one-lung ventilation in bilateral video-assisted thoracoscopic extended thymectomy in myasthenia gravis: a retrospective study

Background

Myasthenia gravis (MG) is an autoimmune disease, and early thymectomy is recommended. Since the introduction of video-assisted thoracoscopic surgery, the safety and effectiveness of carbon dioxide insufflation in the thoracic cavity (capnothorax) has been controversial. This study aimed to compare the safety and effectiveness of ventilation methods in bilateral video-assisted thoracoscopic extended thymectomy (BVET) with capnothorax.

Methods

We retrospectively investigated the medical records of patients with MG who underwent BVET between August 2016 and January 2018. Patients were divided into two groups: group D (n = 26) for one-lung ventilation and group S (n = 28) for two-lung ventilation. We set nine anesthesia time points (T0–T8) and collected respiratory and hemodynamic variables, including arterial O₂ index (PaO₂/FiO₂).

Results

SpO₂ at T1–T3 and T8 was significantly lower in group D than in group S. The FiO₂ in group S was lower than that in group D at all time points. The number of PaO₂/FiO₂ ≤ 300 and PaO₂/FiO₂ ≤ 200 events was significantly higher in group D than in group S. Hemodynamic variables were not significantly different between the two groups at any time point. The duration of surgery and anesthesia was shorter in group S than in group D.

Conclusions

This retrospective study suggests that anesthesia using two-lung ventilation during BVET with capnothorax is a safe and effective method to improve lung oxygenation and reduce anesthesia time.

Anesthesia for thoracic surgery in infants and children

The management of infants and children presenting for thoracic surgery poses a variety of challenges for anesthesiologists. A thorough understanding of the implications of developmental changes in cardiopulmonary anatomy and physiology, associated comorbid conditions, and the proposed surgical intervention is essential in order to provide safe and effective clinical care. This narrative review discusses the perioperative anesthetic management of pediatric patients undergoing noncardiac thoracic surgery, beginning with the preoperative assessment. The considerations for the implementation and management of one-lung ventilation (OLV) will be reviewed, and as will the anesthetic implications of different surgical procedures including bronchoscopy, mediastinoscopy, thoracotomy, and thoracoscopy. We will also discuss pediatric-specific disease processes presenting in neonates, infants, and children, with an emphasis on those with unique impact on anesthetic management.

Current practice of thoracic anaesthesia in Europe - a survey by the European Society of Anaesthesiology Part I - airway management and regional anaesthesia techniques

Background

The scientific working group for “Anaesthesia in thoracic surgery” of the German Society of Anaesthesiology and Intensive Care Medicine (DGAI) has performed an online survey to assess the current standards of care and structural properties of anaesthesia workstations in thoracic surgery.

Methods

All members of the European Society of Anaesthesiology (ESA) were invited to participate in the study.

Results

Thoracic anaesthesia was most commonly performed by specialists/board-certified anaesthetists and/or senior/attending physicians. Across Europe, the double lumen tube (DLT) was most commonly chosen as the primary device for lung separation (461/ 97.3%). Bronchial blockers were chosen less frequently (9/ 1.9%).

Throughout Europe, bronchoscopy was not consistently used to confirm correct double lumen tube positioning. Respondents from Eastern Europe (32/ 57.1%) frequently stated that there were not enough bronchoscopes available for every intrathoracic operation. A specific algorithm for difficult airway management in thoracic anaesthesia was available to only 18.6% (n = 88) of the respondents. Thoracic epidural analgesia (TEA) is the most commonly used form of regional analgesia for thoracic surgery in Europe. Ultrasonography was widely available 93,8% (n = 412) throughout Europe and was predominantly used for central line placement and lung diagnostics.

Conclusions

While certain „gold standards “are widely met, there are also aspects of care requiring substantial improvement in thoracic anaesthesia throughout Europe.

Our data suggest that algorithms and standard operating procedures for difficult airway management in thoracic anaesthesia need to be established. A European recommendation for the basic requirements of an anaesthesia workstation for thoracic anaesthesia is expedient and desirable, to improve structural quality and patient safety.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01480-w.

Effect of desflurane on changes in regional cerebral oxygenation in patients undergoing one-lung ventilation is equivalent to the effect of propofol

OBJECTIVES

Desaturation is an important clinical problem during one-lung ventilation (OLV) since it may induce cerebral hypoxia. Measurement of cerebral oxygenation has been shown to provide accurate information about episodes of cerebral hypoxemia. The purpose of this study was to compare the effect of desflurane on changes in cerebral oxygenation during OLV with the effect of propofol.

METHODS

A randomized, single-blinded, prospective study was conducted. Fifty adult patients who were scheduled to undergo thoracic surgery were randomly assigned to anesthetic management using desflurane with remifentanil (Group D: n = 25) or using propofol and remifentanil (Group P: n = 25).

RESULTS

The characteristics of the patients were very similar. Intergroup analysis of changes in cerebral oxygenation showed no significant difference on the operative side (two-way ANOVA, F (7, 368) = 0.425, p = 0.887) or the non-operative side (two-way ANOVA, F (7, 367) = 1.342, p = 0.229). Intragroup analysis of changes in cerebral oxygenation using one-way ANOVA showed no significant difference on the operative side (Group P; p = 0.585, Group D; p = 0.928) or the non-operative side in both groups (Group P; p = 0.657, Group D; p = 0.602).

CONCLUSIONS

The effects of desflurane and propofol on changes in cerebral oxygenation in patients undergoing OLV were equivalent. Our results indicated that desflurane might be an appropriate anesthetic during OLV for maintaining cerebral oxygenation with an effective equivalent to that of propofol.

Anesthetic management during whole-lung lavage using lung ultrasound in a patient with pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is an uncommon disease characterized by progressive accumulation of lipoprotein material in the lungs due to impaired surfactant clearance. Whole-lung lavage (WLL) is the current standard treatment and consists of sequential lavage of each lung to mechanically remove the residual material from the alveoli. Although WLL is considered safe, unexpected complications can occur. Moreover, due to the rarity of the disease itself, this procedure is unknown to many physicians, and management of intraoperative complications can be challenging for anesthesiologists. Lung ultrasound (LUS) provides reliable and valuable information for detecting perioperative pulmonary complications and, in particular, quantitation of lung water content. There have been reports on monitoring the different stages of controlled deaeration of the non-ventilated lung during WLL using LUS. However, it has been limited to non-ventilated lungs. Therefore, we report the use of LUS in WLL to proactively detect pulmonary edema in the ventilated lung and implement a safe and effective anesthesia strategy. Given the limited diagnostic tools available to anesthesiologists in the operating room, LUS is a reliable, fast, and noninvasive method for identifying perioperative pulmonary complications in patients with PAP undergoing WLL.

Awake fiberoptic intubation and use of bronchial blockers in ankylosing spondylitis patients

BACKGROUND

Patients with ankylosing spondylitis (AS) combined with severe cervical fusion deformity have difficult airways. Awake fiberoptic intubation is the standard treatment for such patients. Alleviating anxiety and discomfort during intubation while maintaining airway patency and adequate ventilation is a major challenge for anesthesiologists. Bronchial blockers (BBs) have significant advantages over double-lumen tubes in these patients requiring one-lung ventilation.

AIM

To evaluate effective drugs and their optimal dosage for awake fiberoptic nasotracheal intubation in patients with AS and to assess the pulmonary isolation effect of one-lung ventilation with a BB.

METHODS

We studied 12 AS patients (11 men and one woman) with lung or esophageal cancer who underwent thoracotomy with a BB. Preoperative airway evaluation found that all patients had a difficult airway. All patients received an intramuscular injection of penehyclidine hydrochloride (0.01 mg/kg) before anesthesia. In the operating room, dexmedetomidine(0.5 μg/kg) was infused intravenously for 10 min, with 2% lidocaine for airway surface anesthesia, and a 3% ephedrine cotton swab was used to contract the nasal mucosa vessels. Before tracheal intubation, fentanyl (1 μg/kg) and midazolam (0.02 mg/kg) were administered intravenously. Awake fiberoptic nasotracheal intubation was performed in the semi-reclining position. Intravenous anesthesia was administered immediately after successful intubation, and a BB was inserted laterally. The pre-intubation preparation time, intubation time, facial grimace score, airway responsiveness score during the fiberoptic introduction, time of end tracheal catheter entry into the nostril, and lung collapse and surgical field score were measured. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were recorded while entering the operation room (T1), before intubation (T2), immediately after intubation (T3), 2 min after intubation (T4), and 10 min after intubation (T5). After surgery, all patients were followed for adverse reactions such as epistaxis, sore throat, hoarseness, and dysphagia.

RESULTS

All patients had a history of AS (20.4 ± 9.6 years). They had a Willson's score of 5 or above, grade III or IV Mallampati tests, an inter-incisor distance of 2.9 ± 0.3 cm, and a thyromental (T-M) distance of 4.8 ± 0.7 cm. The average pre-intubation preparation time was 20.4 ± 3.4 min, intubation time was 2.6 ± 0.4 min, facial grimace score was 1.7 ± 0.7, airway responsiveness score was 1.1 ± 0.7, and pulmonary collapse and surgical exposure score was 1.2 ± 0.4. The SBP, DBP, and HR at T5 were significantly lower than those at T1-T4 (P < 0.05). While the values at T1 were not significantly different from those at T2-T4 (P > 0.05), they were significantly different from those at T5 (P < 0.05). Seven patients had minor epistaxis during endotracheal intubation, two were followed 24 h after surgery with a mild sore throat, and two had hoarseness without dysphagia.

CONCLUSION

Patients with AS combined with severe cervical and thoracic kyphosis should be intubated using fiberoptic bronchoscopy under conscious sedation and topical anesthesia. Proper doses of penehyclidine hydrochloride, dexmedetomidine, fentanyl, and midazolam, combined with 2% lidocaine, administered prior to intubation, can provide satisfactory conditions for tracheal intubation while maintaining the comfort and safety of patients. BBs are safe and effective for one-lung ventilation in such patients during thoracotomy.

Clinical guide to perioperative management for videothoracoscopy lung resection (Section of Cardiac, Vascular and Thoracic Anesthesia, SEDAR; Spanish Society of Thoracic Surgery, SECT; Spanish Society of Physiotherapy)

The introduction of video-assisted thoracoscopic (VATS) techniques has led to a new approach in thoracic surgery. VATS is performed by inserting a thoracoscope through a small incisions in the chest wall, thus maximizing the preservation of muscle and tissue. Because of its low rate of morbidity and mortality, VATS is currently the technique of choice in most thoracic procedures. Lung resection by VATS reduces prolonged air leaks, arrhythmia, pneumonia, postoperative pain and inflammatory markers. This reduction in postoperative complications shortens hospital length of stay, and is particularly beneficial in high-risk patients with low tolerance to thoracotomy. Compared with conventional thoracotomy, the oncological results of VATS surgery are similar or even superior to those of open surgery. This aim of this multidisciplinary position statement produced by the thoracic surgery working group of the Spanish Society of Anesthesiology and Reanimation (SEDAR), the Spanish Society of Thoracic Surgery (SECT), and the Spanish Association of Physiotherapy (AEF) is to standardize and disseminate a series of perioperative anaesthesia management guidelines for patients undergoing VATS lung resection surgery. Each recommendation is based on an in-depth review of the available literature by the authors. In this document, the care of patients undergoing VATS surgery is organized in sections, starting with the surgical approach, and followed by the three pillars of anaesthesia management: preoperative, intraoperative, and postoperative anaesthesia.

Anesthetic Management for Thoracic Surgery During the COVID-19 Pandemic

Purpose of Review

This review explores recent international guidance on the anesthetic management of patients undergoing thoracic surgery during the COVID-19 pandemic: those with suspected or confirmed COVID-19 requiring urgent thoracic surgery and those presenting for elective procedures.

Recent Findings

A significant mortality risk is associated with patients with COVID-19 undergoing thoracic surgery; therefore, where possible, it should be avoided. Thoracic surgery also carries a significant risk of viral transmission to healthcare workers due to the necessarily high frequency of intraoperative aerosol-generating procedures involved, such as lung isolation, one-lung ventilation, and flexible bronchoscopy.

Summary

Guidelines recommend appropriate personal protective equipment and numerous procedural modifications to prevent viral transmission to staff and other patients. With appropriate disease mitigation strategies in place, elective thoracic surgery, in particular for lung cancer, has been able to continue safely in many centres.

Hypoxemia During One-Lung Ventilation: Does It Really Matter?

Purpose of Review

Hypoxemia during one-lung ventilation, while decreasing in frequency, persists as an intraoperative challenge for anesthesiologists. Discerning when desaturation and resultant hypoxemia correlates to tissue hypoxia is challenging in the perioperative setting and requires a thorough understanding of the physiology of oxygen delivery and tissue utilization.

Recent Findings

Oxygen delivery is not directly correlated with peripheral oxygen saturation in patients undergoing one-lung ventilation, emphasizing the importance of hemoglobin concentration and cardiac output in avoiding tissue hypoxia. While healthy humans can tolerate acute hypoxemia without long-term consequences, there is a paucity of evidence from patients undergoing thoracic surgery. Increasingly recognized is the potential harm of hyperoxic states, particularly in the setting of complex patients with comorbid diseases.

Summary

Anesthesiologists are left to determine an acceptable oxygen saturation nadir that is individualized to the patient and procedure based on an understanding of oxygen supply, demand, and the consequences of interventions.

Contralateral tension pneumothorax during video-assisted thoracic surgery for lung cancer in a patient with obesity and rib fractures: a case report and review of the literature

Background

Intraoperative contralateral pneumothorax during one-lung ventilation is a rare but life-threatening complication. Although the exact incidence is unknown, only 14 cases with this complication have been reported until now.

Case presentation

A 67-year-old Japanese man with a weight of 80 kg, height of 162.2 cm, and body mass index of 30.4 kg/m² underwent three-port video-assisted thoracic surgery for lung cancer with one-lung ventilation. He had suffered from traumatic right rib fractures 6 weeks before the referral. Fifteen minutes before the end of the surgery, the systolic blood pressure suddenly dropped to about 50 mmHg, which was immediately recovered by intravenous injection of phenylephrine. This episode occurred during chest closure after the completion of the left upper lobectomy, and one-lung ventilation was soon switched to two-lung ventilation. Contralateral tension pneumothorax was noted by the postoperative chest x-ray. As the patient was complicated with obesity and a past history of rib fractures, increased airway pressure during one-lung ventilation related to obesity together with the persistent compression of the visceral pleura by the fractured ends of the ribs was considered to be the factors responsible for this critical complication.

Conclusions

Patient backgrounds such as obesity and past history of rib fractures should be noted carefully as risk factors for intraoperative contralateral pneumothorax during one-lung ventilation. We present the clinical course and discuss the mechanism of development of this potentially life-threatening complication in the present case with a review of the literature.

A nationwide survey of intraoperative management for one-lung ventilation in Taiwan: time to accountable for diversity in protective lung ventilation

BACKGROUND

There is a major paradigm shift for intraoperative mechanical ventilator support by the introduction of lung protective ventilation strategies to reduce postoperative pulmonary complications and improve overall clinical outcomes in non-thoracic surgeries. However, there is currently a lack of standardized practice guideline for lung protection during thoracic surgeries that require one-lung ventilation (OLV). This study aimed to collect the expert opinions of the thoracic anesthesiologists in perioperative care for OLV surgery in Taiwan.

METHODS

This prospective cross-sectional study was undertaken in 16 tertiary hospitals in Taiwan from January to February 2019. A structured survey form was distributed across the participating hospitals and the thoracic anesthesiologists were invited to complete the form voluntarily. The survey form consisted of three parts, including the basic information of the institutional anesthesia care standards, ventilatory settings for a proposed patient receiving OLV surgery and expert opinions on OLV.

RESULTS

A total of 71 thoracic anesthesiologists responded to the survey. Double-lumen tubes are the most commonly used (93.8%) airway devices for OLV. The most commonly recommended ventilator setting during OLV is a tidal volume of 6-7 ml/kg PBW (67.6%) and a PEEP level of 4-6 cmH₂O (73.5%). Dual controlled ventilator modes are used by 44.1% of the anesthesiologists. During OLV, high oxygen fraction (FiO₂ > 0.8) is more commonly supplemented to achieve an oxygen saturation higher than 94%. The consensus of anesthesiologists on the indices for lung protection in thoracic surgery is considerably low. Large majority of the anesthesiologists (91.5%) highly recommend that an international clinical practice guideline on the protective lung ventilation strategy for thoracic anesthesia should be established.

CONCLUSIONS

This study found that the thoracic anesthesiologists in Taiwan share certain common practices in ventilator support during OLV. However, they are concerned about the lack of fundamental clinical evidences to support the beneficial outcomes of the current lung protective strategies applicable to OLV. Large-scale trials are needed to form an evidence-based clinical practice guideline for thoracic anesthesia.

A special double lumen tube for use in pigs is suitable for different lung ventilation conditions

Previous studies of haemodynamic and blood gas variables during one-lung ventilation in pigs have used a double lumen tube designed for use in humans. However, because of interspecies differences in bronchial anatomy, a special design for pigs is required. In this study, we evaluated a new left-sided double lumen endobronchial tube designed for use in pigs under different lung ventilation conditions. Ten female pigs (weighing 35-40 kg) were transorally intubated, first with a single lumen tube and then with the left-sided double lumen tube for pigs, and mechanically ventilated. Haemodynamic and blood gas variables were recorded before and after intubation with the double lumen tube and before and after one-lung flooding of the left lung with saline solution. Each pig was repositioned (left lateral, to dorsal, to right lateral) every 30 min during one-lung flooding. Bronchoscopy and thoracic radiography were performed at fixed intervals. Blood gas variables during two-lung ventilation were not impaired by intubation with the double lumen endobronchial tube for pigs, compared with intubation with the single lumen tube. Haemodynamic and blood gas variables were not impaired by one-lung flooding. Complete flooding of the left lung was achieved for all pigs. Two-lung ventilation to reventilate the previously flooded lung provided complete air filling for all pigs. Use of this tube resulted in lung separation without obstruction of bronchi or resultant atelectasis. In this study, the new double lumen tube for pigs was safe for one-lung flooding and prevented fluid entry into the non-flooded lung.

Efficacy of Automatic Retention Pressure of a Double-Lumen Tube Cuff: An Artificial Intubation Model

BACKGROUND

The movement of a double-lumen endotracheal tube (DLT) out of its appropriate position during thoracic surgery can result in the loss of one-lung ventilation (OLV), especially during pulmonary resection and node dissection. Our study aimed to validate the efficacy of automatic retention pressure control of the DLT bronchial cuff in maintaining OLV in an artificial intubation model.

MATERIALS AND METHODS

A 35-Fr left-sided DLT was intubated to the left main bronchus in an intubation simulator and connected to an anesthesia machine. The inspiratory volume, respiratory rate, and inspiratory-expiratory ratio were set at 500 mL, 12 times/min, and 1:2, respectively. A 1-kg right main bronchial traction in the lateral right was provided after OLV was established. SmartCuff (Smiths Medical, Minneapolis, Minnesota, USA) was used to maintain cuff pressure. The efficacy of retention pressure with SmartCuff (Group S) and without SmartCuff (Group WS) was compared. The primary outcome was the rate of tidal volume (TV) reduction following bronchial traction in the two groups.

RESULTS

The TVs were 289.8 ± 28.9 mL and 242.8 ± 31.9 mL in Group S and Group WS, respectively (P = 0.003). The rate of TV reduction after bronchial traction was significantly lower in Group S (29 ± 5%) than in Group WS (43 ± 6%) (P < 0.001).

CONCLUSIONS

Automatic retention pressure control of the DLT bronchial cuff improves the rate of TV reduction during right main bronchial traction in an artificial intubation model. Continuous retention cuff pressure may be useful in maintaining OLV during thoracic surgery.

Physiological effects of two driving pressure-based methods to set positive end-expiratory pressure during one lung ventilation

During one-lung ventilation (OLV), titrating the positive end-expiratory pressure (PEEP) to target a low driving pressure (∆P) could reduce postoperative pulmonary complications. However, it is unclear how to conduct PEEP titration: by stepwise increase starting from zero PEEP (PEEP_INCREMENTAL) or by stepwise decrease after a lung recruiting manoeuvre (PEEP_DECREMENTAL). In this randomized trial, we compared the physiological effects of these two PEEP titration strategies on respiratory mechanics, ventilation/perfusion mismatch and gas exchange. Patients undergoing video-assisted thoracoscopic surgery in OLV were randomly assigned to a PEEP_INCREMENTAL or PEEP_DECREMENTAL strategy to match the lowest ∆P. In the PEEP_INCREMENTAL group, PEEP was stepwise titrated from ZEEP up to 16 cm H₂O, whereas in the PEEP_DECREMENTAL group PEEP was decrementally titrated, starting from 16 cm H₂O, immediately after a lung recruiting manoeuvre. Respiratory mechanics, ventilation/perfusion mismatch and blood gas analyses were recorded at baseline, after PEEP titration and at the end of surgery. Sixty patients were included in the study. After PEEP titration, shunt decreased similarly in both groups, from 50 [39-55]% to 35 [28-42]% in the PEEP_INCREMENTAL and from 45 [37-58]% to 33 [25-45]% in the PEEP_DECREMENTAL group (both p < 0.001 vs baseline). The resulting ∆P, however, was lower in the PEEP_DECREMENTAL than in the PEEP_INCREMENTAL group (8 [7-11] vs 10 [9-11] cm H₂O; p = 0.03). In the PEEP_DECREMENTAL group the PaO₂/ FIO₂ ratio increased significantly after intervention (from 140 [99-176] to 186 [152-243], p < 0.001). Both the PEEP_INCREMENTAL and the PEEP_DECREMENTAL strategies were able to decrease intraoperative shunt, but only PEEP_DECREMENTAL improved oxygenation and lowered intraoperative ΔP.Clinical trial number NCT03635281; August 2018; "retrospectively registered".

Dexmedetomidine alleviates non-ventilation associated lung injury via modulating immunology phenotypes of macrophages

AIMS

We aimed to evaluate the effect of Dexmedetomidine (Dex) on immunology function of macrophages and inflammatory reactions in non-ventilated lung tissues from both humans and rats.

MAIN METHODS

Patients scheduled for lung lobectomy were randomly assigned to traditional anesthesia group or Dex anesthesia group, 15 subjects in each group. CD68, CD86 and CD206 were used to mark activate and polarized macrophages using immunofluorescence staining in human lung tissues. Sprague-Dawley rats were used to set lung injury model and randomly divided into Control group, one-lung ventilation group (CLI group) and CLI + Dex group. Lung tissues and bronchoalveolar lavage fluid (BALF) from non-ventilated lungs were collected. The acquired lung tissues were subjected to hematoxylin-eosin (H&E) staining and the inflammatory cells in BALF were calculated. Levels of cytokines and chemokines were detected by enzyme-linked immunosorbent assays (ELISA).

KEY FINDINGS

Results from humans showed that anesthesia with Dex decreased the number of both CD68 positive cells and CD86 positive cells and down-regulated level of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and monocyte chemotactic protein 1 (MCP-1) in human lung. Results from rats demonstrated that treatment with Dex reversed the increased inflammatory cells in lung and the increased levels of TNF-α, interleukin-1β (IL-β), MCP-1 and chemokine (C-X-C motif) ligand 1 (CXCL1) resulted from non-ventilation; Dex increased the anti-inflammatory cytokine interleukin-10 (IL-10) in BALF from non-ventilated lung.

SIGNIFICANCE

This study showed that Dex modulated the activation and immunological function of macrophages in non-ventilated lung and revealed a protective role in collapsed lung injury.

The fraction of nitrous oxide in oxygen for facilitating lung collapse during one-lung ventilation with double lumen tube

BACKGROUND

The ideal fraction of nitrous oxide (N₂O) in oxygen (O₂) for rapid lung collapse remains unclear. Accordingly, this prospective trial aimed to determine the 50% effective concentration (EC₅₀) and 95% effective concentration (EC₉₅) of N₂O in O₂ for rapid lung collapse.

METHODS

This study included 38 consecutive patients undergoing video-assisted thoracoscopic surgery (VATS). The lung collapse score (LCS) of each patient during one-lung ventilation was evaluated by the same surgeon. The first patient received 30% N₂O in O₂, and the subsequent N₂O fraction in O₂ was determined by the LCS of the previous patient using the Dixon up-and-down method. The testing interval was set at 10%, and the lowest concentration was 10% (10, 20, 30, 40%, or 50%). The EC₅₀ and EC₉₅ of N₂O in O₂ for rapid lung collapse were analyzed using a probit test.

RESULTS

According to the up-and-down method, the N₂O fraction in O₂ at which all patients exhibited successful lung collapse was 50%. The EC₅₀ and EC₉₅ of N₂O in O₂ for rapid lung collapse were 27.7% (95% confidence interval 19.9-35.7%) and 48.7% (95% confidence interval 39.0-96.3%), respectively.

CONCLUSIONS

In patients undergoing VATS, the EC₅₀ and EC₉₅ of N₂O in O₂ for rapid lung collapse were 27.7 and 48.7%, respectively.

TRIAL REGISTRATION

http://www.chictr.org/cn/ Identifier ChiCTR19 00021474 , registered on 22 February 2019.