One-lung Ventilation Research Articles

Effect of ventilation mode on postoperative pulmonary complications following lung resection surgery: a randomised controlled trial.

The effect of intra-operative mechanical ventilation modes on pulmonary outcomes after thoracic surgery with one-lung ventilation has not been well established. We evaluated the impact of three common ventilation modes on postoperative pulmonary complications in patients undergoing lung resection surgery. In this two-centre randomised controlled trial, 1224 adults scheduled for lung resection surgery with one-lung ventilation were randomised to one of three groups: volume-controlled ventilation; pressure-controlled ventilation; and pressure-control with volume guaranteed ventilation. Enhanced recovery after surgery pathways and lung-protective ventilation protocols were implemented in all groups. The primary outcome was a composite of postoperative pulmonary complications within the first seven postoperative days. The outcome occurred in 270 (22%), with 87 (21%) in the volume control group, 89 (22%) in the pressure control group and 94 (23%) in the pressure-control with volume guaranteed group (p = 0.831). The secondary outcomes also did not differ across study groups. In patients undergoing lung resection surgery with one-lung ventilation, the choice of ventilation mode did not influence the risk of developing postoperative pulmonary complications. This is the first randomised controlled trial examining the effect of three ventilation modes on pulmonary outcomes in patients undergoing lung resection surgery.

Effects of combined one-lung ventilation and intrathoracic carbon dioxide insufflation on intrathoracic working space when performing thoracoscopy in dogs.

To evaluate the effects of combining one-lung ventilation and carbon dioxide insufflation (OLV-CDI) on intrathoracic working space (determined by means of CT) during thoracoscopy in dogs and investigate conditions that could safely improve working space compared with OLV alone. 6 healthy Beagles. Dogs were anesthetized, and right- or left-sided (n = 3/side) OLV was instituted. On the blocked side, a laparoscopic trocar sleeve was placed in the ninth intercostal space for CDI. CT was performed under 3 conditions: with OLV alone, with OLV-CDI at an intrapleural pressure (IPP) of 3 mm Hg, and with OLV-CDI at an IPP of 5 mm Hg. Working space volume (WSV), ventilation space volume (VSV), and thoracic cavity volume (TCV) were determined from CT images. With OLV-CDI at an IPP of 3 or 5 mm Hg, WSV and TCV were significantly increased, compared with values obtained during OLV alone. With OLV-CDI at an IPP of 5 mm Hg, VSV and Spo2 were significantly decreased, compared with values obtained during OLV alone. Additionally, contralateral pneumothorax was observed in 4 dogs at an IPP of 5 mm Hg. Combining OLV and CDI could provide a larger working space than OLV alone, even with an IPP of 3 mm Hg, in dogs of limited size. However, an evaluation of the effects on oxygenation and cardiovascular variables is needed before clinical use.

Flurbiprofen used in one-lung ventilation improves intraoperative regional cerebral oxygen saturation and reduces the incidence of postoperative delirium.

BackgroundWe previously demonstrated that flurbiprofen increased arterial oxygen partial pressure and reduced intrapulmonary shunts. The present study aims to investigate whether flurbiprofen improves intraoperative regional cerebral oxygen saturation (rScO2) and reduces the incidence of postoperative delirium (POD) in elderly patients undergoing one-lung ventilation (OLV).MethodsOne hundred and twenty patients undergoing thoracoscopic lobectomy were randomly assigned to the flurbiprofen-treated group (n = 60) and the control-treated group (n = 60). Flurbiprofen was intravenously administered 20 minutes before skin incision. The rScO2 and partial pressure of arterial oxygen (PaO2) were recorded during the surgery, and POD was measured by the Confusion Assessment Method (CAM) within 5 days after surgery. The study was registered in the Chinese Clinical Trial Registry with the number ChiCTR1800020032.ResultsCompared with the control group, treatment with flurbiprofen significantly improved the mean value of intraoperative rScO2 as well as the PaO2 value (P < 0.05, both) and significantly reduced the baseline values of the rScO2 area under threshold (AUT) (P < 0.01) at 15, 30, and 60 min after OLV in the flurbiprofen-treated group. After surgery, the POD incidence in the flurbiprofen-treated group was significantly decreased compared with that in the control group (P < 0.05).ConclusionTreatment with flurbiprofen may improve rScO2 and reduce the incidence of POD in elderly patients undergoing thoracoscopic one-lung ventilation surgery for lung cancer.Clinical trial registrationhttp://www.chictr.org/cn/, identifier ChiCTR1800020032.

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

以电视辅助胸腔镜技术为代表的微创胸外科，已逐步取代传统胸外科技术成为肺部结节包括早期肺癌等在内治疗的首要选择方式。随着双腔支气管导管在临床的应用，实现患侧肺隔离技术，不仅为胸外科微创手术的普及提供了坚实的麻醉基础，也为手术快速而平稳的实施提供了保障。然而，相较于单腔管而言，双腔支气管导管的管径更粗，管身较硬且难以塑形，给麻醉插管带来了不便；此外，由于双腔支气管导管的左、右支气管结构不同，麻醉插管过程中错位的发生率也很高。随着可视双腔支气管导管（video double-lumen tube, VDLT）在临床上逐渐使用，近年来成为胸科手术中的关注热点。本文就VDLT在胸外科手术中的应用和研究进展做一综述。

Goal-directed therapy based on rScO2 monitoring in elderly patients with one-lung ventilation: a randomized trial on perioperative inflammation and postoperative delirium

BackgroundThe incidence of postoperative delirium (POD) is high in elderly patients with one-lung ventilation, which is mostly related to the impairment of cerebral oxygen supply/demand balance during operation. (Surgical) stress can cause changes to normal physiological function and increase oxygen supply to the brain. When cerebral oxygen supply/demand is unbalanced, other organs may have already suffered from hypoperfusion or even hypoxic damages leading to increased release of inflammatory factors. Regional saturation of cerebral oxygenation (rScO2) monitoring can noninvasively monitor the variation of regional cerebral oxygen supply/demand balance in real time, and it has a good correlation with the occurrence of POD. S-100β is one of the markers commonly used to predict and diagnose POD, and lactate is one of the important indicators for the quality of tissue perfusion. The study explores whether the goal-directed therapy based on rScO2 monitoring can reduce perioperative inflammatory factor levels and POD incidence in elderly patients with one-lung ventilation and improve tissue perfusion.MethodsThe study is registered on Chinese Clinical Trial Registry (ChiCTR2100054888). A total of 159 patients scheduled for thoracoscopic lobectomy under general anesthesia were divided into the control group (n = 81) and the goal-directed therapy group (GDT group, n = 78). On the basis of the conventional management in the control group, the GDT group applied goal-directed rScO2 monitoring to maintain rScO2 at ±20% baseline level during one-lung ventilation. The levels of interleukin-1β, interleukin-6, tumor necrosis factor-α, and lactate; the intensity of postoperative pain; and the incidence of POD before anesthesia (T1), at the end of operation (T2), on day 1 after operation (T3), on day 3 after operation (T4), and on day 7 after operation or before discharge (T5) were compared respectively between the two groups.ResultsThe incidence of POD at T3 and the awakening time in the GDT group were lower than those in the control group (P < 0.05). During T2 to T4, the levels of inflammatory factors and lactate concentration in the control group were higher than those in the GDT group (P < 0.05). During T3 to T4, the levels of C-reactive protein and lactate in the control group were higher than those in the GDT group (P < 0.05). During T2 to T3, the levels of S-100β in the control group were higher than those in the GDT group (P < 0.05). The levels of inflammatory factors and lactate concentration in both groups during T2 to T4 were higher than those at T1 and T5 (P < 0.05), and there was no statistical difference at T1 versus T5 (P > 0.05). There was no significant difference in postoperative pain intensity, the incidence of agitation during awakening, and postoperative hospital stays between the two groups.ConclusionGoal-directed therapy based on rScO2 monitoring can reduce perioperative inflammatory factor levels, postoperative delirium incidence, and postoperative awakening time and improve tissue perfusion in elderly patients with one-lung ventilation.Trial registrationThe Chinese Clinical Trial Registry ChiCTR2100054888. Registered on 28 December 2021

Development and Validation of a Nomogram for Predicting Postoperative Pulmonary Infection in Patients Undergoing Lung Surgery

To develop and validate a nomogram for predicting postoperative pulmonary infection (PPI) in patients undergoing lung surgery. Single-center retrospective cohort analysis. A university-affiliated cancer hospital PARTICIPANTS: A total of 1,501 adult patients who underwent lung surgery from January 2018 to December 2020. Observation for PPI within 7 days after lung surgery. A complete set of demographics, preoperative variables, and postoperative follow-up data was recorded. The primary outcome was PPI; a total of 125 (8.3%) out of 1,501 patients developed PPI. The variables with p < 0.1 in univariate logistic regression were included in the multivariate regression, and multivariate logistic regression analysis showed that surgical procedure, surgical duration, the inspired fraction of oxygen in one-lung ventilation, and postoperative pain were independent risk factors for PPI. A nomogram based on these factors was constructed in the development cohort (area under the curve: 0.794, 95% CI 0.744-0.845) and validated in the validation cohort (area under the curve: 0.849, 95% CI 0.786-0.912). The calibration slope was 1 in the development and validation cohorts. Decision curve analysis indicated that when the threshold probability was within a range of 0.02-to-0.58 and 0.02-to-0.42 for the development and validation cohorts, respectively, the nomogram model could provide a clinical net benefit. The authors developed and validated a nomogram for predicting PPI in patients undergoing lung surgery. The prediction model can predict the development of PPI and identify high-risk groups.

Anesthetic Management of Patient with Mediastinal Tumor Posted for Thoracotomy and Tumor Excision

Introduction: Mediastinal tumor are uncommon entity they present a major anesthetic challenges due to major airway and vascular compression. Case Report: A 60yr, old diagnosed with posterior mediastinum tumour at C7 level. Airway assessment revealed mallampatti class IV. Blood investigations were within normal limit. Pulmonary function test revealed mild obstructive disease. CT shows lesion in posterior mediastinum extending to right IJV with complete thrombosis displacing trachea and thyroid. Triple lumen CVP line was secured. Difficult intubation trolley with tracheostomy set was kept ready. Routine monitoring, left radial artery cannulation done. Patient was Preoxygenated, Premedicated and Induced. 37F Left Double lumen tube was inserted and tube position confirmed with paediatric fiberoptic bronchoscope. Patient was hemodynamically stable in the intraoperative period. Patient was reversed and extubated uneventfully. Conclusion: Mediastinal tumor resection surgery is a very complicated and requires a team effect anesthesiologists, surgeon and intensivist. A thorough pre-operative assessment of the patient should be done before the conduct of anesthesia to avoid the complications due to posterior mediastinal mass. Keywords: Thoracotomy, One-Lung Ventilation, Mediastinal Tumor. Key Messages: Anesthetic management of patient with mediastinal tumor posted for thoracotomy and tumor excision requires a double lumen ET tube for lung isolation and decrease in lung atelectasis. In this case a 60 year old male presented with mild symptoms and we highlight the usage of one lung ventilation in patient with posterior mediastinal tumor.

Trachway® flexible stylet facilitates the correct placement of double-lumen endobronchial tube: a prospective, randomized study

BackgroundThe mainstream facilitation of one-lung ventilation is using double-lumen endobronchial tubes. However, it is more difficult to be positioned properly and more likely to cause airway injuries. How to place double-lumen endobronchial tubes rapidly and correctly is important for thoracic anesthesiologists.MethodsOne hundred eight patients with an American Society of Anesthesiologists physical status of I to III were 20 years of age or over, and required one-lung ventilation for thoracic surgery. They were randomly assigned to the conventional technique group (n = 36), the flexible fiberoptic bronchoscopy group (n = 36), or the Trachway® flexible stylet group (n = 36). The primary endpoint was the time needed for intubation. T1, the time from the tip of the blade passing between the patient’s lips to identification of the vocal cords; and T2, the time from identification of the vocal cords to the bronchial lumen was in the correct position.ResultsT1 had no significant difference between groups, but T2 was significantly shorter in the Trachway® flexible stylet group (p < 0.0001) and longer in the conventional technique group (p < 0.0001).ConclusionsUsing Trachway® flexible stylet for correct placement of double-lumen endobronchial tubes not only significantly shortened the intubation time, but also reduced incidence of carinal injuries. It is an alternative, and a choice with good safety.Trial registrationClinicalTrials.gov Identifier: NCT02364622, 18/02/2015, Retrospectively registered.

The Year in Thoracic Anesthesia: Selected Highlights From 2021

THIS SPECIAL ARTICLE is the fifth in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors would like to thank the editor-in-chief, Dr. Kaplan; the associate editor-in-chief, Dr. Augoustides; and the editorial board for the opportunity to expand this series, the research highlights of the year that specifically pertain to the specialty of thoracic anesthesia. The highlights of this year include new developments in the preoperative assessment and prehabilitation of thoracic surgery patients, updates on the use of devices for one-lung ventilation (OLV) in adults and children, updates on the anesthetic management of these patients, including protective ventilation, regional anesthesia, and outcomes when enhanced recovery after thoracic surgery protocols are followed, as well as the use of expanding indications for extracorporeal membrane oxygenation (ECMO) and nonintubated video-assisted thoracic surgery (NIVATS).

Spontaneous hyperinflation of a giant bulla of the non-ventilated lung during laparoscopic cholecystectomy under one-lung ventilation: a case report

BackgroundAnesthetic management of non-thoracic surgery in patients with giant bullae is challenging. We present a case of laparoscopic cholecystectomy in a patient with a giant bulla managed with one-lung ventilation (OLV).Case presentationA 75-year-old man with a giant bulla occupying the lower half of the right hemithorax underwent laparoscopic cholecystectomy. We managed anesthesia with OLV to avoid positive pressure ventilation of the giant bulla. Surgery was completed uneventfully; however, postoperative chest radiography indicated a large lucency occupying the entire right hemithorax. Although we suspected a pneumothorax due to a ruptured bulla, chest computed tomography (CT) led to a diagnosis of giant bulla hyperinflation. The giant bulla deflated gradually to its preoperative size within three postoperative days.ConclusionsManaging laparoscopic cholecystectomy in a patient with a giant bulla with OLV resulted in spontaneous hyperinflation of the giant bulla. Chest CT ruled out a pneumothorax.

Adverse outcomes of artificial pneumothorax under right bronchial occlusion for patients with thoracoscopic-assisted oesophagectomy in the prone position versus the semiprone position.

BackgroundThere are few studies on the impact of body position on variations in circulation and breathing, and it has not been confirmed whether body position changes can reduce the pulmonary complications of thoracoscopic-assisted oesophagectomy.MethodsA single-center retrospective study included patients undergoing thoracoscopic-assisted oesophagectomy in the prone position or semiprone position between 1 July 2020, and 30 June 2021, at the Shanghai Chest Hospital. There were 103 patients with thoracoscopic-assisted oesophagectomy in the final analysis, including 43 patients undergoing thoracoscopic-assisted oesophagectomy in the prone position. Postoperative pulmonary complication (PPC) incidence was the primary endpoint. The incidence of cardiovascular and other complications was the secondary endpoint. Chest tube duration, patient-controlled anaesthesia (PCA) pressing frequency within 24 h, ICU stay, and the postoperative hospital length of stay (LOS) were also collected.ResultsCompared with the semiprone position, the prone position decreased the incidence of atelectasis (12% vs. 30%, P = 0.032). Nevertheless, there were no considerable differences in the rates of cardiovascular and other complications, ICU stay, or LOS (P >0.05). Multivariable logistic regression analysis showed that the prone position (OR = 0.196, P = 0.011), no smoking (OR = 0.103, P <0.001), preoperative DLCO% ≥90% (OR = 0.230, P = 0.003), and an operative time <180 min (OR = 0.268, P = 0.006) were associated with less atelectasis.ConclusionsOur study shows that artificial pneumothorax under right bronchial occlusion one-lung ventilation for patients with thoracoscopic-assisted oesophagectomy in the prone position can decrease postoperative atelectasis compared with the semiprone position.

A Review of Anesthesia for Lung Transplantation.

Lung transplantation is the only treatment option for patients with end-stage lung disease. Although more than 4,000 lung transplants are performed every year worldwide, the standardized protocols contain no guidelines for monitoring during lung transplantation. Specific anesthetic concerns are associated with lung transplantation, especially during critical periods, including anesthesia induction, the initiation of positive pressure ventilation, the establishment and maintenance of one-lung ventilation, pulmonary artery clamping, pulmonary artery unclamping, and reperfusion of the transplanted lung. Anesthetic management according to the special risks associated with a patient’s existing lung disease and surgical stage is the most important factor. Successful anesthesia in lung transplantation can improve hemodynamic stability, oxygenation, ventilation, and outcomes. Therefore, anesthesiologists must have expertise in transesophageal echocardiography, extracorporeal life support, and cardiopulmonary anesthesia and understand the pathophysiology of end-stage lung disease and the drugs administered. In addition, communication among anesthesiologists, surgeons, and perfusionists during surgery is important to achieve optimal patient results.

Anesthetic (r)evolution from the conventional concept to the minimally invasive techniques in thoracic surgery-narrative review.

Background and ObjectiveThanks to the growing experience with the non-intubated anesthetic and surgical techniques, most pulmonary resections can now be performed by using minimally invasive techniques. The conventional method, i.e., surgery on the intubated, ventilated patient under general anesthesia with one-lung ventilation (OLV) was considered necessary for the major thoracoscopic lung resections for all patients. An adequate analgesic approach (regional or epidural anesthesia) allows video-assisted thoracoscopy (VATS) to be performed in anesthetized patients and thus the potential adverse effects related to general anesthesia and mechanical OLV can be minimized.MethodsMultiple medical literature databases (PubMed, Google Scholar, Scopus) were searched, using the terms [(non-intubated) OR (nonintubated) OR (tubeless) OR (awake)] AND [(thoracoscopic surgery)] from 2004 to December 2021. Thirty hundred and six scientific papers were collected. The editorials, commentaries, letters, and papers were excluded, that focus on other than the non-intubated (aka awake or tubeless) VATS technique, as well as the full text scientific papers available in languages other than English.Key Content and FindingsAfter reviewing the literature, we identified “schools” with different techniques but with very similar results. Most of the differences were in the anesthetic technique, oxygenation and analgesia, however, the immunological results, and the qualitative parameters (inpatient hospital care days, complication rate, mortality) of the perioperative period showed great similarity, in addition, all three schools identified the same risk factors (hypoxia, hypercapnia, airway safety). The combination of spontaneous ventilation with double lumen tube intubation, called VATS-spontaneous ventilation with intubation (SVI) method seems to be suitable for reducing these risk factors, which may serve as an alternative for patients not suitable for the non-intubated technique in the near future.ConclusionsBased on the results, non-intubated thoracic surgery appears to be an increasingly widespread, safe procedure, that will be available to a wider range of patients as experience expands and by the implication of the constantly evolving new processes.

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.

A human model of bilateral pulmonary vein sampling to assess the effects of one-lung ventilation on neutrophil function.

BackgroundNeutrophil activation drives lung complications after cardiopulmonary bypass (CPB). Evidence suggests the healthy, ventilated lung may beneficially re-condition pro-inflammatory neutrophils. However, evidence in humans is lacking, due to a paucity of good models. CPB with simultaneous central venous and bilateral pulmonary vein sampling provides an opportunity to model effects of one-lung ventilation. The study’s primary objectives were to establish a model of intra-operative, bilateral pulmonary vein sampling and to determine whether neutrophil function differed after passing through inflated or deflated lungs.MethodsSeventeen patients having “on pump” coronary artery bypass grafting (CABG) with one-lung ventilation (in two cohorts with tidal volume 2ml kg-1 and FiO2 0.21, or tidal volume 4 ml kg-1 and FiO2 0.5 respectively) were recruited. Cohort 1 consisted of 9 patients (7 male, median age 62.0 years) and Cohort 2 consisted of 8 male patients (median age 65.5 years). Recruitment was via prospective screening of scheduled elective and non-elective CABG procedures with cardiopulmonary bypass. Each patient had five blood samples taken—central venous blood pre-operatively; central venous blood pre-CPB; central venous blood post-CPB; pulmonary venous blood draining the ventilated lung post-CPB; and pulmonary venous blood draining the deflated lung post-CPB. Neutrophil phagocytosis and priming status were quantified. Plasma cytokines were measured.ResultsPhagocytosis and priming were not significantly different in neutrophils returning from the ventilated lung as compared to the non-ventilated lung. Plasma IL-6, IL-8 and IL-10 were significantly elevated by CPB.ConclusionsThe intra-operative, bilateral pulmonary vein sampling model provides unique opportunities to assess biological effects of interventions to one lung, with the other lung acting as an internal control. Single-lung ventilation during CPB had no significant effects on neutrophil function.

One-lung ventilation and 3D image analysis in a case of tracheal bronchus with steeply angled branching of left main bronchus: a case report

BackgroundEstablishing one-lung ventilation (OLV) in patients with tracheal bronchus (TB) may be challenging due to its unusual bronchial anatomy. We present a case of difficult OLV in a patient with right TB and steeply angled bifurcation of the left main bronchus.Case presentationA 79-year-old woman was scheduled to undergo video-assisted thoracic surgery left upper lobectomy. We planned right OLV with a bronchial blocker; however, it was difficult to place the blocker in the left main bronchus due to a steep bifurcation angle. Therefore, we changed the entry angle of the lumen tip by advancing the tracheal tube to just above the tracheal bifurcation, allowing successful placement of the bronchial blocker into the bronchus.ConclusionFor airway management in patients with TB, especially for OLV, it is essential to understand the anatomy of the trachea, bronchus, and TB and to select the appropriate device for each case.

Low tidal volume ventilation alleviates ventilator-induced lung injury by regulating the NLRP3 inflammasome

Purpose Low tidal volume ventilation (LTVV) is a well-known ventilation mode which can improve ventilator-induced lung injury (VILI). However, the mechanism of LTVV ameliorating VILI has not yet been elucidated. In this study, we aimed to reveal LTVV protected against VILI by inhibiting the activation of the NLRP3 inflammasome in bronchoalveolar lavage fluid (BALF) from humans and lungs from mice. Materials and Methods Twenty-eight patients scheduled for video-assisted thoracoscopic esophagectomy were randomized to receive high-tidal-volume ventilation [Vt = 10 mL/kg without positive end-expiratory pressure (PEEP)] or LTVV (Vt = 5 mL/kg along with 5 cm of H2O PEEP) during one-lung ventilation. BALF was collected before and at the end of surgery. Male C57BL/6 mice received high-tidal-volume ventilation, LTVV or MCC950 (an inhibitor of NLRP3). The activation of the formation of NLRP3 inflammasome in BALF from patients and in lungs from mice were analyzed. Results LTTV decreased the peak airway pressure (P peak), plateau airway pressure (P plat) and driving pressure (ΔP) during one-lung ventilation. Additionally, LTVV not only inhibited pulmonary infiltration and inflammation caused by mechanical ventilation, but also suppressed the NLRP3 inflammasome activation in BALF from humans. In mice, ventilator-induced inflammatory response and pulmonary edema were suppressed by LTVV with an efficacy comparable to that of MCC950 treatment. Furthermore, LTVV, similar to MCC950, clearly decreased ventilator-induced NLRP3 inflammasome activation. Conclusion Our study showed that LTVV played a protective role in ventilator-induced lung injury by suppressing the activation of the NLRP3 inflammasome. Trial registration This study was registered in The Chinese Clinical Trial Registry, ChiCTR1900026190 on 25 September 2019.

Effects of Positive End-Expiratory Pressure on Intraocular Pressure during One-Lung Ventilation in the Lateral Decubitus Position-A Prospective Randomized Trial.

Background and Objectives: The effect of positive end-expiratory pressure (PEEP) on intraocular pressure (IOP) is debatable. There have been no studies investigating the effects of PEEP on IOP during one-lung ventilation (OLV). We aimed to investigate the effects of PEEP on IOP in patients undergoing OLV for video-assisted thoracoscopic surgery (VATs). Materials and Methods: Fifty-two patients undergoing VATs were divided into a zero-PEEP (ZEEP) and a 6 cmH2O of PEEP (PEEP) groups. IOP, ocular perfusion pressure (OPP), and respiratory and hemodynamic parameters were measured before induction (T1), immediately following endotracheal intubation (T2), 30 min (T3) and 60 min (T4) after a position change to the lateral decubitus position (LDP) and OLV, and 10 min following two-lung ventilation near the end of the surgery (T5). Results: There was no significant difference in IOP and OPP between the two groups. The IOP of the dependent eye was significantly higher than that of the non-dependent eye during LDP in both groups. Peak inspiratory pressure was significantly higher in the PEEP group than in the ZEEP group at T3–T5. Dynamic compliance was significantly higher in the PEEP group than in the ZEEP group at T2–T5. The ratio of arterial oxygen partial pressure to fractional inspired oxygen was significantly higher in the PEEP group than in the ZEEP group at T4. Conclusions: Applying 6 cmH2O of PEEP did not increase IOP but enhanced dynamic compliance and oxygenation during OLV. These results suggest that 6 cmH2O of PEEP can be safely applied during OLV in LDP.

El efecto de diferentes técnicas de anestesia sobre la oxigenación cerebral en cirugía torácica

One-lung ventilation may cause negative changes in the oxygenation of cerebral tissue which results in post-operative cognitive dysfunction. We compared the potential effects of total intravenous anesthesia and inhalation general anesthesia techniques on cerebral tissue oxygenation. In this prospective double-blind trial, patients whose standard anesthesia induction was done were randomly divided into two groups as group total intravenous anesthesia using propofol (Group T, n = 30) and group inhalation general anesthesia using sevoflurane (Group I, n = 30) based on anesthesia maintenance. The intraoperative cerebral oxygen saturation and pre-post-operative mini-mental status test scores of the patients were monitored and recorded. Baseline characteristics were similar between the two groups. The decrease of cerebral oxygen saturation more than 20% in total intravenous anesthesia group was significantly higher than inhalation group (p < 0.05). In both groups, the mini-mental status test values at the post-operative 3rd h were significantly lower than the pre-operative and post-operative 24th h values (p < 0.05). Inhalation general anesthesia provided better cerebral tissue oxygenation in thoracic surgery with one-lung ventilation compared to total intravenous anesthesia. However, there was no significant correlation between the presence of desaturation and post-operative cognitive dysfunction.

One lung ventilation techniques in infants and small children

In children below six years old, OLV is challenging due to technical issues such as unavailable double-lumen tube(DLT) for this age group, unavailable visual-assisted airway technology in pediatric sizes and the unfamiliarity to pediatric airway management tecniques. We aim to report our approaches for three cases of OLV in infants and pediatrics patients undergoing surgery. Three cases of pediatric patients with lung masses aged two-month-old, 11-month-old and three years old are reported in this case series involving the use of a single lumen ETT and Fogarty embolectomy catheters as a surrogate for bronchial blocker with and without the use of a video-assisted device. The sizes of the patient's airway and the equipment available significantly impact the choice of technique in pediatrics. Availability of a video-assisted airway device improves the working field's visualization provides a suctioning method and evaluation of the technique. Combining anatomical knowledge, sizing and modification of available equipment and simulation training is critical in providing one-lung ventilation for pediatric patients.