Acute lung injury in thoracic surgery. Curr Opin Anaesthesiol. 2013;26:40-46. [PMID: 23235524 DOI: 10.1097/aco.0b013e32835c4ea2]

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.

One-Lung Ventilation and Postoperative Pulmonary Complications After Major Lung Resection Surgery. A Multicenter Randomized Controlled Trial

OBJECTIVES

The effect of one-lung ventilation (OLV) strategy based on low tidal volume (TV), application of positive end-expiratory pressure (PEEP), and alveolar recruitment maneuvers (ARM) to reduce postoperative acute respiratory distress syndrome (ARDS) and pulmonary complications (PPCs) compared with higher TV without PEEP and ARM strategy in adult patients undergoing lobectomy or pneumonectomy has not been well established.

DESIGN

Multicenter, randomized, single-blind, controlled trial.

SETTING

Sixteen Italian hospitals.

PARTICIPANTS

A total of 880 patients undergoing elective major lung resection.

INTERVENTIONS

Patients were randomized to receive lower tidal volume (LTV group: 4 mL/kg predicted body weight, PEEP of 5 cmH2O, and ARMs) or higher tidal volume (HTL group: 6 mL/kg predicted body weight, no PEEP, and no ARMs). After OLV, until extubation, both groups were ventilated using a tidal volume of 8 mL/kg and a PEEP value of 5 cmH2O. The primary outcome was the incidence of in-hospital ARDS. Secondary outcomes were the in-hospital rate of PPCs, major cardiovascular events, unplanned intensive care unit (ICU) admission, in-hospital mortality, ICU length of stay, and in-hospital length of stay.

MEASUREMENTS AND MAIN RESULTS

ARDS occurred in 3 of 438 patients (0.7%, 95% CI 0.1-2.0) and in 1 of 442 patients (0.2%, 95% CI 0-1.4) in the LTV and HTV group, respectively (Risk ratio: 3.03 95% CI 0.32-29, p = 0.372). Pulmonary complications occurred in 125 of 438 patients (28.5%, 95% CI 24.5-32.9) and in 136 of 442 patients (30.8%, 95% CI 26.6-35.2) in the LTV and HTV group, respectively (risk ratio: 0.93, 95% CI 0.76-1.14, p = 0.507). The incidence of major complications, in-hospital mortality, and unplanned ICU admission, ICU and in-hospital length of stay were comparable in both groups.

CONCLUSIONS

In conclusion, among adult patients undergoing elective lung resection, an OLV with lower tidal volume, PEEP 5 cmH2O, and ARMs and a higher tidal volume strategy resulted in low ARDS incidence and comparable postoperative complications, in-hospital length of stay, and mortality.

Postoperative Hypoxemia After Dual-Controlled vs Volume-Controlled Ventilation in Lung Surgery

BACKGROUND

One-lung ventilation for thoracic surgery represents a challenge due to the risk for hypoxemia and barotrauma. Dual-controlled ventilation (ie, pressure-regulated volume control [PRVC]) may confer improved lung mechanics compared with conventional ventilation (volume-controlled ventilation [VCV]). Our objective was to determine the association between ventilatory mode and pulmonary outcomes after lung resection surgery.

METHODS

A historical cohort (2016-2021) of patients undergoing lung resection surgery was used to identify cases performed with PRVC ventilation (intervention) vs VCV (conventional). Both groups were matched in a 1:1 fashion using propensity scoring based on preoperative oxygen saturation, chronic obstructive pulmonary disease, intraoperative ventilator settings, and surgical approach. Our primary outcome was postoperative hypoxemia (oxygen saturation <92% requiring supplemental oxygen longer than 2 hours). Secondary outcomes included respiratory failure, pneumonia, atelectasis, acute respiratory distress syndrome, pleural effusion, and reintubation. Associations were reported using adjusted odds ratios (aOR).

RESULTS

Of 2107 eligible patients (PRVC = 1587 vs VCV = 520), a total of 774 matched pairs were analyzed (PRVC = 387 vs VCV = 387). The overall incidence of postoperative hypoxemia was 35.5% (95% CI 32.2%-39.0%). Hypoxemia was less likely among patients managed with low tidal volumes (≤6 mL/kg per ideal body weight, aOR 0.73, 95% CI 0.57-0.92, P = .008). No significant association was observed between ventilator mode and postoperative hypoxemia (33.3% in PRVC vs 37.7% in VCV; aOR 0.93, 95% CI 0.71-1.23, P = .627) or secondary pulmonary complications (3.9% in PRVC vs 3.4% in VCV; aOR 0.96, 95% CI 0.47-1.97, P = .909).

CONCLUSIONS

Dual-controlled ventilation was not associated with improved pulmonary outcomes compared with conventional ventilation in lung resection surgery.

Temporal and Spatial Patterns of Inflammation and Tissue Injury in Patients with Postoperative Respiratory Failure after Lung Resection Surgery: A Nested Case-Control Study

Thoracic surgeries involving resection of lung tissue pose a risk of severe postoperative pulmonary complications, including acute respiratory distress syndrome (ARDS) and respiratory failure. Lung resections require one-lung ventilation (OLV) and, thus, are at higher risk of ventilator-induced lung injury (VILI) attributable to barotrauma and volutrauma in the one ventilated lung, as well as hypoxemia and reperfusion injury on the operated lung. Further, we also aimed to assess the differences in localized and systemic markers of tissue injury/inflammation in those who developed respiratory failure after lung surgery versus matched controls who did not develop respiratory failure. We aimed to assess the different inflammatory/injury marker patterns induced in the operated and ventilated lung and how this compared to the systemic circulating inflammatory/injury marker pattern. A case-control study nested within a prospective cohort study was performed. Patients with postoperative respiratory failure after lung surgery (n = 5) were matched with control patients (n = 6) who did not develop postoperative respiratory failure. Biospecimens (arterial plasma, bronchoalveolar lavage separately from ventilated and operated lungs) were obtained from patients undergoing lung surgery at two timepoints: (1) just prior to initiation of OLV and (2) after lung resection was completed and OLV stopped. Multiplex electrochemiluminescent immunoassays were performed for these biospecimen. We quantified 50 protein biomarkers of inflammation and tissue injury and identified significant differences between those who did and did not develop postoperative respiratory failure. The three biospecimen types also display unique biomarker patterns.

Impact of interstitial lung abnormalities on postoperative pulmonary complications and survival of lung cancer

BACKGROUND

Interstitial lung abnormalities (ILAs) are associated with the risk of lung cancer and its mortality. However, the impact of ILA on treatment-related complications and survival in patients who underwent curative surgery is still unknown.

RESEARCH QUESTION

This study aimed to evaluate the significance of the presence of computed tomography-diagnosed ILA and histopathologically matched interstitial abnormalities on postoperative pulmonary complications (PPCs) and the long-term survival of patients who underwent surgical treatment for lung cancer.

STUDY DESIGN AND METHODS

A matched case-control study was designed to compare PPCs and mortality among 50 patients with ILA, 50 patients with idiopathic pulmonary fibrosis (IPF) and 200 controls. Cases and controls were matched by sex, age, smoking history, tumour location, the extent of surgery, tumour histology and pathological TNM stage.

RESULTS

Compared with the control group, the OR of the prevalence of PPCs increased to 9.56 (95% CI 2.85 to 32.1, p<0.001) in the ILA group and 56.50 (95% CI 17.92 to 178.1, p<0.001) in the IPF group. The 5-year overall survival (OS) rates of the control, ILA and IPF groups were 76% (95% CI 71% to 83%), 52% (95% CI 37% to 74%) and 32% (95% CI 19% to 53%), respectively (log-rank p<0.001). Patients with ILA had better 5-year OS than those with IPF (log-rank p=0.046) but had worse 5-year OS than those in the control group (log-rank p=0.002).

CONCLUSIONS

The presence of radiological and pathological features of ILA in patients with lung cancer undergoing curative surgery was associated with frequent complications and decreased survival.

Association between driving pressure and postoperative pulmonary complications in patients undergoing lung resection surgery: A randomised clinical trial

BACKGROUND

It is uncertain whether an association exists for decreases in driving pressure and the occurrence of postoperative pulmonary complications (PPCs) in patients undergoing selective lung resection surgery. Thus, we designed this study to determine whether the positive end-expiratory pressure (PEEP) titration to the lowest driving pressure compared with conventional low PEEP level during one-lung ventilation (OLV) in patients undergoing selective lung resection surgery decreases PPCs.

METHODS

This single-centre, randomised trial approved by the Ethical Committee of the Sun Yat-Sen University Cancer Center involved patients who signed written consent. Patients were randomised to the PEEP titration to the lowest driving pressure group (n = 104), or to the conventional low level of PEEP group (n = 103), consisting a PEEP level of 4 cm H₂O during OLV. All patients received volume-controlled ventilation with a tidal volume of 6 mL/kg of predicted body weight. The primary outcome was defined as positive if 4 or more of eight Melbourne Group Scale (MGS) variables developed within the first 3 days after surgery. The incidence of major PPCs occurring during postoperative 7 days was also recorded.

RESULTS

Among 222 patients who were randomised, 207 (93%) completed the trial (109 men [53%]; mean age, 56.9 years). The primary outcome occurred in 4 of 104 patients (4%) in the PEEP titration to the lowest driving pressure group compared with 13 of 103 patients (13%) in the conventional low level of PEEP group (risk ratio, 0.32 [95% CI, 0.10-0.90]; P = 0.021).

CONCLUSIONS

Among patients undergoing selective lung surgery, intraoperative OLV with PEEP titration to the lowest driving pressure compared with conventional low PEEP level (4 cm H₂O) significantly reduced PPCs within the first 3 postoperative days, however, did not significantly reduce PPCs within the first 7 postoperative days.

Awake uniportal VATS sublobar lung resections in high-comorbidity patients: Single-center early post-operative outcomes

Introduction

Awake minimally invasive Uniportal Video Assisted Thoracic Surgery (U-VATS) represents the last challenge in thoracic surgery that could change the future scenario for high comorbidity patients with early-stage non-small cell lung cancer (NSCLC). We report a single center preliminary experience of awake thoracoscopic uni-portal anatomic and non-anatomic sub-lobar resections in this setting.

Methods

We retrospectively analyzed data collected on a prospective database of patients undergoing U-VATS awake sub-lobar lung resections for NSCLC between September 2021 and September 2022. Inclusion criteria were clinical stage I disease; contraindication to standard lobectomy due to high respiratory function impairment; general anesthesia considered at high risk based on the American Society of Anesthesiologist score and on the Charlson Comorbidity Index. All patients underwent a standardized awake non-intubated anesthesia protocol approved by our institutional board.

Results

They were n = 10 patients: n = 8 wedge resections; n = 2 segmentectomies. We had n = 1 (10%) conversion to standard general anesthesia and n = 1 laryngeal mask support but maintaining spontaneous breathing. N = 5 patients (50%) needed an Intensive Care Unit recovery (mean time = 17.20 h). Mean chest tube duration and Hospital stay were 2.0 and 3.5 days respectively. We did not register 30- days postoperative mortality.

Conclusion

Awake thoracic surgery is a feasible technique, and it could be performed also in high comorbidities' patients without a high rate of complications and allows to operate patients that so far were considered borderline for surgery.

Diagnostic value and safety of medical thoracoscopy under local anesthesia for unexplained diffuse interstitial lung disease: A retrospective study

Objective

We aimed to explore the safety and diagnostic value of medical thoracoscopic lung biopsy in patients with unexplained diffuse interstitial lung disease (ILD) in a single center pilot study.

Method

We retrospectively analyzed clinical and pathological diagnostic data from 52 patients with diffuse ILD undergoing medical thoracoscopic lung biopsy.

Results

Forty-four cases of diffuse ILD were confirmed pathologically, giving a diagnostic rate of 84.6%. Among these 44 patients, 11 patients were diagnosed with cancer, including eight patients with lung adenocarcinoma, three patients with metastases; two from a gastrointestinal malignancy, and one from a granulosa cell tumor of the ovary. There were 17 cases of idiopathic interstitial pneumonia, including nine cases of usual interstitial pneumonia (UIP), four cases of non-specific interstitial pneumonia (NSIP), three cases of cryptogenic organizing pneumonia (COP), and one case of acute interstitial pneumonia (AIP). There were 12 cases of rare interstitial pneumonias, which included six cases of pulmonary alveolar proteinosis, one case each of pulmonary Langerhans cell histiocytosis (LCH) and pulmonary lymphangiomyomatosis, two cases of nodular sarcoidosis, and two cases of chronic eosinophilic pneumonia. We recorded various complications, including bleeding, infection, and pneumothorax. A total of 28 patients (53.8%) experienced at least one of the above complications, but there were no deaths associated with biopsy.

Conclusions

Medical thoracoscopic lung biopsy appears a safe and effective method for diagnosing diffuse ILD of unknown cause but further prospective studies, with larger numbers, including comparison with other established techniques are required.

Non-Intubated Thoracic Surgery: Standpoints and Perspectives

Non-intubated video-assisted thoracic surgery (NI-VATS) combines the advantages of a non-intubated surgery with the benefits of a minimally invasive approach. First, NI-VATS is performed in the case of fragile patients when general anesthesia and/or orotracheal intubation can be foreseen as inconvenient. However, NI-VATS indications have been increasingly extended to different patient conditions, considering the increasingly assessed safety and feasibility of the procedure. Currently, the NI-VATS approach is used worldwide for different thoracic surgery procedures, including the management of malignant pleural effusion, surgical treatment of empyema, anatomical and non-anatomical lung resection, and other indications. In fact, this approach has shown to be less impactful than VATS under general anesthesia, allowing for shortened hospitalization and faster recovery after surgery. Besides, NI-VATS is associated with fewer pulmonary complications, less respiratory distress, and a mild systemic inflammatory reaction. For these reasons, this approach should be considered not only in patients with poor cardiac or respiratory function (general functional reserve), but also in other eligible conditions.

We explored the anesthetic and surgical aspects of such an approach, including the management of analgesia, cough reflex, depth of sedation, and intraoperative technical issues to put this approach in perspective.

Effects of Non-intubated Video-Assisted Thoracic Surgery on Patients With Pulmonary Dysfunction

Background: Non-intubated video-assisted thoracic surgery (NIVATS) can be safely performed in lung volume reduction surgery for patients with severe pulmonary dysfunction. However, there is still no cohort observation on the effects of NIVATS on patients with pulmonary dysfunction undergoing different types of thoracic procedures. This retrospective study aimed to observe the effects of NIVATS for this kind of patients.

Methods: Three hundred and twenty-eight patients with moderate to severe obstructive pulmonary dysfunction, who underwent video-assisted thoracic surgery (VATS), were retrospectively collected from June 1st, 2017 to September 30th, 2019. Patients in NIVATS were case-matched with those in intubated video-assisted thoracic surgery (IVATS) by a propensity score-matched analysis. The primary outcome was the comparison of perioperative values, the secondary outcome was the risk factors for postoperative clinical complications (PCP) which were identified by binary logistic regression analysis.

Results: After being matched, there were no differences in demographics and preoperative values of pulmonary function between NIVATS and IVATS groups. The duration of surgery and anesthesia had no difference (P = 0.091 and P = 0.467). As for the postoperative recovery, except for the mean intensive care unit (ICU) stay was longer in the IVATS group than in the NIVATS group (P = 0.015), the chest tube removal time and the postoperative hospital stay had no difference (P = 0.394 and P = 0.453), and the incidence of PCP also had no difference (P = 0.121). The binary logistic regression analysis revealed that the history of pulmonary disease, anesthesia method, and surgical location were risk factors of PCP.

Conclusion: For patients with pulmonary dysfunction when undergoing different types of thoracic procedures, the NIVATS can be performed as effectively and safely as the IVATS, and can reduce the ICU stay.

Thoracic surgery in the non-intubated spontaneously breathing patient

BACKGROUND

The interest in non-intubated video-assisted thoracic surgery (NIVATS) has risen over the last decade and numerous terms have been used to describe this technique. They all have in common, that the surgical procedure is performed in a spontaneously breathing patient under locoregional anaesthesia in combination with intravenous sedation but have also been performed on awake patients without sedation. Evidence has been generated favouring NIVATS compared to one-lung-ventilation under general anaesthesia.

MAIN BODY

We want to give an overview of how NIVATS is performed, and which different techniques are possible. We discuss advantages such as shorter length of hospital stay or (relative) contraindications like airway difficulties. Technical aspects, for instance intraoperative handling of the vagus nerve, are considered from a thoracic surgeon's point of view. Furthermore, special attention is paid to the cohort of patients with interstitial lung diseases, who seem to benefit from NIVATS due to the avoidance of positive pressure ventilation. Whenever a new technique is introduced, it must prove noninferiority to the state of the art. Under this aspect current literature on NIVATS for lung cancer surgery has been reviewed.

CONCLUSION

NIVATS technique may safely be applied to minor, moderate, and major thoracic procedures and is appropriate for a selected group of patients, especially in interstitial lung disease. However, prospective studies are urgently needed.

Non intubated video-assisted thoracoscopic lung resections (NI-VATS) in COVID times

The emergence of epidemic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in December 2019 in Wuhan, China causing Coronavirus Disease 2019 (COVID-19) and its rapid expansion around the world, leading to a global pandemic of dimensions not observed at least since the "Spanish influenza" pandemic in 1917-18, has had great consequences at all levels, including social, health and economic spheres. This pandemic situation forces us, as health care workers, to redefine our medical and surgical actions to adapt them to this new reality. It is important, when the rules of the game change, to rethink and to reevaluate if the balance between risk and benefit have moved to a different point of equilibrium, and if our indications of certain surgical interventions need to be redefined. In this article we try to answer the doubts that arise about the suitability of the NI-VATS technique and assess whether its use in these new pandemic circumstances might add advantages, especially in relation to minimize the risks of virus contagion between patients and all healthcare personnel during the surgical procedure, as well as the known advantages described in many articles the last ten years.

Converting to Intubation During Non-intubated Thoracic Surgery: Incidence, Indication, Technique, and Prevention

Traditionally, intubated general anesthesia with one-lung ventilation is standard in thoracoscopic surgery. However, in recent decades, non-intubated thoracoscopic surgery (NITS) has become an alternative method to minimize the adverse effects of intubated general anesthesia. Non-intubated procedures result in fewer adverse events than tracheal intubation and general anesthesia, such as intubation-related airway injury, ventilation-induced lung injury, prolonged hospital stay, and postoperative nausea and vomiting. Despite these benefits, surgeons must consider the possibility of converting to intubation during NITS as the conversion rate is between 2 and 11%, varying between regions and learning time. The conversion rate is also affected by race, body size, the learning curve, and the surgical team's preferred methods. There are surgical (e.g., significant respiratory movements, uncontrolled bleeding, hindered surgical fields, large tumor sizes, adhesions) and anesthetic (e.g., hypoxemia, hypercapnia, airway spasms) reasons for converting to intubation. When a conversion is deemed necessary by the surgical team, the members should be well-prepared and act rapidly. Anesthesiologists should also feel comfortable intubating patients in the lateral decubitus position with or without bronchoscopic guidance. Patient selection is the key factor for avoiding conversion into an intubated surgery. Patients with an American Society of Anesthesiologists grade 2 or less, a body mass index <25, and less surgical complexity may be good candidates for NITS. Careful monitoring, adequate anesthesia depth, an experienced surgical team, and sufficient preparation can also prevent conversion. Conversion from a non-intubated into intubated thoracic surgery is unwanted but not inevitable. Therefore, NITS can be successful when performed on select patients by a well-prepared and experienced surgical team and is worthy of recommendation owing to its non-invasiveness.

Dimethyl fumarate prevents acute lung injury related cognitive impairment potentially via reducing inflammation

OBJECTIVE

Dimethyl fumarate (DMF) has been reported to exert a protective role against diverse lung diseases and cognitive impairment-related diseases. Thus this study aimed to investigate its role on acute lung injury (ALI) and related cognitive impairment in animal model.

METHODS

C57BL/6 mice were divided into four groups: control group, DMF group, ALI group, and ALI + DMF group. For ALI group, the ALI mice model was created by airway injection of LPS (50 μL, 1 μg/μL); for ALI + DMF group, DMF (dissolved in 0.08% methylcellulose) was treated twice a day for 2 days, and on the third day, mice were injected with LPS for ALI modeling. Mice pre-administered with methylcellulose or DMF without LPS injection (PBS instead) were used as the control group and DMF group, respectively. Morris water maze test was performed before any treatment (0 h) and 6 h after LPS-induction (54 h) to evaluate the cognitive impairment of mice. Next, the brain edema and blood brain barrier (BBB) permeability of ALI mice were assessed by brain water content, Evans blue extravasation and FITC-Dextran uptake assays. In addition, the effect of DMF on the numbers of total cells and neutrophils, protein content in BALF were quantified; the inflammatory factors in BALF, serum, and brain tissues were examined by ELISA, qRT-PCR, and Western blot assays. The effect of DMF on the cognitive impairment-related factor HIF-1α level in lung and brain tissues was also examined by Western blot.

RESULTS

DMF reduced the numbers of total cells, neutrophils and protein content in BALF of ALI mice, inhibited the levels of IL-6, TNF-α and IL-1β in BALF, serum and brain tissues of ALI mice. The protein expressions of p-NF-κB/NF-κB and p-IKBα/IKBα was also suppressed by DMF in ALI mice. Morris water maze test showed that DMF alleviated the cognitive impairment in ALI mice by reducing the escape latency and path length. Moreover, DMF lessened the BBB permeability by decreasing cerebral water content, Evans blue extravasation and FITC-Dextran uptake in ALI mice. The HIF-1α levels in lung and brain tissues of ALI mice were also lessened by DMF.

CONCLUSION

In conclusion, DME had the ability to alleviate the lung injury and cerebral cognitive impairment in ALI model mice. This protective effect partly associated with the suppression of inflammation by DMF.

Extended Pulmonary Resection by Sleeve Lobectomy and Carinal Pneumonectomy: Selection and Technique

Minimally invasive surgical approaches for extended pulmonary resections are becoming increasingly common as more surgeons gain experience in thoracoscopic and robotic technique. Outcome studies demonstrate improved decreased morbidity as compared with an open surgery.

[Intraoperative Ventilation Approaches to One-lung Ventilation]

The management of thoracic surgery patients is challenging to the anesthetist, since one-lung ventilation (OLV) includes at least two major conditions: sufficient oxygenation and lung protection. The first is mainly because the ventilation of one lung is stopped while perfusion to that lung continues; the latter is related to the fact that the whole ventilation is applied to only a single lung. Recommendations for maintaining the oxygenation and methods of lung protection may contradict each other (e. g. high vs. low inspiratory oxygen fraction (FiO₂), high vs. low tidal volume, etc.). Therefore, a high degree of pathophysiological understanding and manual skills are required in the management of these patients.In light of recent clinical studies, this review focuses on a current protective strategy for OLV, which includes a possible decrease in FiO₂, lowered V_T, the application of positive end-expiratory pressure (PEEP) to the dependent and continuous positive airway pressure (CPAP) to the non-dependent lung and alveolar recruitment manoeuvres as well. Other approaches such as the choice of anaesthetics, remote ischemic preconditioning, fluid management and pain therapy can support the success of ventilatory strategy. The present work describes new developments that may change the classical approach in this respect.

COVID-19 After Lung Resection in Northern Italy

We reviewed surgical cases from 4 Thoracic Surgery departments in the Lombardia region of Italy, the area mostly affected by Coronavirus pandemic in Europe, with the aim to describe the impact of COVID-19 on the treatment of thoracic surgical patients. Clinical, radiological and laboratory data from patients who underwent lung resection from December 2019 to March 2020 were retrospectively collected until June 2020. Univariable Cox regression models were estimated to evaluate potential prognostic factors for developing COVID-19 and to investigate postoperative mortality among patients who developed symptomatic COVID-19 infection. We examined data from 107 patients. (74 lobectomies, 32 wedge/segmentectomies and 1 pneumonectomy). Twelve patients developed COVID-19 (Group 1), whereas 95 patients were not infected (Group 2). In Group 1, 6 patients (50%) died from complications related to infection; in Group 2, one patient (1%) died because of non-COVID-19-related causes. Median days from surgery to first symptoms, CT confirmation, clinical confirmation and PCR positivity was 48.1, 54.3, 55.1, and 55.2 respectively. At univariable analysis, DLCO/VA% (P = 0.008), duration of the surgery (P = 0.009), smoking history (pack/year) (P < 0.001), BMI (P< 0.001) and number of segments resected (P = 0.010) were associated with COVID-19 onset. Moreover, CCI (P < 0.001), DLCO/VA% (P = 0.002), cigarette pack/year (P < 0.001), BMI (P < 0.001) and COVID-19 (P < 0.001) were associated with death. Patients who undergo lung resection and then develop symptomatic COVID-19 infection are at higher risk of developing severe respiratory complications and postoperative death. Insidious symptoms’ onset may lead to a delay in diagnosis. We suggest two mitigating strategies: (1) Improve symptoms surveillance and isolation during recovery period, (2) Be aware of a potential greater risk of developing symptomatic COVID-19 and death correlated with elevated CCI, BMI, smoking history, DLCO/VA%, number of resected segments and duration of surgery.

Assessment of lung ultrasound for early detection of respiratory complications in thoracic surgery

BACKGROUND AND OBJECTIVES

To assess lung ultrasound for the diagnosis and monitoring of respiratory complications in thoracic surgery.

METHODS

Prospective observational study in a University hospital, single institution. Adult patients scheduled for pulmonary resection surgery excluding pneumonectomy. An ultrasound follow-up was performed from the day before the surgery to the third day after surgery with calculation of B-line and lung score (reaeration and loss of aeration scores). Respiratory complications were collected throughout the hospitalization period.

RESULTS

Fifty-six patients were included. Eighteen patients presented a respiratory complication (32%), and they presented significantly higher BMI and ASA scores. Patients operated by videothoracoscopy were less at risk of complications. At day 3, a reaeration score ≤ 2 on the ventilated side or ≤ -2 on the operated side, and a B-line score>6 on the operated side were in favor of a complication.

CONCLUSION

Lung ultrasound can help in the diagnosis of respiratory complications following pulmonary resection surgery.

Tidal volume during 1-lung ventilation: A systematic review and meta-analysis

BACKGROUND

The selection of tidal volumes for 1-lung ventilation remains unclear, because there exists a trade-off between oxygenation and risk of lung injury. We conducted a systematic review and meta-analysis to determine how oxygenation, compliance, and clinical outcomes are affected by tidal volume during 1-lung ventilation.

METHODS

A systematic search of MEDLINE and EMBASE was performed. A systematic review and random-effects meta-analysis was conducted. Pooled mean difference estimated arterial oxygen tension, compliance, and length of stay; pooled odds ratio was calculated for composite postoperative pulmonary complications. Risk of bias was determined using the Cochrane risk of bias and Newcastle-Ottawa tools.

RESULTS

Eighteen studies were identified, comprising 3693 total patients. Low tidal volumes (5.6 [±0.9] mL/kg) were not associated with significant differences in partial pressure of oxygen (-15.64 [-88.53-57.26] mm Hg; P = .67), arterial oxygen tension to fractional intake of oxygen ratio (14.71 [-7.83-37.24]; P = .20), or compliance (2.03 [-5.22-9.27] mL/cmH2O; P = .58) versus conventional tidal volume ventilation (8.1 [±3.1] mL/kg). Low versus conventional tidal volume ventilation had no significant impact on hospital length of stay (-0.42 [-1.60-0.77] days; P = .49). Low tidal volumes are associated with significantly decreased odds of pulmonary complications (pooled odds ratio, 0.40 [0.29-0.57]; P < .0001).

CONCLUSIONS

Low tidal volumes during 1-lung ventilation do not worsen oxygenation or compliance. A low tidal volume ventilation strategy during 1-lung ventilation was associated with a significant reduction in postoperative pulmonary complications.

Developing a minimally-invasive anaesthesiological approach to non-intubated uniportal video-assisted thoracoscopic surgery in minor and major thoracic surgery

Background

Non-intubated uniportal video-assisted thoracoscopic surgery (niVATS) is a novel approach to major and minor lung resection. It benefits from a holistic anesthesiological concept with adequate pain relief and sedation in a minimal-invasive setup allowing thoracic procedures under spontaneous breathing. At present no anesthesiological gold standard for niVATS exists. The primary aim of our retrospective observational study was to evaluate feasibility and safety of minimally invasive niVATS for both minor and major pulmonary resections at our institution.

Methods

All 88 consecutive patients scheduled for niVATS minor or major thoracic procedures were included into the study. Anaesthesia was performed according to a departmental niVATS algorithm including both regional anaesthesia and sedation. Patient characteristics and early outcome data including intraoperative and postoperative findings were compared between groups. Prediction scores for postoperative complications (LAS VEGAS, ARISCAT, ThRCRI) were calculated and compared.

Results

No early mortality and a low overall morbidity rate of 28.4% were encountered. Conversion to orotracheal intubation was required in 6.8% of all cases. Postoperative pulmonary complications occurred in 15.9% of total cases and were lower than predicted by both LAS VEGAS and ARISCAT respectively. Cardiac complications were found in 1.1% and lower than predicted by ThRCRI. A persistent air leak occurred in 11.4% of total cases and was significantly higher in major resection. Postoperative chest tube duration and hospital length of stay in the major resection group exceeded times reported by other groups.

Conclusions

niVATS appears to be safe in both minor and major thoracic procedures. A minimally invasive anaesthesiological approach foregoing central iv lines, arterial blood pressure measurement and urinary catheterization is feasible. Our niVATS protocol appears to be a viable alternative for both minor and major thoracic procedures in selected patients.

Effect of Dexmedetomidine on Postoperative Lung Injury during One-Lung Ventilation in Thoracoscopic Surgery

Objective

To investigate the effect of dexmedetomidine on postoperative lung injury in patients undergoing thoracoscopic surgery.

Methods

From March 2019 to October 2019, 40 patients were randomly divided into two groups: dexmedetomidine group (group D) and control group (group C). Except recording the general condition of the patients in both groups preoperatively and intraoperatively, the oxygenation index (OI) and alveolar-arterial oxygen partial pressure difference (A-aDO₂) were monitored at admission (T0), immediately after one-lung ventilation (T1), 0.5 h after one-lung ventilation (T2), and 15 minutes after inhaling air before leaving the room (T3). The content of IL-8 in arterial blood was measured by enzyme-linked immunosorbent assay (ELISA) at T0 and T2, and the expression of AQP1 protein in isolated lung tissue was measured by immunohistochemistry and Western blot. The incidence of postoperative pulmonary complications (atelectasis, pneumonia, and acute respiratory distress syndrome) was used as the index of lung injury.

Results

There was no significant difference in the general condition before and during operation between the two groups. There was no significant difference in arterial blood IL-8 content between the two groups at the T0 time point, but the arterial blood IL-8 content at the T2 time point was significantly higher than that at the T0 time point, especially in group C. The results of immunohistochemistry and Western blot showed that the expression level of AQP1 protein in the isolated lung tissue of group D was significantly higher than that of group C (P < 0 05). At T3, the OI of group D was significantly higher than that of group C, and the A-aDO₂ of group D was significantly lower than that of group C (P < 0.05). There was no significant difference in the incidence of postoperative PPCs between the two groups.

Conclusion

Dexmedetomidine can reduce the level of plasma IL-8 and upregulate the expression of AQP1 in the lung tissue of patients undergoing thoracoscopic surgery under one-lung ventilation, but it has no significant effect on the incidence of postoperative PPCs. Dexmedetomidine can be safely used in thoracoscopic surgery and has a certain protective effect on lung injury.

Nonintubated Versus Intubated Uniportal Thoracoscopic Segmentectomy for Lung Tumors

BACKGROUND

Although the use of the uniportal thoracoscopic technique has spread exponentially recently, a comparison of nonintubated and intubated uniportal thoracoscopic segmentectomies for lung tumors has not been reported. We aimed to compare the feasibility, safety, and short-term postoperative outcomes between the 2 methods.

METHODS

From January 2014 to June 2019 we retrospectively reviewed 185 consecutive patients with lung tumors who underwent uniportal thoracoscopic segmentectomy at our institute. A body mass index of ≥25 kg/m² was considered a contraindication for the nonintubated anesthetic approach. For the remaining cases the anesthetic approach was made at the discretion of each individual anesthesiologist. A propensity-matched analysis incorporating sex and body mass index was used to compare the clinical outcomes of the nonintubated and intubated groups.

RESULTS

Fifty patients (27.0%) underwent the procedure with the nonintubated anesthetic approach. The nonintubated group was more likely to be female (P < .001) and with a lower body mass index (P < .001). Other clinical features showed no significant difference. There was no significant difference between the 2 groups in the type of segmentectomy according to the difficulty classification system. After propensity matching 43 matched patients in each group were included. Anesthetic induction duration (12.0 vs 15.3 minutes, P = .014) was shorter in the nonintubated group. No other significant differences in perioperative, postoperative, and anesthetic results were noted between the 2 matched groups.

CONCLUSIONS

The nonintubated anesthetic approach can be a safe and feasible alternative to intubated uniportal thoracoscopic segmentectomy.

Essential elements of anaesthesia practice in ERAS programs

PURPOSE

Enhanced recovery pathways vary amongst institutions but include key components for anesthesiologists, such as haemodynamic optimization, use of short-acting drugs (and monitoring), postoperative nausea and vomiting (PONV) prophylaxis, protective ventilation, and opioid-sparing multimodal analgesia.

METHODS

After critical appraisal of the literature, studies were selected with particular attention being paid to meta-analyses, randomized controlled trials, and large prospective cohort studies. For each item of the perioperative treatment pathway, available English literature was examined and reviewed.

RESULTS

Patients should be permitted to drink clear fluids up to 2 h before anaesthesia and surgery. Oral carbohydrate loading should be used routinely. All patients may have an individualized plan for fluid and haemodynamic management that matches the monitoring needs with patient and surgical risk. Minimizing the side effects of anaesthetics and analgesics using short-acting drugs with careful perioperative monitoring should be encouraged. Protective ventilation with alveolar recruitment maneuvers is required. Preventive use of a combination with 2-3 antiemetics in addition to propofol-based total intravenous anaesthesia (TIVA) is most likely to reduce PONV. While the ideal analgesia regimen remains to be determined, it is clear that a multimodal opioid-sparing analgesic strategy has significant benefits.

CONCLUSION

Careful evaluation of single patient and planning of the anesthetic care are mandatory to join the ERAS philosophy. Optimal fluid management, use of short-acting drugs, prevention of PONV, protective ventilation, and multimodal analgesia are the cornerstones of the anaesthesia management within ERAS protocols.

Lung Collapse during Mini-Thoracotomy Reduces Penetration of Cefuroxime to the Tissue: Interstitial Microdialysis Study in Animal Models

Background: Single-lung ventilation facilitates surgical exposure during minimally invasive cardiac surgery. However, a deeper knowledge of antibiotic distribution within a collapsed lung is necessary for effective antibiotic prophylaxis of pneumonia. Patients and Methods: The pharmacokinetics/pharmacodynamics (PK/PD) of cefuroxime were compared between the plasma and interstitial fluid (ISF) of collapsed and ventilated lungs in 10 anesthetized pigs, which were ventilated through a double-lumen endotracheal cannula. Cefuroxime (20 mg/kg) was administered in single 30-minute intravenous infusion. Samples of blood and lung microdialysate were collected until six hours post-dose. Ultrafiltration, in vivo retrodialysis, and high-performance liquid chromatography-tandem mass spectrometry were used to determine plasma and ISF concentrations of free drug. The concentrations were examined with non-compartmental analysis and compartmental modeling. Results: The concentration of free cefuroxime in ISF was lower in the non-ventilated lung than the ventilated one, evidenced by a lung penetration factor of 47% versus 63% (p < 0.05), the ratio between maximum concentrations (65%, p < 0.05), and the ratio between the areas under the concentration-time curve (78%, p = 0.12). The time needed to reach a minimum inhibitory concentration (MIC) was 30%-40% longer for a collapsed lung than for a ventilated one. In addition, a delay of 10-40 minutes was observed for lung ISF compared with plasma. The mean residence time values (ISF collapsed lung > ISF ventilated lung > plasma) could explain the absence of practically important differences in the time interval with the concentration of cefuroxime exceeding the MICs of sensitive strains (≤4 mg/L). Conclusion: The concentration of cefuroxime in the ISF of a collapsed porcine lung is lower than in a ventilated one; furthermore, its equilibration with plasma is delayed. Administration of the first cefuroxime dose earlier or at a higher rate may be warranted, as well as dose intensification of the perioperative prophylaxis of pneumonia caused by pathogens with higher MICs.

Body Position Alters Mechanical Power and Respiratory Mechanics During Thoracic Surgery

BACKGROUND

During thoracic surgery, patients are usually positioned in lateral decubitus and only the dependent lung ventilated. The ventilated lung is thus exposed to the weight of the contralateral hemithorax and restriction of the dependent chest wall. We hypothesized that mechanical power would increase during one-lung ventilation in the lateral position.

METHODS

We performed a prospective, observational, single-center study from December 2016 to May 2017. Thirty consecutive patients undergoing general anesthesia with mechanical ventilation (mean age, 68 ± 11 years; body mass index, 25 ± 5 kg·m) for thoracic surgery were enrolled. Total and partitioned mechanical power, lung and chest wall elastance, and esophageal pressure were compared in supine and lateral position with double- and one-lung ventilation and with closed and open chest both before and after surgery. Mixed factorial ANOVA for repeated measurements was performed, with both step and the period before or after surgery as 2 within-subject factors, and left or right body position during surgery as a fixed, between-subject factor. Appropriate interaction terms were included.

RESULTS

The mechanical power was higher in lateral one-lung ventilation compared to both supine and lateral position double-lung ventilation (11.1 ± 3.0 vs 8.2 ± 2.7 vs 8.7 ± 2.6; mean difference, 2.9 J·minute [95% CI, 1.4-4.4 J·minute] and 2.4 J·minute [95% CI, 0.9-3.9 J·minute]; P < .001 and P = .002, respectively). Lung elastance was higher during lateral position one-lung ventilation compared to both lateral and supine double-lung ventilation (24.3 ± 8.7 vs 9.5 ± 3.8 vs 10.0 ± 3.8; mean difference, 14.7 cm H2O·L [95% CI, 11.2-18.2 cm H2O·L] and 14.2 cm H2O·L [95% CI, 10.8-17.7 cm H2O·L], respectively) and was higher compared to predicted values (20.1 ± 7.5 cm H2O·L). Chest wall elastance increased in lateral position double-lung ventilation compared to supine (11.1 ± 3.8 vs 6.6 ± 3.4; mean difference, 4.5 cm H2O·L [95% CI, 2.6-6.3 cm H2O·L]) and was lower in lateral position one-lung ventilation with open chest than with a closed chest (3.5 ± 1.9 vs 7.1 ± 2.8; mean difference, 3.6 cm H2O·L [95% CI, 2.4-4.8 cm H2O·L]). The end-expiratory esophageal pressure decreased moving from supine position to lateral position one-lung ventilation while increased with the opening of the chest wall.

CONCLUSIONS

Mechanical power and lung elastance are increased in the lateral position with one-lung ventilation. Esophageal pressure monitoring may be used to follow these changes.

Thoracoscopic lung biopsy under regional anesthesia for interstitial lung disease

BACKGROUND

Interstitial lung disease (ILD) management guidelines support lung biopsy-guided therapy. However, the high mortality associated with thoracoscopic lung biopsy using general anesthesia (GA) in patients with ILD has deterred physicians from offering this procedure and adopt a diagnostic approach based on high-resolution CT. Here we report that thoracoscopy under regional anesthesia could be a safer alternative for lung biopsy and effectively guide ILD treatment.

METHODS

This was a single-center retrospective review of prospectively maintained database and consisted of patients who underwent thoracoscopic lung biopsy between March 2016 and March 2018. Patients were divided into two groups: (A) GA, and (B) regional anesthesia using monitored anesthesia care (MAC) and thoracic epidural anesthesia (TEA).

RESULTS

During the study period, 44 patients underwent thoracoscopic lung biopsy. Of these, 15 underwent MAC/TEA. There were no significant differences between the two groups with regard to pulmonary function test and clinicodemographic profile. However, operative time and hospital stay were shorter in MAC/TEA group (32.5±18.5 min vs 50.8±18.4; p=0.004, 1.0±1.3 days vs 10.0±34.7 days; p<0.001, respectively). Eight patients in the GA group, but none in the MAC/TEA group, experienced worsening of ILD after lung biopsy (p=0.03). Additionally, one patient in the GA group died due to acute ILD worsening. No cases of MAC/TEA group had to be converted to GA. In all cases a pathological diagnosis could be made.

CONCLUSIONS

Thoracoscopy using regional anesthesia might be a safer alternative to lung biopsy in patients with ILD.

Mechanically ventilated patients exhibit decreased particle flow in exhaled breath as compared to normal breathing patients

Introduction

In this cohort study, we evaluated whether the particles in exhaled air (PExA) device can be used in conjunction with mechanical ventilation during surgery. The PExA device consists of an optical particle counter and an impactor that collects particles in exhaled air. Our aim was to establish the feasibility of the PExA device in combination with mechanical ventilation (MV) during surgery and if collected particles could be analysed. Patients with and without nonsmall cell lung cancer (NSCLC) undergoing lung surgery were compared to normal breathing (NB) patients with NSCLC.

Methods

A total of 32 patients were included, 17 patients with NSCLC (MV-NSCLC), nine patients without NSCLC (MV-C) and six patients with NSCLC and not intubated (NB). The PEx samples were analysed for the most common phospholipids in surfactant using liquid-chromatography-mass-spectrometry (LCMS).

Results

MV-NSCLC and MV-C had significantly lower numbers of particles exhaled per minute (particle flow rate; PFR) compared to NB. MV-NSCLC and MV-C also had a siginificantly lower amount of phospholipids in PEx when compared to NB. MV-NSCLC had a significantly lower amount of surfactant A compared to NB.

Conclusion

We have established the feasibility of the PExA device. Particles could be collected and analysed. We observed lower PFR from MV compared to NB. High PFR during MV may be due to more frequent opening and closing of the airways, known to be harmful to the lung. Online use of the PExA device might be used to monitor and personalise settings for mechanical ventilation to lower the risk of lung damage.

The PExA device is safe to use in conjunction with mechanical ventilation during surgery, and can measure and collect particles in exhaled air for subsequent biochemical analysishttp://bit.ly/2ofo6gw

Uniportal VATS for non-small cell lung cancer

The video-assisted thoracic surgery (VATS) technique has evolved from its multiport origins to even less invasive approaches grounded in its proven benefits over open surgery for the treatment of early stage lung cancer. In this evolution process, the Uniportal VATS (UniVATS) strategy emerged. This technique is giving some evidence of benefits when compared to the multiport VATS and has been embraced by the surgical community spreading its geographical and surgical boundaries. Moreover, UniVATS has proven its feasibility for numerous and more complex procedures for lung cancer diagnosis and treatment, which are reviewed in this document as well as its current and future development.

Protective effects of hesperetin on lipopolysaccharide-induced acute lung injury in a rat model

BACKGROUND

In this experimental study, we aimed to investigate the effects of hesperetin, a natural flavonoid, on a lipopolysaccharideinduced acute lung injury model in rats.

METHODS

Between March 2019 and May 2019, a total of 18 adult male Wistar albino rats, weighing approximately 250 to 300 g, were randomly divided into three groups as control, lipopolysaccharide, and lipopolysaccharide + hesperetin groups (n=6 in each group). The wet/dry weight ratio of lung tissue was determined. Histopathological changes were examined using light and scanning electron microscopy. Pulmonary nuclear factor-kappa beta, inducible nitric oxide synthase, and alpha-smooth muscle antigen activity were determined with indirect immunohistochemical methods. Pulmonary apoptosis was detected with the terminal deoxynucleotidyl transferase dUTP nick-end labeling method. Tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6, and interleukin-10 concentrations were measured with enzyme-linked immunosorbent assay.

RESULTS

Treatment with hesperetin significantly improved the architecture of lung tissue and reduced the wet/dry weight ratio, nuclear factor-kappa beta, inducible nitric oxide synthase, and alphasmooth muscle antigen expression, pulmonary apoptosis, and levels of proinflammatory cytokines.

CONCLUSION

Our study results suggest that hesperetin has a potent protective effect against lipopolysaccharide-induced acute lung injury in rats via suppression of the proinflammatory cytokine cascade, nuclear factor-kappa beta, signaling pathway activation, and apoptosis.

Rationale and design of PASSAT - patients' satisfaction with local or general anaesthesia in video-assisted thoracoscopic surgery: study protocol for a randomised controlled trial with a non-randomised side arm

BACKGROUND

Although general anaesthesia (GA) with one-lung ventilation is the current standard of care, minor thoracoscopic surgery, i.e. treatment of pleural effusions, biopsies and small peripheral pulmonary wedge resections, can also be performed using local anaesthesia (LA), analgosedation and spontaneous breathing. Whilst the feasibility and safety of LA have been demonstrated, its impact on patient satisfaction remains unclear. Most studies evaluating patient satisfaction lack control groups or do not meet psychometric criteria. We report the design of the PASSAT trial (PAtientS' SATisfaction in thoracic surgery - general vs. local anaesthesia), a randomised controlled trial with a non-randomised side arm.

METHODS

Patients presenting for minor thoracoscopic surgery and physical eligibility for GA and LA are randomised to surgery under GA (control group) or LA (intervention group). Those who refuse to be randomised are asked to attend the study on the basis of their own choice of anaesthesia (preference arm) and will be analysed separately. The primary endpoint is patient satisfaction according to a psychometrically validated questionnaire; secondary endpoints are complication rates, capnometry, actual costs and cost effectiveness. The study ends after inclusion of 54 patients in each of the two randomised study groups.

DISCUSSION

The PASSAT study is the first randomised controlled trial to systematically assess patients' satisfaction depending on LA or GA. The study follows an interdisciplinary approach, and its results may also be applicable to other surgical disciplines. It is also the first cost study based on randomised samples. Comparison of the randomised and the non-randomised groups may contribute to satisfaction research.

TRIAL REGISTRATION

German Clinical Trials Register, DRKS00013661 . Registered on 23 March 2018.

Posttreatment With the Fatty Acid Amide Hydrolase Inhibitor URB937 Ameliorates One-Lung Ventilation-Induced Lung Injury in a Rabbit Model

BACKGROUND

One-lung ventilation (OLV)-induced inflammation is a risk factor for acute lung injury that is responsible for 20% of postoperative pulmonary complications after lung resection. Inflammation is an important trigger for acute lung injury. Fatty acid amide hydrolase (FAAH) is the major enzyme that degrades the endocannabinoid arachidonoylethanolamine (AEA), an important regulator of inflammation, and its downstream metabolites such as arachidonic acid (AA) are also involved in inflammation. Importantly, AEA is also found in lung parenchyma. However, it remains unclear whether pharmacological inhibition of FAAH inhibitor using compounds such as URB937 can attenuate OLV-induced lung injury.

MATERIALS AND METHODS

New Zealand white rabbits were anesthetized to establish a modified OLV-induced lung injury model. Twenty-four male rabbits were randomly divided into four groups (n = 6): TLV-S (2.5-h two-lung ventilation [TLV] + 1.5 mL/kg saline + 1-h TLV), OLV-S (2.5-h OLV + 1.5 mL/kg saline + 0.5-h OLV + 0.5-h TLV), U-OLV (1.5 mL/kg URB937 + 3.0-h OLV + 0.5-h TLV), and OLV-U (2.5-h OLV + 1.5 mL/kg URB937 + 0.5-h OLV + 0.5-h TLV). Arterial blood gases, lung wet/dry ratio, and lung injury score of the nonventilated lungs were measured. The levels of AEA, AA, prostaglandin I2 (PGI2), thromboxane A2 (TXA2), and leukotriene B4 (LTB4) in the nonventilated lung were also quantified.

RESULTS

The arterial oxygenation index (PaO₂/FiO₂) decreased after 0.5-h OLV in the three OLV groups. The PaO₂/FiO₂ in the OLV-U group was better than that in the OLV-S and U-OLV groups and was accompanied with reductions in the wet/dry ratio and lung injury scores of the nonventilated lungs. The FAAH inhibitor URB937 administered not before but 2.5 h after OLV attenuated OLV-induced lung injury by increasing AEA levels and reducing the levels of downstream metabolites including AA, PGI2, TXA2, and LTB4.

CONCLUSIONS

Posttreatment with the FAAH inhibitor URB937 attenuated OLV-induced lung injury in rabbits and was associated with increased AEA levels and decreased levels of AA and its downstream metabolites.

Non-intubated thoracoscopic surgery for lung cancer in patients with impaired pulmonary function

Background

Patients with impaired lung function or chronic obstructive pulmonary disease (COPD) are considered high-risk for intubated general anesthesia, which may preclude them from surgical treatment of their lung cancers. We evaluated the feasibility of non-intubated video-assisted thoracoscopic surgery (VATS) for the surgical management of lung cancer in patients with impaired pulmonary function.

Methods

From August 2009 to June 2015, 28 patients with impaired lung function (preoperative forced expiratory volume in 1 second <70% of the predicted value) underwent non-intubated VATS using a combination of thoracic epidural anesthesia or intercostal nerve block, and intra-thoracic vagal block with target-controlled sedation.

Results

Eighteen patients had primary lung cancers, 4 had metastatic lung cancers, and 6 had non-malignant lung tumors. In the patients with primary lung cancer, lobectomy was performed in 4, segmentectomy in 3 and wedge resection in 11, with lymph node sampling adequate for staging. One patient required conversion to intubated one-lung ventilation because of persistent wheezing and labored breathing. Five patients developed air leaks more than 5 days postoperatively while subcutaneous emphysema occurred in 6 patients. Two patients developed acute exacerbations of pre-existing COPD, and new-onset atrial fibrillation after surgery occurred in 1 patient. The median duration of postoperative chest tube drainage was 3 days while the median hospital stay was 6 days.

Conclusions

Non-intubated VATS resection for pulmonary tumors is technically feasible. It may be applied as an alternative to intubated general anesthesia in managing lung cancer in selected patients with impaired pulmonary function.

Application of alveolar recruitment strategy and positive end-expiratory pressure combined with autoflow in the one-lung ventilation during thoracic surgery in obese patients

Background

The present study aims to evaluate the influence of alveolar recruitment strategy (ARS) and positive end-expiratory pressure (PEEP) combined with autoflow on respiratory mechanics, the oxygen index (OI), pulmonary shut [Qs/Qt(%)], and the concentrations of IL-6 and TNF-α in venous blood after surgery in obese patients who experienced thoracic surgery with one-lung ventilation (OLV).

Methods

A total of 36 obese patients with ASAII-III degree, who experienced selective pulmonary lobectomy, were within 36-74 years old, and had a BMI of 30-40 kg/m², were randomly divided into two groups: control group (C group) and protective ventilation group (P group). In the P group, ARS was given once when OLV began. Then, ventilation at 7 mmHg of PEEP and autoflow were given. The P_peak before OLV (T₁), at 30 minutes after OLV (T₂), and at the 5 minutes after two-lung ventilation (TLV) (T₃), and the changes of P_plat and Cdyn were recorded. Then, arteriovenous blood was drawn at T₁, T₂, T₃ and T₄ (6 hours after the operation), blood-gas indicators, including SPO₂, PaCO₂ and PaO₂, were measured, and the value of Qs/Qt(%) was calculated. Afterwards, venous blood was collected at T₁ and T₅ (18 hours after surgery), and the concentrations of IL-6 and TNF-α were detected. The clinical pulmonary infection score (CPIS) was determined at the first day and seventh day after the operation.

Results

In both groups, Cdyn and OI decreased, while P_plat, P_peak and Qs/Qt(%) increased (P<0.05) at T₂, when compared with those at T₁. At T₂ and T₃, P_plat and P_peak decreased (P<0.05) in the P group, when compared with the C group. At T₂, T₃ and T₄, OI increased (P<0.05) in the P group, when compared with the C group. At T₂, T₃ and T₄, PaCO₂ and Qs/Qt(%) decreased in the P group, when compared with the C group. The concentrations of IL-6 and TNF-α decreased in the P group, when compared with the C group.

Conclusions

The ventilation model of ARS and PEEP combined with autoflow can better reduce airway pressure and the production of injurious inflammatory cytokines in blood in obese patients. Furthermore, it can reduce Qs/Qt during and at 6 hours after thoracotomy, improve OI and maintain the acid-base balance of the internal environment, which may be applied in clinical work. This brings new enlightenment and needs to be clarified through further studies.

Can apneic oxygen insufflation become a novel lung protective ventilation strategy? A randomized, controlled, blinded, single center clinical trial

Objective

The aim of this study was to determine whether a AOI strategy on non-ventilated lung could reduce the regional and systemic proinflammatory cytokine and oxidative stress response associated with esophagectomy, and to evaluate whether AOI can be used as a novel lung protective ventilation strategy. Its impact on oxygenation after OLV, surfactant protein A, B, C (SP-A, B, C), postoperative hospital stay and postoperative pulmonary complications (PPCs) was also evaluated.

Methods

Fifty-four adults (ASA II-III) undergoing esophagectomy with OLV were enrolled in the study. Patients were randomly assigned into 2 groups: control group (group C) and treated group (group T). Group C was treated with traditional OLV mode,while group T was given AOI of 5 L/min oxygen on the non-ventilated lung immediately at the beginning of OLV. Arterial blood gas was analyzed before and after OLV. A bronchoalveolar lavage(BAL) was performed after OLV on the non-ventilated lung. Proinflammatory cytokine, oxidative stress markers(TNF-α, NF-κB,sICAM-1,IL-6,IL-10,SOD,MDA) and SP-A, B, C were analyzed in serum and BALF as the primary endpoint.The clinical outcome determined by PPCs was assessed as the secondary endpoint.

Results

Patients with AOI had better oxygenation in the recovery period, oxygenation index(OI) (394[367–426] and 478[440–497]mmHg, respectively) of group T at T₂ and T₃ were significantly higher than those (332[206–434] and 437[331–512]mmHg, respectively) of group C. OLV resulted in an increase in the measured inflammatory markers in both groups, however, the increase of inflammatory markers upon OLV in the group C was significantly higher than those of group T. OLV resulted in an increase in the measured SP-A, B, C in serum of both groups. However, the levels of SP-A, B, C of group T were lower than those of group C in serum after OLV, and the results in BALF were the opposite. The BALF levels of SOD(23.88[14.70–33.93]U/ml) of group T were higher than those(15.99[10.33–24.16] U/ml) of group C, while the levels of MDA in both serum and BALF of group T(8.60[4.14–9.85] and 1.88[1.33–3.08]nmol/ml, respectively) were all lower than those of group C (11.10[6.57–13.75] and 1.280[1.01–1.83]nmol/ml) after OLV. There was no statistical difference between the two groups in terms of postoperative hospital stay and the incidence of PPCs.

Conclusion

AOI on non-ventilated lung during OLV can improve the oxygenation function after OLV, relieve the inflammatory and oxidative stress response in the systemic and non-ventilated lung after OLV associated with esophagectomy.

Trial registration

ChiCTR-IOR-17011037. Registered on 31 March 2017.

The Potential Dangers of Recruitment Maneuvers During One Lung Ventilation Surgery

BACKGROUND

Existing evidence regarding lung-protective ventilation (LPV) during one-lung ventilation (OLV) focuses on surrogate outcomes. Our objective was to assess whether an LPV protocol during OLV surgery is associated with reduced respiratory complications.

MATERIALS AND METHODS

This was a matched control retrospective cohort study of patients undergoing pulmonary resection at a tertiary Canadian hospital. The experimental group (n = 50) was derived from primary data of two crossover RCTs, which utilized protocolized LPV strategies with varying levels of positive end-expiratory pressure and recruitment maneuvers. The control group was drawn from a prospectively maintained database; these patients received conventional nonprotocolized ventilation (2000-2010). Each experimental group patient was matched 1:1 with a control group patient with respect to clinically relevant variables (age, sex, diagnosis, smoking status, cardiovascular disease status, comorbidity, BMI, preoperative forced expiratory volume in 1 s, surgery type). Major respiratory complications were defined as composite of acute respiratory distress syndrome, need for new positive-pressure ventilation, and atelectasis requiring bronchoscopy. Paired and unpaired statistical tests were used.

RESULTS

Patients appeared well matched. Major respiratory complications occurred in 8% (n = 4) and 2% (n = 1) of patients in experimental and control groups, respectively (P = 0.50). There was a trend toward increased mortality (4 versus 0, P = 0.06) with protocolized LPV. The patients who died had respiratory complications; one had acute respiratory distress syndrome and two had profound hypoxemia.

CONCLUSIONS

There was a nonsignificant trend toward increased mortality with LPV during OLV. Although limited by a small sample size, our findings identify a potential danger to excessive recruitment maneuvers. Larger studies, with clinically important outcomes are needed to better define the risk/benefit trade-offs for LPV during OLV.

Sevoflurane attenuates ventilator‑induced lung injury by regulating c‑PLA2 expression

The aim of the present study was to investigate the potential role of club cell secretory protein (CCSP), an endogenous modulator, in reducing pulmonary inflammation induced by sevoflurane following one‑lung ventilation (OLV). Healthy Japanese white rabbits were randomly assigned to six groups: Sham‑operated group (group S); respiratory management of OLV group (group O); OLV + sevoflurane treated group (group OF), club cells exfoliated + sham‑operated group (group NA), club cells exfoliated + OLV group (group NAO); and club cells exfoliated + OLV + sevoflurane treated group (group NAOF). At the end of the experimental observation, all animals in the different groups were sacrificed and lung injury was evaluated according to the lung wet/dry weight ratio and histological scoring system. Lung homogenates were harvested to detect the mRNA and protein expression of cytosolic phospholipase A2 (c‑PLA2) and CCSP. The content of arachidonic acid was measured using an ELISA. Following OLV treatment, c‑PLA2 expression was increased, CCSP expression was decreased and lung injury scores were significantly increased. Sevoflurane inhalation in the OLV‑treated group induced an upregulation of CCSP and a downregulation of c‑PLA2 expression. In the group NAO, in which the club cells were simultaneously exfoliated, OLV caused more severe lung damage and induced higher expression of c‑PLA2 compared with that in group O. However, sevoflurane inhalation reduced the extent of lung injury and the expression of c‑PLA2, even when the endogenous modulator of lung inflammation, CCSP, was exfoliated (group NAOF). These results indicated that OLV promoted lung inflammation through the CCSP and c‑PLA2 pathway. However, the results from the club cells exfoliated group indicated that the CCSP may not be involved in the protective effect exerted by sevoflurane inhalation.

Effect of lung protective ventilation on coronary heart disease patients undergoing lung cancer resection

Background

Mechanical ventilation, especially large tidal volume (Vt) one-lung ventilation (OLV), can cause ventilator-induced lung injury (VILI) that can stimulate cytokines. Meanwhile, cytokines are considered very important factor influencing coronary heart disease (CHD) patient prognosis. So minimization of pulmonary inflammatory responses by reduction of cytokine levels for CHD undergoing lung resection during OLV should be a priority. Because previous studies have demonstrated that lung-protective ventilation (LPV) reduced lung inflammation, this ventilation approach was studied for CHD patients undergoing lung resection here to evaluate the effects of LPV on pulmonary inflammatory responses.

Methods

This is a single center, randomized controlled trial. Primary endpoint of the study are plasma concentrations of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-10 and C-reactive protein (CRP). Secondary endpoints include respiratory variables and hemodynamic variables. 60 CHD patients undergoing video-assisted thoracoscopic lung resection were randomly divided into conventional ventilation group [10 mL/kg Vt and 0 cmH₂O positive end-expiratory pressure (PEEP), C group] and protective ventilation group (6 mL/kg Vt and 6 cmH₂O PEEP, P group; 30 patients/group). Hemodynamic variables, peak inspiratory pressure (Ppeak), dynamic compliance (Cdyn), arterial oxygen tension (PaO₂) and arterial carbon dioxide tension (PaCO₂) were recorded as test data at three time points: T1-endotracheal intubation for two-lung ventilation (TLV) when breathing and hemodynamics were stable; T2-after TLV was substituted with OLV when breathing and hemodynamics were stable; T3-OLV was substituted with TLV at the end of surgery when breathing and hemodynamics were stable. The concentrations of TNF-α, IL-6, IL-10 and CRP in patients' blood in both groups at the very beginning of OLV (beginning of OLV) and the end moment of the surgery (end of surgery) were measured.

Results

The P group exhibited greater PaO₂, higher Cdyn and lower Ppeak than the C group at T2, T3 (P<0.05). At the end moment of the surgery, although the P group tended to exhibit higher TNF-α and IL-10 values than the C group, the differences did not reach statistical significance(P=0.0817, P=0.0635). Compared with C group at the end moment of the surgery, IL-6 and CRP were lower in P group, the differences were statistically significant (P=0.0093, P=0.0005). There were no significant differences in hemodynamic variables between the two groups (P>0.05).

Conclusions

LPV can effectively reduce the airway pressure, improve Cdyn and PaO₂, reduce concentrations of IL-6 and CRP during lung resection of CHD patients.Trial registration: The trial was registered in the Chinese Clinical Trial Registry.

Minimally invasive thoracic surgery: beyond surgical access

Thoracic surgery has evolved throughout the decades. The difficulty of accessing the intrathoracic organs through the bony rib-cage has been a challenge for thoracic surgeons. In the past, large incisions stretching across the chest, such as posterolateral thoracotomies with rib spreading was the standard approach to access the lungs. These methods cause large amounts of trauma to the patient, with high rates of mortality and morbidity. However, with the advances in technology and the improvements in surgical technique, thoracic surgery has progressed to minimise trauma to the patient while still maintaining oncological and surgical principles. State-of-the-art technology, combined with wide variety of old and new surgical techniques give the thoracic surgeon a formidable armamentarium. Although there has been a focus on reducing the number and size of surgical wounds, considerations other than surgical approach can reduce the trauma suffered by the patient. Preservation of pulmonary function via organ preservation and anaesthetic techniques to further minimise the systemic inflammation such as non-intubated anaesthesia have also been shown to improve patient outcomes. This article aims to review the recent advances in minimally invasive thoracic surgery.

Nonintubated-Awake Anesthesia for Uniportal Video-Assisted Thoracic Surgery Procedures

Nonintubated video-assisted thoracic surgery (VATS) strategies are gaining popularity. This review focuses on noninutbated VATS, and discusses advantages, indications, anesthetic techniques, and approaches to intraoperative crisis management. Advances in endoscopic, endovascular, and robotic techniques have expanded the range of surgical procedures that can be performed in a minimally invasive fashion. The nonintubated thoracoscopic approach has been adapted for use with major lung resections. The need for general anesthesia and endotracheal intubation has been reexamined, such that regional or epidural analgesia may be sufficient for cases where lung collapse can be accomplished with spontaneous ventilation and an open hemithorax.

Heparin-free extracorporeal membrane oxygenation in a patient with severe pulmonary contusions and bronchial disruption

Pulmonary contusion complicated with endobronchial hemorrhage is potentially life-threatening, particularly in patients with tracheobronchial tree disruption and severe airway bleeding after blunt trauma, and pose a high mortality risk. In such cases, extracorporeal membrane oxygenation (ECMO) can be used as a salvage treatment modality. However, the use of ECMO for moribund trauma patients with respiratory failure may be limited for several reasons, such as intractable bleeding. In this case report, we describe a patient with severe bilateral pulmonary contusions with tracheobronchial tree disruption that was successfully treated using heparin-free venovenous ECMO.

New evidence in one-lung ventilation

Mechanical ventilation in thoracic surgery has undergone significant changes in recent years due to the implementation of the protective ventilation. This review will analyze recent ventilatory strategies in one-lung ventilation. A MEDLINE research was performed using Mesh term "One-Lung Ventilation" including randomized clinical trials, metanalysis, reviews and systematic reviews published in the last 6 years. Search was performed on 21st March 2017. A total of 75 articles were initially found. After title and abstract review 14 articles were included. Protective ventilation is not simply synonymous of low tidal volume ventilation, but it also includes routine use of PEEP and alveolar recruitment maneuver. New techniques are still in discussion namely PEEP adjustment, ratio inspiration:expiration, ideal type of anesthesia during one-lung ventilation and hypercapnic ventilation.