The pulmonary physician in critical care * 7: ventilator induced lung injury

The ARDS microenvironment enhances MSC-induced repair via VEGF in experimental acute lung inflammation

Clinical trials investigating the potential of mesenchymal stromal cells (MSCs) for the treatment of inflammatory diseases, such as acute respiratory distress syndrome (ARDS), have been disappointing, with less than 50% of patients responding to treatment. Licensed MSCs show enhanced therapeutic efficacy in response to cytokine-mediated activation signals. There are two distinct sub-phenotypes of ARDS: hypo- and hyper-inflammatory. We hypothesized that pre-licensing MSCs in a hyper-inflammatory ARDS environment would enhance their therapeutic efficacy in acute lung inflammation (ALI). Serum samples from patients with ARDS were segregated into hypo- and hyper-inflammatory categories based on interleukin (IL)-6 levels. MSCs were licensed with pooled serum from patients with hypo- or hyper-inflammatory ARDS or healthy serum controls. Our findings show that hyper-inflammatory ARDS pre-licensed MSC conditioned medium (MSC-CMHyper) led to a significant enrichment in tight junction expression and enhanced barrier integrity in lung epithelial cells in vitro and in vivo in a vascular endothelial growth factor (VEGF)-dependent manner. Importantly, while both MSC-CMHypo and MSC-CMHyper significantly reduced IL-6 and tumor necrosis factor alpha (TNF-α) levels in the bronchoalveolar lavage fluid (BALF) of lipopolysaccharide (LPS)-induced ALI mice, only MSC-CMHyper significantly reduced lung permeability and overall clinical outcomes including weight loss and clinical score. Thus, the hypo- and hyper-inflammatory ARDS environments may differentially influence MSC cytoprotective and immunomodulatory functions.

Trends in the Incidence of Bronchopulmonary Dysplasia after the Introduction of Neurally Adjusted Ventilatory Assist (NAVA)

OBJECTIVE

This study investigates the difference in the rates of bronchopulmonary dysplasia in very low birth weight infants before and after the introduction of neurally adjusted ventilatory assist (NAVA).

STUDY DESIGN

A retrospective cohort study comparing rates of Bronchopulmonary dysplasia (BPD) before and after implementation of NAVA. Eligibility criteria included all very low birth weight VLBW neonates needing ventilation. For analysis, each cohort was divided into three subgroups based on gestational age. Changes in the rate of BPD, length of stay, tracheostomy rates, invasive ventilator days, and home oxygen therapy were compared.

RESULTS

There were no differences in the incidence of BPD in neonates at 23-25 6/7 weeks' and 29-32 weeks' gestation between the two cohorts. A higher incidence of BPD was seen in the 26-28 5/7 weeks' gestation NAVA subgroup compared to controls (86% vs. 68%, p = 0.05). No significant difference was found for ventilator days, but infants in the 26-28 6/7 subgroup in the NAVA cohort had a longer length of stay (98 ± 34 days vs. 82 ± 24 days, p = 0.02), a higher percentage discharged on home oxygen therapy (45% vs. 18%, respectively, p = 0.006), and higher tracheostomy rates (3/36 vs. 0/60, p = 0.02), compared to the control group.

CONCLUSIONS

The NAVA mode was not associated with a reduction in BPD when compared to other modes of ventilation. Unexpected increases were seen in BPD rates, home oxygen therapy rates, tracheostomy rates, and the length of stay in the NAVA subgroup born at 26-28 6/7 weeks' gestation.

The role of oxygen in the development and treatment of bronchopulmonary dysplasia

Oxygen (O2) is crucial for both the development and treatment of one of the most important consequences of prematurity: bronchopulmonary dysplasia (BPD). In fetal life, the hypoxic environment is important for alveolar development and maturation. After birth, O2 becomes a double-edged sword. While O2 is needed to prevent hypoxia, it also causes oxidative stress leading to a plethora of morbidities, including retinopathy and BPD. The advent of continuous O2 monitoring with pulse oximeters has allowed clinicians to recognize the narrow therapeutic margins of oxygenation for the preterm infant, but more knowledge is needed to understand what these ranges are at different stages of the preterm infant's life, including at birth, in the neonatal intensive care unit and after hospital discharge. Future research, especially in innovative technologies such as automated O2 control and remote oximetry, will improve the understanding and treatment of the O2 needs of infants with BPD.

Higher versus lower fractions of inspired oxygen or targets of arterial oxygenation for adults admitted to the intensive care unit

BACKGROUND

This is an updated review concerning 'Higher versus lower fractions of inspired oxygen or targets of arterial oxygenation for adults admitted to the intensive care unit'. Supplementary oxygen is provided to most patients in intensive care units (ICUs) to prevent global and organ hypoxia (inadequate oxygen levels). Oxygen has been administered liberally, resulting in high proportions of patients with hyperoxemia (exposure of tissues to abnormally high concentrations of oxygen). This has been associated with increased mortality and morbidity in some settings, but not in others. Thus far, only limited data have been available to inform clinical practice guidelines, and the optimum oxygenation target for ICU patients is uncertain. Because of the publication of new trial evidence, we have updated this review.

OBJECTIVES

To update the assessment of benefits and harms of higher versus lower fractions of inspired oxygen (FiO2) or targets of arterial oxygenation for adults admitted to the ICU.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Science Citation Index Expanded, BIOSIS Previews, and LILACS. We searched for ongoing or unpublished trials in clinical trial registers and scanned the reference lists and citations of included trials. Literature searches for this updated review were conducted in November 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared higher versus lower FiO2 or targets of arterial oxygenation (partial pressure of oxygen (PaO2), peripheral or arterial oxygen saturation (SpO2 or SaO2)) for adults admitted to the ICU. We included trials irrespective of publication type, publication status, and language. We excluded trials randomising participants to hypoxaemia (FiO2 below 0.21, SaO2/SpO2 below 80%, or PaO2 below 6 kPa) or to hyperbaric oxygen, and cross-over trials and quasi-randomised trials.

DATA COLLECTION AND ANALYSIS

Four review authors independently, and in pairs, screened the references identified in the literature searches and extracted the data. Our primary outcomes were all-cause mortality, the proportion of participants with one or more serious adverse events (SAEs), and quality of life. We analysed all outcomes at maximum follow-up. Only three trials reported the proportion of participants with one or more SAEs as a composite outcome. However, most trials reported on events categorised as SAEs according to the International Conference on Harmonisation Good Clinical Practice (ICH-GCP) criteria. We, therefore, conducted two analyses of the effect of higher versus lower oxygenation strategies using 1) the single SAE with the highest reported proportion in each trial, and 2) the cumulated proportion of participants with an SAE in each trial. Two trials reported on quality of life. Secondary outcomes were lung injury, myocardial infarction, stroke, and sepsis. No trial reported on lung injury as a composite outcome, but four trials reported on the occurrence of acute respiratory distress syndrome (ARDS) and five on pneumonia. We, therefore, conducted two analyses of the effect of higher versus lower oxygenation strategies using 1) the single lung injury event with the highest reported proportion in each trial, and 2) the cumulated proportion of participants with ARDS or pneumonia in each trial. We assessed the risk of systematic errors by evaluating the risk of bias in the included trials using the Risk of Bias 2 tool. We used the GRADEpro tool to assess the overall certainty of the evidence. We also evaluated the risk of publication bias for outcomes reported by 10b or more trials.

MAIN RESULTS

We included 19 RCTs (10,385 participants), of which 17 reported relevant outcomes for this review (10,248 participants). For all-cause mortality, 10 trials were judged to be at overall low risk of bias, and six at overall high risk of bias. For the reported SAEs, 10 trials were judged to be at overall low risk of bias, and seven at overall high risk of bias. Two trials reported on quality of life, of which one was judged to be at overall low risk of bias and one at high risk of bias for this outcome. Meta-analysis of all trials, regardless of risk of bias, indicated no significant difference from higher or lower oxygenation strategies at maximum follow-up with regard to mortality (risk ratio (RR) 1.01, 95% confidence interval (C)I 0.96 to 1.06; I2 = 14%; 16 trials; 9408 participants; very low-certainty evidence); occurrence of SAEs: the highest proportion of any specific SAE in each trial RR 1.01 (95% CI 0.96 to 1.06; I2 = 36%; 9466 participants; 17 trials; very low-certainty evidence), or quality of life (mean difference (MD) 0.5 points in participants assigned to higher oxygenation strategies (95% CI -2.75 to 1.75; I2 = 34%, 1649 participants; 2 trials; very low-certainty evidence)). Meta-analysis of the cumulated number of SAEs suggested benefit of a lower oxygenation strategy (RR 1.04 (95% CI 1.02 to 1.07; I2 = 74%; 9489 participants; 17 trials; very low certainty evidence)). However, trial sequential analyses, with correction for sparse data and repetitive testing, could reject a relative risk increase or reduction of 10% for mortality and the highest proportion of SAEs, and 20% for both the cumulated number of SAEs and quality of life. Given the very low-certainty of evidence, it is necessary to interpret these findings with caution. Meta-analysis of all trials indicated no statistically significant evidence of a difference between higher or lower oxygenation strategies on the occurrence of lung injuries at maximum follow-up (the highest reported proportion of lung injury RR 1.08, 95% CI 0.85 to 1.38; I2 = 0%; 2048 participants; 8 trials; very low-certainty evidence). Meta-analysis of all trials indicated harm from higher oxygenation strategies as compared with lower on the occurrence of sepsis at maximum follow-up (RR 1.85, 95% CI 1.17 to 2.93; I2 = 0%; 752 participants; 3 trials; very low-certainty evidence). Meta-analysis indicated no differences regarding the occurrences of myocardial infarction or stroke.

AUTHORS' CONCLUSIONS

In adult ICU patients, it is still not possible to draw clear conclusions about the effects of higher versus lower oxygenation strategies on all-cause mortality, SAEs, quality of life, lung injuries, myocardial infarction, stroke, and sepsis at maximum follow-up. This is due to low or very low-certainty evidence.

Impact of early screening echocardiography and targeted PDA treatment on neonatal outcomes in "22-23" week and "24-26" infants

The hemodynamically significant patent ductus arteriosus (hsPDA) is a controversial topic in neonatology, particularly among neonates at the earliest gestational ages of 22+0-23+6 weeks. There is little, to no data on the natural history or impact of the PDA in extremely preterm babies. In addition, these high-risk patients have typically been excluded from randomized clinical trials of PDA treatment. In this work, we present the impact of early hemodynamic screening (HS) of a cohort of patients born 22+0-23+6 weeks gestation who either were diagnosed with hsPDA or died in the first postnatal week as compared to a historical control (HC) cohort. We also report a comparator population of 24+0-26+6 weeks gestation. All patients in the HS epoch were evaluated between 12-18h postnatal age and treated based on disease physiology whereas the HC patients underwent echocardiography at the discretion of the clinical team. We demonstrate a two-fold reduction in the composite primary outcome of death prior to 36 weeks or severe BPD and report a lower incidence of severe intraventricular hemorrhage (n=5, 7% vs n=27, 27%), necrotizing enterocolitis (n=1, 1% vs n=11, 11%) and first-week vasopressor use (n=7, 11% vs n=40, 39%) in the HS cohort. HS was also associated with an increase in survival free of severe morbidity from the already high rate of 50% to 73% among neonates <24 weeks gestation. We present a biophysiological rationale behind the potential modulator role of hsPDA on these outcomes and review the physiology relevant to neonates born at these extremely preterm gestations. These data highlight the need for further interrogation of the biological impact of hsPDA and impact of early echocardiography directed therapy in infants born less than 24 weeks gestation.

Feasibility of Nonintubated Anesthesia for Lumboperitoneal Shunt Implantation

Lumboperitoneal shunt (LPS) implantation is a cerebrospinal fluid diversion therapy for the communicating type of normal-pressure hydrocephalus (NPH); NPH mainly affects older adults. However, endotracheal intubation for mechanical ventilation with muscle relaxant increases perioperative and postoperative risks for this population. Based on knowledge from nonintubated thoracoscopic surgery, which has been widely performed in recent years, we describe a novel application of nonintubated anesthesia for LPS implantation in five patients. Anesthesia without muscle relaxants, with a laryngeal mask in one patient and a high-flow nasal cannula in four patients, was used to maintain spontaneous breathing during the surgery. The mean anesthesia time was 103.8 min, and the mean operative duration was 55.8 min. All patients recovered from anesthesia uneventfully. In our experience, nonintubated LPS surgery appears to be a promising and safe surgical technique for appropriately selected patients with NPH.

Non-intubated Thoracic Surgery: Wedge Resections for Peripheral Pulmonary Nodules

The feasibility of performing pulmonary resections of peripheral lung nodules has been one of the main objectives of non-intubated thoracic surgery. The aim was to obtain histological characterization and extend a radical intended treatment to oncological patients unfit for general anesthesia or anatomic pulmonary resections. There is mounting evidence for the role of wedge resection in early-stage lung cancer treatment, especially for frail patients unfit for general anesthesia and anatomic resections with nodules, demonstrating a non-aggressive biological behavior. General anesthesia with single lung ventilation has been associated with a higher risk of ventilator-induced barotrauma and volotrauma as well as atelectasis in both the dependent and non-dependent lungs. Nonetheless, general anesthesia has been shown to impair the host immune system, eventually favoring both tumoral relapses and post-operative complications. Thus, non-intubated wedge resection seems to definitely balance tolerability with oncological radicality in highly selected patients. Nonetheless, differently from other non-surgical techniques, non-intubated wedge resection allows for histological characterization and possible oncological targeted treatment. For these reasons, non-intubated wedge resection is a fundamental skill in the core training of a thoracic surgeon. Main indications, surgical tips, and post-operative management strategies are hereafter presented. Non-intubated wedge resection is one of the new frontiers in minimal invasive management of patients with lung cancer and may become a standard in the armamentarium of a thoracic surgeon. Appropriate patient selection and VATS expertise are crucial to obtaining good results.

Ventilation-Induced Lung Injury (VILI) in Neonates: Evidence-Based Concepts and Lung-Protective Strategies

Supportive care with mechanical ventilation continues to be an essential strategy for managing severe neonatal respiratory failure; however, it is well known to cause and accentuate neonatal lung injury. The pathogenesis of ventilator-induced lung injury (VILI) is multifactorial and complex, resulting predominantly from interactions between ventilator-related factors and patient-related factors. Importantly, VILI is a significant risk factor for developing bronchopulmonary dysplasia (BPD), the most common chronic respiratory morbidity of preterm infants that lacks specific therapies, causes life-long morbidities, and imposes psychosocial and economic burdens. Studies of older children and adults suggest that understanding how and why VILI occurs is essential to developing strategies for mitigating VILI and its consequences. This article reviews the preclinical and clinical evidence on the pathogenesis and pathophysiology of VILI in neonates. We also highlight the evidence behind various lung-protective strategies to guide clinicians in preventing and attenuating VILI and, by extension, BPD in neonates. Further, we provide a snapshot of future directions that may help minimize neonatal VILI.

Effect of ulinastatin on the inflammatory response after video-assisted thoracic lobectomy in patients with lung cancer: a randomized controlled study

Background:

The first-line treatment for lung cancer is surgical resection, and one-lung ventilation (OLV) is the most basic anesthetic management method in lung surgery. During OLV, inflammatory cytokines are released in response to the lung tissue damage and promote local and contralateral lung damage through the systemic circulation. We designed a randomized, prospective study to evaluate the effect of the urinary trypsin inhibitor (UTI) ulinastatin on the inflammatory response after video-assisted thoracic lobectomy in patients with lung cancer.

Methods:

Adult patients aged 19 to 70 years, who were scheduled for video-assisted thoracic lobectomy surgery to treat lung cancer between May 2020 and August 2020, were enrolled in this randomized, prospective study. UTI (300,000 units) mixed with 100 mL of normal saline in the ulinastatin group and 100 mL of normal saline in the control group was administered over 1 h after inducing anesthesia.

Results:

The baseline (T0) interferon-γ (IFN-γ)/interleukin-4 (IL-4) ratio was not different between the groups (6941.3 ± 2778.7 vs. 6954.3 ± 2752.4 pg/mL, respectively; P > 0.05). The IFN-γ/IL-4 ratio was significantly higher in ulinastatin group at 30 min after entering the recovery room than control group (20,148.2 ± 5054.3 vs. 6674.0 ± 2963.6, respectively; adjusted P < 0.017).

Conclusion:

Administering UTI attenuated the anti-inflammatory response, in terms of INF-γ expression and the IFN-γ/IL-4 ratio, after video-assisted thoracic surgery in lung cancer patients.

Trial registration:

Clinical Research Information Service of Korea National Institute of Health (CRIS), KCT0005533.

Comparison of the effect of ultrasound-guided thoracic paravertebral nerve block and intercostal nerve block for video-assisted thoracic surgery under spontaneous-ventilating anesthesia

OBJECTIVE

The aim of the current study was to compare the efficacy of two different techniques for blocking chest nerves during video-assisted thoracic surgery (VATS) under spontaneous-ventilating anesthesia.

METHODS

One hundred patients were recruited in this study and divided into two groups. The first, P group, underwent the TPVB approach; the second, I group, underwent the ICNB approach. Then, the rate of clinical efficacy, duration of the block procedure, and its complications were recorded for comparison of the effect of the two approaches.

RESULTS

No difference was found in the clinical effect of chest nerve blocks between the two groups. Two patients in the ICNB group were converted to general anesthesia due to severe mediastinal flutter (grade three). The number of patients who had grade one mediastinal flutter in the TPVB group was significantly higher than in the ICNB group. Vascular puncture was detected in four patients in the ICNB group and in one patient in the TPVB group. No other complications were observed.

CONCLUSIONS

No difference was found regarding the clinical efficacy in the two groups. However, ultrasound-guided TPVB was superior to ultrasound-guided ICBN during VATS for pulmonary lobectomy under spontaneous-ventilating anesthesia. Additionally, vascular puncture should receive more attention.

Higher versus lower fraction of inspired oxygen or targets of arterial oxygenation for adults admitted to the intensive care unit

BACKGROUND

The mainstay treatment for hypoxaemia is oxygen therapy, which is given to the vast majority of adults admitted to the intensive care unit (ICU). The practice of oxygen administration has been liberal, which may result in hyperoxaemia. Some studies have indicated an association between hyperoxaemia and mortality, whilst other studies have not. The ideal target for supplemental oxygen for adults admitted to the ICU is uncertain. Despite a lack of robust evidence of effectiveness, oxygen administration is widely recommended in international clinical practice guidelines. The potential benefit of supplemental oxygen must be weighed against the potentially harmful effects of hyperoxaemia.

OBJECTIVES

To assess the benefits and harms of higher versus lower fraction of inspired oxygen or targets of arterial oxygenation for adults admitted to the ICU.

SEARCH METHODS

We identified trials through electronic searches of CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, BIOSIS Previews, CINAHL, and LILACS. We searched for ongoing or unpublished trials in clinical trials registers. We also scanned the reference lists of included studies. We ran the searches in December 2018.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared higher versus lower fraction of inspired oxygen or targets of arterial oxygenation for adults admitted to the ICU. We included trials irrespective of publication type, publication status, and language. We included trials with a difference between the intervention and control groups of a minimum 1 kPa in partial pressure of arterial oxygen (PaO2), minimum 10% in fraction of inspired oxygen (FiO2), or minimum 2% in arterial oxygen saturation of haemoglobin/non-invasive peripheral oxygen saturation (SaO2/SpO2). We excluded trials randomizing participants to hypoxaemia (FiO2 below 0.21, SaO2/SpO2 below 80%, and PaO2 below 6 kPa) and to hyperbaric oxygen.

DATA COLLECTION AND ANALYSIS

Three review authors independently, and in pairs, screened the references retrieved in the literature searches and extracted data. Our primary outcomes were all-cause mortality, the proportion of participants with one or more serious adverse events, and quality of life. None of the trials reported the proportion of participants with one or more serious adverse events according to the International Conference on Harmonisation Good Clinical Practice (ICH-GCP) criteria. Nonetheless, most trials reported several serious adverse events. We therefore included an analysis of the effect of higher versus lower fraction of inspired oxygen, or targets using the highest reported proportion of participants with a serious adverse event in each trial. Our secondary outcomes were lung injury, acute myocardial infarction, stroke, and sepsis. None of the trials reported on lung injury as a composite outcome, however some trials reported on acute respiratory distress syndrome (ARDS) and pneumonia. We included an analysis of the effect of higher versus lower fraction of inspired oxygen or targets using the highest reported proportion of participants with ARDS or pneumonia in each trial. To assess the risk of systematic errors, we evaluated the risk of bias of the included trials. We used GRADE to assess the overall certainty of the evidence.

MAIN RESULTS

We included 10 RCTs (1458 participants), seven of which reported relevant outcomes for this review (1285 participants). All included trials had an overall high risk of bias, whilst two trials had a low risk of bias for all domains except blinding of participants and personnel. Meta-analysis indicated harm from higher fraction of inspired oxygen or targets as compared with lower fraction or targets of arterial oxygenation regarding mortality at the time point closest to three months (risk ratio (RR) 1.18, 95% confidence interval (CI) 1.01 to 1.37; I2 = 0%; 4 trials; 1135 participants; very low-certainty evidence). Meta-analysis indicated harm from higher fraction of inspired oxygen or targets as compared with lower fraction or targets of arterial oxygenation regarding serious adverse events at the time point closest to three months (estimated highest proportion of specific serious adverse events in each trial RR 1.13, 95% CI 1.04 to 1.23; I2 = 0%; 1234 participants; 6 trials; very low-certainty evidence). These findings should be interpreted with caution given that they are based on very low-certainty evidence. None of the included trials reported any data on quality of life at any time point. Meta-analysis indicated no evidence of a difference between higher fraction of inspired oxygen or targets as compared with lower fraction or targets of arterial oxygenation on lung injury at the time point closest to three months (estimated highest reported proportion of lung injury RR 1.03, 95% CI 0.78 to 1.36; I2 = 0%; 1167 participants; 5 trials; very low-certainty evidence). None of the included trials reported any data on acute myocardial infarction or stroke, and only one trial reported data on the effects on sepsis.

AUTHORS' CONCLUSIONS

We are very uncertain about the effects of higher versus lower fraction of inspired oxygen or targets of arterial oxygenation for adults admitted to the ICU on all-cause mortality, serious adverse events, and lung injuries at the time point closest to three months due to very low-certainty evidence. Our results indicate that oxygen supplementation with higher versus lower fractions or oxygenation targets may increase mortality. None of the trials reported the proportion of participants with one or more serious adverse events according to the ICH-GCP criteria, however we found that the trials reported an increase in the number of serious adverse events with higher fractions or oxygenation targets. The effects on quality of life, acute myocardial infarction, stroke, and sepsis are unknown due to insufficient data.

Non-invasive ventilation during surgery under neuraxial anaesthesia: a pathophysiological perspective on application and benefits and a systematic literature review

Unlike general anaesthesia, neuraxial anaesthesia (NA) reduces the burden and risk of respiratory adverse events in the post-operative period. However, both patients affected by chronic obstructive pulmonary disease (COPD) and chest wall disorders and/or neuromuscular diseases may experience the development or the worsening of respiratory failure, even during surgery performed under NA; this latter negatively affects the function of accessory respiratory muscles, resulting in a blunted central response to hypercapnia and possibly in an exacerbation of cardiac dysfunction (NA-induced relative hypovolemia). According to European Respiratory Society (ERS) and American Thoracic Society (ATS) guidelines, non-invasive ventilation (NIV) is effective in the post-operative period for the treatment of both impaired pulmonary gas exchange and ventilation, while the intra-operative use of NIV in association with NA is just anecdotally reported in the literature. Whilst NIV does not assure a protected patent airway and requires the patient's cooperation, it is a handy tool during surgery under NA: NIV is reported to be successful for treatment of acute respiratory failure; it may be delivered through the patient's home ventilator, may reverse hypoventilation induced by sedatives or inadvertent spread of anaesthetic up to cervical dermatomes, and allow the avoidance of intubation in patients affected by chronic respiratory failure, prolonging the time of non-invasiveness of respiratory support (i.e., neuromuscular patients needing surgery). All these advantages could make NIV preferable to oxygen in carefully selected patients.

Nonintubated Uniportal Video-Assisted Thoracoscopic Surgery: A Single-Center Experience

Background

We report our surgical technique for nonintubated uniportal video-assisted thoracoscopic surgery (VATS) pulmonary resection and early postoperative outcomes at a single center.

Methods

Between January and July 2017, 40 consecutive patients underwent nonintubated uniportal VATS pulmonary resection. Multilevel intercostal nerve block was performed using local anesthesia in all patients, and an intrathoracic vagal blockade was performed in 35 patients (87.5%).

Results

Twenty-nine procedures (72.5%) were performed in patients with lung cancer (21 lobectomies, 6 segmentectomies, and 2 wedge resections), and 11 (27.5%) in patients with pulmonary metastases, benign lung disease, or pleural disease. The mean anesthesia time was 166.8 minutes, and the mean operative duration was 125.9 minutes. The mean postoperative chest tube duration was 3.2 days, and the mean hospital stay was 5.8 days. There were 3 conversions (7.5%) to intubation due to intraoperative hypoxemia and 1 conversion (2.5%) to multiportal VATS due to injury of the segmental artery. There were 7 complications (17.5%), including 3 cases of prolonged air leak, 2 cases of chylothorax, 1 case of pleural effusion, and 1 case of pneumonia. There was no in-hospital mortality.

Conclusion

Nonintubated uniportal VATS appears to be a feasible and valid surgical option, depending on the surgeon’s experience, for appropriately selected patients.

Non-intubated thoracoscopic surgery: initial experience at a single center

Background

Non-intubated thoracoscopic surgery is an evolving form of minimally-invasive thoracic surgery. We commenced performing non-intubated thoracoscopic surgery at our center in August 2016. We would like to report our initial experience, over a period of 1 year, with this procedure.

Methods

From August 2016 to August 2017, non-intubated thoracoscopic surgery was performed in a series of consecutive patients who underwent thoracoscopic surgery in those who did not meet any of the following exclusion criteria: body mass index (BMI) >30, expected difficult airway, expected extensive pleural adhesion, severe cardiopulmonary dysfunction, persistent cough or excessive airway secretion, high risk of gastric reflux, and underlying neurological disorder.

Results

A total of 115 consecutive patients underwent non-intubated thoracoscopic surgery. Of these, 83 (72.2%) of patients had lung cancers that had undergone pulmonary resection and the other 32 (27.8%) patients were diagnosed with pulmonary metastasis, benign lung diseases, thymic tumor or other conditions. The mean time of anesthesia was 172.4 min and time of operation was 130 min. The mean postoperative chest tube duration was 3.9 days and time of hospital stay was 6.0 days. There were 9 conversions (7.8%) to intubation, due to increased respiratory movement with intraoperative hypoxemia or severe pleural adhesion. There were 16 complications (13.9%) following surgery, but all of these were successfully managed during the period of hospital stay. There was no postoperative mortality. In multivariate analysis, old age and high BMI were significant risk factors for conversion to intubation (hazard ratio =1.122, P=0.038; hazard ratio =1.408, P=0.042, respectively).

Conclusions

Non-intubated thoracoscopic surgery can safely be performed in selected patients.

Revisiting high-frequency oscillatory ventilation in vitro and in silico in neonatal conductive airways

BACKGROUND

High frequency oscillatory ventilation is often used for lung support in premature neonates suffering from respiratory distress syndrome. Despite its broad use in neonatal intensive care units, there are to date no accepted protocols for the choice of appropriate ventilation parameter settings. In this context, the underlying mass transport mechanisms are still not fully understood.

METHODS

We revisit the question of flow phenomena under conventional mechanical ventilation and high frequency oscillatory ventilation in an anatomically-inspired model of neonatal conductive airways spanning the first few airway generations. We first perform at true scale in vitro particle image velocimetry measurements of respiratory flow patterns. Next, we explore in silico convective mass transport in computational fluid dynamics simulations by implementing Lagrangian tracking of tracer boli, where the ventilatory flow rate is fixed.

FINDINGS

Particle image velocimetry measurements at eight representative phase angles of a breathing cycle reveal similar flow patterns at peak velocity and during deceleration phases for conventional mechanical ventilation and high frequency oscillatory ventilation. Characteristic differences occur during the acceleration and flow reversal phases. Net displacements of the tracer particles rapidly reach asymptotic behaviour over cumulative breathing cycles and suggest a linear relation between tidal volume and convective mass transport.

INTERPRETATION

The linear relation observed suggests that differences in flow characteristics between conventional mechanical ventilation and high frequency oscillatory ventilation conditions do not substantially influence convective mass transport mechanisms. Lower tidal volumes thus cannot be compensated straightforwardly by selecting higher frequencies to maintain similar ventilation efficiencies.

Bronchopulmonary dysplasia: A review of pathogenesis and pathophysiology

Bronchopulmonary dysplasia (BPD) is a chronic lung disease of primarily premature infants that results from an imbalance between lung injury and repair in the developing lung. BPD is the most common respiratory morbidity in preterm infants, which affects nearly 10, 000 neonates each year in the United States. Over the last two decades, the incidence of BPD has largely been unchanged; however, the pathophysiology has changed with the substantial improvement in the respiratory management of extremely low birth weight (ELBW) infants. Here we have attempted to comprehensively review and summarize the current literature on the pathogenesis and pathophysiology of BPD. Our goal is to provide insight to help further progress in preventing and managing severe BPD in the ELBW infants.

The feasibility and safety of thoracoscopic surgery under epidural and/or local anesthesia for spontaneous pneumothorax: a meta-analysis

The aim of this study was to compare thoracoscopic surgery for spontaneous pneumothorax under epidural and/or local anesthesia (ELA) with that under general anesthesia and prove the feasibility and safety of thoracoscopic surgery under ELA for spontaneous pneumothorax. Relevant studies were searched in five databases from their date of publication to June 2016. We collected and analyzed the data concerning operative time, hospital stay, complications, air leak, recurrence and perioperative mortality. A forest plot was performed to compare the differences between the two groups. There were no significant differences between the ELA group and the general anesthesia (GA) group in operative time, hospital stay, complications, air leak or recurrence. There were 6 deaths reported in two studies. However, patients in the ELA group had significantly shorter global operating room time. Our study demonstrated that ELA, in comparison with GA, is feasible and safe for thoracoscopic surgery of spontaneous pneumothorax.

The Outcome of Extracorporeal Life Support After General Thoracic Surgery: Timing of Application

BACKGROUND

Extracorporeal life support (ECLS) is widely used in refractory cardiac or pulmonary failure. Because complications of general thoracic surgery frequently involve the heart or lungs, ECLS can be a useful option. Therefore, we retrospectively reviewed our experience with ECLS after general thoracic surgery.

METHODS

There were 17,185 adult general thoracic surgery procedures between 2005 and 2013 at our institution, including resection of the lung (n = 10,434; 60.7%), esophagus (n = 1,847; 0.7%), and other procedures (n = 4,904; 28.5%). Twenty-nine patients (0.2%) were supported by ECLS postoperatively.

RESULTS

The median age was 64 years (range, 24 to 81). Primary operations were lobectomy (n = 13; 44.8%), pneumonectomy (n = 11; 37.9%), and bilobectomy (n = 5; 17.2%). The initial mode of ECLS was venovenous in 20 patients (69.0%) and venoarterial in 9 patients (31.0%). There were 10 patients (34.5%) who survived to decannulation and 7 patients (24.1%) who survived to discharge. Over the same period, the survival to decannulation rate and survival to discharge rate were 49.5% and 35.0%, respectively, among all ECLS patients (n = 759) at our institution. The hospital mortality of patients with surgery to ECLS time of longer than 2 days was 90.9%. Multivariate analysis revealed that a longer surgery to ECLS time was a risk factor for hospital mortality (odds ratio 1.720, 95% confidence interval: 1.039 to 2.849, p = 0.035).

CONCLUSIONS

ECLS after general thoracic surgery can be a viable rescue therapy option. Late presentation of complications or ECLS for late complications of general thoracic surgery may be predictors of death.

Intraoperative and postoperative risk factors for anastomotic leakage and pneumonia after esophagectomy for cancer

Morbidity and mortality after esophagectomy are often related to anastomotic leakage or pneumonia. This study aimed to assess the relationship of intraoperative and postoperative vital parameters with anastomotic leakage and pneumonia after esophagectomy. Consecutive patients who underwent transthoracic esophagectomy with cervical anastomosis for esophageal cancer from January 2012 to December 2013 were analyzed. Univariable and multivariable logistic regression analyses were used to determine potential associations of hemodynamic and respiratory parameters with anastomotic leakage or pneumonia. From a total of 82 included patients, 19 (23%) developed anastomotic leakage and 31 (38%) experienced pneumonia. The single independent factor associated with an increased risk of anastomotic leakage in multivariable analysis included a lower minimum intraoperative pH (OR 0.85, 95% CI 0.77-0.94). An increased risk of pneumonia was associated with a lower mean arterial pressure (MAP) in the first 12 hours after surgery (OR 0.93, 95% CI 0.86-0.99) and a higher maximum intraoperative pH (OR 1.14, 95% CI 1.02-1.27). Interestingly, no differences were noted for the MAP and inotrope requirement between patients with and without anastomotic leakage. A lower minimum intraoperative pH (below 7.25) is associated with an increased risk of anastomotic leakage after esophagectomy, whereas a lower postoperative average MAP (below 83 mmHg) and a higher intraoperative pH (above 7.34) increase the risk of postoperative pneumonia. These parameters indicate the importance of setting strict perioperative goals to be protected intensively.

The non-intubated anesthesia for airway surgery

Surgical treatment for lung cancer including airway resection following reconstruction is typically performed under general anesthesia with single-lung ventilation because it is necessary to maintain a sufficient working space and to adjust the airway pressure for the leak test. However, non-intubated thoracic surgery has been gradually developed in recent years for thoracoscopic surgery, due to its lower rate of postoperative complications, shorter hospitalization duration, and lower invasiveness than the usual single-lung anesthesia. Initially, only minor thoracoscopic surgery, including wedge resection for pneumothorax and the diagnosis of solitary pulmonary nodules, was performed under waking anesthesia. However, major thoracoscopic surgery, including segmentectomy and lobectomy, has also been performed under these conditions in some institutions due to its advantages with respect to the postoperative recovery and in-operating room time. In addition, non-intubated thoracic surgery has been performed for tracheal resection followed by reconstruction to fully explore the advantages of this surgical modality. In this article, the merits and demerits of non-intubated thoracoscopic surgery and the postoperative complications, perioperative problems and optimum selection criteria for patients for thoracic surgery (mainly airway surgery) are discussed.

The differential effects of inspiratory, expiratory, and combined resistive breathing on healthy lung

Combined resistive breathing (CRB) is the hallmark of obstructive airway disease pathophysiology. We have previously shown that severe inspiratory resistive breathing (IRB) induces acute lung injury in healthy rats. The role of expiratory resistance is unknown. The possibility of a load-dependent type of resistive breathing-induced lung injury also remains elusive. Our aim was to investigate the differential effects of IRB, expiratory resistive breathing (ERB), and CRB on healthy rat lung and establish the lowest loads required to induce injury. Anesthetized tracheostomized rats breathed through a two-way valve. Varying resistances were connected to the inspiratory, expiratory, or both ports, so that the peak inspiratory pressure (IRB) was 20%-40% or peak expiratory (ERB) was 40%-70% of maximum. CRB was assessed in inspiratory/expiratory pressures of 30%/50%, 40%/50%, and 40%/60% of maximum. Quietly breathing animals served as controls. At 6 hours, respiratory system mechanics were measured, and bronchoalveolar lavage was performed for measurement of cell and protein concentration. Lung tissue interleukin-6 and interleukin-1β levels were estimated, and a lung injury histological score was determined. ERB produced significant, load-independent neutrophilia, without mechanical or permeability derangements. IRB 30% was the lowest inspiratory load that provoked lung injury. CRB increased tissue elasticity, bronchoalveolar lavage total cell, macrophage and neutrophil counts, protein and cytokine levels, and lung injury score in a dose-dependent manner. In conclusion, CRB load dependently deranges mechanics, increases permeability, and induces inflammation in healthy rats. ERB is a putative inflammatory stimulus for the lung.

Preventing Ventilator-Associated Lung Injury: A Perioperative Perspective

Introduction

Research into the prevention of ventilator-associated lung injury (VALI) in patients with acute respiratory distress syndrome (ARDS) in the intensive care unit (ICU) has resulted in the development of a number of lung protective strategies, which have become commonplace in the treatment of critically ill patients. An increasing number of studies have applied lung protective ventilation in the operating room to otherwise healthy individuals. We review the history of lung protective strategies in patients with acute respiratory failure and explore their use in patients undergoing mechanical ventilation during general anesthesia. We aim to provide context for a discussion of the benefits and drawbacks of lung protective ventilation, as well as to inform future areas of research.

Methods

We completed a database search and reviewed articles investigating lung protective ventilation in both the ICU and in patients receiving general anesthesia through May 2015.

Results

Lung protective ventilation was associated with improved outcomes in patients with acute respiratory failure in the ICU. Clinical evidence is less clear regarding lung protective ventilation for patients undergoing surgery.

Conclusion

Lung protective ventilation strategies, including low tidal volume ventilation and moderate positive end-expiratory pressure, are well established therapies to minimize lung injury in critically ill patients with and without lung disease, and may provide benefit to patients undergoing general anesthesia.

Primary spontaneous pneumothorax: simultaneous treatment by bilateral non-intubated videothoracoscopy

OBJECTIVES

Through a retrospective study, we assessed the feasibility and safety of simultaneous bilateral thoracoscopic wedge resection of blebs or bullae for the treatment of primary spontaneous pneumothorax (PSP) under thoracic epidural anaesthesia with spontaneous ventilation.

METHODS

This retrospective analysis involved a cohort of 37 consecutive patients undergoing simultaneous bilateral thoracoscopic bullectomy under spontaneous ventilation thoracic epidural anaesthesia (n = 15) or intubated general anaesthesia (n = 22) between July 2011 and September 2015. The perioperative data, short-term outcomes and recurrence rates of the two groups were compared.

RESULTS

The two groups had comparable preoperative demographic profiles. There were no conversions to thoracotomy or intubated single-lung ventilation. The peak end-tidal carbon dioxide in the non-intubated group was significantly higher than that in the intubated group (mean: 48 vs 34 mmHg, P < 0.001). Both groups had comparable surgical duration, blood loss and lowest intraoperative pulse oxygen saturation level. Postoperatively, the two groups had comparable chest tube duration, volume of fluid administration, length of hospital stay and complication rates. No mortality occurred. The total anaesthesia cost in non-intubated group was significantly lower (mean: CNY 4584 vs 5649, P = 0.016). The mean follow-up was 23.6 ± 12.9 months in the non-intubated group and 21.1 ± 13.4 months in the intubated group. Two recurrent pneumothoraxes in 2 patients were observed after surgical procedures for PSP. One recurrence developed in the non-intubated group (7%) and one in the intubated group (5%).

CONCLUSIONS

Simultaneous bilateral non-intubated thoracoscopic bullectomy is not only well tolerated and technically feasible but also a safe alternative for selected patients with simultaneous bilateral PSP or with high risk of contralateral recurrence.

MicroRNA Regulation of Acute Lung Injury and Acute Respiratory Distress Syndrome

The acute respiratory distress syndrome (ARDS), a severe form of acute lung injury (ALI), is a very common condition associated with critically ill patients, which causes substantial morbidity and mortality worldwide. Despite decades of research, effective therapeutic strategies for clinical ALI/ARDS are not available. In recent years, microRNAs (miRNAs), small non-coding molecules have emerged as a major area of biomedical research as they post-transcriptionally regulate gene expression in diverse biological and pathological processes, including ALI/ARDS. In this context, this present review summarizes a large body of evidence implicating miRNAs and their target molecules in ALI/ARDS originating largely from studies using animal and cell culture model systems of ALI/ARDS. We have also focused on the involvement of miRNAs in macrophage polarization, which play a critical role in regulating the pathogenesis of ALI/ARDS. Finally, the possible future directions that might lead to novel therapeutic strategies for the treatment of ALI/ARDS are also reviewed. J. Cell. Physiol. 231: 2097-2106, 2016. © 2016 Wiley Periodicals, Inc.

Alveolar instability (atelectrauma) is not identified by arterial oxygenation predisposing the development of an occult ventilator-induced lung injury

BACKGROUND

Improperly set mechanical ventilation (MV) with normal lungs can advance lung injury and increase the incidence of acute respiratory distress syndrome (ARDS). A key mechanism of ventilator-induced lung injury (VILI) is an alteration in alveolar mechanics including alveolar instability or recruitment/derecruitment (R/D). We hypothesize that R/D cannot be identified by PaO2 (masking occult VILI), and if protective ventilation is not applied, ARDS incidence will increase.

METHODS

Sprague-Dawley rats (n = 8) were anesthetized, surgically instrumented, and placed on MV. A thoracotomy was performed and an in vivo microscope attached to the pleural surface of the lung with baseline dynamic changes in alveolar size during MV recorded. Alveolar instability was induced by intra-tracheal instillation of Tween and alveolar R/D identified as a marked change in alveolar size from inspiration to expiration with increases in positive end-expiratory pressure (PEEP) levels.

RESULTS

Despite maintaining a clinically acceptable PaO2 (55-80 mmHg), the alveoli remained unstable with significant R/D at low PEEP levels. Although PaO2 consistently increased with an increase in PEEP, R/D did not plateau until PEEP was >9 cmH2O.

CONCLUSIONS

PaO2 remained clinically acceptable while alveolar instability persisted at all levels of PEEP (especially PEEP <9 cmH2O). Therefore, PaO2 levels cannot be used reliably to guide protective MV strategies or infer that VILI is not occurring. Using PaO2 to set a PEEP level necessary to stabilize the alveoli could underestimate the potential for VILI. These findings highlight the need for more accurate marker(s) of alveolar stability to guide protective MV necessary to prevent VILI.

Nonintubated anesthesia in thoracic surgery: general issues

Anesthetic management for awake thoracic surgery (ATS) is more difficult than under general anesthesia (GA), being technically extremely challenging for the anesthesiologist. Therefore, thorough preparation and vigilance are paramount for successful patient management. In this review, important considerations of nonintubated anesthesia for thoracic surgery are discussed in view of careful patient selection, anesthetic preparation, potential perioperative difficulties and the management of its complications.

Non-intubated video-assisted thoracoscopic surgery anatomical resections: a new perspective for treatment of lung cancer

The lung isolation under general anaesthesia with double lumen tubes has become an indispensable part of video-assisted thoracoscopic surgery (VATS) for lung cancer. However, with an attempt to avoid the residual effects of muscle relaxants and the systemic complications due to tracheal intubation, anesthesia without tracheal intubation has also been applied in VATS surgeries for lung cancer. Currently, non-intubated anesthesia under spontaneous breathing has been widely applied in VATS, contributing to more stable anesthesia and lower rate of switching to intubated anesthesia. It can be applied in most VATS procedures including anatomical pulmonary lobectomy, anatomical segmentectomy, and radical resection for lung cancer. In the selected lung cancer patients, non-intubated anesthesia under spontaneous breathing makes the VATS procedures safer and more feasible. With an equal chance for surgery as the intubated anesthesia, this technique lowers the incidences of peri-operative complications and speeds up post-operative recovery. As a novel surgical option, the anatomic VATS under non-intubated anesthesia under spontaneous breathing have shown to be promising. Nevertheless, the long-term outcomes require further evaluation in more multi-center prospective clinical trials with larger sample sizes.

Non-intubated anesthesia in thoracic surgery-technical issues

Performing awake thoracic surgery (ATS) is technically more challenging than thoracic surgery under general anesthesia (GA), but it can result in a greater benefit for the patient. Local wound infiltration and lidocaine administration in the pleural space can be considered for ATS. More invasive techniques are local wound infiltration with wound catheter insertion, thoracic wall blocks, selective intercostal nerve blockade, thoracic paravertebral blockade and thoracic epidural analgesia, offering the advantage of a catheter placement which can also be continued for postoperative analgesia.

Nonintubated thoracoscopic pulmonary nodule resection under spontaneous breathing anesthesia with laryngeal mask

OBJECTIVE

During the past 20 years, the use of video-assisted thoracoscopic surgery has increased as an important minimally invasive tool. To further reduce its invasiveness, after a preliminary experience, we decided to use a nonintubated spontaneous breathing general anesthesia, for video-assisted thoracoscopic surgery resection of lung nodule, using a laryngeal mask (LMA). This study aimed to verify the safety and the feasibility of this technique.

METHODS

Twenty consecutive patients who underwent thoracoscopic wedge of lung nodule under spontaneous breathing general anesthesia with LMA are the subjects of this study. Clinical data, American Society of Anesthesiologists status, Adult Comorbidity Evaluation-27 score, and Revised Cardiac Risk Index score were recorded for each patient. General inhalatory anesthesia (sevoflurane) was given in all cases through an LMA, without muscle relaxants, thus allowing spontaneous breathing. All procedures were performed in the lateral decubitus position. The maximum and minimum values of end-tidal carbon dioxide tension and oxygen saturation were recorded during the procedure. The level of technical feasibility was stratified by the operating surgeon according to four levels: excellent, good, satisfactory, and unsatisfactory.

RESULTS

There were 13 men and 7 women (mean age, 57 years). The mean induction anesthesia time was 6 minutes, whereas the mean operative time was 38 minutes. The values of oxygen saturation as well as minimum and maximum end-tidal carbon dioxide tension were 99.1%, 33.6 mm Hg, and 39.1 mm Hg, respectively. No mask displacement occurred. The mean operative time was 38 minutes (range, 25-90 minutes). The level of technical feasibility was defined as excellent in 19 cases and good in 1 case. No mortality occurred. Morbidity consisted of pleural effusion (one case), which was medically resolved. The mean postoperative stay was 3.5 days. Histopathologic results were one squamous cell lung cancer (lung primary), one adenocarcinoma (lung primary), five metastasis from colon cancer, four metastasis from breast cancer, three metastasis from renal cancer, three sarcoidosis, two amartocondroma, and one tuberculosis.

CONCLUSIONS

Our experience suggests that thoracoscopic wedge resection of lung nodule is safe and feasible under spontaneous breathing anesthesia with LMA. This technique permits a confident manipulation of lung parenchyma and a safe stapler positioning, without cough, pain, or panic attack described for awake epidural anesthesia, avoiding the risks related to tracheal intubation and mechanical ventilation.

Advances in ventilator-associated lung injury: prevention is the target

Mechanical ventilation (MV) is the main supportive treatment in respiratory failure due to different etiologies. However, MV might aggravate ventilator-associated lung injury (VALI). Four main mechanisms leading to VALI are: 1) increased stress and strain, induced by high tidal volume (VT); 2) increased shear stress, i.e. opening and closing, of previously atelectatic alveolar units; 3) distribution of perfusion and 4) biotrauma. In severe acute respiratory distress syndrome patients, low VT, higher levels of positive end expiratory pressure, long duration prone position and neuromuscular blockade within the first 48 hours are associated to a better outcome. VALI can also occur by using high VT in previously non injured lungs. We believe that prevention is the target to minimize injurious effects of MV. This review aims to describe pathophysiology of VALI, the possible prevention and treatment as well as monitoring MV to minimize VALI.

A knowledge- and model-based system for automated weaning from mechanical ventilation: technical description and first clinical application

To describe the principles and the first clinical application of a novel prototype automated weaning system called Evita Weaning System (EWS). EWS allows an automated control of all ventilator settings in pressure controlled and pressure support mode with the aim of decreasing the respiratory load of mechanical ventilation. Respiratory load takes inspired fraction of oxygen, positive end-expiratory pressure, pressure amplitude and spontaneous breathing activity into account. Spontaneous breathing activity is assessed by the number of controlled breaths needed to maintain a predefined respiratory rate. EWS was implemented as a knowledge- and model-based system that autonomously and remotely controlled a mechanical ventilator (Evita 4, Dräger Medical, Lübeck, Germany). In a selected case study (n = 19 patients), ventilator settings chosen by the responsible physician were compared with the settings 10 min after the start of EWS and at the end of the study session. Neither unsafe ventilator settings nor failure of the system occurred. All patients were successfully transferred from controlled ventilation to assisted spontaneous breathing in a mean time of 37 ± 17 min (± SD). Early settings applied by the EWS did not significantly differ from the initial settings, except for the fraction of oxygen in inspired gas. During the later course, EWS significantly modified most of the ventilator settings and reduced the imposed respiratory load. A novel prototype automated weaning system was successfully developed. The first clinical application of EWS revealed that its operation was stable, safe ventilator settings were defined and the respiratory load of mechanical ventilation was decreased.

Long-term home noninvasive mechanical ventilation increases systemic inflammatory response in chronic obstructive pulmonary disease: a prospective observational study

BACKGROUND

Long-term home noninvasive mechanical ventilation (NIV) is beneficial in COPD but its impact on inflammation is unknown. We assessed the hypothesis that NIV modulates systemic and pulmonary inflammatory biomarkers in stable COPD.

METHODS

Among 610 patients referred for NIV, we shortlisted those undergoing NIV versus oxygen therapy alone, excluding subjects with comorbidities or non-COPD conditions. Sputum and blood samples were collected after 3 months of clinical stability and analyzed for levels of human neutrophil peptides (HNP), interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-alpha). Patients underwent a two-year follow-up. Unadjusted, propensity-matched, and pH-stratified analyses were performed.

RESULTS

Ninety-three patients were included (48 NIV, 45 oxygen), with analogous baseline features. Sputum analysis showed similar HNP, IL-6, IL-10, and TNF-alpha levels (P > 0.5). Conversely, NIV group exhibited higher HNP and IL-6 systemic levels (P < 0.001) and lower IL-10 concentrations (P < 0.001). Subjects undergoing NIV had a significant reduction of rehospitalizations during follow-up compared to oxygen group (P = 0.005). These findings were confirmed after propensity matching and pH stratification.

CONCLUSIONS

These findings challenge prior paradigms based on the assumption that pulmonary inflammation is per se detrimental. NIV beneficial impact on lung mechanics may overcome the potential unfavorable effects of an increased inflammatory state.

Nonintubated Video-Assisted Thoracoscopic Surgery Under Epidural Anesthesia Compared With Conventional Anesthetic Option

Objective. The purposes of this study were to evaluate the feasibility, safety, and advantages of nonintubated video-assisted thoracoscopic surgery (VATS) under epidural anesthesia, by comparing with the performance of conventional approaches. Patients and methods. A total of 354 patients (245 men and 109 women) were recruited in this study. The surgical procedures included bullae resection, pulmonary wedge resection, and lobectomy. The anesthetic technique (epidural vs general) was selected randomly. Patients who underwent nonintubated VATS under epidural anesthesia comprised the intervention group, and patients who received VATS under general anesthesia with double lumen tube comprised the control group. Results. In total, 167 patients were included in the intervention group, and 180 patients were included in the control group. The 2 treatment groups of bullae resection showed significant differences in postoperative fasting time, duration of postoperative antibiotic use depending on the time when the white blood cells decreased to normal levels, and duration of postoperative hospital stay ( P < .05). Nonintubated VATS is associated with a decreased level of inflammatory cytokines ( P < .05). Conclusion. VATS under anesthesia with nontracheal intubation is safe and feasible, and has demonstrated advantages, including shorter postoperative fasting time, shorter duration of antibiotic use, and shorter hospital stay, compared with VATS under general anesthesia with double lumen tube.

Effect of invariant natural killer T cells with IL-5 and activated IL-6 receptor in ventilator-associated lung injury in mice

Mechanical ventilation (MV) is well known to potentially cause ventilator-associated lung injury (VALI). It has also been reported recently that activation of invariant natural killer T (iNKT) cells is involved in the onset/progression of airway inflammation. We analyzed the roles of inflammatory cells, including iNKT cells, and cytokines/chemokines in a mouse model of VALI. C57BL/6 and Vα14(+)NKT cell-deficient (Jα18KO) female mice were subjected to MV for 5 hours. The MV induced lung injury in the mice, with severe histological abnormalities, elevation in the percentages of neutrophils in the bronchoalveolar lavage fluid (BALF), and increase in the number of iNKT cells in the lung. Jα18KO mice subjected to MV for 5 hours also showed lung injury, with decrease of the PaO2/FiO2 ratio (P/F ratio) and elevation of the levels of total protein, IL-5, IL-6, IL-12p40, and keratinocyte-derived cytokine (KC) in the BALF. Intranasal administration of anti-IL-5 monoclonal antibody (mAb) or anti-IL-6 receptor (IL-6R) mAb into the Jα18KO mice prior to the start of MV resulted in significant improvement in the blood oxygenation. In addition, the anti-IL-5 mAb administration was associated with a decrease in the levels of IL-5, IL-9, and IL-6R in the BALF, and anti-IL-6R mAb administration suppressed the mRNA expressions of IL-5, IL-6, IL-6R, and KC. These results suggest that iNKT cells may play a role in attenuating the inflammatory caused by ventilation through IL-5 and IL-6R.

Lung re-expansion following one-lung ventilation induces neutrophil cytoskeletal rearrangements in rats

PURPOSE

To investigate the morphological and functional behavior of neutrophils during and after one-lung ventilation (OLV).

METHODS

We utilized an OLV rat model system and performed 3 hours of OLV followed by either re-expansion (RE) and 30 minutes of two-lung ventilation (TLV) (RE group), only two-lung ventilation (TLV group), or only OLV (OLV group). Cytoskeletal rearrangements of circulating neutrophils were assessed by determining the localization of filamentous actin (F-actin). In addition, the number of sequestered neutrophils in the lung capillary and the cytokine-induced neutrophil chemoattractant 1 (CINC-1) levels in the plasma were determined.

RESULTS

The F-actin rimmed neutrophils in the RE group increased after RE, but did not increase in the other groups. In the RE group, the sequestered neutrophils in the ventilated lung were significantly more numerous, and the plasma CINC-1 levels were significantly higher than in the other groups.

CONCLUSIONS

Lung RE following OLV induces cytoskeletal rearrangements in circulating neutrophils and would thereby promote their sequestration in the lung capillaries. The plasma CINC-1 elevation after RE can be involved in neutrophil recruitment.