Worsening Gas Exchange Research Articles

Tenecteplase: A Review of Its Pharmacology and Uses.

Tenecteplase: A Review of Its Pharmacology and Uses.

Effect of expiratory flow limitation on ventilation/perfusion mismatch and perioperative lung function during pneumoperitoneum and Trendelenburg position.

Laparoscopic surgery and Trendelenburg position may affect the respiratory function and alter the gas exchange. Further the reduction of the lung volumes may contribute to the development of expiratory flow limitation (EFL). The latter is associated with an increased risk of postoperative pulmonary complications. Our aim was to investigate the incidence of EFL and to evaluate its effect on pulmonary function and intraoperative V/Q mismatch. This is a prospective study on patients undergoing elective laparoscopic gynecological surgery. We evaluated respiratory mechanics, V/Q mismatch and presence of EFL after anesthesia induction, during pneumoperitoneum and Trendelenburg position and at the end of surgery. Intraoperative gas exchange and hemodynamic were also recorded. Clinical data were collected until seven days after surgery to evaluate the onset of pulmonary postoperative complications (PPCs). Among the 66 patients enrolled, 25/66 (38%) exhibited EFL during surgery, of whom 10/66 (15%) after anesthesia induction, and the remaining 15 patients after pneumoperitoneum and Trendelenburg position. Median PEEP able to reverse flow limitation was 7 [7-10] cmH2O after anesthesia induction and 9 [8-15] cmH2O after pneumoperitoneum and Trendelenburg position. Patients with EFL had significantly higher shunt (17 [2-25] vs. 9 [1-19]; P=0.05), low V̇/Q̇ (27 [20-70] vs. 15 [10-22]; P=0.05) and high V̇/Q̇ (10 [7-14] vs. 6 [4-7]; P=0.024). At the end of surgery, only high V/Q was significantly higher in EFL patients. Further, they exhibited higher incidence of postoperative pulmonary complication (48% (12/25) vs. 15% (6/41), P=0.005), hypoxemia and hypercapnia (80% [20/25] vs. 32% [13/41]; P<0.001). Expiratory flow limitation is a common phenomenon during gynecological laparoscopic surgery associated with worsen gas exchange, increased V/Q mismatch and altered lung mechanics. Our study showed that patients experiencing EFL during surgery showed a higher risk for PPCs.

Phase angle in assessment and monitoring treatment of individuals with respiratory disease.

Phase angle (PhA) represents a raw variable measured with bioelectrical impedance analysis (BIA) that is used to assess malnutrition in many diseases, including respiratory diseases, mainly chronic obstructive pulmonary disease (COPD). COPD patients with reduced PhA are older, more hypoxic and hypercapnic; patients with more severe COPD have reduced cell mass, evident skeletal muscle depletion, and worsening gas exchange. Malnourished patients with stable COPD in long-term oxygen therapy (LTOT) have more intense dyspnea at rest, greater weight loss over the past 12 months, and more exacerbations per year. Multiple regression analysis highlighted the significance of PhA° in the estimation of muscle strength: hand grip strength (HGS) and in that of respiratory muscles: maximal inspiratory pressure / max. expiratory pressure ratio (MIP/MEP). Furthermore, the relationship between PhA° and all-cause mortality in COPD patients was confirmed with the Cox regression model, Kaplan-Meier test, and log-rank tests. The role of malnutrition in idiopathic pulmonary fibrosis (IPF) is confirmed by the PhA° measurements which, regardless of body weight, is associated with the reduction in muscle mass of these patients, reduces their strength and exercise capacity, and greatly influences the prognosis. In conclusion PhA is a novel biomarker of morbidity and mortality in patients with severe respiratory diseases.

Clinical Evaluation and Management of Overlap Syndrome (OS) and Obesity Hypoventilation Syndrome (OHS).

Background and Aim: Sleep-disordered breathing (SDB) is an extremely common disorder with a high impact on morbidity and mortality. The purpose of this study was to compare overlap syndrome (OS) and obesity hypoventilation syndrome (OHS) and to highlight and understand the differences between them. Material and Methods: The study was conducted retrospectively on 132 subjects selected by consecutive sampling from those attending our unit for suspected SDB. After clinical evaluation as well as functional and sleep investigations, the population was divided according to diagnosis in OS and OHS; then, the clinical parameters of two groups were compared with different statistical analysis. Results: The subjects with OHS were younger and reported higher rated daytime sleepiness (p = 0.005). In addition, they presented more nocturnal respiratory events (apnea-hypopnea index (AHI) 63.61 ± 22.79 events·h-1 vs. AHIOS 42.21 ± 22.91 events·h-1, p &lt; 0.0001) at the sleep investigation as worse gas exchange during sleep leading to a higher percentage of nocturnal hypoxemia (p &lt; 0.0001). In contrast, subjects with OS had more an impaired respiratory function. With regard to night-time ventilatory therapy, more subjects with OS were effectively treated with continuous positive airway pressure (CPAP) (p = 0.011), while more OHS were treated with auto-adjusting PAP (APAP) (14% vs. 1%, p = 0.008). Conclusions: The present study tried to establish a framework for OS and OHS because proper management of the two disorders would reduce their burden on healthcare.

DELAYED ASPIRATION THROMBECTOMY OF SADDLE PULMONARY EMBOLISM IN A HEMODYNAMICALLY STABLE PATIENT

DELAYED ASPIRATION THROMBECTOMY OF SADDLE PULMONARY EMBOLISM IN A HEMODYNAMICALLY STABLE PATIENT

CASE REPORT OF RAPIDLY DECOMPENSATING PRIMARY PULMONARY CARCINOSARCOMA

CASE REPORT OF RAPIDLY DECOMPENSATING PRIMARY PULMONARY CARCINOSARCOMA

Ventilator-Associated Pneumonia in the Neonatal Intensive Care Unit

See Bonus NeoBriefs videos and downloadable teaching slides Intubated infants in the NICU are at risk of developing ventilator-associated pneumonia (VAP), a common type of health care-associated infection. The Centers for Disease Control and Prevention developed guidelines for diagnosing VAP in patients younger than 1 year, which include worsening gas exchange, radiographic findings, and at least 3 defined clinical signs of pneumonia. VAP in infants is treated with empiric antibiotics selected based on local resistance patterns and individualized patient data. Many NICUs have implemented prevention bundles in an effort to decrease VAP by ensuring the cleanest environment for intubated neonates (hand hygiene, sterile handling of equipment), positioning of infants to prevent gastric reflux, and constantly reevaluating for extubation readiness. Although these prevention bundle elements are intuitive and generally low risk, none are based on strong research support. This article reviews the epidemiology, pathogenesis, diagnosis, treatment, and prevention of VAP in NICU patients, focusing on recent evidence, highlighting areas of emerging research, and identifying persistent knowledge gaps.

Survival of COVID-19 Patients With Respiratory Failure is Related to Temporal Changes in Gas Exchange and Mechanical Ventilation.

Background: Respiratory failure due to coronavirus disease of 2019 (COVID-19) often presents with worsening gas exchange over a period of days. Once patients require mechanical ventilation (MV), the temporal change in gas exchange and its relation to clinical outcome is poorly described. We investigated whether gas exchange over the first 5 days of MV is associated with mortality and ventilator-free days at 28 days in COVID-19. Methods: In a cohort of 294 COVID-19 patients, we used data during the first 5 days of MV to calculate 4 daily respiratory scores: PaO2/FiO2 (P/F), oxygenation index (OI), ventilatory ratio (VR), and Murray lung injury score. The association between these scores at early (days 1-3) and late (days 4-5) time points with mortality was evaluated using logistic regression, adjusted for demographics. Correlation with ventilator-free days was assessed (Spearman rank-order coefficients). Results: Overall mortality was 47.6%. Nonsurvivors were older (P < .0001), more male (P = .029), with more preexisting cardiopulmonary disease compared to survivors. Mean PaO2 and PaCO2 were similar during this timeframe. However, by days 4 to 5 values for all airway pressures and FiO2 had diverged, trending lower in survivors and higher in nonsurvivors. The most substantial between-group difference was the temporal change in OI, improving 15% in survivors and worsening 11% in nonsurvivors (P < .05). The adjusted mortality OR was significant for age (1.819, P = .001), OI at days 4 to 5 (2.26, P = .002), and OI percent change (1.90, P = .02). The number of ventilator-free days correlated significantly with late VR (−0.166, P < .05), early and late OI (−0.216, P < .01; −0.278, P < .01, respectively) and early and late P/F (0.158, P < .05; 0.283, P < .01, respectively). Conclusion: Nonsurvivors of COVID-19 needed increasing intensity of MV to sustain gas exchange over the first 5 days, unlike survivors. Temporal change OI, reflecting both PaO2 and the intensity of MV, is a potential marker of outcome in respiratory failure due to COVID-19.

The Role of High Flow Nasal Cannula in COVID-19 Associated Pneumomediastinum and Pneumothorax.

Background: Pneumomediastinum, subcutaneous emphysema and pneumothorax are not rarely observed during the COVID-19 pandemic. Such complications can worsen gas exchange and the overall prognosis in critical patients. The aim of this study is to investigate what predisposing factors are related to pneumomediastinum and pneumothorax in SARS-CoV2-Acute Respiratory Distress Syndrome (ARDS), what symptoms may predict a severe and potentially fatal complication and what therapeutical approach may provide a better outcome. Methods: In this single center cohort study, we recorded data from 45 critically ill COVID-19 patients who developed one or more complicating events among pneumomediastinum, subcutaneous emphysema and pneumothorax. All patients showed ARDS and underwent non-invasive ventilation (NIV) at baseline. Patients with mild to moderate ARDS and pneumomediastinum/pneumothorax (n = 25) received High Flow Nasal Cannula (HFNC), while patients with severe ARDS and pneumomediastinum/pneumothorax underwent HFNC (n = 10) or invasive mechanical ventilation (IMV) (n = 10). Results: Pneumomediastinum/pneumothorax developed in 10.5% of subjects affected by SARS-coV2-ARDS. Dyspnea affected 40% and cough affected 37% of subjects. High resolution computed tomography of the chest showed bilateral diffuse ground glass opacities (GGO) in 100% of subjects. Traction bronchiolectasis, reticulation, crazy paving and distortion were observed in 64%. Furthermore, 36% showed subcutaneous emphysema. Non-severe ARDS cases received HFNC, and 76% patients recovered from pneumomediastinum/pneumothorax over a median follow up of 5 days. Among severe ARDS cases the recovery rate of pneumomediastinum/pneumothorax was 70% with the HFNC approach, and 10% with IMV. Conclusion: HFNC is a safe and effective ventilatory approach for critical COVID-19 and has a positive role in associated complications such as pneumomediastinum and pneumothorax.

Pneumothorax in critically ill patients with COVID-19 infection: Incidence, clinical characteristics and outcomes in a case control multicenter study

BackgroundThe clinical features and outcomes of mechanically ventilated patients with COVID-19 infection who develop a pneumothorax has not been rigorously described or compared to those who do not develop a pneumothorax. PurposeTo determine the incidence, clinical characteristics, and outcomes of critically ill patients with COVID-19 infection who developed pneumothorax. In addition, we compared the clinical characteristics and outcomes of mechanically ventilated patients who developed a pneumothorax with those who did not develop a pneumothorax. MethodsThis study was a multicenter retrospective analysis of all adult critically ill patients with COVID-19 infection who were admitted to intensive care units in 4 tertiary care centers in the United States. ResultsA total of 842 critically ill patients with COVID-19 infection were analyzed, out of which 594 (71%) were mechanically ventilated. The overall incidence of pneumothorax was 85/842 (10%), and 80/594 (13%) in those who were mechanically ventilated. As compared to mechanically ventilated patients in the non-pneumothorax group, mechanically ventilated patients in the pneumothorax group had worse respiratory parameters at the time of intubation (mean PaO2:FiO2 ratio 105 vs 150, P<0.001 and static respiratory system compliance: 30ml/cmH2O vs 39ml/cmH2O, P = 0.01) and significantly higher in-hospital mortality (63% vs 49%, P = 0.04). ConclusionThe overall incidence of pneumothorax in mechanically ventilated patients with COVID-19 infection was 13%. Mechanically ventilated patients with COVID-19 infection who developed pneumothorax had worse gas exchange and respiratory mechanics at the time of intubation and had a higher mortality compared to those who did not develop pneumothorax.

Telomere length dynamics over 10-years and related outcomes in patients with COPD

BackgroundChronic obstructive pulmonary disease (COPD) has been proposed as a disease of accelerated aging. Several cross-sectional studies have related a shorter telomere length (TL), a marker of biological aging, with COPD outcomes. Whether accelerated telomere shortening over time relates to worse outcomes in COPD patients, is not known.MethodsRelative telomere length (T/S) was determined by qPCR in DNA samples from peripheral blood in 263 patients at baseline and up to 10 years post enrolment. Yearly clinical and lung function data of 134 patients with at least two-time measures of T/S over this time were included in the analysis.ResultsAt baseline, T/S inversely correlated with age (r = − 0.236; p < 0.001), but there was no relationship between T/S and clinical and lung function variables (p > 0.05). Over 10 years of observation, there was a median shortening of TL of 183 bp/year for COPD patients. After adjusting for age, gender, active smoking and mean T/S, patients that shortened their telomeres the most over time, had worse gas exchange, more lung hyperinflation and extrapulmonary affection during the follow-up, (PaO2 p < 0.0001; KCO p = 0.042; IC/TLC p < 0.0001; 6MWD p = 0.004 and BODE index p = 0.009). Patients in the lowest tertile of T/S through the follow-up period had an increased risk of death [HR = 5.48, (1.23–24.42) p = 0.026].ConclusionsThis prospective study shows an association between accelerated telomere shortening and progressive worsening of pulmonary gas exchange, lung hyperinflation and extrapulmonary affection in COPD patients. Moreover, persistently shorter telomeres over this observation time increase the risk for all-cause mortality.

Different Clusters in Patients with Chronic Obstructive Pulmonary Disease (COPD): A Two-Center Study in Brazil.

BackgroundChronic obstructive pulmonary disease (COPD) has a functional definition. However, differences in clinical characteristics and systemic manifestations make COPD a heterogeneous disease and some manifestations have been associated with different risks of acute exacerbations, hospitalizations, and death.ObjectiveTherefore, the objective of the study was to evaluate possible clinical clusters in COPD at two study centers in Brazil and identify the associated exacerbation and mortality rate during 1 year of follow-up.MethodsWe included patients with COPD and all underwent an evaluation composed of the Charlson Index, body mass index (BMI), current pharmacological treatment, smoking history (packs-year), history of exacerbations/hospitalizations in the last year, spirometry, six-minute walking test (6MWT), quality of life questionnaires, dyspnea, and hospital anxiety and depression scale. Blood samples were also collected for measurements of C-reactive protein (CRP), blood gases, laboratory analysis, and blood count. For the construction of the clusters, 13 continuous variables of clinical importance were considered: hematocrit, CRP, triglycerides, low density lipoprotein, absolute number of peripheral eosinophils, age, pulse oximetry, BMI, forced expiratory volume in the first second, dyspnea, 6MWD, total score of the Saint George Respiratory Questionnaire and packs-year of smoking. We used the Ward and K-means methods and determined the best silhouette value to identify similarities of individuals within the cluster (cohesion) in relation to the other clusters (separation). The number of clusters was determined by the heterogeneity values of the cluster, which in this case was determined as four clusters.ResultsWe evaluated 301 COPD patients and identified four different groups of COPD patients. The first cluster (203 patients) was characterized by fewer symptoms and lower functional severity of the disease, the second cluster by higher values of peripheral eosinophils, the third cluster by more systemic inflammation and the fourth cluster by greater obstructive severity and worse gas exchange. Cluster 2 had an average of 959±3 peripheral eosinophils, cluster 3 had a higher prevalence of nutritional depletion (46.1%), and cluster 4 had a higher BODE index. Regarding the associated comorbidities, we found that only obstructive sleep apnea syndrome and pulmonary thromboembolism were more prevalent in cluster 4. Almost 50% of all patients presented an exacerbation during 1 year of follow-up. However, it was higher in cluster 4, with 65% of all patients having at least one exacerbation. The mortality rate was statistically higher in cluster 4, with 26.9%, vs 9.6% in cluster 1.ConclusionWe could identify four clinical different clusters in these COPD populations, that were related to different clinical manifestations, comorbidities, exacerbation, and mortality rate. We also identified a specific cluster with higher values of peripheral eosinophils.

Diagnosis of Hepatopulmonary Syndrome in a Large Integrated Health System

Data on the accuracy of the diagnosis of hepatopulmonary syndrome (HPS) in cirrhosis is limited. We evaluated the clinical characteristics of patients with International Classification of Diseases (ICD) codes for hepatopulmonary syndrome (HPS) in a large integrated health system. A retrospective review of encounters was performed of all patients with ICD-9-CM and/or ICD-10-CM diagnosis of cirrhosis and HPS from 2014-2019 in a multi-state health system. Demographics and cardiopulmonary testing closest to the time of HPS diagnosis were recorded. HPS was defined using standard criteria. A total of 42,749 unique individuals with cirrhosis were identified. An ICD diagnosis of HPS was found in 194 patients (0.45%), of which 182 had clinically confirmed cirrhosis. 143 (78.5%) underwent contrast-enhanced transthoracic echocardiography, and 98 (54%) had delayed shunting. Among them, 61 patients had a documented arterial blood gas, with 53 showing abnormal oxygenation (A-a gradient of >15 mm Hg). 12 were excluded due to significant pulmonary function test abnormalities and abnormal oxygenation from other cardiopulmonary diseases. Ultimately, 41 (22.5%) fulfilled the criteria for HPS. When stratifying those with an ICD code diagnosis of HPS into HPS, no HPS and indeterminate HPS groups, based on standard diagnostic criteria for HPS, we found that the confirmed HPS patients had similar complications except for less portopulmonary hypertension, worse gas exchange, less cardiopulmonary disease and were more often diagnosed in transplant centers. The diagnosis of HPS by ICD code is made in an extremely small subset of a sizeable cirrhotic cohort. When made, only a minority of these patients meet diagnostic criteria. Our findings highlight the need for improved education and more effective screening algorithms.

Pathophysiology of worsening lung function in COVID-19

Introduction: The new coronavirus pneumonia (COVID-19) has emerged as the main threats to global health since December 2019. Addressing part of the pulmonary pathophysiology involved in the disease is important to help interested health professionals better understand the different aspects of this complex pathology. Aim: This article aims to present part of the pathophysiological process involved in pulmonary complications associated with Covid-19. Methods: An integrative literature review was carried out, with articles published between 2019 and 2020, in the Google and PubMed databases, using the following search terms: coronavirus, COVID-19, pulmonary complications, pneumonia. Results: 6 articles were included, addressing the proposed theme. Conclusion: The individual's infection with COVID-19 has the potential to cause significant changes in ventilatory capacity, leading to diffuse pulmonary impairment and worsening gas exchange. Further studies are needed to clarify the pathophysiology of this complex disease with a high potential for contagion, morbidity and mortality.Keywords: coronavirus infections, communicable diseases, pneumonia. Â

Clinical decision-making on spinal cord injury-associated pneumonia: a nationwide survey in Germany

Study designSurvey study.ObjectivesSpinal cord injury (SCI)-associated pneumonia (SCI-AP) is associated with poor functional recovery and a major cause of death after SCI. Better tackling SCI-AP requires a common understanding on how SCI-AP is defined. This survey examines clinical algorithms relevant for diagnosis and treatment of SCI-AP.SettingAll departments for SCI-care in Germany.MethodsThe clinical decision-making on SCI-AP and the utility of the Centers for Disease Control and Prevention (CDC) criteria for diagnosis of ‘clinically defined pneumonia’ were assessed by means of a standardized questionnaire including eight case vignettes of suspected SCI-AP. The diagnostic decisions based on the case information were analysed using classification and regression trees (CART).ResultsThe majority of responding departments were aware of the CDC-criteria (88%). In the clinical vignettes, 38–81% of the departments diagnosed SCI-AP in accordance with the CDC-criteria and 7–41% diagnosed SCI-AP in deviation from the CDC-criteria. The diagnostic agreement was not associated with the availability of standard operating procedures for SCI-AP management in the departments. CART analysis identified radiological findings, fever, and worsened gas exchange as most important for the decision on SCI-AP. Frequently requested supplementary diagnostics were microbiological analyses, C-reactive protein, and procalcitonin. For empirical antibiotic therapy, the departments used (acyl-)aminopenicillins/β-lactamase inhibitors, cephalosporins, or combinations of (acyl-)aminopenicillins/β-lactamase inhibitors with fluoroquinolones or carbapenems.ConclusionsThis survey reveals a diagnostic ambiguity regarding SCI-AP despite the awareness of CDC-criteria and established SOPs. Heterogeneous clinical practice is encouraging the development of disease-specific guidelines for diagnosis and management of SCI-AP.

Higher age and obesity limit atelectasis formation during anaesthesia: an analysis of computed tomography data in 243 subjects

BackgroundGeneral anaesthesia is increasingly common in elderly and obese patients. Greater age and body mass index (BMI) worsen gas exchange. We assessed whether this is related to increasing atelectasis during general anaesthesia. MethodsThis primary analysis included pooled data from previously published studies of 243 subjects aged 18–78 yr, with BMI of 18–52 kg m−2. The subjects had no clinical signs of cardiopulmonary disease, and they underwent computed tomography (CT) awake and during anaesthesia before surgery after preoxygenation with an inspired oxygen fraction (FIO2) of >0.8, followed by mechanical ventilation with FIO2 of 0.3 or higher with no PEEP. Atelectasis was assessed by CT. ResultsAtelectasis area of up to 39 cm2 in a transverse scan near the diaphragm was seen in 90% of the subjects during anaesthesia. The log of atelectasis area was related to a quadratic function of (age+age2) with the most atelectasis at ∼50 yr (r2=0.08; P<0.001). Log atelectasis area was also related to a broken-line function of the BMI with the knee at 30 kg m−2 (r2=0.06; P<0.001). Greater atelectasis was seen in the subjects receiving FIO2 of 1.0 than FIO2 of 0.3–0.5 (12.8 vs 8.1 cm2; P<0.001). A multiple regression analysis, including a quadratic function of age, a broken-line function of the BMI, and dichotomised FIO2 (0.3–0.5/1.0) adjusting for ventilatory frequency, strengthened the association (r2=0.23; P<0.001). PaO2 decreased with both age and BMI. ConclusionsAtelectasis during general anaesthesia increased with age up to 50 yr and decreased beyond that. Atelectasis increased with BMI in normal and overweight patients, but showed no further increase in obese subjects (BMI ≥30 kg m−2). Therefore, greater age and obesity appear to limit atelectasis formation during general anaesthesia.

Features of the mechanics of respiration and gas exchange during robot-assisted radical prostatectomy. Review

Introduction. Prostate cancer remains the most common urological malignancy, and robot-assisted radical prostatectomy (RARP) is the most effective treatment option. Special conditions for operation (Trendelenburg position and pneumoperitoneum) increase the airway pressure and reduce functional residual capacity of the lungs. Objectives. Review of risk factors for disorders and various interventions to improve pulmonary function and reduce the adverse physiological effects of RARP under general anesthesia. Materials and methods. This review of literature was conducted using the PubMed search engine in electronic databases Medline, Embase, the Cochrane Library and others up to May 2019. Results. A total of 22 studies were searched, including 9 randomized controlled trials. The factor that could worsen gas exchange during RARP was the body mass index &lt; 30 kg/m2. It is possible to improve gas exchange by means of recruitment maneuvers. Positive end-expiratory pressure of 5–10 cm H2O improves oxygenation but requires alertness in patients with chronic heart failure and chronic obstructive pulmonary disease. Conclusions. The main risk factors for perioperative respiratory and oxygenation disorders in RARP are pneumoperitoneum and steep Trendelenburg position. The effectiveness of ventilation regimes for the prevention of gas exchange disorders has not been proven. Using the recruitment maneuver and increasing the positive end-expiratory pressure does not improve the respiratory function of the lungs. Further studies with a longer follow-up period are needed to determine the clinical efficacy and safety of RARP.

Effects of nitric oxide donor on the lung functions in a saline lavage-induced model of ARDS.

Acute respiratory distress syndrome (ARDS) is characterized by acute hypoxemia, neutrophil-mediated inflammation, and lung edema formation. Whereas lung damage might be alleviated by nitric oxide (NO), goal of this study was to evaluate if intratracheal NO donor S-nitroso-N-acetylpenicillamine (SNAP) can positively influence the lung functions in experimental model of ARDS. New Zealand rabbits with respiratory failure induced by saline lavage (30 ml/kg, 9+/-3 times) were divided into: ARDS group without therapy, ARDS group treated with SNAP (7 mg/kg i.t.), and healthy Control group. During 5 h of ventilation, respiratory parameters (blood gases, ventilatory pressures) were estimated. After anesthetics overdosing, left lung was saline-lavaged and cell count, cell viability and protein content in bronchoalveolar lavage fluid (BALF) were measured. Right lung tissue was used for estimation of wet/dry weight ratio, concentration of NO metabolites, and histomorphological investigation. Repetitive lung lavage induced lung injury, worsened gas exchange, and damaged alveolar-capillary membrane. Administration of SNAP reduced cell count in BALF, lung edema formation, NO metabolites, and histopathological signs of injury, and improved respiratory parameters. Treatment with intratracheal SNAP alleviated lung injury and edema and improved lung functions in a saline-lavaged model of ARDS suggesting a potential of NO donors also for patients with ARDS.

Does jasmonic acid regulate photosynthesis, clastogenecity, and phytochelatins in Brassica juncea L. in response to Pb-subcellular distribution?

The present experiment unravels how exogenous jasmonic acid regulates photosynthesis, clastogenecity, AsA-GSH cycle and phytochelatins in Brassica juncea L. in response to Pb-subcellular distribution. The plants were evaluated for leaf gas exchange parameters, Fv/Fm, lipid peroxidation, leaf epidermal structures and ABA content. Besides lead accumulation in root, shoot and its subcellular distribution pattern, its role as clastogen and/or aneuploidogen via DNA damage, genome size and ploidy variations, AsA-GSH cycle and quantification of PC2 and PC3 were performed as well. Results revealed that Pb inhibited plant growth, disturbed epidermal and guard cells and consequently worsen leaf gas exchange parameters (E, GH2O, A), Fv/Fm and photosynthetic pigments. For clastogenecity, results revealed considerable DNA damage and analysis for genome size showed that differences between unstressed, Pb-stress and JA application were not significant (P≤0.05), however, ploidy ratio analysis proved partial aneuploidogenic role of Pb. The highest Pb exposure affected AsA-GSH cycle negatively but increased PC2 and PC3 contents uniformly in roots and leaves. Surprisingly, exogenous JA inhibits plant growth under non-stress but positively regulates growth, photosynthesis, AsA-GSH cycle, PC2 and PC3 contents and DNA damage but has no significant effect on variations in total genome size and ploidy under Pb-stress.

Ventilator-Associated Pneumonia and PaO2/FIO2 Diagnostic Accuracy: Changing the Paradigm?

Background: Ventilator-associated pneumonia (VAP) is associated to longer stay and poor outcomes. Lacking definitive diagnostic criteria, worsening gas exchange assessed by PaO2/FIO2 ≤ 240 in mmHg has been proposed as one of the diagnostic criteria for VAP. We aim to assess the adequacy of PaO2/FIO2 ≤ 240 to diagnose VAP. Methods: Prospective observational study in 255 consecutive patients with suspected VAP, clustered according to PaO2/FIO2 ≤ 240 vs. > 240 at pneumonia onset. The primary analysis was the association between PaO2/FIO2 ≤ 240 and quantitative microbiologic confirmation of pneumonia, the most reliable diagnostic gold-standard. Results: Mean PaO2/FIO2 at VAP onset was 195 ± 82; 171 (67%) cases had PaO2/FIO2 ≤ 240. Patients with PaO2/FIO2 ≤ 240 had a lower APACHE-II score at ICU admission; however, at pneumonia onset they had higher CPIS, SOFA score, acute respiratory distress syndrome criteria and incidence of shock, and less microbiological confirmation of pneumonia (117, 69% vs. 71, 85%, p = 0.008), compared to patients with PaO2/FIO2 > 240. In multivariate logistic regression, PaO2/FIO2 ≤ 240 was independently associated with less microbiological confirmation (adjusted odds-ratio 0.37, 95% confidence interval 0.15–0.89, p = 0.027). The association between PaO2/FIO2 and microbiological confirmation of VAP was poor, with an area under the ROC curve 0.645. Initial non-response to treatment and length of stay were similar between both groups, while hospital mortality was higher in patients with PaO2/FIO2 ≤ 240. Conclusion: Adding PaO2/FIO2 ratio ≤ 240 to the clinical and radiographic criteria does not help in the diagnosis of VAP. PaO2/FIO2 ratio > 240 does not exclude this infection. Using this threshold may underestimate the incidence of VAP.