Correction to: Protective ventilation with high versus low positive end-expiratory pressure during one-lung ventilation for thoracic surgery (PROTHOR): study protocol for a randomized controlled trial.

After publication of the original article [1], the authors have notified us that two of the collaborator first and last names have been inverted in the "PROTHOR Investigators" table.

Protective ventilation with high versus low positive end-expiratory pressure during one-lung ventilation for thoracic surgery (PROTHOR): study protocol for a randomized controlled trial.

BACKGROUND: Postoperative pulmonary complications (PPC) may result in longer duration of in-hospital stay and even mortality. Both thoracic surgery and intraoperative mechanical ventilation settings add considerably to the risk of PPC. It is unclear if one-lung ventilation (OLV) for thoracic surgery with a strategy of intraoperative high positive end-expiratory pressure (PEEP) and recruitment maneuvers (RM) reduces PPC, compared to low PEEP without RM. METHODS: PROTHOR is an international, multicenter, randomized, controlled, assessor-blinded, two-arm trial initiated by investigators of the PROtective VEntilation NETwork. In total, 2378 patients will be randomly assigned to one of two different intraoperative mechanical ventilation strategies. Investigators screen patients aged 18 years or older, scheduled for open thoracic or video-assisted thoracoscopic surgery under general anesthesia requiring OLV, with a maximal body mass index of 35 kg/m2, and a planned duration of surgery of more than 60 min. Further, the expected duration of OLV shall be longer than two-lung ventilation, and lung separation is planned with a double lumen tube. Patients will be randomly assigned to PEEP of 10 cmH2O with lung RM, or PEEP of 5 cmH2O without RM. During two-lung ventilation tidal volume is set at 7 mL/kg predicted body weight and, during OLV, it will be decreased to 5 mL/kg. The occurrence of PPC will be recorded as a collapsed composite of single adverse pulmonary events and represents the primary endpoint. DISCUSSION: PROTHOR is the first randomized controlled trial in patients undergoing thoracic surgery with OLV that is adequately powered to compare the effects of intraoperative high PEEP with RM versus low PEEP without RM on PPC. The results of the PROTHOR trial will support anesthesiologists in their decision to set intraoperative PEEP during protective ventilation for OLV in thoracic surgery. TRIAL REGISTRATION: The trial was registered in clinicaltrials.gov ( NCT02963025 ) on 15 November 2016.

Combination of ECMO and cytokine adsorption therapy for severe sepsis with cardiogenic shock and ARDS due to Panton-Valentine leukocidin-positive Staphylococcus aureus pneumonia and H1N1.

Sepsis-induced cardiogenic shock in combination with severe acute respiratory failure represents a life-threatening combination that is often refractory to the conventional methods of treatment. We describe the case of a 33-year-old patient who developed acute cardiovascular collapse and ARDS secondary to superinfection of Panton-Valentine leukocidin-positive Staphylococcus aureus and H1N1 pneumonia who underwent successful combination therapy for severe sepsis-related cardiomyopathy and respiratory failure using extracorporeal membrane oxygenation and cytokine adsorption therapy.

Exhaled nitric oxide and carbon monoxide in mechanically ventilated brain-injured patients.

The inflammatory influence and biological markers of prolonged mechanical-ventilation in uninjured human lungs remains controversial. We investigated exhaled nitric oxide (NO) and carbon monoxide (CO) in mechanically-ventilated, brain-injured patients in the absence of lung injury or sepsis at two different levels of positive end-expiratory pressure (PEEP). Exhaled NO and CO were assessed in 27 patients, without lung injury or sepsis, who were ventilated with 8 ml kg(-1) tidal volumes under zero end-expiratory pressure (ZEEP group, n = 12) or 8 cm H2O PEEP (PEEP group, n = 15). Exhaled NO and CO was analysed on days 1, 3 and 5 of mechanical ventilation and correlated with previously reported markers of inflammation and gas exchange. Exhaled NO was higher on day 3 and 5 in both patient groups compared to day 1: (PEEP group: 5.8 (4.4-9.7) versus 11.7 (6.9-13.9) versus 10.7 (5.6-16.6) ppb (p < 0.05); ZEEP group: 5.3 (3.8-8.8) versus 9.8 (5.3-12.4) versus 9.6 (6.2-13.5) ppb NO peak levels for days 1, 3 and 5, respectively, p < 0.05). Exhaled CO remained stable on day 3 but significantly decreased by day 5 in the ZEEP group only (6.3 (4.3-9.0) versus 8.1 (5.8-12.1) ppm CO peak levels for day 5 versus 1, p < 0.05). The change scores for peak exhaled CO over day 1 and 5 showed significant correlations with arterial blood pH and plasma TNF levels (r s = 0.49, p = 0.02 and r s = -0.51 p = 0.02, respectively). Exhaled NO correlated with blood pH in the ZEEP group and with plasma levels of IL-6 in the PEEP group. We observed differential changes in exhaled NO and CO in mechanically-ventilated patients even in the absence of manifest lung injury or sepsis. These may suggest subtle pulmonary inflammation and support application of real time breath analysis for molecular monitoring in critically ill patients.

Effect of a glutathione S-transferase inhibitor on oxidative stress and ischemia-reperfusion-induced apoptotic signalling of cultured cardiomyocytes.

Oxidative stress and ischemia-reperfusion (I/R) injury are crucial in the pathogenesis of cardiovascular diseases. The antioxidant glutathione S-transferase (GST) is responsible for the high-capacity metabolic inactivation of electrophilic compounds and toxic substrates. The main objective of the present study was to examine the effect of GST inhibition (with the administration of ethacrynic acid [EA]) on the viability and apoptosis of cardiomyocytes when these cells are exposed to various stress components of I/R and mitogen-activated protein kinase (c-Jun N-terminal kinase, p38 and extracellular signal-regulated kinase [ERK]) inhibitors. The primary culture of neonatal rat cardiomyocytes was divided into six experimental groups: control group of cells (group 1), cells exposed to H(2)O(2) (group 2), I/R (group 3), I/R and EA (group 4), H(2)O(2) coupled with EA (group 5), and EA alone (group 6). The viability of cardiomyocytes was determined using a colorimetric MTT assay. The apoptosis ratio was evaluated via fluorescein isothiocyanate-labelled annexin V and propidium iodide staining. c-Jun N-terminal kinase, p38, Akt/protein kinase B and ERK/p42-p44 transcription factors were monitored with flow cytometry. c-Jun N-terminal kinase activation increased due to GST inhibition during I/R. EA administration led to a significant increase in p38 activation following both H(2)O(2) treatment and I/R. ERK phosphorylation increased when GST was exposed to I/R. A pronounced decrease in Akt phosphorylation was observed when cells were cotreated with EA and H(2)O(2). GST plays an important role as a regulator of mitogen-activated protein kinase pathways in I/R injury.

Basal and nitroglycerin-induced exhaled nitric oxide before and after cardiac surgery with cardiopulmonary bypass.

BACKGROUND: Exhaled nitric oxide (NO) may reflect NO production and consumption but the pulmonary origin of NO in exhaled gas is not clear. There are also conflicting data on exhaled NO after cardiopulmonary bypass (CPB). Because intravenous nitrovasodilators increase exhaled NO by conversion to NO in the lung, we measured basal and nitroglycerin (GTN)-induced exhaled NO in patients having low-risk coronary artery bypass graft (CABG) operations using routine CPB. We reasoned that GTN-induced exhaled NO would be a primarily vascular mechanism, which would contrast with the airway epithelial origin of basal exhaled NO, and that they might be differentially influenced by CPB. METHODS: Breath-to-breath concentrations of gas phase NO were measured in 12 CABG patients before and 1, 3 and 6 h after CPB. After the baseline measurements, three increasing doses of 1, 2 and 3 micro g kg(-1) intravenous GTN were given by a central venous catheter and exhaled NO and haemodynamic responses were recorded. RESULTS: Intravenous administration of 1, 2 and 3 micro g kg(-1) doses of GTN produced a dose-dependent increase in exhaled NO and a reduction in systemic blood pressure. Baseline exhaled NO remained unchanged. Exhaled NO but not blood pressure responses were reduced 1 and 3 h after CPB. CONCLUSIONS: The capacity of the lungs to increase exhaled NO in response to intravenous GTN is reduced after CPB, suggesting microvascular injury and/or atelectasis after routine open-heart surgery.

Transplant atherosclerosis: role of phenotypic modulation of vascular smooth muscle by nitric oxide.

Occlusive accelerated atherosclerosis of coronary grafts is the predominant factor that limits longevity of heart transplant recipients. This form of vascular disease affects both the large epicardial and the smaller intramyocardial vessels, leading to characteristic clinical presentation that necessitates the use of sophisticated techniques for their accurate detection. Accelerated atherosclerosis after transplantation is a multifactorial disease with many events contributing to its progression. The initial vascular injury associated with ischemia-reperfusion appears to aggravate preexisting conditions in the donor vasculature in addition to activation of new immunological and nonimmunological mechanisms. Throughout these events, the endothelium remains a primary target of cell- and humoral-mediated injury. Changes in the vascular intima leads to alterations in vascular smooth muscle cell (VSMC) physiology, resulting in VSMC phenotypic modulation with the orchestration of a broad spectrum of growth and inflammatory reactions, which might be a healing response to vascular injury. Endogenous nitric oxide (NO) pathways regulate a multiplicity of cellular mechanisms that play a major role in determining the structure and function of the vessel wall during normal conditions and during remodeling associated with accelerated atherosclerosis. Recently identified signaling pathways, including mitogen-activated protein kinase, cGMP-dependent protein kinase, phosphatidylinositol 3-kinase, and transcriptional events in which nuclear factor kappa B and activator protein 1 take part, can be associated with NO modulation of cell cycle perturbations and phenotypic alteration of VSMC during accelerated atherosclerosis. This article reviews recent progress covering the aforementioned matters. We start by summarizing the clincal aspects and pathogenesis of accelerated atherosclerosis associated with transplantation, including clinical presentation and detection. This summary is followed by a discussion of the multiple factors of the disease process, including immunological and nonimmunolgical contributions. The next section focuses on cellular responses of the VSMCs relevant to lesion formation, with special emphasis on classical and recent paradigms of phenotypic modulation of these cells. To examine the influence of NO on VSMC phenotypic modulation and consequent lesion development, we briefly overview characteristics of NO production in the normal coronary vascular bed and the changes in endogenous NO release and activity during atherosclerosis. This overview is followed by a section covering molecular mechanisms whereby NO regulates a range of signaling pathways, transcriptional events underlying cell cycle perturbation, and phenotypic alteration of VSMC in accelerated atherosclerosis.

A redox-based mechanism for nitric oxide-induced inhibition of DNA synthesis in human vascular smooth muscle cells.

1. The current study explored potential redox mechanisms of nitric oxide (NO)-induced inhibition of DNA synthesis in cultured human and rat aortic smooth muscle cells. 2. Exposure to S-nitrosothiols, DETA-NONOate and NO itself inhibited ongoing DNA synthesis and S phase progression in a concentration-dependent manner, as measured by thymidine incorporation and flow cytometry. Inhibition by NO donors occurred by release of NO, as detected by chemiluminescence and judged by the effects of NO scavengers, haemoglobin and cPTIO. 3. Co-incubation with redox compounds, N-acetyl-L-cysteine, glutathione and L-ascorbic acid prevented NO inhibition of DNA synthesis. These observations suggest that redox agents may alternatively attenuate NO bioactivity extracellularly, interfere with intracellular actions of NO on the DNA synthesis machinery or restore DNA synthesis after established inhibition by NO. 4. Recovery of DNA synthesis after inhibition by NO was similar with and without redox agents suggesting that augmented restoration of DNA synthesis is an unlikely mechanism to explain redox regulation. 5. Study of extracellula interactions revealed that all redox agents potentiated S-nitrosothiol decomposition and NO release. 6. Examination of intracellular NO bioactivity showed that as opposed to attenuation of NO inhibition of DNA synthesis by redox agents, there was no inhibition (potentiation in the presence of ascorbic acid) of soluble guanylate cyclase (sGC) activation judged by cyclic GMP accumulation in rat cells. 7. These data provide evidence that NO-induced inhibition of ongoing DNA synthesis is sensitive to redox environment. Redox processes might protect the DNA synthesis machinery from inhibition by NO, in the setting of augmented liberation of biologically active NO from NO donors.

Differential regulation of DNA synthesis by nitric oxide and hydroxyurea in vascular smooth muscle cells.

We investigated the influence of nitrovasodilators on DNA synthesis in cultured human aortic smooth muscle cells and explored the hypothesis that nitric oxide (NO) is directly involved in mediating the inhibitory effects of hydroxyurea on DNA synthesis. Both NO and hydroxyurea inhibited ongoing DNA synthesis and S phase progression in our cells. Exogenous deoxynucleosides partially reversed this inhibition, suggesting that ribonucleotide reductase is a primary target for both NO and hydroxyurea. Nitrovasodilators inhibited DNA synthesis by releasing NO, as detected by chemiluminescence and as shown by the reversal of DNA synthesis inhibition by NO scavengers. This inhibition appears to occur via a cGMP-independent mechanism. In contrast, hydroxyurea did not produce a detectable NO signal, and NO scavengers had no influence on its inhibition of DNA synthesis, suggesting that NO does not mediate the inhibitory action of hydroxyurea in our system. Furthermore, the action of nitrovasodilators and hydroxyurea on DNA synthesis differed according to redox sensitivity. The redox agents N-acetyl-L-cysteine and ascorbate reversed NO inhibition of DNA synthesis and had no effect on DNA synthesis inhibition caused by hydroxyurea.

Role of oxidant stress in cytokine-induced activation of NF-kappaB in human aortic smooth muscle cells.

The transcription factor nuclear factor-kappaB (NF-kappaB) has been implicated in inflammatory and proliferative vascular mechanisms. Activated NF-kappaB has been documented in human atherosclerotic lesions, and its activation in human vascular smooth muscle cells (SMC) by cytokines has been reported. However, intracellular mechanisms mediating NF-kappaB activation in human SMC are poorly understood. The aim of this study was to explore the potential role of reactive oxygen species and oxidant stress as signaling events in cytokine-induced NF-kappaB activation. Western blot analysis revealed the presence of inhibitory protein I-kappaBalpha in resting human aortic SMC, which was rapidly phosphorylated and degraded on exposure to interleukin-1beta (IL-1beta) followed by NF-kappaB translocation to the nucleus. IL-1beta had no effect on two measures of intracellular oxidant stress, fluorescence generated by the oxidation of 2',7'-dichlorodihydrofluorescin to dichlorofluorescein (DCF) or changes in intracellular sulfhydryl content. N-acetylcysteine (NAC) a membrane-permeant antioxidant, which augmented intracellular sulfhydryl content and inhibited H(2)O(2)-induced DCF fluorescence, had no effect on cytokine-induced NF-kappaB activation. In contrast to NAC, the metal chelators pyrrolidine dithiocarbamate and diethyldithiocarbamate attenuated IL-1beta-induced NF-kappaB activation but had no effect on intracellular sulfhydryl content. Treatment of the cells with the oxidant H(2)O(2) caused an increase in DCF fluorescence and decreased intracellular sulfhydryl content but had no effect on I-kappaBalpha or NF-kappaB. In conclusion, this study suggests that oxidant stress may not play a major role in cytokine-induced activation of NF-kappaB in human aortic SMC and that oxidants may not be primary activators of NF-kappaB in these cells.

Cross-tolerance between endogenous nitric oxide and exogenous nitric oxide donors.

It is still unclear whether cross-tolerance develops between endogenously produced nitric oxide and exogenous nitric oxide donors. Thus, cGMP accumulation was determined in cultured aortic smooth muscle cells exposed to a nitric oxide source. Exposure of human, rat, rabbit, porcine or bovine smooth muscle cells to sodium nitroprusside led to a time- and concentration-dependent development of tolerance. In rat aortic smooth muscle cells, cross-tolerance developed between the sodium nitroprusside and S-nitroso-N-acetylpenicillamine, but not between sodium nitroprusside and atriopeptin. In addition, when rat aortic smooth muscle cells were treated with endotoxin or interleukin-1beta, they displayed lower sodium nitroprusside-induced cGMP accumulation as compared to control cells. When rat aortic smooth muscle cells were exposed to sodium nitroprusside for 12 h they displayed a decreased ability to accumulate cGMP in response to endothelium-derived nitric oxide released from bovine aortic endothelial cells. In addition, co-cultures of rat aortic smooth muscle cells with bovine aortic endothelial cells showed an L-nitroarginine methylester-sensitive decrease in sodium nitroprusside-induced cGMP accumulation compared to single rat aortic smooth muscle cell cultures. We conclude that cross-tolerance between endothelium-derived nitric oxide and exogenously applied nitric oxide donors occurs in vitro.