The relationship between positive end-expiratory pressure and cardiac index in patients with acute respiratory distress syndrome

To evaluate the association between positive end-expiratory pressure (PEEP) and cardiac index in patients with acute respiratory distress syndrome (ARDS)

Colorectal and Prostate Cancer Risk in Diabetes: Metformin, an Actor behind the Scene

Both diabetes and cancer are prevalent diseases whose incidence rates are increasing worldwide, especially in countries that are undergoing rapid industrialization changes. Apparently, lifestyle risk factors including diet, physical inactivity and obesity play pivotal, yet preventable, roles in the etiology of both diseases. Epidemiological studies provide strong evidence that subjects with diabetes are at significantly higher risk of developing many forms of cancer and especially solid tumors. In addition to pancreatic and breast cancer, the incidence of colorectal cancer and prostate cancer is increased in type 2 diabetes. While diabetes (type 2) and cancer share many risk factors, the biological links between the two diseases are poorly characterized. In this review, we highlight the mechanistic pathways that link diabetes to colorectal and prostate cancer and the use of Metformin, a diabetes drug, to prevent and/or treat colorectal and prostate cancer. We review the role of AMPK activation in autophagy, oxidative stress, inflammation, apoptosis, and cell cycle progression.This publication was made possible by grant #NPRP 5-409-3-112 from the Qatar National Research Fund (a member of Qatar Foundation)

Thermodilution and Fick Cardiac Outputs Differ: Impact on Pulmonary Hypertension Evaluation

BACKGROUND: The relationship between thermodilution and indirect Fick cardiac output determination methods has not been well described

Dysfunctional BMPR2 signaling drives an abnormal endothelial requirement for glutamine in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is increasingly recognized as a systemic disease driven by alteration in the normal functioning of multiple metabolic pathways affecting all of the major carbon substrates, including amino acids. We found that human pulmonary hypertension patients (WHO Group I, PAH) exhibit systemic and pulmonary-specific alterations in glutamine metabolism, with the diseased pulmonary vasculature taking up significantly more glutamine than that of controls. Using cell culture models and transgenic mice expressing PAH-causing BMPR2 mutations, we found that the pulmonary endothelium in PAH shunts significantly more glutamine carbon into the tricarboxylic acid (TCA) cycle than wild-type endothelium. Increased glutamine metabolism through the TCA cycle is required by the endothelium in PAH to survive, to sustain normal energetics, and to manifest the hyperproliferative phenotype characteristic of disease. The strict requirement for glutamine is driven by loss of sirtuin-3 (SIRT3) activity through covalent modification by reactive products of lipid peroxidation. Using 2-hydroxybenzylamine, a scavenger of reactive lipid peroxidation products, we were able to preserve SIRT3 function, to normalize glutamine metabolism, and to prevent the development of PAH in BMPR2 mutant mice. In PAH, targeting glutamine metabolism and the mechanisms that underlie glutamine-driven metabolic reprogramming represent a viable novel avenue for the development of potentially disease-modifying therapeutics that could be rapidly translated to human studies

Targeted approaches to the treatment of pulmonary hypertension

Pulmonary arterial hypertension is a progressive and incurable disease. Over the past two decades, significant advances have been made in understanding and thus managing this disease. Multiple therapeutic options are currently available and optimizing the treatment of pulmonary arterial hypertension has become complex. Patients who meet the American College of Chest Physicians criteria for vasoresponsiveness can be safely and effectively treated with high-dose calcium channel blockers but require close follow up to assure durability of response. Patients with World Health Organization (WHO) functional class IV status and those with determinants of high risk for progression and death should be treated with an infused prostanoid agent without delay. These patients should also be referred early after stabilization for transplant evaluation. Patients with WHO functional class II status benefit from early initiation of oral therapies. Those with WHO functional class III status and lower determinants of risk for progression may receive treatment with one or more oral or inhaled agents, though many experts would advise early use of infused prostanoids for these patients as well

A systematic review of transition studies of pulmonary arterial hypertension specific medications.

Pulmonary arterial hypertension (PAH) is a progressive potentially fatal disease. Multiple pharmacologic options are now available, which facilitated transitions between different therapeutic options, although the evidence for such transitions has not been well described. We sought to review the evidence supporting the safety and/or efficacy of transitioning between PAH-specific medications. We performed a systematic review of all published studies in the Medline database between 1 January 2000 and 30 June 2016 reporting on any transition between the currently Food and Drug Administration (FDA)-approved PAH-specific medications. Studies reporting on three or more adult patients published in the English language reporting on transitions between FDA-approved PAH medications were extracted and tabulated. Forty-one studies met the selection criteria, nine of which included less than eight patients (and thus were reported separately in the supplement), for a total of 32 studies. Transitioning from parenteral epoprostenol to parenteral treprostinil appears to be safe and efficacious in patients who have less severe disease and more favorable hemodynamics. Transitioning from a prostacyclin analogue to an oral medication may be successful in patients who have favorable hemodynamics and stable disease. There is conflicting evidence supporting the transition from a parenteral to an inhaled prostacyclin analogue, even in patients who are on background oral therapy. Currently, the only evidence in support of transitioning between oral PDE5 inhibitors is from sildenafil to tadalafil. Patients on higher doses of sildenafil are more likely to fail. In patients with liver abnormalities due to bosentan or sitaxentan, the transition to ambrisentan appears to be safe and can result in clinical improvement. Studies regarding PAH medication transitions are limited. Patients who have less severe disease, better functional status, and are on lower medications doses may be more successful at transitioning

Lupus-Associated Pulmonary Arterial Hypertension: Variable Course and Importance of Prompt Recognition

We describe a critically ill young woman with systemic lupus erythematosus (SLE) presenting with circulatory shock, multiorgan dysfunction, and elevated right-sided heart pressures. She was found to have recurrent acute severe pulmonary arterial hypertension (PAH) in the setting of an SLE flare. Our report highlights the variable course that SLE-associated PAH can take in the same patient and the implications of this for instituting the most effective treatment approach with each episode. This report also highlights the potential for SLE-associated PAH to present with life-threatening symptoms requiring critical care level interventions. We also describe evidence-based therapies, which can result in significant improvement in symptoms, function, and long-term outcomes

Colorectal and Prostate Cancer Risk in Diabetes: Metformin, an Actor behind the Scene

Abstract Both diabetes and cancer are prevalent diseases whose incidence rates are increasing worldwide, especially in countries that are undergoing rapid industrialization changes. Apparently, lifestyle risk factors including diet, physical inactivity and obesity play pivotal, yet preventable, roles in the etiology of both diseases. Epidemiological studies provide strong evidence that subjects with diabetes are at significantly higher risk of developing many forms of cancer and especially solid tumors. In addition to pancreatic and breast cancer, the incidence of colorectal cancer and prostate cancer is increased in type 2 diabetes. While diabetes (type 2) and cancer share many risk factors, the biological links between the two diseases are poorly characterized. In this review, we highlight the mechanistic pathways that link diabetes to colorectal and prostate cancer and the use of Metformin, a diabetes drug, to prevent and/or treat colorectal and prostate cancer. We review the role of AMPK activation in autophagy, oxidative stress, inflammation, apoptosis, and cell cycle progression

The relationship between positive end-expiratory pressure and cardiac index in patients with acute respiratory distress syndrome

PURPOSE: To evaluate the association between positive end-expiratory pressure (PEEP) and cardiac index in patients with acute respiratory distress syndrome (ARDS). METHODS: This is a secondary cross-sectional analysis of the FACTT multi-center randomized controlled trial enrolling adult patients within 48 hours of ARDS onset. Patients randomized to the pulmonary artery catheter arm, who had PEEP and cardiac index measurements performed within a short period of each other during the first 3 days of the FACTT study enrollment were included in this study. Since FACTT had a 2×2 factorial design, half of the patients were in a ‘liberal fluids’ study arm, and the other half were in a ‘conservative fluids’ study arm. RESULTS: The final study population (833 measurements or observations, in 367 patients) was comparable to the original overall FACTT study population. The mean PEEP level used was 8.2 ± 3.4 cm H(2)O, and the mean cardiac index was 4.2 ± 1.2 liters/minute/m(2). There was no association between PEEP and cardiac index in patients with ARDS, even when adjusted for APACHE score, age, fluid study arm in FACTT, and sepsis. CONCLUSION: In patients with ARDS who are managed with liberal or conservative fluid management protocols, PEEP is not associated with lower cardiac index