The cuff-leak test: what are we measuring?

Stridor is one of the most frequent causes of early extubation failure. The cuff-leak test may help to identify patients at risk to develop post-extubation laryngeal edema. However the discrimination power of the cuff-leak test is highly variable and can be use, at best, to detect patients at risk to develop edema but should not be used to postpone extubation as tracheal extubation can still be successful in many patients with a positive test. In this editorial, the author discuss the factors influencing the leak and hence its predictive value

Abdominal compartment syndrome

SCOPUS: ed.jinfo:eu-repo/semantics/publishe

Can passive leg raising be used to guide fluid administration?

Predicting fluid responsiveness has become a topic of major interest. Measurements of intravascular pressures and volumes often fail to predict the response to fluids, even though very low values are usually associated with a positive response to fluids. Dynamic indices reflecting respiratory-induced variations in stroke volume have been developed; however, these cannot be used in patients with arrhythmia or with spontaneous respiratory movements. The passive leg raising (PLR) test has been suggested to predict fluid responsiveness. PLR induces an abrupt increase in preload due to autotransfusion of blood contained in capacitance veins of the legs, which leads to an increase in cardiac output in preload-dependent patients. This commentary discusses some of the technical issues related to this test

Optimal management of the high risk surgical patient: beta stimulation or beta blockade?

Several groups of investigators have shown that peri-operative goal directed therapy (GDT) may reduce mortality in high-risk surgical patients. GDT usually requires the use of beta-adrenergic agents, however, and these may also carry the risk of cardiac ischemia, especially in patients with ischemic diseases. In this commentary, we will discuss the apparent contradiction between studies showing beneficial effects of GDT in high-risk surgical patients and studies showing the benefit of beta-blockade in high-risk surgery. One of the key differences between both types of studies is that GDT is applied in patients with high risk of postoperative death, excluding patients with cardiac ischemic disease, while studies reporting beneficial effects of beta-blockade have investigated patients with high risk of cardiac ischemia but moderate risk of death related to the surgical procedure itself. It is likely that beta-blockade should be proposed in patients with moderate risk of death, whereas GDT using fluids and inotropic agents should be applied in patients with high risk of peri-operative death. Monitoring central venous oxygen saturation may be useful to individualize therapy, but further studies are required to validate this option

Why do pulse pressure variations fail to predict the response to fluids in acute respiratory distress syndrome patients ventilated with low tidal volume?

Respiratory-associated variations in stroke volume and pulse pressure are frequently used to predict the response to fluid administration. However, it has been demonstrated that low tidal volume ventilation may limit their use in patients with acute respiratory distress syndrome (ARDS). In this issue, a trial investigates the value of pulse pressure variation to predict fluid responsiveness in a large series of patients with ARDS ventilated according to current guidelines

Microvascular dysfunction as a cause of organ dysfunction in severe sepsis

Reduced microvascular perfusion has been implicated in organ dysfunction and multiple organ failure associated with severe sepsis. The precise mechanisms underlying microvascular dysfunction remain unclear, but there are considerable experimental data showing reduced microcirculatory flow, particularly of small vessels, and increased heterogeneity. With the development of newer imaging techniques, human studies have also been conducted and have given rise to similar findings. Importantly, the degree of microvascular disturbance and its persistence is associated with poorer outcomes. The ability to influence these changes may result in better outcomes and bedside systems, enabling direct visualization of the microcirculation, which will help in the assessment of ongoing microcirculatory dysfunction and its response to established and new therapeutic interventions

The International Sepsis Forum's controversies in sepsis: my initial vasopressor agent in septic shock is dopamine rather than norepinephrine

Norepinephrine (noradrenaline) and dopamine are commonly used first-line vasopressor agents in the treatment of patients with septic shock. Recently increasing interest has focused on whether one or other of these agents is superior in terms of improving outcome. Studies have looked particularly at the possible local effects of the vasopressors on splanchnic circulation, because evidence suggests that this area is important in the development and maintenance of septic shock. However, the many studies performed have yielded conflicting data and there is, as yet, little evidence to support one drug over the other in terms of their splanchnic effects. Overall, though, dopamine has many assets that make it a good first-line drug when compared with norepinephrine, and these are highlighted in the present, brief commentary