Critical care : the official journal of the Critical Care Forum
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Sepsis-associated encephalopathy (SAE) resembles metabolic encephalopathies but with a difference: there is the potential for enduring brain damage/dysfunction. The pathogenesis of SAE is likely multifactorial. ⋯ Mild cases of SAE are often completely reversible, but there is increasing evidence that severe cases have neurological sequelae. A better understanding of the mechanisms may lead to brain-sparing, protective strategies.
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Four ethical issues loom over the study by Lieberman and colleagues--the absence of informed consent, the study being non-interventional in situations that typically call for life-saving interventions, the bias involved in doctors that study their own problematic practice and monopoly over intensive care unit triage, and ageism. We learn that the Israeli doctors in this study never make no-treatment decisions regarding patients in need of mechanical ventilation. They are complicit with botched standards of care for these patients, however, accepting without much doubt an ethos of scarce resources and poor managerial habits. The main two practical lessons to be taken from this study are that, for patients in need of mechanical ventilation, compromised care is better than a policy of intubation only when the intensive care unit is available, and that vigorous efforts are needed in order to extirpate ageism.
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Intra-abdominal hypertension is common in critically ill patients and is associated with increased morbidity and mortality. The optimal ventilation strategy remains unclear in these patients. We examined the effect of positive end-expiratory pressures (PEEP) on functional residual capacity (FRC) and oxygen delivery in a pig model of intra-abdominal hypertension. ⋯ In a pig model of intra-abdominal hypertension, PEEP up to 15 cmH2O did not prevent the FRC decline caused by intra-abdominal hypertension and was associated with reduced oxygen delivery as a consequence of reduced cardiac output. This implies that PEEP levels inferior to the corresponding intra-abdominal pressures cannot be recommended to prevent FRC decline in the setting of intra-abdominal hypertension.
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Editorial Comment
Extracorporeal gas exchange in acute lung injury: step by step towards expanded indications?
Extracorporeal membrane oxygenation (ECMO) is widely accepted as a rescue therapy in patients with acute life-threatening hypoxemia in the course of severe acute respiratory distress syndrome (ARDS). However, possible side effects and complications are considered to limit beneficial outcome effects. Therefore, widening indications with the aim of reducing ventilator induced lung injury (VILI) is still controversial. ⋯ From a strategic perspective, this is another small but useful step towards implementing extracorporeal gas exchange for the prevention of VILI. It is already common sense that the prevention of acute life-threatening hypoxemia usually outweighs the risks of this technique. The next step should be to prove that prevention of life-threatening VILI balances the risks too.
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Pulse-pressure variation (PPV) due to increased right ventricular afterload and dysfunction may misleadingly suggest volume responsiveness. We aimed to assess prediction of volume responsiveness with PPV in patients with increased pulmonary artery pressure. ⋯ Both early after cardiac surgery and in septic shock, patients with increased pulmonary artery pressure respond poorly to fluid administration. Under these conditions, PPV cannot be used to predict fluid responsiveness. The frequent reduction in right ventricular EF when SV did not increase suggests that right ventricular dysfunction contributed to the poor response to fluids.