Current opinion in critical care
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Curr Opin Crit Care · Dec 2004
ReviewThe relative adrenal insufficiency syndrome revisited: which patients will benefit from low-dose steroids?
Several clinical studies have given rise to optimism about low-dose steroid treatment in patients with sepsis. It reduces time to shock reversal and may even have a positive effect on mortality. The pathophysiology of the relative adrenal insufficiency syndrome has not yet been determined, and the usefulness of basal and stimulated cortisol levels in diagnosing this syndrome is still uncertain. This review will examine recent evidence to elucidate these questions. ⋯ It has been shown that low-dose corticosteroid administration to catecholamine-dependent patients in septic shock results in shock reversal. There seems to be a relative shortage of cortisol, because low-dose hydrocortisone administration resulting in cortisol levels as much as four times the already increased levels results in shock reversal. Strong evidence for a positive effect on mortality is still lacking, perhaps because of the relatively low number of patients investigated. A very important topic in interpreting studies is that total (free plus protein-bound) cortisol has been measured. Future studies should also measure free cortisol concentrations, which could add to our knowledge of the pathophysiology and treatment of the relative adrenal insufficiency syndrome. On the basis of current knowledge, there is no evidence to support a treatment strategy based on a random or stimulated cortisol level. At the moment, rapid hemodynamic improvement of catecholamine-dependent patients after the administration of low-dose corticosteroids still seems the best available clue to diagnosis.
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Recent studies demonstrating that mild therapeutic hypothermia can improve the outcome from several ischemic and traumatic insults have led to increased interest in the potential benefits of hypothermia after injury. Previous clinical studies, however, have suggested that hypothermia is detrimental to trauma patients. This most likely is a result of differences in the physiologic effects between uncontrolled exposure hypothermia and controlled therapeutic hypothermia. The laboratory and clinical data regarding traumatic hemorrhagic shock and hypothermia are presented, as well as a novel approach to the patient with exsanguinating trauma: suspended animation. Therapeutic hypothermia for traumatic brain injury is discussed. ⋯ The dichotomy between laboratory findings that show a benefit of hypothermia and clinical findings that suggest detrimental effects remains difficult to explain. For now, preventing hypothermia remains prudent. Suspended animation seems promising for patients with exsanguinating trauma. Clinical trials of mild hypothermia during hemorrhagic shock and suspended animation for exsanguination are indicated. Clinical trials of hypothermia for traumatic brain injury are in progress.
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Curr Opin Crit Care · Dec 2004
ReviewDefining the standard of care in randomized controlled trials of titrated therapies.
To discuss the appropriate standard of care in randomized controlled trials of titrated therapies in critically ill patients. ⋯ The incorporation of current practice patterns into randomized controlled trials of titrated therapies is essential for producing generalizable results and safeguarding patients.
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Vasopressin is one of the most important endogenously released stress hormones during shock. In this review, studies published in the past year that add to our understanding of the use of vasopressin in the ICU are discussed. ⋯ There is growing evidence that vasopressin infusion in septic shock is safe and effective. Several studies published this year support the hypothesis that vasopressin should be used as a continuous low-dose infusion (between 0.01 and 0.04 U/min in adults) and not titrated as a single vasopressor agent. However, multiple studies highlight the clinical equipoise that exists regarding the use of vasopressin in vasodilatory shock. Guidelines on management of septic shock recommend "cautious use of vasopressin pending further studies."