Critical care : the official journal of the Critical Care Forum
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Pulmonary capillary pressure (PCP), together with the time constants of the various vascular compartments, define the dynamics of the pulmonary vascular system. Our objective in the present study was to estimate PCPs and time constants of the vascular system in patients with idiopathic pulmonary arterial hypertension (IPAH), and compare them with these measures in patients with acute respiratory distress syndrome (ARDS). ⋯ The PCP in IPAH patients is greater than normal but methodological limitations related to the occlusion technique may limit interpretation of these data in isolation. Different disease processes may result in different times for arterial emptying, with resulting implications for the methods available for estimating PCP.
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Comparative Study
Minimal instructions improve the performance of laypersons in the use of semiautomatic and automatic external defibrillators.
There is evidence that use of automated external defibrillators (AEDs) by laypersons improves rates of survival from cardiac arrest, but there is no consensus on the optimal content and duration of training for this purpose. In this study we examined the use of semiautomatic or automatic AEDs by laypersons who had received no training (intuitive use) and the effects of minimal general theoretical instructions on their performance. ⋯ Untrained laypersons can use semiautomatic and automatic AEDs sufficiently quickly and without instruction. After one use and minimal instructions, improvements in practical performance were significant. All tested laypersons were able to deliver the first shock in under 1 min.
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Acute lung injury or acute respiratory distress syndrome (ALI/ARDS) in the course of sepsis is thought to result from increased pulmonary capillary permeability and resultant edema. However, when the edema is assessed at the bedside by measuring the extravascular thermal volume by transpulmonary dilution, some ALI/ARDS patients with sepsis may have normal extravascular lung water (EVLW). Conversely, a raised EVLW may be present even when criteria for ALI/ARDS are not met, according to GS Martin and colleagues in this issue of Critical Care. ⋯ Overhydration is particularly difficult to recognize. Additional diagnostics may be required to improve the delineation of pulmonary edema so as to redirect or redefine treatment and improve patient morbidity and, perhaps, mortality. Monitoring EVLW by single transpulmonary thermal dilution, for instance, might have a future role in this process.
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Review Comparative Study
Clinical review: Vasopressin and terlipressin in septic shock patients.
Vasopressin (antidiuretic hormone) is emerging as a potentially major advance in the treatment of septic shock. Terlipressin (tricyl-lysine-vasopressin) is the synthetic, long-acting analogue of vasopressin, and has comparable pharmacodynamic but different pharmacokinetic properties. Vasopressin mediates vasoconstriction via V1 receptor activation on vascular smooth muscle. ⋯ Of concern is a constant decrease in cardiac output and oxygen delivery, the consequences of which in terms of development of multiple organ failure are not yet known. Terlipressin (one or two boluses of 1 mg) has similar effects, but this drug has been used in far fewer patients. Large randomized clinical trials should be conducted to establish the utility of these drugs as therapeutic agents in patients with septic shock.
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Rhabdomyolysis ranges from an asymptomatic illness with elevation in the creatine kinase level to a life-threatening condition associated with extreme elevations in creatine kinase, electrolyte imbalances, acute renal failure and disseminated intravascular coagulation. Muscular trauma is the most common cause of rhabdomyolysis. ⋯ The most sensitive laboratory finding of muscle injury is an elevated plasma creatine kinase level. The management of patients with rhabdomyolysis includes early vigorous hydration.