In: Septic Shock28 Oct 2014
Reversible myocardial depression has been demonstrated in human and canine septic shock. This myocardial depression occurs within the first several days of shock and is characterized by left ventricular (LV) dilatation and a decrease in LV efection fraction (EF). In survivors, these profound changes are transient, and the EF usually returns to normal in seven to ten days. comments
The pathogenetic mechanism of this early, transient LV dilatation and decrease in EF is not known. This decrease in EF is not associated with a global reduction in coronary blood flow nor with an elevated myocardial lactic acid production in humans, so myocardial ischemia cannot be implicated as the cause of the myocardial depression.
Previous data regarding a circulating cardiac depressant were derived almost exclusively from animal models of hemorrhagic shock; such models are thought to provide limited applicability to humans. A recent clinical study provided evidence that a circulating myocardial depressant substance (MDS) played an important pathophysiologic role in producing the reversible myocardial depression seen during septic shock in humans.
We used a modification of a previously described in vitro model of myocardial cell contractile performance to assay for the presence of MDS in serial blood samples. These samples were obtained from 50 consecutive (unselected) patients with possible septic shock admitted to our critical care unit as part of an ongoing prospective study of septic shock. Clinical, biochemical, and cardiac parameters that might distinguish patients with and without MDS were analyzed. The results of these analyses form the basis for this report.
From July 1985 to April 1987, 50 consecutive patients with possible septic shock (fever and hypotension) had serial studies of cardiovascular and metabolic function as part of an ongoing pro* spective study of human sepsis and septic shock in the critical care unit at the National Institutes of Health.
Blog invites submissions of review articles, reports on clinical techniques, case reports, conference summaries, and articles of opinion pertinent to the control of pain and anxiety in dentistry.