What is the most common cause of septic shock?

The most common cause of septic shock is indeed associated with Gram-negative bacteria. Septic shock occurs as a result of a systemic inflammatory response to infection, leading to profound circulatory, cellular, and metabolic abnormalities.

Gram-negative bacteria, such as Escherichia coli and Klebsiella species, are known for producing endotoxins, particularly lipopolysaccharides (LPS), which can trigger a potent immune response. This response can result in the release of pro-inflammatory cytokines, leading to vasodilation, increased vascular permeability, and ultimately a drop in blood pressure, all characteristic of septic shock.

While Gram-positive bacteria can also cause septic shock, they are generally less common as a sole cause compared to Gram-negative bacteria. Fungal infections and viral infections are less frequently associated with septic shock compared to bacterial infections. Thus, understanding the pathophysiological mechanisms behind these infections helps clarify why Gram-negative bacteria are a predominant cause in these clinical scenarios.