Cardiovascular, Other
If a patient does not respond to several liters of isotonic crystalloid (usually 4 L or more), or if evidence of volume overload is present, the depressed cardiovascular system can be stimulated by inotropic and vasoconstrictive agents.
Dopamine
Dopamine is used to treat hypotension in fluid-resuscitated patients. It stimulates both adrenergic and dopaminergic receptors. The hemodynamic effect depends on the dose. Lower doses stimulate mainly dopaminergic receptors that produce renal and mesenteric vasodilation in healthy volunteers but probably have no measurable effect in patients who are critically ill. Higher doses produce cardiac stimulation, tachycardia, and vasoconstriction.
Norepinephrine (Levophed)
Norepinephrine, like dopamine, is used to treat hypotension after adequate fluid resuscitation. It stimulates beta1-adrenergic and alpha-adrenergic receptors, which increase arterial tone and cardiac contractility. As a result, systemic blood pressure and coronary blood flow increase with norepinephrine, though myocardial oxygen demand also may increase.
Once a response has been obtained, adjust the infusion rate to maintain a mean arterial pressure greater than 60 mm Hg. Blood pressures below this threshold are insufficient to perfuse vital organs; however, raising pressures much above 70 mm Hg with vasopressors does not further increase tissue blood flow.
Vasopressin (Pitressin)
Vasopressin has vasopressor and antidiuretic hormone (ADH) activity. Although it does not increase blood pressure in healthy subjects, it markedly increases vasomotor tone in patients with septic shock. It also increases water resorption at the distal renal tubular epithelium (ADH effect) and promotes smooth muscle contraction throughout the vascular bed of the renal tubular epithelium (vasopressor effects). Vasoconstriction also is increased in splanchnic, portal, coronary, cerebral, peripheral, pulmonary, and intrahepatic vessels.
Vasopressin is not yet routinely used to treat hypotension in septic shock. The dosage of vasopressin used for hypotension is 10% of that used to treat upper gastrointestinal bleeding from varices.
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Stages of sepsis based on American College of Chest Physicians/Society of Critical Care Medicine Consensus Panel guidelines.
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Pathogenesis of sepsis and multiorgan failure.
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Venn diagram showing overlap of infection, bacteremia, sepsis, systemic inflammatory response syndrome (SIRS), and multiorgan dysfunction.
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Acute respiratory distress syndrome (ARDS) present in this chest x-ray (CXR) film is a common organ system affected in multiorgan failure of sepsis.
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Acute respiratory distress syndrome (ARDS) shown in this chest x-ray (CXR) film is a common complication of septic shock. Note bilateral airspace infiltration, absence of cardiomegaly, vascular redistribution, and Kerley B lines.
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Organizing phase of diffuse alveolar damage (ARDS) secondary to septic shock shows diffuse alveolar injury and infiltration with inflammatory cells.
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Organizing diffuse alveolar damage in a different location showing disorganization of pulmonary architecture.
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A high-power view of organizing diffuse alveolar damage (ARDS) shows hyperplasia of type II pneumocytes and hyaline membrane deposits.
