The current management of septic shock

Abstract

This is a review of the management of septic shock that suggests an approach to treatment (ABCDEF: Airway, Breathing, Circulation, Drugs, Evaluate the source of sepsis, Fix the source of sepsis) for clinicians. The incidence of septic shock is increasing and mortality ranges from 30% to 70%. The commonest sources of infection are lung (25%), abdomen (25%), and other sources. Septic shock occurs because of highly complex interactions between the infecting microorganism(s) and the responses of the human host. The innate immune response is rapidly followed by the more specific adaptive immune response. Septic shock is characterized by alterations in the coagulant/anticoagulant balance such that there is a more pro-coagulant phenotype. Lung protective ventilation (which means the use of relatively low tidal volumes of 4 -6 mL/kg ideal body weight) is recommended for treatment of patients who have septic shock. Rivers early goal-directed therapy is recommended because it showed a significant increase in survival. Surviving Sepsis guidelines recommend resuscitation of septic shock with either crystalloid or colloid. Patients who have septic shock should be treated with intravenous broad-spectrum antibiotics as rapidly as possible and certainly within one hour. Activated protein C (APC) is a vitamin K dependent serine protease that is an anticoagulant and is also cytoprotective and anti-inflammatory. APC (24 mg/kg/hour infusion for 96 hours) decreased mortality (APC 25% vs placebo 31%, relative risk 0.81P=0.005) and improved organ dysfunction in patients at high risk of death (e.g. APACHE II >25 [APC 31% vs placebo 44%]). APC is not recommended to treat surgical patients who have one organ system dysfunction. In 2006, the European regulatory authority indicated that there must be another randomized placebo-controlled trial of APC to further establish efficacy as assessed by mortality reduction. Vasopressin is a key stress hormone in response to hypotension. The VASST study was a randomized trial of vasopressin versus norepinephrine in septic shock. There was no difference in mortality between vasopressin versus norepinephrine-treated patients (35% versus 39% respectively). In patients who had less severe septic shock, patients treated with vasopressin may have lowered mortality compared with norepinephrine (26% vs 36%). Annane et al. found that hydrocortisone plus fludrocortisone (compared to placebo) was associated with lower mortality in patients who had an inadequate response to corticotropin stimulation test (mortality 53% vs 63% respectively). Sprung et al. did a randomized controlled trial of hydrocortisone (50 mg intravenously every 6 hours) compared to placebo (CORTICUS) to address lingering questions regarding the Annane trial. There was no difference in mortality (39.2% hydrocortisone vs 36.1%) or organ dysfunction. Several randomized controlled trials of intensive insulin versus conventional insulin in the critically ill have yielded conflicting results and do not support the routine use of intensive insulin in the ancillary management of septic shock. A recent randomized controlled trial of intensive versus less intensive renal support in patients who had acute kidney injury found no difference in mortality (53.6% vs 51.5% respectively), duration of renal support, or rates of recovery of renal and non-renal organ dysfunction.