critical care medicine
Sepsis and Septic Shock
Treatment of Sepsis and Septic Shock
Perfusion restored with IV fluids and sometimes vasopressors Oxygen support Broad-spectrum antibiotics Source control Sometimes other supportive measures (eg, corticosteroids,insulin) Patients with septic shock should be treated in an ICU. The following should be monitored frequently (as often as hourly): Volume status using central venous pressure (CVP), pulmonary artery occlusion pressure (PAOP), serial ultrasound and/or central venous oxygenation saturation (ScvO2) Arterial blood gases (ABGs) Blood glucose, lactate, and electrolyte levels Renal function Arterial oxygen saturation should be measured continuously via pulse oximetry. Urine output, a good indicator of renal perfusion, should be measured (in general, indwelling urinary catheters should be avoided unless they are essential). The onset of oliguria (eg,<about 0.5 mL/kg/hour) or anuria, or rising creatinine may signal impending renal failure. Following evidence-based guidelines and formal protocols for timely diagnosis and treatment of sepsis has been shown to decrease mortality and length of stay in the hospital ( Treatment references ). IV fluids are the first method used to restore perfusion. Balanced isotonic crystalloid is preferred. Some clinicians addalbuminto the initial fluid bolus in patients with severe sepsis or septic shock;albuminis more expensive than crystalloid but is generally a safe complement to crystalloid. Starch-based fluids (eg,hydroxyethyl starch) are associated with increased mortality and should not be used. Initially, 1 L of crystalloid is given rapidly. Most patients require a minimum of 30 mL/kg in the first 4 to 6 hours. However, the goal of therapy is not to administer a specific volume of fluid but to achieve tissue reperfusion without causing pulmonary edema due to fluid overload. Estimates of successful reperfusion include ScvO2 and lactate clearance (ie, percent change in serum lactate levels over 6 to 8 hours). Target ScvO2 is≥70%. Lactate clearance target is 10 to 20%. Risk of pulmonary edema can be controlled by optimizing preload; fluids should be given until CVP reaches 8 mm Hg (10 cm water) or PAOP reaches 12 to 15 mm Hg; however, patients on mechanical ventilation may require higher CVP levels. The quantity of fluid required often far exceeds the normal blood volume and may reach 10 L over 4 to 12 hours. PAOP or echocardiography can identify limitations in left ventricular function and incipient pulmonary edema due to fluid overload. Point-of-care ultrasound can also be used to assess volume status, including inferior vena cava (IVC) distention or collapsibility, cardiac function, and presence of pulmonary edema. If a patient with septic shock remains hypotensive after CVP or PAOP has been raised to target levels,norepinephrine(highly individualized dosing) orvasopressin(up to 0.03 units/minute) may be given to increase mean blood pressure (BP) to at least 65 mm Hg.Epinephrinemay be added if a second medication is needed. However, vasoconstriction caused by higher doses of these medications may cause organ hypoperfusion and acidosis. Oxygen is given by mask or nasal prongs. Tracheal intubation and mechanical ventilation may be needed subsequently for respiratory failure (see Mechanical ventilation in ARDS ). Parenteral antibiotics should be given as soon as possible after specimens of blood, body fluids, and wound sites have been taken for Gram stain and culture. Prompt empiric therapy, started immediately after suspecting sepsis, is essential and may be lifesaving. Antibiotic selection requires an educated guess based on the suspected source (eg, pneumonia, urinary tract infection), clinical setting, knowledge or suspicion of causative organisms and of sensitivity patterns common to that specific inpatient unit or institution, and previous culture results. Typically, broad-spectrum gram-positive and gram-negative bacterial coverage is used initially; immunocompromised patients should also receive an empiric antifungal medication. There are many possible starting regimens; when available, institutional trends for infecting organisms and their antibiotic susceptibility patterns (antibiograms) should be used to select empiric treatment. In general, common antibiotics for empiric gram-positive coverage includevancomycinandlinezolid. Empiric gram-negative coverage has more options and includes broad-spectrum penicillins (eg,piperacillin/tazobactam), 3rd- or 4th-generation cephalosporins, imipenems, and aminoglycosides. Initial broad-spectrum coverage is narrowed based on culture and sensitivity data. Knowledge of institution- and care unit–specific trends in infecting organisms and their antimicrobial sensitivity is an important guide to empiric antibiotic selection. The source of infection should be controlled as early as possible. IV and urinary catheters and endotracheal tubes should be removed if possible or changed. Abscesses must be drained, and necrotic and devitalized tissues (eg, gangrenous gallbladder, necrotizing soft-tissue infection) must be surgically excised. If excision is not possible (eg, because of comorbidities or hemodynamic instability), surgical drainage may help. If the source is not controlled, the patient’s condition will continue to deteriorate despite antibiotic therapy. Normalization of blood glucose improves outcome in critically ill patients, even those not known to be diabetic, because hyperglycemia impairs the immune response to infection. A continuous IVinsulininfusion (starting dose 1 to 4 units/hour) is titrated to maintain glucose between 110 and 180 mg/dL (7.7 to 9.9 mmol/L). This approach necessitates frequent (eg, every 1 to 4 hours) glucose measurement. < 400 mg IV per day in divided doses) is indicated for patients with adrenal insufficiency documented by cortisol testing. However, in refractory septic shock (systolic blood pressure < 90 mm Hg for more than 1 hour following both adequate fluid resuscitation and vasopressor administration, attainment of source control, and antibiotics), no cortisol testing is required before starting corticosteroid therapy ( Treatment references ). Continued treatment is based on patient response. 1.Bhattacharjee P, Edelson DP, Churpek MM: Identifying patients with sepsis on the hospital wards.Chest151:898–907, 2017. doi: 10.1016/j.chest.2016.06.02T 2.Annane D, Pastores SM, Rochwerg B, et al: Guidelines for the diagnosis and management of critical illness-related corticosteroid insufficiency (CIRCI) in critically ill patients (Part I): Society of Critical Care Medicine (SCCM) and European Society of Intensive Care Medicine (ESICM) 2017.Intensive Care Med43(12):1751-1763, 2017. doi: 10.1007/s00134-017-4919-5 