Upon completion of the chapter, the reader will be able to:
Compare and contrast the definitions of syndromes related to sepsis.
Identify the pathogens associated with sepsis.
Discuss the pathophysiology of sepsis as it relates to pro- and anti-inflammatory mediators.
Identify patient symptoms as early or late sepsis and evaluate diagnostic and laboratory tests for patient treatment and monitoring.
Assess complications of sepsis and discuss their impact on patient outcomes.
Design desired treatment outcomes for septic patients.
Formulate a treatment and monitoring plan (pharmacologic and nonpharmacologic) for septic patients.
Evaluate patient response and devise alternative treatment regimens for nonresponding septic patients.
KEY CONCEPT Sepsis occurs across a continuum of physiologic stages in response to infection which manifests as systemic inflammation, coagulation, and tissue hypoperfusion, potentially leading to organ dysfunction known as severe sepsis.1 The American College of Chest Physicians and the Society of Critical Care Medicine have defined the nomenclature to standardize sepsis terminology. (Table 82–1).2,3 Physiologic parameters categorize patients as having systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, or septic shock.2
Table 82–1Diagnostic Criteria for Sepsis, Severe Sepsis, and Septic Shock |Favorite Table|Download (.pdf) Table 82–1Diagnostic Criteria for Sepsis, Severe Sepsis, and Septic Shock
|Sepsis (documented or suspected infection plus ≥ 1 of the following) |
|General variables |
| Hyperthermia (core temperature > 38.3°C) |
| Hypothermia (core temperature < 36°C) |
| Tachycardia (heart rate > 90 beats/min) |
| Tachypnea |
| Altered mental status |
| Substantial edema or positive fluid balance (> 20 mL/kg of body weight over 24 hours) |
| Hyperglycemia (plasma glucose > 120 mg/dL [6.7 mmol/L]) in absence of diabetes |
|Inflammatory variables |
| Leukocytosis (white blood cell count > 12,000/mm3 [12 × 109/L]) |
| Leukopenia (white blood cell count < 4000/mm3 [4 × 109/L]) |
| Normal white blood cell count with > 10% (0.10) immature forms (bands) |
| Elevated plasma C-reactive protein |
| Elevated plasma procalcitonin |
|Hemodynamic variables |
| Arterial hypotension (systolic pressure < 90 mm Hg; mean arterial pressure < 70 mm Hg (9.3 kPa); or decrease in systolic pressure of > 40 mm Hg) |
| Organ dysfunction variables |
| Arterial hypoxemia (Pao2/Fio2 < 300 mm Hg [39.9 kPa]) |
| Acute oliguria (urine output < 0.5 mL/kg/hour or 45 mL/hour for at least 2 hours) |
| Increase in serum creatinine level of > 0.5 mg/dL (> 44 μmol/L) |
| Coagulation abnormalities (INR > 1.5; or aPTT > 60 seconds) |
| Paralytic ileus (absence of bowel sounds) |
| Thrombocytopenia (platelet count < 100,000/mm3 [100 × 109/L]) |
| Hyperbilirubinemia (plasma total bilirubin > 4 mg/dL [68.4 μmol/L]) |
|Tissue-perfusion variables |
| Hyperlactatemia (lactate > 1 mmol/L) |
| Decreased capillary refill or mottling |
|Severe sepsis (sepsis plus organ dysfunction) |
|Septic shock (sepsis plus either hypotension [refractory to fluid resuscitation] or hyperlactatemia) |
EPIDEMIOLOGY AND ETIOLOGY
Sepsis is the leading cause of morbidity and mortality for critically ill patients and the tenth leading cause of death overall.4,5...