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🌱 來自: Huppert’s Notes
SIRS, Sepsis, Severe Sepsis, and Septic Shock🚧 施工中
SIRS, Sepsis, Severe Sepsis, and Septic Shock
• Introduction:
- Sepsis exists on a clinical spectrum of illness severity, with septic shock being the most severe
- Two major clinical approaches to a patient with suspected sepsis:
• qSOFA is an assessment score used to detect early sepsis. It is easily performed at the bedside and is best suited for triage and early assessments, as it is well validated in patients outside of the ICU.
• Older definition using the Sepsis-2 guidelines remains the most widely used and preferred approach for grading the severity of sepsis in the ICU.
- Note on Sepsis-3 guidelines (2016): SIRS and severe sepsis were dropped from these guidelines. Instead, Sepsis-3 defines sepsis as a rise in SOFA score of ≥2 points and septic shock as hypotension requiring vasopressors and an elevated lactate.
• Sepsis II definitions:
- Systemic inflammatory response syndrome (SIRS): Must meet at least two of four criteria
• Temp <36°C or >38°C
• HR >90 bpm
• RR >20 breaths/min or PaCO2 <32 mmHg
• WBC >12K or <4K or >10% bands
- Sepsis: SIRS + suspected infection
- Severe sepsis: Sepsis + acute organ dysfunction
• Acute organ dysfunction
- Hypotension (SBP <90 mmHg or MAP <70 mmHg)
- Hypoxemia (P/F <300)
- Oliguria (UOP <0.5 cc/kg/hr)
- Renal injury (Cr increase >0.5)
- Coagulopathy (INR >1.5)
- Thrombocytopenia (Plt <100K)
- Hyperbilirubinemia (Total bilirubin >4)
- Lactate >2
- New altered mental status
- Septic shock: Hypotension due to sepsis despite adequate fluid resuscitation (classically 30 cc/kg), as well as signs of hypoperfusion
• Sequential Organ Failure Assessment (SOFA):
- Alternative scoring system that can be used to predict the clinical outcome of critically ill patients and used in the Sepsis-3 guidelines. Takes into account Glasgow Coma Score (GCS), renal function, liver function, coagulopathy, and respiratory status (see Table 3.3)
TABLE 3.3 • Sequential Organ Failure Assessment (SOFA) Score
- qSOFA (Quick SOFA) is a bedside assessment for early detection of suspected sepsis
• Criteria: 1 point for each
- RR ≥22 breaths/min
- Altered mentation
- SBP ≤100 mmHg
• Positive score is ≥2
• Implications
- Positive score should prompt evaluation for end-organ dysfunction and calculation of full SOFA score
- Scores of 2–3 associated with higher in-hospital mortality
- Easily identified at the bedside and can be repeated as clinical changes occur
- Conflicting data on use in the ICU, may be more useful outside the ICU but research is ongoing
- See Table 3.4 for types of shock and associated features
TABLE 3.4 • Types of Shock
• Pathophysiology:
- Infection causes proinflammatory cytokine storm (TNF-a, IL-1), “malignant intravascular inflammation”
- In infection, microorganism factors such as bacterial cell wall components (LPS) and bacterial products (toxins) may cause inflammatory reaction
- Inflammation leads to low systemic vascular resistance (SVR), fever, leukocytosis
- Cellular injury occurs, which can lead to further organ dysfunction:
• Tissue ischemia from metabolic autoregulatory failure and hypoperfusion
• Mitochondrial dysfunction and cell death
• Management:
- Antibiotics and infection control:
• Start broad, empiric IV antibiotics within 1 hour of recognizing severe sepsis or septic shock
- Consider healthcare exposure, immune status, prior culture data, risk of multi-drug resistant (MDR) organisms
- See hospital-specific guidelines for empiric antibiotic choices based on local patterns of antimicrobial resistance
• Special considerations:
- If considering bacterial meningitis, should also co-administer steroids
- Neutropenic fever empiric coverage includes anti-pseudomonal beta-lactam +/− MRSA coverage depending on the clinical situation
• Collect blood cultures (×2) and urine cultures BEFORE starting antibiotics, if possible
• Attempt to determine a source of infection based on history, physical exam, labs, cultures, and imaging. Consider additional imaging if needed to identify an occult source of infection
- Intravenous fluid resuscitation:
• Crystalloids are the initial preferred resuscitation agent
- Usual resuscitation with 30 cc/kg of crystalloid
- Normal saline is often first crystalloid used for hypovolemia and resuscitation; however, large volumes can cause hyperchloremic metabolic acidosis
- Balanced solutions (lactated Ringer’s [LR] or Plasma-Lyte) are isotonic solutions with less chloride than normal saline (NS) and are thus more physiologic and often used for larger volumes of infusion. Data also suggest a mortality benefit when used over NS for critically ill patients (SMART trial, New Engl J Med 2018).
• Resuscitation goals:
- MAP >65 mmHg for most patients
- Maintain adequate RV filling pressure
• Classically, guidelines had targeted CVP goals; however, CVP changes under a variety of patient conditions, such as if they are intubated (positive pressure ventilation) or not (negative pressure ventilation) as well as if RV dysfunction is present
- Urine output >0.5 cc/kg/hr
• Can use lactate clearance to help guide resuscitation and risk stratification
- Higher lactate correlates with higher mortality
- Trend and remeasure lactate during resuscitation
- Vasopressors:
• If still hypotensive despite adequate fluid resuscitation, add vasopressors
• Norepinephrine is the first-line vasopressor for septic shock
• Be aware of the patient’s cardiac status and renal function when giving IVF, monitor for hypoxia with aggressive fluid resuscitation