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SEPTIC SHOCK. By Marian D. Williams RN BN CEN CFRN CCRN. SEPTIC SHOCK. Most common cause of death in non-cardiac ICU’s in the US Most cases are nosocomial Increased incidence due to advanced invasive technology Elderly are at greatest risk Mortality:40%-85%. SEPTIC SHOCK.
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SEPTIC SHOCK By Marian D. Williams RN BN CEN CFRN CCRN
SEPTIC SHOCK • Most common cause of death in non-cardiac ICU’s in the US • Most cases are nosocomial • Increased incidence due to advanced invasive technology • Elderly are at greatest risk • Mortality:40%-85%
SEPTIC SHOCK • 10th leading cause of death in the United States • 139% increase from 1979 - 1987
SEPTIC SHOCK • DEFINITIONS • Bacteremia • Presence of BACTERIA in the blood • Body’s defense systems effectively destroy bacteria • Septicemia • Presence of MICROBES in the blood associated with systemic infection
SEPTIC SHOCK • Sepsis • Systemic inflammatory response to infection. • Severe Sepsis/SIRS • Sepsis associated with evidence of one or more acute organ dysfunctions
SEPTIC SHOCK RISK FACTORS • Patient related • < 1 year of age • > 65 years of age • Debilitated • Malnourished • Chronic health problems
SEPTIC SHOCK RISK FACTORS • Treatment Related • Invasive lines and procedures • Surgical procedures • Treatment for burns or traumatic wounds • Immuno-suppression
Gram Negative Most cases E. COLI Most likely Klebsiella pneumoniae Enterobacter aerogenes Serratia marcescens Gram Positive Less common Staphylococcus aureus Viruses Fungi Rickettsiae Protozoans SEPTIC SHOCK CAUSATIVE MICROORGANISMS
SEPTIC SHOCK CAUSATIVE MICROORGANISMS • Gram Negative • Responsible for the majority of the cases
ENTRY SITES FOR SEPTIC SHOCK • Most common - GU Tract • GI Tract • Respiratory Tract • Skin
SEPTIC SHOCK PATHOGENESIS • Proinflammatory and procoagulation responses dominate and lead to uncontrolled inflammation and advanced coagulopathy
SEPTIC SHOCK PATHOGENESIS • Three known problems • Excess Coagulation • Exaggerated or malignant inflammation • Impaired fibrinolysis
SEPTIC SHOCK PATHOGENESIS • Balance of coagulation and fibrinolysis shifts toward increased coagulation via the extrinsic pathway
SEPTIC SHOCK PATHOGENESIS • In mice, microthrombi developed in the hepatic circulation within 5 minutes of injection of endotoxin
SEPTIC SHOCK PATHOGENESIS • Endotoxin is within the Gram Negative bacteria wall • Released into the blood during bacterial cell lysis
Macrophages Phagocytic cells found in the lung interstitium and alveoli, liver, sinuses etc. Activated by endotoxin to release cytokines Cytokines Tumor necrosis factor Major endogenous toxin * Interleukin-1 Interleukin-2 PATHOGENESIS OF SEPTIC SHOCK
Endotoxins activatesGRANULOCYTES Releases toxic mediators e.g. platelet activating factor, Oxygen derived free radicals Proteolytic enzymes Endotoxins activate arachidonic acid cascade Results in prostaglandin, leukotrienes, thromboxane A etc effecting smooth muscle PATHOGENESIS OF SEPTIC SHOCK
Thromboxane A2 and B2 Pulmonary vasoconstriction Mediate broncho-onstriction Potent platelet aggregator Prostaglandin E and Prostacyclin Potent vasodilator May be responsible for hypotension PATHOGENESIS OF SEPTIC SHOCK
Complement System Activated Produce microemboli Endothelial cell destruction Histamine Potent Vasodilator Released by mast cells Increases Capillary permeability (Fluid moves from vascular bed) PATHOGENESIS OF SEPTIC SHOCK
Myocardial Depressant factor (MDF) Released from pancreas Decreases contractility of the heart Coagulation system is activated Kinin System activated Bradykinin is released Vasodilation Increased capillary permeability PATHOGENESIS OF SEPTIC SHOCK
PATHOGENESIS OF SEPTIC SHOCK • MYOCARDIAL DEPRESSANT FACTOR • MAY ENHANCE DEVELOPMENT OF MICRO EMBOLI
HEMODYNAMIC ALTERATIONS OF SEPTIC SHOCK • Profound Vasodilation • Systemic vascular resistance is decreased • Blood Pressure falls • Veins dilate • Intravascular pooling in the venous capacitance system
HEMODYNAMIC ALTERATIONS OF SEPTIC SHOCK • Mal-distribution of blood flow • Some tissues under-perfused and some tissues are over-perfused • Excessive flow rates to areas of low metabolic demand limits O2 extraction • Therefore, difference in arterial and venous O2 content
HEMODYNAMIC ALTERATIONS IN SEPTIC SHOCK • Decreased ejection fraction • Definition: • Percent of diastolic volume that is ejected during systole
HEMODYNAMIC ALTERATIONS IN SEPTIC SHOCK • Decreased Ejection Fraction • Depressed myocardial contractility despite increased cardiac output • Right ventricular dysfunction is common – usually as a result of pulmonary hypertension and myocardial depression
HEMODYNAMIC ALTERATIONS IN SEPTIC SHOCK • Increased capillary permeability • Fluid movement out of the vascular beds and into the interstitial space • Generalized soft tissue edema results • Edema can interfere with tissue oxygenation and organ function
HEMODYNAMIC ALTERATIONS IN SEPTIC SHOCK • Microembolization • Results in sluggish blood flow • Decreased oxygen utilization therefore increased risk of D. I. C.
HYPERDYNAMIC PHASECLINICAL MANIFESTATIONS • BP Falls • Decreased SVR • Decreased venous return • Decreased sympathetic tone • Diastolic pressure falls
HYPERDYNAMIC PHASE -CLINICAL MANIFESTATIONS • Increased sympathetic tone • Widened pulse pressure • Heart rate increases in attempt to increase CO to compensate for decreased blood pressure
Impaired gas exchange Pulmonary blood congestion Pulmonary blood flow decreases Respiratory rate and depth increase Early respiratory alkalosis Crackles may be audible Interstitial pulmonary edema HYPERDYNAMIC PHASE -CLINICAL MANIFESTATIONS
HYPERDYNAMIC PHASE - CLINICAL MANIFESTATIONS • Impaired Gas Exchange • Pulmonary vascular resistance increases • Pulmonary congestion results
Febrile Possible associated chills Skin pink and warm Peripheral vasodilation LOC may be altered Cerebral ischemia HYPERDYNAMIC PHASE-CLINICAL MANIFESTATIONS
Decreased SVR Cardiac output high Cardiac Index high Decreased venous return Pulmonary artery pressures below normal PCWP below normal HEMODYNAMIC MANIFESTATIONS-HYPERDYNAMIC PHASE
HEMODYNAMIC MANIFESTATIONS-HYPERDYNAMIC PHASE • Maldistribution of blood flow • Oxygen consumption is decreased • SVO2 levels are above normal
HYPODYNAMIC PHASE-CLINICAL MANIFESTATIONS • Decreased cardiac output • Rapid, shallow respirations • Crackles and wheezes • Pulmonary congestion • Decreased Urinary output • Renal hypoperfusion • Lethargic
HYPODYNAMIC PHASE- CLINICAL MANIFESTATIONS • SNS Stimulation • Peripheral vasoconstriction • Narrowing pulse pressure • Cool, clammy skin • Increased afterload • Decreased contractility • PROFOUNDHYPOTENSION