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Systemic Inflammatory Response Syndrome and Multiple Organ Dysfunction Syndrome 1 3 main types of shock • A "shock combo shituation" is far worse than shock of a single type. • Occurs when shock is severe. • (For instance, a patient with severe cardiogenic shock and systemic ischemia can have activation of the inflammatory system (S.I.R.S.). "cytokine storm" • In severe shock the microcirculation changes dramatically. • Those changes are mainly due to a induced by extremely severe tissue ischemia or, directly, by a pathogen: – (1) the endothelium is activated (vasodilates, becomes pro-coagulant, expresses adhesion molecules), – (2) monocytes are activated (and discharge numerous cytokines), – (3) white blood cells obstruct some capillaries – (4) disseminated intra-vascular coagulation and platelet aggregation plug microcirculation as well. When there is so much deterioration to the microcirculation, perfusion to organs worsens rapidly....and, as a consequence, systemic shock also worsens extremely rapidly... vicious cycles fuel and exacerbate the downhill course • When tissue hypoxia starts to create multi organ failure/dysfunction, each organ system suffers and often influences negatively the state of shock . • Many vicious cycles are at play in decompensated shock stages. • If treatment of the shock's cause is not successful or delayed, "Cytokine storm" is in full bloom! ...and ... it is a catastrophic, and often terminal SIRS • Simply….a severe systemic response to a critical incident • An abnormal host response to a variety of insults • Characterized by generalized inflammation in organs remote from the initial insult • Normally, inflammatory process is contained within confined environment • If not, a wide spread systemic inflammatory response occurs that is deleterious to organ function 5 What is S.I.R.S. Systemic inflammatory response syndrome (SIRS) is a general inflammatory response to various causes. It is considered to be due to cytokines ("cytokine storm") Clinical Manifestations of SIRS • Temperature greater than 100.4° F (38°C) or less than 97°F (36° C) • Heart rate greater than 90 beats per minute • Respiratory rate greater than 20 breaths per minute or PaCO2 less than 32 mmHg • White Blood Cell Count greater than 12,000 cells/ul or less than 4,000 cell/ul or greater than 10% immature (band) neutrophils 8 Clinical Manifestations of SIRS • May demonstrate – Hypotension – Confusion – Hyperglycemia – Thrombocytopenia – Mild signs and symptoms to circulatory collapse 9 Organ Manifestations • Cardiovascular – Skin warm and flushed – Widened pulse pressure – Cardiac output is increased but SVR is decreased – Eventually C.O. declines exacerbating hypoperfusion Clinical Evidence of Organ Dysfunction • Cardiovascular Failure – HR<55beats/min – MAP<50mmHg or systolic blood pressure <mmHg – Ventricular tachycardia or fibrillation – Cardiac Index<2.0L/min/m2 – Serum pH<7.25 with a PaCO2 <50mmHg 11 Organ Manifestations • Pulmonary – Hypoxemia may be masked by hyperventilation – Respiratory alkalosis – Pulmonary edema – Respiratory failure – Bronchoconstriction – ARDS Clinical Evidence of Organ Dysfunction • Respiratory Failure – Severe dyspnea – RR<6 or >50 breaths/min – Chest X-ray with decreased lung volumes and bilateral diffuse patchy infiltrates – PaCO2 >50mmHg – Crackles, wheezes – PaO2/FIO2 <200 – Ventilatory dependence>72hr 13 Clinical Evidence of Organ Dysfunction • Central Nervous System Failure – Glasgow Coma Scale< (in absence of sedation) – Hypothermia or hyperthermia – Cardiovascular failure – Respiratory depression • CNS – – – – – – – – Altered mental status Confusion Irritability Agitation Disorientation Lethargy Seizures Coma 14 Clinical Evidence of Organ Dysfunction • Gastrointestinal Failure – Mucosal erosion on endoscopy – Perforation – Upper or lower GI bleeding – Diarrhea – Paralytic ileus • GI – Impaired motility – Increased SGOT – Increased SGPT – Hyperbilirubinemia – Hepatic necrosis – Hypoglycemia 15 Clinical Evidence of Organ Dysfunction • Hepatic Failure – Presence of both of the following: • Serum bilirubin>6mg/dl (102.6 umol/L) • Prothrombin time>4sec over control in the absence of systemic anticoagulation • Pancreatic Failure – Elevated serum lipase and amylase – Elevated serum glucose (often resistant to insulin administration) 16 Clinical Evidence of Organ Dysfunction • Blood – Hypoprothrombinemia – Increased or decreased WBCs – Increased PT/PTT – Increased or decreased platelets – Anemia • Hematologic Failure – White blood cell count<1000/ul (1x103/L) – Platelets< 20,000/ul (20X109/L) – Hematocrit <20% (.20) – Bleeding studies prolonged 17 Treatment •Supportive •Medical •Surgical Nursing and Collaborative Management • • • • • Prevention and treatment of infection Maintenance of tissue oxygenation Nutritional and metabolic needs Support of failing organs Research in SIRS and MODS 19 Supportive Therapy • • • • • Volume replacement Positive inotropes Vasopressors Ventilation (PS or PEEP) Nutritional Support – Iso-osmotic feedings – TPN – PPN – Immune Modulatory foods such Arginine, Glutamine and fish oils Clinical Manifestations of SIRS • • • • • Initially have mild restlessness or confusion Hyperthermia Tachycardia Some increase in fluid requirements Tachypnea with mild respiratory alkalosis 21 Clinical Manifestations of SIRS • Oliguria with reduced responsiveness to diuretics • Abdominal distention • Hyperglycemia or increased glucose requirements • Patient appears acutely sick and unstable 22 Clinical Manifestations of SIRS • In advanced SIRS or MODS – – – – – – – – – Unstable and appears close to death Unresponsive Vasopressors and inotropic agents needed to maintain BP Grossly edematous Hypercapneic despite aggressive ventilation Anuric Liver and bili levels rise Lactic acidosis worsens Coagulopathy becomes impossible to correct 23 Clinical Evidence of Organ Dysfunction • Renal – Oliguria <500 ml/day – Urine Output<0.5 ml/kg/hr – BUN>100mg/dl (35.7mmol/L) – Serum creatinine>3.5mg/dl (309umol/L) – Metabolic Acidosis 24 Multiple Organ Dysfunction Syndrome (MODS) • End stage of a variety of injuries that terminate in severe, generalized inflammation • First recognized in the mid-1970s when advances in in resuscitation and support technologies allowed many individuals to survive life-threatening illness or trauma only to die from complications of their disease. MODS • The presence of altered organ function in an acutely ill patient such that homeostasis cannot be maintained without intervention. • Primary MODS is the direct result of a well-defined insult in which organ dysfunction occurs early and can be directly attributable to the insult itself. • Secondary MODS develops as a consequence of a host response and is identified within the context of SIRS. • The inflammatory response of the body to toxins and other components of microorganisms causes the clinical manifestations of sepsis. MODS • Results from an uncontrolled inflammatory response to a severe illness or injury • Initiated by severe injury or disease process that activates a massive inflammatory response by the host • Sepsis and septic shock are most common cause • Organ dysfunction can progress to organ failure and death 27 MODS • Homeostasis cannot be maintained without intervention • Well-defined insult in which organ dysfunction occurs early and can be directly attributable to the insult itself • Secondary MODS develops as a consequence of a host response and is identified within the context of SIRS 28 MODS • Triggers – Severe trauma – Major surgery – Burns – Circulatory shock – Acute pancreatitis – Acute renal failure – ARDS – Persistent inflammatory foci – Necrotic tissue 29 MODS • People at greatest risk – Age >65 years – Baseline organ dysfunction (renal insufficiency) – Bowel infarction – Coma on admission – Inadequate, delayed resuscitation – Malnutrition – Multiple blood transfusions (>6 units/12 hour) – Persistent infectious focus – Preexisting chronic disease (diabetes, cancer) – Presence of hematoma – Significant tissue injury – Steroids 30 Pathophysiology of MODS • Progressive organ dysfunction • excessive inflammatory reaction in organs distant from site of original injury • Host response is responsible • Self-perpetuating inflammation • Releases barrage of mediators, when stimulated by the delayed postinjury insult • These mediators damage the endothelium throughout the body 31 Pathophysiology of MODS • Tachycardia, hypermetabolism, and increased oxygen consumption, Cortisol, insulin, human growth hormone, ADH, and endorphin levels are increased • Contributing to extreme catabolic state • Endorphins vasodilate, decreasing SVR 32 Pathophysiology of MODS • SNS stimulated and amplified by factors including pain, anxiety, psychosis, and hyperthermia • Major plasma cascades are activated • Stimulating release of histamine from mast cells • They have strong chemotactic properties, C5a, causes adhesion • Activation and degranulation of neutrophils • Because of endothelial cell damage and the release of mediators starting at least 4 different cascade of events involving mediator chains 33 Pathophysiology of MODS • Complement is exaggerated-inflammatory response • Activation of kinin system activates bradykinin-vasodilator • Coagulation mechanism activated-microvascular circulation impaired-organ ischemia • Fibrolytic mechanism activated • Development of DIC • Hyperinflammatory and hypercoagulant state contributes to vasodilation, vasopermeability, cardiovascular instability, endothelial damage, and clotting abnormalities • Once cytokines and other mediators have been released and the plasma enzyme cascades have been activated 34 • A massive systemic inflammatory response develops Pathophysiology of MODS • TNF –potent metabolic effects – Fever – Anorexia – Hyperglycemia – Hypermetabolism – Weight loss and muscle wasting – Myocardial depression – Activates neutrophils 35 Pathophysiology of MODS • Reperfusion injury – Re-establishment of blood flow after a period of ischemia – During ischemic episodes, energy stores and ATP are depleted and the enzyme xanthine dehydrogenase is converted to xanthine oxidase which attack the already damaged tissues – Although reperfusion is necessary to restore oxygen supply to ischemic organs, it can increase the extent of injury – Because of supply-dependent oxygen consumption and reperfusion injury, tissues become increasingly hypoxic – Result is cellular acidosis, impaired cellular function, and ultimately multiple organ failure 36 Clinical Manifestations of MODS • Pulmonary – Adult respiratory distress syndrome – Pattern of respiratory failure • • • • • Dyspnea Patchy infiltrates Refractory hypoxemia Respiratory acidosis Abnormal O2 indices – Pulmonary hypertension 37 Clinical Manifestations of MODS • Gastrointestinal – Abnormal distention and ascites – Intolerance to enteral feedings – Paralytic ileus – Upper and lower gastrointestinal bleeding – Diarrhea – Ischemic colitis – Mucosal ulceration – Decreased bowel sounds – Bacterial overgrowth in stool 38 Clinical Manifestations of MODS • Liver – Increased serum bilirubin level – Increased liver enzyme levels • AST, ALT, LDH – Increased serum ammonia level – Decreased serum transferrin level – Jaundice – hepatomegaly 39 Clinical Manifestations of MODS • Gallbladder – Right upper quadrant tenderness or pain – Abdominal distention – Unexplained fever – Decreased bowel sounds 40 Clinical Manifestations of MODS • Hypermetabolism – Decreased lean body mass – Muscle wasting – Severe weight loss – Negative nitrogen balance – Hyperglycemia – Hypertriglyceridema – Increased serum lactate levels – Decreased serum albumin, serum transferrin, prealbumin, retinol-binding protein 41 Clinical Manifestations of MODS • Renal – Increased serum creatinine level and Blood urea nitrogen – Oliguria, anuria, or polyuria consistent with prerenal azotemia or acute tubular necrosis – Urinary indices consistent with prerenal azotemia or acute tubular necrosis 42 Clinical Manifestations of MODS • Cardiovascular –Hyperdynamic • Decreased PAOP • Decreased SVR • Decreased RAP • Decreased LVSWI • Increased oxygen consumption • Increased C.O., CI, and HR 43 Clinical Manifestations of MODS • Cardiovascular –Hypodynamic • Increased SVR • Increased RAP • Increased LVSWI • Decreased oxygen delivery and consumption • Decreased C.O. and CI 44 Clinical Manifestations of MODS • Central Nervous System – Lethargy – Altered LOC – Fever – Hepatic encephalopathy 45 Clinical Manifestations of MODS • Coagulation and Hematologic – Thrombocytopenia – Disseminated Intravascular Coagulation • Immune – Infection – Decreased lymphocyte count – energy 46 MODS Evaluation and Treatment • No specific therapy • Lots of experimentation • Therapeutic management of MODS is prevention and support • Supportive measures initiated ASAP – Identifies where the person is on the continuum of illness 47 MODS Evaluation and Treatment • Severity of illness scoring system – Acute Physiology And Chronic Health Evaluation II and III (APACHE II and III) – Assesses prognosis in large group, not individually, and therefore not well adapted for clinical decision making – More useful in the research studies – Individual variables to describe relative risks of individuals 48 MODS Evaluation and Treatment • Initial source of inflammation must be eliminated or controlled • Second insult must be eliminated • Remove any potential site of infection by debriding necrotic tissue, draining abscesses, reducing number of invasive procedures performed, removing hematomas • Nosocomial infection rates of 15% to 25% have been reported in critically ill individuals • Early reduction of long-bone fractures and surgical repair of injured tissues 49 MODS Evaluation and Treatment • Goals of therapy – Control infection and inflammation • Monoclonal antibiotics-modulate or inhibit the immune and inflammatory responses • Anti-inflammatories • Antioxidants and free radials scavengers 50 MODS Evaluation and Treatment • Goals of therapy – Provide adequate tissue oxygenation • Oxygen saturation must be above 90% at all times • Hemoglobin levels should be kept above 10 to 12g/dl • Mechanical ventilation with high oxygen concentrations and PEEP 51 MODS Evaluation and Treatment • Goals of therapy – Restore intravascular volume • Aggressive fluid resuscitation – Support the function of individual organs • “Need to feed” (keeps gut alive, hypermetabolism, catabolism) • Dialysis • Inotropic drugs 52