Alterations in Perfusion - Shock (PDF)

ALTERATIO NS IN N467 PERFUSION (SHOCK) PATHOPHYSIOLOGY OF SHOCK  Decreased tissue perfusion  Cellular dysfunction reversible at first  Compensatory mechanisms: vasoconstriction  Can progress to MODS (multiple organ dysfunction syndrome) Ho...

ALTERATIO NS IN N467 PERFUSION (SHOCK) PATHOPHYSIOLOGY OF SHOCK  Decreased tissue perfusion  Cellular dysfunction reversible at first  Compensatory mechanisms: vasoconstriction  Can progress to MODS (multiple organ dysfunction syndrome) Homeostasis Injury/infection Compensation Decompensation Compensated shock: reversible Decompensated shock: reversible Irreversible shock Death 1ST STAGE-INITIAL STAGE OF SHOCK  Compensatory mechanisms are effective  S&S difficult to detect  slight increase in heart rate,  Slight increase in RR  MAP 5-10 mmHg below baseline  Cellular level – lactic acid produced due to anaerobic metabolism  Body is switching from Aerobic-Anerobic   Tissue hypoxia in non-vital organs  CV Compensatory mechanisms not enough  Kidney & chemical mechanisms kick in COMPENSAT  Renin, ADH, aldosterone, epinephrine ORY STAGE and norepinephrine OF SHOCK  Symptoms remain subtle  Acidosis & hyperkalemia  Increased HR and RR  Rising diastolic BP and narrowing pulse pressure  MAP 10-15 mmHg below baseline 2ND STAGE -PROGRESSIVE OR INTERMEDIATE STAGE OF SHOCK  Compensatory mechanisms not effective  Hypoxia of vital organs - Anoxia & ischemia of less vital organs  Symptoms more pronounced  Sustained decrease in MAP>20 mmHg  Rapid, weak pulse  Low BP  Pallor to cyanosis of oral mucous membranes and nail beds  Acidosis progresses, Increased lactic acid levels, Increased serum potassium SYSTEM FAILURES  Cardiovascular dysfunction  Central Nervous System dysfunction  Hematologic Dysfunction  Pulmonary Dysfunction  Renal Dysfunction  Gastrointestinal Dysfunction 3RD STAGE-REFRACTORY OR IRREVERSIBLE STAGE OF SHOCK  Massive release of toxic metabolites and enzymes  Trigger formation of micro-thrombi  Extensive cell damage -  Not treatable  Regardless of etiologic factors, death occurs from an imbalance of oxygen supply and demand! MULTIPLE ORGAN DYSFUNCTION SYNDROME (MODS) Multiple organ dysfunction syndrome (MODS): Presence of progressive physiologic dysfunction in 2 or more distinct organ systems TYPES OF SHOCK  Hypovolemic=lack of blood volume  Cardiogenic  Pump Failure loss of contractile force inadequate CO inadequate tissue perfusion  Obstructive=obstruction of blood flow  Distributive=increased vascular volume  Neurogenic  Anaphylactic  Septic OBSTRUCTIVE SHOCK Some obstruction to blood flow  Pulmonary embolism  Cardiac tamponade  Pericarditis  Pulmonary hypertension  Tension pneumothorax  Tension hemothorax  Ruptured Aneurysms  Can result in both obstructive and hypovolemic shock HYPOVOLEMIC SHOCK Fluid depletion  Hemorrhage:  GI bleed, trauma, surgery  Fluid shifts  burns  Dehydration:  vomiting, diarrhea, DKA, DI, heat stroke  Etiology:  Absolute vs. Relative HYPOVOLEMIC: NURSING ASSESSMENT  First stage - initial  Approx. 4, give 30 ml/kg bolus.  Needs to be completed as soon as possible.  80 KG patient would need to receive a 2400 ml bolus. SEPTIC SHOCK: MANAGEMENT  Drug Therapy  Vasoconstricting agents: only if hydration not effective  Norepinephrine (Levophed)  Dopamine (Intropin)  Dobutamine (Dobutrex) increases contractility SEPTIC SHOCK: MANAGEMENT  Constant monitoring!!!  Vital signs – at least every 15 minutes, usually more often  LOC  Urinary Output HEMODYNAMIC PROFILING  Preload  CVP – right side of heart  PAWP – left side of heart  Contractility  RVSWI – right side of heart  LVSWI – left side of heart  Afterload  Pulmonary Vascular Resistance (PVR)  Systemic Vascular Resistance (SVR) HEMODYNAMIC NORMAL VALUES  RAP/CVP(Preload)  2-8 mmHg  RVP  20-30 mmHg systolic/ 2-8 mmHg diastolic  PAP  20-30 mmHg systolic / 8-15 mmHg diastolic  PCWP  8-12 mmHg  LVSWI (contractility)  50 – 62 g-m/m2  RVSWI(contractility)  7.9 –9.7 g-m/m2  C.O.  4-8 L/min  CI  2.5-4L/min  PVR (afterload)  50-250 dynes/sec/cm-5  SVR  800-1500 dynes/sec/cm-5 HEMODY NAMIC PDF PULMONARY ARTERY PRESSURE ABNORMALITIES Increased Systolic:  PE  COPD  ARDS  Pulmonary Hypertension Increased Diastolic:  Lung Disease  Fluid volume overload  Left heart dysfunction Decreased Systolic and Diastolic:  Hypovolemia