Unit IV – Problem 9 – Clinical Prepared by: Ali Jassim Alhashli Kingdom of Bahrain Arabian Gulf University College of Medicine and Medical Sciences Unit IV – Problem 9 – Clinical Shock Prepared by: Ali Jassim Alhashli Based on: Kaplan Step 2 CK Internal Medicine

Shock and Resuscitation What is shock? Oxygen delivery to vital organs and tissues is inadequate to meet the metabolic demands (hypoperfusion). This results in anaerobic metabolism and lactic acidosis. There are 3 phases of shock: Compensated shock (early stage): Compensatory mechanisms will be activated insuring adequate perfusion to organs: Sympathetic nervous system. Renin-angiotensin-aldosterone system. Endocrine response. Presentation: Tachycardia, tachypnea, NORMAL BLOOD PRESSURE and cool pale skin. Decompensated shock: In which compensatory mechanisms fail to maintain adequate perfusion to organs. Presentation (global tissue hypoxia to organs): CNS: altered mental status. Heart: myocardial depression. Lungs: hypoxia and ARDS. Renal: decreased urine output. GI: bowel ischemia. Irreversible shock (late stage): There is massive cell damage with failure of organs. Shock cannot be reversed with any medical intervention (body is not responding). Slow shallow breathing, LOW BLOOD PRESSURE, patient is comatose, cold cyanotic skin and there is systemic failure (renal, hepatic, ARDS, DIC). Shock and Resuscitation

Shock and Resuscitation What are the types of shock? Hypovolemic: acute fluid loss resulting in loss of circulatory volume Hemorrhagic: GI bleeding, trauma or hemoptysis. Classification of hemorrhagic shock: Class-I: increased respiratory rate (14-20 breaths/minute) and patient is slightly anxious. Class-II: pulse < 100 beats/minute. Class-III: low Bp. Class-IV: patient is confused and lethargic. Non-hemorhagic (due to fluid loss): vomiting, diarrhea or burns. Cardiogenic: impaired heart pump function: Myocardial Infarction (MI). Valvular heart disease. Arrhythmias (e.g. atrial fibrillation, heart block or ventricular tachycardia). Distributive: there is pathologic peripheral vasodilation Septic. Anaphylactic. Neurogenic: there is disruption of sympathetic regulation of vascular tone. Patient will have bradycardia because there is no sympathetic input to the hear to increase heart rate and contractility. Obstructive: Pulmonary embolism. Tension pneumothorax. Cardiac temponade. Shock and Resuscitation

Shock and Resuscitation

Shock and Resuscitation

Shock and Resuscitation

Shock and Resuscitation

Shock and Resuscitation Septic shock: In sepsis, there is an infection which causes an inflammatory response → that will become exaggerated →and causes damage to different organs of the body. There will be vasodilation (this explains why extremities are WARM in septic shock), capillary leak and activation of coagulation system (that usually results in DIC). How to diagnose sepsis? ≥ 2 SIRS criteria + an evidence of infection (most commonly from respiratory or urinary tracts) WBCs < 12,000 cells/mm3 or > 4000 cells/mm3 Hear rate < 90 beats/minute. Respiratory rate < 20 breaths/minute or PaCO2 > 32 mmHg. Temperature < 38 C or > 36 C How to diagnose septic shock? Sepsis + low Bp Diagnostic assessment for patient with septic shock: Vital signs: blood pressure, pulse, respiratory rate and temperature. CBC and differentials. ABG. Coagulation profile: PT, PTT, fibrinogen and D-dimer. Serum electrolytes. LFTs and RFTs. Blood cultures. Urinalysis and urine culture. Shock and Resuscitation

Shock and Resuscitation Septic shock (continued): Management: ABC: Determine the need for intubation and mechanical ventilation (which decreases the work of breathing and improves survival). Fluid therapy: Type of fluid: crystalloid (e.g. normal saline or ringer lactate) or colloid (e.g. albumin and synthetic starch in which less resuscitation volume is needed). Amount of fluid: 4-8 L of crystelloid preferred to be administered as a bolus instead of an infusion. When to stop fluids? MAP ≥ 60 mmHg, urine output ≥ 0.5 ml/kg/hour, decreasing serum lactate and central venous pressure = 8-12 mmHg. If patient is not responding to fluid therapy, consider administrating vasoactive agents such as: epinephrine, dopamine or vasopressin. Control infection by starting broad-spectrum antibiotics after obtaining blood samples for culture. Shock and Resuscitation

Shock and Resuscitation