SHOCK DEFINITION Inadequate delivery of oxygen and substrates to meet the metabolic needs of the tissues. Prompt diagnosis is essential, as the prognosis depend on severity and duration. Pathophysiology… Types of shock Hypovolaemic Cardiogenic Septic Anaphylactic Vasovagal Neurogenic Hypovolaemic shock Causes Hemorrhage Non haemorrhagic Burns Diarrhea Vomiting Intestinal obstruction Peritonitis Urinary loss(DM) Hypovolaemic shock 4 classes Depends on % of total blood volume loss Associated symptoms & signs Classes of hypovolaemic shock… % Loss of Pulse Systolic Pulse p Capillary Respiration CNS Urine Circulating rate P refill output blood volume <15% Normal Normal Normal Normal Normal Normal >30ml/hr 15 – 30% >100 Normal Reduced Delayed Mild Anxious 20 – tachynpnea 30ml/hr 30 – 40% >120 Reduced Reduced Delayed Marked Confused 10 – Weak tachypnea 20ml/hr >40% >140 Very Markedly Absent Marked Lethargic <10ml/hr Thready low reduced tachypnea Management… ABC approach High flow O2 via face mask. 2 large bore iv cannulae. Take blood for FBC, SE, grouping & cross matching. Crystalloids or colloids for initial resuscitation. Identify site of bleeding, and take necessary actions to arrest it. Management cont…. - Inform the blood bank, OT, Anesthetist - Blood O-ve - for very urgent cases Group specific - for urgent cases Fully cross matched - if there is time - All IV fluids should properly warm before giving to the patient Because hypothermia (<35oC) – high motility Aggressive fluid resuscitation- increased bleeding Anaphylactic shock Anaphylactic shock - Ig E mediated Type I hypersensitivity reaction to an antigen - Release of histamine & serotonin from mast cells & basophils - Common causative agents - Drugs Radio –contrast media Blood products Presentation - Cardiovascular collapse - Erythema - Bronchospasm - Angioedema - Rash - Urticaria Anaphylactic shock- management Immediate - Stop administration of any potential triggering agent. - Check ABC - Call for help - Maintain the airway & give 100% O2 - Lay the patient flat & legs up - Adrenaline (1:1000) 0.5 - 1ml IM, repeat every 5- 10min - IV fluids (crystalloids or colloids) Subsequent management - Hydrocortisone – 100mg - 300mg iv - Antihistamines – chlorpheniramine 10mg iv - Check ABG - consider NaHCO3 if acidotic - Consider bronchodilators if bronchospasms Septic shock Septic shock - Severe sepsis & arterial hypotension refractory to fluid resuscitation. - Due to infection mainly with gram negative organisms. Clinical features Fever with chills and rigors or hypothermia Hypotension Tachypnoea, tachycardia Nausea and vomiting Vasodilatation, warm peripheries Bounding pulse With a history suggestive of infection Diagnosis Full Blood Count with Differential count Platelet count Sepsis Screen ◦ Cultures - blood, urine, sputum – prior to antibiotics Basic chemistry – serum bilirubin, serum lactate, renal function tests Coagulation screen Management… Fluid Resuscitation Crystalloids or colloids Target CVP - >8mmHg Vasopressors Maintain MAP >65 mmHg Noradrenalin Add Dobutamine if cardiac dysfunction Management cont… Antibiotics ◦ Start with broad spectrum antibiotics empirically, adjust according to sensitivity. ◦ Duration 7-10 days Septic shock management cont… Low dose Steroids ◦ Hypotension respond poorly to fluids/ Vasopressors Hydrocortisone 200 - 300mg/day x 7d Blood ◦ IF HB% <7g/dl Cardiogenic shock Cardiogenic shock Causes ◦ MI ◦ Arrhythmia ◦ Valvular heart disease ◦ Tension pneumothorax ◦ Cardiac tamponade ◦ Cardiac contusion ◦ Cardiomyopathies ◦ Pulmonary Embolism Cardiogenic shock management Management depends on the cause General measures are Give high flow O2 Put patient on cardiac monitoring An ECG Send blood for ABG FBC Cardiac enzymes BU & SE Urgent echocardiogram Chest x ray Catheterize the pt and monitor UOP Management cont… Further management depends on the cause Arrhythmias - Anti arrhythmatics MI - GTN, Heparin or Streptokinase, Aspirin. Fluid overload - Diuretics (Frusemide 40mg iv) Tension pneumothorax - Needle thoracotomy, IC tubes Cardiac tamponade - Emergency pericardiocentesis Emergency thoracotomy Aggressive fluid resuscitation Shock management…other measures DVT prophylaxis - LMWH - Mechanical prophylaxis devices Stress ulcer prophylaxis - H2 receptor blockers or proton pump inhibitors Renal replacement therapy - Intermittent haemodialysis - Continuous veno-venous haemofiltration Neurogenic Shock Traumatic or pharmacological blockage of the sympathetic nervous system causes dilation of arterioles and capacitance veins leading to relative hypovolaemia and hypotension Vasovagal shock Pooling of blood in larger vascular reservoirs(limb muscles) and dilation of splanchnic arterioles lead reduced venous return to heart causing low cardiac output.