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TRAUMATIC SHOCK Do Ngoc Son MD., PhD. Emergency Department 1 Bach Mai Hospital, Hanoi Objectives • Definition of traumatic shock • Recognition of shock stages and severity • Management of shock according to stages and severity 2 DEFINITION AND PATHOPHISIOLOGY OF SHOCK 3 DEFINITION OF SHOCK • Inadequate organ perfusion and tissue oxygenation. • Circulatory system failed to meet the metabolic demand of the body 4 HUMAN CIRCULATORY SYSTEM 5 ARTERIAL BLOOD PRESSURE Preload Cardiac output Blood pressure Stroke volume Heart rate Cardiac contractility Afterload Systemic vascular resistance 6 BOOD PRESSURE REGULATION (ROLE OF NEURO-ENDOCRINE SYSTEM) • Pressure receptors located at the aortic arch and carotids • Sympathoadrenal axis regulate the release of catecholamine • Renin-angiotensin-aldosteron system blood vessel tone and urine secretion 7 8 VOLUME STATUS BLOOD VOLUME 8% 25% ECF ICF Intravascular volume 67% 9 PHYSIOLOGICAL RESPONSES DURING SHOCK • In normal condition, the body can compensate for the reduction of tissue perfusion • When the compensated capabilities are overloaded SHOCK irreversible shock if undetected and untreated 10 PHYSIOLOGICAL RESPONSES DURING SHOCK • Systemic vascular constriction • Increased blood flow primarily to important organs (brain, heart) • Increased cardiac output • Increased respiratory rate and tidal volume • Decreased urine output • Decreased gastroenterological activity 11 COMPENSATED SHOCK • Defense mechanism try to maintain the blood perfusion to main organs by: – Constrict the pre-capillary sphincter, blood bypasses capillary through shunt – Increased heart rate and cardiac muscle contractility – Increased respiratory activity, bronchial dilation 12 COMPENSATED SHOCK • Progresses until causes of shock are treated or continues to next stage • Difficult to diagnose due to obscure symptoms – Tachycardia – Signs of reduced skin perfusion – Altered mental status • Some medication (B- blockers) could undermine the symptoms by preventing the tachycardia. 13 UNCOMPENSATED SHOCK • Physiological responses – – – – – Pre-capillary sphincter opens Hypotension Reduced cardiac output Blood accumulate in capillary bed Aggregation of the erythrocytes 14 UNCOMPENSATED SHOCK • Easier to diagnose than compensated shock: – – – – – Longer capillary refill time Marked increased heart rate Increased and thready pulses Agitated, disorientated and confused Hypotension 15 IRIVERSIBLE SHOCK • Failed compensated mechanism • Sometimes difficult to distinguish • Resuscitatable but high mortality (ARDS, ARF, hepatic failure, sepsis) • Prolonged organ ischemia, cellular death, MODS: brain, lung, heart and kidney • Coagulation disorders (DIC) 16 CELULAR O2 DIFFICENCY Cellular energy starvation Metabolic disorders Cellular O2 deficiency Anaerobic metabolism CELL DEATH A. Lactic production Metabolic acidosis 17 INITIAL ASSESSMENT AND MANGAGEMENT OF SHOCK • Initial clinical manifestation may be poor • Identification of the causes is not so as important as prompt treatment for shock • Aim of treatment is recover the circulatory volume and shock management • It is important to exam shock patient regularly to assess their response 18 ETIOLOGIES • Blood lost • Trauma • Fracture of long bone or opened fracture • Plasma lost due to burn 19 ETIOLOGIES • Fluid lost to third compartment • Causes: – Peritonitis – Burn 20 21 INTERNAL HEMORRHAGE • Hematemesis, black or bloody stools • Hemoptysis • Pleural effusion of blood (Hemothorax) • Peritoneal effusion of blood (Hemoperitoneum) 22 22 23 24 25 STAGES OF HEMORRHAGIC SHOCK 26 STAGES OF HEMORRHAGIC SHOCK • Stage 1: blood lost < 15% total blood volume • Stage 2: 15-30% total blood volume • Stage 3: 30-40% total blood volume • Stage 4: > 40% total blood volume 27 STAGES OF HEMORRHAGIC SHOCK Blood lost (ml) % blood volume Clinical signs SBP DBP Resp Rate Heart Rate Urine volume (ml) Treatment 1 <750 0-15 Slightly anxious Nor mal Nor mal 14-20 <100 >30 Crystalloid solution 2 7501500 15-30 Mildly anxious Nor mal 20-30 >100 20-30 Crystalloid solution or blood products 3 15002000 30-40 Anxious, confused 30-40 >120 5-15 Colloid and blood 4 >2000 >40 Confused Lethargic >40 >140 None Colloid and surgery 28 STAGE 1 • • • • • • • • • Blood lost < 750 mL Total blood volume (%): 0-15% Central nervous manifestation: slightly anxious Systolic BP: normal Diastolic BP: normal Respiratory rate: 14 - 20 BPM Pulse < 100 Urine output: > 30 ml/h Treatment : Crystalloid infusion (ratio 3/1) 29 STAGE 2 • • • • • • • • • Blood lost : 750 – 1500 mL Total blood volume (% ): 15 – 30% Central nervous manifestation: mild anxious Systolic BP: normal Diastolic BP: increased Respiratory rate: 20 - 30 BPM Pulse > 100 Urine output: 20 - 30 ml/h Treatment: Crystalloid or blood transfusion 30 STAGE 3 • Blood lost: 1500 - 2000 mL • Total blood volume (%): 30 – 40% • Central nervous manifestation: Anxious and confused • Systolic BP: decreased • Diastolic BP: decreased • Respiratory rate: 30 – 40 BPM • Pulse > 120 • Urine output: 5 - 15 ml/h 31 • Treatment: Crystalloid or blood transfusion STAGE 4 • Blood lost > 2000 mL • Total blood volume (%) > 40% • Central nervous manifestation: Confused Lethargic • Systolic BP: decreased • Diastolic BP: decreased • Respiratory rate > 40 BPM • Pulse > 140 • Urine output: Negligible • Treatment: colloid, blood and surgery 32 PITFALLS • Not all traumatic shock patients go through all 4 stages • In healthy young adults, the heart rate may be normal even patients are on stage 2 or 3 33 DIAGNOSIS 34 SEQUENCES OF EXAMINATION Order of ABC • A = Airway • B = Breathing: + O2 supply + Assisted ventilation 35 SEQUENCES OF EXAMINATION Order of ABC • C = Circulation: + Hemostasis by local bandage + Blood volume replacement by fluid infusion + Identification of obstructive shock: - Tension pneumothorax: prompt thoracocentesis - Cardiac tamponade: prompt Pericardiocentesis 36 Symptoms and diagnosis • Hemorrhagic shock: • Manifestations: – Obvious blood lost: Hematemesis, black or bloody stools. – Tachycardia, hypotension, low CVP. – Thirsty, dizziness, vertigo, agitation, LOC. – Pale, cold, sweating, cyanosis. 37 Symptoms and diagnosis • • • • Hemorrhagic shock: Respiratory disorders: tachypnea, cyanosis Oliguria, anuria Monitor, assessment of the severity of blood lost: – Orthostatic hypotension: BP > 20 mmHg, pulse > 20 BPM: 10-20% blood lost – Supine hypotension: >20% blood lost 38 Symptoms and diagnosis • Non-hemorrhagic shock (Hypovolemia): • Causes: dehydration or electrolyte disturbance • Manifestation: mainly symptoms of dehydration and electrolyte disturbance – ECF dehydration – ICF dehydration – Others: oliguria, cold 39 Consequences of shock Consequences of shock: • Kidney: acute renal failure • Lungs: ARDS • Heart: hypoxic heart failure, metabolic acidosis, cardiac muscle stress • GE: gastric ulcers or bleeding • Liver: failure • Pancreas: edema, necrosis • Endocrinological glands: pituitary gland is most vulnerable in bleeding necrosis (Sheehan syndrome) 40 MANAGEMENT 41 Emergency treatment Emergency treatment • Position: head down, open the airway • Breathing: O2 4-8 LPM. Ambu bag or endotracheal intubation for ARF • Monitoring for heart rate, blood pressure, SpO2, EKG • Basic labs: CBC, hematocrit, platelets, blood group, fibrinogen, prothrombin. 42 Emergency treatment • Large venous access: • 500-1000ml Ringer lactate (NaCl 0.9%)/15-20 min. Continue infusion until BP increase and heart rate slow down infusion rate • Fluid infusion helps to replace the blood lost until blood arrival 43 Emergency treatment • Large venous access: Blood transfusion should be started after 3 liters of fluid infusion If blood is not available, fluid infusion should be continued It should be remembered that fluid is not able to carry O2 44 Emergency treatment • Blood transfusion: for hemorrhagic shock • Packed red blood cells: targeted Ht 25 - 30% • Fresh plasma or packed platelet if platelet <50.000/mm3 or Prothrombin < 50% – Many trauma centers now resuscitate patients with a 1:1:1 strategy. For every unit of red blood cells, a unit of platelets and a unit of fresh plasma is given: • 1 unit blood cell : 1 unit plasma : 1 unit platelets • Consider auto transfusion 45 Emergency treatment • Urinary catheter placement • If fluid infusion and blood transfusion is adequate, CVP >7 but still hypotension: – Dopamine: 5- 20 g/kg/min – If failed: add Dobutamine – If failed: add Norepinephrine 46 Emergency treatment • Ventilatory support if respiratory failure is detected • Identify and treat the causes • Trauma operate 47 FLUID MANAGEMENT • Large venous access> 18 F if possible • 2 lines in case of stage 3-4 of shock • Vasopressors are not indicated if circulatory volume is not adequate 48 FLUID MANAGEMENT • Start with large bore venous access: + Can use compressor bag + Ringers lactate is common - Choose NS 0.9% if suspected hyperkalemia - NS 0.9% can be used for the line of blood transfusion. 49 POSITION OF INFUSION • Upper extremity peripheral vein: preferred precaution in case of upper extremity fracture • Central veins: sub-clavian and internal jugular vein: best choice even at stage 4 risk of pneumothorax (chest X ray is needed after procedure) 50 POSITION OF INFUSION • Femoral vein: easy and safe Precaution in case of abdominal trauma due to coincidental hemoperitoneum • Intraosseous infusion: easiest; especially in children; may also use in adult • Peritoneal infusion 51 CENTRAL VENOUS PRESSURE • CVP assesses the preload of right ventricle • CVP Catheters are not necessity in most trauma patients • CVP is more useful in trauma patients who have: + Predisposed heart failure + Intra ventricle pacemaker + Neurogenic shock + Myocardial contusion + Suspected tamponade 52 CVP IN TRAUMATIC PATIENTS • Low CVP (< 6 mmHg) hypovolemia - continue infusion or blood transfusion • High CVP (> 15 mmHg): + Cardiac overload (over blood transfusion) + Right heart failure (AMI) + Cardiac tamponade + Lung disease + Tension pneumothorax + Dislocation of catheter + Hypocalcemia 53 CVP IN TRAUMATIC PATIENTS Initial CVP Change in CVP Low No Low Increase Low or moderate High Decrease No Causes Solution Consistent with blood Increase infusion loss rate Good resuscitation Slow down infusion rate Continued blood loss Continue rapid infusion overload or Slow down infusion predisposed condition rate 54 CONTROVERSAL ISSUES • Fluid type? • When? • Rate? • Targets of hemorrhagic shock? • Opened of blunt trauma? 55 FLUID TYPE? 56 COLLOIDS • Albumin, hydroxyethylstarch, pentastarch, gelatin, dextran • Advantages: smaller volume, more intravascular volume, stronger fluid shift from extravascular to intravascular spaces • Disadvantages: expensive, allergic reaction and coagulation disorders 57 COLLOIDS • Cochrane. BMJ 1998: 317:235-40. – Objectives: effect of albumin on mortality rate – Study: multiple analysis of 30 trials (total number of patients: 1419) – Conclusion: albumin increased mortality rate in trauma patients 58 COLLOIDS • Cochrane 2003. – Objectives: compare the effectiveness between crystalloid and colloids – Study: albumin (18 trials); HES (7 trials); Gelatin (4 trials); Dextran (8 trials) – Conclusion: no difference in mortality on trauma, burn and surgery patients 59 HYPERTONIC SALINE • Advantages: less volume, longer intravascular half life, stronger water shift • Disadvantages: hypernatremia, hyperosmolarity, convulsion, coagulation disorders • Fluid types – Hypertonic salt (7.5% NaCl) +/- 6% dextran – Bolus 250 cc (~ 4ml/kg) in 5-10 min 60 HYPERTONIC SALINE • Cochrane 2003 – Objectives: evaluate the effect of hypertonic salt on mortality rate – Study: 25 trials – Conclusion: tendency of reduced mortality rate on hypertonic salt group • ROC Trial – Very large USA multicenter trial – No benefit of hypertonic saline (and perhaps harm) 61 CONTROLLED INFUSION • Also called permissive hypotension • Increase of BP before successful hemostasis may be harmful • Reasons: – Increased hydrostatic pressure – Dislodge the clot – Dilute the coagulation factors 62 CONTROLLED INFUSION • Excess and early infusion in blunt trauma increased the mortality • Controlled infusion seem to be better (targeted systolic BP 70 – 90) • Delayed infusion (until successful hemostasis) may be better • More research required on blunt trauma 63 OTHER MANAGEMENT • Blood transfusion: + Blood group O (-): immediately available + Type and screen (if needed within < 15min) + Type and complete cross-matched: 45-60 min • Emergency thoracostomy, Pericardiocentesis, aortic cross-clamping • Auto transfusion: blood from chest tubes 64 INDICATION FOR EMERGENCY BLOOD TRANSFUSION GROUP O (-) • No blood pressure on arrival • Many patients need transfusion at the same time • Blood group is not available 65 TRANSFUSION THE TYPE AND SCREEN & COMPLETE CROSSMATCHED • Type and screen blood: (5-10 minutes delay from blood bank) emergency transfusion but can wait > 10 minutes but less than 1 hour • Complete cross matched (45-60 minutes delay) stable patient who can wait 45-60 minutes 66 NON-HEMORRAGIC SHOCK • Hypovolemic shock (non-hemorrhage) + vomiting, diarrhea, water lost to “third compartment” + treated by Ringer’s lactate or normal saline + no need hemostasis • Anaphylactic shock + allergic reaction to anaphylactic agents + treated by epinephrine, anti-histamine and fluid infusion 67 NON-HEMORRAGIC SHOCK • Septic shock + May be late complication of trauma + Patient may have fever or hypothermia + Treated by fluid transfusion and isotopes + Identify and treat the causes of infection plays important role in trauma patients (initiate antibiotics and abscess drainage) 68 NON-HEMORRAGIC SHOCK • Obstructive shock: main symptom is cervical vein enlargement + Tension pneumothorax - Emergency decompression + Acute cardiac tamponade - Fluid infusion - Pericardiocentesis + Pulmonary embolism - Need definitive diagnosis - Fibrinolysis or surgery 69 NON-HEMORRAGIC SHOCK • Cardiac shock: pumping dysfunction + Acute myocardial infarction + Myocardial contusion - very rare even among blunt chest trauma + Treated by inotropes - Dopamine - Dobutamine 70 NON-HEMORRAGIC SHOCK • Neurologic shock: spinal cord injury + Due to peripheral blood vessel dilation + Usually coincide with relative bradycardia + Treated by fluid infusion and then inotropes • Spinal cord shock + paralysis and lost of reflexes + Can be totally recovered (within 24 hours) 71 HEMOSTASIS TECHNIQUES • Direct pressure on the bleeding site • Temporary tourniquets 72 73 74 MONITORING • • • • • • Mental status Heart rate, blood pressure, respiratory rate Urine output (target > 30 cc/h) Capillary refill time CVP Laboratory (less important) 75 LABORATORY • Hematocrit + may be normal at the beginning even though patients are in severe blood lost + lower at the beginning indicating that patients are in very severe blood lost • BUN + may be elevated if there is reduced blood volume to the kidney (functional renal insufficiency) or GI bleeding + Slightly elevated in children who are dehydrated 76 LABORATORY • Blood sugar: may be elevated due to stress • WBC: less value for diagnosis – Elevates following stress • Hypocalcaemia if transfused blood containing citrate, treatment is not necessary • Hypokalemia: temporary shift of potassium into cells from stress. Patients do not need potassium replacement. 77 CAUSES OF COAGULATORY DISORDERS • Hypothermia (temperature < 35.5oC) + most common reason + warm patient as quick as possible • Massive blood transfusion + lost of coagulation factors and platelet + transfuse 1 unit of frozen fresh plasma and 1 unit of packed platelet for every 6-8 units of packed RBC (note: many trauma centers now using a 1:1:1 ratio of prbc:plasma:platelets) 78 CAUSES OF COAGULATORY DISORDERS • Infection • Coagulopathy or predisposed hepatic failure • Adverse effects of medications or toxins 79 IRRIVERSIBLE SHOCK • • • • • • • • • Invisible dehydration Ventilatory problem Gastric distension Cardiac tamponade AMI Acute adrenal insufficiency Neurologic shock Hypothermia Medication or toxins 80 HYPOTHERMIA IN TRAUMA • Trauma patients at risk for hypothermia due to a variety of causes • Hypothermia results in increased blood loss (clotting disorders), increased risk of infection and increased cardiac dysfuntion/events • Prevent Hypothermia: – Warm all fluids being given to the severely injured trauma patients – Keep warm blankets on patient once unclothed – Frequently check patient’s temperature 81 BLOOD LOST IN BONE FRACTURE Position of fracture Amount of blood lost (mL) Tibia (closed) 500-1000 Femur (closed) 500-2500 Femur (opened) 1000->2500 Arm (closed) 500-750 Vertebral column (closed) 500-1500 Pelvic (closed) 1000->3000 Pelvic (opened) >2500 82 THANK YOU FOR YOUR ATTENTION 83