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This article discusses the definition of traumatic shock, the recognition of different stages and severity, and the management of shock based on these factors.
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TRAUMATIC SHOCK Do Ngoc Son MD., PhD.Emergency DepartmentBach Mai Hospital, Hanoi
Objectives • Definition of traumatic shock • Recognition of shock stages and severity • Management of shock according to stages and severity
DEFINITION OF SHOCK • Inadequate organ perfusion and tissue oxygenation. • Circulatory system failed to meet the metabolic demand of the body
Preload Stroke volume Cardiac output Blood pressure ARTERIAL BLOOD PRESSURE Cardiac contractility Afterload Heart rate Systemic vascular resistance
BOOD PRESSURE REGULATION(ROLE OF NEURO-ENDOCRINE SYSTEM) • Pressure receptors located at the aortic arch and carotids • Sympathoadrenal axis regulate the relieve of catecholamine • Renin-angiotensin-aldosteron system blood vessel tone and urine secretion
BLOOD VOLUME BLOOD VOLUME
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
PHYSIOLOGICAL RESPONSES DURING SHOCK • Systemic vascular constriction • Increased blood flow to important organs (brain, heart) • Increased cardiac output • Increased respiratory rate and tidal volume • Decreased urine output • Decreased gastroenterological activity
COMPENSATED SHOCK • Defense mechanism try to maintain the blood perfusion to main organs by: • Constrict the pre-capillary sphincter, blood bypass capillary through shunt • Increased heart rate and cardiac muscle contractility • Increased respiratory activity, bronchial dilation
COMPENSATED SHOCK • Progress until causes of shock are treated or continue to next stage • Difficult to diagnose due to obscure symptoms • Tachycardia • Signs of reduced skin perfusion • Altered mental status • Some medication such as propranolol could undermine the symptoms (B- blocker)
UNCOMPENSATED SHOCK • Physiological responses • Pre-capillary sphincter opens, hypotension • Reduced cardiac output • Blood accumulate in capillary bed • Aggregation of the erythrocytes
UNCOMPENSATED SHOCK • Easier to diagnose than compensated shock: • Longer capillary refill time • Marked increased heart rate • Increased and thread pulses • Agitated, disorientated and confused • Hypotension
IRIVERSIBLE SHOCK • Failed compensated mechanism • Sometimes difficult to distinguish • Resuscitable but high mortality (ARDS, ARF, hepatic failure, sepsis) • Prolonged organ ischemia, cellular death, MODS: brain, lung, heart and kidney • Coagulation disorders (DIC)
Cellular O2 deficiency A. Lactic production Cellular energy starvation Anaerobic metabolism Metabolic disorders Metabolic acidosis CELL DEATH CELULAR O2 DIFFICENCY
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
ITIOLOGIES • Blood lost • Trauma • Fracture of long bone or opened fracture • Plasma lost due to burn
ITIOLOGIES • Fluid lost to third compartment • Causes: • Peritonitis • Burn
INTERNAL HEMORRHAGE • Hematemesis, black or bloody stools • Hemoptysis • Pleural effusion of blood • Peritoneal effusion of blood 22
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
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)
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
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 • 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
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
SEQUENCES OF EXAMINATION Order of ABC • A = Airway • B = Breathing: + O2 supply + Assisted ventilation
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
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.
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
Symptoms and diagnosis • Non-hemorrhagic shock: • Causes: dehydration or electrolyte disturbance • Manifestation: mainly symptoms of dehydration and electrolyte disturbance • ECF dehydration • ICF dehydration • Others: oliguria, cold
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 • Pancreas: edema, necrosis • Endocrinological glands: pituitary gland is most vulnerable in bleeding necrosis (Sheehan syndrome)
Emergency treatment Emergency treatment • Position: head down, open the airway • Breathing: O2 4-8 LPM. Ambu bag or intracheal intubation for ARF • Monitoring for heart rate, blood pressure, SpO2, EKG • Basic labs: CBC, hematocrit, platelets, blood group, fibrinogen, prothrombin
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
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
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% • Consider auto transfusion
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
Emergency treatment • Ventilatory support if respiratory failure is detected • Identify and treat the causes • Trauma operate
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
FLUID MANAGEMENT • Start with large bore venous access: + Use with Peggy bag + Can use compressor bag + Ringer lactate is common - Choose NaCl 0.9% if suspected hyperkalemia - NaCl 0.9% can be used for the line of blood transfusion
POSITION OF INFUSION • Upper extremity peripheral vein: preferred precaution in case of upper extremity fracture • Central veins: sub-clavicle and carotid vein: best choice even at stage 4 risk of pneumothorax (chest X ray is needed after procedure)