Management of shock in children

management of shock in children

1. Management of shock in children Resident (pediatrics department) Dr. Madan kr Timalsena KISTMCTH

2. OBJECTIVES Define shock Explain pathophysiology in short Explain clinical and severity classification of shock Explain initial evaluation of shock Explain initial management of shock Explain management of shock

3. What is shock ? Shock is a dynamic and unstable pathophysiologic state Characterized by inadequate tissue perfusion If not treated promptly leads to invariable progression and poor outcome leading to end organ damage , failure of multiple organ systems and mortality

4. Pathophysiology of shock: Can develop from variety of conditions: decreased intravascular volume ( hypovolemic shock) abnormal distribution of intravascular volume (distributive shock) impaired cardiovascular function ( cardiogenic shock) obstruction to cardiac outflow (obstructive shock) All of which leads to decreased tissue perfusion causing: Inadequate blood supply to vital organs Lactic acidosis due to anaerobic metabolism Release of inflammatory mediators Release of stress hormones causing glycolysis and lipolysis

5. Clinical classification and useful findings Hypovolemic shock History of volume loss or hemorrrhage Narrow pulse pressure Signs of poor peripheral perfusion Small/normal sized heart in chest radiograph Distributive shock(vascular dialation typically cause widened pulse pressure) specific features associated with types: Septic shock: fever , immunocompromised state , purpuric rash , abnormal white blood cell , DIC Anaphylactic shock: history of exposure to allergens , stridor , wheeze , vasodialation , urticaria ,facial edema Neurogenic shock:history of trauma with severe head or cervical spine injury ,hypotension , bradycardia

6. Cardiogenic shock : history of congenital heart disease Palpitation signs of heart faliure ( rales,hepatomegaly,gallop rhythm ,distended jugular vein) arrhythmia Obstructive shock History of thoracic trauma , Deviation of trachea Muffled heart sound , Pulsus paradoxus Abrupt circulatory collapse in PE (history of thrombophilia or sickle cell disease) Abrupt onset murmur , shock or cyanosis in duct dependent CHD ( crirical coarctaction of aorta, hypoplastic lt heart) with in 1 st few weeks of life due to closure of ductus arteriosus

7. Epidemiology of shock in children: Most common type of shock in children is hypovolemic Most common cause is diarrheal disease Sepsis is another common cause of shock especially in LBW newborn, younger children, and immunosupressed children Cardiogenic and obstructive shock are less common in children but must be considered as they are typically not fluid responsive and requires specific therapies

8. Initial evaluation of shock: Goals of initial evaluation: Immediate identification of life threatening condition( eg tension pneumothorax,hemothorax,cardiac tamponade,pulmonary embolism) Rapid recognization of circulatory compromise Early classification of type and cause of shock for early effective treatment

9. Helps in identifying a child with respiratory and circulatory compromise or both who require immediate supportive care and prompt evaluation

10. Appearance: Poor tone , unfocused gaze,weak cry may be indicators of decreased cerebral perfusion Subtle difference in appearance like decreased responsive to care takers or decrease response to painful procedure may be an important indicator of shock A child with depressed mental status as a result of shock may not ne able to maintain airway Other added sounds like stridor ,wheeze( anaphylaxis )crackles ( pneumonia,septic shock ) or decreased breath sound( pneumothorax ) give important information towards the cause of shock breathing :

11. Circulation: Poor perfusion can often be identified before BP measurement Decreased intensity of peripheral pulse in comparison to central pulses suggests peripheral vasoconstriction and compensated shock Bounding pulse may be present in distributive shock Skin temperature may be cold in children with compensated shock while warm temperature suggests peripheral vasodialation thus distributive shock Capillary refill >2 seconds suggests shock but flash capillary refill <1 second may be seen in distributive shock Tachycardia is frequent and early sign but bradycardia in spinal shock should always be kept in consideration

12. Tension pneumothorax : difficulty in breathing, decreased breath sound over hemithorax ,tracheal deviation,surgical emphysema,distended neck veins are seen where immediate needle decompression(2 nd intercostal space in mid clavicular line) is required Cardiac tamponade : respiratory distress,muffled heart tones,pulsus paradoxus are seen where pericardiocentesis is emergently required. Other such conditions are duct dependent CHD, pulmonary embolism. Children with severe respiratory distress and signs of circulatory compromise in initial assessment may have obstructive shock requiring immediate life saving intervention before further evaluation is initiated:

13. History: important points to consider History of fluid loss (AGE,DKA,GI bleed) is consistent with hypovolemic shock Injured children may have hypovolemic shock from hemorrhage or obstructive shock ( pneumothorax , cardiac tamponade ) or spinal shock( neurogenic ) Fever / immunocompromised state may indicate septic shock History of exposure to allergens (insect bites,sea foods) suggests anaphylactic shock Patients with chronic heart disease( cardiomyopathy,CHD ) may develop cardiogenic shock Adrenal crisis in suceptible patients should be considered(chronic steroid therapy, congenital adrenal insufficiency or sepsis)

14. Physical examination:complete physical examination with vitals and oxygen saturation Vital signs provide essential information regarding cause,classification and severity of shock: Respi rate: usally tachypneic . In capnography raised etco2 in response to metabolic acidosis is seen. Low etco2 is an ominous finding due to decrease pulmonary perfusion in shock. Heart rate: tachycardia is consistent and early sign( except for cardiogenic shock from bradyarrhythmia or spinal shock ) Blood pressure: children with shock may have normal BP however but hypotension if present should be rapidly identified as it rapidly progress to cardiovascular collapse and arrest Tempr : fever(or hypothermia in young infants) is often consistent with septic shock

15. Pulse pressure: Narrow pulse pressure typically <30mm of hg in older child occurs when diastolic blood pressure is increased as the result of compensatory increase in systemic vascular resistance eg with hypovolemic and cardiogenic shock Widening of pulse pressure typically>40mmof hg in older children seen in distributive shock as a result of decreased vascular resistance low pulse pressure may reflect widening of pulse in young infants

16. Additional features of physical examination Stridor or wheeze is heard in anaphylaxis Crackles may be heard in heart faliure ( cardiogenic shock) or pneumonia(septic shock) Asymmetric breath sound may suggest toward tension pneumothorax (obstructive shock) Distended neck veins suggests an abnormality of cardiac contractility or obstruction to venous return( tamponade,pneumothorax or hemothorax ) Pulse differntial in upper and lower limb suggests aortic coarctation Hepatomegaly due to hepatic congestion can be seen in heart faliure Abdominal distension,masses or tenderness is consistent with bowel obstruction,perforation or peritonitis Abnormal skin findings like urticaria or facial edema suggests anaphylaxis Purpura can be seen in septic shock

17. Approach to undifferentiated shock

18. Investigations: useful for successfully treating shock,identifying etiology,and monitoring response to treatment but should be obtained simultaneously with assessment and treatment Hypovolemic shock without hemorrhage Rapid glucose Serum electrolytes Blood lactate (marker of tissue perfusion and metabolic stress) Urine dipstick (specific gravity, glycosuria or ketonuria ) Chest x ray(who donot improve after 60ml/kg of fluid to rule out other cause ,to see cardiomegaly to taper fluid therapy) Abdominal x ray(to rule out third spacing) Hypovolemic shock with hemorhage Hematocrit ABG Blood type and cross match Coagulation studies(pt/ inr , aPTT ) Chest radiograph Abdominal radiograph/FAST scan if possible

19. Septic shock Rapid glucose ABG Complete and differential blood count Serum lactate Serum electrolytes Blood urea nitrogen and serum creatinine Ionized blood calcium Total bilirubin and alanine amino transferase PT/ INR,aPTT (to rule out DIC) Fibrinogen and d- dimer Blood culture Urine analysis/culture Inflammatory biomarkers like( CRP,ESR,procalcitonin )

20. Cardiogenic shock 12 lead ECG(mainstay) along with cardiac biomarkers to rule out arrhythmias Used in conjunction with clinical features and investigations to rule out other causes of shock as suspected Obstructive shock Chest x ray can be diagnostic for tension pneumothorax and hemothorax But whenever possible should be diagnosed clinically and urgently treated Ct chest in pulmonary embolism should be done only after initial stabalization (o2 support,fluid resuscitation,vasopressor support) Bedside transthorac or transesophageal echo can be useful in unstable patients to establish presumptive diagnosis and justify the use of thrombolytic therapy

21. Initial management of shock Targets of initial management of shock Strong distal pulse(equal to central pulse) Skin warm with capillary refill<2sec Normal mental status Systolic pressure >5 th percentile for age Urine output >1ml/kg/hr With in 5-15 min of recognition following action should be commenced: Give oxygen Monitor HR, oxygen saturation continiously and BP frequently Establish IV or IO access (preferably IV 22 -24 gauge for newborn and 18-20 gauge for children) Obtain blood glucose and treat hypoglycemia Identify life threatening obstructive cause of shock

22. In children without sign of fluid overload,isotonic crystalloid infusion(ringers lactate or normal saline) should be started Rapid infusion of 20ml/kg over five min should be performed in children who are hypotensive without findings of cardiogenic shock Patients with compensated shock should also receive 10-20 ml/kg over 5-20 min as long as there are no signs of cardiogenic or obstructive shock For children with signs of cardiogenic shock who may bw hypovolemic fluid should be given cautiously ( eg 5 to 10ml/kg over 15-30mins) Children with anaphylaxis should receive im epinephrine , diphenhydramine and glucocorticoid Other diagnostic studies should be obtained as indicated according to type of shock After initial bolus target physiological indicators should be evaluated

23. Over the next 15 to 60 min following action are warrented : Abnormalities in calcium and electrolyte measurement should be identified and treatment initiated Appropriate antibiotic therapy should be started for septic shock Children other than with obstructive and cardiogenic shock who have not improved with initial fluid bolus should continue to receive fluid boluses in 20ml/kg to a total of 60ml/kg over first 60 min of treatment Vasoactive drug therapy may be initiated in children with possible cardiogenic or neurogenic shock who have not responded to fluid Vasoactive agents should also be considered in septic shock who have not responded to 60ml/kg or more of fluid boluses Children who have not improved over 60 min of initial treatment should be reevaluated for other causes of shock

24. Commonly used drug and dosing: Epinephrine: for asystole or pulseless arrest (1:10000) iv or io at 0.1ml/kg every 3-5 min till return of spontaneous circulation Endotracheal (1:1000) at 0.1 ml/kg FOR iv INFUSION : 0.05 TO 1 MCG/KG/MIN ANAPHYLAXIS (1:1000) AT 0.01ML/KG/DOSE NOR-EPINEPHRINE: INITIALLY AT 0.05 T0 0.1 MCG/KG/MIN TIRATED AT MAXIMUM DOSE 2MCG/KG/MIN DOPAMINE: STARTED AT 2-20 MCG/KG/MIN WITH GRADUAL 5-10 MCG/KG/MIN UNTIL OPTIMAL RESPONSE DOBUTAMINE IN CARDIOGENIC SHOCK: INITIAL DOE 0.5-5MCG/KG/MIN IS TITRATED TO BP AND ENDORGAN PERFUSION TO MAXIMUM DOSE OF 20-40MCG/KG/MIN

25. Catecholamine resistant shock: Failure to maintain MAP above 65mmof hg or higher despite 6 hrs of vasopressor Treated with hydrocortisone 50mg/kg /day Patient not improving after hydrocortisone should be considered for ECMO

26. Disposition: Children whose shock resolve with treatment should be admitted for observation The cause of shock may persist and reoccur( eg diarrhoea ) Children who do not improve should be admitted to ICU Patient with hemorrhagic shock should be evaluated by trauma surgeon Failure to recognize nonn specific signs of compensated shock ( eg tachycardia,poor skin perfusion) pitfalls :

27. Inadequate monitoring Inappropriate fluid resuscitation(too little for hypovolemic shock or too much for cardiogenic and obstructive shock) Failure to reconsider other cause of shock in patients who are not improving Failure to recognize and obtructive shock due to life threatning condition Failure to consider multiple type of shock in single patient

28. Thank you!