HYPOVOLEMIC SHOCKIN CHILDRENDr. B. Gebyar Tri B., SpA

- Medical Emergencies - Main cause of death in children worldwide ( 6 20 million/year ) Developing Countries : Diarrheal illness DHF North Am& Europe : Blood loss ( trauma ) Dr Sutomo : 6 8% of total pediatric ED patients Definition :Circulatory system failure to supply oxygen and nutrients to meet cellular metabolic demands

Pathophysiology : Adequate circulatory function depend on a combination of 3 major factors:

- Adequate blood volume

- Integrity and amintenace of vasomotor tone

- Cardiac output ( Pump )

Pathophysiology :Hypovolemia Compensatory Reflex Mechanism Baroreceptor Chemoreceptor Cerebral iaschemic receptor Humoral vasoactive substances Renal, salt, water Autotransfusion

Circul. VolumeCirculatory Volume Preload Stroke Volume Cardiac OutputBaroreceptor, Chemoreceptor, Cerebral ischemic receptor Cardio inhibitory centerCardiostimulatory centerSympathetic outputParasympathic outputHeart rate , Myocardial contractility Vasoconstriction Angiotensin, Vasopressin, Aldosteron

Autotransfusion

Effects of Defence Mechanism : - Vasoconstriction : Cold Extremeties Prolonged Cap. Refill - Tachycardia - Tissue perfussion : Anaerobic metabolism Metabolic acidosis - Arterio - venous O2 & CO2 different

Causes Water - Electrolyte Loss : Diarrhea/ Vomiting Diabetes Mellitus Diabetes Insipidus Heat stroke2. Blood Loss 3. Plasma loss : Burns Nephrotic Syndrome Dengue Hemor. Fever

Clinical Manifestation Depend on : - Etiology of Shock - Fluid loss ( quantities and rapidity ) - Duration and severity of shock - Stadium of shock

Stadium of shockIRREVERSIBLE Inadequate perfusion of vital organs; irreparable damage; death cannot be preventedCOMPENSATED Blood flow is normal or increased and may be maldistributed; vital organ function is maintainedUNCOMPENSATED Mcrovascular perfusion is compromised; significant reductions in effective circulating volume

Compensated Shock :- Blood loss + 25% Tachycardia and weak pulse Pale, cold & clammy skin Capil refill > 3 second Systolic BP normal apathetic Tachypneu

Decompensated Shock : - Blood loss 25 40 % - Tachycardia ++,weak pulse ++ - Syst BP - Capil Refill > 5 sec - Cold & mottled skin - Lethargy Irreversible- Blood loss > 40% Tachycardia++/ bradycardia/ pulseless BP Cold/deadly pale skin Sighing respiration ComaShock :

Diagnosis : Hx/History of diare,Vomiting,trauma,allergies,heart dis., fever Physical exam : Low BP ( less than 5th percentile ) Rapid and weak pulse/ pulseless Cold and clammy skin/ mottled skin Capillary refill > 3 sec Decreased mental status Decreased urine output Laboratory studies : CBC, Glucose, electrolyte, BGA, ECG,RFT Chest X ray DD/ Etiology

Treatment Airway management Secure AirwayAlways provide oxygenEndotrachintubation & controlled ventilation is suggested if respiratory failure or airway compromise is likely- elective is safer and less difficult- decrease negative intrathoracic pressure improved oxygenation and O2 delivery and decreased O2 consumption- can hyperventilate if necessary

Mainstay of therapy is fluid Aggressive volume resuscitation Goal directed therapies ( CI 3,3 6,0 ml/min/m2, O2 Consumption > 200ml/min/m2 ( Hb > 10 g% )Circulation Aggressive volume resuscitation decreased mortality from 58 % ( 1985 ) 18 % ( Pollack,1985; Ceneviva 1998 ) Large vol fluid for acute stabilization in childrenh have not been shown to increase rate of ARDS ( Carcillo 1991, Zadrobilek 1989 ) or cerebral edema ( Carcillo 1991, Powell 1990 )

CirculationBased on presumed etiology Rapid restoration of intravascular volumeIV - 60-90 secondsI.O. if less than 4-6 years oldCentral venous catheterUse isotonic fluid : NS, LR, or 5% albuminPRBCs to replace blood loss or if still unstable after 60cc/kg of crystalloidanemia is poorly tolerated in the stressed, hypoxic, hemodynamically unstable patient

Fluid refractory shock Inotropics

Vasoactive/Cardiotonic AgentsEpinephrine 0.05-0.1 mcg/kg/min: mostly beta-1, some beta-2 > 0.1 to 0.2 mcg/kg/min: alpha-1Dopamine 1-5 mcg/kg/min: dopaminergic 5-15 mcg/kg/min: more beta-1 10-20 mcg/kg/min: more alpha-1 may be useful in distributive shockDobutamine 2.5-15 mcg/kg/min: mostly beta-1, some beta-2 may be useful in cardiogenic shock

Norepinephrine0.05-0.2mcg/kg/min : only alpha and beta-1Use up to 1mcg/kg/min

Milrinone50mcg/kg load then 0.375-0.75mcg/kg/min: phosphodiesterase inhibitor; increased inotropy and peripheral vasodilation ( greater effect on pulmonary vasculature )

Phenylephrine0.1-0.5mcg/kg/min: pure alpha

Metabolic Issues : A c i d B a s eAdvere effect : hyperosmolarity, hypocalcemia, hypernatremia, left-ward shift of the oxyhb. dissociation curve Na Bic 1-2 meq/kg or = 0.3 x weight (kg) x base deficit Metabolic acidosis due to tissue hypoperfusion

Profound acidosis - depresses myocardial contractility - impairs the effectiveness of catecholaminesTx: fluid administration and controlled ventilation Buffer administration

Metabolic Issues Electrolytes :

Calcium is important for cardiac function and for the pressor effect of catecholamines

Hypoglycemia can lead to CNS damage and is needed for proper cardiovascular function

Check the BUN and creatinine to evaluate renal functionHyperkalemia can occur from renal dysfunction and/or acidosis

ShockBP , tachycardiCapilarry refill > 2 secDecreased mental statusOliguria/anuria Secure Airway, Oxygenation RL/Colloid 20 ml/kg/10 minute, up to over 60ml/kg/ h Fluid ResponsiveFluid Refr. ShockCap. Refill < 2 secUrine > 1ml/kg/hObserve in PICU SaO2, Blood Glucose BGA, ECG, Ca++ C V P Inotropic Fluid refractory-dopamine resistance Epinephrine, N E, VasodilatorCathecolamine Resistance ShockAdrenal Insufficiency +C V P FluidAdrenal Insufficiency - Hydrocortisone

Evaluation Circulation Heart rate, BP, perfusion, and pulses, liver size CVP monitoring may be helpfulRegardless of the cause: ABCs First assess airway patency, ventilation, then circulatory systemRespiratory Performance Respiratory rate and pattern, work of breathing, oxygenation (color), level of alertness

Cardiovascular AssessmentHeart RateToo high: 180 bpm for infants, 160 bpm for children >1year oldBlood PressureLower limit of SBP = 70 + ( 2 x age in years )Peripheral PulsesPresent/AbsentStrength (diminished, normal, bounding) Skin PerfusionCapillary refill timeTemperatureColorMottling CNS PerfusionRecognition of parentsReaction to painMuscle tonePupil size Renal PerfusionUOP >1cc/kg/hr

Treatment Solution Na+ Cl- K+ Ca++ Mg++ Buffer NS 154 154 0 0 0 None LR 130 109 4 3 0 Lactate Plasmalyte 140 98 5 0 3 Acetate & Gluconate Inotropic and vasoactive drugs are not a substitute for fluid, however...- Can have various combinations of hypovolemic and septic and cardiogenic shock- May need to treat poor vascular tone and/or poor cardiac function

Look for etiology of shock

Evaluate hemoglobin, hematocrit, and platelet count should be followed as these values may drop after fluid resuscitation

Shock from any etiology can lead to DIC and end organ damageCBC, PT, INR, PTT, Fibrinogen, Factor V, Factor VIII, D-dimer, and/or FDPs Check LFTs, follow CNS and pulmonary status

Think about inborn errors of metabolism

Lactate and pyruvateAmmonium, LFTsPlasma amino acids, urine organic acidsUrinalysis with reducing substancesUrine tox screen