1、Postoperative Care in the Patient With Congenital Heart Disease,UTHSCSA Pediatric Resident Curriculum for the PICU,General Principles,Patient homeostasis Early declining trends do not correct themselves Late time can be important diagnostic tool “The enemy of good is better”,Specific Approaches,Card
2、iovascular principles Approach to respiratory management Pain control/sedation Metabolic/electrolytes Infection Effects of surgical interventions on these parametersNO PARAMETER EXISTS IN ISOLATION,Cardiovascular Principles,Maximize O2 delivery/ O2consumption ratioOxygen delivery: Cardiac Output Ven
3、tilation/Oxygenation Hemoglobin,Maximizing Oxygen Delivery,Metabolic acidosis is the hallmark of poor oxygen delivery,Maximizing Oxygen Delivery,O2 Content = Saturation(O2 Capacity)+(PaO2)0.003Oxygen Capacity = Hgb (10) (1.34) So . . Hemoglobin and saturations are determinants of O2 delivery,Maximiz
4、ing Oxygen Delivery Cardiac Output,Gidding SS et al 1988 y=-0.26(x)+38 R=0.77 S.E.E.=1.6,Maximizing Oxygen Delivery Cardiac Output,Maximizing Oxygen Delivery Cardiac Output,Stroke Volume Contractility Diastolic Filling Afterload,Heart rate Physiologic Response Non-physiologic Response Sinus vs. junc
5、tional vs. paced ventricular rhythm,Maximizing Oxygen,Oxygen consumption Decreasing metabolic demands Sedation/ paralysis Thermoregulation,Ventilator Strategies,Respiratory acidosis/hypercarbia Oxygenation Physiology of single ventricle/shunt lesions Oxygen delivery! Atelectasis 15-20 cc/kg tidal vo
6、lumes. PEEP, inspiratory times,Ventilator Strategies: Pulmonary Hypertension,Sedation/neuromuscular blockade High FiO2 no less than 60% FiO2 Mild respiratory alkalosis pH 7.50-7.60 pCO2 30-35 mm Hg Nitric Oxide,Ventilator Strategies: Pulmonary Hypertension,The viscious cycle of PHTN,Precipitating Ev
7、ent -Cold stress -Suctioning -Acidosis,Metabolic Acidosis Hypercapnia,Increased PVR,Decreased Pulmonary Blood Flow Decreased LV preload RV dysfunction Central Venous Hypertension,Hypoxemia Low output Ischemia,Pain Control/Sedation,Stress response attenuation Limited myocardial reserve decreasing met
8、abolic demands Labile pulmonary hypertension Analgesia/anxiolysis,Pain Control/Sedation,Opioids MSO4 Gold standard: better sedative effects than synthetic opioids Cardioactive histamine release and limits endogenous catecholamines Fentanyl/sufentanyl Less histamine release More lipid soluble better
9、CNS penetration,Pain Control/Sedation,Sedatives Chloral hydrate Can be myocardial depressant Metabolites include trichloroethanol and trichloroacetic acid Benzodiazepines Valium/Versed/Ativan,Pain Control/Sedation,Muscle relaxants Depolarizing Succinylcholine Bradycardia ( ACH) Non-depolarizing Panc
10、uronium tachycardia Vecuronium shorter duration Atracurium “spontaneously” metabolized Histamine release,Pain Control/Sedation,Others: Barbiturates vasodilation, cardiac depression Propofol myocardial depression, metabolic acidosis Ketamine increases SVR Etomidate No cardiovascular effects,Fluid and
11、 Electrolytes,Effects of underlying cardiac disease Effects of treatment of that disease,Cardiopulmonary Bypass,“Controlled shock” Loss of pulsatile blood flow Capillary leak Vasoconstriction Renovascular effects Renin/angiotensin Cytokine release Endothelial damage and “sheer injury”,Cardiopulmonar
12、y Bypass,Stress Response,SIRS,Microembolic Events,Renal Insufficiency,Fluid Administration,Hemorrhage,Capillary Leak Syndrome,Feltes, 1998,Circulatory Arrest,Hypothermic protection of brain and other tissues Access to surgical repair not accessible by CPB alone Further activation of SIRS/ worsened c
13、apillary leak.,Fluid and Electrolyte Principles,Crystalloid Total body fluid overload Maintenance fluid = 1500-1700 cc/m2/day Fluid advancement: POD 0 : 50-75% of maintenance POD 1 : 75% of maintenance Increase by 10% each day thereafter,Fluid and Electrolyte Principles,Flushes and Cardiotonic Drips
14、 Remember: Flushes and Antibiotics = Volume,UTHSCSA protocol to minimize crystalloid: Standard Drip Concentration Mix in dextrose or saline containing fluid to optimize serum glucose & electrolytes Sedation: (Used currently as carrier for drips) MSO4 2cc/hr = 0.1 mg/kg/hr Fentanyl 2 cc/hr = 3 mcg(mi
15、crograms)/kg/hr Cardiotonic medications: Dopamine/Dobutamine 50 mg/50 cc Epi/Norepinephrine 0.5 mg/50 cc Milrinone 5 mg/50 cc Nipride (Nitroprusside) 0.5 mg/50 cc Nitroglycerin 50 mg/50 cc PGEI 500 mcg/50 cc,Fluid and Electrolyte Principles,Intravascular volume expansion/ Fluid challenges Colloid os
16、motically active FFP 5% albumin/25% albumin PRBCs HCT adequate: 5% albumin (HR, LAP, CVP) HCT inadequate: 5-10 cc/kg PRBC Coagulopathic: FFP/ Cryoprecipitate Ongoing losses: CT and Peritoneal frequently = 5% albumin,Metabolic Effects,Glucose Neonates vs. children/adults Hyperglycemia in the early po
17、st-op period,Metabolic Effects,Calcium Myocardial requirements Rhythm Contractility Vascular resistanceNEVER UNDERESTIMATE THE POWER OF CALCIUM!,Calcium/inotropes,Metabolic Effects,Potassium Metabolic acidosis Rhythm disturbances,Thermal Regulation,As a sign to watch, and an item to manipulate Perfu
18、sion Junctional ectopic tachycardia Metabolic demands Oxygen consumption Infection,Infection,Routine anti-staphylococcal treatment,Effects of Surgical Interventions,Cardiopulmonary Bypass vs. Non-Bypass Fluids and electrolytes Modified ultrafiltration Types of anatomic defects Overcirculated increas
19、ed blood volumes preoperatively Undercirculated reperfusion of area previously experiencing much reduced flow volumes.,Summary,Optimize oxygen delivery by manipulation of cardiac output and hemoglobin Sedation and pain control can aid in the recovery Appreciate effects of cardiopulmonary bypass and circulatory arrest on fluid and electrolyte management Tight control of all parameters within the first 12 hours; after that time, patients may be better able to declare trends that can guide your interventions.,
