先天性心脏病患者术后护理

Postoperative Care in the Patient With Congenital Heart Disease UTHSCSA Pediatric Resident Curriculum for the PICUUTHSCSA Pediatric Resident Curriculum for the PICU General Principles w Patient homeostasis nEarly declining trends do not correct themselves nLate time can be important diagnostic tool “The enemy of good is better” Specific Approaches w Cardiovascular principles w Approach to respiratory management w Pain control/sedation w Metabolic/electrolytes w Infection w Effects of surgical interventions on these parameters NO PARAMETER EXISTS IN ISOLATION Cardiovascular Principles w Maximize O2 delivery/ O2consumption ratio nOxygen delivery: lCardiac Output lVentilation/Oxygenation lHemoglobin Maximizing Oxygen Delivery Metabolic acidosis is the hallmark of poor oxygen delivery Maximizing Oxygen Delivery OXYGENOXYGEN DELIVERYDELIVERY OXYGEN OXYGEN CONTENTCONTENT CARDIAC CARDIAC OUTPUTOUTPUT X X = = O2 Content = Saturation(O2 Capacity)+(PaO2)0.003 w Oxygen Capacity = Hgb (10) (1.34) w So . . nHemoglobin and saturations are determinants of O2 delivery Maximizing 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 nContractility nDiastolic Filling nAfterload Heart rate nPhysiologic Response nNon-physiologic Response nSinus vs. junctional vs. paced ventricular rhythm Cardiac Cardiac OutputOutput StrokeStroke VolumeVolume HeartHeart RateRate = = X X Maximizing Oxygen w Oxygen consumption nDecreasing metabolic demands lSedation/ paralysis lThermoregulation Ventilator Strategies w Respiratory acidosis/hypercarbia w Oxygenation nPhysiology of single ventricle/shunt lesions nOxygen delivery! w Atelectasis 15-20 cc/kg tidal volumes. w PEEP, inspiratory times Ventilator Strategies: Pulmonary Hypertension w Sedation/neuromuscular blockade w High FiO2 no less than 60% FiO2 w Mild respiratory alkalosis npH 7.50-7.60 npCO2 30-35 mm Hg w Nitric Oxide Ventilator Strategies: Pulmonary Hypertension Precipitating Event -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 w Stress response attenuation w Limited myocardial reserve decreasing metabolic demands w Labile pulmonary hypertension w Analgesia/anxiolysis Pain Control/Sedation Opioids w MSO4 Gold standard: better sedative effects than synthetic opioids nCardioactive histamine release and limits endogenous catecholamines w Fentanyl/sufentanyl nLess histamine release nMore lipid soluble better CNS penetration Pain Control/Sedation Sedatives w Chloral hydrate nCan be myocardial depressant nMetabolites include trichloroethanol and trichloroacetic acid w Benzodiazepines nValium/Versed/Ativan Pain Control/Sedation Muscle relaxants w Depolarizing Succinylcholine nBradycardia ( ACH) w Non-depolarizing nPancuronium tachycardia nVecuronium shorter duration nAtracurium l“spontaneously” metabolized lHistamine release Pain Control/Sedation Others: w Barbiturates vasodilation, cardiac depression w Propofol myocardial depression, metabolic acidosis w Ketamine increases SVR w Etomidate No cardiovascular effects Fluid and Electrolytes w Effects of underlying cardiac disease w Effects of treatment of that disease Cardiopulmonary Bypass w “Controlled shock” w Loss of pulsatile blood flow nCapillary leak nVasoconstriction nRenovascular effects lRenin/angiotensin w Cytokine release w Endothelial damage and “sheer injury” Cardiopulmonary Bypass Stress Response SIRS Microembolic Events Renal Insufficiency Fluid Administration Hemorrhage Capillary Leak Syndrome Feltes, 1998 Lung Fluid Filtration = ( )-( ) Microvascular Hydrostatic Pressure Microvascular Oncotic Pressure Circulatory Arrest w Hypothermic protection of brain and other tissues w Access to surgical repair not accessible by CPB alone w Further activation of SIRS/ worsened capillary leak. Fluid and Electrolyte Principles w Crystalloid nTotal body fluid overload nMaintenance fluid = 1500-1700 cc/m2/day w Fluid advancement: nPOD 0 : 50-75% of maintenance nPOD 1 : 75% of maintenance nIncrease by 10% each day thereafter Fluid and Electrolyte Principles Flushes and Cardiotonic Drips nRemember: Flushes and Antibiotics = Volume UTHSCSA protocol to minimize crystalloid: Standard Drip ConcentrationUT