Post-operative Care in Pediatric Post-operative Care in Pediatric Open-Heart ProcedureOpen-Heart Procedure

Herbert G. Uy MD FAAPHerbert G. Uy MD FAAP

Pediatric Critical Care MedicinePediatric Critical Care Medicine

Systems important in Systems important in postoperative cardiac postoperative cardiac

managementmanagement• CNSCNS• CardiovascularCardiovascular• PulmonaryPulmonary• RenalRenal• Pain ControlPain Control• NutritionNutrition

Central Nervous SystemCentral Nervous System

• MonitorMonitor– SensoriumSensorium– PupilsPupils– ReflexesReflexes– Movement Movement

(symmetrical or (symmetrical or not)not)

– Sensory Sensory

• Sedated?Sedated?

Central Nervous SystemCentral Nervous System

• Morbidity?Morbidity?– Difficult SurgeryDifficult Surgery– Unstable condition prior to surgeryUnstable condition prior to surgery– Bypass complicationBypass complication

Cardiovascular - BasicCardiovascular - Basic

PreloadPreload

• Amount of volume filling ventricles Amount of volume filling ventricles during diastoleduring diastole

• Proportional to volume statusProportional to volume status• Increasing preload, increases Increasing preload, increases

stroke volume (in general)stroke volume (in general)• Monitor Preload using CVP,RAP, Monitor Preload using CVP,RAP,

LAPLAP

Preload Problems in post-op Preload Problems in post-op PatientsPatients

Either there is not enough preloadEither there is not enough preload

oror

The heart needs more than usualThe heart needs more than usual

Why too little?Why too little?

• Intraoperative Blood LossIntraoperative Blood Loss• Post-operative blood lossPost-operative blood loss

– CoagulopathiesCoagulopathies– HIT (heparin induced HIT (heparin induced

thrombocytopenia)thrombocytopenia)– Monitor CTT drainage and ReplaceMonitor CTT drainage and Replace

• Third SpacingThird Spacing

Why might they need more Why might they need more preload than usual?preload than usual?

• Stiff Right VentricleStiff Right Ventricle• Right Ventricular HypertrophyRight Ventricular Hypertrophy

– Tetrology of FallotTetrology of Fallot– Unbalanced AV-CanalUnbalanced AV-Canal

• Myocardial edemaMyocardial edema– Prolonged pump run, long cross Prolonged pump run, long cross

clampclamp– Generalized edema (anasarca)Generalized edema (anasarca)

Why else?Why else?

• Atrial arrhythmias or Junctional Atrial arrhythmias or Junctional rhythmsrhythms– No atrial ‘kick’No atrial ‘kick’

• Passive blood flow to the lungsPassive blood flow to the lungs

Preload - treatmentPreload - treatment

CrystalloidsCrystalloids

vs.vs.

ColloidsColloids

CrystalloidsCrystalloids

• Isotonic FluidIsotonic Fluid• Normal SalineNormal Saline

– 154 mEq NaCl/l154 mEq NaCl/l

• Lactated RingersLactated Ringers– 130mEq Na130mEq Na++

– 4mEq K4mEq K++

– 3mEq Ca3mEq Ca+2+2

– 109mEq Cl109mEq Cl--

– 28mEq Lactate28mEq Lactate

ColloidsColloids

• Oncotic propertiesOncotic properties• More likely to stay intravascularMore likely to stay intravascular• Longer duration of actionLonger duration of action• Less likely to contribute to edemaLess likely to contribute to edema• Some are actually quite usefulSome are actually quite useful

Commonly used colloidsCommonly used colloids

• 5% Albumin5% Albumin• 25% Albumin25% Albumin• Plasma - FFPPlasma - FFP• Packed Red Blood Cells (PRBC’s)Packed Red Blood Cells (PRBC’s)• PlateletsPlatelets• CryoprecipitateCryoprecipitate• Hespan/ Haes-SterilHespan/ Haes-Steril

Back to our diagramBack to our diagram

ContractilityContractility

• Often impairedOften impaired• Secondary to surgerySecondary to surgery• Increased workloadIncreased workload• Somewhat dependent on preloadSomewhat dependent on preload

Adrenergic AgonistsAdrenergic Agonists

• DopamineDopamine• DobutamineDobutamine• EpinephrineEpinephrine• PhenylephrinePhenylephrine

• MilrinoneMilrinone

DopamineDopamine

• Alpha, beta and dopaminergic agonistAlpha, beta and dopaminergic agonist• Dose range: 2-20mcg/kg/minDose range: 2-20mcg/kg/min• Effects: Low dose 2-5mcg/kg/minEffects: Low dose 2-5mcg/kg/min

– ‘‘renal’ doserenal’ dose– Middle range: more betaMiddle range: more beta– Higher range: alpha starts to predominateHigher range: alpha starts to predominate

• Use: inotrope, vasoconstriction, ‘renal’ Use: inotrope, vasoconstriction, ‘renal’ effectseffects

• Risk: ischemia, vasoconstriction, Risk: ischemia, vasoconstriction, tachycardiatachycardia

DobutamineDobutamine

• 1 selective1 selective• Dose range: 3-20mcg/kg/minDose range: 3-20mcg/kg/min• Effect: increased inotropy and Effect: increased inotropy and

chronotropychronotropy• Use: to increase contractility, Use: to increase contractility,

strength of contractionstrength of contraction• Risk: vasodilation in higher dose Risk: vasodilation in higher dose

range, tachycardiarange, tachycardia

EpinephrineEpinephrine

• Trade name AdrenalinTrade name Adrenalin• Ad/Renal/in = Above the kidneyAd/Renal/in = Above the kidney• Epi/Nephr/in = Above the kidneyEpi/Nephr/in = Above the kidney• works at all receptors works at all receptors >>• Dose range: 0.01mcg/kg/min - Dose range: 0.01mcg/kg/min -

2mcg/kg/min2mcg/kg/min• Use: most potent inotropic effectUse: most potent inotropic effect• Risk: vasoconstriction, ischemia, Risk: vasoconstriction, ischemia,

acidosis, tachycardia acidosis, tachycardia

MilrinoneMilrinone

• A phosphodiesterase inhibitorA phosphodiesterase inhibitor• Inhibits breakdown of cAMPInhibits breakdown of cAMP

Remember that diagram?Remember that diagram?

AfterloadAfterload

• Refers to work against which the heart Refers to work against which the heart is contractingis contracting

• Either an immediate obstruction such as Either an immediate obstruction such as valvular stenosis or hypertrophyvalvular stenosis or hypertrophy

• Or related to systemic vascular Or related to systemic vascular resistanceresistance

• As you might imagine decreasing the As you might imagine decreasing the afterload will help the heart to contractafterload will help the heart to contract

Afterload ReductionAfterload Reduction

• 3 drugs we use3 drugs we use• NitroprussideNitroprusside• NitroglycerinNitroglycerin• Nitric OxideNitric Oxide

Nitric OxideNitric Oxide

• FDA approved for treatment of FDA approved for treatment of Persistent Pulmonary Hypertension of Persistent Pulmonary Hypertension of the Newborn (PPHN)the Newborn (PPHN)

• Has been used to treat post operative Has been used to treat post operative pulmonary hypertension in congenital pulmonary hypertension in congenital heart diseaseheart disease

• Literature supporting its use outside of Literature supporting its use outside of PPHN is sparse and/or weakPPHN is sparse and/or weak

• Very expensive therapy - $3000/dayVery expensive therapy - $3000/day

NitroprussideNitroprusside

• Mechanism of action: NO donorMechanism of action: NO donor• Site of action: primarily on arteriesSite of action: primarily on arteries• Action: vasodilatorAction: vasodilator• Dose range: 0.3-7.0mcg/kg/minDose range: 0.3-7.0mcg/kg/min• Risks: profound hypotension, Risks: profound hypotension,

cyanide toxicity, cyanide toxicity, methemoglobinemiamethemoglobinemia

NitroglycerinNitroglycerin

• Mechanism of action: NO donorMechanism of action: NO donor• Site of action: veins and arteries, plus coronary Site of action: veins and arteries, plus coronary

arteriesarteries• Action: vaso and venodilatorAction: vaso and venodilator• Dose range: 0.3-5.0mcg/kg/minDose range: 0.3-5.0mcg/kg/min• Use: post-op Transposition, or other surgery Use: post-op Transposition, or other surgery

involving coronary arteriesinvolving coronary arteries• Risks: can decrease preload, profound Risks: can decrease preload, profound

hypotension, methemoglobinemia, cyanide hypotension, methemoglobinemia, cyanide toxicitytoxicity

Who needs afterload Who needs afterload reduction?reduction?

• Decreases force against which Decreases force against which heart has to contractheart has to contract

• Particularly needed for patients Particularly needed for patients with aortic insufficiency or mitral with aortic insufficiency or mitral regurgitationregurgitation– Can help to decrease the amount of Can help to decrease the amount of

regurgitationregurgitation• Poor LV functionPoor LV function

Pulmonary SupportPulmonary Support

• Two main goals:Two main goals:• OxygenationOxygenation• VentilationVentilation

VentilationVentilation

• General Goals: normal ventilation and General Goals: normal ventilation and minimum time on the ventilatorminimum time on the ventilator

• Passive Pulmonary Blood FlowPassive Pulmonary Blood Flow– Glen ShuntGlen Shunt– Fontan ProcedureFontan Procedure

• With passive blood flow, possibly more With passive blood flow, possibly more effect from airway pressures, want to effect from airway pressures, want to minimizeminimize– Lower Pmax, lower Inspiratory time, minimal Lower Pmax, lower Inspiratory time, minimal

peeppeep

Pulmonary HypertensionPulmonary Hypertension

• Seen in a variety of patientsSeen in a variety of patients– Most commonly those with lesions Most commonly those with lesions

that had big left to right shunts that had big left to right shunts (increased pulmonary blood flow)(increased pulmonary blood flow)

– Used to increased levels of blood flowUsed to increased levels of blood flow– ‘‘reactive’ pulmonary bedreactive’ pulmonary bed

• Atrioventricular CanalAtrioventricular Canal• Tetrology of FallotTetrology of Fallot

Treatment for Pulmonary Treatment for Pulmonary HTNHTN

• Classic:Classic:• HyperventilationHyperventilation

– pH 7.50-7.55pH 7.50-7.55– Similar to treatment of PPHN in the Similar to treatment of PPHN in the

neonateneonate• OxygenOxygen

– A potent pulmonary vasodilator, keep A potent pulmonary vasodilator, keep oxygen highoxygen high

OxygenationOxygenation

• What should be the IDEAL oxygen level What should be the IDEAL oxygen level after the surgery?after the surgery?– If complete correction with no shunt then If complete correction with no shunt then

Pa02 of 500 mmHgPa02 of 500 mmHg

• Is there a residual shunt?Is there a residual shunt?• Is there a pulmonary reason for the low Is there a pulmonary reason for the low

Pa02Pa02• Monitor using ABG and pulse oximeterMonitor using ABG and pulse oximeter

OxygenationOxygenation

• Pulse OximeterPulse Oximeter– Just a Monitor!!!Just a Monitor!!!– Will never replace Will never replace

ABG!!!ABG!!!• 40 mmHg = 70%40 mmHg = 70%• 50 mmHg = 80%50 mmHg = 80%• 60 mmHg = 90%60 mmHg = 90%

Renal Renal

• Diuresis is good but not too muchDiuresis is good but not too much• ATN common post-operativeATN common post-operative• 3 classes3 classes

– LoopLoop– ThiazideThiazide– OsmoticOsmotic

• Electrolyte Imbalance: HypoKalemia, Electrolyte Imbalance: HypoKalemia, HypoNatremia, HyperNatremia, HypoNatremia, HyperNatremia, HypoCalcemia, HypoMagnesemia, HypoCalcemia, HypoMagnesemia, HypoPhosphatemiaHypoPhosphatemia

RenalRenal

• Monitor Input and Output hourlyMonitor Input and Output hourly• Watch Vital SignsWatch Vital Signs

– BP, HRBP, HR– Pulse OximeterPulse Oximeter– PerfusionPerfusion

• Daily WeightDaily Weight

Pain AssessmentPain Assessment

• Patient Underwent Surgery!!!Patient Underwent Surgery!!!• Monitor BP, HR, RR, Facial Monitor BP, HR, RR, Facial

Expression, Body PositionExpression, Body Position• Scoring SystemsScoring Systems

– Oucher Analog ScaleOucher Analog Scale

• Patient may express discomfortPatient may express discomfort

Pain ControlPain Control

• Opiate analgesicsOpiate analgesics– Morphine sulfateMorphine sulfate

• NonSteroidal AnalgesicsNonSteroidal Analgesics– KetorolacKetorolac

• Should know the duration of action Should know the duration of action and side effectsand side effects

NutritionNutrition

• Dextrose/ glucose infusion is Dextrose/ glucose infusion is importantimportant

• Phosphorous needs for ATP Phosphorous needs for ATP formation and rhythm formation and rhythm maintainancemaintainance

• Electrolytes (Na, K, Ca, Mg)Electrolytes (Na, K, Ca, Mg)• Enteral vs. parenteral feedingEnteral vs. parenteral feeding• For Body repair and growthFor Body repair and growth

ReferencesReferences

• TextText– Rogers: Textbook of Pediatric Rogers: Textbook of Pediatric

Intensive CareIntensive Care– Critical Cardiac Disease of Infants and Critical Cardiac Disease of Infants and

ChildrenChildren

• On-lineOn-line– Picubook.netPicubook.net– Pedi-heart web-sitePedi-heart web-site

Thank You For Your Kind Thank You For Your Kind AttentionAttention

Have a Nice Day!!!Have a Nice Day!!!