Postoperative Care in the Patient With Congenital Heart Disease

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Postoperative Care in the Patient With Congenital
Heart Disease
UTHSCSA Pediatric Resident Curriculum for the PICU
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General Principles

• Patient homeostasis
• Early declining trends do not correct
  themselves
• Late time can be important diagnostic tool
• The enemy of good is better

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Specific Approaches

• Cardiovascular principles
• Approach to respiratory management
• Pain control/sedation
• Metabolic/electrolytes
• Infection
• Effects of surgical interventions on these
  parameters
• NO PARAMETER EXISTS IN ISOLATION

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Cardiovascular Principles

• Maximize O2 delivery/ O2consumption ratio
• Oxygen delivery
• Cardiac Output
• Ventilation/Oxygenation
• Hemoglobin

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Maximizing Oxygen Delivery

• Metabolic acidosis is the hallmark of poor oxygen
  delivery

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Maximizing Oxygen Delivery
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Maximizing Oxygen DeliveryCardiac Output

• O2 Content
• Saturation(O2 Capacity)(PaO2)0.003
• Oxygen Capacity Hgb (10) (1.34)
• So . .
• Hemoglobin and saturations are determinants of O2
  delivery

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Maximizing Oxygen DeliveryCardiac Output

• Gidding SS et al 1988
• y-0.26(x)38
• R0.77
• S.E.E.1.6

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Maximizing Oxygen DeliveryCardiac Output

• Stroke Volume
• Contractility
• Diastolic Filling
• Afterload

• Heart rate
• Physiologic Response
• Non-physiologic Response
• Sinus vs. junctional vs. paced ventricular rhythm

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Maximizing Oxygen

• Oxygen consumption
• Decreasing metabolic demands
• Sedation/ paralysis
• Thermoregulation

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Ventilator Strategies

• Respiratory acidosis/hypercarbia
• Oxygenation
• Physiology of single ventricle/shunt lesions
• Oxygen delivery!
• Atelectasis 15-20 cc/kg tidal volumes.
• PEEP, inspiratory times

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Ventilator StrategiesPulmonary 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

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Ventilator Strategies Pulmonary Hypertension
Precipitating Event -Cold stress -Suctioning -Acid
osis
The viscious cycle of PHTN
Metabolic Acidosis Hypercapnia
Increased PVR
Decreased Pulmonary Blood Flow Decreased LV
preload RV dysfunction Central Venous Hypertension
Hypoxemia Low output Ischemia
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Pain Control/Sedation

• Stress response attenuation
• Limited myocardial reserve decreasing metabolic
  demands
• Labile pulmonary hypertension
• Analgesia/anxiolysis

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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 CNS penetration

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Pain Control/Sedation

• Sedatives
• Chloral hydrate
• Can be myocardial depressant
• Metabolites include trichloroethanol and
  trichloroacetic acid
• Benzodiazepines
• Valium/Versed/Ativan

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Pain Control/Sedation

• Muscle relaxants
• Depolarizing Succinylcholine
• Bradycardia ( ACH)
• Non-depolarizing
• Pancuronium tachycardia
• Vecuronium shorter duration
• Atracurium
• spontaneously metabolized
• Histamine release

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Pain Control/Sedation

• Others
• Barbiturates vasodilation, cardiac depression
• Propofol myocardial depression, metabolic
  acidosis
• Ketamine increases SVR
• Etomidate No cardiovascular effects

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Fluid and Electrolytes

• Effects of underlying cardiac disease
• Effects of treatment of that disease

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Cardiopulmonary Bypass

• Controlled shock
• Loss of pulsatile blood flow
• Capillary leak
• Vasoconstriction
• Renovascular effects
• Renin/angiotensin
• Cytokine release
• Endothelial damage and sheer injury

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Cardiopulmonary Bypass
Stress Response
Microembolic Events
SIRS
Renal Insufficiency
Fluid Administration
Hemorrhage
Capillary Leak Syndrome
Feltes, 1998
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Circulatory Arrest

• Hypothermic protection of brain and other tissues
• Access to surgical repair not accessible by CPB
  alone
• Further activation of SIRS/ worsened capillary
  leak.

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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

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Fluid and Electrolyte Principles

• Flushes and Cardiotonic Drips
• 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(micrograms)/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
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Fluid and Electrolyte Principles

• Intravascular volume expansion/ Fluid challenges
• Colloid osmotically 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

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Metabolic Effects

• Glucose
• Neonates vs. children/adults
• Hyperglycemia in the early post-op period

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Metabolic Effects

• Calcium
• Myocardial requirements
• Rhythm
• Contractility
• Vascular resistance
• NEVER UNDERESTIMATE THE POWER OF CALCIUM!

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Calcium/inotropes
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Metabolic Effects

• Potassium
• Metabolic acidosis
• Rhythm disturbances

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Thermal Regulation

• As a sign to watch, and an item to manipulate
• Perfusion
• Junctional ectopic tachycardia
• Metabolic demands
• Oxygen consumption
• Infection

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Infection

• Routine anti-staphylococcal treatment

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Effects of Surgical Interventions

• Cardiopulmonary Bypass vs. Non-Bypass
• Fluids and electrolytes
• Modified ultrafiltration
• Types of anatomic defects
• Overcirculated increased blood volumes
  preoperatively
• Undercirculated reperfusion of area previously
  experiencing much reduced flow volumes.

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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.