Congenital Heart Disease

							NON-CARDIAC
 SURGERY IN
  CHILDREN
     WITH
CONGENITAL
    HEART
   DISEASE
                      CHD
• 8 per 1000 live births
• ½ million patients in the US with repaired,
  palliated or unoperated CHD
• Advances in Mx increasing survival
• Trend to early repair
• Anesthetic mx complicated by diversity of CHD
  and wide spectrum of surgeries performed
• CHD adds significantly to the mortality of non-
  cardiac surgery
SPECTRUM OF CHD


                   Other
 VSD                          TGA
                   17%
 28%                           5%
                                  Coarctation
                                     5%

                             AS
ASD                          5%
10%                    TOF
        PS   PDA       10%
       10%   10%
 SPECTRUM OF INTERVENTION
• True correction
   – PDA, ASD, some VSD
• Correction with residua
   – Some VSD, Coartation of the Aorta
• Correction with sequelae
   – TOF, TGA
• Complications
   – Arrhythmias or conduction abn. from incisions or sutures
• Palliative surgery
   – B-T shunt, PA banding
• Cath lab interventions
   – Cure or palliation
          ISSUES TO RESOLVE
1.    Nature of repair
2.    Age and era of repair
3.    Ventricular outflow obstruction
4.    Ventricular dysfunction
5.    Arrhythmias and conduction abnormalities
6.    Hypoxemia
7.    Pulmonary Hypertension
8.    Endocarditis prophylaxis
9.    Extracardiac problems
10.   Monitoring
      NATURE OF THE REPAIR
1. ANATOMIC – LV to aorta
                  RV to pulm artery
                  circulation in series
                  cyanosis corrected
a) Simple Recon – ASD, VSD, PDA
                   treat as for normal heart
b) Complex – outflow tract (TOF, AS, PS, coarct)
             conduits or baffles (PA)
             septum and AV valve repair
      NATURE OF THE REPAIR
2. PHYSIOLOGICAL – single or 2 ventricle
                        circ in series
                        cyanosis relieved
                        significant sequelae
a) Two ventricle repair - RV is systemic
                          LV is pulmonary
b) Single ventricle
    TA, HRHS, double inlet/outlet ventricles
    Venous return directly to PA
    success: RA to LA pressure grad, n AV valve, vent fn
    serious potential problems
     AGE AND ERA OF REPAIR
The trend since the 80’s has shifted to early
  definitive repair, without prior palliation
Also since the 80’s TGA is repaired with arterial
  switch, not atrial.
VENT OUTFLOW OBSTRUCTION
LV: AS, Coarct, Interrupted Ao arch
     fatigue, syncope, chest pain, arrhythmia
RV: TOF, PS, conduit (PA/Truncus/TGA
 with PS), PVOD
 - conduits calcify and narrow
 - ischemic, hypertrophied RV
 - intracardiac defect may relieve pressure
 VENTRICULAR DYSFUNCTION
• Myocardial dysfunction insidious
• May not report symptoms
• History of decreasing exercise tolerance
• Objective evaluation useful
CAUSES: volume overload
             pressure overload
             chronic hypoxemia
             rec/sustained tachycardia
            ARRHYTHMIAS
• major impact after palliation or repair
• life threatening in abnormal heart

CAUSES: damage during surgery
        chamber dilatation
        myocardial hypertrophy
        meds, anes agents, electrolytes
               ARRHYTHMIAS
Supraventricular and sinus node:
- intra-atrial surgery
- elevated RA pressure
AV node and prox conducting tissue:
- VSD repair
- AV septal repair
- TOF
Ventricular:
- Pressure loaded eg AS
- Chr RV volume and pressure load eg TOF
Tachyarrhythmia and vent dysfn is dangerous
        HYPOXEMIA/CYANOSIS
2 causes:
- R to L shunt
- Admixture (Qp:Qs = 1:1         sats = 75-85%)
2 outcomes:
- Thromboembolism
  Chr hypoxemia        polycythemia       viscosity
- Coagulopathy
  Correlates with Hct
  Due to platelet and factor deficiency
 PULMONARY HYPERTENSION
Unrestricted L to R shunt       PBF & PAP
Affects ventilation
- Enlarged vessels obstruct airways
- Enlarged LA       venous congestion
Produces structural changes in pulm vessels
- medial hypertrophy, necrotizing arteritis
- PVOD
- PHT (labile vs fixed, severity)
         ENDOCARDITIS
Prophylaxis for all EXCEPT :
• Secundum ASD
• Repaired ASD, VSD, PDA > 6 months and
  no residua
• Resp – flex.bronchoscopy*, BMTs
• GIT – TEE*, endoscopy*
• GUT – circumcision, urethral cath
• Cardiac – cath, angioplasty
          ENDOCARDITIS
Above diaphragm:
Ampi or Amoxicillin 50mg/kg (PO 1hr, IV 30m)
Clindamycin 20mg/kg (PCN allergic)
Cefazolin 25mg/kg (mild PCN sensitivity)
Below diaphragm:
Ampi 50mg/kg + Gent 1.5mg/kg
+ Ampi or Amox 25mg/kg 6hr later (high risk)
Vanc 20mg/kg + Gent 1.5mg/kg (PCN allergic)
       PREOP ASSESSMENT
• Concerns on history
  – Failure to thrive, sweating, dyspnea (CCF)
  – Poor exercise tolerance
  – Rec. chest infections
  – PHT
  – Severe AS – syncope, lethargy
  – Uncorrected TOF – cyanosis, squatting
  – ? Prior surgery eg. Shunts, Fontan etc
       PREOP ASSESSMENT
• Examination
  – Active/well-nourished vs ill-looking
  – Cyanosis, sweating, tachypnea, dyspnea
  – Venous distension, hepatomegaly
  – Murmurs, crackles and wheezing
  – Check pulses
  – Neurological damage (CPB, paradoxical
    emboli, and cerebral abscess/infarct)
  – Airway
       PREOP ASSESSMENT
• Labs: Hct, K
• ECG: age-related, best evaluated by card.
• ECHO: recent
         type and severity of lesion
         ventricular function
         pulmonary pressure and O2 response
Close collaboration with cardiologist invaluable
INDICES OF CRITICAL IMPAIRMENT

1)   Chronic hypoxemia (sat < 75%)
2)   Qp:Qs > 2:1
3)   LV or RV outflow gradient > 50 mmHg
4)   Elevated pulmonary vascular resistance
5)   Polycythemia (Hct > 60%)
                  PREOP
•   Limit fasting
•   Cardiac meds; omit diuretic
•   Appropriate premed
•   Endocarditis prophylaxis
     GENERAL APPROACH
R to L shunt:           L to R shunt:
Avoid IV air; No N2O      PVR for large shunt
IV volume
 PVR (already low)       inotropy   dynamic
 SVR (phenyl 10mcg/ml   IV fluid    obstruction
  1-4mcg/kg)
Inhal~slower            IV~slower
End of Part 1