Common Cardiac Lesions Flashcards
Summarise the management of a tet spell in theatre
The primary physiologic goal when managing a tetralogy spell (cyanosis following a sudden increase in PVR) is reducing the right-to-left shunt (through the VSD), i.e. re-directing blood through the lungs.
Pharmacologic management of tetralogy spells include β-blockade, alpha-agonism (increases both PVR and SVR, however if PVR is already elevated, does not have an additional effect), bicarbonate (acidosis can increase PVR), and morphine.
Non-pharmacologic strategies include administration of 100% oxygen (reduces PVR), knee-to-chest position (increases SVR and reduces the R-L shunt), and fluid administration (may increase the diameter of the RVOT).
Pharmacologic Treatment of Tetralogy Spell (Adapted from Smith)
β-Blockade: esmolol or propranolol (increased contractility is bad)
Phenylephrine: 5 to 10 mcg/kg IV
Bicarbonate: 1-2 mEq/kg. Normalizes SVR, decreases MV
Morphine: leads to sedation, decreases MV (increased PVR)
What is the presentation and management of a PDA at birth
Sudden onset respiratory failure, tachypnoea and tachycardia at birth with a widened pulse pressure.
Left to right shunt –> pulmonary congestion –> right heart failure. Reduced CO into systemic circulation –> left heart failure.
Also:
- systolic murmur
- Hyperdynamic praecordium
Treatment:
Fluid restriction
Diuretics
Indomethacin
What is the dose and frequency of administration of indomethacin for PDA
Initially —-> 0.2 mg/kg
12 hours –> 0.1 mg/kg
24 hours –> 0.1 mg/kg
Usually PDA closed by 24 hours
In which patients is indomethacin contraindicated for closure of PDA and why
Extremely LBW (< 1000 g)
Extremely preterm (<28 weeks)
Harm possibly exceeds benefit with high incidence of complications:
1. Thrombocytopaenia
2. Renal Failure
3. Electrolyte disturbances
4. Intestinal perforation
What are the options to close a PDA if medical therapy fails
- Surgery
- Percutaneous Amplatzer closure
What are the anaesthetic considerations in a patient with Trisomy 21
Airway: Macroglossia, tonsillar/adenoidal hypertrophy, micrognathia, short neck, OSA, cervical instability, small trachea
Cardiac: Congenital heart disease (in 50%, most commonly endocardial cushion defects)
Pulmonic: OSA, early development of pulmonary hypertension in L to R shunts
Neuromuscular: Developmental delay, hypotonia
What % of Trisomy 21 patients will have cardiac defects and list these defects in order of incidence
50% of Downs Syndrome patients will have a cardiac defect.
Atrioventricular septal defect (45%)
Ventricular septal (35%)
ASD (8%)
Patent ductus arteriosus (7%)
Tetralogy of Fallot
Classify esophageal atresia. Which is the most common type
Type A - blind esophageal pouch. No TEF
Type B - blind esophageal pouch. Prox TEF
Type C - blind esophageal pouch. Distal TEF
Type D - blind esophageal pouch. Prox and distal TEF
Type E - Esophageal narrowing. Distal TEF
Type C represents 85 - 90% of cases
50% of patients with esophageal atresia present with an additional abnormality usually from the VACTERL group
What does VACTERL stand for
Vertebral abnormality
Anus (Imperforate anus)
Cardiac anomalies
Tracheo-Esophageal fistula
Renal Dysplasia
Limb abnormalities
What are the Normal vital signs in kids
Age
(years) Heart rate
(beats per min) Respiratory rate
(breaths per min) Systolic blood pressure
50th centile (mmHg) Arterial oxygen saturation
(%) Urine output
(mL/kg/hr)
<1 110-160 30-40 80-90 95-98 1-2
1-2 100-150 25-35 85-95 95-98 1-2
2-5 95-140 25-30 85-100 95-98 1-2
5-12 80-120 20-25 90-110 95-98 >1
>12 60-100 15-20 100-120 95-98 >0.5
What are the features of a murmur in children that suggest structural heart disease (rather than an innocent murmur
Structural heart disease is more likely with the following clinical signs:
Pansystolic
diastolic murmur
grade 3 or higher
systolic click
increases in intensity with change of posture (supine to standing), or
the murmur has a harsh quality.
What are the characteristics of an ‘innocent’ heart murmur
Innocent murmurs:
1. Soft (Gr. 1/2)
2. Ejection systolic (or mid - stills)
3. Not associated with abnormal heart findings (thrills / pulse abN)
4. Positional (changes in intensity with position)
Pathological murmurs:
1. Loud (Gr 3/4)
2. Pansystolic or diastolic
3. Associated with thrill or pulse change, fixed splitting S2
4. Non-positional
5. Symptoms of heart disease
What are the causes of some common ‘innocent’ murmurs
Physiologic flow murmu
Still’s murmur = midsystolic (‘false tendon LV)
Pulmonary flow
Venous hum
