Paediatrics: Cardiovascular system difficulty - therapy - 1

Cardiovascular system difficulty: therapy - 1

Shock

Initial therapy includes the following.

• Oxygen: provide supplemental oxygen, FiO₂100%. Intubate if required.
• Position: in shock, elevate the legs to improve venous return. In congestive heart failure elevate the head.
• IV access: central access may be required, particularly when using inotropes.
• Temperature: control fever with antipyretics (paracetamol 15mg/kg).
• Metabolic state: correct hypoglycaemia and hypocalcaemia. Acidosis of respiratory cause should be controlled with ventilation.

Fluid volumes for shock

• Hypovolaemia: IV 20mL/kg of normal saline. In severe volume, depletion gives 40–60mL/kg of normal saline, with additional increments of 10mL/kg to restore volume if small heart size on CXR, and CVP <5–10mmHg.
• Stop resuscitation with volume:

when clinical improvement is achieved;

when clinical signs of improvement fail to appear;

if there are signs of volume overload: hepatosplenomegaly, JVP distension, gallop rhythm, wheeze and crackles.

 Inotropes for shock

• Start inotropes:

when circulation remains unsatisfactory and CXR shows large heart, pulmonary vascular congestion, pulmonary oedema, or pleural effusion;

when CVP >10–15mmHg; once initiated, titrate dose upward to produce the effect required.

• Hypotension with tachycardia:

dopamine—1–20microgram/kg/min (start at 5microgram/kg/min).

dobutamine—2–20microgram/kg/min (start at 5microgram/kg/min). Can use peripheral IV.

Dysrhythmias

Sinus bradycardia and heart block

• Do not treat if haemodynamically stable (i.e. BP and perfusion).
• Consider other treatable causes of bradycardia, such as raised ICP, acidosis, or hypercapnia.
• Atropine: 0.02mg/kg IV (min 0.1mg; max 1mg).

Intensive care treatments for shock

Hypotension with normal or low HR

• Adrenaline: 0.05–1microgram/kg/min (start at 0.05–0.10 microgram/kg/min)
• Noradrenaline: 0.05–1microgram/kg/min (start at 0.05–0.10microgram/kg/min)
• Amrinone: load 0.75mg/kg IV over 3min, then give 5–10microgram/kg/min

Hypotension refractory to volume and single inotrope

• Seek intensive care advice as these patients will usually need intubation and ventilation, and steroids
• Combinations of inotropes are used in this instance
• Afterload reduction may be required with sodium nitroprusside: 0.5–7micrograms/kg/min (start 0.5microgram/kg/min)

Diuresis for volume overload

• Start diuretics: after circulation is restored expected urine volume is1mL/kg/hr
• If oliguria or anuria use furosemide 0.5–1mg/kg IV or mannitol 0.5–1g/kg IV

Tachydysrhythmia—SVT

Treatment will require consultation with a cardiac specialist. If haemodynamically stable, consider the following:

• Vagal manoeuvres: ice bag to face for 15–20s or unilateral carotid massage or Valsalva manoeuvre. Do not compress orbits.
• Adenosine: 50–100micrograms/kg initially, as rapid IV push.
• DC shock: synchronized countershock 1J/kg should be reserved for the haemodynamically unstable. Intubation and appropriate analgesia and sedation are required.
• Other drugs: amiodarone, procainamide, flecainide.

Ventricular tachycardia

If haemodynamically stable and pulse, consider the following after advice from the cardiac specialist:

• If pulse present: amiodarone 5mg/kg; synchronized shock.
• Pulseless.