Paediatrics: Cardiovascular system difficulty - therapy - 1

2021-03-10 12:00 AM

Initial therapy includes the following.

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.