Thresholds for intervention

• Aim to maintain mean arterial BP (MABP) ≥ gestational age in weeks
• Aim for even higher MABP in case of persistent pulmonary hypertension of the newborn [see Persistent pulmonary hypertension of the newborn (PPHN) guideline]

Assessment of cardiovascular status

• Measure BP:
  
  • by direct intra-arterial BP [umbilical arterial catheter (see Umbilical artery catheterisation and removal guideline) or peripheral arterial line (see Arterial line insertion) guideline]
  • automated oscillometry (Dinamap) has limited accuracy in hypotensive preterm babies; usually over-reads BP in the lower ranges 
• Assess tissue perfusion using as many of the following indices as possible (thresholds for abnormality in brackets): 
  
  • capillary refill time (>3 sec)
  • toe-core temperature difference (>2°C)
  • urine output (<1 mL/kg/hr)
  • rising lactate 

Causes of hypotension

• Sepsis
• Extreme prematurity
• Tension pneumothorax
• Blood loss
• Large patent ductus arteriosus (PDA) (see Patent ductus arteriosus guideline)
• Poor myocardial contractility (very-low-birth-weight, hypoxia, cardiomyopathy or hypocalcaemia)
• Polyuria secondary to glucosuria
• Third spacing (surgical causes – NEC/perforation/malrotation/obstruction)
• High positive intrathoracic pressure (high MAP on conventional/HFOV)
• Severe acidosis (pH <7)
• Drugs (morphine, muscle relaxants and anti-hypertensives)

Transilluminate chest to exclude pneumothorax (see Transillumination of the chest guideline)

Fluid

• Give if hypovolaemic (not >10 mL/kg) unless evidence of fluid/blood loss/sepsis (late onset sepsis/term babies), when it may be necessary to give more than this volume, depending on condition of baby. Otherwise, start inotropes first (see Inotropes)
• If clinical condition poor, BP very low, or mother has been treated with IV anti-hypertensive agent, give inotrope after fluid bolus

Which fluid?

• Use sodium chloride 0.9% 10 mL/kg over 10–15 min except when there is:
  
  • coagulopathy with bruising: give fresh frozen plasma 10 mL/kg over 30 min (see Coagulopathy guideline)
  • acute blood loss: give packed cells 10 mL/kg over 30 min

• If hypotension persists, start inotropes – seek senior advice

Inotropes

• Start dopamine at 5 microgram/kg/min

• Reassess every 15–20 min

• If still hypotensive, increase dopamine to 10 microgram/kg/min

  • if still hypotensive, add dobutamine at 10 microgram/kg/min 

  • if still hypotensive, increase dobutamine up to 20 microgram/kg/min 

  • if still hypotensive, increase dopamine up to 20 microgram/kg/min

  • give hydrocortisone 2.5 mg/kg IV (over 3–4 min) followed by 2.5 mg/kg IV 6–8 hrly for 2–3 days as necessary

• In babies with poor cardiac function, consider starting dobutamine first 
• In term babies requiring inotropes for pulmonary hypertension an infusion of noradrenaline or adrenaline may be required [see Persistent pulmonary hypertension of the newborn (PPHN) guideline]
  
  • consider milrinone in PPHN after evaluation of cardiac function and discussion with cardiologist

How

• Inotropes ideally given via central line
• When peripheral line used during emergency (see BNFc for dilutions), monitor site carefully for extravasation injury (see Extravasation injuries guideline)

Continuing hypotension

• Echocardiogram where possible to assess myocardial dysfunction/congenital heart disease

Refractory hypotension

If acidotic with severe hypotension, but not hypovolaemic

• Give adrenaline 100–1000 nanogram/kg/min (see BNFc for instructions on making up solution). If baby requires >1 microgram/kg/min (= >1000 nanogram/kg/min), consider other inotropes
• Monitor limb perfusion and urine output

• BP via arterial line (peripheral or UAC) (see Umbilical artery catheterisation and removal or Arterial line insertion guidelines)
• Check effective delivery of drugs: 
  
  • record volume in syringe hourly
  • check for leaks
  • ensure correct position of UVC or long line delivering inotropes
• Chest X-ray: 
  
  • if intubated
  • urgent, if respiratory status worsening
  • look for air leak or over-inflation
• Signs of tissue perfusion:
  
  • blood gases including lactate
  • urine output
  • capillary refill
  • heart rate
• Echocardiogram where possible to assess function and structure

• If already on morphine and muscle relaxant infusion, reduce dosage if possible
• In ventilated babies, especially those on HFOV reduce mean airway pressure cautiously without compromising chest inflation and oxygenation
• If baby acidotic and not responding to treatment, consider sodium bicarbonate 

Weaning inotropes if hypotension improves

• Wean inotropes (dopamine or dobutamine) in 5 microgram/kg/min decrements and adrenaline in 100 nanogram/kg/min decrements) as tolerated and directed by senior advice

Flowchart: Management of hypotension [If PPHN, see Persistent pulmonary hypertension of the newborn (PPHN) guideline]