a knackered neonate…

the case.

You are working in a district hospital and are called to the Special-Care Nursery to assist with an unwell newborn infant.

She was born 2 hours ago at 39 + 4 weeks gestation, to a primip mother who reports a completely unremarkable pregnancy and normal antenatal investigations (including morphology scans). The child has had marked respiratory distress and hypoxia since birth…

When you get to the resuscitaire, you find a child who just looks knackered!! She is grunting on nasal CPAP (which has been titrated up to 100% FiO2 & 7cmH2O !!) with a respiratory rate of 70, marked sternal/intercostal recessions and tracheal tug. The pulse oximeter reads 82% !!

This is her chest x-ray…

[DDET What do you think is going on here ??]

This CXR is far from normal. There are infiltrates within right hemithorax associated with possible lung collapse (or volume loss). The right hemidiaphragm is poorly defined and the mediastinal structures appear shifted towards the left. There is a gastric tube within the stomach.

The differential diagnosis of the dyspnoeic newborn includes;

• Transient tachypnoea of the Newborn
• Hyaline Membrane Disease (a problem of prematurity, not likely in this case).
  
• Persistent Newborn Pulmonary Hypertension.
  • Aspiration, Pneumonia etc.
  • Hypoplastic vasculature.
  • Idiopathic.
• Pneumothorax
• Cardiac pathology
  • Coarctation of Aorta
  • Hypoplastic Left Heart
• Congenital disorder
  • Diaphragmatic hernia
  • Lung anomaly (eg. pulmonary hypoplasia)
  • etc…

The obvious decision for us was that this child needs intubation for refractory hypoxia and severe respiratory distress. It was also going to facilitate safe transfer to the Tertiary Paediatric facility.

[/DDET]

[DDET Wanna tube ? How are you going to get this done ??]

NEONATAL INTUBATION.

Indications:

• Failure of BVM ventilation.
• Advanced life support.
• Hypoxia despite usual resuscitation & non-invasive means.
• Need for endotracheal suctioning.
  • Typically a non-vigorous infant exposed to meconium-stained amniotic fluid.
• Others;
  • Congenital diaphragmatic hernia or extreme low-birth weight.

Equipment:

• Monitoring [Pulse oximetry, ECG, BP, capnography]
• Oxygen source (preferably with air-oxygen blender).
• Face-mask. Self-inflating bag [250mL] &/or T-piece system (eg. we have the Neopuff)
• Suction
• IV access [consider umbilical catheter or intraosseous access]
• Endotracheal tubes [of various sizes, see below].
• Stylet/introducer.
• Laryngoscope.
  • Typically Size 1 (term delivery) or Size 0 (for pre-term).
  • Macintosh blade vs Miller (straight) blade.
• Laryngeal mask airway.
  • Size 1 can be used up to 5kg of weight.
• Gastric tube [post-intubation].
• Tapes etc. for securing airway.

Endotracheal Tubes:

How about the distance of insertion…?

ETT Distance = weight (in kg) + 6.
eg. 2 kg infant; ETT is 8cm at lips.

Positioning:

The child is placed supine, in the neutral position (ie. slightly extended). This may require a towel or blanket beneath the child’s shoulders.

** image taken from Madar. Resuscitation of the newborn, 2011. **

Drugs:

• Morphine: 0.1 – 0.2 mg/kg
• Fentanyl: 1 – 2 micrograms/kg
• Suxamethonium: 1 – 2 mg/kg
• Atropine: 10 – 20 micrograms/kg
  • Varied opinions regarding “minimum dose atropine of 100mcg”.
  • Theoretical risk of paradoxical bradycardia at lower doses.

*** Important Note ***

Neonates will tend towards hypothermia very quickly, especially during the prolonged exposure of intubation.
Ensure adequate external heating, preferably from a resuscitaire !

 

[/DDET]

[DDET The story continues…]

Our patient is intubated uneventfully using morphine & suxamethonium.
This is her post-intubation chest x-ray….

 

• Allowing for penetration, both lung appear generally more aerated (especially the right apex). There now appears to be a rounded mass lesion in the right hemithorax.
• When our little patient gets on the ventilator, her oxygenation improves allowing us to wean to 40% FiO2 (& PEEP of 7cm). SaO2 settled at 94%.
• With the actual pathology in question, are neonatal transfer team arrive to retrieve her to our tertiary referral centre…

…as we are shifting our patient across to the transfer crib (one person taking head & tube, one lifting the rest of the child), she rapidly desaturates (Sats to 80%) with a brief bradycardia and period of hypotension…

[/DDET]

[DDET A sudden deterioration…]

How do you troubleshoot this clinical nightmare ??

Don’t forget the DOPE mnemonic…

• D – displacement/disconnect of tubing (including right mainstem tube, accidental extubation) 
• O – obstruction (sputum plugging, tube kinking etc.)
• P – pneumothorax
• E – equipment failure

In our patient’s instance;

• She is moved rapidly back to the hospital’s resuscitaire and reassessed.
• We disconnect from the ventilator and hand-bag through the ETT.
  • Lung compliance feels ok & we continue to get end-tidal CO2.
• There is no left-sided air-entry.
  • Is this pneumothorax…??

Well… we notice that during the move we have accidentally adopted a neck-flexion position. Looking back at the post-intubation x-ray, the tube has probably been advanced a little too far.

• Readjusting the child to the ‘neutral’ position, there is a reassuring improvement in her oxygenation and haemodynamics.
• Breath sounds can now be heard on the left.
• This was likely a right mainstem intubation, with the underlying pathology impeding adequate lung function.

Eventually (and safely) she is transferred out of our little district hospital !! Phew…

[/DDET]

[DDET The follow-up…]

• Our young patient arrives safely at the Tertiary Paeds centre.
• Further scans raise the idea that she has a CCAM (Congenital Cystic Adenomatoid Malformation)
• In her first week of life she is taken to theatre for resection.
• Surprisingly, the surgeons do not find a CCAM –> instead the final pathology = foetal lung interstitial tumour (FLIT).

This is her post-op CXR…

 

 

 

6 months later, she is going well….

[/DDET]

[DDET References.]

1. Airway Management and Mask Ventilation of the Newborn Infant. Guideline 13.4. Australian Resuscitation Council, 2010.
2. Tracheal Intubation and Ventilation of the Newborn Infant. Guideline 13.5. Australian Resuscitation Council, 2010.
3. Neonatal Intubation (NETS NSW Guideline)
4. Madar J. Resuscitation of the newborn. Anaesthesia & Intensive Care Medicine. 2011. 12(4), 135-140.
5. Barrington KJ. The Myth of a Minimum Dose for Atropine. Pediatrics. 2011; 127. p783.

[/DDET]