Paediatric ICU: Acute Respiratory Distress Aylin Seven

CAUSES OF RESPIRATORY FAILURE Upper – croup/epiglottis Lower – bronchiolitis Lung – pneumonia/ARDS, pulmonary oedema Status Epilepticus Apnoea of prematurity Intoxication Trauma Neuromuscular Chest wall trauma Pleural effusion Pneumothorax Cardiac Metabolic Hypovolaemia Septic Shock

Why are kids so vulnerable? Metabolism Risk of apnoea Upper airway resistance Lower airway resistance Efficiency of muscles Endurance of muscles (less type 1) Lung volumes

Identifying the deteriorating patient Respiratory rate Work of breathing Bradycardia = BAD

PAT

Normal Respiratory Rates 1 month to 1 year  breaths/min 1-3 y  breaths/min 4-6y  20-24breaths/min 7-9  breaths/min

What to do next?!

What are your options? BMV HFO NIV Intubation + Mechanical Ventilation

Positioning etc… Midline sniffing position Prominent occiput in infants  towel roll under the shoulders Suction (remember nasal suctioning!) Nasal + oropharyngeal airways

HFO Indications: – Respiratory distress from bronchiolitis, pneumonia, heart failure – Post extubation – Weaning from mask CPAP/BiPAP – Neuromuscular disease – Apnoea of prematurity High flow can be used if there is hypoxaemia (SpO2<90%) and signs of moderate to severe respiratory distress despite standard flow oxygen. Contraindications: – Blocked nasal passages/choanal atresia – Trauma/surgery to nasopharanyx

Mechanisms of Action Delivered at near body temp, up to 100% relative humidity  delivering up to 8L/min in neonates without irritation Washout of inspiratory dead space  improves alveolar ventilation HFNC may stent the upper airway  reduce upper airway resistance Positive distending pressure (but signifcant affected by flow rate, leakage, cannula size)

NIV Bubble CPAP (Others: BiPAP/CPAP)

Bubble CPAP Indications: – Acute lower airway obstruction – Dynamic upper airway obstruction (laryngomalacia, tracheomalacia) – Parenchymal lung disease (e.g. pneumonia) – Ventilation weaning

Bubble CPAP Contraindications: – Severe cardiovascular instability – Poor respiratory drive (frequent apnoea/brady) – Congenital malformations of airway – NOTE: relative contraindication in >10-12kg

Bubble CPAP Mechanism: – Expiratory arm is under water  generates pressure and oscillations (almost similar to high frequency 15-30Hz) – Gentle bubbling = vigorous bubbling – No bubbling = loss of seal (often open mouth)

Intubation Some important differences in intubating kids: – Large tongue – High, anterior airway – Acute angle between tracheal opening and epiglottis – Narrowest diameter is cricoid ring (adults = vocal cords) – Laryngospasm (2 x more common in older children, and 3 x more common in younger children)  light sedation, secretions, extubation. Up to 96/1000 in URTI patients. – Cuffed vs uncuffed and oral vs nasal – ? Apnoeic oxygenation

Mechanical Ventilation Indications: – Apnea – Respiratory failure not responsive to O2, HFNC, CPAP, or BiPap – Neurologic compromise – Impaired cardiovascular function – Post-Operative states with impaired ventilatory function Some considerations in paediatrics: – Inspiratory time is usually s for full term babies  progressively increases to s by 8y – No difference in outcomes (mortality and length of ventilation) based on variety of modes including HFOV

Zebras and PICU Vascular rings/slings from aberrant vessels (pulmonary artery sling – anomalous L pulmonary artery and ductus encircling trachea) Congenital diaphragmatic hernia Spinal muscular atrophy Diaphragmatic palsy (post CTx surgery) Tick bite paralysis (toxin binds covalently to AchR) Tumours (neuroblastoma and lymphoma)

Case 1 10 month old Admitted to ward with bronchiolitis D3 Increased WOB on the ward  transferred to PICU Placed on WHO 2L/kg/min initially Ongoing significant work of breathing What next?

Case 1 Bubble CPAP  no significant improvement For intubation  unsuccessful intubation attempts x 3 Eventual intubation with sevoflurane induction

References HNE – ICU guidelines for care of paediatric airway, paediatric bubble CPAP Paediatric Airway Management, Santillanes and Gausche-Hill (2008) Ventilatory strategies in the neonatal and paediatrc intensive care units, Mesiano & Davis, Paediatric Respiratory Reviews (2008) Oh’s Intensive Care Manual 2013 The evidence for high flow nasal cannula devices in infants, Haq et al, Paediatric Respiratory Reviews (2014) Acute respiratory failure in children, Hammer, Paediatric Respiratory Reviews (2013)

Questions?