Common Paediatric Respiratory conditions Corrine Balit Outline Respiratory

Common Paediatric Respiratory conditions Corrine Balit

Outline Respiratory Distress : Signs and Treatment Respiratory Supports High Flow Nasal prong CPAP/ BIPAP Ventilation Bronchiolitis Pertussis Asthma

Case 1: 6 week old E. L. 6 week old infant presents with severe respiratory distress Taken to resuscitation bay on arrival Call from ED doctor asking for help

Resp RR 90 Tracheal tug Intercostal and subcostal recession Grunting Head bobbing, nasal flaring CVS HR 200 Cap refill 3 seconds Mottled Neuro Agitated, Unsettled,

Respiratory Distress/ Failure One of most common reason ICU will need to review a patient Hard to determine which patients will need to come to ICU Clinical assessment and reassessment is most important May need to start some basic measures and then reassess again.

Increased work of breathing Malformations of chest wall Evidence of hypoxemia/hyperca rbia Tachypnea Large A diameter (barrel chest) Agitation Nasal Flaring Narrow AP diameter Confusion Chest wall retractions Somnolence Paradoxical breathing Cyanosis Agitation Grunting Accessory muscle use

Investigations Venous Blood Gas Carbon dioxide and p. H Lactate Oximetry Chest x-ray Other investigations to support underlying cause.

Who needs to come to ICU Clear cut ones that do and don’t In-between that is the hardest. Indications Mod- Severe respiratory distress despite basic treatment Recurrent apnoeas Respiratory acidosis (p. H < 7. 2) Increasing oxygen requirements Change in mental state Needing airway protection

Treatment of Respiratory Failure Administration of supplemental oxygen + consider humidification Evaluation of airway patency Clear secretions / Airway toileting to maintain airway patency Appropriate adjuncts Salbutamol +/- ipratropium Steroids if indicated

Respiratory Distress RR < 60 Mild-Mod Work of breathing Oxygen requirement < 2 L Not irritable/agitated RR >60 Mod-severe work of breathing Increasing oxygen requirement Irritable/agitated Basic Measures Nil by mouth Cannula + IVF Humidified oxygen total flow of 2 -3 L Adjuncts appropriate to condition e. g. salbutamol, steroids

Mod-Severe Respiratory Distress IV Cannula Oxygen + humidification Salbutamol, ipratropium, steroids Indications for ICU - Ongoing mod-severe respiratory distress despite above - Apnoeas - Respiratory Acidosis - Fatigue

Treatment of Respiratory Distress Specific treatment for conditions Non-invasive support High Flow nasal prong oxygen CPAP BIPAP Mechanical ventilation IPPV HFOV ECMO

Treatment of Respiratory Distress Fluid Management Generally restricted if receiving ventilatory support Two- thirds maintenance Normal saline or Hartmann's as fluid for severe resp distress Watch EUC Feeds Feed once stable and improving Can feed while receiving NIV support

High Flow Nasal Prong oxygen Delivered via nasal prong and using Fisher and Paykel System Rational is two fold: High flows provide positive distending pressure to the airway improving functional residual capacity Use of humidification Humidification improves mucocillary clearance Advantages: Tolerated better by children Avoid some of CPAP complication like nasal mucosal injury

High Flow Nasal Prong oxygen Flow rates currently recommended up to 8 L/Min Prospective study in Brisbane where the used flow rates between 1 and 8 L/min were used and they used electrical impedance tomography and oesophageal pressures measured. Found that using 8 L/min flow rate delivered on average a CPAP effect of 4 cm H 20 in infants with viral bronchiolitis Definition of High flow nasal prong cannula 1 L/kg/min Current cannula for paediatrics up to 8 L flow.

High Flow- Indications Respiratory distress with hypoxemia Bronchiolitis Pneumonia Post extubation respiratory support Facilitation of weaning from CPAP Post operative respiratory failure

High Flow- Contraindications Nasal obstruction Choanal atresia Large polyps Foreign body aspiration Children requiring airway protection Severe life threatening hypoxia (not a replacement for intubation

Non-Invasive Ventilation CPAP versus bi-level NIV Difficulties is with appropriate size mask Bubble CPAP good for infants (<10 kg) PEEP 5 -10 cm Contraindications If airway protection is needed Decreased level of consciousness Nasal obstruction

Invasive Ventilation Conventional Ventilation High Frequency Ventilation If intubating patient for severe respiratory distress suggest always using cuffed tube. Cuff doesn’t need to go up but there if you need it

Bronchiolitis

Bronchiolitis- aeitology Respiratory Syncytial Virus Para influenza virus Adenovirus Influenza virus Rhinoviruses Human metapneumovirus

Bronchiolitis- Pathology Loss of epithelial cells Cellular infiltration Oedema around airway Plugging of airway with mucus Can get complete and partial plugging of airways resulting in localised atelectasis and over distention in other areas. Imbalance of ventilation and perfusion leads to hypoxemia.

Bronchiolitis – Clinical Features Coryzal symptoms Wheezing Pneumonia Aponea Hyponatremia Seizures Encephalopathy Myocarditis

Investigations NPA Blood Gas CXR Septic workup if severe or very young FBC, EUC

Bronchiolitis- Indications for ICU admission Recurrent Apnoea Slow irregular breathing Decreased level of consciousness Shock Exhaustion Hypoxia Respiratory acidosis

Bronchiolitis- Management Supportive Care Oxygen Suction Fluids / Feeding Always Nil by mouth if moderate- severe IV fluids : 2/3 maintenance if moderate- Severe NG Tube Decompression of stomach Feeds once more stable Infection Control

Bronchiolitis – Specific Treatments Bronchodilators Surfactant Corticosteroids Ribavirin RSV Immunoglobulin Palivizumab Antibiotics

Bronchiolitis – Specific Treatments Bronchodilators B- agonists Meta analysis: modest short term improvement in clinical scores, without changes in oxygen saturation, rate of hospitilisation or length of hospital stay Adrenaline RCT comparing adrenaline nebulised with placebo No difference in length of hospital stay and no short term or long term clinical improvement

Bronchiolitis – Specific Treatments Corticosteroids Controversial, conflicting studies Cochrane review: no benefits in either length of stay or clinical course in infants Surfactant Promising as RSV affects endogenous surfactant production given to mechanically ventilated infants with RSV – shortened time on mechanical ventilation, Individual case reports and series. Limited evidence, very expensive

Bronchiolitis – Specific Treatments Ribavirin Antiviral Inhibits RSV replication Evidence supports aerolised use, IV can be given Early trials showed it to be effective No convincing benefit on clinical outcomes expect to patients post BMT with RSV

Bronchiolitis – Specific Treatments RSV- IG IV No improvement on clinical outcome Palivizumab Monoclonal antibody For prophylaxis for high risk infants Expensive 50% decrease in need for hospitlisation in high risk infants

Bronchiolitis – Specific Treatments Ipratropium bromide Not been demonstrated to be efficacious Heliox Helium-oxygen gas Prospective study looking at 70% helium, 30% oxygen mixture- improved tachypnoea and tachycardia and shorter stay in PICU Nitric oxide Case reports only

Bronchiolitis: Antibiotics Used for secondary bacterial infection Traditionally risk of secondary infection with RSV thought to be low but theses studies based on children not admitted to PICU. Recent studies: PCCM 2010 Secondary pneumonia in patients in PICU with RSV reported to be as high as 20 -50% If child is unwell enough to be admitted to PICU with bronchiolitis, cultures should be taken and antibiotics started

Levin et al PCCM 2010 Prospective study looking at patients admitted with RSV bronchiolitis with progressive respiratory failure Excluded patients who had pre-existing conditions Found 39% had probable pneumonia by tracheal aspirate Concluded that due to high rate of possible secondary bacterial pneumonia, empirical antibiotics for 24 -48 hrs pending cultures may be justified in those sick enough to come to PICU

Bronchiolitis- Ventilation High Flow Nasal Prongs CPAP Mechanical Ventilation IPPV HFOV ECMO

My Approach – to moderate-severe bronchiolitis Suction and clear airway esp nasal passages Application of oxygen with humidification if possible Nil by mouth IV cannula + 2/3 maintaince IVF Obtain venous blood gas (BC + FBC/EUC at time of IVC) Decide on level of respiratory support High flow Nasal prong Cannula to 8 L/min (not available in ED) Bubble CPAP

OG or NG if on respiratory support Constant reassessment, looking for Decreasing respiratory rate Decrease in work of breathing Heart rate improving If not responding to above to be intubated and ventilated If sick enough with bronchiolitis to need ventilatory support I do blood culture and sputum culture and cover with antibiotics. Need to monitor Sodium

Pertussis

Pertussis - Pathology Bordetella Pertussis Toxin damages respiratory epithelium and can produce systemic toxicity Severe, Prolonged Coughing Aponea in young infants Whoop- loud stridor on inspiration after a paroxysm

Pertussis- Severe Complications Pneumonia Pulmonary Hypertension Encephalopathy Seizures Global Myocardial dysfunction

Pertussis Mortality highest in Very young infants WCC > 100 000 Presenting with pneumonia Need for circulatory support Indications for ICU Apnoeas Seizure Severe respiratory failure

Pertussis - Investigations PCR on NPA CXR WCC ECHO if severe

Pertussis- Management Suction Oxygen Respiratory support High flow nasal o 2 CPAP Ventilation Antimicrobials Azithromycin

Pertussis- Other Management If leukocytosis (esp neutrophilia) Exchange transfusions or aphaeresis to remove white cells With high white cell count can get leukocyte aggregates in pulmonary vessels If Pulmonary Hypertension present Consider inhaled nitric oxide or sildenafil If Severe respiratory failure ECMO Treat contacts

PCCM 2007 Retrospective study from RCH Melbourne Median age at admission was 6 weeks 94% of patients were unimmunised at time of admission Infants presenting with pneumonia had raised white cell count 38% needing intubation died All patients who needed ECMO died

Asthma

Asthma – Management Oxygen B-adrenergic agonists Corticosteroids Anticholinergic Magnesium Sulphate Theophylline/ Aminophylline Inhalational anaesthetics

Asthma- Management Helium-Oxygen Non-invasive ventilation Ventilation Ketamine Adrenaline

B-adrenergic agonists Salbutamol first line bronchodilator of choice MDI with spacer as effective as nebulisation When giving nebulisation, continuous nebulization is superior to intermittent doses (Cochrane Review 2009) Provides sustained stimulation of B-receptors Promotes progressive bronchodilatation Improves drug delivery in distal airway

IV salbutamol Considered in patients unresponsive to treatment with continuous nebulisation. RCT in children 2002: IV salbutamol as a bolus , atrovent or IV salbutamol +atrovent In severe asthma, IV salbutamol as a bolus lead to more rapid recovery

Ipratropium bromide Leads to bronchodilatation by decreasing parasympathetic-mediated cholinergic bronchomotor tone Cochrane review 2009: Adding multiple doses of anticholinergic to B 2 agonists appears safe and improves lung function Would avoid hospital admission in 1 of 12 such patients No studies in critically ill children admitted to PICU Because safe, considered reasonable to use

Magnesium Sulphate Acts as calcium antagonist leading to smooth muscle relaxation 5 x RCT looking at IV magnesium in children 4 of these studies showed improvement in respiratory function and decrease in hospital admissions 1 study showed no significant difference between magnesium and placebo group 2 x meta analysis that showed adding magnesium provided additional benefit to children

Methylxanthines Theophylline and Aminophylline Role is in severe asthma who have failed other treatment Meta analysis of RCT in paeds found no benefit in mild or moderate asthma RCT in 163 children with status asthmaticus Aminophylline improved oxygen sats and pulmonary function No difference in length of stay