common paediatric respiratory conditions corrine balit
TRANSCRIPT
Common Paediatric Respiratory conditions
Corrine Balit
Outline
Respiratory Distress : Signs and Treatment
Respiratory SupportsHigh Flow Nasal prong CPAP/ BIPAPVentilation
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
RespRR 90Tracheal tug Intercostal and subcostal recessionGruntingHead bobbing, nasal flaring
CVSHR 200Cap refill 3 secondsMottled
NeuroAgitated, 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/hypercarbia
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 GasCarbon dioxide and pHLactate
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.
IndicationsMod- Severe respiratory distress despite basic
treatmentRecurrent apnoeasRespiratory acidosis (pH < 7.2) Increasing oxygen requirementsChange in mental stateNeeding 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 adjunctsSalbutamol +/- ipratropium Steroids if indicated
Respiratory Distress
RR < 60Mild-Mod Work of breathingOxygen requirement < 2LNot irritable/agitated
RR >60Mod-severe work of breathingIncreasing oxygen requirementIrritable/agitated
Basic Measures Nil by mouthCannula + IVF Humidified oxygen total flow of 2-3LAdjuncts 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 supportHigh Flow nasal prong oxygenCPAPBIPAP
Mechanical ventilation IPPVHFOV
ECMO
Treatment of Respiratory Distress
Fluid ManagementGenerally restricted if receiving ventilatory supportTwo- thirds maintenanceNormal saline or Hartmann's as fluid for severe resp
distressWatch EUC
FeedsFeed 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 capacityUse of humidification
Humidification improves mucocillary clearance
Advantages:Tolerated better by childrenAvoid some of CPAP complication like nasal mucosal
injury
High Flow Nasal Prong oxygenFlow rates currently recommended up to 8L/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 8L/min flow rate delivered on average a CPAP effect of 4 cm H20 in infants with viral bronchiolitis
Definition of High flow nasal prong cannula1L/kg/minCurrent cannula for paediatrics up to 8L flow.
High Flow- Indications
Respiratory distress with hypoxemiaBronchiolitisPneumonia
Post extubation respiratory support
Facilitation of weaning from CPAP
Post operative respiratory failure
High Flow- Contraindications
Nasal obstruction Choanal atresiaLarge 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 (<10kg)
PEEP 5-10cm
Contraindications If airway protection is neededDecreased level of consciousnessNasal 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 CareOxygenSuctionFluids / 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- agonistsMeta analysis: modest short term improvement in
clinical scores, without changes in oxygen saturation, rate of hospitilisation or length of hospital stay
AdrenalineRCT comparing adrenaline nebulised with placeboNo difference in length of hospital stay and no short
term or long term clinical improvement
Bronchiolitis – Specific TreatmentsCorticosteroids
Controversial, conflicting studiesCochrane review: no benefits in either length of stay
or clinical course in infants
SurfactantPromising as RSV affects endogenous surfactant
productiongiven 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 IVNo improvement on clinical outcome
PalivizumabMonoclonal antibodyFor prophylaxis for high risk infantsExpensive50% decrease in need for hospitlisation in high risk
infants
Bronchiolitis – Specific Treatments
Ipratropium bromideNot been demonstrated to be efficacious
HelioxHelium-oxygen gasProspective study looking at 70% helium, 30%
oxygen mixture- improved tachypnoea and tachycardia and shorter stay in PICU
Nitric oxideCase 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 2010Secondary 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 IPPVHFOVECMO
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 supportHigh flow Nasal prong Cannula to 8L/min (not available
in ED)Bubble CPAP
OG or NG if on respiratory support
Constant reassessment, looking forDecreasing respiratory rateDecrease in work of breathingHeart 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 inVery young infantsWCC > 100 000Presenting with pneumoniaNeed for circulatory support
Indications for ICUApnoeasSeizure Severe respiratory failure
Pertussis - Investigations
PCR on NPA
CXR
WCC
ECHO if severe
Pertussis- Management
Suction
Oxygen
Respiratory supportHigh flow nasal o2CPAPVentilation
Antimicrobials Azithromycin
Pertussis- Other Management
If leukocytosis (esp neutrophilia)Exchange transfusions or aphaeresis to remove
white cellsWith high white cell count can get leukocyte
aggregates in pulmonary vessels
If Pulmonary Hypertension presentConsider inhaled nitric oxide or sildenafil
If Severe respiratory failureECMO
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-receptorsPromotes 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 B2
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
functionNo difference in length of stay