PAEDIATRIC RESPIRATORY AND OSA

Recent RTi: Proceed vs Postpone

Management of ‘Irritable Airways’

Asthma: Management of Acute Severe Episodes

OSA: Definitions and Risk Factors

Perioperative Anaesthetic Management

RHSC Guidelines for Postop Monitoring and Analgesia

Objectives

RTi and Anaesthesia

URTi increases perioperative adverse events:

Coughing

Breath holding

Laryngospasm/bronchospasm

SaO2 <90% for >10 secs

Unanticipated intubation/reintubation

Atelectasis/pneumonia

Risk is greatest in presence of active infection but remains increased for 2-6 weeks post RTi. Airway reactivity remains increased for 6-8 weeks post RTi

Mild URTi

Clear runny nose, apyrexial, normal activity/appetite

Minimal concern and usually proceed as planned

Purulent Nasal Discharge, productive cough

Clingy/irritable, lethargic, pyrexial, reduced activity and

appetite

Symptomatic RTiIdeally Postpone

Have to take into account: Procedure (complexity, priority)Ease of rearranging (staff, family)What’s normal for individual child

Discuss with surgeon

Discuss with family: Risk vs Benefit of Proceed vs Postpone

Low threshold to postpone if:

Age < 1 yearMajor op/airway opAsthma/atopy/other respiratory diseaseETT required 11x increased risk complication Cohen et al Anesthesia &Analgesia 1991

2.5 increased risk esp. < 5year olds Tait et al Anesthesiology 2001

Anaesthesia for the Irritable Airway

Preop: Consider β2 agonist + Steroid inhalers

Combination 10-30 mins preop reduced bronchoconstriction and

perioperative respiratory events more than salbutamol alone

Silvanus et al Anesthesiolody 2004

Induction: IV induction (propofol) less irritating than gas induction (sevo)

Limit airway stimulation/irritation (Facemask /LMA rather than ETT)

Consider lubricating LMA with lignocaine gel

Schebesta et al Can J Anesthesia 2010

Anticholinergics theoretically should reduce bronchoconstriction

but studies showed glycopyrrolate to be no better than placebo

Tait et al Anesthesia & Analgesia 2007

Maintenance: TCI (propofol) = Volatile (sevo) so long as maintain adequate depth

Fentanyl / Remifentanil reduce airway irritability

Airway humidification

IV hydration

Removal of LMA/ETT: Awake vs Deep no difference in complications

Tait et al Anesthesia & Analgesia 2005

Acute Severe Exacerbations

Airway inflammation

Excessive mucous production/plugging

Bronchospasm

Increased work of breathing Increased intrathoracic pressure

Reduced airflow PreloadAfterload

Air trapping Catecholamine depletion

Respiratory insufficiency/failure insensible losses dehydration

Previous sudden/rapid respiratory deterioration

Previous admission to PICU

Previous Ventilation

Syncope/seizures with asthma exacerbations

Poor adherence to recommended treatment

Poor control despite treatment/ oral steroids

Denial of severity/late presentation

Up to a third of children who die due to asthma were not previously identified as at risk of fatal asthma!

Recognised Risk Factors

Pharmacotherapy: To ease work of breathing

To achieve adequate oxygenation and ventilation

Monitoring: HR, RR, SaO2, conscious level/agitation, PEFR

accessory muscle use, wheeze

In HDU/PICU setting as prone to rapid deterioration

Clinical signs correlate poorly with severity of airway

obstruction

If possible endeavor to avoid intubation and ventilation

Management

Step 1 (no more than 30 minutes) (Grade 1A)

Salbutamol: MDI Salbutamol 100microgram x 10 puffs via spaceror

Salbutamol via Paediatric Nebuliser< 4 years of age 2.5mg > 4 years of age 5mg

(should be diluted to 4mls with normal saline)

Oral Prednisolone: < 1 year 2mg/kg 1-2 years 20mg 3-4 years 30mg

5+ years 40mg

High flow oxygen+SaO2 monitoring

If child requires nebulisers more frequently than half hourly then move to Step 2.

Scottish Paediatric Retrieval Guidelines

Step 2(1 hour) (Grade 1A)

Combined Salbutamol + Ipratropium nebulisers: x 3 over 1 hour

< 4 years of age: Salbutamol 2.5mg + Ipratropium 250microgram

> 4 years of age: Salbutamol 5mg + Ipratropium 500microgram

(diluted to 4mls with normal saline)

Apply Emla/Ametop cream in preparation for venous access.

Step 3(1hour)

Continuous Salbutamol nebulisers for 1 hour

Obtain IV access

Capillary blood gas, U+E, FBC, Blood glucose

Constant observation required with senior medical (consultant) input.

Move patient to High Dependency care.

Step 4 IV Medication

IV Hydrocortisone: 4mg/kg (max 100mg) 6hrly

IV Magnesium 50mg/kg MgSO4 (max 2g) over 20 mins (Grade 2A)

Cheuk et al Arch Dis Child (Metanalysis)

Should be used in severe asthma, or moderate asthma deteriorating despite β2 agonist/ipratropium/IV steroid

IV Salbutamol Loading dose 15mcg/kg over 15 mins (Grade 2B)

Maintenance 2-5mcg/kg/min

Nebulised Salbutamol continued half hourly

ECG monitoring and monitor serum potassium regularly

Contact PICU for advice / retrieval unless senior (consultant) medical staff are happy that adequate control is being gained.

Step 5

Intravenous Salbutamol: Max 10 mcg/kg/min in consultation with PICU

Repeat capillary blood gas, blood potassium and blood glucose .

(continue to monitor potassium regularly)

Apply Emla/Ametop cream should a second cannula be required

Contact PICU for advice / retrieval

Step 6

Ondansetron: 0.1mg/kg (max 4mg)

IV Aminophyline: Loading dose 5mg/kg over 20 mins

Maintenance 1mg/kg/hr

Do not mix with intravenous Salbutamol

Repeat capillary blood gas, blood potassium and blood glucose

Contact an Anaesthetist to review patient.

Ongoing discussion with PICU

Decision made on case by case basis

Reserved for cases who continue to deteriorate despite maximal medical treatment.

Estimated 2-3% mortality in children ventilated for acute severe asthma

Securing the airway does not cure the problem:

Instrumenting reactive airway

CV instability

Difficulties with ventilation remain

Indications for Intubation in Severe Asthma

No guideline or consensus to predict precisely when ETT may be required

Fatigue/somnolence/reduced conscious level

O2 despite FiO2

Progressive CO2 despite maximal treatment

Unable to speak/exhausted from work of breathing

Respiratory/cardiorespiratory arrest

RSI: PreoxygenationKetamine + Fentanyl + Suxamethonium (likely BP)

Microcuff ETT

Maintenance: Sedation/ NMB (avoid histamine releasing drugs)

A-line

IV fluids

Regular IV Hydrocortisone

MgSO4 to keep levels upper end normal

Physio and saline nebs

PRVC: Copes with changes in resistance/compliance and limits barotrauma

Cautious PEEP/ low tidal volume/ increased expiratory time

Permissive hypercapnoea/ accept pH ≥ 7.2

Vigilance for breath stacking/pneumothorax

OSA in Children

Definition:Episodic partial or complete airway obstruction during sleep, resulting in disrupted sleep and abnormal gas exchange.

Incidence:Affects 1-5% of children at any age, most common between 2-6 years

M:F 1:1 (changes post puberty 2M:1F by adulthood)

Risk factors:Adenotonsillar Hypertrophy

BMI (Hannon et al Jpaediatrics 2012 Adolescents with BMI >97th centile, 45% OSA on PSG)

Other Risk Factors

Craniofacial abnormalities (micrognathia, retrognathia, midface hypoplasia)

Neuromuscular disorders/CP (altered tone)

Macroglossia (mucopolysaccharidosis, Beckwith Wiedemann, hypothyroidism)

Downs (midface hypoplasia, macroglossia, reduced tone)

HbS

Sleep fragmentation

Intermittent hypoxia/elevated CO2

Increased work of breathing

Neuroapoptosis in developing brain

Reduced memory

Reduced learning performance

PAP (>35% with mod/severe OSA)

What’s the Problem?

Snoring Obstructive OSA

Hypoventilation

3-12% of children snore at night.

Presence of snoring not diagnostic of OSA

Absence of snoring can’t exclude OSA

(peak obstruction during REM sleep, when muscle tone is lowest. REM usually during final third of sleep when least likely to be observed by parent).

Snoring (loud, ≥3 night/week suspicious of OSA)

Witnessed apnoeasRestless sleep/night terrors/frequent waking/enuresisSweating Sleep position (side, neck flexion, AO extension)Daytime sleepiness (school, car journeys, reading, watching TV)Morning headaches/difficulty wakingInattention/poor concentration/behaviour problems/hyperactivity

Even well validated questionnaires are not reliable for diagnosis or exclusion of OSA (sensitivity & specificity 50-60%)

Audio/video recordings and overnight SaO2 all have low NPV (negative result insufficient to exclude OSA).

History

Measure

Oral and nasal airflowAbdominal/chest wall movementETCO2/transcutaneous CO2SaO2ECGSnore microphoneEEG/EMG (face/leg movement)

Electrooculography (detect eyes open/shut)

Has to be in a sleep lab, overnight and interpreted by specialist in sleep medicine

PolysomnographyGold Standard for

diagnosis/exclusion of OSA in infants/children/adults

AHI Severity SaO2 Nadir (no classification uniformly accepted) (92% lowest nadir in normal

sleeping children)

AHI: Number of apnoeas+hypopnoeas/hour of sleep recordedAHI ≥ 1 with relevant symptoms, diagnostic for OSA

Apnoea: >90% reduction in airflow lasting ≥90% duration of 2 breathsObstructive: inspiratory effort during reduced airflowCentral: no inspiratory effort during reduced airflow

Hypopnoea: ≥30% reduction in airflow lasting ≥90% duration of 2 breaths

Assoc. with arousal or transient SaO2 ≥3% Obstructive/ central/ mixed

Polysomnography (PSG) Report

Tonsillectomy alone less effective

Adenoidectomy alone not recommended for OSA management

Size of tonsils and adenoids does not correlate with presence/severity of OSA or response to resection

Obese/craniofacial abnormality/abnormal tone/severe OSA: less likely to normalise PSG, but AHI should decrease

FTT and PAP should resolve

Conflicting results as to whether school performance improves

Friedmann et al Otolarygology, Head and Neck surgery 2009(>1000 children 58.9% completely PSG after adenotonsillectomy)

Marcus et al NEJM 2013 (464 children 5-9 years, normal PSG 7 months later in 79% after adenotonsillectomy vs 46% without surgery)

First Line TreatmentAdenotonsillectomy +/- Weight

Optimisation

Preop Assessment:

History (sleep, current/recent RTi, comorbidity)

Examination (BMI, FTT, facial appearance, mouth/nasal breather, pectus excavatum)

Investigations (PSG)? Ward or HDU postop

Recognised Risk Factors of Respiratory Compromise Post Adenotonsillectomy

(Grade 1B)

Age <3 yearsSevere OSA on PSG (AHI ≥ 24/hr, SaO2 nadir ≤ 80%)Abnormal airway tone/structure (NM disease/craniofacial/BMI)FTTRecent RTiCardiac Complications of OSA (PHT, RVH)

Anaesthetic Management

Preop Analgesia: Paracetamol (15mg/kg)/Ibuprofen (10mg/kg)

Induction: Propofol 1%+Remifentanil (5mcg/ml) TCI

or

Propofol bolus + Remi bolus (2mcg/kg)

Maintenance: Propofol+Remi TCI

or

O2+N2O+Des

IV Hartmanns 10ml/kg bolus maintenance

Ondansatron (0.1mg/kg) + Dexamethasone (0.15mg/kg)

Morphine (25-100mcg/kg)

SaO2 monitoring for any child with OSA

Avoid supplementary O2

Analgesia * AVOIDING CODEINE*

IV fluid at maintenance rate till drinking well

Postop

Children having tonsillectomy will receive multimodal analgesia from their anaesthetist in theatre. Unless there are contraindications specific to an individual patient, for inpatient analgesia postoperatively the anaesthetist will prescribe:

Paracetamol 15mg/kg 4 hourly PRN

Ibuprofen 10mg/kg 6 hourly PRN

Morphine solution 100-300 micrograms/kg 2 hourly PRN (maximum 6 doses in 24 hours)

(maximum per dose 10mg)

In line with recent recommendations from the MHRA and the APA (Association of Paediatric Anaesthetists) no children having tonsillectomy should receive Codeine postoperatively, either in hospital or at home.

Post op Analgesia in Hospital

For discharge home these children should be prescribed:

Paracetamol as per discharge analgesia guidelines

Ibuprofen as per discharge analgesia guidelines

Morphine Solution 200micrograms/kg (maximum per dose 10mg)

3 postoperative doses to be given on the mornings of day 3, day 4 and day 5 (day of surgery being day 0). For children below 2 years please seek Pain Team advice.

On discharge home please ensure parents receive a copy of the Parent Information Leaflet ‘Pain Relief after Tonsillectomy’. This provides guidance on giving children regular pain relief post tonsillectomy, the signs to look out for in children receiving opioid medications and when to seek medical attention.

Analgesia Post Adenoidectomy

Children having adenoidectomy alone will receive multimodal analgesia from their anaesthetist in theatre.

In line with recent recommendations from the MHRA and the APA (Association of Paediatric Anaesthetists) no children having adenoidectomy should receive Codeine postoperatively, either in hospital or at home.

For these children paracetamol and ibuprofen postoperatively on the ward and for discharge home should be sufficient.

Guideline for Postop Monitoring of Patients with OSA 

This includes a spectrum of patients, ranging from mild through moderate to severe OSA. Excluding those with severe OSA, or those with significant co-morbidity (listed below), the majority of patients should be able to return to ward 3 postoperatively. 

Mild, Mild/Moderate, Moderate or Moderate/Severe OSA with SaO2 ≥ 60% on Sleep Study

 Return to a monitored bed on ward 3 opposite the nurse’s station, to facilitate close observation. SaO2 should be monitored during all periods of sleep until achieve restful sleep with SaO2 ≥ 90% overnight.If SaO2 < 90% on air, over a 5 minute period despite repositioning, the anaesthetist and surgeon involved in the case should be contacted. If this occurs out of hours the PICU fellow and PICU Band 7 should be contacted. If PET criteria are met a PET call should be activated.In this patient group the most likely cause of desaturation is airway obstruction, therefore managing desaturations with supplementary O2 alone is not appropriate.Noisy breathing or restlessness during sleep are also signs of airway obstruction and warrant review.Patient transfer from ward 3 to HDU requires Consultant to Consultant referral, therefore both the on call PICU consultant and ENT consultant should be informed.

 

Severe OSA with SaO2 < 60% on sleep study, or any grade of OSA plus significant comorbidity including: Downs,

craniofacial anomalies, age ≤ 2years, neuromuscular disorders, obesity

 

Should consider postop admission to HDU under PICU care, for at least the first postop night. This patient group usually come from, and therefore return to, the care of the respiratory team on ward 1 following discharge from HDU.

 

Postop management may vary from this guideline at the discretion of the anaesthetist or surgeon if there are airway concerns during induction, emergence or in recovery.

HDU admission under PICU care is mandatory for patients: With adenoidal packs in situ

Requiring an NPAFollowing removal of an NPA patients must remain on HDU under PICU care until they maintain SaO2 ≥ 90% during sleep. They can then return to a monitored bed on ward 3, where SaO2 should be monitored during sleep for a further 24 hours at least.

  

Referral to the Respiratory team is appropriate for patients who > 2 days postop:

 Have noisy breathing awakeHave signs of increased respiratory effortAre restlessness with noisy breathing during sleepHave SaO2 < 90% on air with witnessed obstructive episodes  

Management of Children with RTi

Management of Children with Acute Severe Asthma

Management of Children with OSA

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