The Respiratory System

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Dr AE Kappos

Pulmonology

RCWMCH

15 Feb 2012

� Respiratory illness is very important

� Major cause of death in childhood

� Most common cause of acute and chronic illness

� May also lead to permanent impairment of lung function and to chronic lung disease even into adulthood

Cough

� Most important DEFENCE mechanism of the body

� Cough is our own personal physiotherapist

� Most common presenting symptom of resp illness

� INABILITY TO COUGH IS AN EMERGENCY

� Cough suppression is CONTRAINDICATED

IN CHILDREN UNDER 4 YRS (ESP <2 MONTHS)

Cough continued

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� Persistent cough of >3 weeks with constitutional symptoms of weight loss and fever:RED FLAG for TB

� “Barking cough,honking cough”:CROUP

� “Whooping cough”:pertussis

Tachypnoea

� Fever

� Pneumonia

� Anxiety

� Pain

� Dehydration (acidotic breathing/kussmaul breathing)

� Lung Congestion (left to right cardiac shunts)

� Pulmonary oedema

� Severe anaemia, salicylate poisoning

Respiratory rate limits

� <2 months: 60 breaths/min

� 2-12 months: 50 breaths/min

� 1-5 years:40 breaths/min

Signs of respiratory distress

� Tachypnoea with Lower chest retractions

� Nasal flaring( severe distress)

� Resp failure: grunting, cyanosis , depressed level of consciousness

Risk factors for severe acute resp infection

� MEDICAL: <1 YR,Prem, Immunosuppresion

� SOCIAL: overcrowding,passive smoking,inadequate housing,indoor fuel exposure

� NUTRITIONAL: Malnutrition, lack of breastfeeding

Oxygen delivery methods

� Humidified low flow oxygen (0.5-3l/min) applied via NP02 is usually sufficient for hypoxic children( delivers 28-35% o2)

� Headbox oxygen can be an alternative(does not

require humidification but wastage and feeding can be problematic, FI02 delivery is unpredictable)

� Facemask oxygen delivery 28-65% at flow rate 6-10l/min for children, not tolerated very well by infants

� IN SEVERE HYPOXIA:use polymask (60-80% )

Noisy breathing

� Implies obstruction

� NB in diagnosis is pinpointing the site of obstruction and not labeling the noise as stridor/wheeze etc

� The kind and loudness of noise is NOT helpful

Noises according to site of obstruction

STRIDOR WHEEZE

Nasopharynx/throat + 0

Larynx + +

Trachea /bronchi + +

Peripheral airways 0 +

Sites of obstruction

SITE COMMON CAUSES

Extrathoracic

1.Nose and nasopharynx Coryza, sdb

2.Larynx CROUP,Laryngomalacia

Intrathoracic

3.Trachea /bronchi Vascular ring,TB nodal compression,foreign body

4.Peripheral airways Asthma,bronchiolitis,BPN,CF,Aspiration syndromes,GOR,Chronic HIV lung disease

Identifying the site of obstruction

� Three questions:

� Inspiration or expiration?

� If in inspiration, is the obstruction present during mouth breathing?

� If it is in expiration, is there air trapping present?

Common resp conditions

� LARYNGOMALACIA

� Commonest cause of noisy breathing in neonates

� Inspiratory noise starting from birth or usually from day 10 of life

� Variability of obstruction with posture and breath

� NO EXPIRATORY COMPONENT

Laryngomalacia

Laryngomalacia

� Simple: larynx structurally normal

Laxity of supraglottic tissues that are sucked into the lumen of larynx with inspiration

� Resolves by 1 yr of age

� Complex : Above symptoms with difficult drinking,dysphagia,laryngeal incompetence with pulmonary aspiration ,vocal cord paralysis

� May ameliorate with growth but does not resolve totally

Laryngomalacia

� Investigations: Laryngoscopy

Barium swallow if indicated

� Management: REASSURANCE Mostly

GOR treatment if present

Laser excision of excess supraglottic tissue for severe obstruction

Tracheostomy in some complex cases

Bronchiolitis

� Most common cause of severe acute viral LRTI in children< 2yrs

� Usually caused by RSV /Rhinovirus

� Highly infectious

� Affects the peripheral airways causing BAT and often wheeze

� Airway obstruction is due to inflammation and edema and not muscle constriction

� Spreads via contaminated hands

Bronchiolitis risk factors

� HOST FACTORS: prematurity, congenital heart disease, CLD of prematurity, neurological disease, infants<6months, immune deficiency,lack of breastfeeding

� ENVIROMENTAL: Poverty, overcrowding,passive smoke exposure, Day Care attendance

Bronchiolitis Prevention

� Avoid exposure to children and adults with colds

� Frequent hand washing

� Passive immunization with Palivizumab for premature infants and in infants with CLD and congenital heart disease (expensive and needs to be given monthly during RSV season)

� RSV Season CT: rainy season and between autumn and winter

Gauteng: Late Feb-August

KZN: Feb-March (rainy season)

Bronchiolitis Symptoms

� History of 1-2 days of URTI symptoms of nasal congestion

� with progressive tachypnoea

� Seasonality

Bronchiolitis signs

� Bilateral wheezing (and crackles)

� Bilateral air trapping with peripheral airways obstruction seen with Hoover sign and resonance with percussion over heart and upper border of liver

� Tachypnoea

� Downward displacement of liver and spleen because of hyperinflation (BAT)

Bronchiolitis diagnosis

� Clinical diagnosis based on history and clinical examination ONLY

� No CXR warranted unless diagnosis doubtful and/or constitutional signs present

� No indication for CRP

� Oxygen sats in room air is important

� Bronchodilator response test(most do not response but some do)

Bronchiolitis indications for hospitalization

� Oxygen sats <90% (inland), <92% (coast)

� Severe respiratory distress/failure(grunting,cyanosis,nasal flaring)

� Poor feeding

� Apnoea

� Prem infants with risk factors

� Underlying medical condition(Congenital heart disease,CLD,Down syndrome)

� Severe malnutrition

Admission pre-requisites

� Nurse alone in a cubicle (ie “in isolation”)

� Or COHORT with children >2 yrs of age and no underlying risk factor for severe illness

Bronchiolitis treatment

� No medications indicated for children not requiring hospital admission

� THE OBJECTIVE FOR HOSPITALIZATION IS TO MAINTAIN HYDRATION AND OXYGENATION thus

� Feeding: if unable to feed ,feed via NG tube (small frequent feeds to avoid overdistention)

� Humidified low-flow oxygen (0,5-3l/minute) VIA NASAL prongs (28-35%) is usually sufficient in hypoxic children

Bronchiolitis treatment cont.

� Antibiotics not indicated unless severe cases,requiring ICU admission, nosocomial acquisition of RSV or cyanotic congenital heart disease,immune deficiency to cover for bacterial co-infection

� Bronchodilator therapy is not routinely recommended but if infants respond can be continued until symptoms improve

� Hypertonic saline 3% nebs has shown benefit (ideal dosage not confirmed, can be given 2-6 hr)

Bronchiolitis treatment NOT INDICATED

� Do not give ADRENALINE

� Do not give ICS or oral steroids

� Do not do chest physiotherapy

� Do not institute regular suctioning

Bronchiolitis discharge and follow up

� Discharge when drinking well and oxygen saturation is > 92% in room air

� Some tachypnoea,air trapping and crackels may persist for up to 4 weeks

� Review at outpatients 6-8 weeks after discharge by which time all airtrapping should have resolved.If still BAT consider:New infx,CF or GOR with micro-aspiration

� Warn parents about post bronchiolitis wheezing

CROUP

� Pediatric equivalent of adult acute laryngitis

� Clinical features:

� Previously well, immunized against diptheria,initially runny nose, cough and difficult noisy breathing (inspiratory stridor) and chest retractions

� Peak incidence at 2 yrs with occurrence from 4months to 4 yrs

Features that are NOT CROUP

FEATURES CONDITION

Sudden onset, very severe obstruction Foreign body

<4 months Subglottic stenosis(congenital)

Incomplete immunization Diptheria

Severe oral thrush Candida laryngitis

Fever, erythema Staph tracheitis

Fever, sore throat,DROOLING,DYSPHAGIA

Epiglottitis, retropharyngeal/peritonsilar ascess

Aphonia, previously hoarse Laryngeal papillomatosis

CROUP diagnosis

� Record oxygen saturations (sats<92% is uncommon and should warrant a re-evaluation of diagnosis)

� Blood gases are unhelpful and unnecessary

� X-ray confirmation only indicated if atypical features present:

� Steeple sign of AP neck view is diagnostic of subglottic narrowing

Normal AP view of neck

“Steeple sign”

Severity of CROUP

� TREATMENT DEPENDS ON THE SEVERITY OF THE AIRWAY OBSTRUCTION and not on the noise (stridor)

� THE GRADING IS THAT OF THE AIRWAY OBSTRUCTION and not the intensity of the stridor, as that gets softer as obstruction increases!!!!!!!!!

Grading Criteria

� Inspiratory obstruction: inspiratory noise (stridor), retractions, tracheal tug

� Expiratory obstruction: visible or palpable contraction of rectus abdominal muscles during expiration

� Pulsus paradoxus: pulse becomes weak or disappears with inspiration

GRADES OF OBSTRUCTION

GRADE INSPIRATORY OBSTRUCTION

EXPIRATORY OBSTRUCTION

PULSUS PARADOXUS

I +

II + +

III + + +

IV Extremis,marked retractions,apathy,cyanosis

Treatment� All grades of obstruction get

CORTICOSTEROIDS (on diagnosis)

� Prednisone 2mg/kg stat ORALLY

� Dose can be repeated in 24 hours

� (In severely ill children who are unable to swallow one can consider giving ivi Dex 0,6mg/kg stat- in extreme situations only)

� If airway obstruction is worse 4 hours after steroids, diagnosis should be reviewed

� Steroids are CONTRA-INDICATED in measles-in such instances intubate if warranted

Treatment

� Grade 1: can be sent home after stat dose pred with advice to return if worsening symptoms

� Grade 2: Admit, monitor sats, check degree of obstruction 3 hourly

� Give adrenalin nebs (in conjuction with steroids)half hourly

� Comfort child

� Avoid noxious stimuli

� Continue normal feeds

Treatment

� Grade 3 and Grade 4

� LIFE THREATENING

� ADMIT TO ICU

� CONTINUOUS ADRENALINE NEBS WITH OXYGEN

� IF 6 HRS AFTER STEROIDS, STILL > GRADE 3 OBSTRUCTION, ENDOTRACHEAL INTUBATION IS INDICATED

Discharge and follow up

� Stop nebs when obstruction is grade 1

� Can be discharged 6-8 hrs after last neb

� Routine post croup follow up is not indicated

� Can recur but seldom needs hospitalization\

� Recurrences requiring hospitalization need to be referred

Pneumonia: cough and a clinical sign

CLINICAL SIGN PNEUMONIA CATEGORY MANAGEMENT

Lower chest indrawing Severe pneumonia First dose ivi/im antibiotic, hospital referral

Tachypnoea Pneumonia Oral antibiotic

No tachypnoea/lower chest indrawing

No pneumonia Supportive treatment

GAAP

Admission Criteria

Treatment

� Oxygen via nasal cannula, face mask or head box if saturations are <92%

� No difference between different modes of oxygen delivery as long as sats >92%

� IVI fluids and electrolyte testing only in children that are vomiting or severely ill

AGE AMBULENT HOSPITALIZED

0-2 MONTHS RECOMMEND ADMISSION

AMPICILLIN/PENICILLIN IVI + AMINOGLYCOSIDE(CEFTRIAXONE/CEFOTAXIME IVI)

>2 MONTHS-5 YRS HIGH DOSE ORAL AMOXYL (30MG/KG/DOSE TDS)

IVI AMPI/HIGH DOSE AMOXYL (IVI CEFUROXIME.AUGMENTINOR IVI CEFTRIAXONE/CEFOTAXIME

> 5YRS Amoxycillin po high doseORMacrolide if suspect Mycoplasma/Chlamydia

As above

Treatment continued

� Add aminoglycoside at any age if HIV infected or if severely malnourished

� Add macrolide if Chlamydia suspected in <6 months

� Add cloxacillin if fail to respond to treatment after 48 hours (especially > 2 months of age) or CXR changes suggesting empyema,pneumatocele or abscess

� Add Macrolide in >5yrs if no response after 48 hrs on treatment and/or wheezing

� Treat generally 5-7 days with antibiotics

WHO recommendations in HIV infected children

Pneumonia prevention

� Immunization(esp Measles,pneumococcal)

� Vitamin A

� Zinc supplementation esp in malnourished pts

� Nutrition(continued breastfeeding)

� Avoiding passive smoke exposure

� Preventing TB

� Preventing ARI in HIV infected children (cotrimoxazole prophylaxis)

Sleep Disordered Breathing

� Upper airway obstruction during sleep

� Mild to severe airway obstruction with intermittent totally obstructed episodes during sleep

� The question to ask each parent is: “is the child SNORING?” at routine child care visits

Adverse Effects of SDB

Fragmented sleep******* asphyxia Negative pleural pressure

Developmental delay: DEATH Aspiration pneumonia

Failure to thrive near-SIDS “Bronchitis”

Learning difficulties PERMANENT CNS DAMAGE

Chest deformity

Behavioural problems Cardiac arrhythmia Pulmonary oedema

Pathological shyness Pulmonary hypertension

Morning headaches Congestive heart failure

Restless sleep (enuresis,sleep walking,nightmares)

Systemic hypertension

DAYTIME sleepyness

Diagnosis� History: snoring and/or disturbed sleep

� Cell phone video of child sleeping

� No special investigation is necessary to prove dx or assess severity

� Rare cases where diagnosis is doubtful can admit for overnight/sleeping sats

� SNORING IS COMMON thus isolated snoring for <3 months is usually benign

� ABSENCE OF DAYTIME SYMPTOMS,NORMAL EXAM does not exclude SDB

Diagnosis continued

� Examination: usually normal, although severely affected children may have snoring sounds and mouth breathing even when awake.

� LOOK for evidence of FTT, pulmonary hypertension

� When asleep: noisy breathing and increased respiratory efforts

� Special investigations:

� X-ray of postnasal space for adenoidal tissue

Post nasal space X-ray

Diagnosis continued

� FBC : polycythaemia (very rare)

� ECG and cardiac echo insensitive guide to the severity of SDB(only a 1/3 of patients with severe obstruction have pulmonary hypertension)

Treatment

� Treat allergic rhinitis

� Adenoidectomy: snoring >4 months despite medical treatment

snoring with TOES/cyanosis

complications

adenoidal tissue on x-ray/endoscopy

� Tracheostomy if associated with anatomical abnormality of nose /pharyngeal airway

� CIP tube for life-threatening obstruction