acute bronchial asthama in newborn management of new born disrder in new born

1. Acute severe bronchial
asthma
Presented by:
Reem alsafar.

2. Bronchial asthma:
Chronic airflow limitation witch is usually
reverses spontaneously or with treatment ,due
to airway hyper-responsiveness to a range of
specific and nonspecific stimuli (e.g exercise
,cold air) and inflammation of the bronchi
(esonophils , lymphocytes, mast cells ,neunt.,
associated edema , smooth muscle hypertrophy
and hyperplasia, thickening of basement
membrane ,mucous plugging and epithelial
damage.

3. Epidemiology:
The prevalence of asthma is increasing in 2nd decade of
life with highest rates in New Zealand, Australia and UK
, and lowest in china and Malaysia.
Etiology:
There are 2 major factors involved in the development of
asthma:
- atopy (production of large amount of IgE on exposure
to small amount of common antigen wich can be idetified
by skin prick reactions
- non-atopy or intrinsic asthma (increased
responsiveness of the airways of the lungs as measured
by a fall in FEV1 to stimuli e.g: histamine , methacholine.
Almost all asthmatic patients show some degree of
atopy.

4. Pathogenesis:
Is complex and not fully understood .
It involves a number of cells ,mediators ,nerves and vascular
leakage witch can be activated by several mechanism ,of witch
exposure to allergens is the most relevant.
Precipitating factors:
-genetic susceptibility: genetic contribution to asthma remains poorly
defined ,it possibly involves polygenic inheritance and genetic heterogenesity
where different combinations of gens leads to asthma in different individuals.
-environmental factors:house dust mites ,pets, fungul spores ,nitrogen
and sulfer dioxide, grass and flower pollens and climate.
-infections.
-drugs.
-smoking -emotions -exercise

5. Classification:
%personal
best PEF or
FEV1
Night
symptoms
Day
symptoms
Diagnosis of
asthma
≥80% .asympt.
With normal LF
bet. exacerbation
<2times per
month
No daily med. needed
≤2 times per week
with brief
exacerbations
Mild
intermitted
<80%
>2times per
month /exaceb.
affect activity and
sleep .
>2times per week,
but not more than
once aday
Mild
persistent
>60-<80
>1 time per
week
Daily with
exacerbation affect
activity and sleep
Moderate
persistent
≤60%
Frequent with
freq.
continual
Severe
persistent

6. Severe acute asthma
Is a medical emergency characterized by
severe progressive asthmatic symptoms
over a number of hours or days that must
be recognized and treated immediately.

7. Presentation: acute breathlessness and
wheeze, patients are usually extremely
distressed , using accessory muscles of
respiration ,are hyper-inflated and tachypnoeic
accompanied by tachycardia, pulsus
paradoxus and sweating .
In very severe cases central cyanosis occurs
and airflow may have become so restrictive
that rhonchi are no longer produced.
The presence of silent chest and bradychardia
in such patients is an ominous sign.

8. In the history:
Ask about usual and recent treatment
,previous acute episodes and their severity ,
have they been admitted to ITU.
Other conditions in witch wheeze is
prominent sign:
Acute infective exacerbation of COPD,
pulmonary oedema, URT obstruction,
recurrent thromboembolism, tumor causing
localized wheeze.

9. Immediate management
Assess severity of the attack:
In severe attack:
-the patient is unable to complete
sentences
-RR>25 BPM.
-PR >110 beat/min .
-PEF<50%of predicted or best.

10. Start treatment immediately prior to
investigation.
-Sit up and give O2 in high dose 60%.
-salbutamol 5 mg or terbutaline 10 mg
nebulized in O2.
-hydrocortisone 200 mg IV or prednisolone
30mg PO or both if very ill.
-antibiotics if definite evidence of infection:
Focal shadowing on chest x ray, purulent
sputum
-chest x ray to exclude pnumothorax or
pneumonia.

11. If life threatening features are present:
Which are:
-PEF<33% of predicted or best.
- silent chest, cyanosis feeble respiratory
effort.
-bradycardia or hypotention.
-exhaustion, confusion or coma.
-ABG: PaCO2 >5Pa (36mmHg)
,PaO2<8Pa(60mmHg) ,low pH <7.35.

12. -Add ipratropium 0.5mg to nebulized β-
agonist.
-Give aminophilline IV 250mg (5mg/kg) over
20 min. omit this bolus if patient is on oral
theophlline but urgently check level of
therapeutic . Alternatively ,give salbutamol
or terbutaline 0.25mg IV over 10 min.

13. Monitoring the effects of treatment.
-Repeat PEFR 15-30 min after initiating
treatment and then pre and post β-agonist
in hospital at least four times.
- Pulse oximeter monitoring: maintain
SaO2>92%.
Check blood gases only if SPO2<92% or
life threatening features.
-consider repeat blood gases 2h after
starting treatment.
-daily U/E as steriods and salbutamol may
result in hypoklaemia

14. Further management.
If patient improving:
-40-60% O2 + prednisolone 30-60mg/24h
po.
-Nebulized salbutamol every 4h.
-Monitor peak flow and oxygen saturations.

15. If patient not improving after 15-30
minutes.
-Continue 60% O2 and steroids.
-Nebulized salbutamol, max every 15-30
min.
-Ipratropium 0.5mg nebulized every 6h.

16. If patient still not improving.
-Aminophylline infusion-adult:
500mcg/kg/h , in 10-16y 800mcg/kg/h.
-Do levels if infusion lasts >24h.
Alternatively, give salbutamol infusion, eg
3-20mcg/min.
-If no improvement, or life-threatening
features present, consider transfer to ITU.
Patient must be accompanied by an
anesthetist prepared for emergency
intubation.

17. once patient improving
-Wean down and stop aminophylline over 12-
24h.
-Reduce nebulized salbutamol and switch to -
inhaled β-agonist.
-Initiate inhaled steroids and stop oral
steroids if possible.
-Continue to monitor PEFR. Look for
deterioration on reduced treatment and
beware early morning dips in PEFR
-Look for the cause of the acute exacerbation
and admission.

18. Drugs used in acute asthma.
Aminophylline: The amount of IV
aminophylline may need altering
according to the individual. Factors which
may necessitate reduction of dose:
Cardiac or liver failure, drugs which
increase the half-life of aminophylline eg
cimetidine, ciprofloxacin, erythromycin,
propranolol, contraceptive steroids

19. Factors which may require to increase the
dose: Smoking drugs which shorten the half-life,
eg: phenytoin, carbamazepine, barbiturates,
rifampicin.
Aim for plasma concentration of 10-20mcg/mL
(55-110 ml mol/L. serious toxicity (BP increase,
arrhythmias, cardiac arrest) can occur at
concentrations ≥25mcg/mL.
Measure plasma K+.
Salbutamol side effects: Tachycardia,
arrhythmias, tremor, hypokalaemia.

20. On discharge, patients should have:
-Been on discharge medication for 24h.
-had inhaler technique checked.
- Peak flow rate >75% predicated or best
with diurnal variability <25% steroid and
bronchodilator therapy.
-Own PEF meter and management plan.
-GP appointment within 1 week.
-respiratory clinic appointment within 4
weeks

21. What are the indications for mechanical
ventilation with intermittent positive
pressure ventilation?
-Worsening hypoxia (PaO2 <8kPa) despite
60% inspired oxygen.
-Hypercapnia (PaCO2 >6kPa).
-Drowsiness.
-Unconsciousness.

22. What are the indications for steroids in
chronic asthma?
-Sleep is disturbed by wheeze.
-Morning tightness persists until midday.
-Symptoms and peak expiratory flows -
progressively deteriorate each day.
-Maximum treatment with bronchodilators.
-Emergency nebulizers are needed.

23. References:
1-Davidson`s Principles and Practice of Medicine, text
book, 19th edition.
2-Parveen Kumar and Michael Clark. Clinical Medicine
text book, 5th edition.
3-Oxford Hand Book of Clinical Medicine ,4th edition.
4-250 cases in clinical medicine, R.R.Baliga ,3th
edition.
5-
http:/www.tsged.com/Newsletters/Asthma_Emergenci
es. Htm.
6-Hospital In Patient Management of Acute Asthma
Attacks ,A National Clinical Guidelines recommended
for use in Scotland by Scttish Intercollegiate
Guidelines Network, Pilot Edition 1996