1. Acute severe bronchialAcute severe bronchial
asthmaasthma
Presented by:Presented by:
Reem alsafar.Reem alsafar.

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

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

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

5. Classification:Classification:
Diagnosis ofDiagnosis of
asthmaasthma
DayDay
symptomssymptoms
NightNight
symptomssymptoms
%personal%personal
best PEF orbest PEF or
FEV1FEV1
MildMild
intermittedintermitted
≤≤22 times per weektimes per week
with briefwith brief
exacerbationsexacerbations
<2<2times pertimes per
monthmonth
No daily med. neededNo daily med. needed
≥≥80%80% .asympt..asympt.
With normal LFWith normal LF
bet. exacerbationbet. exacerbation
MildMild
persistentpersistent
>2>2times per week,times per week,
but not more thanbut not more than
once adayonce aday
>2>2times pertimes per
month /exaceb.month /exaceb.
affect activity andaffect activity and
sleep .sleep .
<80%<80%
ModerateModerate
persistentpersistent
DailyDaily withwith
exacerbation affectexacerbation affect
activity and sleepactivity and sleep
>1>1 time pertime per
weekweek
>60-<80>60-<80
SevereSevere
persistentpersistent
continualcontinual Frequent withFrequent with
freq.freq.
exacerbationexacerbation
≤≤60%60%

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

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

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

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

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

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

12. -Add ipratropium 0.5mg to nebulized-Add ipratropium 0.5mg to nebulized ββ--
agonist.agonist.
-Give aminophilline IV 250mg (5mg/kg) over-Give aminophilline IV 250mg (5mg/kg) over
20 min. omit this bolus if patient is on oral20 min. omit this bolus if patient is on oral
theophlline but urgently check level oftheophlline but urgently check level of
therapeutic . Alternatively ,give salbutamoltherapeutic . Alternatively ,give salbutamol
or terbutaline 0.25mg IV over 10 min.or terbutaline 0.25mg IV over 10 min.

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

14. Further managementFurther management..
If patient improving:If patient improving:
--40-60%40-60%O2 + prednisolone 30-60mg/24hO2 + prednisolone 30-60mg/24h
popo..
--Nebulized salbutamol every 4hNebulized salbutamol every 4h..
-Monitor peak flow and oxygen-Monitor peak flow and oxygen
saturations.saturations.

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

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

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

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

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

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

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

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

23. References:References:
1-Davidson`s Principles and Practice of Medicine, text1-Davidson`s Principles and Practice of Medicine, text
book, 19book, 19thth
edition.edition.
2-Parveen Kumar and Michael Clark. Clinical Medicine2-Parveen Kumar and Michael Clark. Clinical Medicine
text book, 5text book, 5thth
edition.edition.
3-Oxford Hand Book of Clinical Medicine ,43-Oxford Hand Book of Clinical Medicine ,4thth
edition.edition.
4-250 cases in clinical medicine, R.R.Baliga ,3th4-250 cases in clinical medicine, R.R.Baliga ,3th
edition.edition.
5-5-
http:/www.tsged.com/Newsletters/Asthma_Emergencihttp:/www.tsged.com/Newsletters/Asthma_Emergenci
es. Htm.es. Htm.
6-Hospital In Patient Management of Acute Asthma6-Hospital In Patient Management of Acute Asthma
Attacks ,A National Clinical Guidelines recommendedAttacks ,A National Clinical Guidelines recommended
for use in Scotland by Scttish Intercollegiatefor use in Scotland by Scttish Intercollegiate
Guidelines Network, Pilot Edition 1996Guidelines Network, Pilot Edition 1996