Management of Status Asthmaticus

Management of Status Asthmaticus

Dr. Nasser HaidarMBBS, ABMS, KSUF, MRCP (UK), FPCCM

Senior Consultant Pediatric Critical Care

Associate Professor ; UST, Sanaahaidarnaa@yahoo.com

الرحمن الله بسمالرحيم

Introduction

• Definition.• Epidemiology.• Pathophysiology

• Recognition.

• Management.

• Questions• Summary

What is Status Asthmaticus ?

Wheezing not responding to the

initial doses of nebulized bronchodilators

No specific definition

How big is the problem?

Hospital Admissions 500,000 (200,000)

Needed Intubation 1 – 20%

DeathsUp to 8% of MV

5000 / Year

Prevalence 10-30%

Hospitalization

Hospitalization

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

0

10

20

30

40

50

60

70

< 1 year

1­4 years

5­14 years

15­24 years

Rat

e pe

r 10

,000

 pop

ulat

ion

Hospital discharge rates for asthma

MMWR 1996;45(17):350-3

Mortality

Rates of death in children from asthma

Mannino. MMWR 1998;47(1):1-27

More in adults More in children

< 4 Y

< 4 Y

Adults

15-24

Risk factors for fatal asthmaDifficult to

identifyHistory ofED visitsIntubation/ventilation Psychosocial issuesNon-whiteObesityGenetic (response)

http://www.nhlbi.nih.gov/guidelines/asthma/asthgdln.pdf

1/3 of deaths had only

mild asthma

Pathophysiology

Lazaar AL. Am J Med 2003;115:652, with modification

Airway remodelingEpith. injury

Subepith. fibrosis

Smooth muscle

hyperplasia

Mucous gland

hypertrophy

Goblet cell

hyperplasia

Mucus

Airway remodeling

Broncho-constriction with allergen challenge

Broncho-constriction with allergen challenge

Before

10 Minutes After

Allergen Challenge

Inflammation

Airway edema

Mucous blug

Spasm

Narrow airway

Premature closure

Air trapping Heterogene

ousV/Q mismatch

Hypoxemia

Hypercarpia

Sequence of Events

Dead space

Hypoxemia

Acidosis.

VC-Ve I.P. P.

LV

P. edema

Hyperinflation.

RV

Hypotension

Cardiopulmonary Interaction

Presentation &

Assessment of Severity

Presentation

Impending RF

Altered LOC Central cyanosis

Distant or absent breath sounds

Agitation or inability to lie down

Inability to speak, Sweating

Work of breathing Wheezing

Resp.Failure

Assessment of

Severity

Score RR Wheezing I:e ratio

Accessory

muscles.

Saturation.

0 ≤ 30 None 2:1 None 99-1001 31-45 End

Expiration

1:1 + 96-98

2 46-60 Entire Expiratio

n

1:2 ++ 93-95

3 >60 Inspiration Expiration

1:3 +++ <93

Pulmonary Index Score

≥ 5 Impending Resp. failure

Pulsus Paradoxus

Normal Drop in BP

during inspiration

Is ≤5

≥10 mmHg

Is PP

Capacitance of lung vessels.

LV afterload

Decr. C.O.

blood to LV

SV

Low BP

Peak Flow Rate

% State80 Normal70-80 Mild40-69 Mod.

<40 Severe

Age & Sex dependent

Assessment

Pulsus Paradox

us.

Clinical

Clinical

ClinicalPulmonar

y Index Score

Time consuming

PFR < 40%

(Cooperation)

Assessment

ABGBefore Beta2

agonist Respiratory Acidosis alone is not

Indication for intubation

Capnogram: NO Plateau

PreventionEducation

Early recognition.

Inhaler addictionSteroid phobia

Health System

Access

Aggressive

Correct use of inhalers

Treatment

General Supportive Measures

Not < 10-12 L/min

Euovolemia

Specific treatment

Nebulized Salbutamol

0.15 mg/kg

Minim. 2.5mg

Maxim. 5 mg

10 mg/h for 5-10 Kg

15 mg/h 10-20 Kg

20 mg/h > 20 Kg

Intermittent Continuous

Systematic Review

More effectiveNo extra S/E

10%10%0.15-0.5

mg/kg/hour

Steroids

Fanta CH: Am J Med 1983;74:845

Systemic Corticosteroids

Hydrocortisone4 mg/kg

2-4 mg/kg/dose

Optimal duration??????

Recent RCT 3 = 5 days

5-7 days for severe asthma

Methylprednisolone

2 mg/kg 0.5-1mg/kg/doseMeta-analysis No benefit with

higher doseActive or recent

exposure to chickenpox

Ibratropium bromide (Atrovent)

250 micg. for

< 20 Kg or < 6 Y

Then 500 micg.

Meta. 8 Ped. RCT Multiple doses decrease admission

by 25% (NNT = 4)Shorten Stay

Prolong duration of

Beta-2 agonist

Magnesium Sulfate

25-75 mg/kg over 20 minutes, max 2 g. Level

Meta. 5 Ped RCTDecr. Admissions

NNT = 4

Meta. Confirmed Efficacy & Safety

Meta. Adult. Inhaled MgSO4

Effective in severe cases

0

10

20

30

40

50

60

50 min 80 min 110 min

PlaceboMagnesium

Ciarallo L. J Pediatr 1996;129(6):809-14

Magnesium Sulfate

Salb

utam

ol

Nebul

izatio

n

Ibra

tropi

um

brom

ide

Mag

nesium

Sulfa

te

Ster

oidsWhat is next if no

improvement?

Parenteral Bronchodilators

Beta.2 Agonists OR

Aminophylline

Parenteral Bronchodilators

10 mcg/kg loading

0.1-10 mcg/kg/min

By 0.5 mic Q 30 min.

Bolus 15 mic/kg

OR

0.5-5 mcg/kg/min

Terbutaline Salbutamol

(Albuterol)

Better affinity

OR

AminophyllineMeta. 7 Ped. RCT

Improvement in clinical & PFT3 Ped RCT 30% Reduction in hospital

stay.Therapeuti

cLevel 10-20

mcg/ml

Side effects> 15

mcg/ml

Serious S/E

≥ 30

Achieve improvement or

Level of 15 mic/ml

Ove

rla

p

Contraindications of Theophylline

• Uncontrolled arrythmias• Uncontrolled Seizures• Peptic ulcer• Hyperthyroidism

Summary of Evidence

Therapy Strength of Recommenda

tion

Quality of Evidence

Short acting Beta2 a. Strong High

Systemic steroids Strong High

Magnesium sulf. Strong High

Anticholinergic Strong Moderate

IV Salbutamol Strong Moderate

Aminophylline Strong Moderate

Hypoxic orHypercarpi

a

Progressing

toward fatigue

Salb

uta

mol

Ibra

trop

ium

brom

ide

Mag

nesi

um

Sulfat

ePa

rent

eral

Bro

ncho

dila

tors

Amin

ophy

lline

Ster

oidsWhat is next?

You have to go through the difficult road

Positive Pressure

Ventilation

None Invasive Positive Pressure Ventilation

(NPPV)

NPPVSat. > 92% FiO2 <

70%PaCO2 < 45-50

mmHg

FiO2 > 70%PaCO2 > 50

mmHg

CPAP BiPAP8/5 12/8

Can NPPV be Applied to ALL

Patients?

NOCooperation Well fitted

mask

If NPPV Not suitable

or Failed !

Indications for Tracheal Intubation

Severe Hypoxemia

Severe WOB,

unable to speak, fatigue

Drop in LOC

Arrest

BUT

Be Ready with:

AdequateVenous access

Mon

itorin

gSedation

Able to manage DOPE &

Hypotension

Complications

10-50%

Goals of MVWOBAdequate

Oxygenation

Sufficient

Ventilation

PEEP

PRVCTV => plateau

<30Low rateLow Ti

I:e ratio 1:3-1:5High FR

Adjunctive Therapy“Rescue Therapy”

Cast

Adjunctive Therapy“Rescue Therapy”

Inha.GA ECMO

Propo

fol

Halothane or Isoflurane ?

Complications

Prognosis

MR Up to 8%

Of Intubated pts

QuestionsBefore the summary

Antibiotics

Bacterial or

Mycoplasma .

?

Heliox ?

• Meta. 3 Ped. RCT• Potential benefit• Facilitate drug delivery• Still not standard.

Leukotriene receptors

antagonists

Are you Going to Intubate

A child with:High respiratory effort.

Saturation 92%

PaCO2 55

pH 7.25

Unilaterally

dilated pupil!

Summary

If no response to first doses of N bet-2

a.

Aggressive pharmacothera

py

Dx. Of Severe Asthma is clinical

Summary

Magnes

ium

Sulfa

te

NPPV

if

suita

ble

Trach

eal

Intubation

GA

ECMOContinuous

Nebulization

SteroidsAtrovent Parenteral

Beta-2 agonist

Aminophyll.

SummaryTherapy Strength of

Recommendation

Quality of

EvidenceShort acting

Beta2 a.Strong High

Systemic steroids

Strong High

Magnesium sulf. Strong High

Anticholinergic Strong ModerateIV Salbutamol Strong Moderate

Aminophylline Strong Moderate

Key Points•Prevention is the best.•Early recognition of severity.

•Aggressive therapy• Very close observation.

•High threshold for intubation

Than

ks Th

ank

sThan

ks

Questions?

During the management of the patient in the PICU, he

developed acute renal failure.

What are the possible causes?