Asthma

IM - FM - THRA

Definitions

• leukotrines agents: inflammatory mediators of asthma, produced by leucocyte/ mast cells. they cause bronhoconstriction.

• Antileukotrine agents: These are drugs which function as leukotrine receptor antagonist e.g. montelukast OR leukotrine enzyme inhibitor - 5 lipooxygenase inhibitor like zileuton

Asthma

• Bronchial Asthma is reversible obstructive lung disease
• chronic air way inflammation and increased air way hyper-responsiveness

Typical symptoms of bronchial asthma include

• Wheeze

• Cough
• Chest tightness
• Dyspnea
• Air flow obstruction that is variable over short periods of time or is reversible with treatment

Introduction

• Approach to Patients with Shortness of Breath

• Asthma Epidemiology & Etiology

• Asthma Investigations & Criteria

Asthma Diagnosis, Management

• Diagnosis of Asthma & Severity

• Asthma Managements treatment Guidelines

• Inhaler technique

• Peak Flow Meter

Types of Asthma Presentations

• Acute Severe Asthma

CASE HISTORY - An asthmatic patient with dyspnoea and wheeze

A 25 year old male with long standing asthma is admitted with 2 days history of dyspnoea and wheeze. He has been unable to sleep because of cough and wheeze and his inhalers have run out. On examination, he appears dyspnoeic at rest, his respiratory rate is 28/min and oxygen saturation on air is 90%. There is reduced but equal expansion of chest with audible wheeze. There is no evidence of Pneumothorax clinically or on X-ray chest. Patient is given a nebulizer and put on 60% oxygen.

Arterial blood gases show

• pH 7.53
• PaO2 11kPa
• PaCO2 3.5kPa
• HCO3 20mmol/L
• SaO2 96%

Questions:

1. Which of the following does the patient have?
   • a. Acute respiratory acidosis
   • b. Acute respiratory alkalosis
   • c. Acute metabolicacidosis
   • d. Acute metabolicalkalosis

• b. Acute respiratory alkalosis
• pH is above 7.45 (alkalosis) and PaCO2 is low

2. Which of the following is true?
   • a. Patient is hypoxemic
   • b. Patient requires intubation
   • c. Oxygen should be reduced as pH is abnormal
   • d. Patient should be given steroids

• d. Patient should be given steroids.
• Steroids will treat underlying Bronchospasm

3. Patient did not improve and appears more drowsy and no wheeze is audible. Repeat blood gas pH 7.22, PaO2 10.5kPa, PaCO2 10.1kPa, HCO3 26mmol/L, SaO2 90%. Which of the following may the patient has developed?
   • a. Acute respiratory acidosis
   • b. Acute respiratory alkalosis
   • c. Acute metabolicacidosis
   • d. Acute metabolicalkalosis

• a. Acute respiratory acidosis
• Because muscle pump has exhausted due to increased work of breathing. Patient requires intubation and mechanical ventilation

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FM AT