What is Asthma? How can an Expert Witness help with a Medico-Legal Case?

May 3, 2022
by Hannah Farrell

Our Expert Witnesses in asthma are specialists in the management of this common and treatable condition.

Our Expert Witnesses in general practice have a profound knowledge of the management of chronic asthma and acute exacerbations.

With a strong understanding of appropriate standards of care and NICE Guidelines, in addition to a thorough knowledge of treatment pathways, our Expert Witnesses can advise on causation, breach of duty, current condition, and prognosis in Medico-Legal cases surrounding a diagnosis of asthma.

See below for a brief overview on general practice. Alternatively, contact an Expert Witness in asthma to see how they can help.

What is Asthma?

Asthma is reversible obstruction of the airways, resulting from an inflammatory response and hyper-responsiveness of the airways. Asthma involves bronchospasm (leading to narrowed airways) and excess mucosal secretions (leading to plugged airways). Asthma presents with shortness of breath, chest tightness, cough, and a wheeze.

How do our lungs work?

Our lungs are located in the chest cavity (thorax), lying either side of the heart, and are responsible for oxygenating blood; via pressure changes, the lungs draw air into the chest, where the air comes into contact with blood in the small blood vessels of the lung (pulmonary capillaries).

Each lung is divided into lobes; the right lung consists of the superior, middle, and inferior lobes, whereas the left lung has only the superior and inferior lobes.

On inspiration, the path of air is as follows:

  1. In through the mouth/nose
  2. Down the trachea
  3. Into the right/left main bronchus
  4. Into the lobar bronchi
  5. Into the bronchioles
  6. Into the alveoli, where oxygen is delivered into the blood and carbon dioxide and other waste products are passed from the blood into the lung.

What causes asthma?

Asthma can be triggered by a variety of stimuli, such as pollen, pollution, smoke, pet hair, exercise, air temperature, and stress.

An individual’s likelihood of having asthma is multifactorial; the aetiology of asthma is incompletely understood, however there are links with a history of atopy, a family history of asthma, smoking, obesity, and prematurity or low birth weight.

How is asthma treated?

Asthma has a clear stepwise treatment plan, which treats individual’s dependent on the severity of their symptoms.

The types of medications used include:

  • Short-acting beta2-agonist (SABA): causes smooth muscle in the airways to relax, reducing bronchospasm.
  • Inhaled corticosteroid (ICS): reduces inflammation in the airways.
  • Leukotriene receptor antagonist (LTRA): leads to bronchodilation and reduces inflammation.
  • Long-acting beta2-agonist (LABA): works the same as SABA, but the effects last longer.
  • Maintenance and reliever therapy (MART): a LABA and ICS in one inhaler.
  • Theophylline: relaxes smooth muscle in the airways, causing bronchodilation. It also causes dilation of pulmonary blood vessels and reduces the inflammatory response.
  • Long-acting muscarinic receptor antagonist: cause bronchodilation.
1Very mild, intermittentInhaled SABA as and when required e.g., salbutamol
2Exacerbation within last two years, using SABA 3+ times per week, symptoms occurring 3+ times per week, or asthma causing person to wake up.Addition of a regular ICS e.g., beclometasone.
3Symptoms persistingAddition of a LTRA e.g., montelukast.
4Symptoms persistingAddition of a LABA e.g., salmeterol.   Consider stopping the LTRA.
5Symptoms persistingCommence a MART regimen with low dose ICS e.g., formoterol inhaler combined with beclometasone (Fostair®)
6Symptoms persistingIncrease the dose of ICS either via  MART regimen or separate LABA, ICS, and SABA.
7Symptoms persistingIncrease dosage of ICS and LABA.   Consider addition of theophylline or long-acting muscarinic receptor antagonist.