The Bhopal Gas tragedy from almost three decades ago, is the raw memory of poisonous gas, for a generation of us. We may be have moved on in time from the order of that tragedy, but a host of every other situation – accidents at home, industrial settings, work places and even heavy vehicular traffic, can put us at risk of inhaling harmful gases. The case is more so in the case of structural fires where both the victims and rescue workers – including fire-fighters are at risk.
By definition, an emergency presenting as harmful gas inhalation is a case where a person has breathed in harmful gases and the vapours, & particulate matter contained in them. Toxic as the case is, it is difficult to diagnose & the treatment is complicated. In clinical manifestation, the ill-effects of harmful gas inhalation are more severe in children aged below 11 and adults aged over 70.
Instances of Poisonous Gas Inhalation
- Poisonous gas inhalation typically occurs in victims and fire-fighters caught in structural fires.
- Cigarette smoking also causes similar damage on a smaller scale over a longer period of time.
- People who are trapped in fires may suffer from poisonous gas inhalation independent of receiving skin burns. The incidence of poisonous gas inhalation however increases with the percentage of total body surface area burned. Patients may not show symptoms until 24-48 hours after the event.
Harmful Effects of Poisonous Gas Inhalation
The harmful materials given off by combustion injure the airways and lungs in three ways: heat damage, tissue irritation and oxygen starvation of tissues (asphyxiation).
Signs of Heat Damage
- Singed nasal hairs
- Burns around and inside the nose and mouth
- Internal swelling of the throat
Tissue irritation of the throat and lungs may appear as:
- Noisy breathing
- Black or gray spittle
- Fluid in the lungs
Asphyxiation is apparent from:
- Shortness of breath
- Blue-gray or cherry-red skin colour
- In some cases, the patient may not be conscious or breathing.
In addition to looking for the signs of heat damage, tissue irritation, and asphyxiation, the physician will assess the patient’s breathing by the respiratory rate (number of breaths per minute) and motion of the chest as the lungs inflate and deflate. The patient’s circulation is also evaluated through pulse rate (number of heart beats per minute) and blood pressure. Blood tests will indicate the amount of dip in oxygen level and by-products of poisonous gases. Chest X-rays are too insensitive to show damage to delicate respiratory tissues, but can show fluid in the lungs (pulmonary oedema).
Properly placed and working poisonous gas detectors in combination with rapid evacuation plans will minimize a person’s exposure to poisonous gases in the event of a fire. When escaping a burning building, a person should move close to the floor where there is cooler, clear air to breathe because hot air rises, carrying gases and particulate matter upward. Finally, fire-fighters should wear proper protective gear.
First Aid for Poisonous Gas Inhalation
- The primary focus of treatment in case of poisonous gas inhalation is to maintain an open airway and provide adequate level of oxygen.
- If the airway is open and stable, the patient may be given high-flow humidified 100 per cent oxygen by mask.
- If swelling of the airway tissues is closing off the airway, the patient may require the insertion of an advanced airway (which can be put only by medical experts) to artificially maintain an open airway.
- Oxygen is often the only medication necessary. However, patients who have cough with wheezing, indicating that the airways are narrowed or blocked, will require further treatment.
- There are also antidotes for specific poisonous gases in the blood; dosage is dependent upon the level indicated by blood tests.
- In institutions where antidotes are available, ‘hyperbaric oxygen therapy’ may be used to treat poisonous gas inhalation resulting in severe carbon monoxide or cyanide poisoning. This treatment requires a special chamber in which the patient receives pure oxygen at three times the normal atmospheric pressure, thus receiving more oxygen faster to overcome all complications.
Although the outcome depends on the severity of the poisonous gas inhalation and the severity of any accompanying burns or other injuries, with prompt medical treatment, the prognosis for recovery is good. However, some patients may experience chronic lung problems following poisonous gas inhalation, and those with asthma or other chronic respiratory conditions prior to poisonous gas inhalation may find their original conditions have been aggravated by the inhalation and injury.
The ill-effects of harmful gas inhalation are more severe in children aged below 11 and adults aged over 70.