Asphyxiant gases
- Simple
asphyxiants :
Inert gases act by replacing oxygen in the air. Rapid death occurs when
oxygen falls below 10%.
Examples: methane, butane, nitrogen and helium.
Occupational exposures occurs while working in confined places
where these gases are liberated or used as in mines, storage refrigerators,
leakage of cooking gases.
Chemical asphyxiants: Gases which affect the
respiratory mechanism central or peripheral .
Examples
of these gases: Carbon
monoxide, hydrogen sulfide and hydrogen cyanide.
Occupational
Exposure: in Iron
and steal industry, cook industry, cement industry (carbon monoxide). Petroleum
industry (hydrogen sulphide). Hydrogen cyanide (electroplating of metals).
Mechanism
of action:
Hydrogen
sulfide . inhibition of the respiratory center.
Carbon
monoxide, combine with
hemoglobin giving carboxy-hemoglobin rendering it incapable to carry oxygen. it
has 210 times affinity to carbon monoxide than to oxygen.
Hydrogen
cyanide, inhibit
cytochrome oxidase that is responsible for extraction of the oxygen from the
blood by the tissue.
Clinical
picture due to exposure to asphyxiant gases:
·
Dyspnoea.
·
Blurring of vision.
·
Delirium, confusion and
hallucination.
·
Arrhythmia and anginal
pain.
·
Easy fatigability and
muscle aches.
Cyanosis
except in carbon monoxide the mucous membrane is red in color.
First
Aid of a worker suffering of gas asphyxia:
·
Carry him away from the
source of exposure to a well- ventilated place.
·
Release all the tight
clothes.
·
Prevent tongue
swallowing.
·
Extend the neck and the
worker may be in need of cardio-pulmonary resuscitation.
·
Oxygen supply.
Prevention:
follow general
rules
