|It is vital to think first and foremost of your
own safety as a rescuer because if you hurry and disregard safety
precautions then you may injure yourself. At which point you
become another victim in the case instead of a rescuer. The
major dangers are fire, wire, gas, glass and blood.
Fire related injuries can cause:
- Thermal burns
- Chemical injury
Thermal burn usually occurs at the skin or airway, the latter
being the more serious referred to as thermal mucosal burn
or edematous inhalation injury. When the extremely hot air
is inspired, an inflammatory reaction happens around the airway.
This swelling or constriction of the airway makes it difficult
or sometimes impossible to breath. Thus the victim may show
signs of dyspnea, stridor and hypoxia. Other clues may be
a cough, a changed voice, burnt face, stinged eyebrows and
nose hairs, carbon deposits around the mouth, carbonaceous
Chemical injury referred to as gas inhalation injury is also
very serious. The severity depends on what toxin is inspired
(dependant on what is burning) and the concentration in the
bloodstream. There are 35000 known toxins including CO, SO2,
HCN, CO2, HS, etc. CO is the most common. It is a systemic
toxin produced by the incomplete combustion of carbon containing
substances. It is dangerous because it's affinity for hemoglobin
(Hb) on red blood cells is 250 times greater than that of
oxygen. If inspired, the oxygen saturation curve shifts to
the left (Bohr effect) thus leading to hypoxic injury. The
heart and brain are especially vulnerable. At 20% CO-Hb victims
may present with headache, nausea, vomiting, dyspnea, dizziness.
At 20-40% CO-Hb they show visual disturbances, irritability,
poor judgment. At 40-60% CO-Hb they show confusion, seizure,
coma, ataxia, syncope. At levels greater than 60% victims
usually cannot survive because the cardiovascular and respiratory
systems collapse and they go into shock.
What to do as a rescuer if faced with fire at the scene?
Call 911 and wait for the firefighters to clear the danger.
Do not attempt to do so by yourself.
Highly charged wires are extremely hot and can cause very
dangerous fires (this should always be kept in mind). Coming
in contact with a wire can lead to:
- Thermal burns
- Electrical deregulation in the body
There are 5 critical factors that determine the severity
of the electrical injury:
- Tissue resistance (proportional to the dryness of the
- Current intensity (how many amps? often only the voltage
is known, so you can approximate from that)
- AC (120V/240V found in house outlets) vs. DC (12V found
in batteries and cars)
- Duration of contact
- Current path
Current travels in the path of least resistance. In the body,
the most resistant organ is the skin and the least are the
vessels. Therefore the path of least resistance is usually:
skin - bones - muscles - nerves - vessels. The current path
can be determined by looking for an entrance wound (looks
like a bullet wound) and an exit wound. This can be helpful
because it gives the rescuer a good idea as to what organs
might be affected. If the heart is affected the victim may
show an arrhythmia, ventricular fibrillation or asystole.
If the brain is affect then the respiratory centers in the
medulla are deregulated leading to respiratory failure. If
the muscles are affected then there may be tetanic contractions.
What to do as a rescuer? Wait for a Hydro Quebec worker or
other qualified person to remove the wire.
Noxious levels of gas are very difficult to detect and sometimes
overlooked. They can be the result of:
- A gas leak
- Combustion (look for signs of fire)
Scenes were gas may be a serious danger include cars in closed
environments, trains derailed, volatile metals burning, tires
burning, insecticides burning. Insecticides are especially
alarming because they release organophosphates that lead to
a cholinergic syndrome characterized by salivation, lacrimation,
urination, defecation and gastric emesis (S.L.U.D.G.E.).
Gases are classified into the following categories:
- Asphyxiants: target the lungs
CO, HCN, hydrocarbons (methane, propane, common in barbeques)
- Systemic toxins: prevent oxygen transport or use by cells
CO, HCN, CS2
- Simple irritants: cause inflammation
NH3/4 (also know as ammonia), Cl
- Combined irritant and systemic toxin: H2S (smells like
rotten eggs, similar to HCN), metallic oxides
CO and HCN are two important gases. CO's effect was discussed
in the section about fire. HCN has a distinct smell like bitter
almonds and is usually found around pest control products,
photography equipment or metal polishing. Affected people
present with dryness, air hunger, dyspnea, confusion, seizure,
cardiovascular collapse, shock. The mechanism of action being
that the CN binds Fe3 (ferric state) thereby inhibiting cytochrome
oxidase and ultimately inhibiting oxidative phosphorylation.
With glass, you can cut yourself and
- Lose blood
- Get an infection
Try to carefully clear the glass around the victim with a
towel or other object before approaching.
If there is blood on or around the victim, first think to
put on gloves before approaching. The actual risk of disease
transmission during mouth-to-mouth ventilations is small with
only 15 cases reported in scientific journals in the past
40 years. Of the 15 cases, there were no cases of HIV, hepatitis
B/C or cytomegalovirus - arguably the most life threatening
diseases. Still, according to one survey, only 5% of people
would be willing to perform mouth-to-mouth ventilations on
a stranger indicating that there is a prevalent fear of disease
transmission. If the rescuer feels uncomfortable about performing
mouth to mouth, then there are options.
Compression only CPR is one such option which has been proven
to be a very effective alternative (see the physiology section
in the CPR step for details). Also, rescuers can and should
use facemasks whenever possible to prevent direct contact
and fluid exchange. If you think that you may have been exposed
to suspect blood, you can always visit the emergency department
(the faster the better) and they'll check you out and take
the appropriate course of action.
how well do you
know your stuff?