LIFE-THREATENING PROBLEMS - Medicine for Mountaineering and Other Wilderness Activities - page 23

be duplicated. Simply reading about this technique is not adequate. Therefore, no instruc-
tion about the technique of CPR is provided in this topic.
If an automated external defibrillator (AED) is available, shocks as indicated by the
AED can be provided.
Atthesametimetheairwayisbeingopened,rescuersshouldquicklyexaminetherestof
theperson,lookingparticularlyforexternalbleeding.Anymajorsourceofbleedingshould
becontrolledimmediately,bydirectpressureifpossible.Ifbleedingfromanextremitycan-
not be controlled by direct pressure, a tourniquet should be used ( Chapter 12: Soft-Tissue
Injuries ) .
If the airway is open and the individual still is not breathing but a pulse is present, the
rescuer must perform rescue breathing until the person starts breathing again or resuscit-
ation efforts are terminated. Lightning strikes can disrupt breathing and heart activity, but
the heart usually restarts promptly. Breathing, on the other hand, may not restart for many
minutes—evenhours.Ifrescuebreathingisnotperformed,theheartandbrainaredeprived
ofoxygen,andeventuallytheheartbeginstofibrillateandstops.Ifeffectiverescuebreath-
ing is done, the respiratory centers in the brain eventually start working again and the per-
son resumes breathing. Full recovery usually follows as long as breathing has been ad-
equately supported. Therefore, if possible, rescue breathing should not be stopped as long
as effective heart action is present ( Chapter 29: Lightning Injuries ).
Starting and Stopping Resuscitation
If cardiac arrest is the result of trauma, CPR in a wilderness situation is futile. If a trau-
matized individual has no pulse, CPR should not be started.
Other reasons for not starting resuscitation include signs that the person has been dead
for some time or has injuries not compatible with life, such as a massive brain injury or
other mutilating injuries. The earliest sign that an individual is dead and cannot be resus-
citated is dependent lividity, a red or purple color that results from settling of blood that is
not circulating in the dependent portions of the body. This discoloration typically covers
the back if the person is lying face up (supine) but is not present over the shoulders, but-
tocks,orotherpressurepointswherepressurefromthebodykeepsthebloodfromentering
the tissues. The discoloration is in other areas if the person is lying face down (prone) or
ononeside.Rigormortis(stiffeningofthemuscles)developswellafterdependentlividity.
Decomposition is a very late change. The major exception to this rule is that a severely hy-
pothermic person can have dependent lividity and may be stiff but can occasionally still be
resuscitated under ideal circumstances.
Innontraumaticcardiacarrest,themostcommoncauseisaheartrhythmdisturbance.In
general, if CPR can be started in less than four minutes and a shock administered to restart
the heart within ten minutes, the person has a chance of survival with good neurologic out-
come. If the individual does not respond to CPR after fifteen minutes (when an AED is not