Below is an excerpt from a lessons learned compilation titled “First to Cut: Trauma Lessons Learned in the Combat Zone.” Though it is geared toward FST surgeons and forward medical providers, some of the lessons are applicable to tactical medics and mountain rescue. The larger take-away point is that the physiology occurring distally to a tourniquet applied for a long duration needs to be considered when changing or loosening, especially in environments where medical care may be limited (e.g., Third World).

“Four Hours of Tourniquet Time”

“26 y.o. male with foot traumatic amputation and
multiple frag wounds to the right leg with a high thigh
field tourniquet in place. Arrived to the CSH with SBP of
100 HR of 120. we had no report on duration of the
tourniquet. We took down the tourniquet and he promptly
coded. We put the tourniquet back up, intubated him and
gave him fluid and bicarb and he came back. We found
out later that the tourniquet had been in place for over 4
hours….”

The use of tourniquets – while rare in civilian trauma is
very common in combat injuries. Tourniquets are the
number 1 instrument that a medic can employ to lower the
KIA numbers. The use of tourniquet with application until
the absence of a distal pulse by default causes distal
ischemia. Release of a functioning tourniquet after several
hours can result in the release of acidic fluid and potassium.
The patient intubated and without a head injury can be
briefly hyperventilated. Before taking down a long
duration tourniquet make sure the patient is well hydrated,
resuscitated, adding an ampule of sodium bicarbonate or
THAM can prophylax against the release of “bad humors”,
lactic acid, and potassium. Also release the tourniquet
slowly – if the rare arrhythmia arises re–employ the
tourniquet and retry after further bicarb and fluid. If the leg
is necrotic remember “life before limb” and perform an
amputation.

Lessons Learned:
–Prolonged tourniquet times can result in the release
of acidotic fluid and hyperkalemia
–Perform 4 compartment fasciotomy with all lower
extremities with significant tourniquet times