When one is pressed for time in a situation with either an ongoing threat or multiple casualties, it is often not possible to completely expose a casualty and find all wounds from multiple shots or shrapnel. After identifying massive bleeding from a limb, it is better to initially place the tourniquet “high and tight” ensuring that there bleeding has been stopped before moving on to the next casualty. Don’t hesitate by questioning yourself if it’s needed or not. If there is active streaming or pulsating blood, place a tourniquet. Often its hard to tell venous from arterial in the dark or with a pant leg or sleeve diverting the flow.
A properly trained person can later convert the hasty tourniquet to a pressure dressing as soon as possible but within 4 hours or, if unable due to continued bleeding, place a tourniquet 2″-3″ above the wound to save as much tissue as possible.
Dr. John Kragh is the researcher we turn to with any tourniquet questions. He has many articles written if you search pubmed. He is currently involved in a couple more studies on the topic.
Here is an email from Dr. Frank Butler, of the CoTCCC, we posted on prolongedfieldcare.org with some of our tourniquet questions: https://prolongedfieldcare.files.wordpress.com/2014/11/removing-tq-comments-from-tccc-experts-jan-14.docx
The Tactical Emergency Casualty Care Comittee recently released this recommendation for civilians dubbed “First Care Providers:” https://dl.orangedox.com/P4vdx9cIm60c4pj0jJ
Our guidelines are based on those of the Comittee on Combat Casualty Care CoTCCC at www.cotccc.com.
My Prolonged Field Care Working Group echoes the recommendations with this article in the Journal of Special Operations Medicine: https://prolongedfieldcare.files.wordpress.com/2015/09/drew-jsom-fall-2015-edition-2.pdf
This is my Google Drive folder with tourniquet related resources: https://drive.google.com/folderview?id=0B7OAVQuGtbzATll4WG9uZ3BWTWs
I hope this gets you started in the right direction.