Coagulation Screen

Measure when the patient [6]:

Has hepatic disease
Is on warfarin or anticoagulants
Has eclampsia or pre-eclampsia (particularly if platelet count <100 or dropping acutely)
Has a history of inappropriate excessive bleeding following previous surgery or post trauma
Has a family history of bleeding disorders
Has severe sepsis (ongoing hypotension or organ dysfunction despite adequate fluid resuscitation)
Has major haemorrhage (requiring more than 4 units of blood acutely)

Bedside whole clotting time

Available in the Downloads section of the Resources page:

Blood transfusion and the Anaesthetist Blood Component therapy 2005, Association of Anaesthetists of Great Britain and Ireland

Specific coagulation tests will depend on your lab facilities

Bedside whole blood clotting time

Take 2 ml of venous blood into a small, dry, clean, plain glass test tube (approximately 10 mm x 75 mm)
Hold the tube in a closed fist to keep it at body temperature (around 37°C)
After 4 minutes, tip the tube slowly to see if a clot is forming. Then tip it again every minute until the blood clots and the tube can be turned upside down
Failure of a clot to form after 7 minutes, or a soft clot that breaks down easily, suggests coagulopathy

Bedside whole clotting test is not very reliable and may give false results. Laboratory help must be sought whenever available and clinical acumen should dictate the diagnosis in the absence of lab help.