Final answer:
Unfractionated heparin is given for rapid anticoagulation in acute medical conditions such as deep vein thrombosis, pulmonary embolism, unstable angina, myocardial infarction, cardiac surgery, and during dialysis.
Step-by-step explanation:
Unfractionated heparin (UFH) is typically administered in a medical setting when there is a need for rapid anticoagulation. This can occur in situations such as the treatment of acute venous thromboembolism (including deep vein thrombosis and pulmonary embolism), in the management of unstable angina and myocardial infarction, as part of cardiac surgery procedures, and during dialysis to prevent clotting. UFH works quickly, has a short half-life, and its effects can be reversed if necessary, making it useful in acute care settings where immediate effect and flexibility in drug duration are desired.