Assessment and treatment of the acutely ill adult
C for Circulation 1/2
If the patient is speaking to you they must have a carotid pulse. Feel for the radial and if it is thready or absent that gives qualitative information on the state of the circulation. Blood pressure measured non-invasively by oscillotonometry might be inaccurate. Consider performing a manual BP with a sphygmomanometer. The need for invasive blood pressure monitoring (reliable, real time, accurate) should precipitate early Intensive Care transfer.
Secure or ensure vascular access. Any working cannula is worthwhile. If you are giving drugs or slow IV fluids an 18 gauge cannula is fine. If you need to rapidly infuse fluid or blood larger cannulae are needed.
If the patient is shut down this may be difficult to achieve. This is another reason for early Intensive Care referral. Insert any size of cannula and call for help. An 8 F line inserted in the femoral vein can be achieved quickly by a skilled operator and is excellent for rapid volume resuscitation in many cases. Insertion of a central venous cannula at this stage is not usually a priority; get good big peripheral access and an arterial line in first.