52 - Primary Assessment Circulation

KYJ 52 C = Circulation
Part 3 of 5 part series on Primary Survey.
Circulation

Third step in the Primary survey is assessing circulation.

Being the third letter of the alphabet, think of three parts to this assessment.
1. Output - pulse
2. Skin indicators - colour/warmth
3. Bleeding

First is output. You want to know if the patient has a heart beat. Check carotid and radial pulse simultaneously. The carotid pulse confirms that the patient has a cardiac output with enough pressure to perfuse brain. The radial pulse confirms that you have enough output to perfuse kidneys.
Given a normal BP of 120/80 , a patient with a Systolic pressure (SBP) of above 80mmHg is able to perfuse their kidneys. They will still have s palpable radial pulse. But should their state of shock be so advanced that SBP is less than 80, then their radial pulse can't be palpated.- severe shock.
If their SBP drops below 70 the femoral and brachial pulses can't be felt.
Carotid pulse is impalpable with an SBP below 60mmHg. At this pressure, cerebral perfusion is feeble, and the patient is technically dead.  BLS, and ALS and correcting the causes (Hs &Ts) is required if the patient has any chance of surviving.
Palpate the carotid and radial  together.  Feel tone, and gauge the rate.  Fast and strong indicates early shock, whilst a rapid weak and thready pulse is late shock.

Next is skin indicators. Is the patient demonstrating pink mucous membranes, or are they showing pallor, ashen grey, of cyanosis?  Remember pink is good and blue is bad!
Feel the skin- is it cool or warm? Is it dry or clammy/moist?
The classic moderate to severe shock patient demonstrates skin which is typically, pale, cold and clammy as a result to vascular perfusion being redistributed from skin to the core or central vital organs. No blood flow = pale cold and clammy!

Finally, blood loss. Is the patient bleeding?  If there is uncontrolled external bleeding, then this needs immediate direct pressure and elevation.

After assessing the state of the patient's circulation, the international standard is to establish vascular access.
Formerly this required 2 large bore IV  cannulas (catheters) either 24 or 16 gauge. However recently there has been a greater focus on establishment of an intraosseous catheter for severe shock and trauma, where there has been three attempts at intravenous access or a time lapse greater than 90seconds.
Many IO devices are on the market, all with limitations. A devise that is quick, reliable and secure should be favoured.
A tibial devise is of limited use with abdominal or lower limb trauma.
A humerus device is limited with upper limb or shoulder injuries,
A manubrial (sternum) device can not be used on children under 12. Despite limitations, they are easier, and quicker than traditional IV establishment, especially in shocked patients.

What IV fluid should be hung. Well that is up to your protocol, and is the proverbial "holy grail" of answers, but most trauma research is suggesting 0.9% normal saline (NaCl).
Caution with large fluid loads should be exercised, as hyperchloraemic acidosis can occur, as can fluid overload, hypothermia, and dilutional coagulopathy.
Remember most patients are already coagulopathic and have dilutional anaemia on arrival; don't make it worse.