FLUID RESUSCITATION
IN THE ER
LMH ER Rounds
September 22, 2015
Prepared by Shane Barclay
OBJECTIVES
Review flow rates through different IV
Review types of access for fluids – IV and IO
Review types of IV solution
In the simulation, we will be concentrating on practicing using
the new IV sets and using the EZ-IO drill and the
FASTresponder Intraosseous device.
FLOW RATES THROUGH
DIFFERENT IV CANNULA
Flow rate is related to the diameter and the length of the
cannula as well as the pressure exerted.
As we all remember !: Flow is inversely proportional to the
4th power of the radius [Pouseuille's law] - i.e. small changes
in cannula diameter = large changes in flow.
Therefore a large IV that is long, may actually have a slower
rate than a smaller but shorter caliber IV cannula.
GENERAL RULES OF THUMB
A large bore cannula is preferable to a narrow bore cannula.
A shorter cannula is preferable to a longer cannula.
A larger proximal vein is preferable to smaller distal vein.
Upper limbs are preferable to lower limbs, especially in.
cardiac arrest.
FLOW RATES WITH DIFFERENT
IV CATHETERS
20 G 25mm
18 G 32 mm
16 G 32mm
Gravity
Flow Rate
ml/min
65
104
220
Time in
minutes to
Infuse 1 liter
15
9.6
4.5
Time in minutes to
Infuse 1 liter with
pressure bag
9.5
6.5
2.8
14G 32mm
Syringe push
IV pump
302
250
16
3.3
4
63
2.0
CHOICE OF VASCULAR ACCESS
• A peripheral cannula of size 18G or greater is preferable to
infusion by central line for rapid fluid delivery. Remember a
central line is ‘longer’.
• For any critically ill patient, hand IVs should be avoided. Try to
obtain antecubital fossa veins.
• If after 2 IV attempts no success, tell the team leader and he/she
should consider an intraosseous access.
INTRAOSSEOUS ACCESS
Flow rates of 60–100 ml/min of crystalloid, via a 15 gauge tibial
intraosseous needle, have been achieved in the adult using the
hydraulic pressure of a large syringe.
In a resuscitation setting, IO access is preferable to CVP
insertion if peripheral vascular access cannot be obtained rapidly
— higher success rates on first attempt (85% versus 60%)
— shorter procedure times (2.0 versus 8.0 min)
TYPES OF INTRAOSSEOUS DEVICES
FastResponder
Sternal IO
EZ-IO Drill
TYPES OF INTRAOSSEOUS DEVICES
• Videos demonstrating both the FASTResponder Sternal
intraosseous and the EZ IO drill device can be viewed as
separate videos on the LMHER web page.
SELECTION OF IV FLUID
There are:
Crystalloids (Normal saline, Ringer’s) and
Colloids (Pentaspan, Hextend..)
Randomized clinical trials comparing crystalloids versus
colloids have found NO advantage of one over the other.
Colloids however are much more expensive.
MAKEUP OF DIFFERENT
IV SOLUTIONS
Na
Cl
K
Ca
Lactate
Calories
pH
D5W
D5/NS 154
154
-
-
-
170
170
4
~5
N/S
154
154
-
-
-
-
~5
2/3-1/3 270
R/L
130
51
109
4
2.7
-
9
~6
~6.5
28 *
* Na lactate, not Hydrogen lactate
RINGER’S LACTATE
Was introduced in 1930s when sodium was added as a buffer to aid
treatment of metabolic acidosis (which occurs in severe hemorrhage and
trauma)
It is also closer to ‘normal pH’ then normal saline so is often preferred in
large volume resuscitation.
However calcium can bind some medications as well as the citrated
anticoagulant in blood, so is not the ideal for transfusion patients.
It is also slightly more isotonic than normal saline and therefore should
not be used where plasma osmolality is important – ie acute brain injury.
NORMAL SALINE
1 liter of N/S will distribute ~ 250 ml into the vascular
compartment (thus the 3:1 rule of resuscitation 3 parts IV
solution for every 1 part blood loss)
However the 3:1 rule is often not accurate and may be as
much as 7:1 or even 10:1.
This is due to decreased colloid oncotic pressure, capillary
leak and crystalloid replacement that can occur in major
hemorrhage.
NORMAL SALINE
Normal saline supplies supra-physiologic sodium and
chloride which is useful for retaining intravascular volume
and in patients with metabolic alkalosis (ie vomiting,
diarrhea, GI obstruction).
But in large volumes, N/S can induce hyperchloremic
metabolic acidosis.
SO.. RINGERS OR NORMAL SALINE ?
Ideally, the source of hypovolemia, electrolyte
abnormalities and the actual volume replacement
required should aid in fluid selection.
However, IV fluid selection is not as important as the
amount of IV fluids given to an appropriate therapeutic
end point.
Bottom line: neither Ringer’s nor Normal Saline have
shown superiority in clinical trials.
THIS MAY ALL BE IRRELEVANT IN
TRAUMA PATIENTS
So all the previous being said, the old ATLS guidelines used to
recommend 2 liters of IV fluid followed by BP assessment and then if
needed more IV fluids.
The latest ATLS guidelines now say that in trauma, give 1 liter of IV fluid,
and if no normalization of BP, give blood products.
This negates a lot of the issues of what to give for IV fluids in trauma!
WHEN DO PATIENTS NEED
FLUID THERAPY?
All critically ill patients, all trauma patients and any
patient suspected of being hypovolemic needs IV therapy.
The challenge is how much and of what.
The topic of ‘shock’ will be dealt with in a separate
rounds.
The topic of fluid assessment will also be dealt with in a
separate rounds topic.