Should I or shouldn’t I start an IV

Should I or shouldn’t I start an IV

Number 2 on the list of the most asked for classes is,  Do you teach how to start an IV? And I say  sure do, but WHY do you want to learn how to start one? (#1 is Do you teach suturing)

I get that deer in a head lights look for a few minutes, and invariably the answer is “So I can hydrate my patient”

That is actually a good answer, but like suturing there is a time and a place to do both and to NOT to do them. Like sewing up a wound you can do great things for an injured person……if done correctly. And you can do great harm to a person if done incorrectly or even correctly. Start an IV is much more than poking a hole in a vein and connecting some tubing to a bag of salt water.

This newsletter is not so much to teach you all how to start an IV  but to educate you all on the whys and why nots and hazards of starting a line on a patient. Oh and some training also!

So first what is a IV. IV is an abbreviation for IntraVenous It is not really accurate since anything inside a vein is IV. But it has stuck and we are stuck with it. An IV set is the collection of equipment used to access and deliver fluid in a sterile manner to a patient.

Here you see 2 types of IV catheters, The upper pink catheter is a “safety” catheter. The main parts are from left to right. The catheter itself. The stylet or needle the hub and the shield.

The lower catheter has no safety, and it is my preferred one. It’s parts from left to right are

The Catheter, The Stylet, and the Hub.

That is the parts that we gain access to the vein with.

The industry Standard is the Jelco ® brand catheter by Smiths Medical. IV Catheters are like shotguns. The BIGGER the number the smaller the size. Jelco ®  and most brands use a standard color chart for sizing the catheter

Green is 18 ga, Pink is 20 ga. Blue is 22 ga Yellow is 24 ga. Not pictured is the big bore catheters. 16 ga is grey and 14 ga is peach. For reference an 18 gauge catheter has an outer diameter of  1.3 mm, 16 gauge us 1.65 mm and 14 gauge is 2.11mm. 2mm is about the diameter of a 6 penny nail.

Image courtesy of Smiths Medical

Next is the delivery system

The major parts of the delivery system are Starting at the top is the spike, next is the drip chamber. Next  is the thumb wheel to control the flow, Spaced at random spots down the tube are medication and/or secondary access ports At the very end is the  hub. This is where we connect the tube to the catheter.

This tubing shown is standard 10 gtt. Or Drops per CC of fluid This means 10 drops into the drip chamber is equal to 1 cc of fluid given Stu tubing is your general workhorse everyday tubing set. It’s maximum flow is 1 liter in 10 minutes of so gravity feed,

The next type is High flow or blood tubing, This one we use for transfusing blood or for fluid resuscitation. Large amount of saline are infused at a very high rate. This type of tubing can infuse a liter in under one minute with pressure assist. The image below  shows a fully set up blood set.

This system with a power infuser can deliver 1 liter in under 60 seconds depending on the size of the catheter.

Those  are the main parts of an IV access and delivery set. Next up are the “Whens” When to start and when to stop an IV.

This is from The 2006 Institute of Medicine (IOM) Safe Practice

Established intravenous access should be medically justified. Generally accepted reasons include:

  • Volume infusion therapy, such as what might be needed in post resuscitation care or closed-container hypotension
  • Administering intravenous medications
  • Prehospital blood collection for testing such as verifying blood glucose results or rapid cardiac Troponin levels upon hospital arrival

And these are some of my reasons for starting a line

  • If your patient has lost or is losing a lot of blood
  • You need access to administer IV medications (IE Pain meds, Antibiotics etc.)
  • Your patient is dehydrated and is unable to rehydrate orally
  • Your patient was in a trauma event and is currently well but due to injuries may suddenly “Get worse” and you may not be able to start an IV.

Realistically you can justify a reason to start a line. But hold on there super medic! Are you QUALIFIED in your city or state to do so. Just because you know the HOW. If you do not have that slip of paper that says EMT-I or EMT-P, RN LPN, DO MD and you poke a hole in someone’s vein and give them some salt water you may be on your way to jail. If you look on every piece of equipment for an IV set it, all says Rx Needed or By physician order only.  In most of my classes, (except for certification classes) I always preface my class with :
This class is SHTF medicine. There is no help and none is expected. If you do NOTHING someone WILL die. However if you try to start an IV or set a compound fracture on 1st and Main in Anytown USA, you will more than likely go to jail for practicing medicine without a license.

Remember that. Let that sink in and YOU need to consider the implications of learning SHTF medicine.

OK back to the IV. We have a small list of when to start an IV. Now when should you NOT start an IV?
There is no absolute contraindication for IV cannula insertion, other than not being trained or qualified in the task. But there are some things to be aware of.

First if at all possible do not start an IV in an injury or burned or infected area. Next some medications if they leak can cause damage to the surrounding tissues. There are a few more but they are all on a case by case basis.

The clinical reason to NOT start an IV are pretty sparse.  You can 99% of the time justify the use as long as you’re a qualified person. Where IV’s become dangerous is when a person puts them in and is not really sure on the proper way. The most common post IV issue is infection. Most of the time it is local to the area and you get what we call a cellulitis. Once in awhile, you get a systemic infection in the blood stream that leads to what we call sepsis. This can be and is usually fatal. The next complication from IV use is whats called fluid overload.

Fluid overload or Hypervolemia is when there is too much fluid in the the body There are many different mechanism that will cause it but one is too much fluid from an unnecessary IV or poorly managed IV. There are calculations for administering the proper amount of fluid to a person. Children and people in heart failure are very easy to fluid overload, and without special drugs it is difficult to get it out quickly. Lasix is the most common prescription drug for getting rid of fluid, Dierese is the proper term. On the herbal side, Dandelion, Hawthorn and Horsetail do the job.  NOTE Giving a diuretic has it’s own hazards.

For the math whizzes here there are a couple of calculations for determining how much fluid you can give a person;

Calculated Using the “4-2-1” Rule for Children

  •      For 0-10kg: 4 mL/kg/hr
  •      For 10-20kg: + 2 mL/kg/hr
  •      For >20kg: + 1 mL/kg/hr

So in plain English you have a child that weighs 10kg  so 4mlx10kg =40ml hour MAX.

Notice the red PLUS + sign in the formula. That is ADDED to the original 10 kg of weight.

For a moderately healthy child this is the  amount of fluid that the child can handle without it collecting in the extremities  or worse in the lungs.

For adults this is one that works well:
100/50/20 rule

Maintenance IV fluids for a 24-hour period:

  •   100 mL/kg for the first 10 kg
  •   50 mL/kg for the next 10 kg
  •   20 mL/kg for every kg over 20 (divide by 24 for hourly rate)

So for  a 70kg man here is the formulas: Using 100/50/20:

  • 100 × 10 kg = 1000
  • 50 × 10 kg = 500
  • 20 × 50 kg = 1000
  • Total = 2500
  • Divided by 24 hours = 104 mL/hr maintenance rate

The math seems complicated but it must be mastered PRIOR to starting your first IV.
Now these formulas are for normally healthy people that are injured are have a need for the fluid. It is a totally new ballgame for someone with kidney disease, heart failure liver disease. ( I’ll let you all in one a little trade secret. I use the 421 method on adults also!)


There are 2 classes of IV fluids we give.

Crystalloids and Colloids.

A crystalloid is a fluid based on mineral salts or sugars. A partial list of each is here:

  • Normal or 0.9% Normal Saline
  • Lactated Ringers
  • Acetated Ringers
  • D5, D10 D50 and Water (Dextrose 5% 10% 50%)
  • Hartmanns Solution ( Very rare in the US)
  • Half Normal Saline 0.45%
  • My favorite for fluid resuscitation, Plasmalyte


Colloids are very different. It used to be thought they could replace blood and or plasma. And some do. In fact blood and plasma ARE colloids. Crystalloids are mineral based whereas colloids are starch or blood based. (Short version)

Examples of colloids

  • Albumin
  • Whole blood or Packed red cells
  • FFP Fresh Frozen Plasma
  • Hespan
  • Dextran

I hope this news letter helped to show that IV’s are VERY useful. And it is a LOT more than poking a hole in someone and hooking a tube up to it. A lot of careful thought needs to go into the starting of one.  Now that being said. IF I was out in the middle of no where New Mexico (And there is a lot of that!) And if a person I was with was hurt and I felt that they needed an IV I would not hesitate to start one. Why? You can always take it out if not needed. And if things take a turn for the worse It is a blessing to have it than to try to start one on a de-compensated patient.  I would just use what we call a Heparin or Saline lock. It is an IV catheter inserted into the vein, flushed well and capped. No unnecessary fluids being giving, no mobility restrictions, but instant IV access if needed.
IV’s are nothing to be afraid of. But they do command a lot of respect and some good training on the How, the When and the Don’t.

I am starting to get The Medic Shack classes back in swing. Politics notwithstanding people need to learn how to care for themselves and for their loved ones. I will have local schedule back up with in the next few weeks. Stay tuned for new updates.

As much as we need “Tactical” style medicine I want to shift my sights to fully embrace a sustainable style of SHTF medicine. Yes it is important to know how to stop severed arteries bleeding or restart a stopped heart. But it is just as important to know how to control high blood pressure or treat a UTI or cure a sinus infection. With that in mind I am redoing and adding some classes on basic family medicine. Now remember no matter how much SHTF training you get it is no substitute for your family practice doctor. But in this day and age SHTF is much more than zombies rogue governments or a CME. As I have said before losing your insurance or a job is a SHTF event. But with the proper training and putting back some supplies the majority of minor to moderate healthcare issues can be handled.

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