Category Archives: Resuscitation

The “Double-Barrel” IO: Can It Work?

Intraosseous lines (IO) make life easy. They are quicker to insert, have a higher success rate, and require less experience than a standard IV. And they can be used for pretty much any solution or drug that can be given through an IV.

But there are some limitations. They can’t be inserted into a fractured bone. The manufacturer cautions against multiple insertions into the same bone. A second insertion should not be performed in the same bone within 48 hours.

But, as with so many things in medicine, there is little in the way of proof for these assertions. They seem like good ideas for precautions, but that does not mean they are correct. No real research has been done in this area. Until now.

The concept of using two IO needles in one bone was explored in an animal model by researchers in Canada. They used a swine model (using the foreleg/humerus, to be exact), and tested several infusion setups.

Here are the factoids:

  • Infusing crystalloid using an infusion pump set to 999ml/hr took 30 minutes with a single IO, and 15 minutes with a “double-barrel” setup
  • Giving crystalloid using a pressure bag set at 300 mm/Hg took 24 minutes with a single IO, and 23 minutes with double the fun
  • The double-barrel setup also worked for a blood/drug combo. 250cc of blood and 1 gm of TXA in 100ml of saline infused via pump in 13 minutes.
  • Simultaneous anesthesia drugs (ketamine infusion in IO #1, fentanyl and rocuronium bolus in IO #2) without problems
  • Multiple fluid + drug infusion combinations were tested without incident
  • There were no needle dislodgements, soft tissue injuries, fractures, or macrohistologic damage to the bone or periosteum

Bottom line: Remember, these are pigs. In the ten years since this study, I’ve not seen any human research. So don’t do this in humans yet. However, this is pretty compelling evidence that the double-barrel IO concept will work in people. And it appears that infusion pumps must be used for effective, fast infusions. I recommend that prehospital agencies with inquiring minds set up a study in people to prove that this works in us, too.

Reference: Double-barrelled resuscitation: A feasibility and simulation study of dual-intraosseous needles into a single humerus. Injury. 2015 Nov;46(11):2239-42. doi: 10.1016/j.injury.2015.08.029. Epub 2015 Sep 11. PMID: 26372229.

Hypotensive Patient? You’ve Got 90 Seconds!

You’re running a trauma activation, and everything is going great! Primary survey – passed. Resuscitation – lines in, fluid going. You are well into the exam in the secondary survey.

Then it happens. The automated blood pressure cuff indicates a pressure reading of 72/44 mmHg. But the patient looks so good!

You recycle the cuff. A minute passes, and another low pressure is noted, 80/52. You move the cuff to the other arm. Xray comes in to take some pictures. You roll the patient. 76/50. Well, you say, they were lying on the cuff. Recycle it again.

A minute later, the pressure is 56/40, and the patient appears gray, is very confused, and is diaphoretic. It’s real! But how long has it been really? An easy five minutes have passed since the first bad reading.

Bottom line: Sometimes it’s just hard to believe that your patient is hypotensive. They look so good! But don’t be fooled. If you get a single hypotensive reading, STOP! You have 90 seconds to figure out if it’s real, so don’t do anything else but. Check the pulse rate and character with your fingers. Do a MANUAL blood pressure check. It’s fast and accurate. If you have the slightest doubt, ASSUME IT’S REAL.

This tip also applies when you get an error reading or the cuff does not detect a pressure. You can take a moment to check central and peripheral pulses, but you must still get a real reading on a blood pressure cuff within 90 seconds. If you can’t, the hypotension is the real deal and must be treated appropriately. And immediately.

Don’t get suckered into trying to figure out what’s wrong with the cuff despite how good your patient looks. Remember, your patient is bleeding to death until proven otherwise. And it’s your job to prove it. Fast!

How To Remember Those “Classes of Hemorrhage”

The Advanced Trauma Life Support course lists “classes of hemorrhage”, and various other sources list a similar classification for shock. I’ve not been able to pinpoint where these concepts came from, exactly. But I am sure of one thing: you will be tested on it at some point in your lifetime.

Here’s the table used by the ATLS course:

classes_of_shock

The question you will always be asked is:

What class of hemorrhage (or what % of blood volume loss) is the first to demonstrate systolic hypotension?

This is important because prehospital providers and those in the ED typically rely on systolic blood pressure to figure out if their patient is in trouble.

The answer is Class III, or 30-40%. But how do you remember the damn percentages?

multiscore-maxi1

It’s easy! The numbers are all tennis scores. Here’s how to remember them:

Class I up to 15% Love – 15
Class II 15-30% 15 – 30
Class III 30-40 30 – 40
Class IV >40% Game (almost) over!

Bottom line: Never miss that question again!

MTP And The Blood Availability Trap In Trauma Team Activations

Early availability of blood is a key component in the successful resuscitation of severely injured trauma patients. All trauma centers have implemented massive transfusion protocols (MTP) to ensure rapid delivery of blood products to the trauma bay.

Unfortunately, locating the blood bank in some remote corner of the basement is common practice, as far from the trauma bay as possible. This guarantees a delivery delay once the MTP is activated. To offset this, many centers have implemented policies to make a limited quantity of blood products available in the trauma bay.

This supply can be located in a blood refrigerator located nearby. Or it may be a practice of calling for emergency release blood if the trauma professionals believe it might be necessary. Some trauma centers have codified this so that highest-level activations automatically have a cooler of blood products delivered, hopefully before patient arrival.

However, I have observed while visiting numerous centers that this often causes an unintended consequence. It can actually slow MTP activation!

How can that be, you say? It’s simple. Critically injured patients result in an intense and highly charged trauma activation. The surgeon is concentrating on keeping the patient alive and orders the emergency release blood to be hung. The resuscitation continues. “Hang another unit.” And so on.

Eventually, the temporary supply runs out. Then everybody looks at each other and does a facepalm. Nobody thought to activate the MTP!

How can this be avoided? The key is to do everything possible to activate it from the very start. Here are some tips:

  • Use an objective scoring system to trigger MTP. The two most common ones are the ABC score and the Shock Index. Both are easy to calculate, and can frequently be used based on the prehospital report. This means the MTP can be activated before the patient even arrives.
  • If you open the blood refrigerator or touch the emergency release blood, activate the MTP. This will give you two to four units to buy time for the first MTP cooler to arrive.
  • Empower everyone in the trauma bay to speak up. Make sure everyone knows the rules listed above, and encourage them to speak up if they see that any of them are met. “Team leader, should we activate the MTP?”
  • Don’t be shy! If you only transfuse one unit of refrigerator blood and stop, no harm, no foul. The unopened MTP cooler can be sent back to the blood bank with no risk of waste.

Bottom line: Don’t get suckered into forgetting to activate the MTP just because it looks like you have blood available. Automate the process so you never run out again.

MTP Activation Criteria For Pediatric Patients

Early resuscitation, particularly with blood products in patients with hemorrhage, is literally a lifesaver.  As each minute ticks by, survival slowly diminishes. To facilitate this, massive transfusion protocols (MTP) have been designed to rapidly deliver sizable quantities of blood products to the trauma resuscitation bay.

One of the recurring issues I see at trauma centers is the lack of a reliable way of activating the MTP. Many centers publish what I consider “psychic criteria.” These promote criteria that involve the amount of blood loss over four or twenty-four hours. Who even knows?

Delays in activating the MTP frequently occur because no one thinks about it when a critically injured patient arrives. All of the trauma professionals are busy with the patient and are rudely surprised when they ask for the first unit of blood.

Objective MTP activation criteria have been developed and are well-supported by the literature. The ABC score and the shock index are two of the more common methods. Both are based on observations made upon patient arrival (and possibly before if a prehospital report is received).

The ABC score uses four criteria:

  • Heart rate > 120
  • Systolic blood pressure < 90
  • FAST positive
  • Penetrating mechanism

If any two of these are present, there is a 50% chance that massive transfusion is warranted.

The Shock Index (SI) uses the initial vital signs to perform a quick and dirty calculation by dividing the heart rate by the systolic blood pressure.  A score greater than or equal to one predicts at least a 2x higher need for blood. Of the two, SI is more easily calculated and gives a marginally more accurate result.

But what about children? The ABC score was evaluated in pediatric patients and was found to be much less sensitive than in adults. Combining the ABC score with an age-adjusted Shock Index improved the accuracy only slightly. This was named the ABC-S score.

Several adult and pediatric trauma centers in the Denver area collaborated to test a new score using the ABC-S score in combination with serum lactate and base deficit. This was termed the ABC-D score. Clever.

Here are the factoids:

  • A retrospective review of patients aged 1-18 from a single trauma registry who had received a blood transfusion during their initial care
  • The study included 211 children, of whom 66 required massive transfusion
  • The three methods listed above were compared, and the ABC-D score was found to be the most predictive of MTP
  • ABC-D was 77% sensitive and 79% specific
  • The authors showed that the accuracy and balance between sensitivity and specificity improved for each point increase in the ABC-D score.
  • They concluded that ABC-D may be a useful tool to expedite the delivery of blood products during a trauma resuscitation.

Bottom line: Hmm. The system that they developed and the analysis of their experience appears to be sound. But unfortunately, it fails the practicality test. Here’s the sticking point. How long does it take to obtain that initial blood specimen, send it to your lab, and then return stat results to your trauma bay? Once you receive the results, you then activate the MTP and wait another 5-10 minutes for the first cooler to arrive!

That’s an awful long time to wait for blood while you watch a child hemorrhaging in front of you. So what to do? For now, use one of the existing systems to make a rapid decision. And always err on the side of activation. You can always send the blood back if you don’t need it!

Reference:  The ABC-D score improves the sensitivity in predicting need for massive transfusion in pediatric trauma patients. J Pediatr Surg. 2020 Feb;55(2):331-334. doi: 10.1016/j.jpedsurg.2019.10.008. Epub 2019 Nov 1. PMID: 31718872.