All posts by TheTraumaPro

What’s The INR Of Fresh Frozen Plasma?

So what’s the INR of FFP? Or stated another way, what’s the lowest you can correct a patient’s INR using infusions of fresh frozen plasma?

One of the mainstays of correcting coagulopathy, either from hemorrhage or due to medication like warfarin, is transfusion of FFP. Frequently, clinicians will write orders to administer FFP until a certain INR is achieved. What is a reaonable INR?

A “normal” INR is 1.0, plus or minus about 0.2, depending on your laboratory. However, two separate studies have shown that transfusion of FFP will not reliably decrease the INR below about 1.7. 

Bottom line: The answer to the question is about 1.6. If any clinician orders FFP transfusions with a goal INR below this, it probably won’t happen. And since transfusions of any product have risks, my “juice to squeeze” ratio of risk vs benefit begins to fail at an INR of 1.6. Below that point, the patient needs a normal temperature and good perfusion to drop their INR further.

References:

  • Toward rational fresh frozen plasma transfusion: the effect of plasma transfusion on coagulation test results. Am J Clin Pathol 126(1):133-139, 2006.
  • Effect of fresh frozen plasma transfusion on prothrombin time and bleeding in patients with mild coagulation abnormalities. Transfusion 46(8):1279-1285, 2006.

Best Of: CT Contrast Via Intraosseous Catheter

The standard of care in vascular access in trauma patients is the intravenous route. Unfortunately, not all patients have veins that can be quickly accessed by prehospital providers. Introduction of the intraosseous device (IO) has made vascular access in the field much more achievable. And it appears that most fluids and medications can be administered via this route. But what about iodinated contrast agents via IO for CT scanning?

Physicians at Henry Ford Hospital in Detroit published a case report on the use of this route for contrast administration. They treated a pedestrian struck by a car with a lack of IV access sites by IO insertion in the proximal humerus, which took about 30 seconds. They then intubated using rapid sequence induction, with drugs injected through the IO device. They performed full CT scanning using contrast injected through the site using a power injector. Images were excellent, and ultimately the patient received an internal jugular catheter using ultrasound. The IO line was then discontinued.

This paper suggests that the IO line can be used as access for injection of CT contrast if no IV sites are available. Although it is a single human case, a fair amount of studies have been done on animals (goats?). The animal studies show that power injection works adequately with excellent flow rates. 

The authors prefer using an IO placement site in the proximal humerus. This does seem to cause a bit more pain, and takes a little practice. A small xylocaine flush can be administered to reduce injection discomfort in awake patients. Additionally, the arm cannot be raised over the head for the torso portion of the scan. 

Bottom line: CT contrast can be injected into an intraosseous line (IO) with excellent imaging results. Insert the IO in a site that you are comfortable with. I do not recommend power injection at this time. Although the marrow cavity can support it, the connecting tubing may not. Have your radiologist hand-inject and time the scan accordingly.

Note: long term effects of iodinated contrast in the bone marrow are not known. For this reason, and because of smaller marrow cavities, this technique is not suitable for pediatric patients.

Related posts: 

Reference: Intraosseous injection of iodinated computed tomography contrast agent in an adult blunt trauma patient. Annals Emerg Med 57(4):382-386, 2011.

Orthopedic Hardware And TSA Metal Detectors

Many trauma patients require implantable hardware for treatment of their orthopedic injuries. One of the concerns they frequently raise is whether this will cause a problem at TSA airport screening checkpoints (Transportation Safety Administration)

The answer is probably “yes.” About half of implants will trigger the metal detectors, and these days that usually means a pat down search. And letters from the doctor don’t help. It turns out that overall, 38% are detected when the scanner is set to low sensitivity and 52% at high sensitivity. 

Here is a more detailed breakdown:

  • Lower extremity hardware is detected 10 times more often than upper extremity or spine implants
  • 90% of total knee and total hip replacements are detected
  • Upper extremity implants such as shoulder, wrist and radial head replacements are rarely detected
  • Plates, screws, IM nails, and wires usually escape detection
  • Cobalt-chromium and titanium implants trigger alarms more often than stainless steel

 If your patient knows that their implant triggers the detectors, they have two options: request a patdown search, or volunteer to go through the full body millimeter wave scanner. This device looks at everything from the skin outwards, and will not “see” the implant and is probably the preferred choice. If they choose to go through the metal detector and trigger it, they are required to have a patdown. Choosing to go through the body scanner after setting off the detector is no longer an allowed option. 

Reference: Detection of orthopaedic implants in vivo by enhanced-sensitivity, walk-through metal detectors. J Bone Joint Surg Am. 2007 Apr;89(4):742-6.

The Return On Investment Of A Career As An Intensivist

There is a shortage of intensivists in the US, particular in the field of surgical critical care. The are many possible reasons, from “graying” of the workforce and increased workloads to decreased reimbursement and increased legal risks. As usual, money is at the root of most problems in some form or another. So is being an intensivist actually “worth” it, and how do we figure something like that out?

A group at Chapel Hill attacked this question from a financial business/financial standpoint. They looked at the lifetime return on investment of choosing a critical care career compared to non-critical care practitioners in the same fields (surgery, medicine, pediatrics). They included income data, debt burden, opportunity costs and taxes in their analysis.

Using standard financial analysis techniques, the authors found that:

  • The financial value of the career choice of medical and pediatric intensivists was nearly identical to their non-critical care peers
  • The financial value of choosing a surgical critical care career was significantly less than that of a general surgeon
  • The lower value of a surgical critical care career was largely due to the opportunity costs of two years of lower salary during the fellowship
  • The relative value of an academic critical care career was always lower, and was most pronounced among internists

Bottom line: There are many factors that go into the choice of a career in critical care. They include job satisfaction, quality of life, and many other intangibles. But money frequently intrudes into the decision making process. It appears that choosing surgical critical care incurs some degree of financial penalty, and this may  be a factor that will exacerbate the shortage of these specialists.

Reference: The economic impact of intensivist fellowship training. Poster presentation at the EAST annual scientific session, January 2013.

The Three Strikes And You’re Out Airway Rule

Rapid airway control is key in critically injured trauma patients. But too many times, I’ve seen trauma professionals take far too much time to establish one. Here’s a good rule of thumb to use in these situations.

After pre-oxygenating the patient, your first pro gets a crack at it. They generally have the most time available, often 3-5 minutes before sats begin to drop.

In the unlikely situation that they are not successful, strike 1. Stop trying and resume bagging the patient. At this point, someone (trauma surgeon, lead medic) must get the crich set out. Then the next most experienced intubator gets a shot.

If they are not successful, strike 2. Resume bagging and open the crich set.

The most experienced intubator now gets their chance, using any advanced technology available. No success even now? Strike 3, use the crich set!

Bottom line: We should never allow more than 3 airway attempts, and sometimes clinical conditions will dictate fewer tries. Examples that come to mind are severe brain injury patients (hypoxia is bad) and patients who do not recover from oxygen desaturation when they are bagged. Don’t lose track of time and the number of attempts!