“I need a doctor in Trauma 1 right now!”
You run into the resuscitation room, and before you is a swarm of ED staff surrounding what appears to be a minimally responsive infant. Your staff is so well-trained that one of them has already appropriately positioned the airway while your respiratory therapist entered the room immediately behind you and has begun to prepare for the possibility of a “definitive airway intervention.” An initial pulse oximeter reading is 98% on room air. For the moment, you are going to trust that both “airwaand breathing” are being satisfactorily addressed.
Although two attempts at peripheral intravenous access were unsuccessful, your nurses were able to harvest a sufficient amount of blood to perform a rapid bedside glucose test. It is 22 mg/dl. You have finally been able to squeeze through the mass of humanity to assess your patient and notice that she is diaphoretic and pale. The nurses tell you she was carried to the resuscitation room directly from triage in response to her depressed activity and appearance. It seems as if “C” (Circulation) and “D” (Disability) are now your foremost priorities. Your patient appears to be less than one year of age, consistent with the information obtained from the Broselow-Luten tape—the measurement also performed by your nurses.
Your first spoken words, “I need an…” are interrupted by one of your staff handing you an intraosseous (IO) needle. Because you are “old-school,” they know you feel more comfortable with the manual IO device as opposed to the newer and more popular version that is inserted using a drill. Being right handed, you are most accustomed to pediatric IO insertion in the right proximal tibia.
Trying your best to be patient, you utilize a drilling motion against the flat portion of the bones lightly caudad and medial to the tibial tuberosity. You feel the characteristic “give,” and the needle stands secure in the upright position. You remove the stylet, attach your syringe, and aspirate, but nothing returns. Hmmm…Could there be a bone plug obstructing flow?
You speak a second time. “I need the ultrasound machine.” Taking your linear ultrasound probe, you place it adjacent to the needle-entry site and activate the Color Doppler function. As you gently push the contents of a 10-cc syringe into the IO (Figure 1, below), you notice the following image on your ultrasound screen (Figure 2).
FIGURE 1:FIGURES 2 & 3:
Figure 3 demonstrates obvious subcortical “blush,” confirming the presence of the intraosseous needle tip within the marrow cavity. You are, indeed, “in.” However, you also note something a little different. You see a thin vertical line of color starting in the marrow cavity and traveling retrograde toward the IO needle entry site. You repeat a small push and once again notice the same vertical color ascending within the bony canal.
What does this mean? It means your IO needle is not a tight fit in the bony canal created between the entry site and marrow cavity. Although other characteristics of a successful IO placement are noted-such as an upright, stable needle and a flushable line, you are at risk of extravasation. The nurses, who have been ahead of you from the onset, don’t notice this very subtle finding but are reassured by the very obvious subcortical color burst. It is obvious they expect you to quickly “push” the usual 2 cc/kg of 10% glucose to rectify the clinically-obvious hypoglycemia.
You then use your words for the third time since you’ve entered the room. “We’re in, but fluid is refluxing through the needle tract; I need the infant IO drill.” You prepare the contralateral left proximal tibia, insert the IO, aspirate a small amount of characteristic “tomato-juice” appearing bone marrow, gently push 2 cc/kg of 10% dextrose, and observe a brisk subcortical burst of color without highlighting of the needle tract (Figures 4 and 5). This is what you want. You proceed to attach IV pressure tubing using the commercial kit designed for this purpose. You continue with an infusion of intravenous glucose. A repeat bedside glucose level drawn a few minutes later is 218 mg/dl, and your patient is now happy, active, smiling, and playful.
It turns out that your patient had acquired a mild seasonal gastroenteritis at her daycare center. Her mother had been advised to provide small and frequent sips of a commercially available rehydration fluid. Unfortunately, she purchased a rehydration sports drink that had zero calories; translation: “no glucose.” Infants simply do not have adequate glycogen stores to “fast” for extended periods of time. The patient’s clinical outcome, fortunately, was very good, while the parents and staff learned some extremely valuable lessons.
In particular, this case caused the physician involved to consider the benefit of IO access via drill as opposed to his customary manual insertion. One of Vince Lombardi’s famous quotes was “Fatigue makes cowards of us all.” The emergency physician’s corollary is “Haste takes twenty points from my IQ.” In this case, the emergency physician came perilously close to pushing fluid through an intraosseous line whose fit within the cortical bone was not sufficiently tight to prevent reflux of infusing fluid, risking extravasation into the soft tissue. It seems intuitive that IO access via drill would make for a “cleaner, tighter” tract and reduce the risk of extravasation. A comparison of manual and drill insertion techniques assessing the relative frequency of extravasation would likely provide useful information.