Article Bites #26: Time for a new location or Technique in infants? Success rates of proximal tibia IO placement in pediatric patients as determined by post-mortem CT

Article: Harcke, H. T., Curtin, R. N., Harty, M. P., Gould, S. W., Vershvovsky, J., Collins, G. L., & Murphy, S. (2020). Tibial Intraosseous Insertion in Pediatric Emergency Care: A Review Based upon Postmortem Computed Tomography. Prehospital Emergency Care, 1-7.

 Background:  The most commonly used (and recommended) site for intraosseous (IO) access in pediatric patients is the proximal tibia. The primary objective of this study was to determine the accuracy of emergency IO placement in pediatric patients by both prehospital providers and emergency department providers.

Methods: The authors determined accuracy of tibial IO placement using post-mortem CT.  They reviewed 92 cases referred by the state medical examiner for post-mortem CT and found 31 where a tibial IO had been placed. Successful IO placement was defined by needle placement between the proximal 5% to 30% of the tibia with the needle tip in the medullary cavity.  Needle length was determined by measuring via CT or appearance of the needle hub color.

 Key Results: Among 31 cases, there were 42 total tibial IO insertions.  The authors found that:

·      Infants < 6 months of age accounted for 30/42 IO placements.  Overall success in this age group was 47%.  There was variability in success by IO needle size (56% for 15 mm needle and 0% success for 25 mm needle).

·      Success rate amongst patients 6 months to 2 years of age was 83% (n=6)

·      Success rate among patients > 2 years of age was 100% (n=6)

·      The most common reason for failure varied by needle size.  For 15 mm needle it was that the needle was outside the bone (45%, n=11) or embedded in the cortex  (45%, n=11), while for the 25 mm it was perforation of the tibia (83%, n=6).

·      Rates of failure were not significantly different between EMS and ED personnel (30% failure rate for ED personnel, 46% failure rate for EMS).

Conclusions: While there is some risk of bias as this study only examined non-survivors, the failure rate of proximal tibial IO placement in pediatric patients, in particular those < 6 months of age, was alarming.  Size mattered: 15 mm needles were much more likely to be successful that 25 mm needle (which was unsuccessful in 6/7 patients under 2 years of age).  These results are in line with a prior cadaver study by Maxien et. al. demonstrating a high rate of malposition (64%) of IO in infants < 1 year.

These findings raise the question of whether how can we improve success rates: manual insertion over drill? Mandatory needle sizes? Increased training? Alternative site such as the distal femur?

 What this means for EMS: Pediatric IO placement has a high failure rate, especially in infants < 6 months of age.  At minimum, to improve success rate a 15 mm needle should be chosen in this age group.   Further research is needed to address whether alternative sites or methods may be preferable.

Article Summary by Maia Dorsett, MD PhD FAEMS FACEP, @maiadorsett

Interested in a more in depth discussion of this article and pediatric IO? - see the PEC podcast Deep Dive Episode.

Discussion Forum: A pressor in a push…

Consider Three Clinical scenarios:

Scenario A:

EMS responds to the scene of a cardiac arrest.  Patient is found in PEA and ROSC is achieved after 5 cycles of CPR.  Immediately Post-ROSC and 3 minutes since the last dose of epinephrine, blood pressure is 110/80, HR 125, EtCO2 45 mmHg, SpO2 of 95%.  Post-ROSC EKG shows an inferior MI.  As the patient is being packaged for transport, a repeat blood pressure of 70/30 is obtained, HR is now 90, and EtCO2 has declined to 30 mmHg.  The paramedic considers starting an epinephrine or norepinephrine drip, but thinks that utilization of push dose pressors may suffice and make it easier to rapidly extricate patient and begin transport towards the local STEMI receiving center… 

Scenario B:

EMS responds to an assisted living facility for altered mental status in a 78 year-old male.  The patient has been becoming progressively more altered over the course of the day and the nursing home reports a fever.  The patient is obtunded and responds only to painful stimuli.  An indwelling Foley catheter is noted to be draining cloudy urine.  VS obtained show a BP 68/30, HR 110, SpO2 89% on room air, RR 24, EtCO2 22 mmHg.  IV access x 2 is obtained on scene, and fluids and oxygen administration are initiated.  The paramedic considers whether push dose pressors may be indicated for this patient… 

Scenario C:

EMS responds to a motor vehicle collision.  The patient has suffered major blunt trauma to the head and pelvis.  Assisted ventilations are initiated, the patient is placed in spinal motion restriction, and a pelvic binder is applied.  Transport is initiated to the nearest trauma center which is 15 minutes away.  VS are BP 80/60, HR 120, RR 12 (assisted), SpO2 96%, EtCO2 30 mmHg.  IV access is initiated and the paramedic considers push dose pressors to support the blood pressure in anticipation of need for airway management en route or in the ED…

Push dose pressor use has become increasingly common in emergency departments and has been introduced to several EMS systems, however the evidence regarding the benefits and/or harms of their use outside of the operating room remains limited.  

We are interested in what your current EMS system is doing and why?  Are you using push dose vasopressors?  If not, why not?  If so, what are the indications and dosing/frequency?  What is the protocol for their use and what safeguards against medication error are in place?  Are you tracking any quality measures for their use?

Please share your comments below by NOVEMBER 20th to be included in the subsequent summary post.