Enzymatically Augmented Subcutaneous Infusion (EASI) In Out-Of-Hospital Care

Background Challenges to IV access outside the hospital The out-of-hospital setting can pose myriad challenges to the provider attempting to gain access to the intravascular compartment. In an individual patient encounter, placement of an intravenous (IV) catheter may be hampered by anatomy (e.g. venous collapse in hypotension), positioning (e.g. entrapment), and environmental conditions such as lighting and vehicular motion. These problems may be compounded in situations where multiple patients simultaneously require expedited IV access. Therefore, both "host" (i.e. patient) and "environment" (i.e. physical setting) parameters can contribute to a mismatch between desire for, and ability to achieve, access to the intravascular compartment.

The aforementioned issues with IV line placement all make the assumption of presence of an operator with appropriate Advanced Life Support (ALS)-level training and credentials. Such may not be the case in a mass casualty incident (MCI) situation, or in a situation where initial responders are Basic Life Support (BLS) level. Thus, consideration of potential barriers to intravascular compartment access should include "personnel" as well as "host" and "environment" parameters.

Case for importance of access to intravascular compartment Is intravascular access really important? Assuming that an EMS system could fiat easy and widespread access to the intravascular compartment in an MCI or more routine ALS or BLS response, is there impact on outcome? Unfortunately, as is often the case with EMS interventions, there is little or no randomized controlled evidence addressing the issue - in fact, related literature on penetrating trauma suggests that prehospital fluid resuscitation may be deleterious. However, clinical practice as well as standard emergency medicine and trauma resuscitation teaching (such as the Advanced Cardiac Life Support course and the Advanced Trauma Life Support text) do emphasize importance of early fluid resuscitation for a variety of injuries and illnesses.1 In addition, literature addressing MCI situations (e.g. crush injuries) makes a strong case for the importance of fluid replacement.2 Besides opening an avenue for fluid replacement, catheter-based access to the intravascular compartment allows for reliable delivery of medications. For patients who are not tolerating po intake, or for those who otherwise stand to benefit from parenteral drug delivery, catheter-based access to the intravascular compartment allows for administration of repeated doses of a variety of drugs while avoiding multiple (often painful) injections. Once the catheter is placed (currently, in a vein), the access line is available to both initial and subsequent caregivers.

It is obvious that out-of-hospital caregivers may use the access line for administration of drugs in the (limited) prehospital pharmacopoeia, but it is equally true that pre-establishment of intravascular access saves a step on arrival to the next level of care. Practitioners in today's EDs currently benefit, in savings of nursing time, from not having to take time to establish IV access in patients transported to the hospital by ALS units. This helps both the individual patient with pre-established IV access, since ED staff can immediately administer time-critical drugs - including those not in the ALS armamentarium - and also aids the resource-taxed ED whose staff can execute duties other than starting IV lines. Furthermore, though there is no concrete supporting evidence, common wisdom holds that placement of a (smaller) IV line and fluid administration through that line, may facilitate subsequent placement of a larger IV line due to more fluid in the vascular compartment.

Thus, the balance of evidence from a variety of standpoints (outcomes research, accepted practice and teaching, logistics) supports an argument that ability to gain access to the intravascular compartment is an important priority for out-of-hospital care. Importantly, it should be noted that for "ED" one could substitute "triage tent" or other MCI-related care site since intravascular compartment access is of obvious import in MCI/disaster-type situations.