Tag Archives: EMS

General

Using Mechanism of Injury In Your Trauma Activation Criteria

Leave a comment

The Centers for Disease Control and Prevention (CDC) published a set of Guidelines for Field Triage two years ago. Click here to download them. They list 4 tiers of activation criteria to help prehospital providers triage patients appropriately to trauma centers. 

Tier 1, which are physiologic criteria, and Tier 2 (anatomic criteria) are very accurate in predicting injury serious enough to require trauma team activation. Tier 3 contains mechanism criteria, and many centers who use these verbatim in their activation criteria end up with a fair amount of overtriage. Some centers even see a significant number of patients who meet Tier 3 criteria go home from the ED!

The Yale department of Emergency Medicine looked at intrusion into vehicle criteria (more than 12" near an occupant, more than 18" anywhere on the vehicle) to see if they are a valid predictor for admission or trauma center transport. It was a retrospective review of EMS transports to the Yale ED or to one satellite site. 

Unfortunately, the number of vehicles that met intrusion criteria (48) was small compared to the number without significant intrusion (560). This makes the data a little less convincing than it may have been. The likelihood that intrusion would require trauma center admission (Positive Predictive Value) was only 26%. The likelihood that trauma center resources would be utilized (for issues like death, ICU stay, operation, spinal injury or intracranial hemorrhage) was only 13%. The authors recommend that the CDC guidelines be tweaked based on this data.

Bottom line: I think the numbers are far too small to convince the CDC to change their guidelines. But I would urge each trauma center that uses the intrusion criteria for activation to carefully study how many of those patients have minor injuries or go home from the emergency department. They may find that they can rely on other more accurate criteria and decrease their overtriage rate at the same time.

Reference: Motor vehicle intrusion alone does not predict trauma center admission or use of trauma center resources. Prehospital Emerg Care 15:203-207, 2011.

General

Violating Resuscitation Guidelines for Prehospital Traumatic Arrest

Leave a comment

Eight years ago, the National Association of Emergency Medical Services Physicians (NAEMSP) and the American College of Surgeons Committee on Trauma (ACS-COT) released guidelines regarding withholding or terminating resuscitation in traumatic cardiopulmonary arrest (TCPA). Survival rates were extremely low (<2%) and were thought to have poor outcomes. But validation of the guidelines has been challenging, and some even doubted that EMS personnel could accurately assess these patients in the field!!

Researchers at Mt. Sinai Hospital in Chicago performed a large retrospective study of all patients in TCPA brought to their hospital by the Chicago Fire Department over at 7.5 year period. These patients met exclusion criteria but had been resuscitated anyway. Their series was relatively large (294 patients), and looked not only at the ultimate outcome, but also at EMS performance and cost.

They found that field assessments by EMS were very accurate and consistent. Violation of the guidelines resulted in only 6 survivors, and they all were resuscitated to a neurologically devastated state (4 brain dead, 1 family withdrew support, 1 sent to TCU with long-term GCS 6). No loss of neurologically intact survivors would have occurred if the guidelines were followed. Finally, the cost of trying to resuscitate these patients was $385,000 per year.

Bottom line: EMS can and should apply the NAEMSP/ACS-COT criteria for traumatic cardiopulmonary arrest and withhold resuscitation for these patients. Tragically, it is an expensive waste of time to try to bring them back. 

To review the NAEMSP guidelines, click here.

Reference: The consequences of violating current guidelines regarding resuscitation of patients in prehospital traumatic arrest. Presented at the 34th annual Residents Trauma Paper Competition at the 89th Annual Meeting of the ACS Committee on Trauma, March 10, 2011.

General

The EMS Second IV In Trauma

Leave a comment

One of the critical maneuvers that EMS providers perform is establishing initial vascular access. This IV is important for administering medications and for initiating volume resuscitation in trauma patients. Prehospital Trauma Life Support guidelines state that every trauma patient should receive two large bore IV lines. But is this really necessary?

The upside of having two IVs in the field is that the EMS provider can give lots of volume. However, a growing body of literature tells us that pushing systolic blood pressure up to “normal” levels in people (or animals) with an uncontrolled source of bleeding can increase mortality and hasten coagulopathy.

The downside of placing two lines is that it is challenging in a moving rig, sterility is difficult to maintain, and the chance of a needlestick exposure is doubled. So is it worth it?

A group at UMDNJ New Brunswick did a retrospective review of 320 trauma patients they received over a one year period who had IV lines established in the field. They found that, as expected, patients with two IVs received more fluid (average 348ml) before arriving at the hospital. There was no increase in systolic blood pressure, but there was a significant increase in diastolic pressure with two lines. The reason for this odd finding is not clear. There was no difference in the ultimate ISS calculated, or in mortality or readmission.

Bottom line: This study is limited by its design. However, it implies that the second field IV is not very useful. The amount of extra fluid infused was relatively small, not nearly enough to trigger additional bleeding or coagulopathy. So if another IV does not deliver significant additional fluid and could be harmful even if it did, it’s probably not useful. Prehospital standards organizations should critically look at this old dogma to see if it should be modified.

Reference:

  • Study of placing a second intravenous line in trauma. Prehospital Emerg Care 15:208-213, 2011.
General
Gallery Leave a comment

Need CPR? There’s An App For That!

The San Ramon Valley Fire Protection District has released an iPhone app that gives users a window into their 911 dispatch center. When you install the app, you can indicate that you are trained in CPR. Your phone then provides your GPS location, and you can be notified of any sudden cardiac arrest events in your area. You can then proceed to the incident and render assistance, if appropriate.

App users can view all active incidents and the status of dispatched units. If an ambulance passes you or you are stuck in a traffic jam, just tap the screen to find out the details. They can also be notified of incidents by type, and monitor live emergency radio traffic. 

The only downside is that leaving GPS location apps active in the background can significantly shorten your battery life. I think we can expect more communities to begin offering services like this in the near future.

General
Gallery Leave a comment

Dry Seal Chest Tube Suction Systems

The original chest tube collection system traditionally consisted of three chambers. The picture above shows the classic three bottle system (which I actually remember using during residency). On the left is the suction control bottle that determines how much suction is applied to the patient. The middle bottle provides one way flow of air out of the patient, the so-called water seal bottle. Finally, the right bottle collects any fluid from the pleural space.

Collection systems used in hospitals are much more tidy than this, wrapping all three into one modular unit. However, if you look closely you can identify parts of the system that correspond to each of the bottles.

The problem with the older systems is that they typically require water in the “water-seal” chamber to maintain one-way flow out of the patient. If this chamber is compromised by knocking the system over (see this post), air may be able to enter the patient’s chest, giving them a big pneumothorax.

Management of chest tube collection systems by EMS is tough. It’s very easy to tip the system during air or ground ambulance runs, putting the patient at risk. Some manufacturers have developed so called “dry-seal” systems that use a mechanical one-way valve to avoid this problem.

I have not been able to use one of these systems yet. Here is my take on the pros and cons:

  • Pro – immune to tip-over and malfunction of the water-seal chamber
  • Con – more difficult to detect an air leak. Current models require either injection of a small quantity of water, tipping the system, or converting to a water-seal system.
  • Con – no literature regarding safety of this relatively new technology

Bottom line: Looks like a great idea to me, especially for EMS use. Once they get to the hospital, the unit can be changed to a water-seal system or a larger dry-seal system with the water injection port inthe dry-seal chamber.