Out-of-hospital Airway Management in the United States

The below abstract is from Resuscitation, Volume 82, available at Science Direct. It provides a detailed examination of out-of-hospital airway management, success rates, and complicating factors. The crux of the article for tactical medics is the need to maintain skills through training, because the low ratio of calls to the need for invasive airway interventions, even in the EMS sector, suggests that real-world practice is not sufficient. It points to the low success rate of reported advanced interventions as proof, claiming that the rate might be high due to one not wanting to report failures. Finally, in addition to skill fade, failure is also attributed to vomit, blood, and mucus, all hindrances faced in the tactical environment, as a factors leading to failed advanced airway management. In the end, tactical medics may not manage enough advanced airways to maintain their skills, thus they need to find appropriate training models if live-tissue training is not available. Unfortunately, this article does not provide many alternatives.

A b s t r a c t
Objective: Prior studies describe airway management by single EMS agencies, regions or states.We sought
to characterize out-of-hospital airway management interventions, outcomes and complications across
the United States.

Methods: Using the 2008 National Emergency Medical Services Information System (NEMSIS) Public-Release Data Set containing data from 16 states, we identified patients receiving advanced airway management, including endotracheal intubation (ETI), alternate airways (Combitube, Laryngeal Mask Airway (LMA), King LT, Esophageal-Obturator Airway (EOA)), and cricothyroidotomy (needle and open). We examined airway management success and complications in the full cohort and in key subsets (cardiacarrest, non-arrest medical, non-arrest injury, children <10 and 10–19 years, rapid-sequence intubation (RSI), population setting and US census region). We analyzed the data using descriptive statistics.

Results:Among4,383,768EMSactivations, there were 10,356 ETI, 2246 alternate airways, and 88 cricothyroidotomies.
ETI success rates were: overall 6482/8418 (77.0%; 95% CI: 76.1–77.9%), cardiac arrest 3494/4482 (78.0%), non-arrest medical 616/846 (72.8%), non-arrest injury 417/505 (82.6%), children<10 years 295/397 (74.3%), children 10–19 years 228/289 (78.9%), adult 5829/7552 (77.2%), and rapidsequence
intubation 289/355 (81.4%). ETI success was success was lowest in the South US census region. Alternate airway success was 1564/1794 (87.2%). Major complications included: bleeding 84 (7.0 per 1000 interventions), vomiting 80 (6.7 per 1000) and esophageal intubation 12 (1.0 per 1000).

Conclusions: In this study characterizing out-of-hospital airway management across the United States, we observed low out-of-hospital ETI success rates. These data may guide national efforts to improve the quality of out-of-hospital airway management.

Rethinking Tension Pneumothorax

Rethinking Tension Pneumothorax

An interesting article in the Emergency Medicine Journal, “Tension Pneumothorax–Time for a Re-think?,” questions the traditional signs and symptoms of tension pneumothorax (TPT). The authors independently compiled and analyzed previous research dating from 1966 to 2003 determine if “classic” signs of TPT exist, and, if so, the rate of diagnosis. Essentially, the survey found that the majority of TPT cases do not present with classical signs, which necessitates a rethinking of how TPT recognition is taught (see Box 1). The authors also address the poor outcomes associated with needle decompression.

The article established that one must divide patients into two groups: 1) spontaneous breathing; 2) ventilated. This is important due to the ability of spontaneously breathing patients to compensate, thereby presenting differently. Group one displayed the ability to compensate during respiration with tension building (for a more detailed list of compensatory mechanisms, see Box 2). Up until time of death, cardiac output was reserved due to progressive tachycardia, incomplete transmission of positive IPP to the mediastinum (see Box 3 for group 1 signs and symptoms). Group two, however, presented differently due to not being able to compensate (see Box 4 and Table 1). Familiarity with the unique presentation of group 2 is obviously important because your patient may need to be ventilated en-route to a higher echelon of care.

The most intriguing findings were the poor correlation of TPT to mediastinal shift and tracheal deviation, two classic signs. The former is an inconsistent finding, except in children, due to mobility of their mediastinum. Moreover, tracheal displacement is also a poor indicator of mediastinal shift. In fact, in the this study, “it was absent in all 108 cases of suspected TPTs treated by paramedics with needle decompression and present in only 1 percent of those receiving needle decompression by flight nurses…. Even when present, the odds of experienced physicians diagnosing it are 50:50—that is, the same as tossing a coin.” Essentially, tracheal deviation is not diagnostic of TPT.

The authors also question the use of needle decompression as a diagnostic tool, due to associated morbidity (Box 8). For instance, “of 106 patients treated with tube thoracostomy by pre-hospital flight nurses, 38% had been attributable to failure of clinical improvement with needle decompression.” Furthermore, the authors are concerned with the use of needle decompression as a “rule-out” procedure, for no studies exist showing it as a sensitive test. Despite this, it is a therapeutic treatment and reduces time on scene when compared to chest tubes, which is important in the tactical environment. However, their research shows it is often used when no TPT is present, but that is an easier assessment after the fact. It should be highlighted that flutter valves, which are popular in the pre-hospital environment may cause re-tension according to their findings, so be vigilant in construction and re-assessment.

Overall, this is a detailed article that deserves consideration. It is worth your time to download the full version and prudently reassess your training and adjust accordingly.

References and tables from:
S Leigh-Smith and T Harris, “Tension Pneumothorax–Time for a Re-think?.” Emerg Med J 2005 22: 8-16.

Box 1
Box 2
Box 3
Box 4
Box 8
Table 1

Standard Gauze versus Hemostaic Agents: A New Look

A recent article published by the Academic Emergency Medicine journal found that when compared to standard gauze, hemostatic agents showed no improvement in hemorrhage control and prevention of re-bleeding. The findings indicated that the training is the the most important aspect of hemorrhage control. Obviously, hemostatics have their place, but they are not magic fairy-dust to be sprinkled on wounds, hoping for the best outcome. Moreover, it is clear that the basics saves lives, as the gauze and hemostatics were under direct pressure for five minutes. Finally, the study reveals the difficulties in accessing certain wounds–cavity versus puncture–with gauze and other delivery methods that ought to be considered.

(It should be noted that this study was funded by the US distributor of Celox, Sam Medical, but conducted by an agency within the Department of the Navy.)

Full Study
Littlejohn Hemostatic Comparison AEM 2011

Abstract

Objectives: Uncontrolled hemorrhage remains one of the leading causes of trauma deaths and one of
the most challenging problems facing emergency medical professionals. Several hemostatic agents have
emerged as effective adjuncts in controlling extremity hemorrhage. However, a review of the current literature
indicates that none of these agents have proven superior under all conditions and in all wound
types. This study compared several hemostatic agents in a lethal penetrating groin wound model where
the bleeding site could not be visualized.

Methods: A complex groin injury with a small penetrating wound, followed by transection of the
femoral vessels and 45 seconds of uncontrolled hemorrhage, was created in 80 swine. The animals
were then randomized to five treatment groups (16 animals each). Group 1 was Celox-A (CA),
group 2 was combat gauze (CG), group 3 was Chitoflex (CF), group 4 was WoundStat (WS),
and group 5 was standard gauze (SG) dressing. Each agent was applied with 5 minutes of manual
pressure. Hetastarch (500 mL) was infused over 30 minutes. Hemodynamic parameters were recorded
over 180 minutes. Primary endpoints were attainment of initial hemostasis and incidence of
re-bleeding.

Results: Overall, no difference was found among the agents with respect to initial hemostasis, rebleeding,
and survival. Localizing effects among the granular agents, with and without delivery mechanisms,
revealed that WS performed more poorly in initial hemostasis and survival when compared to
CA.

LEOs and First-Aid Kits Save Lives

We received this article today noting the benefit of first-aid kits for law enforcement officers: saving lives. Because they are often the first on the scene, their being properly trained and equipped is essential.

LINK

Pima County Sheriff’s Department __ Individual First Aid Kits (IFAK) PDF

Review of Tactical Medical Articles

Here is a link to reviews of tactical medical literature. None are current, but if one is interested in peer-reviewed articles, these are a good start.

Review of the Tactical Medical Literature

By: Tripp Winslow, MD MPH

In the medical literature, there is a paucity of peer-reviewed articles regarding Tactical Emergency Medical Services (TEMS). The majority of TEMS based articles are reviews of extrapolated EMS, Trauma, or Emergency Medicine literature. While these review articles are informative and promote awareness of TEMS as a specialty, it is evident that a greater effort must be made to advance the science and evidence based literature available for use in the field. In this journal scan identifying existing TEMS literature, I have summarized a few review articles and presented several original research papers as well. This review was carried out on PubMed. The bibliographies of all articles were reviewed for additional relevant articles.

LINK

Managment of Suspected Spinal Injury In TCCC

A large discrepancy between civilian and military medicine exists with respect to the importance placed upon spinal injury management. In the past, most combat injuries have been secondary to penetrating trauma. Therefore, during the initial phases of treatment, moving the casualty to cover would be the only concern, without taking the time to immobilize c-spine as a civilian medic would. However, new injury patterns are emerging. As Dr. Keith Gates noted in the Spring 2010 issue of The Journal of Special Operations Medicine (JSOM), blunt trauma is emerging more often as an mechanism of injury secondary to the increase in number of IED attacks. According unpublished data, 39% of casualties had mechanism of injuries secondary to blunt trauma. Additionally, according to JSOM, between June and December 2009, of the 119 casualties with blunt force trauma spinal fractures, 14 had spinal cord injuries. Thus, an increasing number of casualties are presenting with thoracic and cervical injuries on the modern battlefield.

This trend has not gone unnoticed. A working group was commissioned to address this issue, out of which a new technique for spinal protection emerged, called Spinal Motion Restriction (SMR). Essentially, the rescuer would use the casualty’s IBA to protect the thoracic spine, while taking care to not unnecessarily manipulating the c-spine during movement. The suggested changes to the TCCC protocol are as follows:

Care Under Fire:
3. Direct casualty to move to cover and apply self-aid if able. If casualty requires assistance, move him to cover. If mechanism of injury included blunt trauma (such as riding in a vehicle which was struck by and Improvised Explosive Device), minimize spinal movement while extracting him from the vehicle and moving him to cover. The casualty should be moved along his long spinal axis if at all possible while attempting to stabilize the head and neck.

Tactical Field Care and TACEVAC Care Insert new #2:
Use Spinal Motion Restriction techniques as defined below for casualties whose mechanism of injury included blunt trauma IF: a) they are unconscious; b) they are conscious and have mid-line cervical spine tenderness or mid-line back pain; or c) they are conscious but demonstrate neurological injury such as inability to move their arms and/or legs, sensory deficits, or parenthesis. For these casualties, leave the IBA in place and secure to protect the thoracic spine. The cervical spine may be protected by using a cervical stabilization device in conjunction with the casualty’s IBA or by an additional first responder holding the casualty’s head to maintain alignment with the back. Long or short spine boards should be used in addition to these measures when available (JSOM, Spring 10, pg. 60).

Unfortunately, initial findings from a pilot study conducted at USAISR found that if one keeps the IBA in place, in a supine position, without the helmet, the c-spine is put in extension. More problems surfaced during later discussions: 1) pouches commonly worn on the IBA could further injuries in the supine position; 2) IBAs obstruct evaluation and treatment, thus they are often removed; 3) SMR may not be protective.

In the end, more research needs to be done in light of the recent trends in wounds. As more soldiers and LEO officers are exposed to blunt trauma, medics need to be conscious of the potentiality injuries secondary to it. While Spinal Motion Restriction is unsatisfactory, it continues the conversation regarding treatment.

What are your thoughts and experiences?

Rhabdomyolysis in the Tactical Enviroment

Rhabdomyolysis (Rhabdo for short) secondary to a combination over exertion and dehydration is gaining attention in exercise circles due to documented cases recently with the increasingly popular high-intensity workout regimens. The threat of Rhabdo is not only confined to the the gym. It ought to be planned for and considered in the tactical environment as well. It is not a concern in the Care Under Fire stage of care, but, as Schwartz, et. al. note in Tactical Emergency Medicine, it ought to be addressed during tactical en route care. In addition to being caused by exertion and dehydration, Rhabdo and the subsequent renal failure my be secondary to a crush injury in the tactical environment. However, this brief essay assumes that crush injuries will tip-off care providers to included Rhabdo in their differential diagnosis. Rhabdo due to exertion may not, however, be as apparent.

Essentially, Rhabdomyolysis is the release of myoglobin into the blood stream, which damages the kidneys in two ways: 1) physically blocking the nerphrons with myoglobin; 2) chemotoxic toxification. While this can only be definitively determined by a lab test at a higher echelon of care, it is beneficial to keep this in mind. For instance, in a disaster situation or MCI, an operator may exert himself and present with acute muscle pain and local edema. It has been shown that the level or exertion required for the Rhabdo is dependent on individual fitness. In fact, as little as 50 sit-ups a day for 5 consecutive days led to a case. Studies of NYC Firemen have shown that there is an inverse relation between risk or Rhabado and fitness level. Therefore, risk is difficult to determine as a group and needs to be considered with patient history in mind.

In addition to exertion, non-exercise risk factors can combine to increase the chance of occurrence. For instance, metabolic myopathies and Malignant Hyperthermia, both of which can be inherited, may increase risk when combined with nominal exertion. Furthermore, viral illness such as Epstien-Barr, herpes simplex, and parainfluenze may increase risks. Finally, the US Army has shown a 200-fold increase in risk in those with sickle cell traits.

While medics in the tactical environment may not have the capabilities to diagnose Rhbado, they can manage it if the patient’s exam leads one to believe it is an issue. However, only 50% of patients present with the classic signs of myalgias, tenderness or swelling of muscles, dark urine. Therefore, if a medic suspects Rhabdo, s/he needs to treat the acute risk of damage to renal tubes. To do so, it is suggested that one needs to use a saline infusion producing an ideal urine output of 200 ml/h. Of course, drugs and buffering with alkalization is optimal, but that is beyond the scope of most medics, and it is probably not needed for support during transport to higher medical care.

The best treatment is, as always, prevention in the tactical environment where resources are precious and limited. Risk ought to be mitigated by ensuring members of your team are in good shape. If they posses any of the listed non-exertional risks, they need to be instructed to use caution when performing tasks and operations.

For more detailed information, see this paper: Rhabdo_Military_Pers.

Hemostaic Primer

We often get questions regarding hemostaics:
Which is the best?
How do they work?
What is the mechanism of action?

The TCCC recommendation of Combat Gauze (TM) has clouded the issue of effectiveness with respect to other available agents. That is to say, there are others on the market that were just as effective in studies that were not chosen. Hopefully, the attached study summarizes the pros and cons of most available agents.

TCCC Hemostatics JRAMC 2010

Lessons Learned: “Four Hours of Tourniquet Time”

Below is an excerpt from a lessons learned compilation titled “First to Cut: Trauma Lessons Learned in the Combat Zone.” Though it is geared toward FST surgeons and forward medical providers, some of the lessons are applicable to tactical medics and mountain rescue. The larger take-away point is that the physiology occurring distally to a tourniquet applied for a long duration needs to be considered when changing or loosening, especially in environments where medical care may be limited (e.g., Third World).

    “Four Hours of Tourniquet Time”

    “26 y.o. male with foot traumatic amputation and
    multiple frag wounds to the right leg with a high thigh
    field tourniquet in place. Arrived to the CSH with SBP of
    100 HR of 120. we had no report on duration of the
    tourniquet. We took down the tourniquet and he promptly
    coded. We put the tourniquet back up, intubated him and
    gave him fluid and bicarb and he came back. We found
    out later that the tourniquet had been in place for over 4
    hours….”

    The use of tourniquets – while rare in civilian trauma is
    very common in combat injuries. Tourniquets are the
    number 1 instrument that a medic can employ to lower the
    KIA numbers. The use of tourniquet with application until
    the absence of a distal pulse by default causes distal
    ischemia. Release of a functioning tourniquet after several
    hours can result in the release of acidic fluid and potassium.
    The patient intubated and without a head injury can be
    briefly hyperventilated. Before taking down a long
    duration tourniquet make sure the patient is well hydrated,
    resuscitated, adding an ampule of sodium bicarbonate or
    THAM can prophylax against the release of “bad humors”,
    lactic acid, and potassium. Also release the tourniquet
    slowly – if the rare arrhythmia arises re–employ the
    tourniquet and retry after further bicarb and fluid. If the leg
    is necrotic remember “life before limb” and perform an
    amputation.

    Lessons Learned:
    –Prolonged tourniquet times can result in the release
    of acidotic fluid and hyperkalemia
    –Perform 4 compartment fasciotomy with all lower
    extremities with significant tourniquet times