We have discussed the changing thoughts regarding the sign and symptoms of Tension Pneumothorax in the past (see here: Rethinking Tension Pneumothorax). Although this study was broad, it did not address in detail the implications of different locations of one of the more popular treatments of tension pneumothorax: needle decompression. Due to an increased incidence of iatrogenic effects of improper needle placement, one of the recent topics of discussion among TCCC trainers has centered around locations (i.e., anterior vs lateral) of needle placement. Improper anterior placement in the mid-line direction can led to severe vascular injuries. Some have advocated for moving the primary location for needle insertion to the lateral location to mitigate iatrogenic effects. This location, however, raises other issues, specifically chest wall thickness in comparison to the anterior location, even as needles have increased in length.

A recent study published* in Academic Emergency Medicine seeks to answer one of the questions that have emerged from the debate by identifying the optimal site of needle insertion with respect to anterior wall thickness limitations. The results are interesting. Average chest wall thickness at the right side anterior second intercostal space, lateral forth and fifth mid-axillary locations were 46.4 mm, 53.8 mm and 63.7 mm, respectively. When considering the one factor of chest wall thickness as it relates to successful penetration of the plural space, the researchers concluded, the anterior location is superior. Furthermore, attempting to overcome the increased chest wall thickness at the lateral mid-axillary locations by using a longer catheter is risky, for it increases the risk of damaging surrounding vascular structures.

While this study does not address the larger issue of practitioners misplacement at the anterior location, it does illicit and attempt to answer an important question of impulsively changing training doctrine to emphasize the lateral location.

*Anterior Versus Lateral Needle Decompression of Tension Pneumothorax: Comparison by Computed Tomography Chest Wall Measurement by Sanchez, Leon, MD, MPH, et al. Academic Emergency Medicine 2011; 18:1022-1026 by the Society for Academic Emergency Medicine

In a recent article published in the Journal of Trauma Injury, Infection, and Critical Care, the authors analyzed the effect of life-saving interventions (LSI) performed by combat medics and other forward providers. The medical practitioners in the study were arranged in an EMS style hierarchy under a medical director, with the majority of medics trained to the EMT-B level, in addition to supplemental training in TCCC-approved LSI procedures. Additionally, they analyzed outcomes with an eye toward the applicability of more advanced care in the form of Remote Damage Resuscitation protocols. As summarized below, they found that forward deployment of blood products would be beneficial if the logistical and scope-of-practice concerns could be addressed. In the limitations section of the study, they concede that certain biases might have affected the outcome. They note, for instance, “[t]he differential impact of transport time from point-of-injury to surgical facility arrival is worth considering.” Time from injury to point-of-injury treatment, time between request for evacuation to arrival of transportation, and time from extraction to the study facility all affected the outcomes, some of which were unknown in retrospect.

Although the authors did acknowledge in the conclusion that LSI need to be performed sooner, they unfortunately continued to argue that their notional blood protocol would have been beneficial. This is despite the fact that the majority of LSI were preformed by PA-level practitioners or higher, which is the major concern, because that indicates that urgent and priority patients were evacuated without LSI. It is difficult to surmise why LSI were not performed sooner, due to the nature of record keeping and retrospective studies. Perhaps tactical considerations dictated transport before treatment, or casualties deteriorated during evacuation. Nonetheless, early treatment is paramount, so training might possibly the more important to allocate resources to than blood protocols. Technology is an exceptional adjunct to the basics, but medics must have a foundation upon which to build.

Background: To analyze casualties from the Camp Eagle Study, focusing on
life-saving interventions (LSI) and potentially survivable deaths.

Methods: Retrospective cohort of battle casualties from a forward base engaged in urban combat in Central Iraq. Medical support included emergency medicine practitioners and combat medics with advanced training and protocols. LSI were defined as advanced airway, needle or tube thoracostomy, tourniquet, and hypotensive resuscitation with Hetastarch. Cases were assessed retrospectively for notional application of a Remote Damage Control Resuscitation protocol using blood products.

Results: Three hundred eighteen subjects were included. The case fatality rate was 7%. “Urgent” (55) or “priority” (88) medical evacuation was required for 45% of casualties. Sixty-one LSI were performed, in most cases by the physician or PA, with 80% on “urgent” and 9% on “priority” casualties, respectively. Among survivors requiring LSI, the percentage actually performed were airway 100%; thoracostomy 100%; tourniquet 100%; hetastarch 100%. Among nonsurvivors, these percentages were 78%, 50%, 100%, and 56%, respectively. Proximate causes of potentially survivable death were delays in airway placement and ventilation (40%), no thoracostomy (20%), and delayed evacuation
resulting in hemorrhagic shock (60%). The notional Remote Damage Control Resuscitation protocol would have been appropriate in 15% of “urgent” survivors
and in 26% of nonsurvivors.

Conclusion: LSI were required by most urgent casualties, and a lack or delay in their performance was associated with increased mortality. Forward deployment of blood components may represent the next addition to LSI if logistical and scope-of-practice issues can be overcome.

(J Trauma. 2011;71: S109–S113)

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.

Rubber band tourniquets (RBT) have gained popularity in the law enforcement community over the past 24 months. The compact size and nominal cost make them attractive to cash-strapped, and over loaded with respect to equipment, LEOs. Furthermore, as LEO commanders seek to outfit their personnel with live saving equipment while grappling with budget constraints, RBTs seem like a viable option. However, upon further consideration, they may not be the BEST choice due to inherit dangers of RBTs with regard to function and application.

The function of RBTs is simple: one applies it proximal to the injury, wrapping it around the limb until hemorrhage control is achieved, using the elasticity of the rubber to create greater circumferential pressure with each wrap. Initially, this seems easy and straight forward. However, due to the nature of elastic wraps one must be cautious when using one as a tourniquet, due to the difficulty in controlling the applied pressure. As noted in the Journal of Medicine and Biomedical Research, “[t]he pressure induced by the rubber bandage increases at a rate of 3 to 4 times the initial pressure when the bandage is stretched after each wrap.”(1)(3) This is dangerous due to the shearing effect generated on the underling tissues, specifically the nerves. In fact, Graham et al found that at above 300mm Hg shearing forces increased exponentially.(2)(3) With RBTs this is concerning as “[t]he pressure applied to the limb could easily exceed the safe limits and put the limb at risk of complications because the rubber bandage is capable of generating pressures in excess of 1000mmHg beneath it.” “At such extremely high pressure,” Ogbemudia continues, “neurovascular damage becomes likely and makes the use of the RBT relatively unsafe.”(1)(3) He does explain how, in a controlled environment such as a surgical suite, a RBT can be made safe by placing a BP cuff under to monitor pressure. Obviously, this is not optimal in the tactical environment.

There are also difficulties faced when applying a RBT with respect to generating adequate circumferential pressure to stop arterial hemorrhage. Applying a RBT to an extremity, especially an upper limb, mobility is required in order to wrap it around the limb a sufficient number of times. If there has been any bone involvement, this may be an excruciating affair. Furthermore, if, due to pain associated with application, the casualty does not achieve hemorrhage control, he must then un-wrap the RBT multiple times, then re-wrap it in the hopes of achieving enough pressure. Unfortunately, the reverse is true. In an attempt to generate enough pressure, one may generate too much unknowingly. Compared to a windlass-style tourniquet, for instance, one must only turn the windlass an additional 180 degrees, thereby tightening it to achieve more tension. Tourniquets issued within DOD, unlike RBTs, are difficult to over tighten when used one-handed and according to the manufacturers’ directions due to the nature of the webbing and knot interface.

Finally, when compared to standard tourniquets used by the majority of DOD and many state and local LEOs, a RBT has multiple variables that must be considered that relate to the pressure generated. In this case, variables are defined as inconsistencies between casualties and application each time a tourniquets is used. They are compared as follows:

Windlass style tourniquets have 2 variables:
1) limb circumference;
2) degrees rotated.

RBT tourniquets have 4 variables:
1) the percentage of stretch applied with each turn (composition and elasticity of the material, which affect the restoring force of the polymers);
2) the number of layers of the RBT;
3) the degree of overlap;
4) the circumference of the limb.

In the end, a RBT can be used as a field tourniquet. However, it is not the best option for LEOs. The benefits of cost savings do not outweigh the potential problems and risks associated with rubber band tourniquets.

References
[1] Ogbemudia A et al. Adaptation of the rubber bandage for the safe use as tourniquet. Journal of Medicine and biomedical Research 2006; Vol. 5 No. 2 pp-69-74.
[2] Graham B et al. Perinerual pressures under the pneumatic tourniquet in the upper and lower extremity. Journal of Hand Surgery 1992: 17B: 262-6.
[3] McEwen J. A. and Casey V. Measurement of hazardous pressure levels and gradients produced on human limbs by non-pneumatic tourniquets. Accessd at
http://www.tourniquets.org/pdf/CMBEC%2032%20McEwen%20and%20Casey%20Tourniquet%20Paper.pdf

We just received a copy of a new book covering the elements of tactical medicine. Check it out!

Tactical Medical Essentials Link

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?

We are pleased to announce an upcoming educational opportunity. On Thursday, October 14, 2010, the Texas Health Presbyterian Hospital will be hosting a conference titled, “Update on Tactical Medicine Concepts and Controversies.” This is a great opportunity and we will be attending.

Tactical_Medicine_Web_Brochure

Conference Description:
This conference will address those new and innovative interventions, products and techniques whose implementation at the point of wounding (POW) will allow for a more stable and viable patient upon arrival at the tertiary facility and, hence, improved longterm outcome. Though originally designed for the military theater, Tactical Combat
Casualty Care (TCCC) concepts are rapidly being adopted within the civilian medical and law enforcement communities as they are asked to respond to terror incidents at home. Columbine High School, Virginia Tech and terror incidents in Russia and India are only a few examples of the world in which we live. This conference is as relevant to
law enforcement (local and federal) and medical first responders as it is to the Soldiers and Marines on the battlefield. It is also relevant to physicians, nurses and other care providers, both civilian and military, who have a need for familiarity with current medical care techniques in the tactical environment.

In an age when hemostatic agents and pocket-sized BP cuffs monopolize most conversations regarding combat casualty care, a command of the basics is being lost. While the abundance of choices of pre-made kits addressing the majority of field-treatable injuries reduces the chance of needing to improvise, one ought to have a command of the basics using available materials.

A medic cannot have a more basic piece of kit than a triangular bandage. Therefore, we are having a contest to encourage submissions of different ways to use a triangular bandage to treat combat trauma. The details are as follows:

Prize: $200 in free Tac Med gear

Submission Format: Either submit a description to the comments section or email them to alan@tacmedsolutions.com. How-to videos are welcomed, but not required. We will be filming the most unique and helpful techniques for the blog.

Deadline: All submission must be in by 1 MAR 2010. We will announce the winner by 15 MAR 10. Due to concerns with operational anonymity, we will request your approval before sharing your name.

As mentioned in an earlier post regarding Level 1 kit, you must pack your medical gear to reflect the mission requirements and constraints. Here are some considerations when packing your Level 2 gear:

1) Pack supplements to Level 1. For instance, medics may need more bandages and tourniquets.

2) Pack for Tactical Filed Care phase of treatment. In this phase, you may need:

A. Drugs (e.g., Toradol) and associated items (e.g., syringes, heplocks)
B. Splinting material
C. Evacuation Platforms (e.g., poleless litters or a Foxtrot Litter)
D. Fluids
E. Needle Thoracostomy items
F. Hypothermia Prevention
G. Casualty Equipment Bag
H. Casualty Documentation

3) An aid-bag for the above items. Err on the side of too small, as carrying a “tick” on your back might be more of a burden than an asset, depending on the mission. That is your call.

The above serves as a framework. We will cover Level 3 in the next post.

Historically, tension pneumothax has been the 2nd leading cause of preventable death on the battlefield. Therefore, this is an important skill and is being taught to medics at the lowest level of care. However, as with all procedures, risks are involved. Feedback from the field has indicated that medics are performing this procedure too often and TOO medial, causing multiple complications.

The above video covers the hazards of a needle decompression. Below you will find a brief review of indications, contra-indications, etc. As always, please follow local protocols.

INDICATIONS:
Needle decompression is indicated for the treatment of:
A. Tension pneumothorax and / or
B. Tension hemopneumothorax

CONTRA-INDICATIONS:
A. Chest decompression is indicated in the field only in the face of a life-threatening
tension pneumothorax. In that situation, there are essentially no contraindications since
the only alternative is almost certain death.

CAUSES OF TENSION PNEUMOTHORAX:
A. Blunt force trauma to the chest that ruptures a portion of lung tissue
B. Fractured rib that punctures the lung tissue
C. Spontaneous pneumothorax for no apparent reason
D. Conversion of a simple pneumothorax to a tension pneumothorax by positive pressure
ventilation as with a bag-valve mask device etc.
E. Open pneumothorax that is covered and left unattended developing into a tension
pneumothorax

SIGNS/SYMPTOMS
A. Chest pain
B. Severe respiratory distress
C. Tachycardia
D. Hypotension
E. Decreased or absent breath sounds on affected side

LATE SIGNS / SYMPTOMS:
A. Cyanosis
B. Distended neck veins
C. Tracheal deviation away from affected side

(Source: Canadian Tactical and Operational Medical Solutions)

COMPLICATIONS:
A. Creation of pneumothorax where none existed previously
B. Laceration of lung tissue
C. Bleeding from laceration of intercostal blood vessels
D. Severe pain to conscious patient (since this is life-threatening, the procedure must be
continued )
E. Local hematoma
F. Laceration and/or puncture of the heart