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

The SOF Tactical Tourniquet has always been TCCC approved, but until recently, it has been overlooked when it comes to official TCCC instructions and guides. Here is the link to the most recent Care Under Fire PowerPoint produced by the TCCC board that outline the instructions. Furthermore, the second link below has many other training aides for all phases of tactical medicine.

CUF Link

General TCCC Links

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)

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

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.

This video is a supplement to training and is neither comprehensive nor a replacement for proper instruction.

A surgical airway/cricothyroidotomy is the advanced airway of choice in combat, due to the types of injuries encountered. Severe maxofacial trauma secondary to blasts are common and may require more invasive treatment when neither the recovery position nor NPA nor King Oropharyngeal Airway (King-LTD) will suffice. It is important to note that only airway management is generally best left to the Tactical Field Care (TFC) phase of treatment. Furthermore, less than 1% of trauma casualties require an airway, so prudence is required when deciding to intervene. The indications and contraindication are as follows:

Indications:

–Airway obstruction due to maxillofacial trauma that cannot be corrected by positioning or a nasopharyngeal airway
–Anaphylaxis that is or is about to compromise the airway
–Inhalation burns injury
–Where other means to secure the airway have failed

Contraindications:

–Airway can be maintained by other means

Please note that we illustrate a vertical incision instead of the traditional horizontal, because we feel it is the preferred method in the tactical environment. First, a vertical incision minimizes the risk of involving (e.g., cutting) the vascular structure of the neck. Second, it creates a larger “window,” thereby simplifying landmark identification. Finally, a vertical incision allows one to select a different location above or below the initial site, if one should misplace the initial cut, due to lack of familiarity with the procedure.

Below you will find an article published in Military Medicine. It argues that traditional ways of providing a surgical airway in a tactical environment are flawed. Therefore, the authors continue, a new approach is needed. Three-step Cric

Objective: Surgical cricothyroidotomy is the airway of choice in combat. It is too dangerous for combat medics to perform orotracheal intubation, because of the time needed to complete the procedure and the light signature from the intubation equipment, which provides an easy target for the enemy. The purpose of this article was to provide a modified approach for obtaining a surgical airway in complete darkness, with night-vision goggles. Methods: At our desert surgical skills training location at Nellis Air Force Base (Las Vegas, Nevada), Air Force para-rescue personnel received training in this technique using human cadavers. This training was provided during the fall and winter months of 2003-2006. Results: Through trial and error, we developed a “quick and easy” method of obtaining a surgical airway in complete darkness, using three steps. The steps involve the traditional skin and cricothyroid membrane incisions but add the use of an elastic bougie as a guide for endotracheal tube placement. We have discovered that the bougie not only provides an excellent guide for tube placement but also eliminates the use of additional equipment, such as tracheal hooks or dilators. Furthermore, the bevel of the endotracheal tube displaces the cricothyroid membrane laterally, which allows placement of larger tubes and yields a better tracheal seal. Conclusion: Combat medics can perform the three-step surgical cricothyroidotomy quickly and efficiently in complete darkness. An elastic bougie is required to place a larger endotracheal tube. No additional surgical equipment is needed.