|
|
SITREP: Best of 2008Welcome to our end of year issue. For this issue, we are reprinting our favorite stories from 2008. It was a tough call for us to decide which we thought were best. There were so many that helped to contribute to our first year success. We thank all of you who did contribute. Feedback helps us the most and we encourage you to continue to provide us with your feedback. If you have a story would like to contribute, let us know. The stories we decided to go with include the care under fire article by Mike Killman, the article on ITS pants, the story by TJ on JTM Vegas, and lesson learned by Dr. Phelps. As a bonus, we added the timely article by tax attorney Jane Burno. This made for a slightly larger issue than usual, but you’ll enjoy it. It is Thanksgiving weekend as I write this. I’m still watching the reports come out of Mumbai. It reminds me to be grateful for all that I have. No matter how bad things get if you can think there is something to be thankful for. I recommend that you take some time each day just to reflect on gratitude. It may be that you have another day above ground and escaped the dirt nap. That’s enough to start to focus on gratitude. Doc Lee TCCC Update 2008:Here is a link to the Tactical Comabat Cauaslty Care 2008 Updates to the TCCC 2006 guidelines. http://www.usaisr.amedd.army.mil/tccc.html# Once you get to this page, click on
Field Practice: Care Under FireAn Approach to Training by Mike Killman Since Care Under Fire’s (CUF) inception in the mid-1990s its principles and techniques have been thoroughly integrated into the tactical/medical response of the modern warfare combatant. The ongoing CUF experiences of our armed forces and civilian protective security detail (PSD) contactors in Iraq and Afghanistan continue to refine this crucial element while ensuring that both elements maintain a tactical advantage and minimize loss of life. The many lives saved in these two conflicts by the immediate application of tourniquets to arrest massive extremity hemorrhage alone attests to efficacy of one of CUF’s main principles. Furthermore, CUF teaches an action sequence for both the injured and uninjured, which outlines an effective and goal-oriented response while engaged in combat. CUF is easy to teach and comprehend; however, experience has shown that we do not integrate it into all aspects of training—often teaching it as a one-time class separate from our many other PSD drills. We are good at walking the box, vehicle evacuation and attack on principle drills, but throw in a man-down, or two, or three and some teams do not perform as well as they could have (or believe they will) had they trained a little harder and added CUF scenarios of varying degrees of difficulty to their PSD drills. Although a Care Under Fire for PSD outline is attached, it is not the objective of this article to teach Care Under Fire, as there are many references available in both print and online that already do this well (just search Care Under Fire or Captain Frank Butler). Rather, the objective is to discuss how CUF can—and needs to be—integrated into an overall PSD training package. Moreover, it stresses the importance of establishing a complete and logical training approach that eliminates the ineffective, frustrating and uninspired “check the box” syndrome that often infects training. From my observation, training is often disjointed. Individual and collective tasks are not integrated into more complex, memorable and dynamic scenarios. Too often, people walk away from training frustrated and confused. Sadly, valuable training time can deterorate into periods of frustration and anger fueled by ego and a lack of focus as teams argue about what tactics are better, or this is the way we did it in the SEALS, SF, Rangers, Recon, Marines, PJs, SWAT, FBI, Buttplate, Iowa PD, ad nauseam. To eliminate this bane of training it is imperative that goal oriented thought and logical sequencing be applied when establishing a training outline. Individual tasks must be mastered, and then collective tasks until everything can coalesce into dynamic, complex scenarios that bind all the training evolutions together. Additionally, we must look at the twin pillars of task selection: frequency and criticality. If a task is to be performed frequently, it goes without saying, that we must master this skill, however, we must also consider criticality. If a task is not performed frequently but may be critical for mission success, or may mean the difference between life and death, than this is a critical task. CUF is a critical (extremely critical) task—hopefully not a frequent one—and needs to be trained until it becomes second nature for PSD members. It should not just be, “a class we had last month.” Even though the fundamentals of CUF remain unchanged regardless of the unit’s profile, medics and leaders at all levels must consider their unit’s unique requirements and constraints while planning their CUF training. For example, high-profile teams operate differently than low-profile teams. Isolated outlying teams may have different assets, requirements, restrictions and SOPs than city teams which may be based adjacent to higher medical care facilities. Each team must adapt their response accordingly without violating fundamental principles. It remains the responsibility of each team to evaluate their capabilities, strengths and weaknesses to formulate the best training plan to ensure that their response is as effective as it can be when rounds are being exchanged. Before teaching a Care Under Fire class, schedule training time for PSD drills. There is no benefit in adding CUF scenarios to these drills if the team is not able to perform the basics effectively. The training focus should be on the integration of CUF into a scenario and not hashing out the elements of a particular PSD drill. (Logical sequencing of training is chronology: driving to the venue; vehicle down with vehicle evacuation; vehicle or vehicles down with hard pointing; walking the principle into the venue; extracting the principle under duress while on venue) Medical Classes: (Logical sequencing is parts before the whole) Integrated Drills: Training time requirements and tasks may vary between teams due to mission profile and experience. However, experience has shown that all teams benefit from at least a good review of their SOPs prior to integrating CUF scenarios into the drills. Additional medical training should focus on Tactical Field Care in the “warm zones” and “cold zones.” An abbreviated patient survey and trauma management modalities appropriate to sustaining casualties for extended time periods in accordance with your CASEVAC response and evacuation times should be taught. Teams close to a hospital or with quick CASEVAC response may get by with less than a team running out in no-man’s-land. Train appropriately. There will always be discussions (often arguments) about the best way to do something and which tactic is the most appropriate for a particular circumstance, but the goal should be to minimize these differences while training. When possible, these matters should be resolved, sand-tabled, chalk-boarded, or whatever else you want to call it, before heading out to train. Keep in mind: as long as principles are not violated, tactics may come in a variety of sizes and shapes. Leave your ego at home, train hard and train effectively. Additional Considerations: Regardless of what anyone tells you, have them practice all of the basic medical skills as often as possible. Make it interesting and challenging by adding them into scenarios, practicing speed drills, or by changing environmental variables (do them in the dark; in a little-bird; in a crammed vehicle on the move, etc.). Too often I have been told that “we have had this class before” and then witness one or two guys that cannot apply an effective dressing, or use a tourniquet properly—train the basics. Lastly, add in all the “what ifs” that you experience during training or are unique to your mission, or unfortunately have experienced firsthand. Under stress we revert to what we have trained to do, not what we would like to think we would do. During a complex attack the Shift Leader and Tactical Commander have a myriad of tasks they must complete. Having already gone through this CUF thought process will enable them to make these decisions in the shortest amount of time and in the most efficient manner. CUF will allow team members to remain engaged in combat while addressing the injured and accomplishing the mission. I am sure this brief article does not cover all aspects and “what ifs” of CUF. What I do hope that it has done is inspired those of us that are not fully training to our capacity, or worse, not including CUF in our everyday PSD drills to make sure that this critical task is mastered. Remember, we will not rise to the level of our expectations but rather; we will sink to the level of our training. Let’s get our training in line with our expectations before the rounds start flying. Following is a handout I have put together and used while teaching CUF. It was not designed to be stand alone teaching tools but rather as a bullet point teaching sheet for students to follow during training and expound upon later as they run through their own thoughts and experiences. Please feel free to correct, add-to, or modify as necessary in accordance with your needs and mission profile. The only goal remains is that we bring each other safely home. Train smart, train hard, and train effectively. CARE UNDER FIRE (CUF) for the PSD Care Under Fire Tactical Considerations: Team Leader makes decision on how best to retrieve the wounded. He has several basic options: Further Considerations: What to do with the Motorcade Movement to Downed Man Care Under Fire Medical Considerations: • Airway intervention, if needed, is limited to opening the airway and nasopharyngeal airway. Stop life-threatening hemorrhage with a tourniquet. Get the patient to warm or cold zone and initiate higher medical care, ground evacuation or call for CASEVAC. In a nutshell: SMAG • S— superior firepower and smoke Mike Killman is a long time Special Forces Medic who has instructed a generation of SF medics and paramedics. He currently works extensively in the private security industry. Gizmos and Gadgets: An Interview with Dr. Kieth Rose inventor of the ITS pantsby Jon Holmes A great deal of buzz has been created by the new tourniquet clothing marketed as the Integrated Tourniquet System (I.T.S.) pants and coat. We invited the inventor, Dr. Keith Rose, to provide us an interview to explain this new product. Dr. Rose could you please start out by telling our readers about your training and background? I am trained in General Surgery, Plastic Surgery, and Burns and Critical Care. I was in the Army on a Forward Surgical Team (Honorable Discharge 2002). I am a member of the American College of Emergency Physicians. I currently am an instructor at the International School of Tactical Medicine and the Tactical Medical Consultant for Blackhawk’s Special Operations Division. I also work with Cure International training third country national surgeons in Afghanistan and Pakistan. I have provided tactical medicine support and consulting in Afghanistan, Iraq, and Central and South America.
I was involved in an incident overseas several years ago while doing humanitarian work. A man was injured in an attack and trapped in an up-armored vehicle. He had taken a piece of shrapnel through his thigh and was bleeding profusely. Due to the twisted shape of the damaged vehicle we were unable to get to the man immediately and he bleed to death in 5 minutes from his thigh wound. This man was awake and alert initially and his leg was trapped in the twisted wreckage. This got me to thinking over the next several months. Had he had a pre-placed tourniquet he could have stopped his own bleeding.
The tourniquets are built into the clothing in soft mesh channels. The tactical nylon and carbon fiber windlass mechanism is lightweight and concealed. When a person is injured he can immediately lift a flap, flip the carbon fiber bar, and activate the tourniquet using the windlass mechanism. Due to the design, the tourniquet provides an effective occlusion of the blood flow without removing any equipment or garments in seconds.
The pre-placement of tourniquets on the extremities by operators can cause unwanted constriction of the extremities as the operators move and there muscles swell from the increased blood flow of exercise. They can also slip and catch on environmental hazards. I had one SF soldier from Australia tell me how his arms gradually went numb on an operation when he pre-placed tourniquets and he had to remove them at an inopportune time. The Blackhawk ITS is built into the clothing and does not slip or constrict the extremity under any conditions. I must be manually activated to achieve occlusion. It does not catch on environmental hazards due to its internal construction in the garment.
There are a total of 25 subjects in the study currently. (See attached study in this issue)
There are several operators using the ITS currently in the field. To my knowledge no one has had to activate the system in a tactical or emergency situation.
Very positive feedback. The current operators who use the ITS tell me “they won’t leave home without it”. I just returned from Afghanistan and one of the guys wearing the ITS (Former Australian SF now working as a contractor) told me he wears his pants and shirt everywhere. He stated it gives him the same peace of mind that body armor does.
Blackhawk is a company owned and run by first class operators for military, contractors, law enforcement and outdoor enthusiasts. They have an intimate knowledge of this system. They know it well and the strength of the ITS is it’s KISS simple.
Extremity hemorrhage is the number one cause of preventable death in the tactical environment today. The Blackhawk ITS effectively addresses this issue and will save lives. It’s just that simple.
Blackhawk.com We would like to thank Dr. Rose for his time. If you would like to post any comments or questions, please do so at vighternews@vighter.com. (Ed note: I have worn a pair of the pants. The material is slightly heavier than my regular 511's, but I found them comfortable and easy to move around in)
Training: JTM Las Vegasby John Trujillo I recently attended the JTM Las Vegas SOF Medic Refresher course located on Nellis AFB. I was given an option of several medical courses to attend and chose JTM primarily because it was the only course to provide the Paramedic Refresher Course that I need to recertify as an EMT-P. Surprisingly, I found that they offer the best tactical medical course I’ve ever witnessed, a claim I can make with some authority. I graduated the 18D, Special Forces Medical Sergeant’s course, in 1991. Consequently, I have been exposed to numerous ATLS courses, a.k.a. Traveling Goat Show. As well as a Detachment Medical Sergeant, I have served as an instructor for the SOMTB, OEMS and TMI. In addition, I assisted the Medical School of Georgia in initiating the basic EMT course for the FBI’s Hostage Rescue Team. While all of these courses are impressive in their own right, they don’t fully meet the criteria for tactical medicine. OEMS, for example, is an advanced operational medical course that certainly melded my pre-med degree and my 18D training but any “tactical” experience offered is merely theory. JTM’s SOF Medic Refresher course has a completely different approach. The “Care Under Fire” portion of the course takes on a life of its own and is what separates JTM Las Vegas from the other TCCC courses available. To provide realistic threat, a significant number of the field training exercises were executed with rapid-fire paintball guns. Forget the perception of a bunch of overweight civilian Bubbas playing weekend Rambo; these scenarios are no joke. Throw in a little friendly inter-service rivalry and a whole lot of personal pride from a bunch of competitive, type-A, mission oriented, SOF soldiers with unit reputations to protect and you get Marcus Welby in a wild west version of a Texas Cage Match. One of the most innovative practical exercises I have ever participated in was the “Box of Death.” I choose not to divulge the details of this exercise, not only for the sake of brevity, but also to allow subsequent classes to fully benefit from this unique training experience. During this exercise, two-men teams rotate through a series of scenarios requiring them to fight their way to their patients. They must then develop and implement a plan of action to treat and recover the patients while under fire. The realism of these physically and mentally demanding conditions is the keystone to the JTM Las Vegas SOF Medic Refresher course. “Scene Safe” is not just a rhetorical catch phrase. These scenarios provide students with immediate feedback regarding mission success or failure. The “Sensory Deprivation Scenario” is another outstanding practical exercise that JTM Las Vegas has incorporated into the course. This portion of the training involves patient assessment, treatment and recovery while in an environment of low light, high noise and other simultaneous distractions. Students are subjected to 45 minutes of chaos while cold and wet. This is in stark contrast with other medical courses that place the simulated casualty in a supine “Vince Foster” position. Requiring medics to operate in a realistic “Murphy’s Law” environment with multiple casualties reinforces the need for sequential assessment. The JTM is a “run what ya brung” course. Theory and discussion both have a place in medicine but not in the tactical setting. At JTM you can provide any treatment you want as long as you have the equipment and can demonstrate you know how to use it. Prior planning and preparation are essential for real world mission success and is therefore also essential for JTM scenario success. The instructors and a vetted student body are significant components to the success of the JTM course. The staff, which includes paramedic instructors, JSOC physicians and firearms instructors, are all experts in their fields. Their intent is to fully prepare personnel going into harm’s way. Students come from diverse military and contractor backgrounds with recent real world experience. The interaction of these students enhances the learning experience. JTM Las Vegas is owned and managed by a former PJ. He has created the mindset that focuses on realistic performance under fire. This course is made up of and designed for soldiers/contractors going to hostile ground to rescue their brothers and sisters in arms. In addition to the valuable training, I received the latest updates in tactical medicine from lessons learned in the sandbox. These lessons were presented in a captivating and challenging manner. The JTM SOF Medical Refresher course provided the requisite refresher training to recertify as an EMT-P. More importantly, the training was conducted in a tactical environment that not only tested my medical skills, but also challenged my performance under realistic situations. This course is designed for those with significant tactical and medical backgrounds. It proves to be both challenging and interesting throughout. I highly recommend this course to qualified individuals looking to enhance their ability to work under fire. Special Report: An Interview with Overseas Tax Expert Jane Bruno, JDby Jeff Lee Jane Bruno, JD, LLM is a tax lawyer who specializes in overseas taxes. Tax season recently ended, but this seemed like a good time to prepare for next years taxes. Her book is available for purchase at her website www.expattaxpreparation.com . The following is our interview with her. Ms. Bruno, thank you for allowing this interview. Can you please start off by telling our readers your background and how you developed your expertise in overseas taxes? My background is in law. I graduated from the University of South Carolina Law School ages ago and several years later went to George Washington University Law School for my Master’s in Tax Law (LLM-Taxation). Shortly after that, my husband, who worked for the US State Department, was assigned to Germany and we moved there. While overseas I got interested in the tax problems faced by “expats” and eventually got a job as a Taxpayer Service Representative at the IRS office in Bonn. As we continued to move overseas, I worked with many Americans preparing tax returns and doing consulting. Eventually, I decided to write a book that would outline the basic principles of US taxation of Americans overseas. It has first published in 1998 and a new edition is available each year. The Expat’s Guide to US Taxes can be obtained from my website, www.expattaxpreparation.com Can you explain to us what is the Foreign Earned Income Exclusion? Congress created the foreign earned income exclusion many years ago as a way of encouraging American participation in the global economy. It allows a certain amount of foreign earned income to be excluded from tax each year provided certain requirements are met. Is there a limit on the amount of money that can be tax-free? Does this limit change from year to year? The maximum amount has been increasing for the last several years. In 2007 it was $85, 700 and in 2008 it will be $87,600. What are the requirements to be considered tax-free? In order to claim the foreign income exclusion, the income must be earned as salary or self-employment income (it cannot come from investments, a pension, an annuity, etc.). And the taxpayer must have his/her tax home in a foreign country and meet either the physical presence test or the bona fide residence test. We’ve all heard about the 330 days of 365 that you need to be outside the US to be tax free. What is the exact number of days and does it have to be in one tax year or more? The physical presence test is an objective test and requires the taxpayer to be physically present in a foreign country for at least 330 days in a 365 day period. There is a lot of flexibility in this test, including allowing a partial exclusion of foreign income if the taxpayer moves overseas in the middle of the calendar year. However, it does limit the number of days the taxpayer can be in the US. If you are required by your employer to return to the US for training, meetings, or other business does that count against your 330 days? Being in the US for work-related purposes will count for the 35 days. For examples on how days are calculated, I refer you to the IRS Publication 54 (www.irs.gov), which has a section on this subject. I also cover it in my book in some detail. Can you explain the bona fide residence test? The bona fide residence test is a subjective test in which a number of factors are considered to determine if the taxpayer truly has made the overseas location his residence. The one OBJECTIVE factor is that the taxpayer has to be in the foreign country for a full calendar year before he/she can be considered a bona fide resident at all. Once that has occurred, the IRS looks at whether the taxpayer claims to be a resident of the foreign country for foreign tax purposes, what ties there are to the country (such as bank accounts, owning a home, etc.) And if this test is met, there is considerable flexibility in the amount of time the taxpayer can spend in the US. Some taxpayers will spend the summer in the US with their families or make frequent trips for business or pleasure without losing their ability to claim the foreign income exclusion. Can you tell us about the foreign housing exclusion? Does it apply if your employer provides your housing? The foreign housing exclusion is available if the taxpayer rents a place overseas and pays out-of-pocket or is reimbursed by the employer. In the latter case, however, the reimbursement will be considered income for purposes of the foreign income exclusion. If the employer provides housing for the convenience of the employer and not as a “perk” to the employee, then the value of the housing is NOT included as income and is NOT available for the housing exclusion. The calculation of the amount of housing exclusion is quite complicated and depends on the location of the taxpayer (some areas of the world with higher cost-of-living are allocated higher exclusions) as well as determination of the “housing amount” which is a base figure that has to be exceeded before any exclusion is allowed. I have a pretty comprehensive example of how this works on my website, www.expattaxpreparation.com, under the heading “Tax Info for Expats”. Where can these tax laws be found? For sources of information, I recommend IRS Publication 54 and, of course, my book. There are also a number of articles I have written on various aspects of taxation of Americans overseas for American Citizens Abroad (www.aca.ch). I believe they can still be accessed at that site. For a study of the tax law itself, I suggest starting with Internal Revenue Code Section 911. Are there any State tax laws that we should be aware of or which States have applicable tax laws that benefit overseas employees? As far as state tax laws, there are a number of approaches. Some will tax all income if they consider the taxpayer a resident, others allow the foreign exclusion to the extent the fed does and still others will allow the taxpayer to be a temporary “nonresident” while overseas and then let him/her resume residency when he/she returns. My book has a chapter that discusses the various approaches and explains how each state handles it. How can our readers contact you if they have further questions? If any of the readers would like more information or have any further questions, I can be reached at: janebruno@bellsouth.net Lessons Learned: "Doc, am I going to die?"
Note from the Managing Editor: The significance of this case is that this is a likely scenario for many of us. Given the areas of the world we work, this could easily be you acting as the medical advocate for a fellow team/unit member. -JH Submitted by LTC Shean E. Phelps, MD "Doc, am I going to die?" . . . A case of sudden onset chest pain in a previously healthy 36-year old SOF warrior. This is a case of sudden, incapacitating chest pain and absent radial pulse in a previously healthy 36-year-old Special Forces Engineering NCO. This NCO had fallen onto and dislocated his left shoulder approximately one week prior. His unit had been conducting cold weather training for an upcoming special mission to a high altitude location. Early on the morning of his episode, he was preparing to return to the unit’s home base with the logistics run, as he was unable to participate in the ongoing training due to his recent injury. As he was moving his gear from his quarters to a vehicle he began to feel light headed and nauseated with a sharp, stabbing pain in his chest, left shoulder and upper back. Upon returning to his room, he decided to lie down to catch his breath. A concerned teammate alerted the medical officer. The medical officer arrived within minutes and found the NCO lying calmly on his cot. He was pale, non-diaphoretic, taking slow, shallow breaths and clutching a clenched fist to his chest. He told the medical officer "Doc, I think I tore a muscle in my chest . . . it feels like someone threw a spear all the way through my back". A rapid evaluation of the patient's condition and vital signs revealed a patent airway with good air exchange (RR 10) and a weak, slow, thready pulse at the left radial artery. The responding medical officer quickly checked the right radial pulse, which was noted to be completely absent. Simultaneous, bilateral blood pressure readings revealed the following: left anticubitus (BP 80/30, HR 36), right anticubitus (B/P absent, HR absent). [note: the unit medical officer had recently, within one month, completed a full class II military free-fall physical examination on this individual. At that time the soldier had no significant medical issues no history of hypertension, injury, recent viral illnesses, and was completely free of apparent physical defects. A retrospective review of his medical record did not reveal any contributory factors to this event.] The patient was immediately placed on full non-rebreather O2 mask, instructed to stay motionless, and was transported to a nearby medical facility which was approximately 10 minutes away by field ambulance. Upon arrival, the medical officer relayed the patient’s presentation and condition to the receiving emergency room physician and requested that he undergo contrast CT with immediate air transport to a medical center with advanced surgical capability. The receiving physician was apparently taken aback by the appearance of the individuals who brought the patient to the emergency room; both were dressed in full winter assault ensemble. When asked by the receiving physician (through an interpreter) to explain his symptoms the patient expanded on his initial comment stating, "I think I pulled a muscle in my chest and back, I was moving heavy bags to a vehicle." The patient appeared to be somewhat improved but was still complaining of pain in his chest and upper back; he stated his chest pain was still there but being replaced by sharp pain that radiated from the center of his chest up through the right side of his neck. Vital signs were taken on the patients left arm revealing BP 96/60, HR 58, RR 12. The receiving medical officer did not take blood pressure measurements on the patient’s right arm despite a pointed request by the transferring physician. The ER physician, who spoke very little English, stated that he felt that the patient had a severe back sprain and therefore needed some muscle relaxants despite the unit medical officers suggestion of a much more serious differential diagnosis. When the emergency room physician left the room to attend to another patient, the unit medical officer borrowed another blood pressure machine and ran them simultaneously revealing to the ER nurse the following findings: left anticubitus (BP 90/56, HR 48), right anticubitus (B/P absent, HR absent). Upon seeing this, the ER nurse pushed the call button and asked the ER physician to return immediately. She cycled the two blood pressure monitors and showed the physician who upon seeing the results ordered an emergency contrast chest CT and asked the staff to contact the local life flight office for possible transfer. During movement to the radiology suite, the patient began to complain of an impending sense of doom, became somewhat disoriented and vomited all over the trousers of the unit medical officer. Care was taken to avoid aspiration and the patient remained conscious throughout the subsequent events. Contrast CT of the chest revealed what the unit medical officer had suspected from initial presentation, an ascending, dissecting aortic aneurysm (9cm, Stanford Type A proximal) involving the take off of the brachiocephalic artery. Upon hearing the diagnosis the patient asked the unit medical officer, "Doc, am I going to die?" to which the officer responded, "Hell no, besides, you don't have permission to die, not in this place". The patient was moved to the hospital ICU and placed on vasopressor agents (despite the objections of the unit medical officer) while awaiting transport to a surgical center via air ambulance. Approximately 10 minutes later, both the patient and the unit medical officer were airlifted to the host nations level I trauma center co-located with their university hospital where a cardiothoracic surgical team was on standby for emergency surgery (in flight the unit medical officer discontinued the vasopressor agent drip). The patient was placed in hypothermic stasis for cardiac bypass and underwent open-heart surgery within 1 1/2 hours of initial presentation. Surgery revealed a large, dissecting aortic aneurysm (Stanford Type A/Debakey II) measuring 9 cm diameter that involved the base of the aorta, the entire arch (to include all its branches) that was completely occluding the brachiocephalic artery with minimal extension into the right carotid artery, and partially occluding the right coronary artery. Additionally, the patient was noted to have a congenital bicuspid aortic valve. First Aid and Pre-Hospital Life Support: It is unlikely that a layperson will recognize this condition. Laypersons and trained medical personnel should immediately activate emergency services and call for help and arrange for immediate transport (via air ambulance if available) to advanced medical care. In remote areas, immediate air evacuation is IMPERATIVE, by MEDEVAC to an advanced medical facility if available. One should transport the patient immediately to a facility capable of emergency cardiac surgery. A trauma center is preferred as a community hospital without a full cardiothoracic surgical service will not be sufficient to care for a patient of this severity. Supportive care including pain and blood pressure control should be provided en route to the medical center if at all possible. Treat for shock by placing the patient in a modified Trendelenburg position and administering oxygen therapy. Despite chest pain, do not administer nitrates. Apply cardiac monitoring and establish intravenous access early. Titrate fluid to blood pressure, but DO NOT USE vasopressors. Record a diagnostic electrocardiogram to distinguish between aortic dissection and acute myocardial infarction. Do not administer thrombolytics. Analgesia should be accomplished with regard to the vasodilative effects of opioid analgesics such as morphine, fentanyl, and nalbuphine and should not be provided to a patient in decompensated shock. Treatment: The risk of death due to aortic dissection is highest in the first few hours after the dissection begins, and decreases afterwards. Because of this, the therapeutic strategies differ for treatment of an acute dissection compared to a chronic dissection. An acute dissection is one in which the individual presents within the first two weeks. If the individual has managed to survive this window period, his prognosis is improved. About 66% of all dissections present in the acute phase. In the case of an acute dissection, once diagnosis has been confirmed, the choice of treatment depends on the location of the dissection. For ascending aortic dissection, surgical management is superior to medical management. On the other hand, in the case of an uncomplicated distal aortic dissection (including abdominal aortic dissections), medical management is preferred over surgical treatment. At surgery, the patient underwent surgical resection of his dissected aorta. The bicuspid aortic valve was evaluated as operating normally without significant regurgitation and the aortic valve annulus was in good condition. As the valve appeared to be functioning normally it was therefore spared. The dissecting aortic segment was surgically excised and a two-part Dacron/Gortex aortic "graft" emplaced in a 12 hour surgical procedure. The patient was brought out of stasis and transitioned off of cardiac bypass. Spontaneous cardiac activity resumed and the graft was examined for function and leaks. The patient was taken to the Cardiothoracic Intensive Care unit for recovery but returned to surgery early the next morning to repair leaking anastamosis sites. After this second surgery, the patient recovered quickly and was extubated on post op day 2. The patient remained in the University hospital for nine days and was recovered to US medical control for follow up and rehabilitative therapy. He resumed limited physical activity two weeks later and took an Army APFT within three months of his surgery. Even though his unit retained him, a medical evaluation board found he was fit for continued service but unable to meet the requirements of his original MOS (18C) or his specialized field of military free-fall duties. He remains on active duty to this day and is currently undergoing MOS re-designation. He is on track to fully retire from active duty service with over 25 years in the US Army. You can read the remainder of Dr. Phelps lesson under "Additional Information" at the end of the newsletter. Additional information: Aortic DissectionReview of the structures of the aorta is critical to understanding the pathophysiology of aortic dissection. The aorta, as with all arteries, is made up of three layers; the tunica intima (aka: the "intima", in direct contact with the flow of blood, is made up mostly of endothelial cells); the tunica media (aka: the "media" or middle layer, is comprised of smooth muscle cells and elastic tissue); and the tunica adventitia (aka: the "adventitia", the outermost layer, is composed of connective tissue). In the case of aortic dissection, blood, under relatively high pressure penetrates the inner lining of the aorta (the "intima") and enters the "media". This high pressure causes sheer forces which separate the intima from the media, allowing more blood to enter. This sheering/tearing effect can propogate along the entire length of the aorta causing dissection downwards into the base of the aorta and heart (involving the coronary arteries and/or causing tamponade) or dissect upwards into the vital arteries supplying the brain and down towards the kidneys, or both. Typically, the initial intimal "tear" is within 100 mm of the aortic valve. The most devastating risk in aortic dissection is aortic rupture leading to massive blood loss and death. Classification systems: The DeBakey system, named after surgeon and aortic dissection sufferer Dr. Michael E. DeBakey, is an anatomical description of the aortic dissection. It categorizes the dissection based on where the original intimal tear is located and the extent of the dissection (localized to either the ascending aorta or descending aorta, or involves both the ascending and descending aorta. The Stanford classification system was derived at Stanford Medical school and is divided into 2 groups; A and B depending on whether the ascending aorta is involved. Pathophysiology: The initiating event in an aortic dissection is a tear in the intimal lining of the aorta. With high pressures in the aorta causing blood to enter between the intima and the media at the point of the tear, the force of the blood entering the media causes the tear to extend beyond its initial site. This intrusion may extend proximally (closer to the heart) or distally (away from the heart) or both. As blood under pressure travels through the intima/media plane it creates a "false lumen" (the true lumen being the normal course of blood through the aorta). This results in a flap of intimal tissue separating the false lumen from the true lumen and is known as the intimal flap. As blood flows down the false lumen, it may cause secondary tears in the intima. Through these secondary tears, the blood can re-enter the true lumen. The root cause of intimal tears are not fully understood, but, quite often it involves degeneration of the collagen and elastin matrix that make up the tunica media. This finding is known as cystic medial necrosis and is most commonly associated with the genetic traits of Marfan and Ehlers-Danlos syndrome. Most aortic dissections originate with an intimal tear in the ascending aorta (65%). Approximately 10% originate within the aortic arch and 20% just distal to the ligamentum arteriosum in the descending thoracic aorta. In appx 13% of aortic dissections, there is no evidence of an intimal tear and it thought that the inciting event is an intramural hematoma. These cases are extremely difficult to diagnose as there no direct connection between the true lumen and the false lumen and contrast aortography may not reveal the defect. If suspected, aortic dissection secondary to an intramural hematoma should be treated the same as one caused by an intimal tear. Causes: Aortic dissection is most closely associated with hypertension (72-80% of individuals who present with aortic dissection have a previous history of hypertension), connective tissue disorders, and chest trauma. Although rare, vasculitis has been associated with cases of aortic dissection. Aortic dissection occurs most frequently in individuals who are between 50 to 70 years old. The incidence is twice as high in males as in females (male-to-female ratio is 2:1) and fully half of dissections in females occur before age 40 (typically during the 3rd trimester of pregnancy or in the early postpartum period). Bicuspid aortic valve is a congenital condition that seems to be associated with dissections in the ascending aorta. Bicuspid aortic valve is found in 7-14% of individuals who have an aortic dissection. The risk of dissection in individuals with bicuspid aortic valve has not been associated with the degree of stenosis of the valve. Marfan syndrome is noted in 5-9% of individuals who suffer from aortic dissection. In this subset, there is an increased incidence in young individuals. Individuals with Marfan syndrome tend to have aneurysms of the aorta and are more prone to proximal dissections of the aorta. Turner syndrome also increases the risk of aortic dissection, by way of aortic root dilatation. As previously mentioned, chest trauma is associated with aortic dissection. Trauma related aortic dissection can be divided into two groups based on etiology: blunt chest trauma (commonly seen in car accidents) and iatrogenic. Iatrogenic causes include trauma during cardiac catheterization or due to an intra-aortic balloon pump. Appx 18% of individuals who present with an acute aortic dissection have a history of open heart surgery. Individuals who have undergone aortic valve replacement for aortic insufficiency are at particularly high risk. This is because aortic insufficiency causes increased blood flow in the ascending aorta which can cause dilatation and weakening of the walls of the ascending aorta. Signs and symptoms: Approximately 96% of individuals with aortic dissection present with sudden, severe chest pain, often times described as "tearing", "stabbing", or "sharp" in nature. About 17% of individuals will be able to feel the pain migrate as the dissection extends down the aorta and will be able to describe this to clinicians. Location of pain is often times associated with the anatomic location of the dissection itself. Anterior chest pain is usually associated with dissections involving the ascending aorta, while intrascapular pain is typically associated with descending aortic dissections. Pleuritic pain may suggest acute pericarditis due to hemorrhage into the pericardial sac, an ominous sign. While the pain from aortic dissection may be confused with the pain of a myocardial infarction (John Ritter, famous actor, was misdiagnosed with heart attack and died from aortic dissection), dissection is usually not associated with the other signs that suggest myocardial infarction, i.e.: heart failure, ECG changes, diaphoresis. Furthermore, in some relatively rare cases, those individuals who have chronic dissections may not present with pain at all. Relatively uncommon symptoms that may be seen in the setting of aortic dissection include congestive heart failure (7%), syncope (9%), cerebrovascular accident (3-6%), ischemic peripheral neuropathy, paraplegia, cardiac arrest, and sudden death. Syncopal episode associated with aortic dissection is typically associated with (appx 50%) with hemorrhage into the pericardium leading to pericardial tamponade. Devastating neurologic complications of aortic dissection occur when one or more of the arteries supplying portions of the central nervous system are involved in the dissection. Cerebrovascular accident (CVA) and paralysis occur commonly in these cases. Abdominal aortic dissections (DeBakey III/Stanford B Distal) may compromise the branches of the abdominal aorta and involve one or both of the renal arteries. This occurs in approximately 5-8% of cases, while mesenteric ischemia due to involvement of the mesenteric arteries occurs in 3-5%. Blood pressure changes: History of hypertension is a predisposing factor for aortic dissection. Although many patients with aortic dissection will reveal a history of hypertension, blood pressure readings can be quite variable at initial presentation. 36% of proximal aortic dissection will present with hypertension and 25% will present with hypotension. 70% of distal aortic dissections will present with hypertension while 4% will present with hypotension. Of note, severe hypotension at initial presentation is a grave prognostic indicator and is usually associated with pericardial tamponade, severe aortic insufficiency, or rupture of the aorta. It is critical to provide accurate, bilateral measurements of blood pressure throughout the evaluation period. Pseudohypotension (falsely low blood pressure measurement) may occur due to involvement of the brachiocephalic artery (supplying the right arm) or the left subclavian artery (supplying the left arm) and result in wide disparities between measurements as compared side to side. Myocardial infarction: As previously stated, aortic dissection can be easily misdiagnosed as myocardial infarction. Accompanying myocardial infarction occurs rarely (appx 1-2%) with aortic dissection. The etiology of the myocardial infarction is involvement of the intimal flap of coronary arteries in the dissection. The right coronary artery is more commonly involved than the left coronary artery. The dissecting flap progresses around and occludes the affected coronary artery diminishing blood flow to the supplied heart muscle. If the acute aortic dissection/myocardial infarction is incorrectly treated with thrombolytic therapy (which will exacerbate the dissection) mortality increases to over 70%, due mostly to hemorrhage into the pericardial sac causing pericardial tamponade. Because aortic dissection may present similar to a myocardial infarction, the care provider must be careful to make the proper diagnosis PRIOR to initiating treatment for myocardial infarction, since the treatment regimen for myocardial infarction can be lethal to an individual presenting with aortic dissection. Diagnosis: Proper diagnosis of aortic dissection is many times difficult to achieve due to varying signs and symptoms that depend on the initial intimal tear and the extent of the dissection. In the classical case of an individual presenting with chest pain radiating to the back a differential diagnosis should include: The diagnosis of aortic dissection cannot always be achieved by history and physical alone. Visualization of the intimal flap and false lumen of the dissection via contrast imaging and/or arteriography is preferable. Common tests used to diagnose aortic dissection include a CT scan of the chest with iodinated (ensure patient is not allergic to iodine and/or shellfish) contrast material and/or a trans-esophageal echocardiogram (TEE). Other tests not always available include aortogram or magnetic resonance angiogram (MRA) of the aorta. These tests are not always available at smaller facilities and require special training/equipment. Additionally, these tests do not have equal sensitivities and specificities in the diagnosis of aortic dissection. In general, the imaging technique chosen is based on the pre-test likelihood of the diagnosis, availability of the testing modality, patient stability, and the sensitivity and specificity of the test. Chest X-ray: Whereas widening of the mediastinum on an x-ray of the chest has moderate sensitivity (67%) in the setting of an ascending aortic dissection it has low specificity and can signal many other conditions that cause mediastinal widening on chest x-ray. This being said, any and all patients suspected to have aortic dissection (and/or myocardial infarction) should have emergent chest radiography performed. A rarely seen but significant radiological finding in the setting of dissection is the "calcium sign". This is a finding on chest x-ray that suggests aortic dissection that is heralded by a separation of the intimal calcification from the outer aortic soft tissue border by 10 mm, typically seen in older patients. Additionally, pleural effusions may be seen on chest x-ray in association with aortic dissection. Effusions are more commonly seen in descending aortic dissections and if seen, they are typically found in the left hemithorax. Other findings in the setting of dissection are obliteration of the aortic knob, depression of the left mainstem bronchus, loss of the paratracheal stripe, and tracheal deviation. About 12%-20% of individuals presenting with an aortic dissection have a "normal" chest x-ray. ECG: There are no specific electrocardiographic findings associated with aortic dissection. About 1/3 of the time, the ECG will show signs of left ventricular hypertrophy, which is due to the long-standing hypertension seen in these individuals. Another 1/3 of the time the ECG would be considered "normal". If the ECG suggests cardiac ischemia in the setting of aortic dissection, involvement of the coronary arteries should be suspected. Computed tomography angiography & MRI: Computed tomography angiography has a sensitivity of 96 - 100% and a specificity of 96 to 100%. Disadvantages include the need for iodinated contrast material and the inability to diagnose the site of the intimal tear as well as limited availability. MRI is the current gold standard test for the detection and assessment of aortic dissection, with a sensitivity of 98% and a specificity of 98%. The disadvantage of the MRI scan in the face of aortic dissection is that it has limited availability and is often located only in the larger hospitals, and the scan is relatively time consuming. Natural history: Although the stated risk of death in untreated aortic dissection is related here as: Surgical management: Indications for the surgical treatment of aortic dissection include an acute proximal aortic dissection and an acute distal aortic dissection with one or more complications. Complications include compromise of a vital organ, rupture or impending rupture of the aorta, retrograde dissection into the ascending aorta, and a history of Marfan's syndrome or Ehlers-Danlos Syndrome. The objective in the surgical management of aortic dissection is to resect (remove) the most severely damaged segments of the aorta, and to obliterate the entry of blood into the false lumen (both at the initial intimal tear and any secondary tears along the vessel). While excision of the intimal tear may be performed, it does not significantly change mortality. Some methods of repair are: A number of comorbid conditions increase the surgical risk of repair of an aortic dissection. These include:
Feedback:Hi Jon - NICE - I like the updates - and about time someone takes care of just medics. Do you have feedback for us? Contact us here. Jobs:Check out the new link at: Medics - try this link - https://www.gwotjobs.com/rss/medical_jobs.php
Classifieds:Do you have something you want to sell? Want to reach medics around the world? Contact us here. Editorial Staff:Editor-in-Chief: Jeffrey A. Lee, MD, MPH vighetrnews@vighter.com Managing Editor: Jon Holmes vighternews@vighter.com Format Editor: Bob Sherron vighternews@vighter.com
|
News you can usePass it onIf you know someone who may be interested in receiving this newsletter, you can easily forward up to five copies at once. SubscribeIf you have received this from a friend click here to sign up. |
|
|
|
|