Needle Chest Decompression
	Date: Wed, 27 Aug 1997 15:49:13 -0400 (EDT) From: [Bengunn909@aol.com] Question for the list: I have tried needle decompression of tension pneumothorax pre hospital with a large bore cannula and found it to be of limited value. I have heard of a technique used by the military in combat where an incision at the site of a chest tube insersion ie 5th intercostal mid axillary with a finger stuck in and removed will do a better job removing air and blood if a formal tube is not available as is sometimes the case in situations where docs are not available and a last ditch effort is made. This is then covered by a three sided dressing. In some cases this is done bilateraly. This is taught to combat medics and special forces I understand - would civilain paramedics not be able to use this technique? and does anyone on the list know of its efficacy? Comments welcome
	Date: Sat, 30 Aug 1997 11:29:04 -0400 (EDT) From: KMATTOX@aol.com I have looked carefully at the civilian literature from Germany, England, USA, etc. including the helicopter data. There is indeed a lot of emotion relating to the ability to perform a technical assault on a patient, including needle decompression in the field. I have found NO, I repeat NO data which was prospectively collected in a randomized fashion which justifies this dangerous practice. The are which is the MOST out of control and is reviewed by the trauma service the least is the procedures performed by helicopter personnel. I would strongly recommend that prehospital chest decompression by ANYONE by any method be eliminated until appropriate evidenced based data exists... k
	Date: Sat, 30 Aug 1997 17:45:57 -0400 (EDT) From: Andrew Thurgood [AThurg2464@aol.com] Having had "some" experience of military and civilian pre-hospital trauma, I can confidently say that to apply a "three sided tape" to a chest wound in a "non-clinical" environment is exremely difficult, if not near impossible. To achieve the seals along the edges of the occulsive dressing, requires some skin preparation and drying......both these endevours are time consuming! In the pre-hospital arena, time is not at a premium if we follow the current guidence and emphasis on the "platimun ten minutes". To complicate matters, patients tend to be quite aggitated and move around, as is the case if you've been shot or stabbed...sods law...this will translate into a "three sided" dressing becoming blocked or ripped off. Needless to say....the cause of the aggitation requires exploring through many loops of AcBC assessment......carried out under copious clouds of oxygen. The point of aggressive management of chest injuries in the military setting by non-medical personnel is misguided. In a forward field situation, "nature" will provide triage to those with chest injuries...anyone surviving "God's triage" will then encounter a combat medical technician or regimental medical assistant who will exposed the casualty to the basic management ABC's and nothing more. It is not until the unfortunate soldier has arrived at a RAP/dressing station, that chest drains et al, maybe be sited....enter the regimental medical officer. As for special forces.....no comment :) A paramedic carrying out an incision at the site of the chest tube insertion, then sticking his finger in and out, may have to explain himself to the recieving A&E team as he delivers an exsanguinated patient........"open the chest.....spill the contents on the floor...blood lost on the floor is blood lost forever!" Pre-hospital chest management needs go no further than AcBC and drive like hell to the nearest appropriate A&E department....the patient requires a surgeon, not another hole in his chest. Needle thoracocentesis does work in patient's that REALLY have a tension, a patient may survive long enough to reach A&E with a pnuemothorax, but the odds stack against the patient with a rapidly delevoping tension......if one large bore needle does not appear to work, then add another. As a side line, if there is a hole already present in the patient's chest, there is a wound sealing system on the market that provides a unidirectional conduit for escaping air from the damaged chest wall.....turning a sucking chest wound into a blowing only chest wound. It is called an "Asherman Chest Seal", distributed by Vernon-Carus Ltd, Penwoth Mills, Preston, Lancashire, England. PR1 9SN Andrew Thurgood Advanced Nurse Practitioner (A&E) UK
	Date: Sat, 30 Aug 1997 16:01:46 -0600 From: Cybercentro [plango@acnet.net] Needle decompresion is only a paliative measure meant to help you get the patient to the nearest treuma center. And going a little into physics, it's all you need to equal the intrathoracic preasure to athmospheric preasure. It's indicated is Tension Pneumothorax. About the finger through a stabwound , we have to see under what situation is the procedure indicated, they're in the battlefield and those guys are usually far behind enemy lines. This situation will hardly be the one you may have on any street, highway or rural area. I think it may work faster, but better? . Also there is the increased chance of letting in a infection. I don't think you'll be doing many of this, at least in peace time. Dr. Porfirio Lango Trauma Surgeon Hospital General de Mazatlan Mexico
	Date: Mon, 1 Sep 1997 11:01:43 +1000 From: Mark C Fitzgerald [markfitzgerald@harveynorman.com.au] It often depends on the underlying cause for the tension. If it is secondary to positive pressure ventilation in association with pulmonary injury needle decompression may be of variable efficacy. You can insert a 'Minitrach' cricothyroidotomy 4.5 mm tube with Heimlich valve attached through the 5th ICS after cutting down using the scalpel that comes with the set. Alternatively, the new Chest Drainage sets from Portex are effective (although both lack an auto-transfusion capability). I usually infiltrate first with a Lignocaine Mini-jet.
	Date: Mon, 1 Sep 1997 12:54:20 -0500 (CDT) From: John A. Aucar, M.D. [jaucar@bcm.tmc.edu] Why was needle decompression limited? Air should release rather easily. Blood will generally not cause tension, and if it does, releasing it in the field will not accomplish anything except making a big mess. I don't have a problem with making a hole and putting a finger in if you don't have any kind of tube, but if you do it both sides you better put the victim on positive pressure ventilation or have way to suck the lung back up to the chest wall. Bilateral pnuemothoraces are not well tolerated and I don't have tremendous faith in three sided dressings. JAA
	Date: Tue, 2 Sep 1997 18:05:57 +1000 From: A K Bacon [bacona@zen.ocean.com.au] Melbourne ambulance (again) has been decompressing tension pneumothoraces under protocol for ten years. We use a special decompression set from COOK medical. It works, we have good saves. The Tension PN is diagnosed on clinical grounds (BP down, venous distension in neck, widened ribs spaces on affected side, etc) or if not glaringly obvious we insert a 23 g needle attached to a 20 ml syringe wit a few mls of saline. Walk off the top of the thrid or fourth rib in the MCL and then aspirate. Little bubbles = no snug fit with needle, or in lung, big bubbles = PN. Proceed to decompression. DR A K Bacon Medical Director Metropolitan Ambulance Service
	Date: Tue, 2 Sep 1997 09:51:20 -0400 From: darren walter [DPW999@compuserve.com] Needle decompression may buy time in a critical situation, but can you be sure it is long enough or that it doesn't block or kink? Is it adequate? HEMS-London (Helicopter Emergency Medical Service) use the technique of THORACOSTOMY in the field relatively frequently. We would aim for the fourth space in the anterior axillary line, behind the breast tissue (if present). The insertion of a finger ensures that a proper decompression is achieved. Works like a charm. Often patients with this level of trauma will be intubated and positive pressure ventilated. If so, we leave the thoracostomy open without a tube. If there is sufficient trauma to one side, can you be sure that a problem will not arise on the other side in transit? My personal experience is that "if you think about it, you should do it". When I have shied away I have regretted it. My procedures are usually done in pairs in the pre-hospital environment! A formal chest tube is inserted in the A+E Department early in the resuscitation, after soaking the wound in iodine solution. Later infection has not been identified as a problem. Occasionally the thoracostomy can be sealed by immobilising the arms at the side of the chest, particularly if the hole is made with the arm at 90 degrees abduction. Forewarned is forearmed, watch the airway pressures and check the patency if ventilation is becoming more difficult. A formal chest tube insertion might be indicated here, but increases your pre-hospital time. I would never consider leaving a thoracostomy open in a spontaneously ventilating patient during transfer. A large pneumothorax would be very distressing. A chest tube with an open urinary catheter bag allows air to vent, and seals the iatrogenic sucking chest wound. Certainly in the UK some Ambulance Services allow the use of needle decompression. For thoracostomy, I would have reservations about the decision process (not physician controlled) and skill level for what would be a very rare procedure for each paramedic. Ventilated trauma patients can be maintained with needle decompressions for the relatively short running times to a UK hospital without risking inappropriate use or complications. The use of pre-hospital doctors or more advanced trained paramedics (the suggested paramedic practitioners) as a back up response would allow these sort of interventions to be carried out in the field. This then raises the question of "if we can, should we"? Best wishes Darren Walter
	Date: Fri, 5 Sep 1997 19:56:09 +0100 From: Dr. Ed Walker [Ed_trauma@limeland.demon.co.uk] I'm often easily confused, but never more so than by this. Apart from anything else, the whole point of needle decompression is that it is virtually impossible to do any lasting harm (if inserted correctly), and is a very quick way of saving someone's life.
	Date: Fri, 5 Sep 1997 18:57:53 -0400 (EDT) From: Ken Mattox [KMATTOX@aol.com] One MUST loudly shout from the earth top that there is strong evidence that random and unsupervised chest decompression is DANGEROUS. I can point ot numerous iatrogenic injuries, many of them fatal which have been inflicted by aggressive well meaning prehospital providers and Emergency room persons, such as puncture of the heart, puncture of the lung, air embolism, puncture of the diaphragm, liver, spleen, colon, etc, all prior to any good evaluations and prior to surgical evaluation. Much of the protocols which cause these injuries are totally outside the hospital's and the trauma services quality management programs. I recall a case in the distant past of reviewing a chart of a fatal cardiac puncture from a pericardiocentesis needle thrust into the heart by a well meaning flight nurse, acting by practice guidelines, under protocol, developed by the EMS committee of the flight program, and premission retrospectively granted by signature of an emergency room physician. When reviewed and condemned by the trauma committee the surgeon became the focus of an attack as to why he/she should question the flight program and its (absent) by protocol medical director. This story can be repeated many times for EMS personnel in ground ambulances. We often "see but we do not observe" as was so stated by Sherlock Holmes to Dr. Watson (Can anyone tell me in which book this was cited?). It is my STRONG opinion that ALL prehospital chest and pericardial decompressions in urban, helicopter, and EMS practice be immediately put on HOLD until evidenced based outcomes comparative data is presented. The burden of proof on producing such good information rests with those who would recommend this DANGEROUS practice. If any of us do not admit that this practice is dangerous, then we just have not been examining our own data at our own institutions close enough.
	Date: Wed, 5 Jun 1996 17:47:47 +0100 From: Simon Carley [s.carley@btinternet.com] Whilst I totally agree with K's (Ken Mattox???) statement that practice should be based upon properly conducted research. (I am a boring exponent of such practice) let us not forget that "abscence of evidence is not evidence of an abscence of effect". Is there any evidence (from prospective RCT's) to suggest that it is dangerous - still the answer is no. You are then left with the situation of "no evidence" but a consensus of opinion in favour of the procedure (*I think most people would decompress a tension pneumo). Leaves you in a difficult clinical and legal situation if you choose to stop people from doing it. What you are saying is that we don't know what the true answer is. Right answer???? Who knows, but early decompression makes clinical sense to me. BUT Making the diagnosis is the real issue. Simon Carley Clinical Fellow in Emergency Medicine Department of Emergency Medicine Manchester Royal Infirmary
	Date: Sat, 6 Sep 1997 12:14:51 +0300 (IDT) From: Avi Roy Shapira No doubt true indications for needle chest decompression are rare indeed. This is why it is a bit of a demagoguery to call for prospective random allocation data. You know full well, Ken, that such data can never be aquired, and is not necessary either. One does not need an RCT to prove that an Rx is helpful, if the condition it treats is lethal enough. (suppose a condition is 100% fatal,you give iv Rhubabitocitin and one patient recovers. That is good enough evidence that Rhubabitocitin is effective) Now let me ask you just this: You see a trauma victim in the field, pulseless, prominent neck veins, the trachea is deviated to the right, no breath sounds on the left. You have a large needle in your hand, and you are a dermatologist, who happened to walk by. You know where the 2nd interspace is, but you never put in a chest tube. Do you or don't you stick the needle? Avi
	Date: Sat, 06 Sep 1997 11:23:42 -0700 From: Gail Waldby MD [gwaldby@basec.net] Better yet, you are Ken Mattox in the same situation, do you stick the needle in or not? Or another trauma or general surgeon, do you stick in the needle or not? I suspect the answer is yes, although, I personally do not carry needles or trach sets etc. around with me. Gail Waldby, MD Huron Clinic SD
	Date: Sat, 6 Sep 1997 09:14:12 -0400 (EDT) From: Davy Gunn [DavyGunn@aol.com] Some good stuff on this subject coming through. I would like a clear answer to this question as it bugs me. The HEMS guys make a hole and say it works. Others suggest this is highly dangerous. Well forgive me being a little pedantic but its ok to let them die if you don't ? I have performed 2 decompressions using the needle method with only one being partially successfull but it got the guy to the surgeon who then did the buisness - which is what were all about. The other guy died in front of me becasue the cannuala would not reach through the big layer of fat covering him and clogged with it. Just maybe this technique of making a hole would have worked, who knows. The question is does the guy with the scalpel really have good clinical judgement? As a paramedic I would admit that most of us (paramedics) would not. And will hapilly admit that it scares the crap out of me. Personaly though if confronted with the scenario again where my casualty died on me because I could not release the tension, I would go for it and take my head in my hands if others wanted to put it there. I dont know of anyone who sees a lot of trauma work who does'nt agonise over past patients, and contemplate future ones. Maybe what we need is a good look at some of the skills as suggested by Simon Carley, and see if they really are effective. Its easy (well not that easy!) to demonstrate them in well lit A/E depts but on a cold wet windy night at the roadside or up a mountain with a trapped patient the book gets written as you go. Maybe this all needs looking at?
	Date: Sat, 6 Sep 1997 11:57:38 -0700 (PDT) From: Thomas J. McGuire [TMcGuire@LanMinds.com] The issue of chest wall thickness (1) caused me to poke around and see what length catheters were in our decompression kits. Tom (1) Title: Needle thoracocentesis in tension pneumothorax: insufficient cannula length and potential failure. Date of Pub: 1996 Jun Author: Britten S; Palmer SH; Snow TM; Issue/Part/Supplement: 5 Volume Issue: 27 Pagination: 321-2 Journal Title Code: GON Publication Type: JOURNAL ARTICLE Unique Identifier: 96287834 ISSN: 0020-1383 Abstract: Advanced Trauma Life Support guidelines recommend the use of a cannula 3 to 6 cm long to perform needle thoracocentesis for life-threatening tension pneumothorax. The chest wall thickness in the 2nd intercostal space, mid-clavicular line, was determined by ultrasound in 54 patients aged 18 to 55 years, and ranged from 1.3 to 5.2 cm (mean 3.2 cm). In thirty-one patients (57 per cent) the chest-wall thickness (CWT) was greater than 3 cm, the minimum recommended cannula length, although in only two (4 per cent) was it greater than 4.5 cm, the length of cannula commonly used in the UK. As a 3 cm cannula would fail to reach the pleural cavity in over half of patients, we suggest that the recommended shortest length be increased to 4.5 cm. Unsuccessful needle thoracocentesis using a 4.5 cm cannula should be followed immediately by insertion of a longer cannula or a definitive chest drain.
	Date: Sun, 07 Sep 1997 21:21:31 +0900 From: Steven Wright [stevenwr@adelaide.on.net] No! You ask the more than experienced and tight spincter muscled paramedic to do it for you.> That way they wear the grief and (I hope) place it in the right spot. Steve. BTW I have not placed one and dread the day I do! Steve Wright. Paramedic. South Australian Ambulance Service. Adelaide. Australia.
	Date: Sat, 6 Sep 1997 04:47:25 -0400 (EDT) From: Ken Mattox [KMATTOX@aol.com] In all due respect those who have protocols and have "saves" until one randomizes patients into groups, their impressions are often FAULTED. Witness the views about the earth being flat, the sun revolving around the earth, the fallacy of MAST, aggressive fluid resuscitation, and several other time honored "protocols." NO where has there been more emotion and less science than in the prehospital treatment of trauma. No, I do not "stick in needles" in the field, nor would I. I furthermore, do not "stick in needles in the emergency center. In opposition to others on this board who either have not recognized, or not reported their complications, I have seen complications, including fatal systemic air embolism from a mere, simple, well meaningly benign "sticking of a needle" into the pleural cavity. If there is a requirement for a post taumatic pneumothorax, I put in a LATERAL chest tube of sufficient size to do the job.
	Date: Mon, 8 Sep 1997 14:02:08 -0700 (PDT) From: Thomas J. McGuire [TMcGuire@lanminds.com] The September 1997, Annals Emerg Med, p. 395 has a Research Forum abstract re prehospital needle thoracostomy. The brief abstract reports a prospective study of 6,241 trauma pts, 114 NTs performed on 108 pts. Mortality rate 28%. 5 pts showed field vital sign improvement; 7 pts had subjective improvement breathing; 2 NTs didn't penetrate soft tissue; 7 pts got NT without apparent chest injuries (two iatrogenic pnxs). No other complications. Guess you'll have to attend the ACEP conference in SF to get the rest of the story. By M. Eckstein, USC School of Medicine. Tom
	Date: Tue, 9 Sep 1997 17:38:52 +0300 (IDT) From: Avi Roy Shapira [avir@bgumail.bgu.ac.il] I agree that there is no place for needles in the EC, nor did I ever put one in myself. I always put lateral chest tubes, even before I became your pupil. However, I can see use for them in certain rare situations, where there is no risk. A person who is dying from tension pneumothorax may benefit from the needle, if that is all that is available. He would not be any deader from the potential complication. Wouldn't he? Having had the privilge of working under your guidance for a year, it is clear to me that what you are preaching against is indiscriminate needling when other, better and safer means are available. Condemning needle application altogther is dangerous and carries the argument a bit too far. Avi
	Date: Mon, 8 Sep 1997 09:34:17 -0400 (EDT) From: Gordon Doig [gdoig@biostats.uwo.ca] > No doubt true indications for needle chest decompression are rare indeed. > This is why it is a bit of a demagoguery to call for prospective random > allocation data. You know full well, Ken, that such data can never be > aquired, and is not necessary either. One does not need an RCT to prove > that an Rx is helpful, if the condition it treats is lethal enough. > > (suppose a condition is 100% fatal,you give iv Rhubabitocitin and one > patient recovers. That is good enough evidence that Rhubabitocitin is > effective) 100% lethal conditions are rare (I can only think of about 5). So, what is 'lethal enough'? A septic patient with ARDS has an 80% chance of mortality. How many septic ARDS pts do I need to treat to prove my new therapy is effective? > Now let me ask you just this: You see a trauma victim in the field, > pulseless, prominent neck veins, the trachea is deviated to the right, no > breath sounds on the left. You have a large needle in your hand, and you > are a dermatologist, who happened to walk by. You know where the 2nd > interspace is, but you never put in a chest tube. Do you or don't you > stick the needle? Thats an intersting scenario Avi, but I don't think we were discussing if dermatologists would make good first responders.... but maybe we should ask the dermatologists on this list. We were discussing what should be done in the face of a lack of evidence.... Gord
	Date: Tue, 9 Sep 1997 18:31:20 +0300 (IDT) From: Avi Roy Shapira [avir@bgumail.bgu.ac.il] > 100% lethal conditions are rare (I can only think of about 5). So, what is > 'lethal enough'? A septic patient with ARDS has an 80% chance > of mortality. How many septic ARDS pts do I need to treat to > prove my new therapy is effective? In theory not too many. Supposed I find a cure for ARDS. I treat 10 and they all survive, I treat another 10 and again they all survive. Would you find a committee that will approve an RCT? Now new therapies for ARDS never have this kind of effect, and ARDS is itself a poorly defined condition. (What if the PO2/FiO2 ratio is 201 and not 199? is it ARDS or acute lung injury?) So you need an RCT. Tension pneumothorax is 100% fatal if untreated, and is well defined. So the question here is not whether chest tube is better than needle application. We agree that it is not, if only for the simple reason that any successful needle application will also get a tube. The question is whether needle application is better or worse than no treatment. We often agree not to accept no treatment. I don't rememer any RCT of early breast cancer that had a no treatment arm, and I don't recall any RCT on the utility of lateral chest tubes. I have seen lethal complications from incompetently placed chest tubes, probably more than from incompetently placed needles. Should we bar chest tubes too? I also have not seen any RCT on the utility of ventilation of patients with ARDS (vs curbing their respiratory distress with morphine for instance) and you know as well as I that positive pressure ventilation is a risky business. So perhaps we should not ventilate patients with ARDS? After all, 80% will die anyway, as you say, and surely some will survive without positive pressure ventilation. You and I take many things for granted. We can't help it. It is good that someone questions any of these, and having hard data is better than common sense. But when there is no data, all we have left is common sense. We should not discard it down the wind just because it is not fully backed with hard numbers. Avi
	Date: Mon, 11 Aug 1997 18:46:24 +0100 From: Simon Carley [s.carley@btinternet.com] If we stopped doing everything in prehospital care/ resuscitation for which there was no level 1 or 2 evidence for would it be worth going to work tomorrow? *systematic review, metaanalysis or large PRCT - as per Cochrane Has anyone ever done an RCT of oxygen therapy in trauma??????? :-) I'm probably going to leave this thread now as I think we generally agree on principles, perhaps I'm just getting a little pedantic about your insistence on only using high level evidence in a field where there is not a lot of it about. Interesting discussion, thanks for your time. Simon Carley Clinical Fellow in Emergency Medicine Department of Emergency Medicine Manchester Royal Infirmary
	Date: Tue, 9 Sep 1997 18:43:34 +1000 From: A K Bacon [bacona@zen.ocean.com.au] Someone asked about the time honoured tradition of administering oxygen in trauma. Why do we do it? The answer goes back to at least April 1964, a classic article produced by J F Nunn and J Freeman from London. The reference is Anaesthesia, April 1964 Vol 19 No 2, pages 206 to 216. This was helpfully reproduced in Anaesthesia 1995 Vol 50, pages 794 - 800. In brief they found that there was an increase of up to 78% in physiological dead space relative to tidal volume in haemorrhage. The commentary includes the following gems of history and philosophy: 1. A paper on the effects of haemorrhage in 1943 had recorded all sorts of data which had merely been a mystery at the time. 2. Accurately record data even if it doesn't make sense when you are doing it.
	Date: Tue, 9 Sep 1997 12:59:49 -0400 (EDT) From: [MikelMD@aol.com] Hi -- An interesting thought and one which probably hasn't been considered by too many. Ken (or anyone else out there) -- is there some already published data on this I could review to have more basis for an opinion? Are there studies underway or a way to formalize retrospective information? Though all you've written makes great sense, I don't have enough information to have an opinion -- thanks in advance for the help. Take care. Mikel :-) Mikel A. Rothenberg, M.D. Emergency Care Educator Medicolegal Consultant North Olmsted, Ohio USA Professor of Emergency Medical Services American College of Prehospital Medicine
	Date: Wed, 10 Sep 1997 17:45:44 -0400 (EDT) From: Ken Mattox [KMATTOX@aol.com] Yes, a great deal has been written. In regards to helicopter operations, the latest article is in last months J Trauma from Hermann Hospital in Houston. Innumerable articles have been written on systemic air embolism. The variances in approach to EMS in the nursing, air ambulance, EMS, emergency medicine, and trauma literature, and the varing and even similiar outcomes bespeak to the point that the biased views derived from anadotal observations are also variable. We tend to remember our most recent good or bad outcome. Looking objectively, I can find NO data (other than anadotal testimonials) to support prehospital pleural decompression by ANYONE, flight nurse, physician, paramedic, etc. I also can find NO outcomes data that sending a physician to the scene of an accident, via car, truck, bike, ambulance, helicopter, or concord has resulted in ANY change in those who die of their wounds. The newly published Military Medicine Textbook from USUHS and edited by Col Ron Belimy clearly demonstrates that the percentages of those who DIE of wounds is unchanged in ALL of our wars since the Crimean. Let us not be diluted and blinded by our desire to be technical and create new expense and dynasties, based only on anadotal data. I still contend that I have seen more problems with blind pleural and pericardial decompression than I have seen saves. Currently, I have been directly or indirectly involved in the evaluation and treatment of more than 200,000 trauma patients over last 35 years. Many of these were on some specific research protocol and for whom we have prospective data. If we are not professional enough to study what we "think" is appropriate on an emotional basis, we should enter another field as we already are extinct.
	Date: Thu, 11 Sep 1997 08:53:45 +0000 From: Jerry Eckert [jerry.eckert@usspg.eds.com] > The newly published Military Medicine Textbook from USUHS and edited > by Col Ron Belimy clearly demonstrates that the percentages of those > who DIE of wounds is unchanged in ALL of our wars since the Crimean. An interesting statistic; however, it may be somewhat deceptive. Weapons technology has changed tremendously since the Crimean war. It could be argued that, with all other factors being equal, the mortality rate should have increased as weapons became more lethal. Also, we need to remember that mortality is not the only outcome of interest in the evaluation of treatment for life-threatening conditions - traumatic or medical. For those patients who do survive factors such as residual impairment, duration treatment, and quality of life are the metrics of interest and are just as important (perhaps even more so to some) than simply whether the person survived. - Jerry