Ignored Aspects of Two Techniques in Accident Management
(non-pneumatic MAST and vacuum mattress)
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To my biggest frustrations as an emergency physician can be counted a mission where I spoke to a traumatised patient, then anaesthetised and intubated him while waiting for the helicopter and later learned that he had died shortly after the admission due to abdominal bleeding, a diagnosis suspected already on the emergency site. This event gave rise first to an investigation over the size of the problem [1]:

Died in accident (police statistic)         430
Mission protocol                                   239     100 %:

Died prehospitally without CPR            94      39 %
Died on site after CPR                           43      18 %
Died in hospital after CPR on site          11        5 %
Died in hospital w/out prehosp. CPR     91       38 %      100 %
Haemorrhagic shock                              49                       54 %
Responsive after accident                      25                        27 %

Table 1: Traffic accident fatalities in Lörrach County 1980-1996.

We examined the patients with a fatal accident according to a list made by the traffic police of Lörrach County during 17 years [Table 1]. The first reduction was necessitated through the absense of protocols in 191 cases, leaving 239 for further consideration. If only the patients are considered without prehospital cardiac arrest, then 54% of these were in a haemorrhagic shock and 27 % were not unconscious. For greater details, but therefore accepting a smaller number of cases, I studied the 60 fatalities from this list where I had been involved [Table 2].

60 fatalities registered (1982-96), of them:
     30  dead on site
       3  seen only for secondary transfer
     27  died after admission, of them:
          13 awake after accident, of them:
               2 thoracic bleeding *
               7 intra-abdominal bleeding *
               1 3° burns, 95%
               2 postoperative complications §
               1 delayed ARDS after thoracic trauma §
          14 comatose after accident, of them
              3 intra-abdominal bleeding *
              1 old-age multitrauma (not intubated) *
             2 head trauma with CPR on site *
             4 isolated head trauma
             2 other multitrauma

Table 2: Analysis of 60 traffic accident fatalities of a the author. * Death within 4 hr after admission;
 § 3 patients intubated > 48 hr after admission

In three cases, I saw the patients only for secondary transfer and in another 30 cases, the patients were pronounced dead outside the hospital, with or without a brief CPR. Among the remaining 27 patients, abdominal haemorrhage was the cause of death in 10 patients and thoracic bleeding in another two. Distinguishing between primary comatose and responsive fatalities, roughly half of the latter died from abdominal bleeding.
In conclusion of this study, performed in an area of advanced and aggressive prehospital emergency medicine, haemorrhage now evolves as the predominant cause of death among primarily responsive accident survivors. The next question was, if there was anything to do against it. At this time it must be understood that if such a measure is found, such a cause of death shall be considered preventable henceforth for the cases where the method was not applied.

Fig. 1: Compression (patency protection pending) Fig. 2: Momburg's compression

It is an old and often repeated observation, that it is possible to halt external (visible) bleeding through compression. This claim is certainly not subject to any controlled studies, such a study would violate basic ethics. In the meantime widely forgotten, compression has also been used against internal bleeding sources, both in the 19th and the first part of the 20th century. Many principles and devices have been constructed for this purpose, among them the compression the the lumbar aorta in cases of postpartal atonic bleeding, described by J. Momburg (1870-1939). From a logical point of view, these were the predecessors to the pneumatic antishock-garment [PASG] described 1904 by Crile [2]. From the desire to apply abdominal compression, we therefore instituted a non-pneumatic version of Medical Antishock Garment [MAST] in our rendez-vous ambulance in 1996.

Fig.s 3 & 4: Some older devices for abdominal compression, by courtesy of Prof. Jörg Waninger (with Fig. 1)

For incidental reasons, our first uses of MAST did not concern traffic accidents. Among them, two patients with aortic bleeding and pre-final haemorrhagic shock received it, with restoration of their circulation (in one case even need for antihypertensive therapy by the short-acting betablocker esmolol) and subsequent transfer to successful operation in Basle [3]. A review identified four other case-reports with identical conclusion [4-7]. If compression can act upon this disease with an only secondary effect upon the shock, we believe it must also be useful for venous and organ bleeding.

This was not supported by another review of MAST/PASG [1]. However, it was soon clear that not the impact upon bleeding, but that upon shock was the issue studied, according to the name of these devices which includes the concept of “Antishock.” In particular, the two randomized studies [8,9] do include many patients with thoracic bleeding. In a previous review, McSwain [10] found thoracic trauma to be a counter-indication to PASG. From a logical point of view, it must be considered wrong – not just a waste of timne –to increase the blood pressure in e.g. thoracic bleeding if you are incapable of acting against blood loss simultaneously. Moreover, the exclusive American studies did not utilize physicians on site and hardly intubated the patients in advance of applying MAST, making this measure much more dangerous later on.

MAST is very painful in the presence of abdominal bleeding, and just for that reason, we soon set anaesthesia as a precondition, only permitting others to start compression of the legs while we were securing the airways. These patients generally do not anticipate the emergency and have a full stomach, thus increasing the risks of aspiration if intubation is carried out only after applying abdominal pressure. Unfortunately, anaesthesia and intubation also pose risks of adverse effects [11], a risk to be balanced with the expected advantage of halting bleeding.

At this point, it is necessary to stop and reconsider the message delivered here. I am uncapable of delivering figures showing that external abdominal compression (e.g., originating in MAST) may reduce fatal abdominal bleeding. This issue has not been studied by anyone. The use of logical arguments is not in favour nowadays where randomised controlled trials [RCT] and evidence-based medicine [EBM] decides about the opinions. In order to strengthen my arguments, but therefore losing sympathy with the majority of physicians devoting themselves to this principle, it turns necessary to fight back in making aware of some weaknesses in EBM [Table 3]. Considering the first nihilistic effect of EBM, it seems that MAST lost credit in American studies because it was used wrongly, in wrong patients and under the wrong assumption. Rarely were these patients intubated in advance, they often had counterindications for MAST and the option was ”Antishock,” not to stop bleeding. In consequence, MAST is losing sympathy. Was it perhaps once used too often (and wrongly) and now too seldom?

1st nihilistic effect of EBM:   If you use a method wrongly,
                                                  an RCT will probably show
                                                  that it does not improve therapy.
2nd nihilistic effect of EBM: What cannot be studied by RCT is always
                                                  claimed negative and speculative.
3rd nihilistic effect of EBM:  Guidelines necessarily refer to old principles.
                                                  New principles  are therefore always in contrast
                                                  to existing guidelines;  in turn, they are not studied.

Table 3: Nihilistic effects of Evidence-Based Medicine [EBM] (EBM is a man-made construct, in which thevidence of a clinical issue is weigthed, giving preference to RCT and meta-analyses of the same).

 Should you believe in the possibility also to minimize internal abdominal bleeding through compression, the exact limits to the therapy remains open to further study. It seems possible to minimize bleeding from pelvic fracture as well as that caused by spleen and liver rupture, obstetric bleeding and even aortic aneurysm. Other sources (e.g., gastric bleeding) must currently be considered purely speculative targets.

Fig. 5: CT of author with non-pneumatic MAST (invisible - visible is my belt, which I forgot to take off).

We have decided to utilize the non-pneumatic version of MAST. It was effective in meanwhile three cases of prefinal aortic aneurysm and poses other advantages, among them the capability to perform computed tomography by X-ray or even magnetic resonance (absense of metal parts). Another advantage, of importance for air-rescue, consists of the stabile compression independant of flight heigths and the absence of manometers to steal the doctor’s attention.

I wanted to create a new principle, combining this device with the vacuum mattress [VM], but then we noticed other problems with that device. And suddenly, the spine board [SB] entered our peaceful sphere.

With any fracture, also spinal ones, immobilisation must be considered to decrease nervous damage. If the uncomfortable strapped patients on the spine-board can be considered immobilized, is a question of its own, but that is what ATLS recommends. Due to the risk of tissue necrosis, its use is restricted to two hours, which certainly does not cover both the prehospital and diagnostic in-hospital phase until operation. Worse, the Cochrane register recommends controlled, placebo based studies, which I at least consider roughly unethical.

Fig. 6: Artifacts disturbing radiological examination

At least, it is true that the vacuum mattress may produce very disturbing artifacts, and that was the target of our first study [12]. From that, you can at least see that there is a big difference in this production of artifacts.

Fig. 7: Shrinkage of 6 different VMs, only tolerable in one. By courtesy of Dr. Winfried Reichert.

Much worse is another phenomenon, which we have only started to study. These data have not yet been published. You can see that only one of the mattrasses studied reaches the demand set by the European Norm. The others do more or less cause a compression upon the spine when air is evacuated.

It is therefore possible to improve the vacuum mattresses themselves and, to my mind, this is the only suitable way of stabilizing patients suspected of spinal injury. It is also required to improve the European Norm, which is today acting against the use of this rescue device in the diagnostic phase. I could not offer you much help against any use of the spine board, which is protected by strong dogmatic forces, but you can test its effects yourself in lying down on the floor at home – 10 minutes should suffice, if there is no carpet.


 1. Schou J, Ginz HF, Herion H-P, Huck D, Blum R, Fehlmann R, Ummenhofer W. Abdominal haemorrhage – a preventable  cause of death after field stabilization? Resuscitation 2000;43:185-93.
 2. Crile GW. The resuscitation of the apparently dead and a demonstration of the pneumatic rubber suit as a means of controlling the blood pressure. Trans So Surg Gynecol Assoc 1904;16:361-70.
 3.  Schou J, Hauser E, Schreiner W. Use of non-pneumatic antishock garments for ruptured abdominal aortic aneurysm. Eur J Emerg Med 1997;4:169-71.
 4.  Burn N, Lewis DG, McKenzie A. The G-Suit: Its use in emergency surgery for ruptured abdominal aortic aneurysm. Anaesthesia 1972;27:423-7.
 5.  Walsh K. Ruptured abdominal aortic aneurysms. Amer Fam Phys 1981;24:26-9.
 6.  Gustavson RA, McDowell DE, Savrin RA. The use of the MAST suit in ruptured abdominal aortic aneurysms. Am Surg 1983;49:454-9.
 7.  Dietze T, Uhlig HE, Kretschmer D, Hirt R. Antishockhose: Lebensrettende Sofortmassnahme bei einem rupturierten abdominellen Aortenaneurysma. Notfallmedizin 1989;15:457-60.
 8. Mattox KL, Bickell W, Pepe PE, Burch J, Feliciano D. Prospective MAST-study in 911 patients.. J Trauma 1989 29:1104-12.
 9. Chang FC, Harrison PB, Beech RR, Helmer SD. PASG: does it help in the management of traumatic shock? J Trauma 1995;39:453-6.
10  McSwain NE. Pneumatic anti-shock garments: state of the art 1988 Ann Emerg Med 1988;17:506-25.
11. Schou J. Three techniques for prehospital emergency anaesthesia. JEUR 1994;3:139-45.
12. Schou J, Kiermayer H, Ummenhofer W, Herion H-P. In Search of the Most Suitable Technique for Truncal Spinal Immobilization with Associated Radiography. Eur J Emerg Med 2001;8:89-92.

Preliminary version, July 9, 2002,
after lecture at TraumaCare, May 23-25, Stavanger, Norway.

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