ANALYSIS OF CAUSES OF DEATH IN A SAMPLE OF PATIENTS WITH POLYTRAUMA IN MOSCOW Korobushkin G.V., Shigeev S.V., Zhukov A.I.
Priorov National Medical Research Center of Traumatology and Orthopedics, Moscow, Russia
According to results of global investigation of causes of mortality in the whole word, 5.8 million persons die from injuries each year. It is 32 % higher compared to HIV, malaria and tuberculosis together [1, 2]. According to WHO, road traffic accidents take the ninth cause of death in the whole world, and is the main cause among people at the age of 15-29 [3]. As result, a question appears. Are there any cases of injuries when death can be prevented? Which factors influence on it?
Specialists from various countries, including USA, Australia, Japan, European countries, deal with these issues [4]. However, there are few Russian studies of this problem. One of the recent review articles by Roman Pfeier (2019) does not mention any sources from Russia [4].
According to the data from Rosstat, about 139 thousand people died from injuries and other external causes in 2017. The proportion of road traffic accidents included 19,885 deaths [5]. For reduction of mortality from injuries, it is necessary to determine complications and causes of death at all stages of medical care.
Most authors believe that results of polytrauma treatment mainly depend on arrangement of specialized medical care. Particularly, the importance of prehospital care is accentuated since timeliness and quality of care are the main conditions, which influence on outcomes and treatment of injuries [6, 7, 8]. However, some clinicians note the absence of the uniform approach to estimation of condition and management strategy for patients with polytrauma, resulting in realization of inappropriate care [6, 9].
The main direct causes of death in quite healthy people are acute massive blood loss and TBI [4, 9, 10, 11]. According to S.R. Heckbert et al., the mortality in patients with hemorrhagic shock, which develops at the background of trauma, can reach 54 % [12]. Moreover, 30 % of patients, which are admitted with hemorrhagic shock, die within 2 hours after admission to the intensive care unit [10]. The golden hour concept is actual for this category of patients since the first post-injury hour mainly influences on survival of a critically ill patient [11, 13]. At the prehospital stage, the successful solution of this problem requires for reduction of time of medical care initiation and transportation time in combination with use of standards of diagnosis and treatment [14]. A decrease in mortality can happen only in a case of rapid and correct high tech care. Objective findings are required for this.
The absence of Russian data on structure of death from polytrauma initiated us to conduct our own analysis. We tried to investigate this issue and used forensic medical protocols with case officer's description, request form for emergency care, discharge summaries and conclusion by forensic medical experts.
Objective − to determine the main causes of severe injuries and their complications, which lead to death of victims, as well as determination of main trends of management of trauma patients from the moment of injury, and solution of the issue on mortality reduction.
MATERIALS AND METHODS
The analysis included a sample of 169 medical forensic protocols of patients who died from injuries in Moscow in December, 2017. All lethal cases were associated with traumatic injuries as main causes of death or cause promoting it. Since we oriented to patients with polytrauma, the study excluded patients with single injuries and/or patients with ISS < 17 (71 persons). Therefore, the study included 98 autopsy cases. An injury type, an injury cause, complications and associated clinical conditions, time of hospital admission, time from injury to lethal outcome, and immediate cause of death were estimated for each patient. In some patients, the causes of death were concurrent. AIS and ISS were used in the study. The critical level of significance was 0.05.
The ethical committee approval was not required due to epidemiological characteristics of the study.
RESULTS
Among all registered lethal cases, most patients (98 (58 %)) died as result of polytrauma. The study included 68 (69.4 %) men and 30 (30.6 %) women, the mean age of 48. The main case of an injury was a road traffic injury (railway or road traffic accident − 45 (45.9 %)) and falling from height > 3 m − 37 (37.7 %). Also there were 8 criminal deaths, 4 falling from height < 3 m and two lethal outcomes after industrial accidents. The circumstances of injury were unknown in 2 cases. Blunt injuries were found in 92 (93.8 %) cases, penetrating ones − in 6 (6.1 %). Alcohol was found in one-third of deceased (31 (31.6 %), mean level of 2.3 ‰), narcotic agents − in 2 (2 (2.0 %)); 8 cases were without any data.
Most patients die at the accident site: 73 (74.5 %), 3 − at the prehospital stage in the emergency car (3.1 %), others − in ICU (22 (22.4 %)). According to forensic medical conclusions, the bleeding was the main cause of death (74 (75.5 %)), followed by brain injury in 54 (55.1 %) cases and multiple skeletal or organ injuries in 36 (36.7 %) cases. This term means appearance of multiple fractures and organ injuries after high energy trauma, with difficulties in determination of a death cause owing to insufficient data. TBI-associated brain dislocation was in 9 (9.2 %) cases, as well as pulmonary embolism, with fat embolism in 7 (7.1 %) and thromboembolism in 2 (2 %). Pneumonia and sepsis were in 8 (8.2 %) and 4 (4.1 %) cases, correspondingly. The incidence of clinical conditions complicating the injury was: hemothorax − 61 (62.2 %), hemoperitoneum − 50 (51 %), their combination − in 15.3 % of patients. Pneumothorax was in 18 cases (18.4 %), bilateral one − in 5 (5.1 %). Also 2 massive retroperitoneal bleedings and 1 heart tamponade were found.
ISS was estimated posthumuosly. Its mean level was 53.8, whereas mean ISS on the basis of clinical diagnosis and estimated injuries was 36.8.
The dependence of the death causes on ISS and duration of patients' life was estimated (Fig. 1).
Figure 1
Distribution of causes of death in dependence on time and ISS
In the first hours after trauma, the most significant and most common lethal factor was bleeding (5 ± 22.1 hours, p = 0.003) with mean ISS of 58.4 ± 19.4 (p = 0.0003). Patients with multiple skeletal and organ injuries (24.0 ± 119.2 hours, p = 0.07) died within 24 hours, patients with brain injuries − later (35.2 ± 117.2 hours, p = 0.327). Pulmonary embolism developed on 8th day on average (p = 0.001). Pneumonia as a cause of death after trauma appeared approximately after 17 days (p < 0.0001). The figure 1 shows that the highest early mortality corresponds to ISS > 50, and late complications − ISS < 30. One should note that some patients had several causes of death during thanatogenesis: so a combination of cerebral injury and blood loss was noted in 20.41 %. A combination of cerebral injury, blood loss and multiple injuries happened in 16.33 % of cases. Blood loss and brain injury as single independent causes of death were in 15.31 % and in 10.21 %, correspondingly.
In our sample, the presence of hemopericardium was in patients with ISS − 75. Hemoperitoneum and hemothorax were associated with ISS about 60. Pneumothorax and brain dislocation appeared in patients with ISS of 49.0 ± 18.8 (p = 0.33) and 35.8 ± 18.2 (p = 0.001), correspondingly. The mean value for bilateral pneumothorax was 56.2 ± 17.7 (p = 0.757). One should note that such complications as pulmonary embolism, sepsis and pneumonia show lower ISS. It is associated with higher life span of such patients (Fig. 2).
Figure 2
ISS value in relation to complications
As we mentioned, quite high proportion of lethal outcomes consists of hemorrhage-related complications. Therefore, time of transportation to the hospital, and quality of medical care are important. According to our data, the mean time from a call receive to hospital admission was approximately 58 minutes, and the period from trauma to a lethal outcome − 37.4 ± 141.7 hours.
We conducted a correlation analysis of data from admitted patients on the basis of ISS indices calculated according to clinical diagnosis and autopsy (Fig. 3). In most cases, a clinical variant corresponded to autopsy data: the diagrams are quite similar, but we found some cases with higher clinical ISS, sometimes very significant. Under-diagnosis with ISS was in single cases. However, several injuries were found: 2 cases of thromboembolism, 2 cases of fat embolia, 4 cases of rib fractures, 1 case of spleen rupture, and bilateral hemothorax and massive unilateral hemothorax in 2 cases. It meant insufficient diagnostics and possible diagnostic errors.
Figure 3
Correlation relationship of ISS according to clinical data and postmortem examination data
Also we conducted the correlation analysis of ISS values and death time in dependence on causes of lethal outcomes (Fig. 4). On the basis of our data, the dependence of injury severity and death time was observed at stages of so-called early causes of death: bleeding, multiple skeletal and organ injuries, brain injury (as one can see, the initial points of the diagrams have similar structure). Subsequently, the dependence decreases slightly, and it makes sense since the lower severity of injuries, the higher time of life span and development of late complications such as pneumonia and thromboembolism.
Figure 4
Correlation relationship of ISS and death time according to causes of a lethal outcome
DISCUSSION
Time and site
Like other authors, we believe that the time is the most important resource. Brian J. Eastridge et al. report on 50 % of deaths within the first two hours after trauma. Subsequently, up to 30 % of deaths appear within the first six hours [11]. Therefore, it is necessary to reduce time of hospital admission.
In Moscow and abroad, car and helicopter emergency medical teams are used for transportation of patients. In our sample, all patients were admitted with ground transport. We have not any data relating to time of arrival of the ambulance car to the accident site since the time is not indicated in forensic protocols. However, the time from a call (approximate time of an accident) to hospital admission is indicated − 58 minutes.
According to the data from the official site of the Moscow mayor, the mean time of arrival of emergency medical teams in Moscow in 2017 was 9.4 minutes. In Saint Petersburg, the mean time of arrival to the accident site was 10 ± 3 minutes, the mean time of care − 35 ± 7 minutes [15]. In Japan, in Chiba prefecture, the mean interval between an accident and contact with a doctor in a hospital was 47 minutes [16]. In Tokyo, the time of arrival of emergency medical team is 5.5 minutes [14]. Therefore, as compared to our colleagues, there is time delay during transportation from the accident site.
According to some foreign authors, approximately 14-47 % of deaths happen at the prehospital stage [4, 10]. In Colorado, more than a half of all deaths happened at the accident site − DOS (died on scene, 52 %). The proportion of deaths at admission (DOA) − 30 %. Finally, only small amount of patients (13.3 %) died at the hospital stage (DAH − died at hospital) [17]. In our case, DOA − 3 % (3), DAH − 22.4 % (22), DOS − 74.5 % (73). As compared to the data from USA, the high proportion of deaths on site is in Moscow. Most patients had 75 points of ISS (43 persons), i.e. fatal injuries. At the same time, some victims who died on site had low or mean ISS, i.e. low probability of death. Probably, it is associated with non-efficient prehospital care. Long time of arrival of car ambulance, and no aid from bystanders can be the causes. Low percentage of deaths during transportation with ambulance car supposes the importance of the problem of these two factors.
Severity of injuries and complications
Comparing the data of death distribution according to ISS, we can say about partial fit of our data with data from colleagues from Sweden. So, in our study, 43.8 % of patients had fatal injuries (AIS = 6, ISS = 75), and 10.2 % of patients had ISS < 25. According to E. Henriksson et al., approximately a half of victims (48 %) had ISS = 75. Proportion of victims with ISS < 25 was 12 % [18]. E. Henriksson and K. Soreide mention the head injury as the main cause of death [18, 19]. In our case, the earliest and most common (75.5 %) cause of lethal outcomes was internal bleeding (the mean time of 5 hours). Hemothorax (62.2 %) and hemoperitoneum (51 %) were common. These complications appeared in patients with serious complications with mean ISS of 60.8 ± 16.2 (p = 0.001).
Multiple skeletal and organ injuries (24 hours per 35 persons) was the second cause of death, followed by TBI (the mean time of mortality − 1.4 days per 56 persons). Like in our colleagues, despite the fact that death time in patients with TBI does not take the leading place, it takes the very important position among early causes of death since it was in more than a half of patients (55.1 %).
One should note that hemoaspiration was found in one case with a patient who died on site. Probably, it played the main role, considering mortality of 5-7 % for ISS of 17.
The issue of death prevention
Some foreign authors consider such studies in the context of potentially preventable deaths, with their aims as determination of various errors at all stages of diagnosis and treatment. According to Roman Pfeifer et al., one of the main causes (27-58 %) of lethal outcomes is delayed treatment and errors in management (40-60 %) and treatment (50-76.6 %) [4]. According to other authors, late diagnosis and errors in treatment promoted 63 % of lethal outcomes [20]. The main role is given to delay in medical care and errors at the prehospital stage which are responsible for high proportion of preventable deaths [1, 21].
During correlation analysis of ISS with clinical and autopsy data, a partial difference towards overestimate of points at the prehospital stage was found. Possibly, it is associated with insufficiency of diagnosis or incomplete clinical data in severe patients. It gives to a doctor an opinion on higher amount of injuries as compared to real number. Also one should consider that some fatal injuries and complications were not found in some patients. It means insufficient diagnostics.
On the basis of our data, we and other authors think that practical side of prevention of death from injuries should include manipulations with first care arrangement such as airway management and bleeding arrest within the interval from an accident to arrival of the ambulance car [10, 22, 23, 24]. According to some Russian authors, a quarter of deceased patients could be alive if first medical care for some conditions would be realized [8]. Therefore, the role of a bystander on the accident site is important. Unfortunately, we have no data on realization of first aid before arrival of the ambulance car. However in a study by GJ Oliver et al., bystanders performed some actions only in 25 % of cases. He considered it as the low value [22].
The procedures for bleeding control proved their efficiency in decrease of mortality from hemorrhagic injuries. Advancement of these new strategies at the prehospital stage can be helpful [11, 17]. We agree with Russian and foreign authors in issues of necessity for formation of specialized trauma teams with use of helicopter, with special training and equipment for life-saving manipulations [7, 14, 15, 18]. The use of invasive techniques for bleeding arrest (REBOA) gives excellent results in foreign countries [4]. One has to minimize the time of arrival of the ambulance car to the accident site and to accelerate the time of hospital admission. According to our data, the mean time of transportation is quite high.
Also we think that it is necessary to conduct the systematic analysis of prevention of deaths from injuries, with estimation of injuries and complications in patients with potentially preventable deaths. In some cases, an increase in preventable deaths in some facilities must be the impetus for estimation of causes and for decrease of their incidence, but not the reason for various forensic examination [25]. These issues are solved by means of identification of errors at all stages of trauma care. The analysis and registration of errors is a big step on the way of improvement in quality of aid for patients with severe injuries.
CONCLUSION
1. Most patients of Moscow region died before arrival of the ambulance car as result of severe concomitant injuries.
2. In patients with ISS > 50, the probability of lethal outcome was higher in the early period.
3. ISS indices, which are calculated on the basis of clinical and autopsy data, show correlation, but significant non-diagnosed injuries and complications exist.
4. The main early and common cause of death is bleeding. The head injury takes the second place. The third place is taken by low invasive techniques for balloon occlusion of the aorta.
5. Severity of injuries and death time are correlated in relation to the causes of lethal outcome.
6. Comparison of our results and the studies by foreign authors show the high proportion of prehospital mortality. It supposes the necessity for research of the problem of mortality in patients with polytrauma in RF in the concept of preventable deaths.
Information on financing and conflict of interests
The study was conducted without sponsorship. The authors declare the absence of any clear or potential conflicts of interests relating to publication of this article.