INFLUENCE OF STRUCTURE AND CHARACTER OF COURSE OF MULTIPLE ORGAN DYSFUNCTION ON OUTCOME OF POLYTRAUMA Gabdulkhakov R.M., Rakhimova R.F., Lutfarakhamanov I.I., Bulatov R.D.

Bashkir State Medical University,

City Clinical Hospital No.21, Ufa, Russia

During the last decades, the rate of road traffic injuries has shown the characteristics of epidemy, with increasing scales of natural disasters and increasing incidence of technological disasters. Injuries have acquired the severe and disabling pattern with simultaneous injury to two and more anatomical regions of the body, development of shock and multiple organ dysfunction [1-3]. The severe injury has become the main cause of mortality in the population at the age before 40.

The strategy for timely and adequate correction of disorders of functions of vital organs and systems, and also subsequent efficient control of them will allow decreasing the quality of treatment and decreasing mortality [4-8].

Objective – to study the effect of the structure and nature of the course of multiple organ dysfunction on the outcome of polytrauma.

MATERIALS AND METHODS

A prospective randomized controlled study included 231 patients with polytrauma (ISS > 15). There were 60.2 % of men at the age of 18-86 (the mean age of 43.6 ± 16.8) who were admitted to the intensive care unit of the multi-profile City Clinical Hospital No.21, Ufa, in 2001-2016. The exclusion criteria were pregnancy, severe decompensated concurrent diseases and death within 48 hours after injury.

The quantitative estimation of acute multiple organ dysfunction (MOD) was conducted with Multiple Organ Dysfunction score (MODS) [9, 10].

Logistic regression analysis and ROC-analysis were used for estimation of influence of structure and features of MOD on patients’ survival. ROC-analysis was interpreted with estimation of area under curve (AUC). The predictive power of the model was high at AUC > 0.80. Odds ratio (OR) was used for estimation of a degree of influence of the risk factors of hospital death on polytrauma outcome. AUC and OR were calculated with 95 % CI.

Med Calc and SPSS were used for statistical preparation of the materials. Mean arithmetic (M) and standard deviation (SD) were calculated. The analysis of variance was used for comparison of quantitative data in the samples, χ2-test – for analysis of categorical data. The differences were statistically significant at p < 0.05.

The examinations corresponded to WHO Helsinki Declare – Ethical Principles for Medical Research with Human Subjects and were approved by the ethical committee of Bashkir State Medical University (the protocol No.22, 12 December 2016).

RESULTS AND DISCUSSION

AIS was 9.74 ± 3.51, ISS – 21.4 ± 13.62 and GCS – 11.5 ± 2.45 in the study group at admission. The hospital mortality was 23.8 % (55 patients). The intensity of multiple organ dysfunction was 4.9 ± 3.38 according to MODS. Among MOD syndromes, CNS dysfunction (85.3 %), respiratory (66.2 %), cardiovascular (60.6 %) and renal (52.2 %) dysfunctions were dominating. Hemostasis system and liver dysfunctions were less frequent (33.8 % and 22.9 % correspondingly).

The table 1 shows the distribution of MOD syndromes according to their severity, as well as mortality according to severity of organ dysfunction. Among severe organ dysfunctions (3-4 points), the most common ones were CNS, cardiovascular and respiratory dysfunctions. High MODS was associated with high mortality: the mortality was 100 % in patients with hemostasis system dysfunction of 4 points, and about 90 % for CNS, cardiovascular and respiratory dysfunctions.

Table 1

Incidence of organ dysfunctions and mortality (n = 231)

System/organ	Value	Number of points
System/organ	Value	0	1	2	3	4
CNS	Incidence, %	14.7	36.5	30.7	13.9	4.3
CNS	Mortality, %	2.9	4.8	28.2	64.5	91
Cardiovascular	Incidence, %	39.4	35.7	11.3	10.4	3.5
Cardiovascular	Mortality, %	9.9	13.4	44.4	69.6	87.5
Respiratory	Incidence, %	33.8	38.5	17.7	6.1	3.9
Respiratory	Mortality, %	2.6	18.0	46.3	71.4	88.9
Renal	Incidence, %	46.8	39.4	9.6	2.61	1.74
Renal	Mortality, %	14.8	26.4	40.9	50.0	75.0
Hemostasis	Incidence, %	66.2	18.2	11.3	3.9	0.4
Hemostasis	Mortality, %	13.7	31.0	50.0	77.8	100
Liver	Incidence, %	77.1	20.3	1.74	0.87	-
Liver	Mortality, %	21.9	25.5	60	100	-

Multiple organ disorders were identified in most patients. Dysfunction of a single organ or system was diagnosed in only 6 % of patients. According to total number of points of organ dysfunctions, all patients were distributed in this way: the highest number (120 persons) were patients with 1-4 points (mortality – 5 %); 5-8 points – 73 patients (mortality – 27.4 %); 9-12 points – 31 patients (mortality – 71 %); 13 and more points – 7 patients (mortality – 100 %).

Dysfunction of 2 and more organs and systems appeared in 217 (94 %) patients. Moreover, in 78 %, MOD disappeared in 48 hours during intensive care. We can suppose that almost 1/3 of the patients had MOD which developed as response to a severe injury and showed the transitory pattern. Other 2/3 of the patients had MOD, which disappeared later, with its manifestation worsening the prognosis [11, 12].

During 3 days, we performed a comparative study of intensity of MOD in deceased patients and survivals. Within the first 24 hours, severity of MOD in deceased patients was 2.1 times higher than in survived ones (p < 0.001): 3.79 ± 2.63 points (n = 176) in survived, 7.96 ± 2.89 points (n = 55) in deceased patients. By the third day, a response to intensive care, the decrease in MOD severity was only 14.7 % in deceased patients (p = 0.033), whereas survived patients demonstrated 4-folf decrease (p < 0.001) as compared to the first day.

Therefore, the activity of MOD at admission, and the subsequent intensity of its manifestations are the important predictors of poor outcome [13-15].

With logistic regression and ROC-analyses, we estimated the predictive significance of the dynamic examination of MOD intensity (the table 2). The conducted studies showed that sensitivity and AUC of MODS had increased significantly during estimation of prognosis on the second day and especially on the third day (p < 0.01). Manifestation of MOD caused 1.49-fold increase in probability of hospital death on the second day (p < 0.01), 2.75 increase on the third day (p < 0.001) as compared to the first day.

Table 2

ROC areas and probability of lethal outcome in dynamic examination of number of points (n = 231)

Value	Time of examination, days
Value	1	2	3
AUROC (95% CI)	0.85 (0.787-0.893)	0.94*** (0.898-0.965)	0.97 *** (0.943-0.990)
Cut point	> 4	> 3	> 3
Sensitivity	44.4	62.9*	88.9**
Specificity	95.6	95.5	95.5
Accuracy	83.5	87.8	93.9
Regression ratio (b_k)	0.48 ± 0.07	0.88 ± 0.12	1.49 ± 0.25
OR (95% CI)	1.62 (1.41-1.85)	2.41** (1.91-3.06)	4.45*** (2.75-7.21)

Note: * – p < 0.05; ** – p < 0.01; *** – p < 0.001 in comparison with the first 24 hours; OR – odds ratio.

Therefore, realization of dynamic estimation of MOD severity as a response to adequate intensive care is more important during estimation of prognosis.

A degree of influence on an outcome of some syndromes of organ dysfunctions is important from scientific and practical perspectives. The logistical regression analysis showed that along with a number of affected organs and systems, the main factors of the outcome were dysfunctions of CNS, cardiovascular, respiratory and hemostatic systems (p < 0.01) (the table 3). However renal and hepatic dysfunctions were not associated with lethal outcome (p > 0.05).

Table 3

Relationship between organ dysfunction and hospital mortality

System/organ	Regression ratio (b_k)*	р	OR (95% CI)
Respiratory (n = 152)	0.67 ± 0.24	0.0053	1.95 (1.22-3.12)
Cardiovascular (n = 140)	1.20 ± 0.22	0.0001	3.31(2.16-5.07)
CNS (n = 196)	1.82 ± 0.28	0.0001	6.17 (3.60-10.59)
Renal (n = 120)	0.32 ± 0.24	0.178	1.38 (0.86-2.21)
Hemostasis (n = 76)	1.03 ± 0.38	0.006	2.81(1.34-5.90)
Liver (n = 54)	0.649 ± 0.623	0.297	1.91(0.56-6.49)
Number of organs (n = 172)	1.21 ± 0.19	0.0001	3.36 (2.30-4.91)

Note: * standard error.

At the next stage, we tried to estimate the influence of organ dysfunctions on survival after 7 days. The patients who died within the first 7 days were excluded. Respiratory (n = 124; р = 0.001; OR = 2.64 (95 % CI = 1.48-4.73) and hepatic (n = 44; р = 0.032; OR = 4.73 (95 % CI = 1.14-19.5) dysfunctions demonstrated higher influence on the outcome after 1 week. The influence of CNS and cardiovascular dysfunctions was still high, but to a lesser degree as compared to the first day (p < 0.01). Renal and hemostasis dysfunctions lost their actuality (p > 0.05).

Therefore, in patients with polytrauma, dysfunctions of CNS, respiratory, cardiovascular and hemostasis systems, as well as a number of organ dysfunctions, showed the highest influence on hospital mortality. After one week, the influence of respiratory and hepatic dysfunctions increases. The influence of other organs and systems show a trend to decrease.

CONCLUSION

1. In patients with polytrauma and ISS > 15, the main MOD syndromes are CNS (85.3 %), respiratory (66.2 %) and cardiovascular (60.6 %) dysfunctions.

2. Dysfunctions of two and more systems and organs are noted in 94 % of patients. Moreover, 1/3 (35.9 %) had MOD which disappears within 48 hours, i.e. it has the transitory pattern.

3. The predictive value of MODS increases in the process of its dynamic examination.

4. Dysfunctions of CNS, cardiovascular, respiratory and hemostasis systems, as well as a number of organ dysfunctions, make the highest influence on polytrauma outcome. After one week, the increase in influence of respiratory and hepatic dysfunctions appears, whereas the influence of dysfunctions of other organs and systems shows a trend to decrease.

Information on financing and conflicts 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.