Delta shock index predicts injury severity, interventions, and outcomes in trauma patients: A 10-year retrospective observational study

Table 1 Demographics and clinical characteristics based on delta shock index in trauma patients (n = 13212), n (%)/mean ± SD

	DSI ≤ 0.1 (n = 10039; 76%)	DSI > 0.1 (n = 3173; 24%)	P value
Age (years)	33.6 ± 14.5	32.2 ± 15.1	0.001
Males	9113 (90.8)	2860 (90.1)	0.28
EMS time (min)	70.6 ± 27.9	70.8 ± 28.3	0.67
Scene time (min)	24.2 ± 15.8	26.9 ± 18.1	0.001
Level 1 trauma activation code	1350 (15.4)	1058 (37.6)	0.001
Level 2 trauma activation code	7177 (82.0)	1712 (60.9)	0.001
Vital signs at scene
Pulse rate	94.4 ± 19.8	88.1 ± 21.5	0.001
Systolic blood pressure	128.7 ± 21.9	138.1 ± 25.2	0.001
Diastolic blood pressure	80.1 ± 16.7	86.7 ± 21.8	0.001
Respiratory rate	19.3 ± 4.3	19.7 ± 5.4	0.001
GCS (mean, 95%CI)	14.30 (14.26-14.34)	13.03 (12.90-13.15)	0.001
Vitals at TRU
Pulse rate	87.3 ± 16.8	103.4 ± 22.4	0.001
Systolic blood pressure	131.2 ± 18.9	115.4 ± 21.6	0.001
Diastolic blood pressure	79.4 ± 13.4	72.5 ± 16.6	0.001
Respiratory rate	19.4 ± 3.2	20.3 ± 4.3	0.001
GCS (mean, 95%CI)	14.08 (14.03-14.14)	12.22 (12.05-12.38)	0.001
Cardio-pulmonary resuscitation	131 (1.3)	184 (5.8)	0.001
ED disposition
Operating room	1698 (16.9)	720 (22.7)	0.001
Intensive care unit	1917 (19.1)	1065 (33.6)	0.001
Step-down unit	107 (1.1)	21 (0.7)	0.001
Floor	5735 (57.1)	1261 (39.7)	0.001
High dependency unit	214 (2.1)	45 (1.4)	0.001
Transfer to another facility	54 (0.5)	6 (0.2)	0.001
Home	305 (3.0)	41 (1.3)	0.001
Died	9 (0.1)	14 (0.4)	0.001
Revised trauma score	7.6 ± 0.8	6.9 ± 1.5	0.001
TRISS	0.97 ± 0.08	0.90 ± 0.19	0.001
Injury severity score	11.3 ± 8.2	15.9 ± 11.3	0.001
Head AIS	3.3 ± 0.9	3.6 ± 1.0	0.001
Chest AIS	2.6 ± 0.7	2.7 ± 0.7	0.001
Abdomen AIS	2.5 ± 1.2	2.6 ± 1.0	0.04
Pelvis AIS	2.1 ± 0.5	2.3 ± 0.7	0.001

ED: Emergency department; AIS: Abbreviated injury score; TRISS: Trauma score and injury severity score; GCS: Glasgow coma scale; EMS: Emergency medical services time; DSI: Delta shock index.

Table 2 Comparison of management and outcome based on delta shock index, n (%)/mean ± SD/ mean, 95%CI

	DSI ≤ 0.1 (n = 10039; 76%)	DSI > 0.1 (n = 3173; 24%)	P value
Intubation	1315 (13.1)	1108 (34.9)	0.001
Intubation location
Scene	433 (33.0)	539 (49.0)	0.001
Trauma resuscitation unit	550 (42.0)	397 (36.1)	0.001
Operating room	226 (17.2)	128 (11.6)	0.001
Intensive care unit	72 (5.5)	27 (2.5)	0.001
Floor	12 (0.9)	3 (0.3)	0.001
Referring facility	18 (1.4)	6 (0.5)	0.001
FAST done	9570 (95.3)	3047 (96.0)	0.09
Negative	8786 (93.9)	2638 (88.5)	0.001
Positive	445 (4.8)	304 (10.2)	0.001
Undetermined	125 (1.3)	39 (1.3)	0.001
Exploratory laparotomy	380 (3.8)	281 (8.9)	0.001
ECMO	8 (0.1)	11 (0.3)	0.001
REBOA	1 (0.0)	3 (0.1)	0.01
Prehospital fluid administered	3626 (36.1)	1392 (43.9)	0.001
Prehospital fluid (mL)	466 ± 399	585 ± 472	0.001
Blood transfusion	1358 (13.5)	1039 (32.7)	0.001
Total blood units transfused	3 (1-73)	4 (1-68)	0.001
Massive transfusion protocol	155 (1.5)	269 (8.5)	0.001
In-hospital complications
Sepsis	98 (1.0)	87 (2.7)	0.001
Ventilator-associated pneumonia	263 (2.6)	226 (7.1)	0.001
Acute respiratory distress syndrome	56 (0.6)	51 (1.6)	0.001
Thromboembolic events	46 (0.5)	39 (1.2)	0.001
Abdominal compartment syndrome	3 (0.05)	7 (0.2)	0.002
Multiorgan failure	6 (0.1)	12 (0.4)	0.001
Disseminated intravascular coagulation	1 (0.01)	4 (0.1)	0.01
Hospital length of stay	5 (1-505)	7 (1-360)	0.001
ICU length of stay	3 (1-155)	5 (1-161)	0.001
Ventilatory days	3 (1-180)	5 (1-115)	0.001
Mortality	141 (1.4)	231 (7.3)	0.001
Death on arrival	1 (0.02)	6 (0.2)	0.001
Discharge disposition
Home	8840 (88.3)	2376 (75.1)	0.001
Rehabilitation	461 (4.6)	254 (8.0)	0.001
Long-term care	72 (0.7)	61 (1.9)	0.001
Transfer to another hospital	499 (5.0)	242 (7.6)	0.001
Died	141 (1.4)	231 (7.3)	0.001

FAST: Focused assessment with sonography in trauma; ECMO: Extracorporeal membrane oxygenation; REBOA: Resuscitative endovascular balloon occlusion of the aorta; DSI: Delta shock index.

Table 3 Univariate correlation between delta shock index and other relevant covariates

Variable	Pearson correlation (r)	P value
Age	0.002	0.79
Injury severity score	0.223	0.001
Glasgow coma scale	-0.239	0.001
TRISS	-0.297	0.001
Revised trauma score	-0.301	0.001
Blood transfusion units	0.205	0.001
Head AIS	0.166	0.001
Chest AIS	0.065	0.001
Hospital length of stay	0.142	0.001
ICU length of stay	0.109	0.001

TRISS: Trauma score and injury severity score; AIS: Abbreviated injury score; ICU: Intensive care unit.