Abstract
Background
Studies show increased early and overall mortality at level II compared to level I trauma centers in hemodynamically unstable patients. We hypothesize there is no mortality difference between level I and level II centers applying more contemporary data.
Study design
Utilizing the 2017 Trauma Quality Program Participant Use File (TQP-PUF), we identified adult patients (age >14 years) who presented to an American College of Surgeons (ACS) verified level I or II center with hypotension (systolic blood pressure [SBP] < 90 mmHg). Logistic regression was performed to identify adjusted associations with mortality.
Results
A total of 7,264 patients met the inclusion criteria, of whom most were males (4,924 [67.8%]) with blunt trauma (5,924 [81.6%]) being predominated. Mean admission SBP was 73.2 (±13.0) mmHg. There were 1,097 (15.1%) deaths. Level I admissions (4,931 (67.9%]) were more likely male (3,389 [68.7%] vs. 1,535 [65.8]; p=0.012), non-white (3,119 [63.3%] vs. 1,664 [71.3%]; p<0.001), a victim of penetrating trauma (933 [18.9%] vs. 385 [16.5%]; p=0.015), and more severely injured (mean Injury Severity Score: 19.3 [±15] vs. 16.7 [±13.7]; p<0.001). Level II admissions (2,333 [32.1%]) were older (46.8 [±18.5] vs. 50.3 [±20.1] years; p<0.001) with more co-morbidities (mean Charlson Comorbidity Index: 1.43 [±2] vs. 1.77 [±2.2]; p<0.001). Adjusted mortality between level I and II admissions was similar (766 [15.5%] vs. 331 [14.2%]; p=0.918). Early hourly mortality also did not differ.
Conclusion
There is no overall or hourly mortality discrepancy between ACS-verified level I and II centers for patients presenting with hypotension. This potentially relates to the use of more contemporary data gathered after implementation of updated verification requirements.
Keywords: mortality, trauma center, verification, american college of surgeons, unstable trauma
Introduction
Previous literature outlines significant outcome differences between level I and level II trauma centers. Superior outcomes are reported at level I centers for the severely injured [1,2], traumatic brain injury (TBI) patients [3,4], those with other specific injuries [5], and overall mortality [6,7]. Less prevalent are studies showing improved outcomes or equivalency at level II centers [8-11]. Of significance to our study, previous data show that trauma patients presenting with hemodynamic instability have significantly lower mortality in level I versus level II centers and that this discrepancy is sustained during the first hours of admission [2]. It was hypothesized that level II centers have access to inferior resources. However, during the time many of these investigations were being reported, there were differences in clinical requirements at level I versus level II trauma centers.
Since 1976, the American College of Surgeon Committee on Trauma (ACS-COT) has issued trauma center resource guidelines. “Resources for the Optimal Care of the Injured Patient” (resources manual) emphasizes the importance of a systems-based approach mandating escalating clinical resources at higher level trauma centers [12]. The 2014 update mandated equivalent clinical resources at level I and II centers so that, theoretically, outcomes would be similar. However, there are little recent data to support this. We hypothesize that more contemporary analysis would support improved outcomes at level II centers relative to their level I counterparts in patients who present with hemodynamic instability [2].
Materials and methods
Utilizing the 2017 Trauma Quality Program Participant Use File (TQP-PUF), we identified adult patients (age >14 years) who presented to an ACS-COT verified level I or II trauma center with hemodynamic instability (systolic blood pressure [SBP] < 90 mmHg) [2]. We excluded patients with isolated TBI and interfacility transfers. Isolated TBI was identified by an Abbreviated Injury Scale (AIS) score for head of ≥3 with an AIS score for all other body regions of <3 [3]. We extracted all pertinent demographic and injury variables. This included, but was not limited to, gender, race, E code mechanism (mechanism), admission Glasgow Coma Scale (GCS) score, Injury Severity Score (ISS), and the presence of medical co-morbidities (Charlson Comorbidity Index [CCI]). Outcome variables include ICU and hospital lengths of stay (LOS) and in-hospital mortality.
Continuous variables were converted to dichotomous variables at clinically significant cut-points. This included, but not limited to, age (> 60 years), hypoxia (O2 saturation < 93%), severe TBI (admission GCS < 9), severe injury (ISS > 15), and CCI ≥ 3. Demographic and injury variables were compared between the groups admitted to a level I versus level II center. Similarly, variables were studied for their association with mortality. Univariate analysis was performed using Student’s t-test or ANOVA (analysis of variance) for continuous variables and X2 for dichotomous variables. All variables with a p-value of <0.05 on univariate analysis were then entered into logistic regression to determine adjusted mortality outcomes, with admission to a level II being added to the model. Results are reported as raw numbers, percentages, and odds ratios with 95% confidence intervals with p-values where appropriate. SPSS Version 21 (IBM Corp., Chicago, IL, USA) was used for statistical analysis. Comparisons were considered statistically significant with a p-value of <0.05.
Results
There were 7,264 patients meeting the inclusion criteria (Figure 1). Most patients were male (4,924 [67.8%]) and white (4,783 [65.8%]). Mean age was 47.9 (± 19.5) years. Primary mechanisms were occupants in motor vehicle trauma (1,808 [24.9%]) followed by falls (1,346 [18.5%]). The study group was severely injured with a mean ISS of 18.5 (±14.6). Mean ICU and hospital LOS were 8 (±9.5) and 11.7 (±15.1) days, respectively. There were 1,097 (15.1%) in-hospital deaths (Table 1).
Table 1. Hypotensive (SBP < 90 mmHg) patients admitted to an ACS-COT level I or II trauma center.
Data are expressed as raw numbers, percentages, and means with standard deviations.
ACS-COT, American College of Surgeon Committee on Trauma; CCI, Charlson Comorbidity Index; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; CVA, cerebrovascular accident; ED, emergency department; HTN, hypertension; ICU, intensive care unit; ISS, Injury Severity Score; LOS, length of stay; MVT, motor vehicle traffic; OR, operating room; SBP, systolic blood pressure; TBI, traumatic brain injury
| Variable | n or mean (% or SD) |
| Study patient | 7,264 |
| Level I admission | 4,931 (67.9%) |
| Level II admission | 2,333 (32.1%) |
| Demographics | |
| Gender (male) | 4,924 (67.8%) |
| Mean age (years) | 47.9 (±19.5) |
| Race | |
| Asian-Pacific Islander | 147 (2.1%) |
| Black | 748 (10.3%) |
| Other | 1,586 (21.8%) |
| White | 4738 (65.8%) |
| Mechanism (E code) | |
| Cut/pierce | 737 (10.1%) |
| Fall | 1,346 (18.5%) |
| Fall from height | 556 (7.7%) |
| Firearm | 1,096 (15.1%) |
| MVT-occupant | 1,808 (25%) |
| MVT-motorcycle | 553 (7.6%) |
| MVT-pedestrian | 478 (6.7%) |
| Pedestrian/cyclist | 276 (3.9%) |
| Struck by/against | 236 (3.2%) |
| Other classifiable | 143 (2.1%) |
| Trauma type | |
| Blunt | 5,924 (81.6%) |
| Penetrating | 1,318 (18.1%) |
| Thermal | 22 (0.3%) |
| Injury severity/demographics | |
| Admission mean ISS | 18.5 (±14.6) |
| ISS > 15 | 3,652 (50.3%) |
| Mean SBP (mmHg) | 73.2 (±13) |
| Admission hypoxia (SpO2 < 93%) | |
| TBI all | 2,032 (28%) |
| TBI mild | 909 (12.5%) |
| TBI moderate | 130 (1.8%) |
| TBI severe | 993 (13.7%) |
| Co-morbidities | |
| Alcohol abuse disorder | 757 (10.4%) |
| Anticoagulation | 462 (6.4%) |
| CHF | 276 (3.8%) |
| Cirrhosis | 159 (2.2%) |
| COPD | 467 (6.4%) |
| CVA | 142 (2%) |
| Dementia | 122 (1.7%) |
| Diabetes | 846 (11.6%) |
| HTN | 1,872 (25.8%) |
| Other | 1,068 (14.7%) |
| Psychiatric disorder | 939 (12.9%) |
| Renal dysfunction | 131 (1.8%) |
| Substance abuse | 783 (10.8%) |
| Chronic condition (any) | 5,111 (70.4%) |
| Mean CCI | 1.54 (±2.1) |
| Trauma center characteristics | |
| University teaching | 4,066 (56%) |
| Community teaching | 2,472 (34%) |
| Non-teaching | 726 (10%) |
| <200 beds | 419 (5.8%) |
| 201–400 beds | 2,013 (27.7%) |
| 401–600 beds | 1,978 (27.2%) |
| >600 beds | 2,854 (39.3%) |
| Primary payor characteristics | |
| Medicare/Medicaid | 3,189 (43.9%) |
| Private | 2,566 (35.3%) |
| Other | 344 (4.7%) |
| Uninsured | 1,165 (16.1%) |
| Treatment after ED | |
| Ward | 1,993 (27.4%) |
| OR | 2,395 (33%) |
| ICU | 2,722 (37.5%) |
| Death in ED | 154 (2.1%) |
| Outcome | |
| ICU LOS (days) | 8 (±9.8) |
| Hospital LOS (days) | 11.7 (±13.9) |
| Deaths | 1,097 (15.1%) |
Figure 1. Study population selection.
TQP-PUF, Trauma Quality Program Participant Use File
There were 4,921 (67.9%) patients admitted to a level I center, whereas 2,333 (32.1%) were treated at a level II center (Table 2). There was a slight male predominance (68.7% vs. 65.8%; p=0.012) at level I and the patients were less likely to be white (63.3% vs. 71.3%, <0.001). Level I admissions were also significantly younger (mean age: 46.8 [±19] vs. 50.3 [±20.1] years; p<0.001), with less comorbidities (mean CCI: 1.43 [±2] vs. 1.77 [±2.2]; p<0.001). Firearm injuries were more prevalent (16.9% vs. 11.3%; p<0.001). Level I admissions were more severely injured (mean ISS: 19.3 [±15] vs. 16.7 [±13.7]; p<0.001) and significantly more underwent surgery or angiography for hemorrhage control (not shown in table) (34.5% vs. 25.3%; p<0.001). The presence of a TBI was similar (27.8% vs. 28.3%; p=0.980). ICU LOS was not different but hospital LOS was longer at a level I center (mean 12.1 [±14] vs. 10.9 [±13.6] days; p<0.001). Mortality was higher at a Level I center; however, this was not statistically significant (15.5% vs. 14.2%, p=0.134).
Table 2. Comparison of admissions to level I versus level II trauma centers for hypotensive (SBP < 90 mmHg) patients.
Data are expressed as raw numbers, percentages, and means with standard deviations.
CCI, Charlson Comorbidity Index; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; CVA, cerebrovascular accident; ED, emergency department; HTN, hypertension; ICU, intensive care unit; ISS, Injury Severity Score; LOS, length of stay; MVT, motor vehicle traffic; OR, operating room; SBP, systolic blood pressure; TBI, traumatic brain injury
| Variable | Level I: 4,931 (67.9%) | Level II: 2,333 (32.1%) | OR/mean difference (95% CI), p-value |
| Demographics | |||
| Gender (male) | 3,389 (68.7%) | 1,535 (65.8%) | 1.143 (1.029–1.269), 0.012 |
| Mean age (years) | 46.8 (±19) | 50.3 (±20.1) | –3.467 (–4.423 to 2.511), <0.001 |
| Race | |||
| Asian-Pacific Islander | 111 (2.3%) | 36 (1.5%) | <0.001 |
| Black | 476 (9.7%) | 272 (11.7%) | |
| Other | 1,225 (24.8%) | 361 (15.5%) | |
| White | 3,119 (63.3%) | 1,664 (71.3%) | |
| Mechanism (E code) | |||
| Cut/pierce | 525 (10.6%) | 212 (9.1%) | <0.001 |
| Fall | 781 (15.8%) | 565 (24.2%) | |
| Fall from height | 360 (7.3%) | 196 (8.4%) | |
| Firearm | 833 (16.9%) | 263 (11.3%) | |
| MVT occupant | 1,362 (25.6%) | 546 (23.4%) | |
| MVT motorcycle | 280 (7.7%) | 173 (7.4%) | |
| MVT pedestrian | 327 (6.6%) | 151 (6.5%) | |
| Pedestrian/cyclist | 187 (3.8%) | 89 (3.8%) | |
| Struck by/against | 151 (3.1%) | 85 (3.6%) | |
| Other classifiable | 101 (2%) | 42 (1.8%) | |
| Trauma type | |||
| Blunt | 3,980 (80.7%) | 1,944 (83.3%) | 0.015 |
| Penetrating | 933 (18.9%) | 385 (16.5%) | |
| Thermal | 18 (0.4%) | 4 (0.2%) | |
| Injury severity | |||
| Mean ISS | 19.3 (±15) | 16.7 (±13.7) | 2.611 (1.893–3.329), <0.001 |
| ISS > 15 | 2,614 (53%) | 1,038 (44.5%) | 1.408 (1.275–1.554), <0.001 |
| Admission mean SBP (mmHg) | 73.4 (±18.5) | 72.8 (±20) | 0.637 (–0.300 to 1.574), 0.183 |
| Admission hypoxia (SpO2 < 93%) | 857 (42.8%) | 420 (18%) | 0.961 (0.845–1.093), 0.543 |
| TBI all | 1,372 (27.8%) | 660 (28.3%) | 0.977 (0.876–1.090), 0.980 |
| TBI mild | 587 (11.9%) | 322 (13.8) | <0.001 |
| TBI moderate | 96 (1.9%) | 34 (1.5%) | |
| TBI severe | 689 (14%) | 304 (13%) | |
| Co-morbidities | |||
| Alcohol abuse disorder | 515 (10.4%) | 242 (10.4%) | 1.008 (0.858–1.184), 0.929 |
| Anticoagulation | 294 (6%) | 168 (7.2%) | 0.817 (0.671–0.994), 0.043 |
| CHF | 180 (3.7%) | 96 (4.1%) | 0.883 (0.686–1.137), 0.334 |
| Cirrhosis | 116 (2.4%) | 43 (1.8%) | 1.283 (0.901–1.827), 0.166 |
| COPD | 306 (6.2%) | 161 (6.9%) | 0.893 (0.733–1.087), 0.259 |
| CVA | 85 (1.7%) | 57 (2.4%) | 0.700 (0.499–0.983), 0.039 |
| Dementia | 74 (1.5%) | 48 (2.1%) | 0.725 (0.503–1.046), 0.085 |
| Diabetes | 523 (10.6%) | 323 (13.8%) | 0.738 (0.637–0.856), <0.001 |
| HTN | 1,171 (23.7%) | 701 (30%) | 0.725 (0.649–0.809), <0.001 |
| Other | 700 (14.2%) | 368 (15.8%) | 0.770 (1.013–1.013), 0.076 |
| Psychiatric disorder | 652 (13.2%) | 287 (12.3%) | 1.086 (0.936–1.260), 0.275 |
| Renal dysfunction | 89 (1.8%) | 42 (1.8%) | 1.003 (0.692–1.452), 0.989 |
| Substance abuse | 561 (11.4%) | 222 (9.5%) | 1.221 (1.036–1.438), 0.017 |
| Chronic condition (any) | 3,418 (69.3%) | 1,693 (72.6%) | 0.854 (0.766–0.953), 0.005 |
| Mean CCI | 1.43 (±2) | 1.77 (±2.2) | 0.695 (0.623–0.773), <0.001 |
| Trauma center characteristics | |||
| University teaching | 3,802 (77.1%) | 279 (12%) | <0.001 |
| Community teaching | 1,139 (22.9%) | 1,343 (57.3%) | |
| Non-teaching | 0 (0%) | 711 (30.5%) | |
| <200 beds | 202 (4.1%) | 217 (9.3%) | <0.001 |
| 201–400 beds | 631 (12.8%) | 1,382 (59.2%) | |
| 401–600 beds | 1,625 (33%) | 353 (15.1%) | |
| >600 beds | 2,473 (50.2%) | 381 (16.3%) | |
| Primary payor characteristics | |||
| Medicare/Medicaid | 2,148 (43.6%) | 1,041 (44.6%) | <0.001 |
| Private insurance | 1,651 (33.5%) | 915 (39.2%) | |
| Uninsured | 901 (18.3%) | 264 (11.3%) | |
| Other | 231 (4.7%) | 113 (4.8%) | |
| Treatment after ED | |||
| Ward | 1,274 (25.8%) | 719 (30.8%) | <0.001 |
| OR | 1,700 (34.5%) | 695 (29.8%) | |
| ICU | 1,842 (37.4%) | 880 (37.7%) | |
| Death in ED | 115 (2.3%) | 39 (1.7%) | 1.405 (0.974–2.026), 0.081 |
| Outcomes | |||
| ICU LOS (days) | 7.9 (±9.2) | 8.2 (±10.2) | –0.262 (–0.843 to 0.318), 0.376 |
| Hospital LOS (days) | 12.1 (±14) | 10.9 (±13.6) | 1.269 (0.587–1.951), <0.001 |
| Mortality | 766 (15.5%) | 331 (14.2%) | 1.112 (0.968–1.279), 0.134 |
Deaths are compared to survivors in Table 3. Males (73.2% vs. 66.8%; p<0.001) and victims of firearm injuries (20.4% vs. 14.1%, <0.001) were more likely to die. The presence of a TBI (57.1% vs. 23%, <0.001) and higher mean ISS (32.6 [±17.1] vs. 16 [±12.6], p<0.001) were also associated with increased mortality. Increasing instability, reflected in lower mean admission SBP, also predicted death (mean SBP: 60.3 [±29.6] vs. 75.5 [±15.4] mmHg; p<0.001). Co-morbidities (CCI: 1.64 (±2.28) vs. 1.52 [2.02]; p=0.081)) were not statistically associated with death on univariate analysis, though age > 60 years (34.1% vs. 29.7%; p=0.003) predicted mortality.
Table 3. Comparison of deaths and survivors for hypotensive (SBP < 90 mmHg) trauma patients.
Data are expressed as raw numbers, percentages, and means with standard deviations.
CCI, Charlson Comorbidity Index; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; CVA, cerebrovascular accident; HTN, hypertension; ISS, Injury Severity Score; MVT, motor vehicle traffic; SBP, systolic blood pressure; TBI, traumatic brain injury
| Variable | Death: 1,097 (15.1%) | Survivor: 6,167 (84.9%) | OR/mean difference (95% CI), p-value |
| Demographics | |||
| Gender (male) | 803 (73.2%) | 4,121 (66.8%) | 1.356 (1.174–1.566), <0.001 |
| Mean age (years) | 48.1 (±21.5) | 47 (±19.1) | 0.216 (–1.035 to 1.466), 0.735 |
| Age > 60 years | 374 (34.1%) | 1,830 (29.7%) | 1.226 (1.070–1.405), 0.003 |
| Race | |||
| Asian-Pacific Islander | 24 (2.2%) | 123 (2%) | 0.924 |
| Black | 108 (9.8%) | 640 (10.4%) | |
| Other | 238 (21.9%) | 1,348 (21.9%) | |
| White | 727 (66.3%) | 4,056 (65.8%) | |
| Mechanism (E code) | |||
| Cut/pierce | 44 (4%) | 693 (11.2%) | <0.001 |
| Fall | 101 (9.2%) | 1,245 (20.2%) | |
| Fall from height | 84 (7.7%) | 472 (7.7%) | |
| Firearm | 224 (20.4%) | 872 (14.1%) | |
| MVT occupant | 316 (28.8%) | 1,492 (24.2%) | |
| MVT motorcycle | 110 (10%) | 443 (7.2%) | |
| MVT pedestrian | 105 (9.6%) | 373 (6%) | |
| Pedestrian/cyclist | 50 (4.6%) | 226 (3.7%) | |
| Struck by/against | 22 (2%) | 214 (3.4%) | |
| Other classifiable | 21 (2.8%) | 111 (1.8%) | |
| Trauma type | |||
| Blunt | 903 (82.3%) | 5,021 (81.4%) | 0.480 |
| Penetrating | 188 (17.1%) | 1,130 (18.3%) | |
| Thermal | 6 (0.5%) | 16 (0.3%) | |
| Injury severity | |||
| Mean ISS | 32.6 (±17.1) | 16 (±12.6) | 16.606 (15.748–17.465), <0.001 |
| ISS > 15 | 960 (87.5%) | 2,692 (43.7%) | 9.045 (7.511–10.894), <0.001 |
| Admission mean SBP (mmHg) | 60.3 (±39.6) | 75.5 (±15.4) | –15.253 (–16.424 to 14.083), <0.001 |
| Admission Hypoxia (SpO2 < 93%) | 375 (34.2%) | 904 (14.7%) | 3.024 (2.620–3.490), <0.001 |
| TBI all | 626 (57.1%) | 1,416 (23%) | 4.297 (3.761–4.909), <0.001 |
| TBI mild | 70 (6.4%) | 839 (13.6%) | <0.001 |
| TBI moderate | 11 (1%) | 119 (1.9%) | |
| TBI severe | 532 (48.5%) | 458 (7.4%) | |
| Co-morbidities | |||
| Alcohol abuse disorder | 64 (5.8%) | 693 (11.2%) | 0.489 (0.376–0.638), <0.001 |
| Anticoagulation | 57 (5.2%) | 405 (6.6%) | 0.780 (0.586–1.037), 0.086 |
| CHF | 39 (3.6%) | 237 (3.8%) | 0.922 (0.653–1.302), 0.646 |
| Cirrhosis | 43 (3.9%) | 116 (1.9%) | 2.128 (1.491–3.038), <0.001 |
| COPD | 47 (4.3%) | 420 (6.8%) | 0.612 (0.450–0.834), 0.002 |
| CVA | 11 (1%) | 131 (2.1%) | 0.467 (0.251–0.866), 0.013 |
| Dementia | 18 (1.6%) | 104 (1.7%) | 0.973 (0.587–1.611), 0.914 |
| Diabetes | 89 (8.1%) | 757 (12.3%) | 0.631 (0.502–0.794), <0.001 |
| HTN | 193 (17.6%) | 1,679 (27.2%) | 0.571 (0.484–0.673), 0.001 |
| Other | 153 (13.9%) | 915 (14.8%) | 0.930 (0.773–1.119), 0.443 |
| Psychiatric disorder | 85 (7.7%) | 854 (13.8%) | 0.523 (0.414–0.660), <0.001 |
| Renal dysfunction | 26 (2.4%) | 105 (1.7%) | 1.402 (0.908–2.164), 0.126 |
| Substance abuse | 59 (5.4%) | 724 (11.7%) | 0.427 (0.325–0.532), <0.001 |
| Chronic condition (any) | 670 (61.1%) | 4,441 (72%) | 0.610 (0.534–0.697), <0.001 |
| Mean CCI | 1.64 (±2.28) | 1.52 (±2.02) | 0.118 (–0.014 to 0.250), 0.081 |
| Trauma center characteristics | |||
| Level I trauma center | 766 (69.8%) | 4,165 (67.5%) | 1.112 (0.968–1.279), 0.141 |
| University teaching | 657 (59.9%) | 3,424 (55.5%) | <0.001 |
| Community teaching | 343 (31.3%) | 2,129 (34.6%) | |
| Non-teaching | 97 (8.8%) | 614 (10%) | |
| <200 beds | 66 (6%) | 353 (5.7%) | <0.001 |
| 201–400 beds | 282 (25.7%) | 1,731 (28.1%) | |
| 401–600 beds | 291 (26.5%) | 1,687 (27.4%) | |
| >600 beds | 458 (41.8%) | 2,396 (38.9%) | |
| Primary payor characteristics | |||
| Medicare/Medicaid | 396 (36.1%) | 2,793 (45.3%) | <0.001 |
| Private insurance | 362 (33%) | 2,204 (35.7%) | |
| Uninsured | 280 (25.5%) | 885 (14.4%) | |
| Other | 59 (5.4%) | 285 (4.6%) | |
On logistic regression (Table 4), admission GCS < 9, ISS > 15, age > 60 years, hypoxia, payor group, mechanism, and the presence of a TBI were independently associated with in-hospital death, but admission to a level I versus a level II center was not (1.009 [0.851-1.196]; p=0.918). The hourly risk of death, similarly, was not statistically significant with admission to a level I versus II center (Figure 2).
Table 4. Adjusted mortality outcomes for hypotensive trauma patients.
Other variables entered into forward stepwise regression: gender, race, CCI, hospital teaching type, hospital size
GCS Glasgow Coma Scale; ISS, Injury Severity Score; TBI, traumatic brain injury
| Variable | Exp(B) (95% CI for Exp(B)), p-value |
| Level I versus level II | 1.009 (0.851–1.196), 0.918 |
| GCS < 9 | 10.806 (9.019–12.947), <0.001 |
| ISS > 15 | 4.508 (3.638–5.590), <0.001 |
| Age > 60 years | 3.821 (3.142–4.646), <0.001 |
| Hypoxia (SpO2 < 93%) | 1.901 (1.596–2.264), <0.001 |
| Primary payor | 0.799 (0.729–0.876), <0.001 |
| Mechanism (E Code) | 1.44 (1.167–1.778), 0.001 |
| TBI any | 1.323 (1.110–1.577), 0.002 |
Figure 2. Hourly mortality for hemodynamically unstable trauma patients in a level I versus level II center.
Discussion
Literature is replete with studies addressing the outcome differences between level I and II trauma centers. Significant mortality increases at level II centers for specific subsets have been demonstrated. These include the severely injured [1,2], those with specific wounding [5], those with TBI [8,11], those transferred to a level II center after TBI [13], and overall populations [6,7]. Of specific interest to our study, those admitted with hemodynamic instability have been shown to have better mortality outcomes at a level I center that is sustained through early admission [2]. Of concern is that these reports may utilize obsolete data gathered prior to the 2014 “resources manual” update [12]. The previously mentioned study [2] on hypotensive trauma patients is an example of one of the more egregious confounding as it utilized data nearly over a decade old to support conclusions that were no longer valid at the time of publication.
The 2014 revision of the ACS-COT resources manual (Orange Book) specifically addresses clinical resourcing discrepancies between level I and II ACS-COT verified centers. “Level I and II criteria were revised to ensure that level I and II trauma centers are available to provide high quality definitive care” [12]. The assumption is that this would lead to reduction or elimination outcome discrepancies, though there are little data to support this. Our current investigation demonstrates this relative improvement and contradicts earlier reports. Furthermore, previous studies that demonstrate outcome equivalence or even improved outcomes at level II centers used locoregional data [8,14].
Our investigation shows no mortality difference between admission to a level I versus level II center in patients who present with hemodynamic instability. We hypothesize that this is associated with utilization of more contemporary datasets that were gathered after implementation of the 2014 ACS-COT “resources manual”. Updated requirements include, but are not limited to, uninterrupted emergency medicine staffing, more stringent operating room resourcing with performance tracking, defined minimums for highest level activations, minimum registrar training requirements, dedicated injury prevention positions, equivalent surgical and non-surgical subspecialty services, and changes in guidance for consultant bedside presence. One of the more pertinent improvements for both level I and II centers relate to performance improvement mandating exacting identification and trending of important outcome and process metrics. In addition, participation in a risk-adjusted outcome benchmarking program (Trauma Quality Improvement Program [TQIP]) was a significant new mandate [15]. Elements for a level I center, not required of a level II center, are admission volume minimums, the presence of higher level surgical resident trainees, a surgically directed intensive care unit, and minimum research productivity.
Despite a reasonably valid clinical association between improved resources and better outcomes, our study is hindered by its retrospective design. Trauma care at level II centers could have simply improved over time with the introduction of new techniques and protocols, though this is doubtful relative to outcome improvements related to mandated improved resourcing. While the 2017 TQP-PUF is a powerful tool to assess the impact of sweeping administrative mandates, it lacks the granularity to define elements that may have had an impact on our findings or that could have contributed to confounding. There were significant differences between level I and level II admissions. Most notably, level I admissions were more severely injured and differed demographically and by mechanism. Despite significant differences, adjusted mortality that included these variables was similar between level I and II centers and sustained hourly through the first 24 hours of admission. Of note, co-morbidities were not associated with death. This could possibly be due to survivors having more opportunity for their care teams to identify and document co-morbidities.
Applicability of our study extends only to ACS-COT verified centers regardless of the designating authority. While the scope of this organization is broad and many local designating authorities model their verification efforts to mirror the ACS-COT process and requirements, not all designated trauma centers are verified by this committee. It may be reasonable to assume that level II trauma centers verified by their local designating authority or other non-ACS-COT construct also experience improved outcomes relative to level I; however, our study excluded these trauma centers.
Despite these shortcomings, our study is impactful since it demonstrates, in contradiction to older published data, that level II trauma centers achieve similar outcomes in patients who present with hemodynamic instability compared to level I centers. In this subgroup, immediate presence of trauma surgeons, competent consultants, and timely availability of interventions are critical [15]. This change likely relates, in part, to the updated requirements that these elements be in place at a level II center just as they are at the level I center. Additionally, our study demonstrates the potentially significant and widespread beneficial impact of ongoing process improvement, resource standardization, and involvement of a national verification program. It is important for the public and policy-makers since it supports that the significant investment in a level II can be expected to generate outcomes similar to those at a level I center.
Conclusions
As opposed to previous studies, level II trauma centers perform similar to level I centers for trauma patients who present with hemodynamic instability. This may relate to compliance with the ACS-COT resources manual, Resources for the Optimal Care of the Injured Patient, 2014 version. Further study would include examination of trauma centers that are not verified by the ACS-COT that could reveal more specific variables associated with improved outcome in these patients.
The content published in Cureus is the result of clinical experience and/or research by independent individuals or organizations. Cureus is not responsible for the scientific accuracy or reliability of data or conclusions published herein. All content published within Cureus is intended only for educational, research and reference purposes. Additionally, articles published within Cureus should not be deemed a suitable substitute for the advice of a qualified health care professional. Do not disregard or avoid professional medical advice due to content published within Cureus.
The authors have declared that no competing interests exist.
Human Ethics
Consent was obtained or waived by all participants in this study
Animal Ethics
Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue.
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