May 2023 - Trauma

May 2023
EAST Monthly Literature Review


"Keeping You Up-to-Date with Current Literature"
Brought to you by the EAST Manuscript and Literature Review Committee



This issue was prepared by EAST Military Committee Member Joshua Corsa, MD and EAST Educational Resources Committee Member Shyam Murali, MD.


Thank you to Haemonetics for supporting the EAST Monthly Literature Review.


In This Issue: Trauma 

Scroll down to see summaries of these articles

Article 1 reviewed by Joshua Corsa, MD
The role of prehospital ultrasound in reducing time to definitive care in abdominal trauma patients with moderate to severe liver and spleen injuries. Gamberini L, Tartaglione M, Giugni A, et al. Injury. 2022 May;53(5):1587-1595.

Article 2 reviewed by Joshua Corsa, MD
Prehospital Lactate is Associated with the Need for Blood in Trauma. Zadorozny EV, Weigel T, Stone A, et al. Prehosp Emerg Care. 2022 Jul-Aug;26(4):590-599.

Article 3 reviewed by Shyam Murali, MD
Prehospital end-tidal carbon dioxide is predictive of death and massive transfusion in injured patients: An Eastern Association for Surgery of Trauma multicenter trial. Campion EM, Cralley A, Sauaia A, et al. J Trauma Acute Care Surg. 2022 Feb 1;92(2):355-361.

Article 4 reviewed by Shyam Murali, MD
AAST multicenter prospective analysis of prehospital tourniquet use for extremity trauma. Schroll R, Smith A, Alabaster K, Schroeppel TJ, Stillman ZE, Teicher EJ, Lita E, et al. J Trauma Acute Care Surg. 2022 Jun 1;92(6):997-1004.

Article 1
The role of prehospital ultrasound in reducing time to definitive care in abdominal trauma patients with moderate to severe liver and spleen injuries. Gamberini L, Tartaglione M, Giugni A, et al. Injury. 2022 May;53(5):1587-1595.

Ultrasonography has been demonstrated to be a rapid and reliable imaging modality in critically ill trauma patients. As the technology improves, ultrasound device size and durability has improved to the point where battlefield and prehospital use by both paramedics and physicians is fast becoming routine. Dr. Gamberini and colleagues recently published their work evaluating prehospital FAST exams and their effect on time to definitive care in both moderate to severe liver and spleen injuries.
 
The study included patients with an Abdominal Abbreviated Injury Score ≥ 2 and a liver or spleen injury. It then compared those in whom a prehospital FAST was not performed to those in whom a prehospital FAST exam was performed. In the trauma system studied, a positive prehospital FAST Exam triggered a massive transfusion protocol, an open OR, and the ability to bypass the ED and transfer the patient straight from the ambulance to the OR if needed.

The study included 199 patients admitted to the level one trauma center between 2014 and 2019. Prehospital FAST exams were performed in 44 patients, with 27 positive prehospital FAST exams. Of the 199 total studied patients, 128 had positive FAST exams in the ED, for a prehospital FAST sensitivity of 62.9% and specificity of 100%. Of the patients with a positive prehospital FAST, a significantly lower door to CT or door to OR time was reported at 46 vs 69 min. Similarly, 60% of patients with a positive prehospital FAST arrived in the CT or OR in 60 minutes, whereas the cohort without a prehospital FAST reached the 60% threshold at 75 minutes.
 
After adjusting for variables including prehospital hypotension, ISS, GCS, and age, only ISS and a positive prehospital FAST resulted in a significance decrease in door to CT or door to OR time. Of note, those patients with a positive prehospital FAST had a higher ISS and lower SBP & MAP and were significantly more likely to taken directly to the OR (41% vs 8%).

This study, conducted in Italy, evaluated physician performed FAST exams. This limits its applicability to the American system, where prehospital evaluation and interventions are performed by paramedics the vast majority of the time. Other research, however, has demonstrated the ability of paramedics to obtain adequate ultrasonographic images in the prehospital environment. Additionally, FAST exams where only performed on 25% of the patients studied, indicating that there is still work to be done regarding its broader use and acceptance in the prehospital environment. As the field advances, paramedic-performed FAST exams, with physician review via telemedicine, may also be able to decrease time from injury to OR and improve outcomes.   
 
Article 2
Prehospital Lactate is Associated with the Need for Blood in Trauma. Zadorozny EV, Weigel T, Stone A, et al. Prehosp Emerg Care. 2022 Jul-Aug;26(4):590-599.

There is currently a dearth of reliable predictors of the need for blood transfusion in trauma patients. While hypotension, shock index, and other physiologic metrics can predict the need for transfusion in critically ill patients, they can fail to predict transfusion requirements in hemodynamically normal patients. EtCO2 and prehospital venous lactate levels are being investigated as possible objective predictors of transfusion and have offered promising initial results. In this study, Dr. Zadorozny and colleagues investigated whether prehospital venous lactate measurements were associated with the need for blood transfusion in the first 24hr of admission in trauma patients.
 
The team evaluated 2,170 trauma patients transported by EMS from either outlying hospitals or the point of injury. A venous lactate sample was obtained by EMS personnel on all patients while enroute to the trauma center. The overall rate of blood transfusion was 17%, with 37% of patients needed a lifesaving intervention without the first 24 hrs. of admission. The median prehospital lactate for subjects who received blood products within the first 24 hrs. of admission was 3.05 mmol/L, and for those who did not receive blood products the median lactate was 1.98 mmol/L. An increase in prehospital venous lactate of 1 mmol/L was associated with a 12% increase in the odds of needing blood products within the first 24 hrs. of admission in both the normotensive and hypotensive (SBP < 90) cohorts (OR = 1.12, (95% CI 1.06-1.20). An increase in prehospital lactate levels was also associated with the need for in-hospital lifesaving interventions in the first 24 hrs. and higher odds of mortality (OR=1.32, (95% CI 1.20-1.45).

Existing prehospital literature regarding lactate measurements is mainly limited to hypotensive patients or patients requiring prehospital blood transfusions. This study adds to that body of work by demonstrating that elevated prehospital lactate levels can be predictive of blood transfusion needs in normotensive patients as well. The deployment of prehospital lactate monitoring is currently limited by cost, regulatory, and technologic constraints. As new durable and affordable meters are developed, the utility and utilization of prehospital lactate measurements will likely continue to grow.

Article 3
Prehospital end-tidal carbon dioxide is predictive of death and massive transfusion in injured patients: An Eastern Association for Surgery of Trauma multicenter trial. Campion EM, Cralley A, Sauaia A, et al. J Trauma Acute Care Surg. 2022 Feb 1;92(2):355-361.

Identification of critically ill trauma patients is an imperative skill for the prehospital provider as it can influence treatment decisions, as well as impact transportation logistics. To aid in this process, end-tidal carbon dioxide (ETCO2) has been proposed as a marker of poor perfusion and impaired alveolar gas exchange, indicating a severe hemorrhagic shock state. The investigators of this trial performed a retrospective multicenter study of 24 trauma centers; patients were eligible if they were transported by EMS between January 2017 to December 2018, had a prehospital intubation, and had ETCO2 measured at least once during transport. Interfacility transports, children younger than 15 years, and prisoners were excluded from the study. Over the 2-year period, 1,324 patients were included in their analysis with a median age of 41 years, 20.1% penetrating injury rate, with 30.4% experiencing prehospital CPR. The mean ISS was 25 and overall mortality was 47.7%. While prehospital ETCO2 performed better at predicting mortality than SBP and shock index, its AUROC was only 0.67 (CI 0.63-0.71). All three variables were equally predictive of massive transfusion (defined as >10 units of pRBC in 6 hours or death in the first 6 hours after receiving at least 1 unit of blood). In a subgroup analysis of patients that were normotensive, AUROC was 0.66 (0.61-0.71) and outperformed lowest SBP and highest shock index; the ETCO2 cutoff value as determined by Youden index was 31 mmHg for mortality and 26 mmHg for massive transfusion.

The data obtained from this study is consistent with previous prehospital literature in trauma, which shows an inverse correlation of ETCO2 and mortality. The obvious strengths of this study are the large number of subjects and multicenter nature, which aids in generalizability. However, the limitations include a retrospective nature that could introduce bias, lack of specific causes of death, and no standardization of which patients had ETCO2 measured (this was guided by local EMS agency protocols). Furthermore, it is difficult to extrapolate these findings to patients that were not intubated. However, this study certainly demonstrates that further research should be conducted to better elucidate the role of ETCO2 in the prehospital care of trauma patients.

Article 4
AAST multicenter prospective analysis of prehospital tourniquet use for extremity trauma. Schroll R, Smith A, Alabaster K, Schroeppel TJ, Stillman ZE, Teicher EJ, Lita E, et al. J Trauma Acute Care Surg. 2022 Jun 1;92(6):997-1004.

Civilian and EMS use of tourniquets for major extremity trauma (MET) has increased significantly over the past decade with the development of courses such as Stop the Bleed. While tourniquet use may intuitively make sense, thus far all civilian studies have been retrospective, single center, or lacking control groups. This AAST multicenter study prospectively assessed whether prehospital tourniquet use would decrease the incidence of shock on arrival to a trauma center. Investigators assessed whether the incidence of shock (defined as SBP≤90mmHg) on arrival to a trauma center was lower in patients who had a prehospital tourniquet placed compared to patients who did not. The control group consisted of patients who did not have a prehospital tourniquet placed but needed one based on the treating physicians’ discretion. Of note, limbs with noncommercial/improvised tourniquets were also placed in the control group.

Prehospital tourniquets were placed on 962 limbs, while 350 limbs were enrolled in the control group (tourniquet placed on arrival with either a prehospital noncommercial tourniquet or no prehospital tourniquet). The investigators found that, despite higher limb injury severity, patients in the prehospital tourniquet group were less likely to arrive in shock (13.0%) compared with the control group (17.4%) (p=0.04). There was no difference for in-hospital mortality, but the time to death was shorter in the control group. However, the incidence of amputation was higher in the prehospital tourniquet group (10.7%) compared to control (5.7%) (p<0.01). In patients who had a documented major vascular injury, prehospital tourniquet use was, again, associated with a lower incidence of arrival to the trauma center in shock. On multivariate analysis, patients arriving without a tourniquet had a threefold risk of being in shock (OR, 3.1; 95% CI, 1.7–5.8; p < 0.001).

This large study provides us with much needed multicenter data and incorporates regional variations in practice patterns to improve external validity. There were some notable differences in characteristics of the study population. While ISS was similar between groups, the AIS and Mangled Extremity Severity Score (MESS) of the injured extremity were higher in the prehospital tourniquet group, as were the rates of TBI and other associated injuries. Despite this difference, the tourniquet group had mortality rates and blood product transfusions similar to the control group, raising the possibility that tourniquets play some role in mitigating death. Rates of GSW and blunt or crush mechanisms were higher in the tourniquet group, while stab wounds were more common in the control group. The study was slightly underpowered based on a priori calculation of power analysis and there was significant variation in the number of patients enrolled at each site, which could introduce some bias. Finally, selection bias could have been introduced by the treating trauma surgeon who subjectively assessed the need for tourniquet at the receiving hospital. Overall, this study certainly confirms the current general sentiment of tourniquet effectiveness. With the rise in gun violence, tourniquets will be crucial to in treating massive hemorrhage due to MET.


Have you checked out EAST's Landmark Paper Resource?
Mark Your Calendar for the 37th EAST Annual Scientific Assembly 
January 9-13, 2024 at the Signia by Hilton Bonnet Creek in Orlando Florida.

It's Membership Renewal Time - Sign in to your Profile to check
your renewal status and pay your 2023 dues. 
 
 This Literature Review is being brought to you by the EAST Manuscript and Literature Review Committee. Have a suggestion for a review or an additional comment on articles reviewed? Please email litreview@east.org.
Previous issues available on the EAST website.