Applying Sports Concussion Assessment Tools to Pre-Hospital EMS Screening of Head Injuries during Defensive Tactics Training

Alan E. Perry 5/9/2013

City of Chesapeake Fire Department

Abstract

This study examines the usefulness of the Sports Concussion Assessment Tool 2 (SCAT2) as an effective means of predicting the presence of closed head injury in the pre-hospital environment by paramedics with training in the use of the tool. It specifically examines a controlled group of police officer candidates during defensive tactics training evolutions, a group known to occasionally suffer both minor and severe head injury during the course of that training. By comparing baseline test score of the candidates to scores obtained during physical and emotional stress, some anticipated limitations of both the tool and local EMS protocol where confirmed.

Acknowledgments

This study could not have been accomplished without the cooperation of the Officers, Training Staff and Officer Candidates of the Chesapeake Police Department. Their cooperation and interest in the study was absolutely essential to achieving any meaningful outcome. My fellow Officers and Paramedics, who shared in developing and performing this study; Kevin Tam, Christopher Hudspeth, David Rose and Doctor Martin Payne, all provided meaningful input into the design and execution of this study. Doctor Heidi Kulberg, Deputy Director of the Chesapeake Health Department, who introduced and trained the medics in the use of the SCAT2 tool. She selected this tool to address the need for evaluating this type of injury, and reducing injuries among employees participating in Defensive Tactics Training. She provided regular and valuable input throughout the process, and supported this study.

Applying Sports Concussion Assessment Tools to Pre-Hospital EMS Screening of Head Injuries during Defensive Tactics Training

Background

Traumatic brain injury has been a source of concern in sports injury and in combat related incidents involving explosives. Recent tragic events in Norfolk, Virginia involving police recruits during defensive Tactics training, established a clear need for some means to screen for closed head injury (CHI), educate training staff and students, and develop a return to play (RTP) protocol in this setting.

The City of Chesapeake, through the Chesapeake Health Department, sought to minimize the risk involved with this type of training by enlisting the aid of paramedics already assigned to the Police Departments Special Weapons and Tactics team. Medics where selected to monitor these events, evaluate those suspected of having received a CHI, and remove them from the exercise if indicated to avoid more serious injury.

Doctor Kulberg introduced the SCAT2 assessment tool (McCrory, 2008), trained the medics on its application, and walked us through the baseline screening process for all of the Officer Candidates in the test group. It is important to note that prior to the introduction of the SCAT2, regional EMS protocols (Tidewater Emergency Medical Services, Inc., 2010) were the only guideline for medics to follow for head injury. This protocol did not address the less dramatic presentations that could indicate a potential CHI. While the protocol does address more significant events, such as altered mental status, unconsciousness and seizure, it is not adequate for ruling out the presence of CHI, or offer guidance for removing participants from the activity to prevent further injury.

Setting

The SCAT2 is a comprehensive exam which includes subjective and objective data, evaluating symptoms reported by the subject, Glasgow coma scale, cognitive assessment, balance and coordination. A shorter version is applied as a sideline tool, which seems applicable for our purposes. The “Pocket SCAT2” (PSCAT2) is less involved and is condensed to reported symptoms, memory function and balance. It was noted by both Doctor Kulberg, and the paramedics, that the full SCAT2 was very sensitive and should prove useful if performed consistently in controlled environments.

Application of the tools included performing a full SCAT2 on each candidate in a rested state, in a controlled and consistent environment, thereby establishing a good baseline assessment for each. In the event of a suspected head injury, i.e. getting hit in the head, blacking out, becoming disoriented; the participant would immediately be removed from activity, and have a rapid exam using the PSCAT2. Any significant deficit would result in a transport to the Hospital Emergency Department(ED) for evaluation. Minor changes would result in the participant being sidelined, and observed until symptoms resolved, if no resolution occurred they would also be transported to the ED. All events requiring any evaluation by an Ed physician would result in a full SCAT2 being performed by Doctor Kulberg before the participant would be allowed to return to training.

Given the level of sensitivity that the SCAT2 appeared to provide, the incidence of false positives arose in several discussions among those administering the test. While the value of the tool in making more informed clinical judgment decisions was not disputed, the concern of over-treating, or removing from activity for a test variation not attributable to a head injury, was a concern. The SCAT2 does not provide guidance on acceptable test score variation, or define at what point a score is positive for a head injury. Specific symptoms are considered highly suspicious by SCAT2, PSCAT2, and local EMS protocol.

Hypothesis and Questions

There was concern that there may be normal variations in SCAT2 scores caused by factors not related to head injury, such as fatigue, level of exertion, climate, environment, and any number of other external variables that will be unavoidable when conducting this evaluation in the field. To determine if, and to what extent, this may be true the following questions were posed.

1. What level, and types of variation, should be expected and considered normal?

2. Are there certain areas, or specific scores, that will be more affected than others?

3. Can this tool be applied to pre-hospital EMS reliably?

4. If variations are present, do these variations affect the usefulness of the SCAT2 tool?

Study Organization and Methods

Baseline SCAT2 scores were obtained on all officer candidates attending the Defensive Tactics course in a controlled environment. The pool of subjects that completed the evaluation ranged in age from 22 years to 41 years, two females, and five males, three of the seven subjects had a previous history of head injury. SCAT2 scores were placed in each candidates training file for access during the course by paramedics. Any candidate who actually suffered a head injury during the course, or was otherwise removed from the course, was excluded from the study.

Subjects were evaluated on the final day of Defensive Tactics, the most physically demanding portion when candidates must successfully defend themselves from multiple assailants. The candidate was escorted from the exercise and given the PSCAT2 within five minutes. A second exam was given at one hour. These evaluations were not performed in the same environment as the baseline exam because that was not possible, however all subjects were evaluated by the same person, in exactly the same way. Test results were compiled and compared to their baseline SCAT2 scores to determine what variations exist.

Results

All subjects exhibited a decline from their baseline scores immediately following the defensive tactics exercise, with the most commonly reported symptom being fatigue, followed by balance and orientation score(time of day) deficits. Most subjects returned to their baseline within 1 hour, none had more than one remaining deficit and several actually improved from their baseline assessment values. No significant variations were evident between age groups, sexes, or those who had previous head injury.

Limitations of the study

The value of this study is limited since the number of final subjects is few and it is based on only one scenario. Since the purpose of the study was only to determine if there may be some normal variations, and in what areas these might occur, the data still appeared to be useful. Additional study seems to be indicated to establish thresholds in the scoring matrix that reflect a point at which to transition from observation to treatment.

Conclusions

The observed decline in scores seems easily attributable to the muscle fatigue immediately following such an exercise, and not associated with a head injury. The physical and mental state of the subject appears to have a measurable effect on their test score as well. The return to baseline for the majority of the subjects validates the approach of the SCAT2 system of monitoring of minor symptoms for improvement, and only taking action if they worsen or do not resolve. The results suggest that minor deviations from the baseline SCAT2 score are to be expected immediately following physically demanding, or emotionally stressful events. The results do not lessen the value of the tool for predicting head injury when performed serially over a longer term, and in controlled environments. The development of a more detailed neurological assessment for pre-hospital use appears to be warranted since many of the criteria of the SCAT2 do not appear in EMS protocol decision points. Existing protocol would fail to detect and properly treat patients suffering from less severe traumatic brain injuries that could easily worsen with continued activity. A protocol adapting the criteria of the PSCAT2 and current EMS protocol could satisfy that need (see appendix A). As with any patient assessment tool, it is only a tool; the good judgment of the provider must also be incorporated into any decision and treatment plan, always erring on the side of patient safety.