Page 71 - JSOM Summer 2018

FIGURE 10 Electroencephalography-determined workload relative FIGURE 11 Heart rate variability.
to errors (weeks 2–6).

Although this metric varied widely between individuals, the
techs had a higher mean HRV. In addition, there was a trend
among the surgeons and the techs toward HRV suppression in
the motion conditions. trend toward HRV suppression within the motion conditions
for surgeons and techs may indicate a coping response to the
TLX scores were sensitive to the sea state (main effect p < increased stress and arousal of the motion setting.
.001), but the effect of sea state varied across members of the
surgical team according to positions. The within-subjects sea That motion did not significantly influence overall surgical
state by role interaction term was significant (p < .001). Proce- performance but that there was a significant effect of the sur-
dure type had no detectable effect. gical performance compared with surgical team and proce-
dure type are key findings because they address the concern of
To determine the effect of workload (determined by mea- potential limitations to a professional’s ability to perform on
sured EEG and self-reported TLX) may have had on overall nontraditional platforms. Given that there were no significant
performance, nonparametric ordinal logistic regression was findings to suggest movement affects performance, additional
performed on performance scores as determined by the SME research should focus on maximizing team unity and proce-
postoperative assessment against workload metrics. Neither dure familiarity. Other researchers have argued that improv-
EEG-based nor TLX-determined workload was a significant ing survivability on the battlefield is directly related to several
predictor of performance. In addition, no significant correla- factors, one being research and development with an added
tion was determined between the workload and the rate at emphasis on training and leadership. 10
which severe errors were committed.
Limitations to this study include only performing one proce-
Role and Motion Condition dure at a time, the design of the simulator with respect to the
A significant interaction was present for role versus motion actual speeds/movements of vessels, and group assignment.
condition (p = .002), in which workload decreased slightly for Surgical procedure demonstrated the strongest predictor of
the surgeons in the motion conditions versus the no-motion performance. Including multiple procedures performed si-
condition, but increased for the techs in the motion conditions. multaneously, much like what would be encountered in a true
Overall, the surgeons had consistently higher workload than trauma situation, could alter these results. Although the de-
the techs, but neither group exhibited considerable differences sign of the simulator represented high-sea vessels, without per-
between the motion versus no-motion conditions. forming the experiment on actual Navy ships, the simulator
may not accurately represent movements encountered while
Discussion at sea. Finally, group assignment could explain why one surgi-
cal team performed at a statistically lower level that the other
We attribute the role versus motion findings to the nature groups. This could be accounted for by the group having a
of each individual’s job during surgery, with surgeons hav- unique learning curve, a possible acclimation process within
ing more workloads overall because they perform most of the study, and various levels of individual expertise within the
the critical thinking and physical execution of procedures. In groups.
addition, surgeons have more expertise and years of surgical
experience than do techs, which possibly contributed to their Procedure and team dynamic were the strongest predictors of
decreased workloads during motion when compared with the overall performance in this study, and increased attempts im-
techs’ increased workloads during motion. proved blood packing effectiveness. These findings suggest a
learning curve exists and added focus in training could greatly
TLX scores were also consistently higher than measured EEG- benefit our Servicemembers and the communities to which
based workload, suggesting that surgeons perceived their they provide care.
workload to be higher overall than others on the surgical team
in the motion conditions, because they were doing the critical
thinking and decision-making. Additional participants should Conclusion
be added to verify this trend. Based on data collected in this study, similar surgical proce-
dures should be implemented aboard these classes of ship with
The HRV versus motion condition did not have a significant comparable sea states. In doing so, injured military person-
effect. This factor varied widely between individuals, but the nel would have more timely access to care, and devastating

The Effect of High Deck Accelerations on Surgical Tasks | 69