Trimodal temporal distribution of fatal trauma--fact or fiction?

The distribution of survival times after injury

INTRODUCTION

The distribution of survival times after injury has been described as "trimodal," but several studies have not confirmed this. The purpose of this study was to clarify the distribution of survival times after injury.

METHODS

We defined survival time (t(s)) as the interval between injury time and declared death time. We constructed histograms for t(s) ≤ 150 min from the 2004-2007 Fatality Analysis Reporting System (FARS, for traffic crashes) and National Violent Death Reporting System (NVDRS, for homicides). We estimated statistical models in which death times known only within intervals were treated as interval-censored. For confirmation, we also obtained EMS response times (t(r)), prehospital times (t(p)), and hospital times (t(h)) for decedents in the 2008 National Trauma Data Bank (NTDB) with t(s) = t(p) + t(h) ≤ 150. We approximated times until circulatory arrest (t(x)) as t(r) for patients pulseless at the injury scene, t(p) for other patients pulseless at hospital admission, and t(s) for the rest; for any declared t(s), we calculated mean t(x)/t(s). We used this ratio to estimate t(x) for hospital deaths in FARS or NVDRS and provide independent support for using interval-censored methods.

RESULTS

FARS and NVDRS deaths were most frequent in the first few minutes. Both showed a second peak at 35-40 min after injury, corresponding to peaks in hospital deaths. Third peaks were not present. Estimated t(x) in FARS and NVDRS did not show second peaks and were similar to estimates treating some death times as interval-censored.

CONCLUSIONS

Increases in frequency of survival times at 35-40 min are primarily artifacts created because declaration of death in hospitals is delayed until completing resuscitative attempts. By avoiding these artifacts, interval censoring methods are useful for analysis of injury survival times.

Temporal Patterns of Death after Trauma: Evaluation of Circadian, Diurnal, Periodical and Seasonal Trends in 260 Fatal Injuries

Background:

Temporal patterns of trauma deaths may indicate potential for prevention or systems improvement, but have been poorly investigated in the Scandinavian trauma population. This study examines patterns in trauma deaths to the occurrence in hour and time of the day, day and time in the week, and month and season.

Materials and Methods:

Investigation of the temporal patterns of death in 260 fatalities undergoing autopsy. Time of death were explored according to time of the day (hour; day/night), time of the week (day of week; weekday/weekend) and time of the year (month; season) and analyzed for difference in gender, age, injury type and severity, and mechanisms of injury and death.

Results:

A total of 260 trauma deaths were included, of which 125 (48%) died in hospital and 194 (75%) were male. No particular peak-hour of the day when deaths occurred was found. One-third of deaths occurred during weekends. For inhospital deaths during weekends, significantly more patients had respiratory distress (RR > 20 or < 16 in 72.5% for weekends and 47.0% for weekdays; p = 0.008) and hypotension (SBP < 90mmHg in 61% vs 40%; p = 0.048) during weekends. Deaths occurred with some monthly variance demonstrated with two monthly peaks in February/March and July/August, respectively. Overall, no statistically different seasonal differences in the occurrence of traumatic deaths, nor any differences in cause of death, type or severity of injury, nor in physiological parameters was found. However, a higher number of inhospital deaths presented with reduced consciousness level (GCS < 8) and severe head injuries (AIS-head ≥ 4) during spring and summer (P = 0.045, chi-square for trend) compared to winter and fall.

Conclusions:

Trauma deaths in a Scandinavian population did not demonstrate statistically significant differences in overall circadian, weekly or seasonal patterns of trauma death occurrence. However, the impact of fatal head injuries during spring and summer warrants further investigation.

Trauma systems and early management of severe injuries in Scandinavia: review of the current state

INTRODUCTION

Scandinavian countries face common challenges in trauma care. It has been suggested that Scandinavian trauma system development is immature compared to that of other regions. We wanted to assess the current status of Scandinavian trauma management and system development.

METHODS

An extensive search of the Medline/Pubmed, EMBASE and SweMed+ databases was conducted. Wide coverage was prioritized over systematic search strategies. Scandinavian publications from the last decade pertaining to trauma epidemiology, trauma systems and early trauma management were included.

RESULTS

The incidence of severe injury ranged from 30 to 52 per 100,000 inhabitants annually, with about 90% due to blunt trauma. Parts of Scandinavia are sparsely populated with long pre-hospital distances. In accordance with other European countries, pre-hospital physicians are widely employed and studies indicate that this practice imparts a survival benefit to trauma patients. More than 200 Scandinavian hospitals receive injured patients, increasingly via multidisciplinary trauma teams. Challenges remain concerning pre-hospital identification of the severely injured. Improved triage allows for a better match between patient needs and the level of resources available. Trauma management is threatened by the increasing sub-specialisation of professions and institutions. Scandinavian research is leading the development of team- and simulation-based trauma training. Several pan-Scandinavian efforts have facilitated research and provided guidelines for clinical management.

CONCLUSION

Scandinavian trauma research is characterised by an active collaboration across countries. The current challenges require a focus on the role of traumatology within an increasingly fragmented health care system. Regional networks of predictable and accountable pre- and in-hospital resources are needed for efficient trauma systems. Successful development requires both novel research and scientific assessment of imported principles of trauma care.

Damage control orthopaedics: lessons learned

Damage control orthopaedics (DCO) is a staged approach for the management of multiply injured patients. It is ideal for trauma patients presenting in an unstable or extremis physiological state. It focuses on the rapid resuscitation of these patients by providing temporary stabilisation of fractures while at the same time reducing the biological load of surgery. Early findings support its usefulness in controlling the lethal triad of hypothermia, acidosis and coagulopathy. Furthermore, recent evidence indicates that it regulates the evolving systemic inflammatory response, reducing the detrimental complications of adult respiratory distress syndrome, multiple organ dysfunction and subsequent mortality. Although DCO has been proven a useful surgical strategy for efficiently managing patients with multiple trauma, further work is required to establish fully its indications, results and cost implications.

An analysis of in-hospital deaths at a modern combat support hospital

BACKGROUND

Analysis of the epidemiology and attribution of in-hospital deaths is a critical component of learning and process improvement for any trauma center. We sought to perform a detailed analysis of in-hospital deaths at a combat support hospital.

METHODS

All patients with trauma who survived to admission and subsequently died before transfer or discharge during a 1-year period were included. The timing, location, pathogenesis, and circumstances surrounding the death were recorded. Opportunities for improvement (OI) of care were identified for analysis. Cases were presented to a panel of experts, and preventability of the deaths was scored on a continuous 10-point scale.

RESULTS

There were 151 deaths, with the predominant mechanisms of gunshot wounds (GSW) (47%) and blast injuries (42%). Most had severe injuries, with a mean Injury Severity Score of 38, pH of 7.09, and base deficit of 12. Predominant causes of death were head injury (45%) and hemorrhage (32%), and 78% died within 1 hour of admission. Most deaths occurred during the intensive care (35%) or resuscitation phases (31%), but the majority of deaths among nonexpectant patients occurred during the operative phase (38%). OI were identified in 74 deaths (49%), and were found in 78% of nonexpectant deaths. Most improvement opportunities occurred during the resuscitation and transport phases. Most potential improvements were identified at the system level (54%) or individual provider level (42%). Preventability scoring showed excellent inter-rater reliability (r = 0.92, p < 0.001). Deaths with high preventability scores (mean >54) were primarily related to delays in hemorrhage control during the transportation (47%) or resuscitation (43%) phases, and attributed to the system (63%) and individual provider levels (70%).

CONCLUSIONS

In-hospital combat trauma-related deaths at a modern Combat support hospital differ significantly from their civilian counterparts, and present multiple OI of care and potential salvage. Delays in prehospital and in-hospital hemorrhage control are the primary contributors to potential preventability.