Fluid resuscitation after severe trauma injury : U-shaped associations between tetrastarch dose and survival time or frequency of acute kidney failure

BACKGROUND

Using tetrastarch for fluid resuscitation after a severe trauma injury may increase risks of death and acute kidney injury. The importance of tetrastarch dose, however, is unknown.

METHODS

A retrospective observational study was performed in two trauma centres using data on type and amount of fluids (balanced crystalloids or tetrastarch) used for pre- and acute in-hospital shock management. We evaluate independent associations between the relative and absolute volumes of tetrastarch and 90-day survival time or the frequency of severe acute kidney failure (AKF).

RESULTS

We studied 271 patients who had sustained a severe blunt trauma injury (average predicted mortality according to the Revised Injury Severity Classification Score (RISC) 15.1 ± 1.4% [mean, standard deviation]), and who had required more than 2 days of intensive care therapy. In all, 75.3% of patients had received tetrastarch with a crystalloid/colloid ratio of 2.93 ± 2.60. The 90-day mortality was 11.1%, and 7.8% of the patients developed severe AKF. After adjusting for confounders, we found a U-shaped, nonlinear association between absolute or relative volumes of tetrastarch and survival time (p = 0.003 and 0.025, respectively). Optimal relative volumes of tetrastarch approximately ranged from 20 to 30% of total fluids. Giving less than about 1000 ml, or more than about 2000 ml tetrastarch was significantly associated with an increased risk of developing severe AKF (p = 0.023).

CONCLUSIONS

There was a complex U‑shaped association between the tetrastarch dose and morbidity/mortality of patients after a severe trauma injury. The optimal crystalloid/tetrastarch ratio for acute shock management appears to range from about 2.5 to 4.0.

Long-term changes of patient-reported quality of life after major trauma: The importance of the time elapsed after injury

BACKGROUND

Numerous studies have identified various risk factors for a poor health-related quality of life (HRQOL) after severe trauma. The relative importance of the time elapsed after injury, however, is unknown and results of clinical studies have been conflicting.

METHODS

A cross-sectional study was performed in two trauma centres using data from the German TraumaRegister DGU^®, which contained prospectively collected information on the type and severity of the injury, on critical care, and on outcome. To evaluate HRQOL in patients surviving more than 500days after the injury, we used a self-rating instrument, the EQ-5D which contains a visual analogue scale (EQ-VAS), and which allows the calculation of a global outcome indicator, the EQ-D5 index value. Complex statistical models were used to evaluate independent associations between the time elapsed after injury and a poor HRQOL.

RESULTS

Of 380 contacted patients, follow-up assessments could be obtained in 168 patients (44.2%) 3.6±1.6 (SD) years after the injury. There was a linear association between the time elapsed after the injury and the% of contacted patients not participating in the study (p=0.013). In participating subjects, average EQ-5D index value was 0.599±0.299, and average EQ-VAS rating 67.8±22.0. A very poor quality of life (EQ-5D index value<0.6, EQ-VAS rating≤50) could be found in 43.5% and 28.0% of the patients, respectively. After adjusting for multiple confounders, the number of days elapsed after injury showed a complex non-linear and independent association with a poor HRQOL (low EQ-5D index value: p=0.027; low EQ-VAS rating: p=0.008). Frequencies of a poor HRQOL reached their minimum about four to five years after the injury and increased thereafter.

CONCLUSIONS

There is an independent, U-shaped association between the frequency of extreme values of HRQOL and the time elapsed after injury. Time patterns of HRQOL may be sensitive to increasing rates of attrition since patients with a good outcome are less likely to respond to questionnaires. Time from injury should be incorporated into all future cross sectional studies trying to identify predictors of HRQOL.