Real-time assessment of hepatic function is related to clinical outcome in critically ill patients after polytrauma

Global changes in mortality rates in polytrauma patients admitted to the ICU-a systematic review

Background

Many factors of trauma care have changed in the last decades. This review investigated the effect of these changes on global all-cause and cause-specific mortality in polytrauma patients admitted to the intensive care unit (ICU). Moreover, changes in trauma mechanism over time and differences between continents were analyzed.

Main body

A systematic review of literature on all-cause mortality in polytrauma patients admitted to ICU was conducted. All-cause and cause-specific mortality rates were extracted as well as trauma mechanism of each patient. Poisson regression analysis was used to model time trends in all-cause and cause-specific mortality.

Thirty studies, which reported mortality rates for 82,272 patients, were included and showed a decrease of 1.8% (95% CI 1.6–2.0%) in all-cause mortality per year since 1966. The relative contribution of brain injury-related death has increased over the years, whereas the relative contribution of death due to multiple organ dysfunction syndrome (MODS), acute respiratory distress syndrome, and sepsis decreased. MODS was the most common cause of death in North America, and brain-related death was the most common in Asia, South America, and Europe. Penetrating trauma was most often reported in North America and Asia.

Conclusions

All-cause mortality in polytrauma patients admitted to the ICU has decreased over the last decades. A shift from MODS to brain-related death was observed. Geographical differences in cause-specific mortality were present, which may provide region-specific learning possibilities resulting in improvement of global trauma care.

Predictive value of cytokines for developing complications after polytrauma

AIM: To investigate posttraumatic cytokine alterations and their value for predicting complications and mortality in polytraumatized patients.

METHODS: Studies on the use of specific cytokines to predict the development of complications and mortality were identified in MEDLINE, EMBASE, Web of Science and the Cochrane Library. Of included studies, relevant data were extracted and study quality was scored.

RESULTS: Forty-two studies published between 1988 and 2015 were identified, including 28 cohort studies and 14 “nested” case-control studies. Most studies investigated the cytokines interleukin (IL)-6, IL-8, IL-10 and tumor necrosis factor (TNF-α). IL-6 seems related to muliorgan dysfunction syndrome, multiorgan failure (MOF) and mortality; IL-8 appears altered in acute respiratory distress syndrome, MOF and mortality; IL-10 alterations seem to precede sepsis and MOF; and TNF-α seems related to MOF.

CONCLUSION: Cytokine secretion patterns appear to be different for patients developing complications when compared to patients with uneventful posttraumatic course. More research is needed to strengthen the evidence for clinical relevance of these cytokines.

Impact of hypoxic hepatitis on mortality in the intensive care unit

PURPOSE

Hypoxic hepatitis (HH) is a form of hepatic injury following arterial hypoxemia, ischemia, and passive congestion of the liver. We investigated the incidence and the prognostic implications of HH in the medical intensive care unit (ICU).

METHODS

A total of 1,066 consecutive ICU admissions at three medical ICUs of a university hospital were included in this prospective cohort study. All patients were screened prospectively for the presence of HH according to established criteria. Independent risk factors of mortality in this cohort of critically ill patients were identified by a multivariate Poisson regression model.

RESULTS

A total of 118 admissions (11%) had HH during their ICU stay. These patients had different baseline characteristics, longer median ICU stay (8 vs. 6 days, p < 0.001), and decreased ICU survival (43 vs. 83%, p < 0.001). The crude mortality rate ratio of admissions with HH was 4.62 (95% CI 3.63-5.86, p < 0.001). Regression analysis demonstrated strong mortality risk for admissions with HH requiring vasopressor therapy (adjusted rate ratio 4.91; 95% CI 2.51-9.60, p < 0.001), whereas HH was not significantly associated with mortality in admissions without vasopressor therapy (adjusted rate ratio 1.79, 95% CI 0.52-6.23, p = 0.359).

CONCLUSIONS

Hypoxic hepatitis (HH) occurs frequently in the medical ICU. The presence of HH is a strong risk factor for mortality in the ICU in patients requiring vasopressor therapy.

Clinical review: ketones and brain injury

Although much feared by clinicians, the ability to produce ketones has allowed humans to withstand prolonged periods of starvation. At such times, ketones can supply up to 50% of basal energy requirements. More interesting, however, is the fact that ketones can provide as much as 70% of the brain's energy needs, more efficiently than glucose. Studies suggest that during times of acute brain injury, cerebral uptake of ketones increases significantly. Researchers have thus attempted to attenuate the effects of cerebral injury by administering ketones exogenously. Hypertonic saline is commonly utilized for management of intracranial hypertension following cerebral injury. A solution containing both hypertonic saline and ketones may prove ideal for managing the dual problems of refractory intracranial hypertension and low cerebral energy levels. The purpose of the present review is to explore the physiology of ketone body utilization by the brain in health and in a variety of neurological conditions, and to discuss the potential for ketone supplementation as a therapeutic option in traumatic brain injury.

Lidocaïne test for easier and less time consuming assessment of liver function in several hepatic injury models

PURPOSE

In this study, we developed an ex vivo functional assay to assess liver metabolic capacity adapted from the lidocaïne test in rats.

METHODS

Animals used were subjected to different models of liver injury: hypothermic ischemia (H/I, n = 8), ischemia-reperfusion (I/R, n = 8) and CCl4 induced liver cirrhosis (n = 11), and compared with sham operated rats (n = 5). Livers were then extracted and a fragment of whole tissue was incubated with lidocaïne for 15, 30, 60, 120, 240, 360, and 720 min at which both lidocaïne and its major metabolite monoethylglycinexylidide (MEGX) were measured by high performance liquid chromatography (HPLC). A histological study and biochemical assays (transaminase levels) were also performed to further evaluate and confirm our data.

RESULTS

Pharmacokinetic profile of lidocaïne metabolism in sham-operated animals revealed that the maximum concentration of MEGX is achieved at 120 min. Both lidocaïne metabolism and MEGX formation levels were significantly altered in all three models of hepatic injury. The extent of hepatic damage was confirmed by increased levels of transaminase levels and alteration of hepatocyte's structure with areas of necrosis.

CONCLUSION

Our method provides reliable and reproducible results using only a small portion of liver which allows for a fast and easy assessment of liver metabolic capacity. Moreover, our method presents an alternative to the in vivo technique and seems more feasible in a clinical setting.