Multiple organ failure: is it disappearing?

Validation of postinjury multiple organ failure scores

Most multiple organ failure (MOF) scores were developed over a decade ago, but little has been done in terms of validation and to understand the differences between populations identified by each of them. Given the lack of a gold standard, validation must rely on association with objective adverse outcomes. Thus, we propose to (a) validate two widely accepted MOF scores (Denver and Marshall), examining their association with adverse outcomes in a postinjury population; and (b) compare risk factors, characteristics, and outcomes of patients identified by each score. The Denver MOF score grades (from 0-3) four organ dysfunctions (lung, kidney, liver, and heart) and defines MOF as a total score more than 3. The Marshall score grades, in addition, central nervous system and hematologic dysfunction (total of six organs on a 0- to 4-point scale). Using a prospectively collected data set, MOF was scored daily by both scores for 1,389 consecutive trauma patients with Injury Severity Score of more than 15 admitted from 1992 to 2004. Risk factors, clinical outcomes (death, ventilator-free days), and resource utilization outcomes (mechanical ventilation time, length of stay in the intensive care unit) were evaluated. Both scores were associated with areas under the receiver operating characteristic curves of 80 or greater (ideal value = 100), with values for the Denver score being slightly greater (albeit not significantly) regarding prediction of most outcomes. Values of sensitivity and specificity were more than 70% for death and ventilator-free days (with the Denver score showing a consistent trend toward greater specificity), but either sensitivity or specificity was less than 70% for mechanical ventilation time and length of stay in the intensive care unit, suggesting that these scores are appropriately biased toward clinical outcomes as opposed to resource utilization. Both scores performed well, with the Denver MOF score showing greater specificity, which, coupled with its simplicity, makes it an attractive tool for both the research and clinical environments. Basic concepts of each score can probably be combined to produce an improved MOF score.

Low incidence of multiple organ failure after major trauma

BACKGROUND

In major trauma patients, multiple organ failure (MOF) is considered a leading cause of death. Acute lung injury is deemed a "pacemaker" of MOF. The purpose of this study was to determine if incidence of organ failure and mortality in multiple trauma patients can be reduced by implementation of lung-protective strategies.

METHODS

All critically ill multiple trauma patients admitted to the ICU of a major trauma center in Berlin, Germany from January 1999 to December 2002 were analyzed retrospectively. Patients were ventilated pressure controlled with low tidal volumes and adequate PEEP.

RESULTS

n=287 patients were included. The most frequent injuries were traumatic brain injury (TBI-68%), chest trauma (68%), and lung contusions (55%). Injury severity score (ISS) was 32+/-19 (mean+/-standard deviation), polytraumaschluessel (PTS) 34+/-19, and APACHE II 14+/-7. During their ICU-stay 16 patients died, 9 (56%) from TBI. Single-organ-failure occurred in n=69 patients (24%, mortality 5%), two-organ-failure in n=22 (8%, mortality 14%), and MOF in n=9 (3%, mortality 13%); one patient died from MOF 14 days after trauma. The number of days on mechanical ventilation increased depending on the number of organs failed (R=0.618, p<0.001). Seven patients (2%) fulfilled ARDS criteria for longer than 24h despite optimized ventilatory settings, one died of irreversible shock. Patients with MOF had a significantly increased ICU-LOS (35+/-15 days) compared to patients without organ failure (11+/-11 days; p<0.001).

CONCLUSION

The low incidence of MOF in our series of trauma patients suggests that MOF may be prevented in some patients by implementation of lung-protective strategies. The improved outcome was associated with an increased ICU-LOS.

Leukocyte-endothelial interactions via ICAM-1 are detrimental in polymicrobial sepsis

Intercellular adhesion molecule 1 (ICAM-1) plays an important role in the transmigration of polymorphonuclear neutrophils (PMN) in sepsis. Moreover, the transmigration rate of leukocytes from the blood via endothelial adhesion molecules into tissues correlates with the severity of multi organ failure. We examined the effect of the deletion of the ICAM-1 gene in polymicrobial sepsis using a cecal ligation and puncture (CLP) sepsis model in mice. Twenty male ICAM-1 knockout (KO) mice and 20 wild-type (WT) male C57BL/6 mice were studied. CLP was performed. At several time points during a 96-hour postoperative observation period, we measured mortality, body weight, and temperature. The delayed type of hypersensitivity (DTH) reaction was determined by pinna swelling after sensitization with 50 microL of dinitrofluorobenzene (DNFB) 1%. Lymphocyte subpopulations (CD4, CD8, and CD56) and cytokines [tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and interleukin-10 (IL-10)] were measured using flow cytometry and ELISA testing, respectively. Also, a histologic examination of the liver and lung was performed. CLP-induced mortality was lower in the ICAM-1 group compared to normal mice (5% vs 45.0%). So were the ratios of lymphocyte subpopulations in the KO versus the WT group [CD4: 16.4 +/- 1.6% vs 25.7 +/- 4.7%; CD8: 18.3 +/- 1.4% vs 34.9 +/- 2.9%; natural killer (NK) cells: 5.6 +/- 0.3% vs 49.5 +/- 0.7%; P < 0.01]. And also the cytokine blood levels of the KO mice were significantly lower versus the WT mice (TNF-alpha: 67.2 +/- 42.2 vs 823.9 +/- 170.5 pg/mL; IL-1beta: 5.9 +/- 0.9 vs 296.2 +/- 66.2 pg/mL; IL-6: 223.1 +/- 48.8 vs 3062.5 +/- 1222.8 pg/mL; IL-10: 34.6 +/- 5.8 vs 1565.6 +/- 448.8 pg/mL; P < 0.01). With respect to the histology, significantly less leukocyte invasion and organ damage (eg, hydropic degeneration) were present in the ICAM-1-/- group compared to controls in liver and lung tissues. The DTH reaction was significantly decreased in ICAM-1-/- mice versus WT mice (0.34 vs 0.41 mm; P < 0.05). Our results demonstrate a significant reduction of mortality after septic challenge in ICAM-1-/- mice compared to normal mice. This is associated with a decrease in lymphocyte subpopulations, cytokine levels, and DTH type 4 reaction, possibly reflecting an overall attenuation of the immune system.

BLUNT CHEST TRAUMA INDUCES DELAYED SPLENIC IMMUNOSUPPRESSION

Severe blunt chest trauma is frequently associated with multiple organ failure and sepsis. Posttraumatic immunosuppression seems to play a major role in their development. However, the immunologic alterations following pulmonary contusion are insufficiently elucidated. Specifically, it remains unknown whether immunocompetent cells located distant from the site of the impact are affected. We therefore aimed to characterize the influence of pulmonary contusion on lymphocytes and splenic macrophages. Male C3H/HeN mice (n = 8-10/group) were anesthetized and subjected to trauma or sham procedure. Blunt chest trauma was induced by a blast wave focused on the thorax. Two or 24 h later, splenocytes and splenic macrophages were isolated and stimulated for 48 h. The cytokine release (IFN-gamma, IL-2, IL-3, IL-10, IL-12, IL-18) from splenocytes as well as from splenic macrophages (TNF-alpha, IL-10, IL-12, IL-18) and plasma levels of TNF-alpha and IL-6 were quantified by ELISA. The results indicate that at 2 h after blunt chest trauma, plasma TNF-alpha and IL-6 were markedly increased. At the same time, no differences in splenocyte cytokine production were detectable. However, at 24 h a significantly depressed cytokine release was observed in trauma animals. Furthermore, splenic macrophages showed a significantly decreased production of TNF-alpha, IL-10, and IL-12 at 24 h and markedly increased release of IL-18 at 2 h after trauma. These results indicate that blunt chest trauma causes severe immunodysfunction of lymphocytes and splenic macrophages. Thus, lung contusion as a localized type of trauma causes dysfunction of immunocompetent cell populations, which are located distant from the site of injury.

Multiple organ failure still a major cause of morbidity but not mortality in blunt multiple trauma

BACKGROUND

Multiple organ failure (OF/MOF) was found to be the major complication after blunt multiple trauma during the last 25 years and was correlated with a high mortality rate. Recently, several publications reported a decreased ARDS-related mortality, but there is little information about mortality rates from posttraumatic MOF. The purpose of this study was to describe the development of MOF-related death after blunt multiple trauma during the last 25 years.

METHODS

Blunt multiple trauma patients with an Injury Severity Score (ISS) > 15 points were included in this evaluation. According to the year of trauma, the population was divided into five groups: years 1975-1980 (n = 317), years 1981-1985 (n = 308), years 1986-1990 (n = 246), years 1991-1997 (n = 368), and years 1998-1999 (n = 122). Main outcome measurements were death, cause of death, and length of ICU stay. Patients dying within the first 24 hours after trauma were excluded. All data indicated in the Results section are presented as mean +/- SEM. Continuous variables were compared by ANOVA. Ordinal variables were analyzed by chi2 contingency table analysis and, if significant, subsequently by Fisher's exact test (two-tailed test, p < 0.05).

RESULTS

Mean ISS remained unchanged between 1975-1980 (ISS 29 +/- 1) and 1998-1999 (ISS 31 +/- 1) (p = 0.56). During the observation period, the mean age increased from 33 +/- 1 years (1975-1980) to 40 +/- 2 years (1998-1999) (p = 0.03). The overall incidence of OF/MOF slightly increased from 25.6% (1975-1980) to 33.6% (1998-1999) (p = 0.1). Length of ICU stay was not different between 1975-1980 (LOS: 14 +/- 1 d) and 1998-1999 (LOS: 19 +/- 2 d) (p = 1.0). The overall mortality decreased significantly, from 28.7% (1975-1980) to 13.9% (1998-1999) (p < 0.001). While the mortality due to severe head injuries remained unchanged (1975-1980, 8.2%; 1998-1999, 9.0%) (p = 0.85), mortality due to OF/MOF decreased significantly (p < 0.001), from 18.0% (1975-1980) to 4.1% (1998-1999). The age of patients dying from OF/MOF increased significantly (p = 0.04) during the observation period, from 44 +/- 3 years (1975-1980) to 63 +/- 6 years (1998-1999).

CONCLUSION

Although MOF incidence remains unchanged, there is a significant fall in MOF-related mortality in patients with severe trauma, and death from single organ failure is virtually absent. Severe brain injury is now the leading cause of death in patients with severe multiple injuries admitted to the ICU.