Incidence and outcome of early acute kidney injury in critically-ill trauma patients

Selection of appropriate reference creatinine estimate for acute kidney injury diagnosis in patients with severe trauma

BACKGROUND

In patients with severe trauma, the diagnosis of acute kidney injury (AKI) is important because it is a predictive factor for poor prognosis and can affect patient care. The diagnosis and staging of AKI are based on change in serum creatinine (SCr) levels from baseline. However, baseline creatinine levels in patients with traumatic injuries are often unknown, making the diagnosis of AKI in trauma patients difficult. This study aimed to enhance the accuracy of AKI diagnosis in trauma patients by presenting an appropriate reference creatinine estimate (RCE).

METHODS

We reviewed adult patients with severe trauma requiring intensive care unit admission between 2015 and 2019 (n=3,228) at a single regional trauma center in South Korea. AKI was diagnosed based on the current guideline published by the Kidney Disease: Improving Global Outcomes organization. AKI was determined using the following RCEs: estimated SCr75-modification of diet in renal disease (MDRD), trauma MDRD (TMDRD), admission creatinine level, and first-day creatinine nadir. We assessed inclusivity, prognostic ability, and incrementality using the different RCEs.

RESULTS

The incidence of AKI varied from 15% to 46% according to the RCE used. The receiver operating characteristic curve of TMDRD used to predict mortality and the need for renal replacement therapy (RRT) had the highest value and was statistically significant (0.797, P<0.001; 0.890, P=0.002, respectively). In addition, the use of TMDRD resulted in a mortality prognostic ability and the need for RRT was incremental with AKI stage.

CONCLUSIONS

In this study, TMDRD was feasible as a RCE, resulting in optimal post-traumatic AKI diagnosis and prognosis.

Risk Factors and Outcomes of Post-traumatic Acute Kidney Injury Requiring Renal Replacement Therapy: A Case-Control Study

Background

Acute kidney injury (AKI) following severe trauma is common. However, the requirement of renal replacement therapy (RRT) in these patients is rare and is associated with high morbidity and mortality. The primary objective of this study was to identify odds of risk factors, in particular, hypotension at presentation, for the requirement of RRT in patients with AKI following trauma.

Methods

We performed a case-control study involving patients who were admitted to the intensive care unit (ICU) at a level I trauma center for at least 24 hours. The primary outcome measure was a study of the odds of risk factors associated with the requirement of RRT in such patients. Univariate comparisons and multiple logistic regression analyses were done to identify other risk factors.

Results

The presence of crush injury, sepsis, and elevated serum creatinine (sCr) on arrival were identified to be independent risk factors for RRT requirement. Hypotension and exposure to radiocontrast or nephrotoxic antimicrobials were not found to be associated with the need for RRT. Acute kidney injury requiring RRT was associated with significantly increased ICU length of stay (15 days vs 5 days; p < 0.001) and higher mortality (83% vs 35%; p < 0.001).

Conclusion

The presence of crush injury, sepsis, and elevated sCr on presentation were identified to be independent risk factors while hypotension association was insignificant for AKI requiring RRT in our investigation.

How to cite this article

Soni KD, Singh A, Tyagi A, Singh Y, Aggarwal R, Trikha A. Risk Factors and Outcomes of Post-traumatic Acute Kidney Injury Requiring Renal Replacement Therapy: A Case-Control Study. Indian J Crit Care Med 2023;27(1):22-25.

Acute kidney injury development in polytrauma and the safety of early repeated contrast studies: A retrospective cohort study

BACKGROUND

The role of repeat intravenous contrast doses beyond initial contrast imaging in the development of acute kidney injury (AKI) for multiple injury patients admitted to the intensive care unit (ICU) is not fully understood. We hypothesized that additional contrast doses are potentially modifiable risk factors for worse outcomes.

METHODS

An 8-year retrospective study of our institutional prospective postinjury multiple organ failure database was performed. Adult ICU admissions that survived >72 hours with Injury Severity Score (ISS) of >15 were included. Patients were grouped based on number of repeat contrast studies received after initial imaging. Initial vital signs, resuscitation data, and laboratory parameters were collected. Primary outcome was AKI (Kidney Disease: Improving Global Outcomes criteria), and secondary outcomes included contrast-induced acute kidney injury (CI-AKI; >25% or >44 μmol/L increase in creatinine within 72 hours of contrast administration), multiple organ failure, length of stay, and mortality.

RESULTS

Six-hundred sixty-three multiple injury patients (age, 45.3 years [SD, 9.1 years]; males, 75%; ISS, 25 (interquartile range, 20-34); mortality, 5.4%) met the inclusion criteria. The incidence of AKI was 13.4%, and CI-AKI was 14.5%. Multivariate analysis revealed that receiving additional contrast doses within the first 72 hours was not associated with AKI (odds ratio, 1.33; confidence interval, 0.80-2.21; p = 0.273). Risk factors for AKI included higher ISS ( p < 0.0007), older age ( p = 0.0109), higher heart rate ( p = 0.0327), lower systolic blood pressure ( p = 0.0007), and deranged baseline blood results including base deficit ( p = 0.0042), creatinine ( p < 0.0001), lactate ( p < 0.0001), and hemoglobin ( p = 0.0085). Acute kidney injury was associated with worse outcomes (ICU length of stay: 8 vs. 3 days, p < 0.0001; mortality: 16% vs. 3.8%, p < 0.0001; MOF: 42% vs. 6.6%, p < 0.0001).

CONCLUSION

There is a limited role of repeat contrast administration in AKI development in ICU-admitted multiple injury patients. The clinical significance of CI-AKI is likely overestimated, and it should not compromise essential secondary imaging from the ICU. Further prospective studies are needed to verify our results.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

The Clinical Impact of Platelets on Post-Injury Serum Creatinine Concentration in Multiple Trauma Patients: A Retrospective Cohort Study

Background and objective: Platelets contribute to the immunological response after multiple trauma. To determine the clinical impact, this study analyzes the association between platelets and creatinine concentration as an indicator of kidney function in polytraumatized patients. Methods: We investigated all patients presenting an Injury Severity Score (ISS) ≥16 for a 2-year period at our trauma center. Platelet counts and creatinine concentrations were analyzed, and correlation analysis was performed within 10 days after multiple trauma. Results: 83 patients with a median ISS of 22 were included. Platelet count was decreased on day 3 (p ≤ 0.001) and increased on day 10 (p ≤ 0.001). Platelet count was elevated on day 10 in younger patients and diminished in severely injured patients (ISS ≥35) on day 1 (p = 0.012) and day 3 (p = 0.011). Creatinine concentration was decreased on day 1 (p = 0.003) and day 10 (p ≤ 0.001) in female patients. Age (p = 0.01), male sex (p = 0.004), and injury severity (p = 0.014) were identified as factors for increased creatinine concentration on day 1, whereas platelets (p = 0.046) were associated with decreased creatinine concentrations on day 5 after multiple trauma. Conclusions: Kinetics of platelet count and creatinine concentration are influenced by age, gender, and trauma severity. There was no clear correlation between platelet counts and creatinine concentration. However, platelets seem to have a modulating effect on creatinine concentrations in the vulnerable phase after trauma.

R, Rehman EU. Etiology, Clinical Profile, and Short-Term Outcome of Children With Acute Kidney Injury

Background: Acute kidney injury (AKI) is a common clinical syndrome in hospitalized children and it imposes heavy burden of mortality and morbidity. In resource-constraint settings, management of AKI is very challenging and associated with adverse outcomes. The aim of this study was to determine the clinico-etiological profile and outcome of AKI.

Methodology: This prospective observational study was done at the department of pediatric nephrology and pediatric intensive care unit, National Institute of Child Health, Karachi, Pakistan from December 2020 to May 2021. A total of 130 children aged 1 month to 15 years, diagnosed with AKI irrespective of the underlying cause were included. Detailed medical information of each child including medical history, examination, and baseline investigations were obtained. Clinical and etiological profile of patients was noted. The patients were followed up to three months and the outcome was noted.

Results: In a total of 130 children, 82 (63.1%) were male. The mean age was 5.5±4.4 years (ranging between 1 month and 15 years). There were 117 (90.0%) children who were referred from other centers for either dialysis or surgical treatment. Prerenal cause of AKI was found in 66 (50.8%) children, followed by renal 53 (40.8%) and postrenal in 11 (8.5%) cases. Fever and shortness of breath were the most common clinical presenting symptoms in 102 (78.5%) and 100 (76%) cases, respectively. There were 45 (34.6%) cases who were managed conservatively, 80 (61.5%) needed dialysis, while three children were managed with plasmapheresis and two required surgical intervention in the emergency department. At three-month follow-up period, 64 (49.2%) children recovered (including nine with partial recovery), 46 (36.1%) expired, 9 (6.9%) developed end-stage renal disease, while 11 (8.5%) had chronic kidney disease.

Conclusion: Sepsis, nephrotoxic drugs, and acute glomerulonephritis were the major causes of AKI at our center. Mortality was high among children presenting with AKI. A relatively high proportion of children with younger age, septic AKI, and presentation in critical condition could be the reasons for this high mortality.

Overview of Renal Replacement Therapy Use in a General Intensive Care Unit

OBJECTIVES

Population-based studies regarding renal replacement therapy (RRT) used in critical care populations are useful to understand the trend and impact of medical care interventions. We describe the use of RRT and associated outcomes (mortality and length of intensive care stay) in a level 1 hospital.

DESIGN

A retrospective descriptive observational study.

PATIENTS

Critically ill patients admitted to the ICU from 1 January to 31 December 2018.

INTERVENTIONS

Age, gender, ward of admission, primary organ dysfunction at admission, length of hospital stay (LOS), mechanical ventilation, APACHE, SOFA and ISS scores, the use of vasopressors, transfusion, RRT and the number of RRT sessions were extracted.

RESULTS

1703 critically ill patients were divided into two groups: the RRT-group (238 patients) and the non-RRT group (1465 patients). The mean age was 63.58 ± 17.52 (SD) in the final ICU studied patients (64.72 ± 16.64 SD in the RRT-group), 60.5% being male. Patients admitted from general surgery ward needing RRT were 41.4%. The specific scores, the use of vasopressors, transfusions and mortality were higher in the RRT-group. The ICU LOS was superior in the RRT-group, regardless of the primary organ dysfunction.

CONCLUSIONS

RRT was practiced in 13.9% of patients (especially after age of 61), with mortality being the outcome for 66.8% of the RRT-group patients. All analyzed data were higher in the RRT group, especially for multiple trauma and surgical patients, or patients presenting cardiac or renal dysfunctions at admission. We found significant increased ISS scores in the RRT-group, a significant association between the need of vasopressors or transfusion requirement and RRT use, and an association in the number of RRT sessions and LOS (p < 0.001).

Risk factors for end-stage renal disease in patients with trauma and stage 3 acute kidney injury

Research on long-term renal outcomes in patients with acute kidney injury (AKI) and trauma, especially those with traumatic brain injury (TBI), has been limited.In this study, we enrolled patients with stage 3 AKI as per the Kidney Disease Improving Global Outcomes guidelines, who initiated renal replacement therapy (RRT). These patients were divided into 2 groups depending on the presence of TBI. Comparing the baseline characteristics and management strategies of each group, we analyzed whether TBI affects the progression of kidney disease.Between January 1, 2014 and June 30, 2020, 51 patients who initiated RRT due to AKI after trauma were enrolled in this study. TBI was identified in 20 patients, and the clinical conditions were not related to TBI in the remaining 31. The study endpoint was set to determine whether the patients of each group needed RRT persistently at discharge and at the time of recent outpatient clinic. Six (30.0%) out of 20 patients with TBI and 2 (6.5%) out of 31 patients without TBI required conventional hemodialysis, as per the most recent data. No significant within-group differences were found in terms of the baseline characteristics and management strategies. In the logistic regression analysis, TBI was independently associated with disease progression to end-stage renal disease.TBI is a risk factor for end-stage renal disease in patients with trauma and stage 3 AKI who initiate RRT.

Prediction of early acute kidney injury after trauma using prehospital systolic blood pressure and lactate levels: A prospective validation study

BACKGROUND

Acute kidney injury (AKI) after trauma is a major complication independently associated with a prolonged hospital stay and increased mortality. We previously reported that the prehospital systolic blood pressure (SBP) and early hospital arterial lactate level, along with specific cut-off values, show good performance in the early prediction of AKI using AUC-ROC [1]. The purpose of this study was to prospectively validate whether or not these parameters are predictive of newly occurring AKI after trauma.

METHODS

This was a prospective review of trauma patients who were admitted to a single trauma center from January to December 2019. Patients who were <16 years old, who had burns, and who had chronic kidney disease were excluded. AKI was defined according to the Risk, Injury, Failure, Loss of the kidney function, and End-stage kidney disease (RIFLE) classification based on serum creatinine alone. Patients with a low prehospital SBP (≤126 mmHg) and high lactate levels (≥2.5 mmol/L) were defined as the high-risk group, and other patients were defined as the low-risk group.

RESULTS

A total of 489 trauma patients were admitted to our center, of whom 403 were eligible for the study. The high-risk group consisted of 38 patients, and the low-risk group consisted of 365 patients. The incidence of severe AKI in Stage Injury and Failure was significantly higher in the high-risk group (5 patients, 13.2%) than in the low-risk group (7 patients, 1.9%), with an odds ratio of 7.75 and 95% confidence interval of 2.33-25.77.

CONCLUSIONS

These predictors showed good performance in the early prediction of severe AKI after trauma. Early prediction of the high-risk groups for severe AKI after trauma prompting early treatment may help improve the prognosis of trauma patients.

Neutrophil Gelatinase-associated Lipocalin Predicts Post-traumatic Acute Kidney Injury in Severely Injured Patients

BACKGROUND

Early detection of acute kidney injury (AKI) is crucial in the management of multiple-organ dysfunction syndrome in severely injured patients. Standard laboratory parameters usually increase with temporal delay. Therefore, we evaluated neutrophil gelatinase-associated lipocalin (NGAL) as an early marker for acute kidney injury.

PATIENTS AND METHODS

We retrospectively evaluated patients admitted to a level 1 trauma center. We collected clinicodemographic data and measured kidney-related factors and plasma cytokines.

RESULTS

A total of 39 patients were included. Patients with AKI had significantly higher levels not only of serum creatinine and urea, but also of NGAL (all p<0.001) than patients without AKI. The optimal NGAL cut-off value was determined to be 177 ng/ml, showing significant correlation with imminent or manifest AKI (p<0.001). Other independent markers correlated with AKI included pre-existing chronic kidney disease, use of catecholamines, and severe injury (p<0.001).

CONCLUSION

The serum level of NGAL is feasible early predictor of AKI.

Importance of duration of acute kidney injury after severe trauma: a cohort study

Background

Acute kidney injury (AKI) is common after severe trauma. AKI incidence and AKI stage have previously been shown to be associated with poor outcomes after trauma. However, AKI duration may also be important for outcomes after trauma, given that it is associated with long-term morbidity and mortality in general intensive care unit (ICU) and hospitalized patients. We hypothesized that duration of AKI is independently associated with poor outcomes after trauma.

Methods

A cohort study was conducted at a single, level 1 trauma center. Patients admitted to the ICU between 2009 and 2018 were included. Data were extracted from the trauma registry and electronic medical records. AKI within 7 days from presentation was defined according to the Kidney Disease Improving Global Outcomes guidelines. Multivariable analyses were performed to assess the association between AKI incidence, AKI stage, and AKI duration with outcomes including prolonged ICU and hospital length of stay, discharge to home, and mortality.

Results

Of 7049 patients included, 72% were male, the median age was 41 years (IQR 27–58), and 10% died. The AKI incidence was 45%, with 69% of these patients presenting with AKI on arrival. The majority (73%) of patients who suffered AKI recovered within 2 days. After adjustment in separate models, AKI incidence, AKI stage and AKI duration were each associated with prolonged hospitalization, an unfavorable discharge disposition, and mortality. AKI stage and duration were not used in the same model due to collinearity.

Conclusions

Post-traumatic AKI was common on arrival and frequently short lasting. Duration correlated with highest AKI stage, and both were separately associated with prolonged hospitalization, discharge destination other than home, and mortality on adjusted analyses. Given the high incidence of AKI on arrival, stage or duration may be better targets for future interventions and quality improvement initiatives to improve outcomes after post-traumatic AKI.

Level of evidence

III. Prognostic.

Valproic Acid Protects Against Acute Kidney Injury in Hemorrhage and Trauma

INTRODUCTION

Trauma is the leading cause of death among young people. These patients have a high incidence of kidney injury, which independently increases the risk of mortality. As valproic acid (VPA) treatment has been shown to improve survival in animal models of lethal trauma, we hypothesized that it would also attenuate the degree of acute kidney injury.

METHODS

We analyzed data from two separate experiments where swine were subjected to lethal insults.  Model 1: hemorrhage (50% blood volume hemorrhage followed by 72-h damage control resuscitation). Model 2: polytrauma (traumatic brain injury, 40% blood volume hemorrhage, femur fracture, rectus crush and grade V liver laceration). Animals were resuscitated with normal saline (NS) +/- VPA 150 mg/kg after a 1-h shock phase in both models (n = 5-6/group). Serum samples were analyzed for creatinine (Cr) using colorimetry on a Liasys 330 chemistry analyzer. Proteomic analysis was performed on kidney tissue sampled at the time of necropsy.

RESULTS

VPA treatment significantly (P < 0.05) improved survival in both models. (Model 1: 80% vs 20%; Model 2: 83% vs. 17%). Model 1 (Hemorrhage alone): Cr increased from a baseline of 1.2 to 3.0 in NS control animals (P < 0.0001) 8 h after hemorrhage, whereas it rose only to 2.1 in VPA treated animals (P = 0.004). Model 2 (Polytrauma): Cr levels increased from baseline of 1.3 to 2.5 mg/dL (P = 0.01) in NS control animals 4 h after injury but rose to only 1.8 in VPA treated animals (P = 0.02). Proteomic analysis of kidney tissue identified metabolic pathways were most affected by VPA treatment.

CONCLUSIONS

A single dose of VPA (150 mg/kg) offers significant protection against acute kidney injury in swine models of polytrauma and hemorrhagic shock.

Characteristics and Outcomes of Critically Ill Trauma Patients in Australia and New Zealand (2005-2017)

OBJECTIVES

To compare the characteristics of adults admitted to the ICU in Australia and New Zealand after trauma with nonelective, nontrauma admissions. To describe trends in hospital mortality and rates of discharge home among these two groups.

DESIGN

Retrospective review (2005-2017) of the Australia and New Zealand Intensive Care Society's Center for Outcome and Resource Evaluation Adult Patient Database.

SETTING

Adult ICUs in Australia and New Zealand.

PATIENTS

Adult (≥17 yr), nonelective, ICU admissions.

INTERVENTION

Observational study.

MEASUREMENTS AND MAIN RESULTS

We compared 77,002 trauma with 741,829 nonelective, nontrauma patients. Trauma patients were younger (49.0 ± 21.6 vs 60.6 ± 18.7 yr; p < 0.0001), predominantly male (73.1% vs 53.9%; p < 0.0001), and more frequently treated in tertiary hospitals (74.7% vs 45.8%; p < 0.0001). The mean age of trauma patients increased over time but was virtually static for nonelective, nontrauma patients (0.72 ± 0.02 yr/yr vs 0.03 ± 0.01 yr/yr; p < 0.0001). Illness severity increased for trauma but fell for nonelective, nontrauma patients (mean Australia and New Zealand risk of death: 0.10% ± 0.02%/yr vs -0.21% ± 0.01%/yr; p < 0.0001). Trauma patients had a lower hospital mortality than nonelective, nontrauma patients (10.0% vs 15.8%; p < 0.0001). Both groups showed an annual decline in the illness severity adjusted odds ratio (odds ratio) of hospital mortality, but this was slower among trauma patients (trauma: odds ratio 0.976/yr [0.968-0.984/yr; p < 0.0001]; nonelective, nontrauma: odds ratio 0.957/yr [0.955-0.959/yr; p < 0.0001]; interaction p < 0.0001). Trauma patients had lower rates of discharge home than nonelective, nontrauma patients (56.7% vs 64.6%; p < 0.0001). There was an annual decline in illness severity adjusted odds ratio of discharge home among trauma patients, whereas nonelective, nontrauma patients displayed an annual increase (trauma: odds ratio 0.986/yr [0.981-0.990/yr; p < 0.0001]; nonelective, nontrauma: odds ratio 1.014/yr [1.012-1.016/yr; p < 0.0001]; interaction: p < 0.0001).

CONCLUSIONS

The age and illness severity of adult ICU trauma patients in Australia and New Zealand has increased over time. Hospital mortality is lower for trauma than other nonelective ICU patients but has fallen more slowly. Trauma patients have become less likely to be discharged home than other nonelective ICU patients.

Prehospital Blood Pressure and Lactate are Early Predictors of Acute Kidney Injury After Trauma

BACKGROUND

The purpose of this study is to report the prevalence of acute kidney injury (AKI) after trauma in our center, describe the risk factors associated with AKI, and determine whether these risk factors help avoid AKI.

MATERIALS AND METHODS

We retrospectively analyzed the data which were prospectively collected from a single center trauma registry from January 2017 to December 2018. Patients who were <16 years of age, patients with burns, and patients with chronic kidney disease were excluded from the present study. AKI was defined according to the risk, injury, failure, loss of the kidney function, and end-stage kidney disease (RIFLE) classification from serum creatinine alone. A logistic regression analysis was performed to identify prehospital and early hospital risk factors for AKI.

RESULTS

There were 806 trauma patients recorded in the database. One hundred thirty cases were excluded based on the abovementioned exclusion criteria. Six hundred seventy-six patients were included in the analysis. The prevalence of AKI in the overall population was 14.5% including 10.5% of patients with stage R, 3.0% of patients with stage I and 1.0% with stage F. The incidence of AKI increased to 36.3%, 12.1% and 3.3% in the subgroup of patients with hemorrhagic shock. The multivariate analysis revealed that the minimum prehospital systolic blood pressure and arterial lactate level were independent predictors of AKI. The model showed good discrimination with an area under the receiver operating characteristic curve (AUC-ROC) of 0.867 and 0.852 in the prediction of AKI stage I or F. The cutoff values were ≤126 mmHg and ≥2.5 mmol/L, respectively.

CONCLUSION

These parameters showed good performance in the early prediction of AKI after trauma. They are associated with the early onset of AKI after trauma and may be an early predictor of the effects of treatment to prevent AKI.

Long-term outcomes following vehicle trauma related acute kidney injury requiring renal replacement therapy: a nationwide population study

Acute kidney injury (AKI) is a frequent complication of traumatic injury; however, long-term outcomes such as mortality and end-stage kidney disease (ESKD) have been rarely reported in this important patient population. We compared the long-term outcome of vehicle-traumatic and non-traumatic AKI requiring renal replacement therapy (AKI-RRT). This nationwide cohort study used data from the Taiwan National Health Insurance Research Database. Vehicle-trauma patients who were suffered from vehicle accidents developing AKI-RRT during hospitalization were identified, and matching non-traumatic AKI-RRT patients were identified between 2000 and 2010. The incidences of ESKD, 30-day, and long-term mortality were evaluated, and clinical and demographic associations with these outcomes were identified using Cox proportional hazards regression models. 546 vehicle-traumatic AKI-RRT patients, median age 47.6 years (interquartile range: 29.0–64.3) and 76.4% male, were identified. Compared to non-traumatic AKI-RRT, vehicle-traumatic AKI-RRT patients had longer length of stay in hospital [median (IQR):15 (5–34) days vs. 6 (3–11) days; p < 0.001). After propensity matching with non-traumatic AKI-RRT cases with similar demographic and clinical characteristics. Vehicle-traumatic AKI-RRT patients had lower rates of long-term mortality (adjusted hazard ratio (HR), 0.473; 95% CI, 0.392–0.571; p < 0.001), but similar rates of ESKD (HR, 1.166; 95% CI, 0.829–1.638; p = 0.377) and short-term risk of death (HR, 1.134; 95% CI, 0.894–1.438; p = 0.301) as non-traumatic AKI-RRT patients. In competing risk models that focused on ESKD, vehicle-traumatic AKI-RRT patients were associated with lower ESKD rates (HR, 0.552; 95% CI, 0.325–0.937; p = 0.028) than non-traumatic AKI-RRT patients. Despite severe injuries, vehicle-traumatic AKI-RRT patients had better long-term survival than non-traumatic AKI-RRT patients, but a similar risk of ESKD. Our results provide a better understanding of long-term outcomes after vehicle-traumatic AKI-RRT.

Influence of patients’ clinical features at intensive care unit admission on performance of cell cycle arrest biomarkers in predicting acute kidney injury

Objectives

Identification of acute kidney injury (AKI) can be challenging in patients with a variety of clinical features at intensive care unit (ICU) admission, and the capacity of biomarkers in this subpopulation has been poorly studied. In our study we examined the influence that patients’ clinical features at ICU admission have over the predicting ability of the combination of urinary tissue inhibitor of metalloproteinase-2 (TIMP2) and insulin-like growth factor binding protein 7 (IGFBP7).

Methods

Urinary [TIMP2]•[IGFBP7] were measured for all patients upon admission to ICU. We calculated the receiver operating characteristics (ROC) curves for AKI prediction in the overall cohort and for subgroups of patients according to etiology of ICU admission, which included: sepsis, trauma, neurological conditions, cardiovascular diseases, respiratory diseases, and non-classifiable causes.

Results

In the overall cohort of 719 patients, 239 (33.2%) developed AKI in the first seven days. [TIMP2]•[IGFBP7] at ICU admission were significantly higher in AKI patients than in non-AKI patients. This is true not only for the overall cohort but also in the other subgroups. The area under the ROC curve (AUC) for [TIMP2]•[IGFBP7] in predicting AKI in the first seven days was 0.633 (95% CI 0.588–0.678), for the overall cohort, with sensitivity and specificity of 66.1 and 51.9% respectively. When we considered patients with combined sepsis, trauma, and respiratory disease we found a higher AUC than patients without these conditions (0.711 vs. 0.575; p=0.002).

Conclusions

The accuracy of [TIMP2]•[IGFBP7] in predicting the risk of AKI in the first seven days after ICU admission has significant variability when the reason for ICU admission is considered.

Incidence and Risk Factors for Acute Kidney Injury in Severely Injured Patients Using Current Kidney Disease: Improving Global Outcomes Definitions

BACKGROUND

Acute kidney injury (AKI) is a significant cause of morbidity and mortality for critically injured trauma patients. The Kidney Disease: Improving Global Outcomes (KDIGO) practice guideline is the most up-to-date classification for AKI. The aims of this study were to determine the incidence and risk factors for AKI in critically injured trauma patients using the current KDIGO definitions.

STUDY DESIGN

A prospective cohort study was performed at our academic, level 1 trauma center, from September 2017 to August 2018. All adult trauma patients admitted to the surgical ICU were included. The primary outcome was the development of AKI, as defined by KDIGO. Secondary outcomes included hospital and ICU length of stay, ventilator days, and mortality.

RESULTS

There were 466 patients included and 314 (67%) developed AKI. Those who developed AKI were more often hypotensive on admission (7% vs 2%), had higher Injury Severity Scores (ISS) (19 vs 13), were more likely to have severe injuries to the chest (40% vs 24%) and extremities (20% vs 6%), received transfusion (41% vs 21%), sustained crush injuries (8% vs 1%), received radiocontrast (75% vs 47%), nephrotoxic medication (74% vs 60%), or vasopressors (15% vs 3%). After multivariate analysis, risk factors independently associated with AKI include age, Injury Severity Score (ISS), severe extremity injuries, radiocontrast, and vasopressors. Those who developed AKI had higher mortality (9% vs 2%).

CONCLUSIONS

Using current KDIGO criteria, the incidence of AKI in critically injured trauma patients was higher than previously reported. Older patients, with more severe injuries to their extremities and chest and who have suffered crush injuries, appear to be the most a risk. AKI in the critically injured patient results in an almost 5-fold increase in mortality.

The incidence and associations of acute kidney injury in trauma patients admitted to critical care: A systematic review and meta-analysis

BACKGROUND

As more patients are surviving the initial effects of traumatic injury clinicians are faced with managing the systemic complications of severe tissue injury. Of these, acute kidney injury (AKI) may be a sentinel complication contributing to adverse outcomes.

OBJECTIVE

To establish the incidence of AKI in patients admitted to critical care after major trauma, to explore any risk factors and to evaluate the association of AKI with outcomes.

DATA SOURCES

Systematic search of MEDLINE, Excerpta Medica database and Cochrane library from January 2004 to April 2018.

STUDY SELECTION

Studies of adult major trauma patients admitted to critical care that applied consensus AKI criteria (risk injury failure loss end stage [RIFLE], AKI network, or kidney disease improving global outcomes) and reported clinical outcomes were assessed (PROSPERO Registration: CRD42017056781). Of the 35 full-text articles selected from the screening, 17 (48.6%) studies were included.

DATA EXTRACTION AND SYNTHESIS

We followed the PRISMA guidelines and study quality was assessed using the Newcastle-Ottawa score. The pooled incidence of AKI and relative risk of death were estimated using random-effects models.

MAIN OUTCOMES AND MEASURES

Incidence of AKI was the primary outcome. The secondary outcome was study-defined mortality.

RESULTS

We included 17 articles describing AKI outcomes in 24,267 trauma patients. The pooled incidence of AKI was 20.4% (95% confidence interval [CI], 16.5-24.9). Twelve studies reported the breakdown of stages of AKI with 55.7% of patients classified as RIFLE-R or stage 1, 30.3% as RIFLE-I or stage 2, and 14.0% as RIFLE-F or stage 3. The pooled relative risk of death with AKI compared was 3.6 (95% CI, 2.4-5.3). In addition, there was a concordant increase in odds of death among six studies that adjusted for multiple variables (adjusted odds ratio, 2.7; 95% CI, 1.9-3.8; p = <0.01).

CONCLUSION

Acute kidney injury is common after major trauma and associated with increased mortality. Future research is warranted to reduce the potential for harm associated with this subtype of AKI.

LEVEL OF EVIDENCE

Systematic review and meta-analysis, level III.

Positive Fluid Balance and Association with Post-Traumatic Acute Kidney Injury

BACKGROUND

Acute kidney injury (AKI) is common in severely injured trauma patients and is associated with poor outcomes. A positive fluid balance is associated with AKI and poor long-term renal outcomes among general ICU and cardiac surgery patients. Currently, the optimal endpoint of resuscitation of severely injured trauma patients is unknown, which may result in excess fluid administration. We hypothesized that positive fluid balance is common after severe trauma and is associated with increased AKI development.

STUDY DESIGN

A cohort study of adult (≥16 years old) trauma patients requiring ICU admission from January 2017 to June of 2017 was conducted. Patients were excluded for early death, rhabdomyolysis, or previous history of end-stage renal disease or congestive heart failure. Acute kidney injury within 7 days of admission was defined according to Kidney Disease Improving Global Outcomes creatinine-based criteria. Univariate and multivariable analyses were performed.

RESULTS

Of 364 patients, 74% were male. The median age was 41 years (interquartile range [IQR] 27 to 59 years), and the median Injury Severity Score (ISS) was 18 (IQR 10 to 29). Positive fluid balance (>2 L) was observed in 49% of patients. Acute kidney injury was diagnosed in 105 (29%) patients. After adjustment, there was an increased risk of AKI with a positive fluid balance >2 L (relative risk [RR] 1.98 [95% CI 1.24 to 3.17]). Additionally, the risk of AKI incrementally increased by 1.22 with each liter fluid positive above a zero balance (95% CI 1.11 to 1.34).

CONCLUSIONS

Positive fluid balance in excess of 2 L at 48 hours occurs in half of severely injured trauma patients, and fluid positivity is independently and incrementally associated with AKI development. Fluid responsiveness should be investigated as an end point of post-traumatic resuscitation to prevent unnecessary fluid administration and subsequent AKI.

Choice of Reference Creatinine for Post-Traumatic Acute Kidney Injury Diagnosis

BACKGROUND

Acute kidney injury (AKI) after trauma is associated with poor outcomes. According to current guidelines, a diagnosis of AKI should be made based on an increase in serum creatinine from a reference value. However, a true reference is often unknown in patients presenting with traumatic injury. The aim of this study was to determine the optimal reference creatinine estimate for post-traumatic AKI diagnosis and staging. The optimal reference estimate was defined by a high incidence, strong prognostic ability, and incrementality at each stage.

STUDY DESIGN

This was a cohort study of adult trauma patients (older than 16 years) requiring ICU admission between 2009 and 2018 (n = 8,026) at a single Level I trauma center. AKI was determined using the following 4 reference creatinine estimates: Modified Diet of Renal Diseases (MDRD), Trauma MDRD, admission creatinine, and the first-day creatinine nadir. Inclusivity was assessed by incidence of AKI diagnosed with different reference creatinine estimates; prognostic ability was assessed by multivariable modified Poisson regression; and incrementality was assessed by correlation of mortality risk by AKI stage.

RESULTS

There was a wide range of AKI incidence, from 21% when using admission creatinine to 76% using the Trauma MDRD. The MDRD reference creatinine estimate resulted in an AKI incidence of 41% and a diagnosis that was both prognostic of mortality and incremental with each AKI stage. All other reference estimates resulted in AKI diagnoses that were either not prognostic or not incremental.

CONCLUSIONS

Reference creatinine estimate determines the clinical importance of AKI diagnoses. In this study, the MDRD reference resulted in optimal AKI diagnoses.

An epidemiologic overview of acute kidney injury in intensive care units

SUMMARY INTRODUCTION Acute kidney injury (AKI) is a frequent event among critically ill patients hospitalized in intensive care units (ICU) and represents a global public health problem, being imperative an interdisciplinary approach. OBJECTIV To investigate, through literature review, the AKI epidemiology in ICUs. METHODS: Online research in Medline, Scientific Electronic Library Online, and Latin American and Caribbean Literature in Health Sciences databases, with analysis of the most relevant 47 studies published between 2010 and 2017. RESULTS Data of the 67,033 patients from more than 300 ICUs from different regions of the world were analyzed. The overall incidence of AKI ranged from 2.5% to 92.2%, and the mortality from 5% to 80%. The length of ICU stay ranged from five to twenty-one days, and the need for renal replacement therapy from 0.8% to 59.2%. AKI patients had substantially higher mortality rates and longer hospital stays than patients without AKI. CONCLUSION AKI incidence presented high variability among the studies. One of the reasons for that were the different criteria used to define the cases. Availability of local resources, renal replacement therapy needs, serum creatinine at ICU admission, volume overload, and sepsis, among others, influence mortality rates in AKI patients.

Obese trauma patients have increased need for dialysis

PURPOSE

Obesity is a risk factor for the development of acute kidney injury but its effect on the need for dialysis in trauma has not been elucidated. Additionally, the contribution that obesity has towards risk of mortality in trauma is unclear. We hypothesized that patients with a higher body mass index (BMI) will have a higher risk for need of dialysis and mortality after trauma.

METHODS

This is a retrospective analysis using the National Trauma Data Bank. All patients ≥ 8 years old were grouped based on BMI: normal (18.5-24.99 kg/m²), obese (30-34.99 kg/m²), severely obese (35-39.99 kg/m²) and morbidly obese (≥ 40 kg/m²). The primary outcome was hemodialysis initiation. The secondary outcome was mortality during the index hospitalization.

RESULTS

From 988,988 trauma patients, 571,507 (57.8%) had a normal BMI, 233,340 (23.6%) were obese, 94,708 (9.6%) were severely obese, and 89,433 (9.0%) were morbidly obese. The overall rate of hemodialysis was 0.3%. After adjusting for covariates, we found that obese (OR 1.36, CI 1.22-1.52, p < 0.001), severely obese (OR 1.89, CI 1.66-2.15, p < 0.001) and morbidly obese (OR 2.04, CI 1.82-2.29, p < 0.001) patients had a stepwise increased need for hemodialysis after trauma. Obese patients had decreased (OR 0.92, CI 0.88-0.95, p < 0.001), severely obese had similar (OR 1.02, CI 0.97-1.08, p = 0.50) and morbidly obese patients had increased (OR 1.06, CI 1.01-1.12, p = 0.011) risk of mortality after trauma.

CONCLUSIONS

Obesity was associated with an increased risk for dialysis after trauma. Mortality risk was reduced in obese, similar in severely obese, and increased in morbidly obese trauma patients suggesting an inflection threshold BMI for risk of mortality in trauma.

Endovascular variable aortic control (EVAC) versus resuscitative endovascular balloon occlusion of the aorta (REBOA) in a swine model of hemorrhage and ischemia reperfusion injury

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is effective at limiting hemorrhage from noncompressible sources and restoring but causes progressive distal ischemia, supraphysiologic pressures, and increased cardiac afterload. Endovascular variable aortic control (EVAC) addresses these limitations, while still controlling hemorrhage. Previous work demonstrated improved outcomes following a 90-minute intervention period in an uncontrolled hemorrhage model. The present study compares automated EVAC to REBOA over an occlusion period reflective of contemporary REBOA usage.

METHODS

Following instrumentation, 12 Yorkshire-cross swine underwent controlled 25% hemorrhage, a 45-minute intervention period of EVAC or REBOA, and subsequent resuscitation with whole blood and critical care for the remainder of a 6-hour experiment. Hemodynamics were acquired continuously, and laboratory parameters were assessed at routine intervals. Tissue was collected for histopathologic analysis.

RESULTS

No differences were seen in baseline parameters. During intervention, EVAC resulted in more physiologic proximal pressure augmentation compared with REBOA (101 vs. 129 mm Hg; 95% confidence interval [CI], 105-151 mm Hg; p = 0.04). During critical care, EVAC animals required less than half the amount of crystalloid (3,450 mL; 95% CI, 1,215-5,684 mL] vs. 7,400 mL [95% CI, 6,148-8,642 mL]; p < 0.01) and vasopressors (21.5 ng/kg [95% CI, 7.5-35.5 ng/kg] vs. 50.5 ng/kg [95% CI, 40.5-60.5 ng/kg]; p = 0.05) when compared with REBOA animals. Endovascular variable aortic control resulted in lower peak and final lactate levels. Endovascular variable aortic control animals had less aortic hyperemia from reperfusion with aortic flow rates closer to baseline (36 mL/kg per minute [95% CI, 30-44 mL/kg per minute] vs. 51 mL/kg per minute [95% CI, 41-61 mL/kg per minute]; p = 0.01).

CONCLUSIONS

For short durations of therapy, EVAC produces superior hemodynamics and less ischemic insult than REBOA in this porcine-controlled hemorrhage model, with improved outcomes during critical care. This study suggests EVAC is a viable strategy for in-hospital management of patients with hemorrhagic shock from noncompressible sources. Survival studies are needed to determine if these early differences persist over time.

Risk factors and outcome of acute kidney injury in elderly trauma patients

BACKGROUND

Acute Kidney Injury (AKI) is associated with significant morbidity. The risk factors for AKI in elderly trauma patients have not been defined.

METHODS

Injured patients 75 years old or older from 2014 to 2016 were evaluated. AKI was identified by RIFLE criteria. Patients with and without AKI were compared with chi square, ANOVA, and logistic regression.

RESULTS

836 patients were 75 years old or older. Patients with AKI were more commonly male, hypotensive on admission with a greater Injury Severity Score but age, diabetes, hypertension and baseline creatinine were similar. Patients with AKI had a higher mortality that did not increase with RIFLE stage. Male sex, ISS, hypotension on admission and presence of an extremity injury were independently associated with AKI by logistic regression.

CONCLUSION

AKI in elderly trauma patients is associated with magnitude of injury and shock but not pre-existing medical comorbidities and it significantly increased the risk of death.

Acute kidney injury in trauma patients admitted to the ICU: a systematic review and meta-analysis

PURPOSE

To perform a systematic review and meta-analysis of acute kidney injury (AKI) in trauma patients admitted to the intensive care unit (ICU).

METHODS

We conducted a systematic literature search of studies on AKI according to RIFLE, AKIN, or KDIGO criteria in trauma patients admitted to the ICU (PROSPERO CRD42017060420). We searched PubMed, Cochrane Database of Systematic Reviews, UpToDate, and NICE through 3 December 2018. Data were collected on incidence of AKI, risk factors, renal replacement therapy (RRT), renal recovery, length of stay (LOS), and mortality. Pooled analyses with random effects models yielded mean differences, OR, and RR, with 95% CI.

RESULTS

Twenty-four observational studies comprising 25,182 patients were included. Study quality (Newcastle-Ottawa scale) was moderate. Study heterogeneity was substantial. Incidence of post-traumatic AKI in the ICU was 24% (20-29), of which 13% (10-16) mild, 5% (3-7) moderate, and 4% (3-6) severe AKI. Risk factors for AKI were African American descent, high age, chronic hypertension, diabetes mellitus, high Injury Severity Score, abdominal injury, shock, low Glasgow Coma Scale (GCS) score, high APACHE II score, and sepsis. AKI patients had 6.0 (4.0-7.9) days longer ICU LOS and increased risk of death [RR 3.4 (2.1-5.7)] compared to non-AKI patients. In patients with AKI, RRT was used in 10% (6-15). Renal recovery occurred in 96% (78-100) of patients.

CONCLUSIONS

AKI occurred in 24% of trauma patients admitted to the ICU, with an RRT use among these of 10%. Presence of AKI was associated with increased LOS and mortality, but renal recovery in AKI survivors was good.

Pathophysiology of Acute Illness and Injury

The pathophysiology of acute illness and injury recognizes three main effectors: infection, trauma, and ischemia-reperfusion injury. Each of them can act by itself or in combination with the other two in developing a systemic inflammatory reaction syndrome (SIRS) that is a generalized reaction to the morbid event. The time course of SIRS is variable and influenced by the number and severity of subsequent insults (e.g., reparative surgery, acquired hospital infections). It occurs simultaneously with a complex of counter-regulatory mechanisms (compensatory anti-inflammatory response syndrome, CARS) that limit the aggressive effects of SIRS. In adjunct, a progressive dysfunction of the acquired (lymphocytes) immune system develops with increased risk for immunoparalysis and associated infectious complications. Both humoral and cellular effectors participate to the development of SIRS and CARS. The most important humoral mediators are pro-inflammatory (IL-1β, IL-6, IL-8, IL-12) and anti-inflammatory (IL-4, IL-10) cytokines and chemokines, complement, leukotrienes, and PAF. Effector cells include neutrophils, monocytes, macrophages, lymphocytes, and endothelial cells. The endothelium is a key factor for production of remote organ damage as it exerts potent chemo-attracting effects on inflammatory cells, allows for leukocyte trafficking into tissues and organs, and promotes further inflammation by cytokines release. Moreover, the loss of vasoregulatory properties and the increased permeability contribute to the development of hypotension and tissue edema. Finally, the disseminated activation of the coagulation cascade causes the widespread deposition of microthrombi with resulting maldistribution of capillary blood flow and ultimately hypoxic cellular damage. This mechanism together with increased vascular permeability and vasodilation is responsible for the development of the multiple organ dysfunction syndrome (MODS).

Prevalence and risk factors for acute kidney injury among trauma patients: a multicenter cohort study

Background

Organ failure, including acute kidney injury (AKI), is the third leading cause of death after bleeding and brain injury in trauma patients. We sought to assess the prevalence, the risk factors and the impact of AKI on outcome after trauma.

Methods

We performed a retrospective analysis of prospectively collected data from a multicenter trauma registry. AKI was defined according to the risk, injury, failure, loss of kidney function and end-stage kidney disease (RIFLE) classification from serum creatinine only. Prehospital and early hospital risk factors for AKI were identified using logistic regression analysis. The predictive models were internally validated using bootstrapping resampling technique.

Results

We included 3111 patients in the analysis. The incidence of AKI was 13% including 7% stage R, 3.7% stage I and 2.3% stage F. AKI incidence rose to 42.5% in patients presenting with hemorrhagic shock; 96% of AKI occurred within the 5 first days after trauma. In multivariate analysis, prehospital variables including minimum prehospital mean arterial pressure, maximum prehospital heart rate, secondary transfer to the trauma center and data early collected after hospital admission including injury severity score, renal trauma, blood lactate and hemorrhagic shock were independent risk factors in the models predicting AKI. The model had good discrimination with area under the receiver operating characteristic curve of 0.85 (0.82–0.88) to predict AKI stage I or F and 0.80 (0.77–0.83) to predict AKI of all stages. Rhabdomyolysis severity, assessed by the creatine kinase peak, was an additional independent risk factor for AKI when it was forced into the model (OR 1.041 (1.015–1.069) per step of 1000 U/mL, p < 0.001). AKI was independently associated with a twofold increase in ICU mortality.

Conclusions

AKI has an early onset and is independently associated with mortality in trauma patients. Its prevalence varies by a factor 3 according to the severity of injuries and hemorrhage. Prehospital and early hospital risk factors can provide good performance for early prediction of AKI after trauma. Hence, studies aiming to prevent AKI should target patients at high risk of AKI and investigate therapies early in the course of trauma care.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2265-9) contains supplementary material, which is available to authorized users.

Acute kidney injury in trauma patients

PURPOSE OF REVIEW

To review epidemiology and pathophysiology of acute kidney injury (AKI) in trauma patients and propose strategies that aim at preventing AKI after trauma.

RECENT FINDINGS

AKI in trauma patients has been reported to be as frequent as 50% with an association to a prolonged length of stay and a raise in mortality. Among the specific risk factors encountered in trauma patients, hemorrhagic shock, rhabdomyolysis severity, age, and comorbidities are independently associated with AKI occurrence. Resuscitation with balanced solutes seems to have beneficial effects on renal outcome compared with NaCl 0.9%, particularly in the context of rhabdomyolysis. However, randomized clinical studies are needed to confirm this signal. Abdominal compartment syndrome (ACS) is rare but has to be diagnosed to initiate a dedicated therapy.

SUMMARY

The high incidence of AKI in trauma patients should lead to early identification of those at risk of AKI to establish a resuscitation strategy that aims at preventing AKI.

Acute Kidney Injury in Trauma Patients Admitted to Critical Care: Development and Validation of a Diagnostic Prediction Model

Acute Kidney Injury (AKI) complicating major trauma is associated with increased mortality and morbidity. Traumatic AKI has specific risk factors and predictable time-course facilitating diagnostic modelling. In a single centre, retrospective observational study we developed risk prediction models for AKI after trauma based on data around intensive care admission. Models predicting AKI were developed using data from 830 patients, using data reduction followed by logistic regression, and were independently validated in a further 564 patients. AKI occurred in 163/830 (19.6%) with 42 (5.1%) receiving renal replacement therapy (RRT). First serum creatinine and phosphate, units of blood transfused in first 24 h, age and Charlson score discriminated need for RRT and AKI early after trauma. For RRT c-statistics were good to excellent: development: 0.92 (0.88–0.96), validation: 0.91 (0.86–0.97). Modelling AKI stage 2–3, c-statistics were also good, development: 0.81 (0.75–0.88) and validation: 0.83 (0.74–0.92). The model predicting AKI stage 1–3 performed moderately, development: c-statistic 0.77 (0.72–0.81), validation: 0.70 (0.64–0.77). Despite good discrimination of need for RRT, positive predictive values (PPV) at the optimal cut-off were only 23.0% (13.7–42.7) in development. However, PPV for the alternative endpoint of RRT and/or death improved to 41.2% (34.8–48.1) highlighting death as a clinically relevant endpoint to RRT.

Cellular therapies and stem cell applications in trauma

BACKGROUND

As the leading cause of mortality in the United States, trauma management have improved drastically over the past few decades with improved resuscitation and hemorrhage control. Stem cells are being used in an attempt to augment healing from trauma.

DATA SOURCES

PubMed and ClinicalTrials.gov were searched for published and registered pre-clinical and clinical trials for the application of stem cells to AKI, ARDS, shock, infection, TBI, wound healing, and bone healing.

CONCLUSIONS

Stem cell therapy for augmentation of healing traumatic injuries appears safe, as demonstrated by completed phase I/II trials. Further large scale studies are needed to assess the clinical efficacy.

Epidemiology and Outcomes of Acute Kidney Injury in Critically Ill: Experience from a Tertiary Care Center

There is only limited information on the epidemiology and outcomes of acute kidney injury (AKI) in critically ill patients from low- and middle-income countries. This study aims to identify the etiology, short-term outcomes, and determinants of mortality in patients with AKI admitted to multiple medical and surgical Intensive Care Units (ICU's) in a tertiary care center. The study also aims to compare the clinical characteristics and outcomes of community-acquired AKI (CAAKI) and hospital-acquired AKI (HAAKI). A prospective, observational study was done from June 2013 to October 2015. All patients over 18 years with AKI admitted in various medical and surgical ICU's seeking nephrology referral were included. AKI was defined according to KDIGO criteria. The follow-up period was 30 days. A total of 236 patients were recruited from five medical and nine surgical ICU's. Majority (73.3%) were males. About 53.38% patients had CAAKI, whereas 46.61% had HAAKI. The predominant etiologies for AKI were sepsis (22.4%), trauma due to road traffic accidents (21.18%), acute abdomen (perforation, acute pancreatitis, bowel gangrene, intestinal obstruction and cholangitis) (18.64%), and cardiac diseases (10.59%). Sepsis and acute abdomen were the most common causes of CAAKI, whereas trauma and cardiac causes were the predominant causes of HAAKI (P < 0.05). Patients with HAAKI were younger, admitted in surgical units, had lower SOFA scores, lower serum creatinine, lesser need for dialysis, longer hospital stay, and earlier stages of AKI compared to patients with CAAKI (P < 0.05). The 30-day mortality was 52.54%. The mortality was not different between CAAKI and HAAKI (56.3% vs. 48.18%; relative risk = 0.86: 95% confidence interval 0.67–1.1). The mortality was similar across different stages of AKI.

Incidence and risk factors of acute kidney injury in the Japanese trauma population: A prospective cohort study

INTRODUCTION

Previous studies have reported the prevalence and risk factors of acute kidney injury (AKI) in relatively young trauma patients. The aims of this study were to identify the prevalence and risk factors of AKI among older Japanese trauma patients.

METHODS

We conducted a prospective observational study in the 8-bed intensive care unit (ICU) of a Japanese tertiary-care hospital. Participants comprised trauma patients aged 18 years or older admitted to the ICU. Our primary outcome was the incidence of AKI within 10days of admission, according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria.

RESULTS

Among 333 patients, 66 (19.8%) developed AKI (Stage 1, n=54; Stages 2, n=5; and Stage 3, n=7). Multivariate logistic regression analysis revealed that the incidence of AKI was associated with increased age (odds ratio (OR), 1.38; 95% confidence interval (CI), 1.15-1.65), male sex (OR, 2.06; 95%CI, 1.04-4.07), greater amount of red blood cell transfusions (OR, 1.61; 95%CI, 1.04-1.17), and presence of underlying chronic kidney disease (CKD) (OR, 3.97; 95%CI, 1.78-8.83). Length of stay in the ICU was significantly longer in patients with AKI (6days) than in those without (3days; p<0.001). Patients ≥65 years old were more likely to develop AKI (26.2% vs 11.6%; p<0.001). No significant differences in ICU stay (median, 4 vs 4days; p=0.70), hospital stay (median, 24 vs 21days; p=0.45), or 28-day mortality (2.1% vs 1.4%; p=0.19) were evident between age groups.

CONCLUSIONS

Approximately 20% of trauma patients developed AKI, and the elderly were more likely to develop AKI. Older age, male, greater units of red blood cell transfusions, and underlying CKD were associated with incidence of AKI.

Evaluation of acute kidney injury (AKI) with RIFLE, AKIN, CK, and KDIGO in critically ill trauma patients

PURPOSE

The aim of our study was to evaluate the effects of AKI development on mortality with four different classification systems (RIFLE, AKIN, CK, KDIGO) in critically ill trauma patients followed in the intensive care unit.

METHODS

A retrospective review of 2034 patients in our intensive care unit was conducted between July 2010 and August 2013. A total of 198 patients with primary trauma were included in the study to evaluate the development of AKI.

RESULTS

When the presence of AKI was investigated according to the four criteria (RIFLE, AKIN, CK, and KDIGO), the highest incidence of AKI was found according to the KDIGO classification (74.2%), followed by AKIN (72.2%), RIFLE (69.7%), and CK (59.1%). It was observed that more AKI developed according to KDIGO in patients with multiple trauma and thoracic trauma (p = 0.031, p = 0.029). Sixty-two (31%) of the 198 trauma patients monitored in the intensive care unit died; mortality was frequently found high in AKI stage 2 and 3 patients. According to the CK classification, there was a significant increase in mortality in patients with AKI on the first day (p = 0.045). AKI classifications by RIFLE, AKIN, CK, and KDIGO were independently associated with the risk of in-hospital death.

CONCLUSION

In this study, the presence of AKI was found to be an independent risk factor in the development of in-hospital mortality according to all classification systems (RIFLE, AKIN, CK, and KDIGO) in critically traumatic patients followed in ICU, and the compatibility between RIFLE, AKIN, and KDIGO was the highest among the classification systems.

Automated variable aortic control versus complete aortic occlusion in a swine model of hemorrhage

BACKGROUND

Future endovascular hemorrhage control devices will require features that mitigate the adverse effects of vessel occlusion. Permissive regional hypoperfusion (PRH) with variable aortic control (VAC) is a novel strategy to minimize hemorrhage and reduce the ischemic burden of complete aortic occlusion (AO). The objective of this study was to compare PRH with VAC to AO in a lethal model of hemorrhage.

METHODS

Twenty-five swine underwent cannulation of the supraceliac aorta, with diversion of aortic flow through an automated extracorporeal circuit. After creation of uncontrolled liver hemorrhage, animals were randomized to 90 minutes of treatment: Control (full, unregulated flow; n = 5), AO (no flow; n = 10), and PRH with VAC (dynamic distal flow initiated after 20 minutes of AO; n = 10). In the PRH group, distal flow rates were regulated between 100 and 300 mL/min based on a desired, preset range of proximal mean arterial pressure (MAP). At 90 minutes, damage control surgery, resuscitation, and restoration of full flow ensued. Critical care continued for 4.5 hours or until death. Hemodynamic parameters and markers of ischemia were recorded.

RESULTS

Study survival was 0%, 50%, and 90% for control, AO, and VAC, respectively (p < 0.01). During intervention, VAC resulted in more physiologic proximal MAP (84 ± 18 mm Hg vs. 105 ± 9 mm Hg, p < 0.01) and higher renal blood flow than AO animals (p = 0.02). During critical care, VAC resulted in higher proximal MAP (73 ± 8 mm Hg vs. 50 ± 6 mm Hg, p < 0.01), carotid and renal blood flow (p < 0.01), lactate clearance (p < 0.01), and urine output (p < 0.01) than AO despite requiring half the volume of crystalloids to maintain proximal MAP ≥50 mm Hg (p < 0.01).

CONCLUSION

Permissive regional hypoperfusion with variable aortic control minimizes the adverse effects of distal ischemia, optimizes proximal pressure to the brain and heart, and prevents exsanguination in this model of lethal hemorrhage. These findings provide foundational knowledge for the continued development of this novel paradigm and inform next-generation endovascular designs.

The Clinical Epidemiology and 30-Day Outcomes of Emergency Department Patients With Acute Kidney Injury

BACKGROUND

Acute kidney injury (AKI) is associated with increased mortality and dialysis in hospitalized patients but has been little explored in the emergency department (ED) setting.

OBJECTIVE

The objective of this study was to describe the risk factors, prevalence, management, and outcomes in the ED population, and to identify the proportion of AKI patients who were discharged home with no renal-specific follow-up.

DESIGN

This is a retrospective cohort study using administrative and laboratory databases.

SETTING

Two urban EDs in Vancouver, British Columbia, Canada.

PATIENTS

We included all unique ED patients over a 1-week period.

METHODS

All patients had their described demographics, comorbidities, medications, laboratory values, and ED treatments collected. AKI was defined pragmatically, based upon accepted guidelines. The cohort was then probabilistically linked to the provincial renal database to ascertain renal replacement (transplant or dialysis) and the provincial vital statistics database to obtain mortality. The primary outcome was the prevalence of AKI; secondary outcomes included (1) the proportion of AKI patients who were discharged home with no renal-specific follow-up and (2) the combined 30-day rate of death or renal replacement among AKI patients.

RESULTS

There were 1651 ED unique patients, and 840 had at least one serum creatinine (SCr) obtained. Overall, 90 patients had AKI (10.7% of ED patients with at least one SCr, 95% confidence interval [CI], 8.7%-13.1%; 5.5% of all ED patients, 95% CI, 4.4%-6.7%) with a median age of 74 and 70% male. Of the 31 (34.4%) AKI patients discharged home, 4 (12.9%) had renal-specific follow-up arranged in the ED. Among the 90 AKI patients, 11 died and none required renal replacement at 30 days, for a combined outcome of 12.2% (95% CI, 6.5%-21.2%).

LIMITATIONS

Sample sizes may be small. Nearly half of ED patients did not obtain an SCr. Many patients did not have sequential SCr testing, and a modified definition of AKI was used.

Patients with multiple traumatic amputations: An analysis of operation enduring freedom joint theatre trauma registry data

INTRODUCTION

Improvised Explosive Devices (IED) are the primary wounding mechanism for casualties in Operation Enduring Freedom. Patients can sustain devastating traumatic amputations, which are unlike injuries seen in the civilian trauma sector. This is a database analysis of the largest patient registry of multiple traumatic amputations.

METHODS

The Joint Theater Trauma Registry was queried for patients with a traumatic amputation from 2009 to 2012. Data obtained included the Injury Severity Score (ISS), Glasgow Coma Score (GCS), blood products, transfer from theatre, and complications including DVT, PE, infection (Acinetobacter and fungal), acute renal failure, and rhabdomyolysis. Comparisons were made between number of major amputations (1-4) and specific outcomes using χ² and Pearson's rank test, and multivariable logistic regression was performed for 30-day survival. Significance was considered with p<0.05.

RESULTS

We identified 720 military personnel with at least one traumatic amputation: 494 single, 191 double, 32 triple, and 3 quad amputees. Average age was 24.3 years (18-46), median ISS 24 (9-66), and GCS 15 (3-15). Tranexamic acid (TXA) was administered in 164 patients (23%) and tourniquets were used in 575 (80%). Both TXA and tourniquet use increased with increasing number of amputations (p<0.001). Average transfusion requirements (in units) were packed red blood cells (PRBC) 18.6 (0-142), fresh frozen plasma (FFP) 17.3 (0-128), platelets 3.6 (0-26), and cryoprecipitate 5.6 (0-130). Transfusion of all blood products increased with the number of amputations (p<0.001). All complications tested increased with the number of amputations except Acinetobacter infection, coagulopathy, and compartment syndrome. Transfer to higher acuity facilities was achieved in 676 patients (94%).

CONCLUSION

Traumatic amputations from blast injuries require significant blood product transfusion, which increases with the number of amputations. Most complications also increase with the number of amputations. Despite high injury severity, 94% of traumatic amputation patients who are alive upon admission to a role II/III facility will survive to transfer to facilities with higher acuity care.

Cellular Therapies in Trauma and Critical Care Medicine: Forging New Frontiers

Trauma is a leading cause of death in both military and civilian populations worldwide. Although medical advances have improved the overall morbidity and mortality often associated with trauma, additional research and innovative advancements in therapeutic interventions are needed to optimize patient outcomes. Cell-based therapies present a novel opportunity to improve trauma and critical care at both the acute and chronic phases that often follow injury. Although this field is still in its infancy, animal and human studies suggest that stem cells may hold great promise for the treatment of brain and spinal cord injuries, organ injuries, and extremity injuries such as those caused by orthopedic trauma, burns, and critical limb ischemia. However, barriers in the translation of cell therapies that include regulatory obstacles, challenges in manufacturing and clinical trial design, and a lack of funding are critical areas in need of development. In 2015, the Department of Defense Combat Casualty Care Research Program held a joint military–civilian meeting as part of its effort to inform the research community about this field and allow for effective planning and programmatic decisions regarding research and development. The objective of this article is to provide a “state of the science” review regarding cellular therapies in trauma and critical care, and to provide a foundation from which the potential of this emerging field can be harnessed to mitigate outcomes in critically ill trauma patients.

Acute Kidney Injury in Critically Injured Combat Veterans: A Retrospective Cohort Study

BACKGROUND

Acute kidney injury (AKI) has been associated with mortality after traumatic injury. However, there is a paucity of data for military service members with injuries received in combat. We sought to identify risk factors for AKI after combat trauma and evaluate whether AKI is a predictor of mortality.

STUDY DESIGN

Retrospective observational study.

SETTINGS & PARTICIPANTS

US service members who were critically wounded in Iraq or Afghanistan from February 1, 2002, to February 1, 2011, and survived until evacuation to Landstuhl Regional Medical Center, Germany.

PREDICTORS

Demographic variables, vital signs, injury severity score, presence of burn injury, and mechanism of injury as defined at the time of initial injury, as well as the presence of AKI ascertained within the first 7 days using KDIGO (Kidney Disease: Improving Global Outcomes) serum creatinine criteria.

OUTCOMES

Logistic regression models were used to identify risk factors for both AKI and death.

RESULTS

Of 6,011 records, 3,807 were included for analysis after excluding patients with missing data. AKI occurred in 474 (12.5%) patients and 112 (2.9%) died. More patients with versus without AKI died (n=62 [13.1%] vs n=50 [1.5%]; P<0.001). After adjustment, AKI was a predictor of mortality (OR, 5.14; 95% CI, 3.33-7.93; P<0.001). Predictors of AKI were age, African American race, injury severity score, amputations, burns, and presenting vital signs.

LIMITATIONS

AKI diagnoses limited to creatinine-based definitions.

CONCLUSIONS

AKI predicted mortality in combat veterans injured in the wars in Iraq and Afghanistan.

Acute kidney injury following severe trauma: Risk factors and long-term outcome

BACKGROUND

The trauma patient sustains numerous potentially harmful insults that may contribute to a notable risk of acute kidney injury (AKI). The aim of this study was to investigate the incidence of and to identify risk factors for AKI in severely injured trauma patients admitted to the intensive care unit (ICU). The patients were followed up for 1 year with respect to survival and end-stage renal disease.

METHODS

Trauma patients admitted to the ICU for more than 24 hours at a Level I trauma center were included. The outcome measure was AKI diagnosed Days 2 to 7 of ICU treatment. Regression analysis was performed to identify factors associated with AKI development.

RESULTS

A quarter of the patients (103 of 413) developed AKI within the first week of ICU admission. AKI was associated with increased 30-day (17.5% vs. 5.8%) and 1-year (26.2% vs. 7.1%) mortality. Risk factors for AKI were male sex, age, nondiabetic comorbidity, diabetes mellitus, Injury Severity Score (ISS) greater than 40, massive transfusion, and volume loading with hydroxyethyl starch (HES) within the first 24 hours. Unexpectedly, sepsis before AKI onset, admission hypotension, and extensive contrast loading (>150 mL) were not associated with AKI development. None of the surviving AKI patients had developed end-stage renal disease 1 year after injury.

CONCLUSION

AKI in ICU-admitted trauma patients is a common complication with substantial mortality. Diabetes, male sex, and severe injury were strong risk factors, but age, nondiabetic comorbidity, massive transfusion, and resuscitation with HES were also associated with postinjury AKI. Based on the results of the current study, volume resuscitation with HES cannot be recommended in trauma patients.

LEVEL OF EVIDENCE

Prognostic study, level III; therapeutic study, level IV.

Early acute kidney injury in military casualties

BACKGROUND

While acute kidney injury (AKI) has been well studied in a variety of patient settings, there is a paucity of data in patients injured in the course of the recent wars in Iraq and Afghanistan. We sought to establish the rate of early AKI in this population and to define risk factors for its development.

METHODS

We combined the results of two studies performed at combat support hospitals in Afghanistan. Only US service members who required care in the intensive care unit were included for analysis. Data on age, race, sex, Injury Severity Score (ISS), first available lactate, and requirement for massive transfusion were collected. Univariate analyses were performed to identify factors associated with the subsequent development of early AKI. Multivariable Cox regression was used to adjust for potential confounders.

RESULTS

The two observational cohorts yielded 134 subjects for analysis. The studies had broadly similar populations but differed in terms of age and need for massive transfusion. The rate of early AKI in the combined cohort was 34.3%, with the majority (80.5%) occurring within the first two hospital days. Patients with AKI had higher unadjusted mortality rates than those without AKI (21.7% vs. 2.3%, p < 0.001). After adjustment, ISS (hazard ratio, 1.02; 95% confidence interval, 1.00-1.03; p = 0.046) and initial lactate (hazard ratio, 1.16; 95% confidence interval, 1.03-1.31; p = 0.015) were independently associated with the development of AKI.

CONCLUSION

AKI is common in combat casualties enrolled in two prospective intensive care unit studies, occurring in 34.3%, and is associated with crude mortality. ISS and initial lactate are independently associated with the subsequent development of early AKI.

LEVEL OF EVIDENCE

Prognostic and epidemiologic study, level III.

Cystatin C is a moderate predictor of acute kidney injury in the early stage of traumatic hemorrhagic shock

Patients with traumatic hemorrhagic shock are highly susceptible to the development of acute kidney injury (AKI), but little data are available regarding the changes in cystatin C (CysC) in patients with traumatic hemorrhagic shock. The aim of the present study, therefore, was to investigate whether CysC has a higher value than serum creatinine (SCr) and urea for use in monitoring glomerular function in traumatic hemorrhagic shock. Data from a cohort of patients with traumatic hemorrhagic shock, who had been admitted to a trauma center, were collected. Receiver operating characteristic (ROC) curve analysis was used to determine the diagnostic value of serum CysC, SCr and urea for the identification of renal dysfunction, and the data were expressed as the area under the curve (AUC). CysC was not significantly affected by gender, age, mechanism of injury or time between injury and arrival at the center in the patients with traumatic hemorrhagic shock. The CysC level of the patients was significantly higher than that of the normal subjects (1.10±0.36 vs. 0.91±0.34 mg/l); the SCr and urea levels of the patients were also significantly increased compared with those of the normal subjects. Nonparametric ROC plots of the sensitivity and specificity of SCr, CysC and urea for the detection of AKI revealed AUC values of 0.901 [95% confidence interval (CI), 0.791-1.000], 0.728 (95% CI, 0.570-0.886) and 0.709 (95% CI, 0.552-0.865) for SCr, CysC and urea, respectively. No significant correlation between mortality and CysC, SCr or urea was found. These data indicate that the level of CysC is significantly increased in the early stage of traumatic hemorrhagic shock and that CysC can be used as a marker to predict AKI; however, the diagnostic utility of CysC remains lower than that of SCr in the early stage of the condition.

Acute kidney injury in an intensive care unit of a general hospital with emergency room specializing in trauma: an observational prospective study

Background

Acute kidney injury (AKI) is common among intensive care unit (ICU) patients and is associated with high mortality. Type of ICU, category of admission diagnosis, and socioeconomic characteristics of the region can impact AKI outcomes. We aimed to determine incidence, associated factors and mortality of AKI among trauma and non-trauma patients in a general ICU from a low-income area.

Methods

We studied 279 consecutive patients in an ICU during a follow-up of one year. Patients with less than 24-hour stay in the ICU and with chronic kidney disease were excluded. AKI was classified according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria in three stages. Comparisons were performed by the Student-t and Mann–Whitney tests for continuous variables, respectively with and without normal distribution. Comparisons of frequencies were carried out by the Fisher test. Multivariate logistic regression was used to test variables as predictors for AKI and death.

Results

Admission categories were proportionally divided into 51.6% of non-trauma diagnosis and 48.4% of trauma cases. Most trauma cases involved brain injury (79.5%). The overall incidence of AKI was 32.9%, distributed among the three stages: 33.7% stage 1, 29.4% stage 2 and 36.9% stage-3. Patients who developed AKI were older, had more diabetes, stayed longer in the ICU, presented higher APACHE II and more often needed mechanical ventilation and use of vasopressors. In comparison with non-trauma cases, trauma patients had a greater prevalence of males, higher APACHE II score, higher urine output, and younger age. There was no difference concerning development of AKI and crude mortality between trauma and non-trauma patients. Age, presence of diabetes, APACHE score and use of vasopressors were independent predictors for AKI, and AKI increased the risk of death ten-fold (OR = 14.51; CI 95% = 7.94-26.61; p < 0.001).

Conclusions

There was a high incidence of AKI in this study. AKI was strongly associated with mortality both among trauma and non-trauma patients. Trauma cases, especially brain injury due to traffic accidents involving motorized two-wheeled vehicles, should be seen as an important preventable cause of AKI.

Critical Care for the Patient With Multiple Trauma

Trauma remains the leading cause of death worldwide and the leading cause of death in those less than 44 years old in the United States. Admission to a verified trauma center has been shown to decrease mortality following a major injury. This decrease in mortality has been a direct result of improvements in the initial evaluation and resuscitation from injury as well as continued advances in critical care. As such, it is vital that intensive care practitioners be familiar with various types of injuries and their associated treatment strategies as well as their potential complications in order to minimize the morbidity and mortality frequently seen in this patient population.