Natural History and Outcomes of Renal Failure after Trauma

Predisposing Factors and Outcome of Acute Kidney Injury After Blunt Trauma: A 10-Year Study

INTRODUCTION

Acute kidney injury (AKI) indicates an impairment of the renal function following blunt trauma. It is multifactorial and associated with an increased risk of morbidity and mortality. The incidence and risk factors of AKI in young patients with trauma are not well-described. This study aimed to evaluate the incidence, clinical characteristics, and outcomes of post-traumatic AKI. We hypothesized that AKI is associated with worse outcomes in patients with trauma.

METHODS

This was a retrospective study of all adult trauma patients admitted to a level 1 trauma center between 2011 and 2021. AKI was diagnosed on the basis of the Kidney Disease Improving Global Outcomes criteria. Data were collected and analyzed for patients with and without AKI using chi-square test and Student's t-test. Multivariate logistic regression analysis and Kaplan-Meier curves were performed.

RESULTS

A total of 17,341 patients with trauma were evaluated, of which 140 (0.8%) developed AKI. Patients with AKI were older (40 ± 20 versus 32 ± 16 y), had more comorbidities, and had a higher injury severity score (ISS) and in-hospital mortality (65% versus 3.2%) than non-AKI patients. Direct trauma to the kidney was reported in only nine (6.4%) patients in the AKI group. Among patients with AKI, nonsurvivors had a higher ISS and were more likely to have hypotension, elevated serum lactate, positive troponin, and a lower platelet-to-lymphocyte ratio than survivors. Multiple logistic regression analyses showed that age, ISS, acute respiratory distress syndrome, blood transfusion, diabetes mellitus, onadmission Glasgow coma scale score, and shock index were predictors of AKI in trauma patients, whereas ISS (odds ratio (OR) = 1.05; 95% confidence interval (CI):1.003-1.100; P = 0.03), serum lactate level (OR = 1.25; 95% CI: 1.019-1.533; P = 0.03), and hypotension (OR = 3.22; 95% CI: 1.044-9.945; P = 0.04) were independent predictors of mortality in patients with posttraumatic AKI. Kaplan-Meier survival analysis showed significant differences in mortality among the three stages of AKI (P = 0.03), with the worst outcome in stage III. However, after adjusting for age, hypotension, and ISS, the Cox regression model showed that only stage I had better survival than stages II and III, whereas no survival difference was noted between stages II and III (P = 0.06).

CONCLUSIONS

AKI in young trauma patients is uncommon and associated with a prolonged hospital course and higher mortality. This study identified factors that independently predicted the development of AKI and its outcomes in patients with trauma. However, further prospective and multicenter studies are required to minimize the incidence and complications of posttraumatic AKI.

Black Race and Body Mass Index Are Risk Factors for Rhabdomyolysis and Acute Kidney Injury in Trauma

Purpose: Obesity has been shown in a single-center study to be a risk factor for rhabdomyolysis. More recently, sickle cell trait, known to be more prevalent in blacks, has been shown to be a risk factor for rhabdomyolysis. We hypothesized that in trauma patients, black race and a higher body mass index (BMI) are associated with risk for rhabdomyolysis and acute kidney injury (AKI). Materials and Methods: The National Trauma Data Bank (NTDB) was queried (2013-2015) to identify patients age ≥18 years and grouped by BMI: normal (18.5-24.99 kg/m2), underweight (16.5-18.49 kg/m2), overweight (25-29.99 kg/m2), obese (30-34.99 kg/m2), severely obese (35-39.99 kg/m2), and morbidly obese (≥40 kg/m2). A multivariable logistic regression model was used to assess whether a higher BMI or black race was associated with rhabdomyolysis or AKI. Results: After adjusting for covariates, severe obesity (odds ratio (OR) = 1.42, confidence interval (CI) = 1.01-1.99, p < .001), morbid obesity (OR = 1.46, CI = 1.04-2.06, p < .001), and black race (OR = 1.52, CI = 1.24-1.88, p < .001) were associated with higher risk for rhabdomyolysis. Patients that were overweight (OR = 1.17, CI = 1.11-1.24, p < .001), obese (OR = 1.32, CI = 1.24-1.41, p < .001), severely obese (OR = 1.72, CI = 1.59-1.86, p < .001), morbidly obese (OR = 1.77, CI = 1.64-1.92, p < .001), or black (OR = 1.31, CI = 1.24-1.38, p < .001) were associated with higher risk for AKI. Conclusions: Black race was associated with an increased risk of rhabdomyolysis as well as AKI in trauma. BMI ≥25 kg/m2 was associated with increased risk for AKI with the morbidly obese having the highest risk. BMI ≥35 kg/m2 was found to be associated with increased risk of rhabdomyolysis. Future studies should investigate the role for routine screening of these high-risk populations and other potential associated factors such as adherence to weight-based fluid resuscitation.

Presentation Coagulopathy and Persistent Acidosis Predict Complications in Orthopaedic Trauma Patients

OBJECTIVES

To evaluate the ability of measures of coagulopathy and acidosis to predict complications. We hypothesize that increased coagulopathy and acidosis over the first 60 hours of hospitalization will result in increased rates of infection and mortality.

DESIGN

Prospective, observational.

SETTING

Level 1 trauma center.

PATIENTS

Three hundred seventy-six skeletally mature patients with an Injury Severity Score greater than 16, who were surgically treated for high-energy fractures of the femur, pelvic ring, acetabulum, and/or spine.

MAIN OUTCOME MEASUREMENTS

Data included measures of acidosis, pH, lactate, and base excess, and measures of coagulopathy, Prothrombin (PT), Partial Throunboplastin Time (PTT), International Normalized Ratio (INR), and platelets. Complications including pneumonia, deep venous thrombosis, pulmonary embolism, infection, organ failure, acute renal failure, sepsis, and death were documented.

RESULTS

Acidosis was common on presentation (88.8%) and decreased over 48 hours (50.4%). Incidence of coagulopathy increased over 48 hours (16.3%-34.3%). Coagulopathy on presentation was associated with complications (54.0% vs. 27.7%) including pneumonia, acute renal failure, multiple organ failure, infection, sepsis, and death. Acidosis was associated with complications if it persisted later in the hospital course.

CONCLUSION

Coagulopathy on presentation is a stronger predictor of complications, sepsis, and death than acidosis. During the first 48 hours, unresolved acidosis increased the risk of complications and sepsis. Complications were most related to higher Injury Severity Score.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Analysis of Survival After Initiation of Continuous Renal Replacement Therapy in a Surgical Intensive Care Unit

IMPORTANCE

Continuous renal replacement therapy (CRRT) benefits patients with renal failure who are too hemodynamically unstable for intermittent hemodialysis. The duration of therapy beyond which continued use is futile, particularly in a population of patients admitted to and primarily cared for by a surgical service (hereinafter referred to as surgical patients), is unclear.

OBJECTIVE

To analyze proportions of and independent risk factors for survival to discharge after initiation of CRRT among patients in a surgical intensive care unit (SICU).

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included all patients undergoing CRRT from July 1, 2012, through January 31, 2016, in an SICU of an urban tertiary medical center. The population included patients treated before or after general surgery and patients admitted to a surgical service during inpatient evaluation and care before liver transplant. The pretransplant population was censored from further survival analysis on receipt of a transplant.

EXPOSURES

Continuous renal replacement therapy.

MAIN OUTCOMES AND MEASURES

Hospital mortality among patients in an SICU after initiation of CRRT.

RESULTS

Of 108 patients (64 men [59.3%] and 44 women [40.7%]; mean [SD] age, 62.0 [12.7] years) admitted to the SICU, 53 were in the general surgical group and 55 in the pretransplant group. Thirteen of the 22 patients in the pretransplant group who required 7 or more days of CRRT died (in-hospital mortality, 59.1%); among the 12 patients in the general surgery group who required 7 or more days of CRRT, 12 died (in-hospital mortality, 100%). In the general surgical group, each day of CRRT was associated with an increased adjusted odds ratio of death of 1.39 (95% CI, 1.01-1.90; P = .04).

CONCLUSIONS AND RELEVANCE

Continuous renal replacement therapy is valuable for surgical patients with an acute and correctable indication; however, survival decreases significantly with increasing duration of CRRT. Duration of CRRT does not correlate with survival among patients awaiting liver transplant.

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.

Post-traumatic acute kidney injury: a cross-sectional study of trauma patients

BACKGROUND

The causes of post-traumatic acute kidney injury (AKI) are multifactorial, and shock associated with major trauma has been proposed to result in inadequate renal perfusion and subsequent AKI in trauma patients. This study aimed to investigate the true incidence and clinical presentation of post-traumatic AKI in hospitalized adult patients and its association with shock at a Level I trauma center.

METHODS

Detailed data of 78 trauma patients with AKI and 14,504 patients without AKI between January 1, 2009 and December 31, 2014 were retrieved from the Trauma Registry System. Patients with direct renal trauma were excluded from this study. Two-sided Fisher's exact or Pearson's chi-square tests were used to compare categorical data, unpaired Student's t-test was used to analyze normally distributed continuous data, and Mann-Whitney's U test was used to compare non-normally distributed data. Propensity score matching with a 1:1 ratio with logistic regression was used to evaluate the effect of shock on AKI.

RESULTS

Patients with AKI presented with significantly older age, higher incidence rates of pre-existing comorbidities, higher odds of associated injures (subdural hematoma, intracerebral hematoma, intra-abdominal injury, and hepatic injury), and higher injury severity than patients without AKI. In addition, patients with AKI had a longer hospital stay (18.3 days vs. 9.8 days, respectively; P < 0.001) and intensive care unit (ICU) stay (18.8 days vs. 8.6 days, respectively; P < 0. 001), higher proportion of admission into the ICU (57.7% vs. 19.0%, respectively; P < 0.001), and a higher odds ratio (OR) of short-term mortality (OR 39.0; 95% confidence interval, 24.59-61.82; P < 0.001). However, logistic regression analysis of well-matched pairs after propensity score matching did not show a significant influence of shock on the occurrence of AKI.

DISCUSSION

We believe that early and aggressive resuscitation, to avoid prolonged untreated shock, may help to prevent the occurrence of post-traumatic AKI. However, more evidence is required to support this observation.

CONCLUSION

Compared to patients without AKI, patients with AKI presented with different injury characteristics and worse outcome. However, an association between shock and post-traumatic AKI could not be identified.

Assessment of Modification of Diet in Renal Disease Equation to Predict Reference Serum Creatinine Value in Severe Trauma Patients: Lessons From an Observational Study of 775 Cases

OBJECTIVE

We assessed the Modification of Diet in Renal Disease (MDRD) performance to predict serum creatinine (SCr) in severe trauma population and determined the best theoretical glomerular filtration rate (GFR) to use in this estimation.

BACKGROUND

Baseline SCr may be misestimated in severe trauma patients because of their specific demographic characteristics including renal hyperfiltration. However, the back-calculated MDRD equation is supposed to estimate SCr using a predetermined GFR of 75 mL/min/1.73 m.

METHODS

All severe trauma patients with a normal SCr were retrospectively included between January 2005 and January 2011. For each patient, the lowest SCr (oSCr) observed during the first week was used to estimate the GFR. The median GFR in period 1 (2005-2006) was determined. The back-calculated MDRD performance was assessed in period 2 (2007-2011) to predict oSCr by agreement, precision, and accuracy using a GFR of 75 mL/min/1.73 m (eSCr75-MDRD) or the median GFR observed in period 1 (eSCrTRAUMA-MDRD).

RESULTS

A total of 775 patients were studied: mean age, 37.7 ± 17 years; mean Injury Severity Score, 19 ± 11; 75% of male. In period 1 (n = 243), median GFR was 121 mL/min/1.73 m. In period 2 (n = 532), eSCrTRAUMA-MDRD demonstrated better agreement in predicting oSCr than eSCr75-MDRD (mean bias 2 vs 35 μmol/L; P < 0.001). Both precision (14 vs 39 μmol/L, respectively) and accuracy were significantly improved with eSCrTRAUMA-MDRD. Proportion of estimated SCr values that deviated less than 15%, 30%, or 50% was also higher with eSCrTRAUMA-MDRD (P < 0.001).

CONCLUSIONS

The eSCr75-MDRD equation systematically overestimates oSCr of severe trauma patients. The eSCrTRAUMA-MDRD equation determined was statistically superior allowing more accurate qualification of acute kidney injury.

Obesity Is Associated With More Complications and Longer Hospital Stays After Orthopaedic Trauma

OBJECTIVE

The objective of this study was to characterize relationships between obesity and initial hospital stay, including complications, in patients with multiple system trauma and surgically treated fractures.

DESIGN

Prospective, observational.

SETTING

Level 1 trauma center.

PATIENTS

Three hundred seventy-six patients with an Injury Severity Score greater than 16 and mechanically unstable high-energy fractures of the femur, pelvic ring, acetabulum, or spine requiring stabilization.

MAIN OUTCOME MEASUREMENTS

Data for obese (body mass index ≥ 30) versus nonobese patients included presence of pneumonia, deep vein thrombosis, pulmonary embolism, infection, organ failure, and mortality. Days in ICU and hospital, days on ventilator, transfusions, and surgical details were documented.

RESULTS

Complications occurred more often in obese patients (38.0% vs. 28.4%, P = 0.03), with more acute renal failure (5.70% vs. 1.38%, P = 0.02) and infection (11.4% vs. 5.50%, P = 0.04). Days in ICU and mechanical ventilation times were longer for obese patients (7.06 vs. 5.25 days, P = 0.05 and 4.92 vs. 2.90 days, P = 0.007, respectively). Mean total hospital stay was also longer for obese patients (12.3 vs. 9.79 days, P = 0.009). No significant differences in rates of mortality, multiple organ failure, or pulmonary complications were noted. Medically stable obese patients were almost twice as likely to experience delayed fracture fixation due to preference of the surgeon and were more likely to experience delay overall (26.0% vs. 16.1%; P = 0.02). Mean time from injury to fixation was 34.9 hours in obese patients versus 23.7 hours in nonobese patients (P = 0.03).

CONCLUSIONS

Obesity was noted among 42% of our trauma patients. In obese patients, complications occurred more often and hospital and ICU stays were significantly longer. These increases are likely to be associated with greater hospital costs. Surgeon decision to delay procedures in medically stable obese patients may have contributed to these findings; definitive fixation was more likely to be delayed in obese patients. Further study to optimize the care of patients with increased body mass index may help to improve outcomes and minimize additional treatment expenses.

Outcomes After Post-Traumatic AKI Requiring RRT in United States Military Service Members

BACKGROUND AND OBJECTIVES

Mortality and CKD risk have not been described in military casualties with post-traumatic AKI requiring RRT suffered in the Iraq and Afghanistan wars.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This is a retrospective case series of post-traumatic AKI requiring RRT in 51 military health care beneficiaries (October 7, 2001-December 1, 2013), evacuated to the National Capital Region, documenting in-hospital mortality and subsequent CKD. Participants were identified using electronic medical and procedure records.

RESULTS

Age at injury was 26±6 years; of the participants, 50 were men, 16% were black, 67% were white, and 88% of injuries were caused by blast or projectiles. Presumed AKI cause was acute tubular necrosis in 98%, with rhabdomyolysis in 72%. Sixty-day all-cause mortality was 22% (95% confidence interval [95% CI], 12% to 35%), significantly less than the 50% predicted historical mortality (P<0.001). The VA/NIH Acute Renal Failure Trial Network AKI integer score predicted 60-day mortality risk was 33% (range, 6%-96%) (n=49). Of these, nine died (mortality, 18%; 95% CI, 10% to 32%), with predicted risks significantly miscalibrated (P<0.001). The area under the receiver operator characteristic curve for the AKI integer score was 0.72 (95% CI, 0.56 to 0.88), not significantly different than the AKI integer score model cohort (P=0.27). Of the 40 survivors, one had ESRD caused by cortical necrosis. Of the remaining 39, median time to last follow-up serum creatinine was 1158 days (range, 99-3316 days), serum creatinine was 0.85±0.24 mg/dl, and eGFR was 118±23 ml/min per 1.73 m(2). No eGFR was <60 ml/min per 1.73 m(2), but it may be overestimated because of large/medium amputations in 54%. Twenty-five percent (n=36) had proteinuria; one was diagnosed with CKD stage 2.

CONCLUSIONS

Despite severe injuries, participants had better in-hospital survival than predicted historically and by AKI integer score. No patient who recovered renal function had an eGFR<60 ml/min per 1.73 m(2) at last follow-up, but 23% had proteinuria, suggesting CKD burden.

Incidence, clinical predictors and outcome of acute renal failure among North Indian trauma patients

Context:

There is a need for identifying risk factors aggravating development of acute renal failure after attaining trauma and defining new parameters for better assessment and management. Aim of the study was to determine the incidence of acute renal failure among trauma patients, and its correlation with various laboratory and clinical parameters recorded at the time of admission and in-hospital mortality.

Subjects and Methods:

The retrospective cohort study included admitted 208 trauma patients over a period of one year. 135 trauma patients at the serum creatinine level >2.0 mg/dL were enrolled in under the group of acute renal failure. 73 patients who had normal creatinine level made the control group. They were further assessed with clinical details and laboratory investigations.

Results:

Incidence of acute renal failure was 3.1%. There were 118 (87.4%) males and average length of stay was 9 (1, 83) days. Severity of injury (ISS, GCS) was relatively more among the renal failure group. Renal failure was transient in 35 (25.9%) patients. They had higher incidence of bone fracture (54.0%) (P= 0.04). Statistically significant association was observed between patients with head trauma and mortality 72 (59.0%) (P= 0.001). Prevalence of septic 24 (59.7%) and hemorrhagic 9 (7.4%) shock affected the renal failure group.

Conclusion:

Trauma patients at the urea level >50 mg/dL, ISS >24 on the first day of admission had 23 times and 7 times the risk of developing renal failure. Similarly, patients with hepatic dysfunction and pulmonary dysfunction were 12 times and 6 times. Patients who developed cardiovascular dysfunction, hematological dysfunction and post-trauma renal failure during the hospital stay had risk for mortality 29, 7 and 8 times, respectively. The final prognostic score obtained was: 14*hepatic dysfunction + 11*cISS + 18*cUrea + 12*cGlucose + 10*pulmonary dysfunction. Optimal score cut-off for prediction of renal failure was found to be ≥25 with specificity, sensitivity and positive likelihood ratio to be 84.9%, 78.4% and 3.9, respectively.

African American race, obesity, and blood product transfusion are risk factors for acute kidney injury in critically ill trauma patients

PURPOSE

Acute kidney injury (AKI) is a common source of morbidity after trauma. We sought to determine novel risk factors for AKI, by Acute Kidney Injury Network (AKIN) criteria, in critically ill trauma patients.

MATERIALS AND METHODS

A prospective cohort of 400 patients admitted to the intensive care unit of a level 1 trauma center was followed for the development of AKI over 5 days.

RESULTS

Acute kidney injury developed in 147 (36.8%) of 400 patients. In multivariable regression analysis, independent risk factors for AKI included African American race (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.08-3.18; P = .024), body mass index of 30 kg/m(2) or greater (OR, 4.72 versus normal body mass index; 95% CI, 2.59-8.61; P < .001), diabetes mellitus (OR, 3.26; 95% CI, 1.30-8.20; P = .012), abdominal Abbreviated Injury Scale score of 4 or more (OR, 3.78; 95% CI, 1.79-7.96; P < .001), and unmatched packed red blood cells administered during resuscitation (OR, 1.13 per unit; 95% CI, 1.04-1.23; P = .004). Acute Kidney Injury Network stages 1, 2, and 3 were associated with hospital mortality rates of 9.8%, 13.7%, and 30.4%, respectively, compared with 3.8% for those without AKI (P < .001).

CONCLUSIONS

Acute kidney injury in critically ill trauma patients is associated with substantial mortality. The findings of African American race, obesity, and blood product administration as independent risk factors for AKI deserve further study to elucidate underlying mechanisms.

Renal endocrine manifestations during polytrauma: A cause of concern for the anesthesiologist

Nowadays, an increasing number of patients get admitted with polytrauma, mainly due to road traffic accidents. These polytrauma victims may exhibit associated renal injuries, in addition to bone injuries and injuries to other visceral organs. Nevertheless, even in cases of polytrauma, renal tissue is hyperfunctional as part of the normal protective responses of the body to external insults. Both polytrauma and renal injuries exhibit widespread renal, endocrine, and metabolic responses. The situation is very challenging for the attending anesthesiologist, as he is expected to contribute immensely, not only in the resuscitation of such patients, but if required, to allow the operative procedures in case of life-threatening injuries. During administration of anesthesia, care has to be taken, not only to maintain hemodynamic stability, but equal attention has to be paid to various renal protection strategies. At the same time, various renoendocrine manifestations have to be taken into account, so that a judicious use of anesthesia drugs can be made, to minimize the renal insults.

Early appropriate care: definitive stabilization of femoral fractures within 24 hours of injury is safe in most patients with multiple injuries

BACKGROUND

Type and timing of treatment of femur fractures is controversial. Although reported as safe and effective in many reports, others have suggested that early definitive stabilization may cause complications, particularly in patients with chest and head injuries. Damage control orthopedics was proposed as an alternative in unstable patients. This study examines the effects of timing of fixation and investigates risk factors for complications.

METHODS

Seven hundred fifty patients with femur fractures treated between 1999 and 2006 were reviewed. Skeletally mature patients with mean age 35.8 years and mean Injury Severity Score (ISS) 23.7 were included. Four hundred ninety-two patients had ISS ≥18. Early stabilization (n = 656) was defined as definitive treatment of the femur fracture within 24 hours of injury.

RESULTS

Early definitive stabilization in patients with multiple injuries was associated with fewer complications than delayed stabilization (18.9% vs. 42.9%, p < 0.037) after adjusting for patient age and ISS. Early treatment was also associated with shorter hospital stay, intensive care unit stay, and ventilator days (p < 0.001). Severe (Abbreviated Injury Scale score ≥3) abdominal injury was associated with more complications than severe head (Glasgow Coma Scale score ≤8) and chest (Abbreviated Injury Scale score ≥3) injuries (44.2% vs. 40.9%, p = 0.68, and 34.4%, p = 0.024, respectively) and was an independent risk factor for complications (p < 0.0001). Chest injury was an independent risk factor for pulmonary complications (p < 0.001), but surgical delay in patients with chest injury was also associated with pulmonary complications (p = 0.04). More sepsis was noted patients with severe head injury (22.7% vs. 4.5%, p = 0.037) or severe chest injury (10.2% vs. 2.5%, p = 0.044) when treated on a delayed basis. More patients transferred from other hospitals were treated on a delayed basis (48.9% vs. 37.5%, p = 0.04).

CONCLUSIONS

Early definitive stabilization is associated with acceptably low rates of complications and is safe in most patients with multiple injuries, including some with severe abdominal, chest, or head injuries with attention to resuscitation before surgery. More complications and longer hospital stay were noted with delayed fixation after adjusting for age and ISS. Chest injury was associated with pulmonary complications; however, the presence of severe abdominal injury was the greatest risk factor for complications. Expediting access to definitive care may reduce complications and expenses.

Acute kidney injury with renal replacement therapy in trauma patients

BACKGROUND

Acute kidney injury (AKI) with renal replacement therapy (RRT) is rare in trauma patients. The primary aim of the study was to assess incidence, mortality and chronic RRT dependency in this patient group.

METHODS

Adult trauma patients with AKI receiving RRT at a regional trauma referral center over a 12-year period were retrospectively reviewed.

RESULTS

Population-based incidence of post-traumatic AKI with RRT was 1.8 persons per million inhabitants per year (p.p.m./year) [95% confidence the interval (CI) 1.5-2.1 p.p.m./year]. In trauma patients admitted to hospital, incidence was 0.5 per thousand (95% CI 0.3-0.7 per thousand) of those treated in intensive care unit (ICU), it was 8.3% (95% CI 5.9-10.8%). The median age was 46 years. Odds ratio (OR) for post-traumatic AKI requiring RRT was higher in males than in females in general population (OR 5.6, 95% CI 2.2-14.0), and in trauma patients admitted to hospital (OR 4.4, 95% CI 1.9-10.3) and ICU (OR 4.5, 95% CI 1.9-10.7). The in-hospital mortality rate was 24% (95% CI 11-37%), 3-month mortality 36% (95% CI 21-51%) and 1-year mortality 40% (95% CI 25-55%). Age was a risk factor for death after 1 year, with 57% (95% CI 7-109%) increased risk for each 10 years added. None of the survivors was dialysis-dependent 3 months or 1 year after trauma.

CONCLUSION

AKI in trauma patients requiring RRT was rare in this single-center study. More males than females were affected. Mortality was modest, and renal recovery was excellent as none of the survivors became dependent on chronic RRT.

Acute kidney injury after trauma: Prevalence, clinical characteristics and RIFLE classification

BACKGROUND

Acute kidney injury (AKI) is an uncommon but serious complication after trauma. The objective of this study was to evaluate the prevalence, clinical characteristics and outcome of AKI after trauma.

PATIENTS AND METHODS

This was a retrospective study performed from January 2006 to January 2008 in an emergency specialized hospital in Fortaleza city, northeast of Brazil. All patients with AKI admitted in the study period were included. Prevalence of AKI, clinical characteristics and outcome were investigated.

RESULTS

Of the 129 patients admitted to the intensive care unit (ICU), 52 had AKI. The mean age was 30.1 ± 19.2 years, and 79.8% were males. The main causes of AKI were sepsis in 27 cases (52%) and hypotension in 18 (34%). Oliguria was observed in 33 cases (63%). Dialysis was required for 19 patients (36.5%). Independent risk factors associated with AKI were abdominal trauma [odds ratio (OR) = 3.66, P = 0.027] and use of furosemide (OR = 4.10, P = 0.026). Patients were classified according to RIFLE criteria as Risk in 12 cases (23%), Injury in 13 (25%), Failure in 24 (46%), Loss in 1 (2%) and End-stage in 2 (4%). Overall in-hospital mortality was 95.3%. The main cause of death was sepsis (24%). Mortality was 100% among patients with AKI.

CONCLUSIONS

AKI is a fatal complication after trauma, which presented with a high mortality in the studied population. A better comprehension of factors associated with death in trauma-associated AKI is important, and more effective measures of prevention and treatment of AKI in this population are urgently needed.

Acute kidney injury in severe trauma assessed by RIFLE criteria: a common feature without implications on mortality?

Background

Acute kidney injury (AKI) has been hard to assess due to the lack of standard definitions. Recently, the Risk, Injury, Failure, Loss and End-Stage Kidney (RIFLE) classification has been proposed to classify AKI in a number of clinical settings. This study aims to estimate the frequency and levels of severity of AKI and to study its association with patient mortality and length of stay (LOS) in a cohort of trauma patients needing intensive care.

Methods

Between August 2001 and September 2007, 436 trauma patients consecutively admitted to a general intensive care unit (ICU), were assessed using the RIFLE criteria. Demographic data, characteristics of injury, and severity of trauma variables were also collected.

Results

Half of all ICU trauma admissions had AKI, which corresponded to the group of patients with a significantly higher severity of trauma. Among patients with AKI, RIFLE class R (Risk) comprised 47%, while I (Injury) and F (Failure) were, 36% and 17%, respectively. None of these patients required renal replacement therapy. No significant differences were found among these three AKI classes in relation to patient's age, gender, type and mechanism of injury, severity of trauma or mortality. Nevertheless, increasing severity of acute renal injury was associated with a longer ICU stay.

Conclusions

AKI is a common feature among trauma patients requiring intensive care. Although the development of AKI is associated with an increased LOS it does not appear to influence patient mortality.