Burden and etiopathogenesis of acute kidney injury in the tropics.

Acute kidney injury (AKI) is prevalent and is associated with high morbidity and mortality globally. The epidemiology differs remarkably between developing and developed economies. Infections, diarrheal illnesses, obstetric causes and nephrotoxins are very rampant in the tropics. Even though the etiologies are different, the final common pathway in the pathogenesis is similar - tubular damage or necrosis, tubular blockage, and back leak of glomerular filtrate. The mechanism of AKI in infections could be through ischemic insult consequent to hypovolemia and/or hemoglobinuria, as seen in malaria and viral hemorrhagic fevers, interstitial inflammation, or nephrotoxicity. On the contrary, the mechanism of nephrotoxin-induced AKI includes direct toxic effect on the renal tubules, intratubular precipitation of substances like djenkolic and oxalic acids (crystalluria) as well as intratubular obstruction and AKI. Toxicity could also be indirect by interacting with the pharmacokinetic profile of other coadministered medications. Bites and envenomation as well as obstetric complications also induce AKI through hypovolemia, interstitial nephritis, and other unclear mechanisms in eclampsia and preeclampsia. Outcome is variable and dependent on etiology. Prognosis appears to be significantly better in hypovolemic or prerenal and/or obstructive AKI compared to intrarenal or intrinsic AKI.

RIFLE and Acute Kidney Injury Network classifications predict mortality in leptospirosis-associated acute kidney injury.

AIM: Acute kidney injury (AKI) is a common complication in leptospirosis. The aim of this study is to investigate the association between RIFLE and AKIN classifications with mortality in leptospirosis-associated AKI. METHODS: A retrospective study was conducted in patients with leptospirosis admitted to tertiary hospitals in Brazil. The association between RIFLE and AKIN classifications with mortality was investigated. Univariate and multivariate analysis was performed to investigate risk factors for death. RESULTS: A total of 287 patients were included, with an average age of 37 ± 16 years, and 80.8% were male. Overall mortality was 13%. There was a significant association between these classifications and death. Among non-survivors, 86% were in the class 'failure' and AKIN 3. Increased mortality was observed according to the worse classifications: 'risk' (R; 2%), 'injury' (I; 8%) and 'failure' (F; 23%), as well as in AKIN 1 (2%), AKIN 2 (8%) and AKIN 3 (23%) (P < 0.0001). The worst classifications were significantly associated with death: RIFLE F (odds ratio = 11.6, P = 0.018) and AKIN 3 (odds ratio = 12.8, P = 0.013). Receiver-operator curve for patients with AKI showed high areas under the curve (0.71, 95% confidence interval = 0.67-0.74) for both RIFLE and AKIN classifications in determining the sensitivity for mortality. CONCLUSION: There is a significant association between RIFLE and AKIN classifications with mortality in patients with leptospirosis. Initiation of dialysis in patients with RIFLE F and AKIN 3 should always be considered.

Assessment of febrile illness in the returned traveller.

BACKGROUND: Fever is among the most frequently reported problems in returning travellers. OBJECTIVE: This article provides an overview of the general approach to fever in the returned traveller, including identification of common causes and management. DISCUSSION: The returned traveller may present with fever and it is important to exclude life threatening conditions such as malaria that may be related to the travel. A complete risk assessment should be undertaken, including a complete travel history, examination and further investigations, to help to narrow the differential diagnosis. Common tropical diseases found include malaria, dengue, enteric fever, rickettsial infections and respiratory infections. General practitioners should be alert to the public health implications of travel related diseases.