Year: 2019
Type: dissertation
Study design: Observational Study
Abstract: Severe burn injury is one of the most devastating traumas with its direct tissue destruction, triggering a systemic inflammation and numerous cytokine-mediated alterations of homeostasis. Acute kidney injury (AKI) is a common sequela in severe burns and substantially increases the risk of death. Known risk factors for the development of AKI are the size of the burn area, age, simultaneous inhalation injury, sepsis and use of nephrotoxic antibiotics. Early AKI develops often from a lack of sufficient kidney perfusion due to insufficient circulation or from rhabdomyolysis. Late onset AKI is often part of multiple organ failure (MOF), which is a gradually progressing, poorly manageable state. MOF is characterized by abruption in coagulation, oxygenation of lungs and kidney function. The focus of this thesis was to investigate novel biomarkers of AKI: neutrophil gelatinase-associated lipocalin (NGAL) (I) and N-terminal pro-brain natriuretic peptide (NT-proBNP) (II) in primary diagnostics of AKI. The thesis also investigated the risk factors for AKI development after severe burn injury and factors affecting the outcome (III), as well the need for long-term renal replacement therapy (RRT) after severe burn injury and possible association of burn injury and cause of death (COD) (IV). Studies I and II enrolled 19 consecutive patients treated at Helsinki Burn Centre between March 2013 and September 2014. Plasma NGAL levels elevated over time in the majority of patients. Out of 19 patients, 17 showed elevated plasma NGAL levels (>150 ng/ml). Two patients showed high NGAL levels (>600ng/ml) without AKI. The area under the curve (AUC) was 0.62 in predicting AKI during the first week after a burn injury, whereas serum creatinine (SCr) and cystatin C (CysC) showed notably better diagnostic accuracy. A multivariable regression model showed that the NTproBNP was correlated with the volume of infused fluids and age but found a negative correlation between the body mass index (BMI) and NT-proBNP levels. NT-proBNP increased over time in all patients. The variation between patients was substantial, and even more variation was observed in patients who developed AKI. No association between AKI and high NT-proBNP was discovered. Study III found that 27.3% of patients developed AKI during the intensive care unit (ICU) stay, defined by an absolute SCr value of at least 120 μmol/l (1.4 mg/dl). 11.2% required RRT, and 19.8% of patients succumbed during their hospital stay. AKI patients showed 52.9% mortality compared to 7.4% of non-AKI patients. Age, TBSA%, sepsis and rhabdomyolysis were independent risk factors for AKI. The RRT had no effect on the significantly reduced mortality in AKI patients. AKI was associated with increased mortality, even in minor burns, and mortality increased substantially in major burns. The prognosis of major burns was relatively good without AKI, though the majority of patients developed AKI in major burns (>50% burned TBSA). Age, TBSA%, sepsis and rhabdomyolysis were independent risk factors for AKI. Age, TBSA% and AKI were risk factors for death during an ICU stay. AKI substantially increased the risk of death (OR of 5.97, 95% CI 2.2-16.2). Study IV included 68 burn patients who had received RRT in the Helsinki Burn Centre between November 1988 and December 2015. 52.9% of patients succumbed during their hospital stay, and 32 discharged patients remained for follow-up. The need for RRT subsided before discharge in 81.3% of survivors. 6.3% of survivors needed RRT for over three months. Two patients received RRT constantly for a total of 10.5 and 17 months, respectively. The need for RRT subsided over time in both cases. 35.7% of deaths occurred because of burns, 7.1% because of kidney failure and 57.1% of deaths occurred for any other reason. One patient developed chronic kidney disease (CKD) and succumbed during follow-up. The study showed CKD as a rare event after burn injury and RRT. It remains possible, however, that a prior burn injury may potentially enhance future development of AKI due to other reasons.
Source: Työväentutkimus Vuosikirja
Author: Rakkolainen, Ilmari
Institution: University of Helsinki
Language: English
Topic: Acute Kidney Injury Research
Subfield: Nephrology
Field: Medicine
Domain: Health Sciences
Open Access status: green
Funder: Helsingin Yliopisto
OpenAlex ID: W2982050774