Early Predictor of Acute Kidney Injury in Newborns With Perinatal Asphyxia

Acute Kidney Injury is defined as the inability of the kidneys to excrete nitrogenous waste products and maintain fluid and electrolyte homeostasis. It is fairly common in newborn population and is a major contributor factor of neonatal mortality and morbidity.

The most common form of Acute Kidney Injury in neonates is prerenal failure due to renal hypo-perfusion or ischemia. Pre-renal failure may result in intrinsic kidney failure if it is not treated promptly. The kidneys of neonates are particularly susceptible to hypo-perfusion because of the physiologic characteristics of neonatal kidneys, including high renal vascular resistance, high plasma renin activity, low glomerular filtration, decreased intra-cortical perfusion rate and decreased reabsorption of sodium in the proximal tubules in the first days of a neonatal life. Thus, newborn infants are vulnerable to acute tubular necrosis or cortical necrosis.

The cause of Acute Kidney Injury in neonates is of multi-factorial etiology and, usually, there is one or more associated contributing factor. In most studies, perinatal asphyxia and sepsis are the most commonly associated conditions.

Perinatal asphyxia is defined as abnormal neurological incident resulting in neonatal hypoxic ischemic encephalopathy , which occurs usually due to brain hypoxia and ischemic incidents. Perinatal asphyxia can result in multi-organ dysfunction through redirection of cardiac output to maintain cerebral, cardiac, and adrenal perfusion while potentially compromising perfusion to non-vital organs including kidneys, this causing Acute Kidney Injury.

The incidence of Acute Kidney Injury after Perinatal asphyxia in term neonates was shown to be around 30% to 56%. Early detection of Acute Kidney Injury could optimize and improve patient outcomes. therefore, the use of biomarkers to predict renal damage has been of interest. Serum creatinine is the most commonly used clinical measure of renal function; however, it is a poor diagnostic marker and its utility is further questionable in neonates since kidneys undergo maturational changes in postnatal period.