الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 214 |  |  |
| | | from | 214 | | |
Abstract
BPD is the major cause of morbidity for preterm infants. The epidemiology and pathology of BPD have changed over the past 50 years. The diagnosis of BPD is still based on the level of respiratory support required by infants at 36 weeks post menstrual age. Infants meet the diagnostic criteria if they require supplemental oxygen during the first 28 days of life and require supplemental oxygen at age 36 weeks post-menstrual age in infants less than 32 weeks GA. Exposure to conditions that lead to preterm birth and the management of prematurity may lead to permanent change of organ function and structure. Consequences of alterations in organ function may be more evident in lungs and brain and less evident in other organs, such as the kidney. Survivors of prematurity are at increased risk at later stages of their lives for development of metabolic disease and chronic renal dysfunction. AKI is characterized by the sudden onset of renal dysfunction, leading to impaired control of acid–base, electrolyte, and fluid balance. Critically ill neonates are at a high risk of developing AKI. The diagnosis of neonatal AKI is confirmed with an elevated serum SCr for GA and postnatal age or increasing SCr from previous baseline Treatment strategies of AKI remain suboptimal, and diagnosis is usually delayed. SCr based identification of AKI is not satisfactory as SCr level is unchanged until the kidneys lose 25%–50%, it may be influenced by various non-renal factors and it underestimates GFR in the first 48 hours of life as it reflects maternal kidney function. Human CysC is a low molecular weight protein, belonging to the cystatin superfamily of protease inhibitors, which is produced at a constant rate in all nucleated cells. CysC is freely filtered through the glomerular membrane, then completely reabsorbed and degraded by the proximal tubule. Serum CysC is being promoted as a more accurate estimate of neonatal GFR. Serum CysC values of premature infants appear to be independent of gestational age. In an attempt to evaluate the role of serum cystatin C in assessment of renal function and early detection of the occurrence of AKI in patients with bronchopulmonary dysplasia in order to initiate appropriate therapeutic measures, this study was conducted on 50 patients (30 males and 20 females) with GA ranging from (28w to 38w) diagnosed as patients of bronchpulmonary dysplasia admitted to NICU over a period of two years. All patients were subjected to complete history taking, clinical examination and routine laboratory investigation. Patients also were subjected to urine analysis, 24 hours urinary output monitoring. Urea, creatinine and serum cystatin C were measured twice, the first measuremrnt was at the time of diagnosis of BPD and the second one was 3 days later with estimation of creatinine based GFR and cystatin based GFR. Renal ultrasound and Doppler were done and PS, EDV and RI were measured. In this study, the weight of 14% of the patients was below the 3rd percentile while the length of 6% of the patients was below the 3rd percentile according to Fenton growth charts. In 36% of the studied group, blood pressure was above the 95th percentile of the accepted blood pressure level. At the time of diagnosis of BPD, 24 patients required NC support, categorized as grade 1 BPD, 3 patients required NIMV support and 2 patients required HFNC support, categorized as grade 2 BPD. There were 21 patients of the studied group required MV support categorized as grade 3 BPD. The fraction of inspired oxygen used ranged from 21% to 60% with the mean about 40%. The patients’ oxygen saturation ranged from 90% to 96%. As regard renal Doppler, peak systolic velocity ranged from 19.45cm/s to 42.12 cm/ sec with the mean around 28.9 cm/sec and was abnormally decreased in 6 patients. End diastolic velocity ranged from 4.33 cm/s to 11.2cm/s with the mean 8.24 cm/s and was found to be abnormally decreased in 8 patients. Resistive index ranged from 0.6 to 0.85 with the mean 0.70 and was found to be abnormally increased in 8 patients. There was statistically significant decrease in the creatinine level with mean ±SD (0.105± 0.133 mg/dl) in the second reading compared to the first reading. As a result, there was significant increase in the creatinine based GFR in the second reading if compared to the first reading with mean ± SD (5.625± 11.429 mL/min per 1.73 m2). There was statistically significant decrease in the serum cystatin C level with mean ± SD (0.168 ± 0.32 mg/l) in the second reading if compared to the first reading. There was statistically significant increase in the cystatin C based GFR in the second reading in comparison to the first reading as well with mean ± SD (6.69± 17.737 ml/min per 1.73 m2). There were 7 cases with abnormal GFR According to the first creatinine based GFR that decreased after treatment to 5 patients in the second creatinine based GFR with no statistically significance difference according to the number of cases between both measurements. There were 16 cases with abnormal GF according to the first cystatin C based GFR that decreased after treatment to 9 patients in the second cystatin C based GFR with no statistically significance difference between both measurementsl according to the number of abnormal cases in the studied group. 5 patients were classified to have AKI. There was statistically significant increase in 1st, 2nd serum creatinine, 1st and 2nd serum cystatin C levels in the AKI patients in comparison to non AKI group. On the other hand, there was statistically significant decrease in 1st, 2nd creatinine based GFR, 1st and 2nd cystatin C based GFR. There was statistically significant increase in mortality in the AKI patients if compared to non AKI patient. There was statistically significant increase in SBP, DPB and PCO2 in the AKI patients in comparison to non AKI group. Length of hospital stay ranged from 1.5 m to 8 m, with the mean equals to 2.9 m. As regard the outcome, 37 patients was discharged, 13 patients died. By comparing the outcome of the patients, blood pressure, Fio2, PCO2, PSV, RI, serum creatinine and serum cystatin C were higher in the patients who died. Length of hospital stay was longer in the patients who died as well. On the other hand urine output, creatinine based GFR and cystatin based GFR were lower in the patients who died. Regarding the levels of creatinine and cystatin C levels there was positive significant correlation between first creatinine level and first cystatin C level and a positive significant correlation between second creatinine level and second cystatin C level as well. There was positive significant correlation between second measured creatinine based GFR and second cystatin C based GFR. There were positive significant correlations between each of weight, GA and 24 hours urine collection of the studied patients and the 1st measured creatinine based GFR. On the other hand, there was negative significant correlation between o2 saturation at time of diagnosis and 1st measured creatinine based GFR. There were negative significant correlation between each of systolic blood pressure, diastolic blood pressure, peak systolic velocity, resistive index and 1st cystatin C based GFR measurements of the studied patients. There were no correlations between weight and length of the patients and 1st measured serum cyatatin C based GFR. The results of this study show that cystatin C is able to detect reduced GFR before appearance of manifestation of AKI in infants with BPD.