Renal failure in the newly born

Prophylactic theophylline for the prevention of severe renal dysfunction in term and post-term neonates with perinatal asphyxia: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To examine the effect of prophylactic theophylline for the prevention of severe renal dysfunction in post-asphyxiated term and post-term infants.

STUDY DESIGN

Systematic review and meta-analysis of randomized controlled trials (RCTs) comparing prophylactic theophylline vs placebo in term infants following perinatal asphyxia.

RESULT

Four RCTs involving 197 infants were included in the meta-analysis. Compared with placebo, prophylactic theophylline was associated with a significant reduction in the incidence of severe renal dysfunction (pooled relative risk) using fixed-effects model was 0.38 (95% confidence interval, 0.25 to 0.57; P<0.001).

CONCLUSION

The meta-analysis provides evidence that prophylactic theophylline significantly reduce the incidence of severe renal dysfunction. However, because of the lack of information on the long-term renal and neurodevelopmental outcome and measured theophylline levels with relation to adverse effects observed, prudence with the clinical use of prophylactic theophylline is required. Additionally, the included trials were prior to the era of therapeutic hypothermia and thus inference of renal benefit in an infant undergoing hypothermia therapy cannot be made.

Acute kidney injury post neonatal asphyxia

Acute kidney injury (AKI) is a common consequence of perinatal asphyxia, occurring in up to 56% of these infants. A major difficulty in diagnosing this condition is the lack of a consensus definition of neonatal AKI, largely because of a dearth of specific measurable variables and biochemical markers. This review will discuss the current evidence regarding the epidemiology, investigation, and treatment of AKI in the asphyxiated neonate. Particular emphasis will be given to the investigation of renal function in the neonate and to potential biomarkers that may aid the clinician in the diagnosis of renal injury in this population.

Plasma creatinine rises dramatically in the first 48 hours of life in preterm infants

OBJECTIVE

Published data show that plasma creatinine falls steadily during the first 28 days of life and that creatinine levels in the neonatal period are higher in more premature infants. However, the best reference data commence on day 2 of life. The objective of this study was to document how plasma creatinine changes in the first 48 hours of life and to examine the reason for the apparently high levels of creatinine in preterm infants, compared with maternal levels.

DESIGN

A prospective observational study on a regional neonatal intensive care unit.

PATIENTS

A total of 42 preterm infants, mean gestational age of 29.4 weeks (range: 23-35), mean birth weight of 1.42 kg (.55-2.77), divided into 4 gestation groups: 23 to 26 weeks (n = 9), 27 to 29 weeks (n = 13), 30 to 32 weeks (n = 12), and 33 to 35 weeks (n = 8).

INTERVENTIONS

Measurement of plasma creatinine and urea concentration in cord blood and in serial samples taken for routine arterial blood gas analysis.

OUTCOME MEASUREMENTS

Changes in creatinine concentration with time and relationship to gestational age, birth weight, and illness severity.

RESULTS

Mean creatinine at birth was 73 micromol/L (95% confidence interval [CI]: 68-79 micromol/L). Plasma creatinine rose significantly over the first 48 hours. Mean peak creatinine in the most preterm infants (23-26 weeks) was 221 micromol/L (CI: 195-247 micromol/L). Peak plasma creatinine was inversely related to gestation (Spearman's coefficient: -.73) and birth weight (Spearman's coefficient: -.76). Significant differences in creatinine concentration were seen among different gestational groups at 24 and 48 hours of life. Peak creatinine correlated with a high Clinical Risk Index for Babies score (Spearman's coefficient:. 64). The fall in creatinine began later in more premature infants. All 38 surviving infants had normal renal function; their mean plasma creatinine at discharge was 52 micromol/L (CI: 46-58 micromol/L).

CONCLUSIONS

Rather than falling steadily from birth, creatinine rises dramatically in the first 48 hours of life, especially in infants of <30 weeks' gestation. Even large rises in creatinine in the first 48 hours may be expected and should not be used in isolation to diagnose renal failure.

Multiple organ involvement in perinatal asphyxia

OBJECTIVES

(1) To evaluate the frequency and spectrum of severity of multisystem dysfunction after perinatal asphyxia and (2) to analyze the relationship between the clinical and biochemical markers of perinatal asphyxia and multiorgan involvement.

STUDY DESIGN

Seventy-two consecutive term newborn infants with perinatal asphyxia were studied prospectively. Systematic neurologic, renal, pulmonary, cardiac, and gastrointestinal evaluations were performed. Involvement of each organ was classified as moderate or severe.

RESULTS

Involvement of one or more organs occurred in 82% of the infants; the central nervous system (CNS) was most frequently involved (72%). Severe CNS injury (7 infants) always occurred with involvement of other organs, although moderate CNS involvement was isolated in 14 infants. Renal involvement occurred in 42%, pulmonary in 26%, cardiac in 29%, and gastrointestinal in 29% of the infants; 15% neonates had renal failure and 19% had respiratory failure. The Apgar scores at 1 and 5 minutes were the only perinatal factors related to the number of organs involved and the severity of involvement; the Apgar score at 5 minutes had the stronger independent association. No relationship or organ dysfunction was found with the umbilical cord arterial blood pH, meconium-stained amniotic fluid, umbilical cord abnormalities, presentation, or type of delivery.

CONCLUSIONS

Our findings indicate that the Apgar score at 5 minutes, in infants who have other criteria for asphyxia, is the perinatal marker that may best identify infants at risk of organ dysfunction.

Haemodialysis and ultrafiltration in babies weighing under 1000 g

Until now it has not be feasible to haemodialyse babies with renal failure who weigh less than 1000 g. Three babies weighing 630, 808, and 1140 g are described. They had multiorgan failure and could not be peritoneally dialysed. They were treated with veno-venous ultrafiltration and haemodialysis using a manual syringe driven technique that required only simple equipment. This method is highly labour intensive, but can provide control of fluid volume and plasma biochemistry in these very sick infants. Their prognosis, however, is determined by the underlying cause of their renal failure, and remains poor.

Access for peritoneal dialysis in neonates and infants

A new catheter for peritoneal dialysis in neonates and infants was used on 28 occasions in 17 patients. Advantages over other catheters included easy safe introduction over a guide wire, absence of early leakage of dialysate, and the ability to change the catheter without creating a second abdominal wound.