Diuretic therapy and acute kidney injury in preterm neonates and infants

Perioperative Neonatal Acute Kidney Injury Is Common: Risk Factors for Poor Outcomes

OBJECTIVE

 Perioperative acute kidney injury (AKI) is associated with poor patient outcomes. The epidemiology of perioperative AKI is characterized in children and to a lesser extent in neonates with cardiac disease. We hypothesized that the prevalence of noncardiac perioperative AKI in neonates is higher than in older children. We also hypothesized that certain neonatal characteristics and comorbidities increase the risk of perioperative AKI and hospital mortality. We aimed to characterize the epidemiology and risk factors of perioperative AKI in neonates undergoing noncardiac surgeries and outline the associated mortality risk factors.

STUDY DESIGN

 We performed a retrospective study of neonates ≤28 days old who underwent inpatient noncardiac surgery in 46 U.S. children's hospitals participating in the Pediatric Hospital Information System between 2016 and 2021. AKI was evaluated throughout the surgical admission encounter. AKI was defined using the International Classification of Diseases (ICD) versions 9 and 10 codes. Comorbid risk factors are chronic and longstanding diagnoses and were selected using ICD-9 and ICD-10 diagnostic and procedure codes.

RESULTS

 Perioperative AKI occurred in 10% of neonates undergoing noncardiac surgeries. Comorbidities associated with high risk of perioperative AKI included metabolic, hematologic/immunologic, cardiovascular, and renal disorders. The relative risk of mortality in perioperative AKI was highest in infants with low birthweight (relative risk = 1.49, 1.14-1.94) and those with hematologic (1.46, 1.12-1.90), renal (1.24, 1.01-1.52), and respiratory comorbidities (1.35, 1.09-1.67).

CONCLUSION

 Perioperative AKI is common in neonates undergoing noncardiac surgeries. Infants with high-risk comorbidity profiles for the development of perioperative AKI and mortality may benefit from close surveillance of their kidney function in the perioperative period. Although retrospective, the findings of our study could inform clinicians to tailor neonatal perioperative kidney care to improve short- and long-term outcomes.

KEY POINTS

· AKI is common in neonates undergoing noncardiac surgeries.. · Extremely preterm and very low birth weight neonates have the highest rates of perioperative AKI.. · Renal, hematologic, and respiratory comorbidities increase mortality risk in neonates with perioperative AKI..

Perinatal risk factors associated with acute kidney injury severity and duration among infants born extremely preterm

BACKGROUND

We evaluated time-varying perinatal risk factors associated with early (≤7 post-natal days) and late (>7 post-natal days) severe acute kidney injury (AKI) occurrence and duration.

METHODS

A secondary analysis of Preterm Erythropoietin Neuroprotection Trial data. We defined severe AKI (stage 2 or 3) per neonatal modified Kidney Disease: Improving Global Outcomes criteria. Adjusted Cox proportional hazards models were conducted with exposures occurring at least 72 h before severe AKI. Adjusted negative binomial regression models were completed to evaluate risk factors for severe AKI duration.

RESULTS

Of 923 participants, 2% had early severe AKI. In the adjusted model, gestational diabetes (adjusted HR (aHR) 5.4, 95% CI 1.1-25.8), non-steroidal anti-inflammatory drugs (NSAIDs) (aHR 3.2, 95% CI 1.0-9.8), and vancomycin (aHR 13.9, 95% CI 2.3-45.1) were associated with early severe AKI. Late severe AKI occurred in 22% of participants. Early severe AKI (aHR 2.5, 95% CI 1.1-5.4), sepsis (aHR 2.5, 95% CI 1.4-4.4), vasopressors (aHR 2.9, 95% CI 1.8-4.6), and diuretics (aHR 2.6, 95% CI 1.9-3.6) were associated with late severe AKI. Participants who had necrotizing enterocolitis or received NSAIDs had longer severe AKI duration.

CONCLUSION

We identified major risk factors for severe AKI that can be the focus of future research.

IMPACT STATEMENT

Time-dependent risk factors for severe acute kidney injury (AKI) and its duration are not well defined among infants born <28 weeks' gestation. Over 1 in 5 infants born <28 weeks' gestation experienced severe AKI, and this study identified several major time-dependent perinatal risk factors occurring within 72 h prior to severe AKI. This study can support efforts to develop risk stratification and clinical decision support to help mitigate modifiable risk factors to reduce severe AKI occurrence and duration.

Use of furosemide in preterm neonates with acute kidney injury is associated with increased mortality: results from the TINKER registry

BACKGROUND

Diuretics are commonly used in neonatal AKI with the rationale to decrease positive fluid balance in critically sick neonates. The patterns of furosemide use vary among hospitals, which necessitates the need for a well-designed study.

METHODS

The TINKER (The Indian Iconic Neonatal Kidney Educational Registry) study provides a database, spanning 14 centres across India since August 2018. Admitted neonates (≤ 28 days) receiving intravenous fluids for at least 48 h were included. Neonatal KDIGO criteria were used for the AKI diagnosis. Detailed clinical and laboratory parameters were collected, including the indications of furosemide use, detailed dosing, and the duration of furosemide use (in days).

RESULTS

A total of 600 neonates with AKI were included. Furosemide was used in 8.8% of the neonates (53/600). Common indications of furosemide use were significant cardiac disease, fluid overload, oliguria, BPD, RDS, hypertension, and hyperkalemia. The odds of mortality was higher in neonates < 37 weeks gestational age with AKI who received furosemide compared to those who did not receive furosemide 3.78 [(1.60-8.94); p = 0.003; univariate analysis] and [3.30 (1.11-9.82); p = 0.03]; multivariate logistic regression].

CONCLUSIONS

In preterm neonates with AKI, mortality was independently associated with furosemide treatment. The furosemide usage rates were higher in neonates with associated co-morbidities, i.e. significant cardiac diseases or surgical interventions. Sicker babies needed more resuscitation at birth, and died early, and hence needed shorter furosemide courses. Thus, survival probability was higher in neonates treated with long furosemide courses vs. short courses.

Positive fluid balance and diuretic therapy are associated with mechanical ventilation and mortality in preterm neonates in the first fourteen postnatal days

BACKGROUND

Fluid overload leads to poor neonatal outcomes. Diuretics may lower the rates of mechanical ventilation (MV) and mortality in neonates with fluid overload.

METHODS

This is a retrospective study of preterm neonates ≤ 36 weeks of gestational age (GA) in the first 14 postnatal days in a level IV NICU in 2014-2020. We evaluated the epidemiology of fluid balance in the first 14 postnatal days and its association with MV and mortality and studied the association of diuretics with fluid balance, MV, and mortality.

RESULTS

In 1383 included neonates, the overall median lowest and peak fluid balances were - 7.8% (IQR: - 11.7, - 4.6) and 8% (3, 16) on days 3 (2, 5) and 13 (5, 14), respectively. Fluid balance distribution varied significantly by GA. Peak fluid balance of ≥ 10% was associated with increased odds of MV on days 7 and 14 with highest odds ratios (OR) of MV in neonates with fluid balance ≥ 15%. Peak fluid balance of ≥ 15% was associated with the greatest odds of mortality. Diuretics were used more frequently in neonates with younger GA, smaller birthweight, positive fluid balance, and those on MV.

CONCLUSIONS

Positive fluid balance negatively impacts pulmonary status. The odds of MV and death increase significantly as peak fluid balance percentage increases in all GA groups. The impact of diuretics on MV and death in preterm neonates needs further evaluation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Neonatal fluid overload-ignorance is no longer bliss

Excessive accumulation of fluid may result in interstitial edema and multiorgan dysfunction. Over the past few decades, the detrimental impact of fluid overload has been further defined in adult and pediatric populations. Growing evidence highlights the importance of monitoring, preventing, managing, and treating fluid overload appropriately. Translating this knowledge to neonates is difficult as they have different disease pathophysiologies, and because neonatal physiology changes rapidly postnatally in many of the organ systems (i.e., skin, kidneys, and cardiovascular, pulmonary, and gastrointestinal). Thus, evaluations of the optimal targets for fluid balance need to consider the disease state as well as the gestational and postmenstrual age of the infant. Integration of what is known about neonatal fluid overload with individual alterations in physiology is imperative in clinical management. This comprehensive review will address what is known about the epidemiology and pathophysiology of neonatal fluid overload and highlight the known knowledge gaps. Finally, we provide clinical recommendations for monitoring, prevention, and treatment of fluid overload.

Systemic Hypertension in Infants with Bronchopulmonary Dysplasia

PURPOSE OF REVIEW

Neonatal hypertension is increasingly recognized as improvements in neonatal intensive care have led to increased survival of premature infants. Among infants with bronchopulmonary dysplasia (BPD), the rates of hypertension are much higher than the general neonatal population. However, the etiology and pathophysiology of this increased risk of hypertension in neonates with lung disease remain unclear.

RECENT FINDINGS

Among infants with bronchopulmonary dysplasia, the rates of hypertension are much higher than the general neonatal population. New studies suggest outcomes in neonates with BPD with hypertension are usually good, with resolution of hypertension in most infants with lung disease. Several potential mechanisms of hypertension in this patient population have been recently proposed. This review focuses on the recent epidemiologic data on prevalence of hypertension in neonates with bronchopulmonary dysplasia, reviews the typical clinical course, and discusses available strategies for management of infants with bronchopulmonary dysplasia that develop hypertension.

Mortality Risk Factors among Infants Receiving Dialysis in the Neonatal Intensive Care Unit

OBJECTIVES

To identify risk factors associated with mortality for infants receiving dialysis in the neonatal intensive care unit (NICU).

STUDY DESIGN

In this retrospective cohort study, we extracted data from the Pediatrix Clinical Data Warehouse on all infants who received dialysis in the NICU from 1999 to 2018. Using a Cox proportional hazards model with robust SEs we estimated the mortality hazard ratios associated with demographics, birth details, medical complications, and treatment exposures.

RESULTS

We identified 273 infants who received dialysis. Median gestational age at birth was 35 weeks (interquartile values 33-37), median birth weight was 2570 g (2000-3084), 8% were small for gestational age, 41% white, and 72% male. Over one-half of the infants (59%) had a kidney anomaly; 71 (26%) infants died before NICU hospital discharge. Factors associated with increased risk of dying after dialysis initiation included lack of kidney anomalies, Black race, gestational age of <32 weeks, necrotizing enterocolitis, dialysis within 7 days of life, and receipt of paralytics or vasopressors (all P < .05).

CONCLUSION

In this cohort of infants who received dialysis in the NICU over 2 decades, more than 70% of infants survived. The probability of death was greater among infants without a history of a kidney anomaly and those with risk factors consistent with greater severity of illness at dialysis initiation.