Prophylactic furosemide in severe respiratory distress syndrome: blinded prospective study

Furosemide and Ductus Arteriosus Closure in Very-Low-Birth-Weight Preterm Infants: A Comprehensive Retrospective Study

Ductus arteriosus closure may be delayed in preterm infants, and prostaglandin, a vasodilator, can affect ductal patency. Furosemide can increase renal prostaglandin synthesis, so its net effect on patent ductus arteriosus (PDA) is uncertain. Our goal is to explore the relationship between furosemide and spontaneous ductal closure in very-low-birth-weight preterm infants. Our treatment for PDA involves fluid restriction initially and furosemide administration for hemodynamically significant PDA until closure is confirmed by the echocardiogram. We enrolled 105 infants from 1 January 2019 to 30 June 2022 and evaluated the impact of furosemide on ductal closure, including exposure duration and cumulative dose. There is no correlation between furosemide exposure and spontaneous ductal closure (p = 0.384). Furosemide exposure does not delay the postmenstrual age at which spontaneous ductal closure occurs (p = 0.558). The time for spontaneous ductal closure is positively associated with furosemide prescription days (coefficient value = 0.547, p = 0.026) and negatively with gestational age (coefficient value = -0.384, p = 0.062). The prescription of furosemide does not impact the probability or time duration of ductus arteriosus spontaneous closure. The cumulative dose of furosemide has minimal impact on ductal closure. The correlation between furosemide exposure duration and ductal patency duration is likely due to our treatment protocol, with gestational age being a significant factor.

The role of furosemide and fluid management for a hemodynamically significant patent ductus arteriosus in premature infants

A patent ductus arteriosus (PDA) in infants born premature can present significant management challenges for neonatal providers. Quantifying a hemodynamically significant PDA (hsPDA) represents the first hurdle, however, identifying the best evidence-based approach amongst conservative, pharmacologic, and/or interventional management options has proven to be even more complicated. Within the conservative arm, furosemide to reduce pulmonary edema and improve lung function has spawned several discussions given the concerns for its upregulation of prostaglandin E₂ in the kidneys and conflicting outcomes data. There remains no consensus regarding furosemide use in hsPDAs. In this perspective article, we summarize the approach to defining a hsPDA, review the current practice of furosemide use in the management of hsPDA, and suggest an approach to fluid management and diuresis to address the question: is the routine use of furosemide in hsPDA merited in current practice?

Pharmacoepidemiology of Furosemide in the Neonatal Intensive Care Unit

BACKGROUND

Furosemide is commonly used off-label in the neonatal intensive care unit (NICU), but current dosing practices vary widely.

OBJECTIVES

To describe dosing practices including route, dose, and duration of exposure to furosemide in a large number of community and tertiary NICUs across North America.

METHOD

Using the Pediatrix Medical Group Clinical Data Warehouse, we identified infants who received ≥1 dose of furosemide between 1997 and 2016. We excluded infants with incomplete dosing data. We calculated average daily furosemide dose, cumulative dose, total days of exposure, and maximum daily dose. We compared dosing between infants born at <32 weeks gestational age (GA) and ≥32 weeks GA.

RESULTS

A total of 18,572 infants had complete dosing data. The median (interquartile value) postnatal age at first exposure was 11 days (4, 26), the median maximum daily dose was 1.0 mg/kg (0.97, 1.6), the median average daily dose was 1.0 mg/kg (0.88, 1.1), and the median cumulative dose was 2.0 mg/kg (1.0, 4.5). The median total duration of exposure was 2 days (1, 4). A total of 177 (1%) infants received ≥4 mg/kg/day of furosemide. Infants born <32 weeks GA were an older age at initial furosemide exposure compared to those born ≥32 weeks GA: 19 versus 4 days, p < 0.001.

CONCLUSIONS

Most infants received short courses of furosemide within the labeled dosing parameters. Further studies are needed to assess the safety and efficacy of furosemide in the NICU.

Pharmacotherapy for the Prevention of Bronchopulmonary Dysplasia: Can Anything Compete with Caffeine and Corticosteroids?

Bronchopulmonary dysplasia (BPD) is a morbidity of prematurity with implications for respiratory and neurologic health into adulthood. Multiple risk factors contribute to the development of BPD leading to examination of various prevention strategies. The roles of systemic corticosteroids and caffeine have been addressed by the American Academy of Pediatrics. The place in therapy of other agents commonly utilized in clinical practice remains unclear. Inhaled nitric oxide has been the subject of numerous large, randomized controlled trials in preterm infants. Despite sound rationale, these trials have largely failed to document benefit, suggesting a limited role for inhaled nitric oxide therapy in the preterm population. In contrast, intramuscular vitamin A has been documented to reduce the incidence of BPD in randomized trials. However, the invasiveness and the sporadic availability of this therapy have led to decreased utilization. All macrolide antibiotics do not appear to have a similar impact on the incidence of BPD; however, azithromycin administered to infants colonized with Ureaplasma may have impact. Questions remain about the optimal dosing approach and long-term safety of this intervention. Finally, diuretic therapy is widely used in clinical practice despite significant toxicities and limited data supporting a role in BPD prevention. Taken together, available data suggest that caffeine and selective use of corticosteroids remain the mainstays of pharmacologic BPD prevention.

Unexpected extra-renal effects of loop diuretics in the preterm neonate

The loop diuretics furosemide and bumetanide are commonly used in neonatal intensive care units (NICUs). Furosemide, because of its actions on the ubiquitous Na(+) -K(+) -2Cl(-) isoform cotransporter and its promotion of prostanoid production and release, also has non-diuretic effects on vascular smooth muscle, airways, the ductus arteriosus and theoretically the gastrointestinal tract. Loop diuretics also affect the central nervous system through modulation of the GABA-A chloride channel.

CONCLUSION

  The loop diuretics have a variety of biological effects that are potentially harmful as well as beneficial. Care should be taken with the use of these agents because the range of their effects may be broader than the single action sought by the prescribing physician.

Neonatal diuretic therapy: furosemide, thiazides, and spironolactone

Diuretics are commonly used to treat infants with oxygen-dependent chronic lung disease. However, there are limited data suggesting a beneficial effect of long-term diuretic therapy on pulmonary function or clinical outcome in this population. Furthermore, data available for review were primarily obtained before the widespread use of antenatal steroids or surfactant replacement therapy, before recognition of the new bronchopulmonary dysplasia. If used in this population, limitations of diuretic therapy as well as significant side effects need to be understood and a rationale approach to clinical use developed on a patient-centered basis.

Diuretics for respiratory distress syndrome in preterm infants

BACKGROUND

Lung edema may complicate respiratory distress syndrome (RDS) in preterm infants.

OBJECTIVES

The aim of this review was to assess the risks and benefits of diuretic administration in preterm infants with RDS.

SEARCH METHODS

The standard search method of the Cochrane Neonatal Review Group was used. The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE and EMBASE were searched. These searches were updated in April 2003, March 2007, January 2011. In addition, the abstract books of the American Thoracic Society and Society for Pediatric Research were searched. MEDLINE and CENTRAL search was conducted using the keyword "Respiratory Distress Syndrome" alone, to find studies of medications recently classified as diuretics, such as theophylline. In addition, EMBASE, controlled-trials.com and clinicaltrials.gov searches were completed in January 2011. MEDLINE search updated to August 2011.

SELECTION CRITERIA

Trials were included in which preterm infants with RDS and less than five days of age were randomly allocated to diuretic administration. Of those trials, studies were only included in which at least one of the following outcomes measures was evaluated: mortality, patent ductus arteriosus, hypovolemic shock, intraventricular hemorrhage, renal failure, duration of oxygen supplementation, duration of mechanical ventilation, need for oxygen supplementation at 28 days of life, oxygen supplementation at 36 weeks of postmenstrual age (gestational age + postnatal age), length of stay, number of rehospitalizations during the first year of life, and neurodevelopmental outcome.

DATA COLLECTION AND ANALYSIS

The standard method for the Cochrane Collaboration, which is described in the Cochrane Collaboration Handbook, was used. Two investigators extracted, assessed and coded separately all data for each study. Any disagreement was resolved by discussion.

MAIN RESULTS

Seven studies met inclusion criteria. Six studies using furosemide were done before the current era of prenatal steroids, surfactant and fluid restriction. Furosemide administration had no long-term benefits. Furosemide-induced transient improvement in pulmonary function did not outweigh an increased risk for patent ductus arteriosus and for hemodynamic instability. In one recent study, theophylline had no long-term benefits. Theophylline significantly decreased the risk of oligoanuria and transiently increased renal function, but did not significantly affect renal function at discharge or other outcomes.

AUTHORS' CONCLUSIONS

There are no data to support routine administration of furosemide in preterm infants with RDS. Elective administration of furosemide to any patient with RDS should be carefully weighed against the risk of precipitating hypovolemia or developing a symptomatic patent ductus arteriosus. There are not enough data to support routine administration of low-dose theophylline in preterm infants with RDS.

In vivo dilatation of the ductus arteriosus induced by furosemide in the rat

Furosemide increases prostaglandin production and may be associated with patent ductus arteriosus (PDA). We aimed to clarify the in vivo ductus-dilating effects of furosemide in neonatal rats. Near-term rat pups delivered by a cesarean section were housed at 33 degrees C. After a rapid whole-body freezing, the DA diameter was measured using a microscope and a micrometer. Pregnant rats (gestational day 21) were s.c. injected with furosemide 4 h before delivery, and the neonatal DA was examined 0, 15, 30, 60, and 120 min after birth. Furosemide was also s.c. injected into 60-min-old rats and the DA diameter was examined 30, 60, and 120 min later. The control rats showed a rapid postnatal DA constriction (diameter: 0.80 and 0.08 mm at 0 and 60 min after birth, respectively). Prenatally administered furosemide delayed postnatal DA closure (0.36 mm at 60 min after birth). Furosemide injection in 60-min-old rats dilated the constricted DA at 60 min (0.25 versus 0.02 mm in the controls). Indomethacin inhibited furosemide-induced DA dilatation. Furosemide delays DA closure and dilates the constricted DA in neonatal rats. If furosemide has similar effects in human preterm neonates, caution may be warranted in its use in the treatment of infants with PDA.

Diuretics for respiratory distress syndrome in preterm infants

BACKGROUND

Lung edema may complicate respiratory distress syndrome (RDS) in preterm infants.

OBJECTIVES

The aim of this review was to assess the risks and benefits of diuretic administration in preterm infants with RDS.

SEARCH STRATEGY

The standard search method of the Cochrane Neonatal Review Group was used. MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library) were searched using the following keywords: <exp respiratory distress syndrome> and <exp diuretics>. These searches were updated in April 2003 and March 2007. In addition, the abstract books of the American Thoracic Society and Society for Pediatric Research were searched. A MEDLINE and CENTRAL search was conducted in March 2007 using the keyword "Respiratory Distress Syndrome" alone, to make sure to find studies medications recently classified as diuretics, such as theophylline.

SELECTION CRITERIA

Trials were included in which preterm infants with RDS and less than 5 days of age were randomly allocated to diuretic administration. Of those trials, studies were only included in which at least one of the following outcomes measures was evaluated: mortality, patent ductus arteriosus, hypovolemic shock, intraventricular hemorrhage, renal failure, duration of oxygen supplementation, duration of mechanical ventilation, need for oxygen supplementation at 28 days of life, oxygen supplementation at 36 weeks of postmenstrual age (gestational age + postnatal age), length of stay, number of rehospitalizations during the first year of life, and neurodevelopmental outcome.

DATA COLLECTION AND ANALYSIS

The standard method for the Cochrane Collaboration, which is described in the Cochrane Collaboration Handbook, was used. Two investigators extracted, assessed and coded separately all data for each study. Any disagreement was resolved by discussion.

MAIN RESULTS

Seven studies met inclusion criteria. Six studies using furosemide were done before the current era of prenatal steroids, surfactant and fluid restriction. Furosemide administration had no long-term benefits. Furosemide-induced transient improvement in pulmonary function did not outweigh an increased risk for patent ductus arteriosus and for hemodynamic instability. In one recent study, theophylline had no long-term benefits. Theophylline significantly decreased the risk of oligoanuria and transiently increased renal function, but did not significantly affect renal function at discharge or other outcomes.

AUTHORS' CONCLUSIONS

There are no data to support routine administration of furosemide in preterm infants with RDS. Elective administration of furosemide to any patient with RDS should be carefully weighed against the risk of precipitating hypovolemia or developing a symptomatic patent ductus arteriosus. There are not enough data to support routine administration of low-dose theophylline in preterm infants with RDS.

Diuretics in pediatrics : current knowledge and future prospects

This review summarizes current knowledge on the pharmacology, pharmacokinetics, pharmacodynamics, and clinical application of the most commonly used diuretics in children. Diuretics are frequently prescribed drugs in children. Their main indication is to reduce fluid overload in acute and chronic disease states such as congestive heart failure and renal failure. As with most drugs used in children, optimal dosing schedules are largely unknown and empirical. This is undesirable as it can potentially result in either under- or over-treatment with the possibility of unwanted effects. The pharmacokinetics of diuretics vary in the different pediatric age groups as well as in different disease states. To exert their action, all diuretics, except spironolactone, have to reach the tubular lumen by glomerular filtration and/or proximal tubular secretion. Therefore, renal maturation and function influence drug delivery and consequently pharmacodynamics. Currently advised doses for diuretics are largely based on adult pharmacokinetic and pharmacodynamic studies. Therefore, additional pharmacokinetic and pharmacodynamic studies for the different pediatric age groups are necessary to develop dosing regimens based on pharmacokinetic and pharmacodynamic models for all routes of administration.

Diurétiques et prématuré

Diuretics are frequently used in preterm infants in various situations such as patent ductus arteriosus, respiratory distress syndrome, bronchopulmonary dysplasia or neonatal renal insufficiency. However, the beneficial effects reported in the literature are usually transient, without any obvious effect on important parameters such as duration of oxygen dependency, ventilator dependency, length of hospital stay, long-term outcome, or mortality. Moreover, these drugs may induce water-electrolyte disorders especially when used for a long-term period. Thus, we recommend a systematic analysis of the beneficial/risk ratio before any use of these drugs.

Diuretics for respiratory distress syndrome in preterm infants

BACKGROUND

Lung edema may complicate respiratory distress syndrome (RDS) in preterm infants.

OBJECTIVES

The aim of this review was to assess the risks and benefits of diuretic administration in preterm infants with RDS.

SEARCH STRATEGY

We used the standard search method of the Cochrane Neonatal Review Group. We searched Medline, Embase and the Cochrane Controlled Trials Register from the Cochrane Library, using the following keywords: <exp respiratory distress syndrome> and <exp diuretics>. In addition, we searched the abstract books of the American Thoracic Society and Pediatric Research Societies.

SELECTION CRITERIA

We only included trials in which preterm infants with RDS and less than 5 days of age were randomly allocated to diuretic administration. Of those trials, we only included studies in which at least one of the following outcomes measures was evaluated: mortality, patent ductus arteriosus, hypovolemic shock, intraventricular hemorrhage, renal failure, duration of oxygen supplementation, duration of mechanical ventilation, need for oxygen supplementation at 28 days of life, oxygen supplementation at 36 weeks of postconceptional age (gestational age + postnatal age), length of stay, number of rehospitalizations during the first year of life, and neurodevelopmental outcome.

DATA COLLECTION AND ANALYSIS

We used the standard method for the Cochrane Collaboration which is described in the Cochrane Collaboration Handbook. Two investigators extracted, assessed and coded separately all data for each study. Any disagreement was resolved by discussion.

MAIN RESULTS

Six studies met inclusion criteria. Studies available for this systematic review were all done before the current era of prenatal steroids, surfactant, indomethacin and fluid restriction. Furosemide administration had no long-term benefits. Furosemide-induced transient improvement in pulmonary function did not outweigh an increased risk for patent ductus arteriosus and for hemodynamic instability.

REVIEWER'S CONCLUSIONS

There are no current data to support routine diuretic administration in preterm infants with RDS. Elective administration of furosemide or any diuretic to any patient with RDS should be carefully weighed against the risk of precipitating hypovolemia. In addition, elective administration of furosemide should be weighed against the risk of developing a symptomatic patent ductus arteriosus.

Changes in body water compartments with diuretic therapy in infants with chronic lung disease

The effects of diuretic therapy on body water compartments were studied in preterm infants with chronic lung disease. Gestational age of the infants ranged from 24 to 28 weeks, while the median postnatal age at the time of study was 40 days. Infants were randomized to receive furosemide (1.0 mg/kg/day) alone (n = 5) or combined with metolazone (0.2 mg/kg/day, n = 7) for 4 consecutive days. Treatment in both groups produced a significant decrease (P < 0.05) in extracellular water (ECW) without changes in plasma volume, total body water or body weight. The decrease in ECW with furosemide (503 +/- 28 to 446 +/- 19 ml/kg initial body weight) was of similar magnitude to that seen with combined furosemide plus metolazone (522 +/- 30 to 454 +/- 15 ml/kg initial body weight). Water and electrolyte intakes were similar in both groups and unchanged over the course of the study. These findings suggest that in infants with chronic lung disease, diuretic therapy induces intercompartmental shifts in body water, ultimately decreasing interstitial water while preserving PV. Only combined treatment with furosemide plus metolazone produced a significant increase in urine output, confirming the increased efficacy of combination therapy in inducing diuresis.

Comparative acute ototoxicity of loop diuretic compounds

A microelectrode was used to measure endocochlear potentials (EP) in adult chinchillas and to study the effects of a series of loop diuretics. EP was measured before, during and for several hours after the intravenous injection of the following loop diuretics: furosemide, piretanide, bumetanide, ethacrynic acid, indacrinone stereoisomers and ozolinone. The first four loop diuretics caused a substantial dose-related reduction of EP. The (-) isomer of indacrinone was found to cause a dose-related reduction of EP to a moderate degree. The (+) isomer of indacrinone and ozolinone caused very little change of EP, even in very high doses. Findings are consistent with data on the mechanism of action of these agents in the kidney.

The pharmacology and therapeutics of diuretics in the pediatric patient

Selection of appropriate diuretic therapy in children is hampered by a lack of age-specific pharmacokinetic and pharmacodynamic data, especially in premature neonates. Well-designed clinical trials in neonates, infants, and younger children are necessary prerequisites to safer and more efficacious diuretic therapy.

Pharmacology of diuretics in the newborn

Diuretics are used in various conditions with fluid overload. Their efficacy in the management of congestive heart failure is well documented. In contrast, the indication of diuretics in chronic lung disease and central nervous system disorders of the newborn have not been clearly established. Substantial pharmacologic knowledge of diuretics in the young infant remains to be described. Most investigations on diuretics in the sick newborn infant have examined furosemide. In contrast, the pharmaco-dynamics, pharmacokinetics, clinical indications, and toxicity of other diuretics used in the newborn require considerable further evaluation. Future studies using a combination of diuretics, acting at different segments of the nephron, also may provide newer therapeutic modalities to overcome or prevent the development of frequently observed tolerance to diuretics, as well as to treat refractory edema.