A controlled study of the nephrotoxicity of mezlocillin and gentamicin plus ampicillin in the neonate

Neonatal sepsis: a systematic review of core outcomes from randomised clinical trials

BACKGROUND

The lack of a consensus definition of neonatal sepsis and a core outcome set (COS) proves a substantial impediment to research that influences policy and practice relevant to key stakeholders, patients and parents.

METHODS

A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. In the included studies, the described outcomes were extracted in accordance with the provisions of the Core Outcome Measures in Effectiveness Trials (COMET) handbook and registered.

RESULTS

Among 884 abstracts identified, 90 randomised controlled trials (RCTs) were included in this review. Only 30 manuscripts explicitly stated the primary and/or secondary outcomes. A total of 88 distinct outcomes were recorded across all 90 studies included. These were then assigned to seven different domains in line with the taxonomy for classification proposed by the COMET initiative. The most frequently reported outcome was survival with 74% (n = 67) of the studies reporting an outcome within this domain.

CONCLUSIONS

This systematic review constitutes one of the initial phases in the protocol for developing a COS in neonatal sepsis. The paucity of standardised outcome reporting in neonatal sepsis hinders comparison and synthesis of data. The final phase will involve a Delphi Survey to generate a COS in neonatal sepsis by consensus recommendation.

IMPACT

This systematic review identified a wide variation of outcomes reported among published RCTs on the management of neonatal sepsis. The paucity of standardised outcome reporting hinders comparison and synthesis of data and future meta-analyses with conclusive recommendations on the management of neonatal sepsis are unlikely. The final phase will involve a Delphi Survey to determine a COS by consensus recommendation with input from all relevant stakeholders.

Antibiotic regimens for early-onset neonatal sepsis

BACKGROUND

Neonatal sepsis is a major cause of morbidity and mortality. It is the third leading cause of neonatal mortality globally constituting 13% of overall neonatal mortality. Despite the high burden of neonatal sepsis, high-quality evidence in diagnosis and treatment is scarce. Possibly due to the diagnostic challenges of sepsis and the relative immunosuppression of the newborn, many neonates receive antibiotics for suspected sepsis. Antibiotics have become the most used therapeutics in neonatal intensive care units. The last Cochrane Review was updated in 2004. Given the clinical importance, an updated systematic review assessing the effects of different antibiotic regimens for early-onset neonatal sepsis is needed.

OBJECTIVES

To assess the beneficial and harmful effects of different antibiotic regimens for early-onset neonatal sepsis.

SEARCH METHODS

We searched the following electronic databases: CENTRAL (2020, Issue 8); Ovid MEDLINE; Embase Ovid; CINAHL; LILACS; Science Citation Index EXPANDED and Conference Proceedings Citation Index - Science on 12 March 2021. We searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs comparing different antibiotic regimens for early-onset neonatal sepsis. We included participants from birth to 72 hours of life at randomisation.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed studies for inclusion, extracted data, and assessed risk of bias. We used the GRADE approach to assess the certainty of evidence. Our primary outcome was all-cause mortality, and our secondary outcomes were: serious adverse events, respiratory support, circulatory support, nephrotoxicity, neurological developmental impairment, necrotising enterocolitis, and ototoxicity. Our primary time point of interest was at maximum follow-up.

MAIN RESULTS

We included five RCTs (865 participants). All trials were at high risk of bias. The certainty of the evidence according to GRADE was very low. The included trials assessed five different comparisons of antibiotics. We did not conduct any meta-analyses due to lack of relevant data. Of the five included trials one trial compared ampicillin plus gentamicin with benzylpenicillin plus gentamicin; one trial compared piperacillin plus tazobactam with amikacin; one trial compared ticarcillin plus clavulanic acid with piperacillin plus gentamicin; one trial compared piperacillin with ampicillin plus amikacin; and one trial compared ceftazidime with benzylpenicillin plus gentamicin. None of the five comparisons found any evidence of a difference when assessing all-cause mortality, serious adverse events, circulatory support, nephrotoxicity, neurological developmental impairment, or necrotising enterocolitis; however, none of the trials were near an information size that could contribute significantly to the evidence of the comparative benefits and risks of any particular antibiotic regimen. None of the trials assessed respiratory support or ototoxicity. The benefits and harms of different antibiotic regimens remain unclear due to the lack of well-powered trials and the high risk of systematic errors.

AUTHORS' CONCLUSIONS

Current evidence is insufficient to support any antibiotic regimen being superior to another. Large RCTs assessing different antibiotic regimens in early-onset neonatal sepsis with low risk of bias are warranted.

Antibiotic regimens for late-onset neonatal sepsis

BACKGROUND

Neonatal sepsis is a major cause of morbidity and mortality. It is the third leading cause of neonatal mortality globally constituting 13% of overall neonatal mortality. Despite the high burden of neonatal sepsis, high-quality evidence in diagnosis and treatment is scarce. Due to the diagnostic challenges of sepsis and the relative immunosuppression of the newborn, many neonates receive antibiotics for suspected sepsis. Antibiotics have become the most used therapeutics in neonatal intensive care units, and observational studies in high-income countries suggest that 83% to 94% of newborns treated with antibiotics for suspected sepsis have negative blood cultures. The last Cochrane Review was updated in 2005. There is a need for an updated systematic review assessing the effects of different antibiotic regimens for late-onset neonatal sepsis.

OBJECTIVES

To assess the beneficial and harmful effects of different antibiotic regimens for late-onset neonatal sepsis.

SEARCH METHODS

We searched the following electronic databases: CENTRAL (2021, Issue 3); Ovid MEDLINE; Embase Ovid; CINAHL; LILACS; Science Citation Index EXPANDED and Conference Proceedings Citation Index - Science on 12 March 2021. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs comparing different antibiotic regimens for late-onset neonatal sepsis. We included participants older than 72 hours of life at randomisation, suspected or diagnosed with neonatal sepsis, meningitis, osteomyelitis, endocarditis, or necrotising enterocolitis. We excluded trials that assessed treatment of fungal infections.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed studies for inclusion, extracted data, and assessed risk of bias. We used the GRADE approach to assess the certainty of evidence. Our primary outcome was all-cause mortality, and our secondary outcomes were: serious adverse events, respiratory support, circulatory support, nephrotoxicity, neurological developmental impairment, necrotising enterocolitis, and ototoxicity. Our primary time point of interest was at maximum follow-up.

MAIN RESULTS

We included five RCTs (580 participants). All trials were at high risk of bias, and had very low-certainty evidence. The five included trials assessed five different comparisons of antibiotics. We did not conduct a meta-analysis due to lack of relevant data. Of the five included trials one trial compared cefazolin plus amikacin with vancomycin plus amikacin; one trial compared ticarcillin plus clavulanic acid with flucloxacillin plus gentamicin; one trial compared cloxacillin plus amikacin with cefotaxime plus gentamicin; one trial compared meropenem with standard care (ampicillin plus gentamicin or cefotaxime plus gentamicin); and one trial compared vancomycin plus gentamicin with vancomycin plus aztreonam. None of the five comparisons found any evidence of a difference when assessing all-cause mortality, serious adverse events, circulatory support, nephrotoxicity, neurological developmental impairment, or necrotising enterocolitis; however, none of the trials were near an information size that could contribute significantly to the evidence of the comparative benefits and risks of any particular antibiotic regimen. None of the trials assessed respiratory support or ototoxicity. The benefits and harms of different antibiotic regimens remain unclear due to the lack of well-powered trials and the high risk of systematic errors.

AUTHORS' CONCLUSIONS

Current evidence is insufficient to support any antibiotic regimen being superior to another. RCTs assessing different antibiotic regimens in late-onset neonatal sepsis with low risks of bias are warranted.

Risk of gentamicin toxicity in neonates treated for possible severe bacterial infection in low- and middle-income countries: Systematic Review

OBJECTIVES

To assess the risk of gentamicin toxicity and potential number of neonates exposed annually to this risk, through treatment with WHO-recommended first-line antibiotics (gentamicin with penicillin) for the 6.9 million neonates with possible serious bacterial infection (PSBI).

METHODS

Systematic literature review and assessment of the evidence using Cochrane and GRADE criteria. Meta-analysis was undertaken for pooled estimates where appropriate.

RESULTS

Eleven studies (946 neonates) were included (nine randomised controlled trials and two prospective cohort studies). Six trials reported consistently measured ototoxicity outcomes in neonates treated with gentamicin, and the pooled estimate for hearing loss was 3% (95% CI 0-7%). Nephrotoxicity could not be assessed due to variation in case definitions used. Estimates of the number of neonates potentially affected by gentamicin toxicity were not undertaken due to insufficient data.

CONCLUSION

Given wider scale-up of outpatient-based and lower-level treatment of PSBI, improved data are essential to better assess the risks from neonatal gentamicin treatment without assessment of blood levels, to maximise benefit and reduce harm.

Clinical trials in neonatal sepsis

Antibiotic licensing studies remain a problem in neonates. The classical adult clinical syndrome-based licensing studies do not apply to neonates, where sepsis is the most common infection. The main obstacle to conducting neonatal antibiotic trials is a lack of consensus on the definition of neonatal sepsis itself and the selection of appropriate endpoints. This article describes the difficulties of the clinical and laboratory definitions of neonatal sepsis and reviews the varying designs of previous neonatal sepsis trials. The optimal design of future trials of new antibiotics will need to be based on pharmacokinetic/pharmacodynamic parameters, combined with adequately powered clinical studies to determine safety and efficacy.

Renal glomerular and tubular function in neonates with perinatal problems

OBJECTIVE

To investigate perinatal risk factors that may be associated with impaired renal function during the first 2 weeks of life.

METHODS

The case notes of 150 neonates of gestational age (GA) 34-36 weeks and 494 of GA > 36 weeks were studied. Clinical risk factors were retrieved, along with indices of renal function: serum creatinine (SeCr), fractional excretion (FE) of sodium (FENa) and potassium (FEK), and the urinary calcium to creatinine ratio (UCa/UCr). Associations were identified by multiple and logistic regression analysis.

RESULTS

In infants with GA > 36 weeks, raised SeCr was related to perinatal stress, odds ratio (OR): 1.9, confidence interval (CI): 1.2-2.9, p < 0.05, and to duration of treatment with aminoglycosides (AGs) (t = 2.4, p < 0.01); FEK was associated with jaundice (t = -3.1, p < 0.01), and FENa with duration of AGs treatment (t = 2.6, p < 0.01). Full-term neonates with both hypoxic-ischemic encephalopathy (HIE) and AGs administration had an 80% increase in OR for impaired SeCr levels. In infants of GA 34-36 weeks, SeCr was related to perinatal stress (OR: 9, CI: 1.3-38, p < 0.05), FEK to jaundice (t = -2.1, p < 0.05), and FENa to duration of AGs administration (t = 2.2, p < 0.05) and antenatal steroid treatment (OR: 0.8, CI: 0.6-0.95, p < 0.05).

CONCLUSION

In neonates, renal impairment, being multifactorial in origin, may be caused by the additive effect of different perinatal factors. The strong negative relationship observed between jaundice and K excretion merits further investigation.

Tubular disorders in low birth weight neonates after prolonged antibiotic treatment

BACKGROUND

Aminoglycosides (AGs) and vancomycin (VM) are potentially nephrotoxic antibiotics and their co-administration increases the incidence of nephrotoxicity in adult patients. Their combined effects on renal function in extremely low birth weight (ELBW) infants (<1,000 g) have not been previously reported.

OBJECTIVES

Investigation of tubular disturbances in five ELBW neonates following repeated and prolonged treatment with a variety of AGs combined with VM.

RESULTS

The drug levels were maintained in the neonatal therapeutic range. Renal tubular wasting of potassium, phosphate, and calcium, along with hypokalemia, was documented in all neonates studied while associated hypophosphatemia was observed in three of the five neonates and a transient rise in serum creatinine in four. The renal disturbances resolved completely 1-2 weeks after cessation of treatment.

CONCLUSION

Renal tubular disturbances due to AG and VM treatment in ELBW neonates may be more common than they are diagnosed. Early detection and appropriate electrolyte supplementation may help to normalize serum electrolyte levels in these infants.

Antibiotic regimens for suspected late onset sepsis in newborn infants

BACKGROUND

Late onset neonatal sepsis (systemic infection after 48 hours of age) continues to be a significant cause of morbidity and mortality. Early treatment with antibiotics is essential as infants can deteriorate rapidly. It is not clear which antibiotic regimen is most suitable for initial treatment of suspected late onset sepsis.

OBJECTIVES

To compare the effectiveness and adverse effects of different antibiotic regimens for treatment of suspected late onset sepsis in newborn infants.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. This includes electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2004), MEDLINE (1966 - Dec 2004), EMBASE (1980 - Dec 2004) and CINAHL (1982 - Dec 2004), electronic abstracts of Pediatric Academic Society meetings (1996 - Dec 2004) and previous reviews including cross references (all articles referenced).

SELECTION CRITERIA

Randomised and quasi randomised controlled trials comparing different initial antibiotic regimens in neonates with suspected late onset sepsis were evaluated.

DATA COLLECTION AND ANALYSIS

Both reviewer authors screened abstracts and papers against the inclusion criteria, appraised the quality of and extracted data from papers. For dichotomous outcomes, treatment effect was expressed as relative risk and risk difference with 95% confidence intervals. NNT was calculated for outcomes for which there was a statistically significant reduction in risk difference.

MAIN RESULTS

Thirteen studies were identified as possibly eligible for inclusion. The majority of studies were excluded as they did not separate data for early and late onset infection. Two studies are still awaiting assessment. Only one small study, in 24 neonates, was included in this review. It compared beta-lactam therapy with a combination of beta lactam plus aminoglycoside. The study did not meet our prespecified criteria for good methodological quality. In babies with suspected infection there was no significant difference in mortality (RR 0.17, 95% CI 0.01 to 3.23) or treatment failure (RR 0.17, 95% CI 0.01 to 3.23). Antibiotic resistance was assessed and there were no cases in either group.

AUTHORS' CONCLUSIONS

There is inadequate evidence from randomised trials in favour of any particular antibiotic regimen for the treatment of suspected late onset neonatal sepsis. The available evidence is not of high quality. Although suspected sepsis and antibiotic use is common, quality research is required to specifically address both narrow and broad spectrum antibiotic use for late onset neonatal sepsis. Future research also needs to assess cost effectiveness and the impact of antibiotics in different settings such as developed or developing countries and lower gestational age groups.

Antibiotic regimens for suspected early neonatal sepsis

BACKGROUND

Early acquired infection may cause severe illness or death in the neonatal period. Prompt treatment with antibiotics has shown to reduce mortality. It is not clear which antibiotic regimen is suitable for treatment of presumed early neonatal sepsis.

OBJECTIVES

To compare effectiveness and adverse effects of antibiotic regimens for treatment of presumed early neonatal sepsis.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2003), MEDLINE (1966 to August 2003), EMBASE (1980 to September 2003) and ZETOC (1993 to August 2003) databases were searched for possible studies. Pharmaceutical companies were contacted for any unpublished data.

SELECTION CRITERIA

Randomised and quasi-randomised controlled studies comparing antibiotic regimens for the treatment of early neonatal sepsis (both monotherapies and combination therapies).

DATA COLLECTION AND ANALYSIS

Both reviewers screened abstracts and full reports against the inclusion criteria, appraised the quality of and extracted data from papers. For dichotomous outcomes, treatment effect was expressed as relative risk with 95% confidence interval. Meta-analysis was performed using a fixed effect model.

MAIN RESULTS

Two small studies had compared monotherapy with combination therapy. There was no significant difference in mortality, treatment failure or bacteriological resistance.

REVIEWERS' CONCLUSIONS

There is no evidence from randomised trials to suggest that any antibiotic regimen may be better than any other in the treatment of presumed early neonatal sepsis. More studies are needed to resolve this issue.

Antibiotics in neonatal infections: a review

The bacteria most commonly responsible for early-onset (materno-fetal) infections in neonates are group B streptococci, enterococci, Enterobacteriaceae and Listeria monocytogenes. Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, are the main pathogens in late-onset (nosocomial) infections, especially in high-risk patients such as those with very low birthweight, umbilical or central venous catheters or undergoing prolonged ventilation. The primary objective of the paediatrician is to identity all potential cases of bacterial disease quickly and begin antibacterial treatment immediately after the appropriate cultures have been obtained. Combination therapy is recommended for initial empirical treatment in the neonate. In early-onset infections, an effective first-line empirical therapy is ampicillin plus an aminoglycoside (duration of treatment 10 days). An alternative is ampicillin plus a third-generation cephalosporin such as cefotaxime, a combination particularly useful in neonatal meningitis (mean duration of treatment 14 to 21 days), in patients at risk of nephrotoxicity and/or when therapeutic monitoring of aminoglycosides is not possible. Another potential substitute for the aminoglycoside is aztreonam. Triple combination therapy (such as amoxicillin plus cefotaxime and an aminoglycoside) could also be used for the first 2 to 3 days of life, followed by dual therapy after the microbiological results. In late-onset infections the combination oxacillin plus an aminoglycoside is widely recommended. However, vancomycin plus ceftazidime (+/- an aminoglycoside for the first 2 to 3 days) may be a better choice. Teicoplanin may be a substitute for vancomycin. However, the initial approach should always be modified by knowledge of the local bacterial epidemiology. After the microbiological results, treatment should be switched to narrower spectrum agents if a specific organism has been identified, and should be discontinued if cultures are negative and the neonate is in good clinical condition. Penicillins and third-generation cephalosporins are generally well tolerated in neonates. There is controversy regarding whether therapeutic drug monitoring of aminoglycosides will decrease toxicity (particularly renal damage) in neonates, and on the efficacy and safety of a single daily dose versus multiple daily doses of these drugs. Toxic effects caused by vancomycin are uncommon, but debate still exists over the need for therapeutic drug monitoring of this agent. When antibacterials are used in neonates, accurate determination of dosage is required, particularly for compounds with a low therapeutic index and in patients with renal failure. Very low birthweight infants are also particularly prone to antibacterial-induced toxicity.

Nonoliguric and oliguric acute renal failure in asphyxiated term neonates

The purpose of this study was to determine the prevalence and types of acute renal failure in asphyxiated full-term neonates and to evaluate the accuracy of an asphyxia morbidity score in predicting acute renal failure. Neonates admitted to one institution from 1990 through 1993 with a gestational age > or = 36 weeks and 5-min Apgar score < or = 6, without congenital malformations or sepsis, were studied retrospectively for acute renal failure in the 1st week of life. Acute renal failure was defined as serum creatinine > 1.5 mg/dl (133 mumol/l) with normal maternal renal function. Nonoliguric renal failure was defined as renal failure with urine output > 1 ml/kg per hour after the 1st day. An asphyxia morbidity scoring system was used to distinguish severe from moderate asphyxia. The score ranged from 0 to 9 and was based upon fetal heart rate, Apgar score at 5 min, and base deficit in the 1st h of life. The score for severe asphyxia was defined as 6-9 and for moderate asphyxia as 1-5. Sixty-six neonates fulfilled study criteria. Acute renal failure was present in 20 of 33 (61%) infants with severe asphyxia scores and 0 of 33 with moderate asphyxia scores (P < 0.0001). Acute renal failure was nonoliguric in 12 of 20 (60%), oliguric in 5 of 20 (25%) and anuric in 3 of 20 (15%). In conclusion 1) acute renal failure occurred in 61% of infants with severe asphyxia, 2) acute renal failure associated with severe asphyxia was predominantly nonoliguric and 3) an asphyxia morbidity score, which can be determined at 1 h of age, predicted acute renal failure in full-term infants with 100% sensitivity and 72% specificity.

Renal function in premature infants during aminoglycoside therapy

The effect of three different aminoglycosides on renal function was evaluated in 30 premature infants of similar gestational age who were treated within 24 h of birth with either amikacin (10 infants, group A), gentamicin (10 infants, group B) or netilmicin (10 infants, group C), for a period of 7 days. Ten infection-free premature infants of similar post-conceptional age were used as controls. Serial determinations of plasma creatinine concentration (PCr), as well as the fractional excretion of sodium (FENa), potassium, magnesium (FEMg), phosphate (FEP) and uric acid (FEUA), and the urinary excretion of calcium (UCa/UCr ratio) were assessed before, during and after treatment. During the treatment period a significant increase in FENa, FEMg and UCa/UCr was observed in group B (P < 0.05 and P < 0.01, respectively) and an increase in FENa and UCa/UCr in group C (P < 0.01) compared with controls. These disturbances were observed with trough concentrations of aminoglycosides but were accentuated at peak serum concentrations and were restored to normal 2 days after stopping therapy. In addition, a significant correlation was demonstrated between FENa, FEMg and UCa/UCr ratio in treated patients. PCr levels decreased similarly in all patient groups, but in 8 of 30 infants (27%) they remained elevated and returned to control values only 10 days after stopping therapy. Such renal functional disturbances, although transient, may result in significant electrolyte and mineral imbalance in the sick premature infant.

The dissociation between aminoglycoside serum concentrations and nephrotoxicity

Using newborn and adult rats we tested the correlation between aminoglycoside dose, resultant serum and renal cortical concentrations and nephrotoxicity evidenced by creatinine in serum and urine, N-acetylglucosaminidase and beta 2 microglobulins in urine and sphingomyelinase in renal cortical tissue. Our data reveal that aminoglycoside nephrotoxicity is clearly more evident in adult rats despite significantly lower drug serum concentrations and in the presence of substantially higher renal cortical concentrations. These data indicate that high aminoglycoside serum concentrations are not causing nephrotoxicity but rather reflect secondary body accumulation of the drug associated renal damage.