Does the empiric use of vancomycin in pediatrics increase the risk for Gram-negative bacteremia?

Safety and Efficacy of Nafcillin for Empiric Therapy of Late-Onset Sepsis in the NICU

BACKGROUND AND OBJECTIVE

In 2014 at Nationwide Children's Hospital, the Neonatal Antimicrobial Stewardship Program recommended nafcillin over vancomycin for empirical therapy of possible late-onset sepsis (LOS) in infants without a history of methicillin-resistant Staphylococcus aureus colonization or infection. We report our experience with this guideline and assess its safety.

METHODS

We retrospectively reviewed all infants who received nafcillin or vancomycin for empirical treatment of possible LOS at 3 NICUs before (January 2013-May 2014) and after (January 2017-March 2019) implementation of a vancomycin reduction guideline. Safety measures included duration of blood culture positivity, recurrence of infection with the same previously identified pathogen in the 14 days after discontinuation of antibiotic therapy, and mortality.

RESULTS

Among 366 infants who received a first antibiotic course for possible LOS, 84% (95 of 113) and 25% (62 of 253) received empirical therapy with vancomycin before and after the guideline implementation, respectively, representing a 70% reduction. Nafcillin use increased by 368%. Duration of blood culture positivity did not differ before and after the guidance. In 2 infants, antibiotic therapy was restarted within 14 days of discontinuation of the initial therapy for recurrence of the same infection; both had received empirical vancomycin. Overall in-hospital mortality was 10%, and there was no difference before (9%) and after (10%) implementation of the vancomycin reduction guidance (odds ratio, 0.97).

CONCLUSIONS

Nafcillin can be a safe alternative to vancomycin for empirical therapy of LOS among NICU infants who do not have a history of methicillin-resistant S aureus infection or colonization.

[Infection prevention in neonatal intensive care units]

In diesem Beitrag werden einige Besonderheiten der Infektionsprävention bei intensivmedizinisch behandelten Früh und Neugeborenen dargestellt. Ergänzend finden sich Hinweise zum krankenhaushygienischen Management der SARS-CoV-2(„severe acute respiratory syndrome coronavirus 2“)-Pandemie und zur Antibiotic Stewardship in der neonatologischen Intensivmedizin.

Association of early life antibiotics and health outcomes: Evidence from clinical studies

Preterm infants are susceptible to infections that can rapidly progress to disastrous outcomes. Antibiotics are lifesaving, but their prolonged and inappropriate use are associated with adverse outcomes. In this review, we discuss the current status of antimicrobial use in the preterm neonatal population, and the challenges in determining the initiation, duration, and choice of antibiotics. Finally, we review the clinical studies on the potential consequences of prolonged antimicrobial exposure in prematurely born infants.

Reduction of Inappropriate Antimicrobial Prescriptions in a Tertiary Neonatal Intensive Care Unit After Antimicrobial Stewardship Care Bundle Implementation

BACKGROUND

Our objective was to evaluate the appropriateness of antibiotic prescriptions in the neonatal intensive care unit using standardized criteria and determine the effects of an antimicrobial stewardship program (ASP) on patterns of antibiotic usage.

METHODS

A retrospective audit of antibiotic use from July 2010 to June 2013 was conducted, focusing on prescriptions of vancomycin, cefotaxime, meropenem and linezolid for >3 calendar-days. We evaluated the appropriateness of each course of antibiotic treatment based on the Centers for Disease Control and Prevention 12-Step Guidelines to Prevent Antimicrobial Resistance (steps 4, 6 and 9). An ASP was introduced in August 2014, and the same audit criteria were applied to review antimicrobial use in the subsequent 12 months.

RESULTS

In the pre-ASP era, 26.3%, 12.1%, 11.4% and 0% of meropenem, cefotaxime, vancomycin and linezolid courses, respectively, were inappropriate. The most common instance of inappropriate utilization included failure to use narrow-spectrum antimicrobials when appropriate. After the introduction of ASP program, 22.2%, 7.5%, 5.4% and 0% of meropenem, cefotaxime, vancomycin and linezolid courses, respectively, were inappropriate. The numbers of inappropriate antibiotic-days/1000 days of therapy with meropenem, cefotaxime and vancomycin changed from 1.89 to 1.96 [rate ratio (RR), 1.04 (0.70-1.52)], 3.56 to 1.73 [RR, 0.49 (0.33-0.71)] and 2.70 to 1.01 [RR, 0.37 (0.22-0.60)], respectively. In subgroup analysis, very low birth weight infants (birth weight, <1500 g) showed no improvement in the rates of inappropriate antibiotic prescriptions.

CONCLUSIONS

In this study, we found that ASP initiatives can be applied in neonatal populations to reduce inappropriate antimicrobial prescriptions, though a different approach may be needed among very low birth weight infants.

Empiric antibiotic regimens for neonatal sepsis in Australian and New Zealand neonatal intensive care units

AIM

Neonatal sepsis remains an important cause of morbidity and mortality, and requires prompt empiric treatment. However, only a minority of babies who receive antibiotics for suspected sepsis have an infection. Antimicrobial exposure in infancy has important short- and long-term consequences. There is no consensus regarding empirical antimicrobial regimens.

METHODS

The study included a survey of empiric antimicrobial regimens in all tertiary neonatal intensive care units in Australia and New Zealand in 2013-2014.

RESULTS

All 27 units responded. For early-onset sepsis, all units used a combination of gentamicin with either penicillin or ampicillin. For late-onset sepsis, the frequency of units using empiric vancomycin (41%) versus empiric flucloxacillin (48%) was similar. Gestational age or the presence of a central venous catheter had little influence on using vancomycin instead of flucloxacillin. For late-onset sepsis with meningitis there was marked variation in antimicrobial combinations, with 15 different regimens described. A total of 93% used a cefotaxime-based regimen, either as monotherapy (22%) or combined with a second (22%) or third (48%) agent. For suspected necrotising enterocolitis, 89% used an aminoglycoside, metronidazole and a penicillin. Historical outbreaks of multi-resistant organisms exerted long-term influence over regimen choice.

CONCLUSIONS

There was limited use of broad-spectrum agents such as carbapenems or third-generation cephalosporins. In this region with low methicillin-resistant Staphylococcus aureus prevalence, empiric vancomycin use was common, selected for activity against coagulase-negative staphylococci. Empiric vancomycin is rarely necessary because coagulase-negative staphylococci are often contaminants and sepsis is rarely fulminant, occurring almost exclusively in extremely low birthweight infants. Implementation of appropriate, local antimicrobial policies is crucial to minimise antimicrobial exposure in this vulnerable population and halt the development of antimicrobial resistance.

Self-Setting Calcium Phosphate Cements with Tunable Antibiotic Release Rates for Advanced Antimicrobial Applications

Osteomyelitis, an infectious disease predominantly tied to poor sanitary conditions in underdeveloped regions of the world, is in need of inexpensive, easily in situ synthesizable and administrable materials for its treatment. The results of this study stem from the attempt to create one such affordable and minimally invasive therapeutic platform in the form of a self-setting, injectable cement with a tunable drug release profile, composed of only nanoparticulate hydroxyapatite, the synthetic version of the bone mineral. Cements comprised two separately synthesized hydroxyapatite powders, one of which, HAP2, was precipitated abruptly, retaining the amorphous nature longer, and the other one of which, HAP1, was precipitated at a slower rate, more rapidly transitioning to the crystalline structure. Cements were made with four different weight ratios of the two hydroxyapatite components: 100/0, 85/15, 50/50, and 0/100 with respect to HAP1 and HAP2. Both the setting and the release rates measured on two different antibiotics, vancomycin and ciprofloxacin, were controlled using the weight ratio of the two hydroxyapatite components. Various inorganic powder properties were formerly used to control drug release, but here we demonstrate for the first time that the kinetics of the mechanism of formation of a solid compound can be controlled to produce tunable drug release profiles. Specifically, it was found that the longer the precursor calcium phosphate component of the cement retains the amorphous nature of the primary precipitate, the more active it was in terms of speeding up the diffusional release of the adsorbed drug. The setting rate was, in contrast, inversely proportional to the release rate and to the content of this active hydroxyapatite component, HAP2. The empirical release profiles were fitted to a set of equations that could be used to tune the release rate to the therapeutic occasion. All of the cements loaded with vancomycin or ciprofloxacin inhibited the growth of Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli and Pseudomonas aeruginosa in both agar diffusion assays and broth dilution tests with intensities either comparable to the antibiotic per se, as in the case of ciprofloxacin, or even larger than the antibiotic alone, as in the case of vancomycin. Interestingly, even the pure cements exhibited an antibacterial effect ranging from moderate to strong, while demonstrating high levels of biocompatibility with osteoclastic RAW264.7 cells and only slightly affecting the viability of the osteoblastic MC3T3-E1 cells, in direct proportion with the amount of the more active hydroxyapatite component in the cements. This antibacterial effect was especially noticeable against Gram-negative bacteria, where the growth inhibition by the cements was comparable to or even stronger than that of the pure antibiotics. The antibiofilm assay against P. aeruginosa biofilms reiterated the antibiotic effectiveness of pure, antibiotic-free cements. That the carrier per se, composed of a nontoxic, easily prepared, bone mineral composite, can exhibit a strong antibacterial effect even in the absence of an antibiotic drug is an insight highly relevant in view of the rising resistance of an array of pathogens to traditional antibiotic therapies and the demands for the timely development of suitable alternatives.

A systematic review on the application of pharmacoepidemiology in assessing prescription drug-related adverse events in pediatrics

OBJECTIVES

To conduct a systematic review of recent case-control and cohort studies in assessing adverse drug events (ADEs) among pediatric patients aged between 0 and 18 years; to establish strengths and limitations of pharmacoepidemiology when applied in evaluating pediatric drug safety; and to identify areas of pediatric drug safety that may be suitable for future pharmacoepidemiological investigations.

METHODS

A PubMed search was conducted using a list of keywords representing drugs, adverse drug events, case control and cohort studies, and pediatric population. Selection criteria were used to extract relevant studies published from 1/1 2000 to 7/1 2006.

RESULTS

Twenty-seven studies met our criteria. Of them, 12 used a prospective cohort design. The others were either case-control (seven) or retrospective cohort (eight) studies, based on the analysis of existing databases. More than half of the studies included more than 500 subjects. Inclusion and exclusion criteria for participants in these studies were generally not very stringent. The subjects closely resembled patients in the real-world settings. The length of study follow-up ranged from 1 day to 40 years. In eight studies, the length of follow-up surpassed 5 years. Potential confounding factors were taken into consideration in all of the studies. But the database-based studies generally failed to control for some important clinical variables such as disease severity. Misclassification of drug exposures also occurred in some of these studies.

CONCLUSIONS

Despite some limitations, pharmacoepidemiology proves to be useful for assessing ADEs in pediatrics. With appropriate study design, this methodology can bolster our understanding about the safety of pediatric drug use. Several areas of pediatric drug safety may especially be suitable for future pharmacoepidemiological investigations. These areas include the safety of polypharmacy, long-term drug effects, and off-label drug use.

Risk factors for mortality resulting from bloodstream infections in a pediatric intensive care unit

BACKGROUND

Bloodstream infections (BSIs) are prevalent in the critical care setting and have high attributable morbidity and mortality. The purpose of this study was to identify factors that significantly contribute to immediate as well as eventual mortality in patients with bloodstream infections at a pediatric intensive care unit (PICU).

METHODS

Retrospective review of 2097 clinical records from admissions to our PICU in a 2-year period. Two separate case-control models were used. In the first model, eventual mortality (EM CASES) reflected those patients with eventual mortality, and EM CONTROLS were those who survived. In the second, infection-related mortality (IRM) cases were those with infection-related mortality, defined as death within 7 days of BSI, and IRM CONTROLS were survivors past 7 days. Logistic regression was used to adjust for differences for 3 categories: patient characteristics, microbiology and treatment variables.

RESULTS

We identified 74 separate episodes of bacteremia. Having an underlying malignancy or immunodeficiency was the only independently significant predictor of eventual mortality for BSI isolated within the PICU. Patients with infection-related mortality more likely had Gram-negative bacteremia and/or fungemia, were older and had inadequate initial empiric antibiotic treatment at the time BSI was diagnosed.

CONCLUSIONS

Targeted and aggressive early interventions should guide the empiric treatment of BSIs, whereas prolonged broad spectrum treatment should be minimized to avoid the emergence of resistant pathogen organisms.

Vancomycin usage in central venous catheters in a neonatal intensive care unit

BACKGROUND

We previously reported that vancomycin in hyperalimentation solution reduces catheter-related infections in the neonatal intensive care unit. Since June 1993 vancomycin (25 microg/ml) was routinely added to central venous catheter solutions, primarily hyperalimentation solution. Because the prophylactic use of vancomycin could lead to the emergence of resistant organisms, the decision to discontinue this practice was made in April of 1999. The use of vancomycin was reserved for documented infections with vancomycin-susceptible organisms.

OBJECTIVE

To compare catheter longevity, rate of laboratory-confirmed blood stream infections and total vancomycin exposure between two 18-month periods before and after the cessation of prophylactic vancomycin use.

METHODS

Data were evaluated for every neonate in whom a percutaneous central venous catheter was placed.

RESULTS

There were 394 neonates enrolled. No statistically significant difference was identified between the two periods regarding the mean catheter days or number of catheters per patient. There was a higher rate of Gram-negative laboratory-confirmed blood stream infections during Period I in patients with percutaneous central venous catheters in place. There were more isolates of coagulase-negative staphylococci in Period II, resulting in more frequent vancomycin therapy institution and thus an overall increase in the amount of vancomycin used in that period

CONCLUSION

Discontinuing the use of prophylactic vancomycin resulted in exposure of fewer neonates to vancomycin but a higher total amount of vancomycin used. The impact of low dose widespread exposure to vancomycin vs. high dose limited exposure on the microbiologic flora in the neonatal intensive care unit should be further examined.

Vancomycin and gentamicin in neonates: hindsight, current controversies, and forethought

The use of both vancomycin and gentamicin in the treatment of suspected or documented neonatal infections, while routine, is a challenge for bedside and advanced practice nurses caring for neonates in intensive care units. A review of the background information surrounding neonatal infections as well as the history, intended use, and the pharmacokinetic and pharmacodynamic properties of vancomycin and gentamicin is presented with the goal of aiding in proper treatment with these two medications. Specific attention is given to doses in special situations, means of drug monitoring, strategies for avoiding antibiotic resistance, alternative medication choices, and areas for future investigation.