Choice of antibiotics in late neonatal sepsis in the extremely low birth weight infant

Clinical and Laboratory Findings of Nosocomial Sepsis in Extremely Low Birth Weight Infants According to Causative Organisms

BACKGROUND

nosocomial sepsis remains a significant source of morbidity and mortality in extremely low birth weight (ELBW) infants. Early and accurate diagnosis is very important, but it is difficult due to the similarities in clinical manifestation between the causative microorganisms. We tried to identify the differences between causative microorganisms in clinical and laboratory findings and to help choose antibiotics, when sepsis was suspected in ELBW infants.

METHODS

a retrospective study was conducted on preterm infants, born at less than 28 weeks of gestation, with a birth weight of less than 1000 g between January 2009 and December 2019. Clinical and laboratory findings of suspected sepsis, after the first 72 h of life, were assessed. We classified them into four groups according to blood culture results (gram positive, gram negative, fungal, and negative culture groups) and compared them.

RESULTS

a total of 158 patients were included after using the exclusion criteria, with 45 (29%) in the gram positive group, 35 (22%) in the gram negative group, 27 (17%) in the fungal group, and 51 (32%) in the negative culture group. There were no significant differences in mean gestational age, birth weight, and neonatal morbidities, except for the age of onset, which was earlier in the fungal group than other groups. White blood cell (WBC) counts were the highest in the gram negative group and the lowest in the fungal group. The mean platelet counts were the lowest in the fungal group. C-reactive protein (CRP) levels were the highest in the gram negative group, while glucose was the highest in the fungal group.

CONCLUSIONS

in conclusion, we showed that there are some differences in laboratory findings, according to causative microorganisms in the nosocomial sepsis of ELBW infants. Increased WBC and CRP were associated with gram negative infection, while decreased platelet and glucose level were associated with fungal infection. These data may be helpful for choosing empirical antibiotics when sepsis is suspected.

Antibiotic exposure in neonates and early adverse outcomes: a systematic review and meta-analysis

Objectives

To systematically review and meta-analyse the relationship between antibiotic exposure in neonates and the following early adverse outcomes: necrotizing enterocolitis (NEC), invasive fungal infections (IFIs) and/or death.

Methods

Data sources were PubMed, Embase, Medline and the Cochrane Database (to December 2016), supplemented by manual searches of reference lists. Randomized controlled trials (RCTs) and observational studies were included if they provided data on different categories of antibiotic exposures (yes versus no, long versus short duration, and/or broad- versus narrow-spectrum regimens) and the risk of developing NEC, IFI and/or death in the neonatal period. Two reviewers extracted data and evaluated the risk of bias using the Cochrane Handbook, adapted to include observational studies. When appropriate, meta-analyses were conducted using the random-effect model.

Results

We identified 9 RCTs and 38 observational studies. The quality of the majority of studies was poor to moderate. There was a significant association between prolonged antibiotic exposure and an increased risk of NEC in five observational studies (5003 participants) and/or risk of death in five observational studies (13 534 participants). Eleven of 15 studies with data on broad- versus narrow-spectrum regimens reported an increased risk of IFI after broad-spectrum antibiotic exposure, in particular with third-generation cephalosporins and carbapenems. Meta-analysis was limited by few and old RCTs, insufficient sample sizes and diversity of antibiotic exposure and outcomes reported.

Conclusions

Prolonged antibiotic exposure in uninfected preterm infants is associated with an increased risk of NEC and/or death, and broad-spectrum antibiotic exposure is associated with an increased risk of IFI.

Coagulase-negative staphylococcal infections in a neonatal intensive care unit: In vivo response to cloxacillin

BACKGROUND

Following the introduction of cloxacillin and gentamicin as the first line of treatment for possible late-onset sepsis (LOS) in the authors' neonatal intensive care unit (NICU), it was subsequently noted that very low birth weight (VLBW) infants improved clinically, despite subsequently positive blood cultures for oxacillin-resistant, coagulase-negative Staphylococcus (CONS). The results of the management of VLBW infants with CONS sepsis during one calendar year, based on clinical rather than laboratory findings, are presented.

METHODS

VLBW infants with LOS were identified through the neonatal database, and the charts of those with CONS were reviewed for antibiotic usage, antibiotic resistance pattern, clearance of CONS from the blood and NICU discharge status. Oxacillin sensitivity was determined by the presence of the mecA gene.

RESULTS

From January 1 to December 31, 2002, 27 VLBW infants, treated in the authors' NICU for LOS due to CONS, were identified. The mean age of LOS infants with CONS was 15 days (median 12 days; range three to 54 days), the mean birth weight (+/- SD) was 904+/-247 g, and the mean gestational age at birth (+/- SD) was 27+/-2 weeks. All infants were started on cloxacillin and gentamicin, and improved clinically over the first 48 h. Six isolates were sensitive to cloxacillin. Twenty-three infants grew oxacillin-resistant CONS, eight of whom had persistence of CONS on repeat culture secondary to central lines. Two infants grew two strains of CONS. Eighteen of 22 infants (82%) with in vitro oxacillin-resistant CONS had clearance of bacteremia with cloxacillin and gentamicin. Ten infants (37%) received vancomycin, based on the authors' guidelines. There were no cases of prolonged bacteremia requiring rifampicin. Three infants died, but none of the deaths could be attributed to CONS.

DISCUSSION

The authors describe clinical improvement with clearance of CONS using cloxacillin and gentamicin, despite laboratory results suggesting oxacillin resistance. The authors' unit policy was based on clinical response and permitted the continuation of cloxacillin, provided that a repeat blood culture was negative. Vancomycin use was suggested for clinical deterioration or persistence of CONS. These results question the in vitro tests of resistance. Clearance of oxacillin-resistant CONS from the blood points to in vivo sensitivity, while the laboratory testing suggests in vitro resistance. The absence of subsequent positive blood cultures for CONS confirms clearance of this organism.

CONCLUSION

It was demonstrated that cloxacillin (150 mg/kg/day dose), along with gentamicin, can clear CONS from the blood within 48 h. The relationship between in vivo and in vitro sensitivities also needs to be further studied both in the laboratory and in a prospective trial.

Cloxacillin versus vancomycin for presumed late-onset sepsis in the Neonatal Intensive Care Unit and the impact upon outcome of coagulase negative staphylococcal bacteremia: a retrospective cohort study

Background

Coagulase negative staphylococcus (CONS) is the main cause of late-onset sepsis in Neonatal Intensive Care Units (NICU). Although CONS rarely causes fulminant sepsis, vancomycin is frequently used as empiric therapy. Indiscriminate use of vancomycin has been linked to the emergence of vancomycin resistant organisms. The objective of this study was to compare duration of CONS sepsis and mortality before and after implementation of a policy of selective vancomycin use and compare use of vancomycin between the 2 time periods.

Methods

A retrospective study was conducted of infants ≥4 days old, experiencing signs of sepsis with a first positive blood culture for CONS, during two 12-month periods. Late-onset sepsis was treated empirically with vancomycin and gentamicin during period 1, and cloxacillin and gentamicin during period 2. The confidence interval method was used to assess non-inferiority of the outcomes between the two study groups.

Results

There were 45 episodes of CONS sepsis during period 1 and 37 during period 2. Duration of sepsis was similar between periods (hazard ratio of 1.00, 95%CI: 0.64, 1.57). One death during period 2 was possibly related to CONS sepsis versus none in period 1. Vancomycin was used in 97.8% of episodes in period 1 versus 81.1% of episodes in period 2.

Conclusion

Although we failed to show non-inferiority of duration of sepsis in the cloxacillin and gentamicin group compared to the vancomycin and gentamicin group, duration of sepsis was clinically similar. Restricting vancomycin for confirmed cases of CONS sepsis resistant to oxacillin appears effective and safe, and significantly reduces vancomycin use in the NICU.