A total of 1667 neonates born at ≥ 34 weeks’ GA during the study period at our institution were identified using admission logs. Patients at low risk for EOS (1394/1667, 83.6%) and those who met exclusion criteria (8/1667, 0.5%) were excluded from the study. Thus, a total of 265 (15.9%) patients fulfilled inclusion criteria and were enrolled in the study.
According to our guidelines, 32/265 (12.1%) neonates were initiated on antibiotics in the first 12 hours of life; none was initiated on antibiotics at 13–72 hours of life.
A retrospective analysis of blood culture, CRP and PCT results was performed to calculate the incidence rate of EOS during the study period. No cases of culture-positive EOS were observed among the study population; 4 cases of culture-negative EOS were reported among inborn infants ≥ 34 weeks’ GA. All 4 patients with culture-negative EOS had no risk factors for EOS and were medium-risk patients with one or two clinical signs of EOS within the first 12 hours of life. They all presented simultaneous increase of both CRP and PCT at the onset of symptoms or increase of PCT at the onset of symptoms followed by an increase of CRP. Thus, the incidence of EOS among inborn infants ≥ 34 weeks’ GA during the study period was 2.4/1000 live births.
After entering the data into the EOS calculator with local EOS incidence of 2/1000 live births, the recommendations were as follows: 1) No culture, no antibiotics, routine vitals (168 patients); 2) No culture, no antibiotics, vitals every 4 hours for 24 hours (7 patients); 3) Blood culture, vitals every 4 hours for 24 hours (35 patients); 4) Strongly consider starting empiric antibiotics, vitals per NICU (1 patient); 5) Empiric antibiotics, vitals per NICU (54 patients). Thus, according to EOS calculator, antibiotics were needed in 55/265 (20.7%) patients in the first 12 hours of life. The difference with our local guidelines resulted statistically significant (p < 0.0001). Data are shown in Fig. 2.
FIGURE 2
Title: Comparison between our local guidelines and EOS calculator. Neonates ≥ 34 weeks’ GA.
Legends: EOS, early-onset sepsis; GA, gestational age; GBS, Group B Streptococcus; IAP, intrapartum antibiotic prophylaxis; R1, recommendation No. 1 (No culture, no antibiotics, routine vitals); R2, recommendation No. 2 (No culture, no antibiotics, vitals every 4 hours for 24 hours); R3, recommendation No. 3 (Blood culture, vitals every 4 hours for 24 hours); R4, recommendation No. 4 (Strongly consider starting empiric antibiotics, vitals per NICU); R5, recommendation No. 5 (Empiric antibiotics, vitals per NICU).
As no cases of culture-positive EOS were observed during the study period, we also entered the same data into the EOS calculator with the lowest possible local EOS incidence (0.1/1000 live births). The recommendations were as follows: 1) No culture, no antibiotics, routine vitals (218 patients); 2) No culture, no antibiotics, vitals every 4 hours for 24 hours (1 patient); 3) Blood culture, vitals every 4 hours for 24 hours (2 patients); 4) Strongly consider starting empiric antibiotics, vitals per NICU (40 patients); 5) Empiric antibiotics, vitals per NICU (4 patients). Thus, according to EOS calculator, antibiotics were needed in 44/265 (16.6%) patients in the first 12 hours of life; the difference with our local guidelines resulted statistically significant even in this case (p < 0.025).
A full-term newborn with culture-negative EOS starting with respiratory distress 6 hours after birth received antibiotics according to our local guidelines; when using EOS calculator, this patient was classified as “equivocal” and would not have received antibiotics with EOS incidence 0.1/1000 live births.
As regards treatment, overlap between EOS calculator recommendations and our local guidelines was 88.3% (234/265 patients) when using EOS calculator with EOS incidence 2/1000 live births, and 90.9% (241/265 patients) when using EOS calculator with EOS incidence 0.1/1000 live births. Data are shown in Fig. 2.
The patients enrolled in the study were hence assessed by dividing them into 2 groups: 1) 34–36 weeks’ GA neonates; 2) ≥ 37 weeks’ GA neonates.
Inborn infants 34–36 weeks’ GA were 95/265 (35.8%). According to our local guidelines, 26/95 (27.4%) of these neonates were initiated on antibiotics in the first 12 hours of life. Neither culture-positive nor culture-negative EOS were observed among infants 34–36 weeks’ GA during the study period. After entering data into the EOS calculator with the lowest possible local EOS incidence (0.1/1000 live births), the recommendations for patients 34–36 weeks’ GA were as follows: 1) No culture, no antibiotics, routine vitals (62 patients); 2) No culture, no antibiotics, vitals every 4 hours for 24 hours (0 patients); 3) Blood culture, vitals every 4 hours for 24 hours (0 patients); 4) Strongly consider starting empiric antibiotics, vitals per NICU (29 patients); 5) Empiric antibiotics, vitals per NICU (4 patients). Thus, according to EOS calculator, antibiotics were needed in 33/95 (34.7%) patients 34–36 weeks’ GA in the first 12 hours of life; the difference with our local guidelines was not statistically significant (p = 0.146), although 7 more patients would have been treated using EOS calculator compared to our approach. Data are shown in Fig. 3.
FIGURE 3
Title: Comparison between our local guidelines and EOS calculator. Neonates 34–36 weeks’ GA.
Legends: EOS, early-onset sepsis; GA, gestational age; GBS, Group B Streptococcus; IAP, intrapartum antibiotic prophylaxis; R1, recommendation No. 1 (No culture, no antibiotics, routine vitals); R2, recommendation No. 2 (No culture, no antibiotics, vitals every 4 hours for 24 hours); R3, recommendation No. 3 (Blood culture, vitals every 4 hours for 24 hours); R4, recommendation No. 4 (Strongly consider starting empiric antibiotics, vitals per NICU); R5, recommendation No. 5 (Empiric antibiotics, vitals per NICU).
Inborn infants ≥ 37 weeks’ GA were 170/265 (64.2%). According to our local guidelines, 6/170 (3.5%) of these neonates were initiated on antibiotics in the first 12 hours of life. A retrospective analysis of blood culture, CRP and PCT results showed no cases of culture-positive EOS and 4 cases of culture-negative EOS among the 1532 inborn infants ≥ 37 weeks’ GA during the study period. Thus, the calculated incidence rate of EOS was 2.6/1000 live births. After entering data into the EOS calculator with local EOS incidence of 2/1000 live births, the recommendations were as follows: 1) No culture, no antibiotics, routine vitals (131 patients); 2) No culture, no antibiotics, vitals every 4 hours for 24 hours (4 patients); 3) Blood culture, vitals every 4 hours for 24 hours (17 patients); 4) Strongly consider starting empiric antibiotics, vitals per NICU (0 patients); 5) Empiric antibiotics, vitals per NICU (18 patients). Thus, according to EOS calculator, antibiotics were needed in 18/170 (10.6%) patients in the first 12 hours of life; the difference with our local guidelines resulted statistically significant (p = 0.001). Data are shown in Fig. 4.
FIGURE 4
Title: Comparison between our local guidelines and EOS calculator. Neonates ≥ 37 weeks’ GA.
Legends: EOS, early-onset sepsis; GA, gestational age; GBS, Group B Streptococcus; IAP, intrapartum antibiotic prophylaxis; R1, recommendation No. 1 (No culture, no antibiotics, routine vitals); R2, recommendation No. 2 (No culture, no antibiotics, vitals every 4 hours for 24 hours); R3, recommendation No. 3 (Blood culture, vitals every 4 hours for 24 hours); R4, recommendation No. 4 (Strongly consider starting empiric antibiotics, vitals per NICU); R5, recommendation No. 5 (Empiric antibiotics, vitals per NICU).
As no cases of culture-positive EOS were observed among inborn infants ≥ 37 weeks’ GA, we also entered the same data into the EOS calculator with the lowest possible local EOS incidence (0.1/1000 live births). The recommendations were as follows: 1) No culture, no antibiotics, routine vitals (156 patients); 2) No culture, no antibiotics, vitals every 4 hours for 24 hours (1 patient); 3) Blood culture, vitals every 4 hours for 24 hours (2 patients); 4) Strongly consider starting empiric antibiotics, vitals per NICU (11 patients); 5) Empiric antibiotics, vitals per NICU (0 patients). Thus, according to EOS calculator, antibiotics were needed in 11/170 (6.5%) patients in the first 12 hours of life; the difference with our local guidelines was not statistically significant (p = 0.131), although 5 more patients would have been treated using EOS calculator compared to our approach. Data are shown in Fig. 4.