Keywords
neonate - fever - phototherapy - hyperbilirubinemia - serious bacterial infection
- hyperthermia evaluation
Approximately 2% of full-term neonates are evaluated for fever in the neonatal period,
with variable approaches in the evaluation and care of these patients.[1]
[2] Of these patients, the prevalence of life-threatening serious bacterial infections
(SBIs) has remained approximately 10% for more than 30 years.[1] Though the 2021 American Academy of Pediatrics Clinical Practice Guideline for the
evaluation and treatment of well-appearing febrile neonates provides a means of decreasing
practice variability, confounding factors that cause hyperthermia can lead to inconsistencies
in management.
One potential confounding factor is phototherapy for neonatal hyperbilirubinemia.
Given the nuances of isolette temperature regulation and perception of the phototherapy/isolette
environment leading to higher temperatures, some providers question whether hyperthermia
during phototherapy is due to environmental factors or underlying infection. This
adds variability in the evaluation and management of patients who have a fever while
undergoing phototherapy. Our study aimed to assess the prevalence of hyperthermia
in neonates undergoing phototherapy for hyperbilirubinemia and the significance of
hyperthermia as it relates to SBI in this population.
Methods
Through retrospective chart review at a single, quaternary care pediatric institution,
we extracted temperature measurements from the electronic medical records (EMRs) of
neonates admitted to acute care units for hyperbilirubinemia requiring phototherapy
over a 4-year period from 2019 to 2022. Detailed chart review of neonates with temperature
≥38°C revealed when further evaluation was conducted and the outcomes of any such
evaluation. From these data, we calculated the prevalence of hyperthermia in neonates
who were undergoing phototherapy and the prevalence of SBI in this population. Patients
of interest for the study were identified using relevant International Classification
of Diseases (ICD) codes for hyperbilirubinemia requiring phototherapy. Chart review
included data gathered for that admission as well as a review for possible readmissions
over the subsequent 2 weeks to capture any patients that may have had SBI during this
time. The study was approved by our Institutional Review Board.
Results
During the study period, 639 infants were admitted to an acute care bed with the diagnosis
of hyperbilirubinemia requiring phototherapy. Nine (1.4%) of these infants had recorded
temperatures ≥38°C. Of these, two (22%) had an SBI. For the other seven febrile patients,
one underwent evaluation for a potential SBI, which was negative. None returned for
care within 2 weeks following discharge. Details of these patients are seen in [Table 1] and [Fig. 1].
Table 1
Patients noted to have temperature ≥38°C while admitted for phototherapy for hyperbilirubinemia,
associated documentation, evaluation course, and clinical outcome
|
Patient
|
Age at presentation (d)
|
Maximum temperature reading
|
Hyperthermia noted in provider documentation?
|
SBI evaluation performed?
|
Patient outcome
|
Provider rationale in documentation (when hyperthermia is noted)
|
|
A
|
4
|
38.0
|
Yes
|
No
|
Returned to care 2 d after index discharge with E. coli sepsis/meningitis
|
She had an elevated temperature while admitted under phototherapy, tmax of 100.4,
which resolved after bili lights were discontinued. Subsequent temps were all within
normal limits. No sepsis workup was initiated at this time, as this was thought to
be environmental, and no antibiotics were given. ANC on admission was <4,000 with
no notable WBC elevation
|
|
B
|
5
|
38.0
|
Yes
|
Yes
|
E. coli bacteremia, treated effectively without adverse outcome
|
|
|
C
|
3
|
38.2
|
No
|
No
|
No further fever and no return for care after discharge
|
|
|
D
|
3
|
38.0
|
Yes
|
No
|
No further fever and no return for care after discharge
|
One temperature up to 38.0, but occurred when in an isolette, under phototherapy.
Upon repeat, her temperature decreased to 37.3 within 30 min without intervention,
so a rule-out sepsis evaluation was not performed
|
|
E
|
3
|
38.0
|
No
|
No
|
No further fever and no return for care after discharge
|
|
|
F
|
4
|
38.0
|
Yes
|
Yes
|
Blood, urine, and CSF cultures were all negative. No return for care after discharge
|
|
|
G
|
5
|
38.1
|
No
|
No
|
No further fever and no return for care after discharge
|
|
|
H
|
5
|
38.3
|
No
|
No
|
No further fever and no return for care after discharge
|
|
|
I
|
7
|
38.1
|
No
|
No
|
No further fever and no return for care after discharge
|
|
Fig. 1 Evaluation of patients with hyperthermia during admission for phototherapy.
Discussion
In our cohort, the prevalence of hyperthermia in patients undergoing phototherapy
was 1.4% and relatively low. Compared with the previously reported 2% suggesting no
increased risk for hyperthermia when undergoing phototherapy. Most noteworthy, in
our study, the prevalence of SBI in febrile neonates (22%) receiving phototherapy
exceeded that of the general febrile neonate population published previously.[1]
Given similar or even lower rates of fever in neonates undergoing phototherapy, and
higher prevalence of SBI we observed in our data, we believe that the environmental
impacts of phototherapy should not be used as an explanation for hyperthermia in this
patient population and that these patients should undergo further SBI evaluation.
Limitations of our study include only a single center and a relatively small sample
size. Our patient data was pulled using ICD codes for hyperbilirubinemia requiring
phototherapy, but may be impacted by variabilities in primary diagnosis codes, possibly
leading to patients not being included in our data. Additionally, it is possible that
patients treated within our system for hyperbilirubinemia may have been admitted with
an SBI to another facility and, therefore, not accessible in our EMR.
Many guidelines for the evaluation and management of hyperthermia in neonates include
hyperbilirubinemia as a risk factor for underlying sepsis. Therefore, the presence
of hyperthermia and hyperbilirubinemia deserves further evaluation for an underlying
infectious etiology.
