Importance: Cycled (intermittent) phototherapy (PT) might adequately control peak total serum bilirubin (TSB) level and avoid mortality associated with usual care (continuous PT) among extremely low-birth-weight (ELBW) infants (401-1000 g).
Objective: To identify a cycled PT regimen that substantially reduces PT exposure, with an increase in mean peak TSB level lower than 1.5 mg/dL in ELBW infants.
Design, setting, and participants: This dose-finding randomized clinical trial of cycled PT vs continuous PT among 305 ELBW infants in 6 US newborn intensive care units was conducted from March 12, 2014, to November 14, 2018.
Interventions: Two cycled PT regimens (≥15 min/h and ≥30 min/h) were provided using a simple, commercially available timer to titrate PT minutes per hour against TSB level. The comparator arm was usual care (continuous PT).
Main outcomes and measures: Mean peak TSB level and total PT hours through day 14 in all 6 centers and predischarge brainstem auditory-evoked response wave V latency in 1 center. Mortality and major morbidities were secondary outcomes despite limited power.
Results: Consent was requested for 452 eligible infants and obtained for 305 (all enrolled) (mean [SD] birth weight, 749 [152] g; gestational age, 25.7 [1.9] weeks; 81 infants [27%] were multiple births; 137 infants [45%] were male; 112 [37%] were black infants; and 107 [35%] were Hispanic infants). Clinical and demographic characteristics of the groups were similar at baseline. After a preplanned interim analysis of 100 infants, the regimen of 30 min/h or more was discontinued, and the study proceeded with 2 arms. Comparing 128 infants receiving PT of 15 min/h or more with 128 infants receiving continuous PT among those surviving to 14 days, mean peak TSB levels were 7.1 vs 6.4 mg/dL (adjusted difference, 0.7; 95% CI, 0.4-1.1 mg/dL) and mean total PT hours were 34 vs 72 (adjusted difference, -39; 95% CI, -45 to -32). Wave V latency adjusted for postmenstrual age was similar in 37 infants receiving 15 min/h or more of PT and 33 infants receiving continuous PT: 7.42 vs 7.32 milliseconds (difference, 0.10; 95% CI, -0.11 to 0.30 millisecond). The relative risk for death was 0.79 (95% CI, 0.40-1.54), with a risk difference of -4.5% (95% CI, -10.9 to 2.0). Morbidities did not differ between groups.
Conclusions and relevance: Cycled PT can substantially reduce total PT with little increase in peak TSB level. A large, randomized trial is needed to assess whether cycled PT would increase survival and survival without impairment in small, preterm infants.
Trial registration: ClinicalTrials.gov Identifier: NCT01944696.