Safety and effectiveness of a non-electric infant warmer for hypothermia in Rwanda: A cluster-randomized stepped-wedge trial

Abstract

Background: Neonatal hypothermia is a common source of morbidity and mortality in low resource settings. We developed the Dream Warmer, a low cost, re-usable non-electric infant warmer to prevent and treat hypothermia.

Methods: We conducted a cluster-randomized stepped-wedge trial. The primary aim was to assess the effect on overall euthermia rates of introducing the warmer compared to standard of care in rural Rwandan hospitals. The secondary aims were to assess effects of warmer introduction on mortality, as well as the safety and feasibility of the warmer. Ten district hospitals participated in the study from November 19th 2019 to July 15th 2020. Patients were eligible to use the warmer if they were 1) hypothermic (temp < 36·5 °C) or 2) or at risk of hypothermia (weight < 2·5 kg or estimated post menstrual age < 35 weeks) when Kangaroo Mother Care was not available. An encounter was defined as the data from an individual infant on a single day. Trial of a Non Electric Infant Warmer for Prevention and Treatment of Hypothermia in Rwanda [NCT03890211].

Findings: Over the study period, 3179 patients were enrolled across the ten neonatal wards, yielding 12,748 encounters; 464 unique infants used the warmer 892 times, 79% eligible due to hypothermia. Because of limited study nurse resources, the warmer was used in only 18% of eligible encounters. Despite this low rate of warmer use, the rate of euthermia rose from 51% (95% CI 50-52%) of encounters pre-intervention to 67% (66-68%) post-intervention; p < 0·0001. Among the encounters in which the warmer was used, only 11% (9-13%) remained hypothermic. While mortality rates pre- and post-intervention did not change, mortality rate among those who used the warmer was significantly lower than among those who did not (0·9% vs 2·8%, p = 0·01). Use of the warmer did not affect hyperthermia rates. There were no safety concerns or instances of incorrect warmer use.

Interpretation: Introduction of the warmer increased rates of euthermia with no associated safety concerns.

Conflict of interest statement

Anne Hansen is the Founder and CEO, and Ashok Gadgil is member of the Board, of Global Newborn Solutions, a nonprofit founded to manufacture and distribute the Dream Warmer. Neither has ever received any financial compensation for their role. Ashok Gadgil and Vi Rapp have a US patent application titled "Differential-melting point PCM as safety indicator for warming devices" that was filed on Aug 22, 2020, by Regents of Univ. of California with UC Berkeley reference case number B20-037-2US which is pending. Anne Hansen reports other from Banyan Gates Foundation, has a patent, Infant Warming Pad, licensed to Lawrence Berkeley National Laboratory and a Patent, Differential-Melting Point PCM as Safety Indicator for Warming Devices licensed to US Berkeley. No conflicts of interest exist for other authors.

© 2021 The Authors.

Figures

Fig. 1.

CONSORT trial profile.

Fig. 2

Progression of new hospital enrollment every two weeks, transitioning from “pre phase” to “post phase” with four weeks of data collection at all hospital sites at the end of the study.

Fig. 3

Heat source with KMC: Pictorial representation of the dream warmer being used in conjunction with KMC and a hat.

Fig. 4

Stand-alone heat source: Pictorial representation of the dream warmer, inserted into an insulating sleeve with a window that allows visualization of the phase change material. Wearing a hat, the infant is laid directly on the warmer and then covered with a blanket.

Fig. 5

Temperature of infant warmer's edge vs time from start of use. Percentage of warmers maintaining temperature above specified thresholds, decreasing with time from start of encounter. At 6 h, 72% of warmers remained above 35 °C (upper curve). Bands indicate 95% confidence interval on time axis.