O2109: Rates of Peri-transport Abnormal Vital Signs and Laboratory Values for Infants with Hypoxic Ischemic Encephalopathy

Background: Many infants with hypoxic ischemic encephalopathy (HIE) will require transport to a higher level of care for evaluation and management. Infants with HIE are at high risk for decompensation during the medical transport process. Understanding the specific risks to cardiopulmonary and laboratory stability is an important step in ensuring patient safety during transport.

Methods: Neonates diagnosed with HIE who were transported to a tertiary NICU for treatment between March 2020-March 2021 had data collected from the transport team and electronic medical record. Demographics, detailed vital signs during transport, and admission laboratory values were descriptively analyzed. Rates of vital sign abnormalities were calculated based on published gestational age norms and goal therapeutic hypothermia temperatures (33-34 C).

Results: 39 transported infants with HIE were included (demographics are shown in Table 1). Vital signs were abnormal in a majority of infants with abnormal systolic blood pressure in 80% (n=31) abnormal heart rate in 36% (n=14), and abnormal oxygen saturation in 28% (n=11). Although the majority (n=27, 70%) were actively cooled on transport, temperature was outside of goal range (33-34C) on at least one measurement in all infants (Fig 1). However, 80% of babies were at goal temperature at the time of admission. Median peak lactate levels in the first 24 hours of life were 7.6 (IQR 8.6). Many infants had abnormal pre-transport blood gas values. Cord blood gases showed a median pH 7.05 (IQR 0.21), pCO2 59.5 (IQR 46.2), bicarbonate 19 (IQR 4.2), and base deficit -14.3 (IQR 8.8). Blood gases drawn in the first hour of life showed a median pH 7.03 (IQR 0.38), CO2 49.9 (IQR 45.8), bicarbonate 13.6 (IQR 9.6), and base deficit -15.5 (IQR 10.8). Admission blood gases showed a median pH 7.28 (IQR 0.18), CO2 40 (IQR 22), bicarbonate 19.7 (IQR 10.2), and base deficit -8.1 (IQR 13.7).

Conclusion: Transported infants with HIE have high rates of abnormal vital signs and all studied infants were outside of goal therapeutic hypothermia temperature range at points during their transport. Physiologic changes associated with hypothermia as well as short transport distances likely contributed to these abnormalities. Acid base and respiratory laboratory values are often abnormal, especially prior to transport. Neonatal transport teams should have specific training, equipment, monitoring and medications to address these issues en route in order to provide optimal patient care.