Blood Pressure Goals: Is Cerebral Saturation the New Mean Arterial Pressure?

Abstract

Objective: To correlate hypotension and cerebral saturation from near-infrared spectroscopy (cNIRS) in neonates on dopamine. Study Design: Retrospective review of neonates receiving dopamine between August 2018-2019 was performed. Hypotension thresholds included mean arterial pressure (MAP) of postmenstrual age (PMA) ± 5mmHg, 30mmHg, and gestational age (GA) ± 5mmHg. Time below threshold MAP was compared to time with cerebral hypoxia (cNIRS <55%). Results: Hypotension occurred 6-33% of time on dopamine in 59 cases. Hypotension did not correlate with abnormal cNIRS overall, within PMA subgroups, or by outcomes. Hypotensive periods with MAP<GA had fewer corresponding percent time with abnormal cNIRS events (3.7±1.3%) compared to MAP <PMA (11.9±4.9%, p<0.003) or 30 mm Hg thresholds (12.2±4.7%, p<0.0001). In the most premature infants, mean cNIRS values during hypotension were still within normal range (57±6%). Conclusion: cNIRS may be a more clinically relevant measure than MAP for assessment of neonatal hypotension.

An Update on Pharmacologic Management of Neonatal Hypotension: When, Why, and Which Medication

“…The important differences and limitations of the published study design, along with the complex pathophysiology of AH in preterm infants, add to the difficulties in defining and treating AH in this fragile population [7,20,26]. In fact, a prospective observational study showed that 3-49% of ELBWI with low AP did not receive anti-hypotensive treatment; however, 28-41% of infants without low AP were treated.…”

“…Moreover, the use of targeted neonatal echocardiography and Near-InfraRed Spectroscopy (NIRS) monitoring for assessing heart function and cerebral perfusion, respectively, can add to the identification of AH needing inotrope/vasopressor treatment. The importance of NIRS as a complementary tool for the evaluation of the hypotensive neonate is supported by studies showing that cerebral oxygen delivery may not correlate with the presence of hypotension [20,25]. This finding suggests that the low AP measurement cannot accurately indicate potentially decreased cerebral oxygenation, which is a central target of anti-hypotensive treatment [20,[25][26][27].…”

“…The importance of NIRS as a complementary tool for the evaluation of the hypotensive neonate is supported by studies showing that cerebral oxygen delivery may not correlate with the presence of hypotension [20,25]. This finding suggests that the low AP measurement cannot accurately indicate potentially decreased cerebral oxygenation, which is a central target of anti-hypotensive treatment [20,[25][26][27].…”

“…In summary, available data regarding the role of AVP and its homolog terlipressin as a rescue therapy in neonates with volume and catecholamine-refractory shock support their efficacy in restoring AP and improving tissue perfusion and oxygenation. However, the sparse data on optimal dosing and safety in neonates, as well unknown effects on long-term ND outcomes, do not allow for definite conclusions to be drawn [20].…”

“…Another important issue is the conflicting results surrounding the effects of AH and its treatment with vasoactive medications on short-term outcomes. Data on long-term outcomes of preterm infants are insufficient to support definite conclusions [7,[12][13][14][15][16][17][18][19][20].…”