Multimodal Monitoring of Hemodynamics in Extremely Low Birth Weight Preterm Infant in a Canadian Tertiary Level Unit

Low blood pressure is a common problem in the premature newborn and can affect over 30% of all Extremely Low Gestational Age Neonates (ELGAN) babies delivered less than 28 weeks completed. Neonatal clinicians assess the hemodynamic status of the infant using clinical signs and physiological parameters including heart rate, blood pressure, capillary refill time, urine output and laboratory parameters (base deficit and lactate). While urine output and laboratory parameters do not provide real-time assessment of the hemodynamic status, heart rate and capillary refill time could be non-specific, inaccurate and observer-dependent, respectively. Blood pressure (BP) continues to be used as a common physiological marker for cardiovascular state in neonates.However, there is increasing amount of evidence that monitoring blood pressure alone is not enough to ensure adequate systemic and cerebral perfusion and oxygenation. Indeed, preterm babies may have "low blood pressure" triggering pharmacological treatment while still maintaining adequate systemic flow- especially cerebral and other organ perfusion as shown by other noninvasive measures like targeted neonatal echocardiography (TNE) and near infrared spectroscopy (NIRS). Using mean BP alone as the indication of treatment of neonatal cardiovascular compromise without taking into consideration the status of tissue perfusion may lead to unnecessary exposure of neonates to vasoactive medication. This medication can be potentially harmful to these extremely vulnerable patients. Analysis of a large neonatal database has demonstrated that treatment of hypotension was associated with an increase in serious brain injury. This held true even after the blood pressure was included in the regression mode, suggesting that it is treatment of hypotension, rather than the presence of hypotension which is harmful. The common interventions, fluid boluses followed by inotropes, could as well be harmful. Observational data has shown an associ