**Author details**

Microcirculation in the newborn can be assessed using a variety of methods, the most commonly used is the evaluation of flow by laser‐Doppler method, video microscopy (dynamic capillaroscopy), and xenon clearance techniques [59]. Flow measurement by laser‐Doppler method is based on the fact that the frequency of the light beam, which passes through the tissue, changes as a result of reflection from the moving parts—red blood cells (the Doppler effect). The flow is proportional to the concentration and speed of moving red blood cells in the microcirculation. Since the flow in microcirculation is highly variable, we usually assess microcirculatory response to some of the challenge tests and monitor the dynamics of change. The most commonly used provocation meth‐ ods are the postocclusive reactive hyperemia (hyperemia after a transitional cuffing of the proximal artery), thermal methods (local heating or cooling), and iontophoresis of vasoactive substances [60, 61]. In the first days after birth, the blood flow is very fragile and the peripheral blood flow in the microcirculation is unstable. The myogenic and nervous controls of skin blood flow enable thermoregulation. The blood flow to the skin in the first days after birth is reduced. The blood flow is related to gestational and post‐ natal age and the incidence of morbidity and cardiovascular function [62]. The deterio‐ ration of peripheral blood flow regulation in microcirculation causes vasodilation and decreased peripheral vascular resistance and contributes to the vulnerability of blood flow. The peripheral blood flow in the first days after birth differs in boys and girls; boys have stronger vasodilation; the mechanism is possibly associated with an increased

The described methods for hemodynamic monitoring of neonates have many limitations. The clinical ones are vastly subjective and do not correlate well with the laboratory methods. The continuous bedside noninvasive methods are less accurate and sometimes demand complex deducement to what is happening. There are no trials on resuscitation using the noninva‐ sive methods. The more sophisticated noninvasive methods require expensive equipment and are time consuming, measuring the parameters in the moment of measurement and not

Hemodynamic monitoring, which was for a long time not available in neonates and prema‐ tures, is becoming an indispensable tool for understanding how cardiovascular system adapts to extrauterine life. This is especially important when treating the smallest premature with peculiar and very vulnerable hemodynamics. This article adds some of the latest information on hemodynamic monitoring in neonates with specific emphasis on the methods which are

available, cost‐effective, noninvasive, and easy to manage and understand.

incidence of hypotension in newborn males [63].

**6. Limitations**

38 Selected Topics in Neonatal Care

continuously.

**7. Conclusion**

Petja Fister<sup>1</sup> \* and Štefan Grosek2,3

\*Address all correspondence to: petja\_fister@yahoo.com

1 Department of Neonatology, University Children's Hospital, University Medical Center Ljubljana, Ljubljana, Slovenia

2 Department of Pediatric Surgery and Intensive Therapy, Surgical Service, University Medical Center Ljubljana, Ljubljana, Slovenia

3 Department of Pediatrics, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
