Neonatal Septicemia

Blood Cell Deformation in Neonates Who Have Sepsis

Otwin Linderkamp, Johannes Pöschl, Peter Ruef
Division of Neonatology, Department of Pediatrics, University of Heidelberg, Heidelberg, Germany

Objectives. After completing this article, readers should be able to:
1- Describe alterations of red blood cells due to bacterial toxins.
2- Describe physical alterations of neutrophils during activation.
3- Delineate the role of red and white blood cells in the impairment of microcirculation and organ damage in sepsis.
4- List drugs that may inhibit neutrophil activation and improve their deformability and their actions.

Introduction. Sepsis remains a major cause of morbidity and mortality in neonates, particularly among preterm infants. (1) Impaired microcirculatory blood flow plays a pivotal role in the development of clinical manifestations and organ dysfunctions in severe sepsis and septic shock. (2)(3)(4) If not corrected, microcirculatory dysfunction can progress to organ dysfunction and subsequently to organ failure and death. Restoration of microcirculatory dysfunction is, therefore, an important step in preventing long-term sequelae (including brain damage) and death of the patient.
Both red and white blood cells must deform to pass through narrow channels whose diameters are less than those of the cells. (5) Impaired deformability of red and white blood cells may contribute to impaired microcirculatory blood flow in septicemia.

Impaired Deformability of Red Blood Cells in Neonatal Septicemia.
The membranes of neonatal red blood cells (RBCs) deform more in response to a given force than adult cells and are, therefore, more flexible. (6)(7) On the other hand, neonatal RBCs are larger and require higher pressures to enter filter pores and micropipettes that have diameters below the resting cellular diameters. (8)(9) The larger volume and increased deformability of neonatal RBCs are responsible for another favorable property, the increased Fahraeus and Fahraeus-Lindqvist effect (ie, hematocrit and viscosity reduction when going from 500- to 50-mcm tubes). (10) These favorable flow properties of neonatal RBCs suggest that their increased cellular deformability is a prerequisite for . . . [Full Text of this Article]

NeoReviews Vol.7 No.10 2006 e517
© 2006 American Academy of Pediatrics