TY - JOUR
T1 - Red cell physiology and signaling relevant to the critical care setting
AU - Said, Ahmed
AU - Rogers, Stephen
AU - Doctor, Allan
N1 - Funding Information:
This work was supported by NIH 1R01GM113838-01 & UL1 RR024992WUSM, American Heart Association GIA 0950133G and Children’s Discovery Institute CH-LI-2013-420. A.D. has received research funding and/or consulting fees from: Viasys Inc., Entegrion Inc., Terumo BCT, Galleon Pharmaceuticals, Nitrox LLD, Nitric BioTherapeutics, Galera Inc., and Novartis. A.S. and S.R. have no conflicts to declare.
Publisher Copyright:
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - Purpose of review Oxygen (O2) delivery, the maintenance of which is fundamental to supporting those with critical illness, is a function of blood O2 content and flow. Here, we review red blood cell (RBC) physiology relevant to disordered O2 delivery in the critically ill. Recent findings Flow (rather than content) is the focus of O2 delivery regulation. O2 content is relatively fixed, whereas flow fluctuates by several orders of magnitude. Thus, blood flow volume and distribution vary to maintain coupling between O2 delivery and demand. The trapping, processing and delivery of nitric oxide (NO) by RBCs has emerged as a conserved mechanism through which regional blood flow is linked to biochemical cues of perfusion sufficiency. We will review conventional RBC physiology that influences O2 delivery (O2 affinity & rheology) and introduce a new paradigm for O2 delivery homeostasis based on coordinated gas transport and vascular signaling by RBCs. Summary By coordinating vascular signaling in a fashion that links O2 and NO flux, RBCs couple vessel caliber (and thus blood flow) to O2 need in tissue. Malfunction of this signaling system is implicated in a wide array of pathophysiologies and may be explanatory for the dysoxia frequently encountered in the critical care setting.
AB - Purpose of review Oxygen (O2) delivery, the maintenance of which is fundamental to supporting those with critical illness, is a function of blood O2 content and flow. Here, we review red blood cell (RBC) physiology relevant to disordered O2 delivery in the critically ill. Recent findings Flow (rather than content) is the focus of O2 delivery regulation. O2 content is relatively fixed, whereas flow fluctuates by several orders of magnitude. Thus, blood flow volume and distribution vary to maintain coupling between O2 delivery and demand. The trapping, processing and delivery of nitric oxide (NO) by RBCs has emerged as a conserved mechanism through which regional blood flow is linked to biochemical cues of perfusion sufficiency. We will review conventional RBC physiology that influences O2 delivery (O2 affinity & rheology) and introduce a new paradigm for O2 delivery homeostasis based on coordinated gas transport and vascular signaling by RBCs. Summary By coordinating vascular signaling in a fashion that links O2 and NO flux, RBCs couple vessel caliber (and thus blood flow) to O2 need in tissue. Malfunction of this signaling system is implicated in a wide array of pathophysiologies and may be explanatory for the dysoxia frequently encountered in the critical care setting.
KW - O delivery
KW - erythrocyte
KW - nitric oxide
KW - red blood cell
UR - http://www.scopus.com/inward/record.url?scp=84960113057&partnerID=8YFLogxK
U2 - 10.1097/MOP.0000000000000225
DO - 10.1097/MOP.0000000000000225
M3 - Review article
C2 - 25888155
AN - SCOPUS:84960113057
VL - 27
SP - 267
EP - 276
JO - Current Opinion in Pediatrics
JF - Current Opinion in Pediatrics
SN - 1040-8703
IS - 3
ER -