Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2023 Jul 28;49(9):1062–1078. doi: 10.1007/s00134-023-07165-x

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© The Author(s) 2023

Open Access This article is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, which permits any non-commercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc/4.0/.

PMC Copyright notice

Fig. 2 — Regulation of cerebral blood flow and convective oxygen delivery. Panel A depicts the relationship between cerebral blood flow (CBF) and mean arterial blood pressure (MAP), the partial pressure of arterial carbon dioxide (PaCO₂), and the partial pressure of oxygen (PaO₂). During changes in blood pressure, the brain is more effective at combating increases as opposed to decreases in MAP. CBF changes linearly and proportionally to changes in PaCO₂ until extreme levels of hypocapnia or hypercapnia. Decreases in PaO₂ lead to a curvilinear increase in CBF in conjunction with the curvilinear nature of the oxyhaemoglobin dissociation curve. Panel B depicts the influence of PaO₂ and haemoglobin concentration [Hb] on arterial oxygen content (CaO₂). Separate lines for [Hb] concentrations are depicted for a haemoglobin concentration of 15 g/dL as well as two Hb thresholds that have been studied as transfusion thresholds in other patient groups in the intensive care unit. The minimal increase in CaO₂ that results from supplemental oxygen leading to a PaO₂ of up to 300 mmHg is also depicted. Panel C depicts a graphical overview of how increases and decreases in each of the factors depicted in panels A and B influence the overall convective cerebral delivery of oxygen (CDO₂)