Density of Lumbar Cerebrospinal Fluid in Pregnant and Nonpregnant Humans

Abstract

Comment: The authors of this research have given us some important, accurate, and interesting data concerning cerebrospinal fluid baricity in various groups of humans. The lower baricity in pregnant and immediate postpartum women would favor all hyperbaric solutions to sink downward more rapidly and hypobaric solutions to rise more rapidly in these patients. However, even though statistically significant, one might question how much clinical significance this decreased baricity in CSF at 37°C in the gravid patient (1.0003 vs. 1.0007) would have on the spread of anesthetic solutions injected into the subarachnoid space. Indeed, I would think the temperature of the injected anesthetic solution might play an even greater role, at least immediately after injection. After all, a solution at room temperature of 20 to 22°C would be considerably more dense than at body temperature of 37°C.