[Do elevated blood and cerebrospinal fluid glucose levels and other factors modify the density of cerebrospinal fluid and the spread of isobaric spinal anesthesia?].

Abstract

When isobaric spinal anesthesia is applied the level of analgesia is of special interest. This level is influenced by many factors of varying importance. One major factor is the relation between cerebrospinal fluid (CSF) density and the density of local anesthetic solutions. The density of CSF changes with the concentrations of its constituents, e.g., glucose or protein. Because glucose concentrations in CSF change in parallel with blood glucose levels, this may have effects on CSF density and the spread of spinal anesthesia. In 43 patients in two groups (diabetic n = 32, non-diabetic n = 11) the influence of CSF density on the analgesia level achieved with isobaric spinal anesthesia was investigated with special reference to increased glucose levels in blood and CSF. The influence of body height and weight, age and CSF protein content were also studied. There were no statistically significant correlations between any of these factors and the extension of analgesia. The mean blockade level was 1.6 segments lower in the non-diabetic group: this difference was statistically not significant (P greater than 0.05). Anesthesia spread faster in the diabetic group, but this difference was also not significant (P greater than 0.05). For bupivacaine 0.5% alone a density of 1.0010 g/cc was found, while for bupivacaine 0.5% with epinephrine (1:200,000) the density measured was 1.0022 g/cc. There is no correlation (r2 = 0.083) between CSF glucose concentration and CSF density, other factors such as sodium, chloride or CO2, apparently being more important. With CSF density ranging between 1.000 and 1.003 g/cc there was no correlation with the blockade level (r2 = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)