It Ain’t Easy Being Green

Is this why they have gone off the rails with the beta carotene and related things? Thoughts for another day.

• Nabil M. Elkassabany, Geralyn M. Meny, Rafael R. Doria, Catherine Marcucci; Green Plasma—Revisited. Anesthesiology 2008; 108:764–765 doi: https://doi.org/10.1097/ALN.0b013e3181672668

A search for “green plasma” at pubmed turns up 130 articles from 1965 to present. A search for green plasma (without the marks) or ‘green plasma’ at the same place turns up 1280 articles from 1948 to present and these appear to include names of authors and lord knows what else.

Also interesting is something called Indocyanine Green which regularly turns up in searches for green plasma. I’ve read very little about it. This showed up as a related article to ‘Green Plasma – Revisited.’

The inadvertent intravascular injection of a local anesthetic during epidural anesthesia is an uncommon but potentially serious complication. Epinephrine, the most commonly used marker, does not provide sufficient sensitivity to exclude intravascular injection in all patient populations. The dye indocyanine green (ICG) has been proposed as an alternative marker. It has been demonstrated that ICG could be used to detect intravascular injections with a simple transcutaneous spectrophotometric technique. Although the safety of intravenous ICG is well documented, its neurotoxic potential requires careful study given the probability of inadvertent intrathecal injection during test injections used to verify epidural catheter placement…Given this apparent neurotoxicity, ICG should not be used when intrathecal or nerve root injection is possible.

Friederike B. Dietz, Richard A. Jaffe; Indocyanine Green: Evidence of Neurotoxicity in Spinal Root Axons. Anesthesiology 2003; 98:516–520 doi: https://doi.org/10.1097/00000542-200302000-00034