Indocyanine Green Administration May Cause an Exaggerated Peripheral Oxygen Desaturation in the Presence of Liver Disease—An Underemphasized Observation

  SFX Search  Permissions and Reprints

Microscope-integrated indocyanine green video angiography (ICG-VA) is used to assess the completeness of clipping and cerebral vascular flow during aneurysm surgery.[1] It is a more practical and less time-consuming alternative to intraoperative digital subtraction angiography (DSA). ICG has been reported to cause a decrease in peripheral oxygen saturation (SpO2).[2] [3] [4]

We report a 48-year-old male who presented with complaints of holocranial throbbing headache for 1 month without any history of seizures or focal neurological deficit. The patient was a known alcoholic for the past 20 years. Liver function test showed hyperbilirubinemia and elevated serum transaminases. Noncontrast computed tomography brain revealed subarachnoid hemorrhage. The patient was found to have two aneurysms in the anterior cerebral circulation, one in the anterior communicating artery and one in the right M1 middle cerebral artery, on a DSA scan. He was scheduled for a craniotomy and clipping of both aneurysms. ICG (Aurogreen, Aurolab, Madurai, Tamil Nadu, India) at a dose of 0.25mg/kg was administered after the placement of a permanent clip to ascertain the absence of residual flow through the aneurysm. The intraoperative course was uneventful and the patient's trachea was extubated in the operating room, after the surgery. Postoperative DSA showed a left distal anterior cerebral artery (DACA) aneurysm, which was not detected prior to the surgery.

The patient was then scheduled for clipping of the DACA aneurysm, a week after the first surgery. Intraoperatively, ICG was administered intravenously, in the same recommended dose (0.25 mg/kg) after placement of the permanent clip. The SpO2 dropped to 92% from a baseline of 98%, immediately after the administration of the dye without any change in the signal quality of the SpO2 waveform. This decrease in saturation was transient and lasted for approximately one minute. There was no concurrent hemodynamic disturbance or change in end-tidal carbon dioxide. There was no other significant intraoperative event and tracheal extubation was performed in the operating room. In spite of the fact that the same SpO2 probe was used, no incidence of desaturation was noted during ICG administration for the first surgery. However, the half-life of ICG may be substantially prolonged in patients with liver disease.[5] Although the exact duration of the increase in elimination half-life of ICG in the presence of liver disease has not been quantified in literature, we believe that the cumulative effect of the residual nonmetabolized ICG from the first surgery and the additional ICG administered during the second surgery could be a plausible explanation for the observed desaturation during the second surgery and not the first one. Altered liver function resulting in reduced clearance of the dye might have been responsible for its accumulation and subsequent peripheral oxygen desaturation when it was administered the second time. This hypothesis, however, merits larger, well-designed studies for its investigation.

ICG is a water-soluble, inert, fluorescent dye with a very high hepatic extraction and minimal systemic toxicity. It binds to albumin and distributes rapidly after injection. It has no interaction with neuronal tissue rendering it pharmacodynamically inert in the brain. ICG is exclusively metabolized by the liver and excreted unchanged into bile without any enterohepatic re-circulation. The clearance occurs by a rapid exponential decay of plasma levels followed by a slower prolonged decay.[6] ICG is the only Food and Drug Administration-approved near-infrared fluorophore making it an invaluable angiographic tool in neurosurgery; especially in aneurysmal surgeries. The recommended injectable dose of ICG for angiography is between 0.2 and 0.5 mg/kg, with a maximum dose of 5 mg/kg.[1]

The absorption spectrum of ICG ranges from 600 to 850 nm, with an absorption spectral peak at 805 nm and an emission peak at 835 nm. However, ICG absorbs a significant amount of red light at approximately 660 nm also, and the shift of the absorption peak toward the red end of the spectrum appears to be dose-dependent.[4] [7] This may result in a reduced detection of traversed red light by the photo sensor, which may in turn be falsely attributed to an increased concentration of deoxygenated hemoglobin in the arterial system. The short half-life of ICG (150–180 seconds) probably accounts for the evanescent nature of this observation.[4] A transient increase in regional cerebral SpO2, measured using near infrared spectroscopy following intravenous administration of ICG, has also been reported.[6] [7] [8]

Although peripheral oxygen desaturation after administration of ICG has been reported in the literature, it is not listed as one of the adverse effects in this particular manufacturer's pamphlet. The effect of this transient desaturation on overall patient outcomes is not known. It is desirable that anesthesiologists be aware of this interaction and not be unduly alarmed by this observation. However, exercising caution seems prudent when relatively higher doses of ICG are administered, on more than one occasion, within a short span of time, especially in the presence of liver disease.

Publication History

Article published online:
20 January 2023

© 2023. Indian Society of Neuroanaesthesiology and Critical Care. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

Thieme Medical and Scientific Publishers Pvt. Ltd.
A-12, 2nd Floor, Sector 2, Noida-201301 UP, India

留言 (0)

沒有登入
gif