Effect of background serum lithium concentrations on the accuracy of lithium dilution cardiac output determination in dogs

Abstract

The LiDCO measurement increased slightly as the serum lithium concentration increased. This error was not clinically relevant and was minimal at a serum lithium concentration of 0.1 mmol/L and modest at a concentration of 0.4 mmol/L. The serum lithium concentration can be reliably predicted from the cumulative lithium dosage if lithium chloride is administered often within a short period.

Continuous cardiac output monitoring via arterial pressure waveform analysis following severe hemorrhagic shock in dogs*

“…In addition, only one lithium dilution was performed to determine CO at each time point to limit the effects of background lithium accumulation. Previous work has demonstrated that as many as 16 doses of lithium can be administered during several hours with minimal impact on CO (16). However, the subjects in our study experienced states of severely decreased CO, and lithium accumulation may have occurred.…”

“…Given the dynamic and rapidly changing nature of CO in severely ill or hemorrhaged patients, frequent determinations of CO may be required. Multiple injections of indicators that are not rapidly cleared from the circulation (indocyanine green, lithium) increase the potential for background interference and tend to overestimate CO (16). Furthermore, frequent dosing with lithium chloride could result in toxicity.…”

Comparison of thermodilution, lithium dilution, and pulse contour analysis for the measurement of cardiac output in 3 different hemodynamic states in dogs

“…Therefore, determination of CO by this method is safe because the lithium‐selective electrode is activated by doses much lower than any pharmacological or toxic dose . In the present study, we calibrated the LiDCO plus 18 times in each dog, which could increase the risk for toxicity or even interfere with the accuracy of the monitor, as a progressive increase in the blood lithium concentration increases the overestimation of CO by LiDCO . However, we observed no sign of toxicity in our animals after recovery from anesthesia.…”

Cardiopulmonary effects of a new inspiratory impedance threshold device in anesthetized hypotensive dogs

“…Blood loss associated with arterial blood withdrawal for _ Qt determination was minimal and estimated at <5% total blood volume. Likewise, the total mean cumulative dose of lithium administered was low (0.029 ± 0.005 mmol kg )1 ), and should not have affected our results (Corley et al 2002;Mason et al 2002).…”