Statistical correlation of fentanyl plasmatic concentration determined by a lc-ms/ms method with the evolution of pain intensity

Despite over 30 years of pain management research conducted in many countries, health services are still struggling to solve the problem of "oligoanalgesia" in the emergency department (ED). Thus, the current work aimed at a study focused on the evaluation of pain treatment in patients presented in the Emergency Service of the "St. Spiridon" County Clinical Hospital in Iasi, Romania, who were treated with fentanyl citrate (FC) using a liquid chromatography tandem mass spectrometry method (LC-MS/MS). Two therapeutically important values were obtained after fentanyl dosing: peak area (peak of analgesic action) and final concentration (completion of analgesia). Both values were correlated with the time when fentanyl was administered and with the evolution of pain intensity before and after its administration. The obtained results showed an inversely proportional correlation between fentanyl plasma concentration and the scores obtained in the 2nd and 3rd assessment of pain intensity. Despite this, a clear improvement in pain was obvious, especially after the 2nd and 3rd assessment. We can conclude that the intensity of the desired effect correlates with the concentration of the drug at the site of action, and not with its plasma concentration.