Julie E Farrar, Sylvia S Stefanos, Luis Cava, Tyree H Kiser, Scott W Mueller, Robert Neumann, Paul M Reynolds, Deb S Sherman, Robert MacLaren
{"title":"Correlation Between Serum and CSF Concentrations of Midazolam and 1-Hydroxy-Midazolam in Critically Ill Neurosurgical Patients.","authors":"Julie E Farrar, Sylvia S Stefanos, Luis Cava, Tyree H Kiser, Scott W Mueller, Robert Neumann, Paul M Reynolds, Deb S Sherman, Robert MacLaren","doi":"10.1177/10600280241271130","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Midazolam (MZ) is commonly used in critically ill neurosurgical patients. Neuro-penetration of MZ and its metabolite, 1-hydroxy-midazolam (1-OH-MZ), is not well characterized.</p><p><strong>Objective: </strong>This study evaluated correlations between serum and cerebrospinal fluid (CSF) concentrations of MZ and 1-OH-MZ and assessed implications on patient sedation.</p><p><strong>Methods: </strong>Adults in the neurosurgical intensive care unit (ICU) with external ventricular drains receiving MZ via continuous infusion were prospectively studied. Serum and CSF samples were obtained 12-24 h and 72-96 h after initiation, and concentrations were determined in duplicate by high-performance liquid chromatography with tandem mass spectrometry. Bivariate correlation analyses used Pearson coefficient.</p><p><strong>Results: </strong>A total of 31 serum and CSF samples were obtained from 18 subjects. At sampling, mean MZ infusion rate was 3.9 ± 4.4 mg/h, and previous 12-h cumulative dose was 51.4 ± 78.2 mg. Mean concentrations of MZ and 1-OH-MZ in serum and CSF were similar between timepoints. Similarly, ratios of 1-OH-MZ to MZ in serum and CSF remained stable over time. Serum MZ (126.2 ± 89.3 ng/mL) showed moderate correlation (r<sup>2</sup> = 0.68, P < 0.001) with serum 1-OH-MZ (17.7 ± 17.6 ng/mL) but not CSF MZ (3.9 ± 2.5 ng/mL; r<sup>2</sup> = 0.24, P = 0.005) or CSF 1-OH-MZ (2.5 ± 0.6 ng/mL; r<sup>2</sup> = 0.47, P = 0.30). CSF MZ did not correlate with CSF 1-OH-MZ (r<sup>2</sup> = 0.003, P < 0.001). Mean serum ratio of 1-OH-MZ to MZ (0.14 ± 0.2 ng/mL) did not correlate with CSF ratio (1.06 ± 0.83 ng/mL; r<sup>2</sup> = 0.06, P = 0.19). Concentrations and ratios were unrelated to MZ infusion rate or 12-h cumulative dose. Sedation was weakly correlated with CSF 1-OH-MZ, but not with serum MZ, serum 1-OH-MZ, or CSF MZ.</p><p><strong>Conclusion and relevance: </strong>Continuous infusions of MZ result in measurable concentrations of MZ and 1-OH-MZ in CSF; however, CSF concentrations of MZ and 1-OH-MZ poorly represent serum concentrations or dosages. Accumulation of MZ and 1-OH-MZ in serum or CSF over time was not evident. Concentrations of MZ and 1-OH-MZ do not predict sedation levels, reinforcing that pharmacodynamic assessments are warranted.</p>","PeriodicalId":2,"journal":{"name":"ACS Applied Bio Materials","volume":null,"pages":null},"PeriodicalIF":4.6000,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Applied Bio Materials","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1177/10600280241271130","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, BIOMATERIALS","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Midazolam (MZ) is commonly used in critically ill neurosurgical patients. Neuro-penetration of MZ and its metabolite, 1-hydroxy-midazolam (1-OH-MZ), is not well characterized.
Objective: This study evaluated correlations between serum and cerebrospinal fluid (CSF) concentrations of MZ and 1-OH-MZ and assessed implications on patient sedation.
Methods: Adults in the neurosurgical intensive care unit (ICU) with external ventricular drains receiving MZ via continuous infusion were prospectively studied. Serum and CSF samples were obtained 12-24 h and 72-96 h after initiation, and concentrations were determined in duplicate by high-performance liquid chromatography with tandem mass spectrometry. Bivariate correlation analyses used Pearson coefficient.
Results: A total of 31 serum and CSF samples were obtained from 18 subjects. At sampling, mean MZ infusion rate was 3.9 ± 4.4 mg/h, and previous 12-h cumulative dose was 51.4 ± 78.2 mg. Mean concentrations of MZ and 1-OH-MZ in serum and CSF were similar between timepoints. Similarly, ratios of 1-OH-MZ to MZ in serum and CSF remained stable over time. Serum MZ (126.2 ± 89.3 ng/mL) showed moderate correlation (r2 = 0.68, P < 0.001) with serum 1-OH-MZ (17.7 ± 17.6 ng/mL) but not CSF MZ (3.9 ± 2.5 ng/mL; r2 = 0.24, P = 0.005) or CSF 1-OH-MZ (2.5 ± 0.6 ng/mL; r2 = 0.47, P = 0.30). CSF MZ did not correlate with CSF 1-OH-MZ (r2 = 0.003, P < 0.001). Mean serum ratio of 1-OH-MZ to MZ (0.14 ± 0.2 ng/mL) did not correlate with CSF ratio (1.06 ± 0.83 ng/mL; r2 = 0.06, P = 0.19). Concentrations and ratios were unrelated to MZ infusion rate or 12-h cumulative dose. Sedation was weakly correlated with CSF 1-OH-MZ, but not with serum MZ, serum 1-OH-MZ, or CSF MZ.
Conclusion and relevance: Continuous infusions of MZ result in measurable concentrations of MZ and 1-OH-MZ in CSF; however, CSF concentrations of MZ and 1-OH-MZ poorly represent serum concentrations or dosages. Accumulation of MZ and 1-OH-MZ in serum or CSF over time was not evident. Concentrations of MZ and 1-OH-MZ do not predict sedation levels, reinforcing that pharmacodynamic assessments are warranted.