title: A case-cohort study with propensity score matching to evaluate the effects of mannitol on venous thromboembolism.
abstract: Mannitol has been shown to damage endothelial cells and activate coagulation pathways leading to intravascular thrombosis. Dehydration and hemagglutination have also been associated with mannitol use, although the risk of clinically evident venous thromboembolism (VTE) disease is not well-defined. The aim of this study was to compare the risk of VTE in critically ill neurological patients who received mannitol compared to only hypertonic saline. A case-cohort study design with propensity score matching was used to evaluate the risk of VTE among patients who received mannitol compared to those who received hypertonic saline alone. The odds of thrombosis were evaluated by the Cochran-Mantel-Haenszel method and conditional logistic regression was used to adjust for year of treatment. Ninety-one of 330 patients (27.6%; 95% confidence interval [CI] 23-33%) developed a VTE; however, the yearly proportion remained unchanged over the 8 year study period. Cumulative use of mannitol declined and use of hypertonic saline increased significantly. The odds of thrombosis for those exposed to mannitol compared to hypertonic saline alone was 1.11 (95% CI 0.65-1.73; p=0.75). This remained insignificant after adjusting for year of injury. In conclusion, despite a significant change in the pattern of osmotic therapy used at our institution, the proportion of patients with VTE remained unchanged. We found no evidence that mannitol use was associated with VTE compared to hypertonic saline alone.
authors.affiliation: Department of Neurosurgery, University of Michigan Medical School, 1500 East Medical Center Drive, Room 3552 TC, Ann Arbor, MI 48109-5338, USA. Electronic address: jflet10121@aol.com.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Fletcher
authors.affiliation: Department of Neurosurgery, University of Michigan Medical School, 1500 East Medical Center Drive, Room 3552 TC, Ann Arbor, MI 48109-5338, USA.
authors.forename: Allison M
authors.initials: AM
authors.lastname: Kade
authors.affiliation: Department of Neurosurgery, University of Michigan Medical School, 1500 East Medical Center Drive, Room 3552 TC, Ann Arbor, MI 48109-5338, USA.
authors.forename: Kyle M
authors.initials: KM
authors.lastname: Sheehan
authors.affiliation: Department of Neurosurgery, University of Michigan Medical School, 1500 East Medical Center Drive, Room 3552 TC, Ann Arbor, MI 48109-5338, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Wilson
mesh_terms: D015331:Cohort Studies; D004234:Diuretics, Osmotic / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008353:Mannitol / Q000009:adverse effects / Q000627:therapeutic use*; D008875:Middle Aged; D016017:Odds Ratio; D010818:Practice Patterns, Physicians'; D012306:Risk; D012462:Saline Solution, Hypertonic / Q000627:therapeutic use; D012720:Severity of Illness Index; D054556:Venous Thromboembolism / Q000453:epidemiology*
chemical_list: D004234:Diuretics, Osmotic; D012462:Saline Solution, Hypertonic; D008353:Mannitol
keywords: Deep venous thrombosis; Hypertonic saline; Mannitol; Osmotic therapy; Thrombosis; Venous thromboembolism