Researchers explore associations between dehydration, AIS, and VTE

In patients with acute ischemic stroke (AIS), dehydration upon hospital admission—as signaled by an elevated blood urea nitrogen (BUN)/creatinine (Cr) ratio—may be associated with venous thromboembolism (VTE), according to researchers who published their results in the Journal of the Korean Neurosurgical Society.

“Although venous VTE is frequently related to dehydration, the impact of dehydration on VTE in AIS is not clear. This study investigated whether dehydration, as measured by BUN/Cr ratio, influences the occurrence of VTE in patients with AIS,” wrote the authors.

For this retrospective study, researchers included 182 patients with newly diagnosed AIS who had prolonged hospitalization of at least 4 weeks from January 2012 to December 2013. During follow-up, 9.3% of patients experienced VTE. In two patients, VTE occurred concurrently with deep vein thrombosis and pulmonary embolism.

Researchers found that patients who developed VTE tended to be female and have a higher National Institutes of Health Stroke Scale score, more lower limb weakness, and elevated BUN/CR ratio at admission.

Upon multivariate analysis, they found that a BUN/Cr ratio greater than 15 and severe lower limb weakness were independent risk factors for VTE (odds ratio: 8.75 and 4.38, respectively).

In another recent study of the incidence of VTE in children undergoing elective orthopedic surgery, Georgopoulos et al identified 117,676 patients in the Pediatric Health Information System who were admitted on an ambulatory or inpatient basis during which an elective orthopedic surgery was the primary procedure. Of these patients, 33 had a VTE during index admission, and an additional 41 had VTE upon subsequent readmission.

Researchers found that diagnoses related to electrolyte and fluid disorders had the greatest association with VTE, with VTE occurring in 20 of 1,809 discharges with these diagnoses (1.1%). The most frequent diagnoses included dehydration (four VTE), hyperosmolarity and/or hypernatremia (three VTE), electrolyte disorders not classified elsewhere (two VTE), and diabetes insipidus (two VTE).

The authors concluded, however, that “This is likely an indication of the complex medical picture of the elective pediatric orthopedic patient who is at risk for DVT, rather than an indication of a causative relationship. A link has also been described in adults, with fluid and electrolyte disorders being significantly related to the development of subsequent VTE in those hospitalized for aneurysmal subarachnoid hemorrhage,¹ as well as following acute ischemic stroke.² Whether the observed association in our population represents a cause, or an effect, of VTE is difficult to ascertain.”

References

1. Kshettry VR, Rosenbaum BP, Seicean A, et al. Incidence and risk factors associated with in-hospital venous thromboembolism after aneurysmal subarachnoid hemorrhage. J Clin Neurosci. 2014;21:282–286.
2. Kelly J, Hunt BJ, Lewis RR, et al. Dehydration and venous thromboembolism after acute stroke. QJM. 2004;97:293–296.