Hyponatremia in elderly patients with fractures around the hip; role of glutamate (CSF glutamate study)

Abstract

Background & objective: Hyponatremia is the most common electrolyte disorder and is a predictor of osteoporosis, inflammation and cognitive dysfunction leading to falls in the elderly patients. We compared glutamate levels in normonatremic elderly patients with those with hyponatremia, admitted with osteoarthritis, to find correlation between the cognitive status with cerebrospinal fluid (CSF) glutamate as a biomarker for hyponatremia. Methodology: In an observational prospective study; 70 patients, more than 70 y of age, admitted to trauma unit of Assiut University Hospital with fractures around the hip, were investigated for the frequency of on-admission hyponatremia. The CSF glutamate level was determined using radio-immune assay. We compared glutamate level in 18 hyponatremic patients with 10 normonatremic elderly patients admitted with osteoarthritis for elective joint replacement (control group) to find correlation between the cognitive status assessed by Modified Mini-Mental State (3MS) examination and CSF glutamate as a biomarker for hyponatremia. Results: Hyponatremia is highly prevalent in elderly with fractures around the hip; we recorded it in 41.4% of the study sample. Most patients were females (62.86%). CSF glutamate was significantly increased in hyponatremic patients than the controls (P < 0.001). Conclusion: Prevalence of hyponatremia is high in old aged patients probably due to due to prevalent hot weather in the south of Egypt. CSF glutamate level can be a marker for mild cognitive impairment caused by hyponatremia. Abbreviations: 3MS: Modified Mini-Mental State examination; CSF: cerebrospinal fluid; RPM: revolutions per minute; ELISA: enzyme-linked immunosorbent assay; SD: standard deviation Key words: Geriatric anesthesia; Chronic Disease; Cognition Disorders / blood; Cognition Disorders / etiology; Glutamic Acid / metabolism; Hyponatremia / blood; Hyponatremia / complications; Hyponatremia / psychology; Inappropriate ADH Syndrome / complications; 3MS Citation:  Kotb HI, Hassan A, Sayed AA, Seddik MI, Maghraby HH, Kamel EZ. Hyponatremia in elderly patients with fractures around the hip; role of glutamate (CSF glutamate study). Anaesth. pain intensive care 2022;26(3):332-337 DOI: 10.35975/apic.v26i3.1900 Received: November 28, 2020; Reviewed: December 25, 2020; Accepted: April 25, 2022