Salt wasting, hypotension, polydipsia, and hyponatremia and the level of spinal cord injury

Abstract

Study Design: Case control. Objective: To test the reported correlation of hypotension, polydipsia, and hyponatremia with higher levels of spinal cord injury (SCI). Setting: A Veterans Administration Hospital, USA. Methods: The records of men who were paralyzed owing to trauma at any spinal cord level with motor complete lesions (ASIA A or B) and who received an annual physical and laboratory examination were reviewed for age, duration of paralysis, level of paralysis, blood pressure (BP), serum sodium, and 24 h urinary volume, creatinine, and sodium. Creatinine clearance and fractional excretion of sodium (FcNa) were calculated. Spearman rank-order correlations (r s ) were carried out. Results: Patients were aged 25 to 88 years, median 56 years, paralyzed 2-61 years, median 26 years, with levels of paralysis ranging from C2 to L4, median T4, n ¼ 111. From lower to higher levels of paralysis FcNa increased (0.4-7.3%), mean BP diminished (132-66 mmHg), urine volume increased (600-5400 ml), and serum sodium was reduced (148-129 mEq/l) -r s ¼ 0.29, 0.49, À0.22, and 0.23, respectively. Increasing 24 h urinary volumes correlated with lower serum sodium concentrations but higher creatinine clearance, r s ¼ À0.28, 0.24. Increasing 24 h urinary sodium improved creatinine clearance, r s ¼ 0.37. P-values ranged from o0.05 to o0.001. Conclusion: Higher levels of SCI correlate with reduced sodium conservation, hypotension, polydipsia, and hyponatremia. Greater water intake raises creatinine clearance but lowers serum sodium. Greater salt intake increases creatinine clearance.

Correction of orthostatic hypotension by respiratory effort

“…Supplementation of salt intake to provide adequate substrate for this hormonal recruitment will correct volume depletion and further ameliorate OH. 3 These simple nonpharmacological measures can improve quality of life for the OH patients.…”

Orthostatic hypotension in the first month following acute spinal cord injury

“…8,10 A variety of factors may predispose SCI individuals to OH including impaired baroreflex function 16,17 smaller plasma volumes, hyponatremia 18,19 and cardiovascular deconditioning, 20 especially in the early period following SCI, owing to prolonged periods of bed rest. Any combination of these factors following SCI is likely to increase the likelihood and severity of OH.…”

Risk factor analysis for low blood pressure and hyponatremia in acutely and subacutely spinal cord injured patients

“…[1][2][3][4][5][6] SCI often have unstable blood pressure (BP), bowel bladder dysfunction, gastrointestinal motility disorder and electrolyte disorder because normal sympathetic output is disrupted. 6 Hypotension and hyponatremia associated with sympathetic dysfunction are major complications during the acute stage after traumatic cervical SCI.…”

“…6 Hypotension and hyponatremia associated with sympathetic dysfunction are major complications during the acute stage after traumatic cervical SCI. [1][2][3][4][5][6] These have been shown to be associated with worse outcomes such as secondary SCI, faint, pulmonary edema and rarely cardiac arrest, 4,5 so they must be treated aggressively as needed. Prediction of these complications is very important for planning rehabilitation and for proper medical care, however, there are few studies mentioning the risk factors of them.…”