To compare between intermittent bolus and traditional continuous drip of 3%NaCl in patients with severe symptomatic hyponatremia in Rajavithi Hospital.

Background: Hyponatremia is the most common electrolyte imbalance in clinical practice, associated with increased mortality and length of stay. In 2014,European guideline have recommended promp infusion of 3%NaCl 150 ml in 20 minutes to raise plasma Na to 5 mmol/L and improve symptoms. The recommendation was the result of studies with small numbers of patients, and expert opinions.

Methods: A single center opened-label randomized controlled-trial,we will randomly assign 40 patients with severe symptomatic hyponatremia (plasmaNa<125mmol/L) in Rajavithi Hospital into two groups:

First group receive intermittent bolus of 3%NaCl 150 ml in 30 minutes and follow plasma sodium until achieve target of goal plasma sodium = 5 mmol/L in 6 hours (no more than 12 mmol/L in 24 hr and 18 mmol/L in 48 hr),another receive traditional continuous drip of 3%NaCl start with rate = 1ml/kg/hr and follow plasma sodium every 1 hour until achieve target of plasma sodium 5 mmol/L in 6 hours .The primary end point is change in plasma sodium in 6 hours and improvement of glasglow coma scale.The secondary end points are change in plasma sodium in 24,48 hours,overcorrection rate in 24 and 48 hours ,ODS rate ,hospitality days and mortality rate.

Inclusion Criteria:

• Patients in Rajavithi Hospital
• Age from 18 years
• Plasma Na < 125 mmol/l with glucose-corrected
• Severe symptomatic hyponatremia (Vomitting ,Coma ,Somnolence)

Exclusion Criteria:

• Systolic BP < 90 mmHg Or MAP< 70 mmHg
• Pregnancy or Lactation
• Congestive Heart Failure or Volume overload
• Lung congestionfrom CXR
• Chronic renal failure patients with edema
• Cirrhosis patients with edema
• Patients with coronary artery disease
• Patients with brain injuries
• Deny consent