From the Guidelines
Cerebral salt wasting should be treated with aggressive volume resuscitation using crystalloid or colloid agents, and hypertonic saline solution can be effective in correcting hyponatremia and improving regional cerebral blood flow. The management of cerebral salt wasting is crucial to prevent poor outcomes, particularly in patients with poor clinical grade, ruptured anterior communicating artery aneurysms, and hydrocephalus 1. The condition is characterized by excessive secretion of natriuretic peptides, leading to hyponatremia and volume contraction.
Key Considerations
- Hyponatremia can develop from different mechanisms after aneurysmal subarachnoid hemorrhage (aSAH), and cerebral salt wasting is one of the causes 1.
- The diagnosis of cerebral salt wasting is more common in patients with poor clinical grade, ruptured anterior communicating artery aneurysms, and hydrocephalus, and it may be an independent risk factor for poor outcome 1.
- Uncontrolled studies suggest that aggressive volume resuscitation can ameliorate the effect of cerebral salt wasting on the risk of cerebral ischemia after aSAH 1.
- Hypertonic saline solution appears to increase regional cerebral blood flow, brain tissue oxygen, and pH in patients with high-grade aSAH 1.
Treatment Options
- Aggressive volume resuscitation using crystalloid or colloid agents can help correct hyponatremia and volume depletion 1.
- Hypertonic saline solution (3% NaCl) can be effective in correcting hyponatremia and improving regional cerebral blood flow 1.
- Fludrocortisone can help correct negative sodium balance and reduce the need for fluids 1.
- Hydrocortisone can reduce natriuresis and the rate of hyponatremia in aSAH patients 1.
From the Research
Definition and Diagnosis of Cerebral Salt Wasting
- Cerebral salt wasting (CSW) is a syndrome of hypovolemic hyponatremia caused by natriuresis and diuresis 2.
- The mechanisms underlying CSW have not been precisely delineated, although existing evidence strongly implicates abnormal elevations in circulating natriuretic peptides 2.
- The key in diagnosis of CSW lies in distinguishing it from the more common syndrome of inappropriate secretion of antidiuretic hormone, with volume status being crucial for making this distinction 2.
Clinical Characteristics and Diagnostic Criteria
- The essential features of CSWS are hyponatremia, hypovolemia, and increased urine output 3.
- A cerebral lesion and a large natriuresis without a known stimulus to excrete so much sodium constitute the essential two elements of CSW 4.
- Three fallacies concerning cerebral salt wasting are stressed: first, cerebral salt wasting is a common disorder; second, hyponatremia should be one of its diagnostic features; and third, most patients have a negative balance for Na when the diagnosis of cerebral salt wasting is made 4.
Treatment and Management
- Volume and sodium repletion are the goals of treatment of patients with CSW, and this can be performed using some combination of isotonic saline, hypertonic saline, and mineralocorticoids 2.
- Treatment regimens may be determined based on the acuity and severity of hyponatremia and hypovolemia as well as evident symptoms and signs 3.
- Neurologically injured patients receiving hypertonic sodium therapy with a high chloride load are at risk of developing hyperchloremia and acute kidney injury (AKI) 5.