Cerebral aneurysm – Electrolytes
Aneurysmal subarachnoid hemorrhage occurs in approximately 1 per 10,000 persons in the United States every year, accounting for 5–15% of all strokes. The overall case fatality of all‐cause SAH is as high as 50%. Aneurysmal SAH carries a 30-day mortality rate of 45%. Of those who survive, nearly 1/3 suffers significant and permanent neurological disability.
Cerebral vasospasm remains a major cause of death and disability in patients who experience subarachnoid hemorrhage (SAH) from a ruptured cerebral aneurysm. Despite nearly 50 years of research, there remains a paucity of effective therapies to prevent or reverse this condition. Other major complications include: re-bleeding, hydrocephalus, cardiopulmonary dysfunction, and electrolyte disturbances; of note, non-neurological complications of SAH develop in more than half of patients.
Electrolyte disturbances
SAH is frequently accompanied by hyponatremia, hypokalemia, hypocalcamia, and hypomagnesemia. Hyponatremia develops in approximately 30% of cases as a result of either the cerebral salt wasting (CSW) syndrome or the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). The cerebral salt wasting syndrome is thought to be caused by the secretion of brain and atrial natriuretic hormone, which leads to a negative sodium balance, hyponatraemia, and intravascular volume depletion.
Apart from infusions of normal saline (or rarely hypertonic saline) to maintain euvolemia, therapeutic options for the cerebral salt wasting syndrome are limited. Some studies have shown that the administration of fludrocortisone and hydrocortisone can prevent or reduce intravascular volume depletion and decreased the incidence of negative sodium balance.
SIADH is accompanied by retention of excess free water. Stringent fluid restriction would appear to be the treatment of choice; however, salt-containing infusions are usually used during SAH to ensure a normal to high intravascular volume.
Nontraumatic Intracranial hemorrhages including subarachnoid, intraparenchymal and intraventricular hemorrhage, have remarkable mortalities.
The incidence of subarachnoid hemorrhage (SAH) increases with advancing age and is more common among women above 50 years old. The mortality rate 1-month after aneurysmal SAH is about 45%8 and if associated with ICH rises to 52%4 and many of the survivors suffer from significant disabilities. Each year, among the 27,000 patients with SAH in the United States, about half of them die and only <25% have favorable outcomes.
Although the main predictive factor of the outcome is the severity of neurologic morbidity, but nonneurologic complications can also affect the length of stay in Intensive Care Unit (ICU) and hospitalization and the final outcome the patients.
Electrolyte disturbances are common in ICU-admitted patients. Intracranial disorders are associated with dysregulations of serum electrolyte levels. Thus, electrolyte abnormalities are of particular importance in neurosurgical ICU patients.
The studies on the pattern and importance of electrolyte disturbance in SAH patients, have reported conflicting results. Some of them have reported adverse effects of electrolyte abnormalities on the outcome of these patients, while some others did not find such a relationship.
This study evaluates the pattern of electrolyte disturbances in patients with aneurysmal SAH and their impact on the outcome of these patients.
The results of this study show that electrolyte imbalance is a major nonneurologic source of mortality and morbidity after aneurysmal SAH. This study in concert with many others emphasizes the impact of hypernatremia in the acute and subacute phase on the long-term outcome of patients with aneurysmal SAH, and also as well as the few other studies available in the literature highlights the negative effect of hypomagnesemia in the subacute phase on their outcome. These results elucidate that the timely and appropriate management of these abnormalities may further improve the treatment results of aneurysmal SAH. The efficacy of different therapeutic modalities in improving the outcome is an issue that remains to be determined yet. We recommend future studies to evaluate the impact of these treatment regimens and to monitor serum levels of biomarkers such as BNP as well.