Optimising Circulating Blood Volume after Subarachnoid Haemorrhage
11 / 2005 - unknown
BACKGROUND A subarachnoid haemorrhage (SAH) is a subset of stroke that carries a poor prognosis. Delayed cerebral ischaemia (DCI) is a frequent complication that importantly contributes to the poor outcome after SAH. An important risk factor for DCI is hypovolaemia. Hypovolaemia occurs frequently after SAH and is poorly detected on clinical signs only. Current practice is tailoring fluid management according to bedside fluid balances. In a series of 50 patients we found that with this strategy still many patients have periods of hypovolaemia. Moreover, hypervolaemia also occurred frequently. Pulse dye densitometry allows minimally invasive measurement of the circulating blood volume. Regular measurements of the actual volume status with this technique may be a better strategy to guide fluid therapy after SAH. OBJECTIVE To assess in patients with SAH the effectiveness in maintaining normovolemia of a strategy that tailors fluid management according to regular measurement of the actual volume status. Subarachnoid haemorrhage (SAH) from a ruptured aneurysm is a subset of stroke that occurs at a relatively young age (half the patients are less than 55 years old), and carries a high case fatality (50%) and morbidity (25%).(1) Patients with a SAH are treated by a multidisciplinary team of neurologists, neurosurgeons, and intensivists in medium or intensive care facilities. To prevent rebleeding the aneurysm is obliterated as soon as possible, either by a neurosurgical procedure in which a metal clip is placed over the neck of the aneurysm, or by an endovascular procedure by radiologists in which platinum coils are inserted inside the aneurysm. In patients who have survived the initial hours after SAH and in whom the aneurysm has been occluded, delayed cerebral ischaemia (DCI) is one of the most important factors determining outcome. DCI occurs in one third of patients and starts usually 4 to 10 days after the SAH. OBJECTIVE To study if tailoring the fluid management through regular measurements of the actual volume status by means of pulse dye densitometry in patients with aneurysmal subarachnoid haemorrhage (SAH) leads to improved maintenance of normovolaemia. PRESENT HEALTHCARE PROBLEM Subarachnoid haemorrhage from an intracranial aneurysm is a subset of stroke. Subarachnoid haemorrhage occurs in relatively young people (mean age 55 years) and carries a high case fatality (50%) and morbidity (25%). Because of the young age and the poor prognosis, the population based loss of productive life years from subarachnoid haemorrhage is as large as that from cerebral infarction, the most common type of stroke.(4) In patients who have survived the initial hours after the haemorrhage and in whom the aneurysm has been occluded, DCI is the most important complication leading to poor outcome. Because patients with SAH are relatively young, permanent dependency induces long lasting burden and costs. PILOT STUDY We have recently performed a pilot study in 50 consecutive patients with aneurysmal subarachnoid haemorrhage who were all treated according to a standardised fluid management protocol. Fluid intake was based on regular (4 times per day) calculations of the fluid balance and aimed at maintaining normovolaemia.