To maintain adequate cerebral perfusion, it is important to maintain normovolemia. The practice of keeping neurological patients dehydrated to minimize cerebral edema is outdated, and in head-injured patients is associated with poor outcome . Fluid balance tallying total input and output should be monitored daily, and insensible loss of 500-800 ml per day should be allowed. Patients with head injury often suffer multiple injuries that may result in significant blood loss, contributing to hypovolemia and hypotension. On the other hand, patients who suffer SAH can develop acute decrease in circulating blood volume unrelated to blood loss. Patients with hemorrhagic or ischemic stroke may also be hypovolemic, and the volume status cannot be assessed by the presence or absence of systemic hypertension. A thorough history and clinical examination is crucial to the establishment of the correct diagnosis. To ensure normovolemia, isotonic fluids or normal saline should be given, although the latter, when given in large amounts, would inevitably lead to hyperchloremic metabolic acidosis.
In patients with partially disrupted blood-brain barrier (BBB), colloids have a theoretical advantage, and their benefits in reducing edema can be demonstrated in experimental focal cerebral ischemia. However, there is no clinical evidence of its efficacy. Moreover, metaanalysis of clinical trials suggests that the use of colloids for resuscitation of critically ill patients is associated with an increase in mortality. If colloids are to be used, albumin is preferred to hetastarch, as the latter can interfere with coagulation system and may cause bleeding in susceptible neurological patients, despite being given in small amounts. Monitoring of central venous pressure or pulmonary wedge pressure would help to guide fluid therapy, particularly in the management of patients in vasospasm. Anemia should be treated promptly to maintain adequate oxygen delivery. The
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Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...