Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0917798 (cerebral ischemia)
 17,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although spinal and epidural blocks provide excellent anaesthesia for many operations, they are frequently accompanied by hypotension. This is largely the result of sympathetic nerve blockade. Excessive hypotension may potentially produce myocardial and cerebral ischaemia, and is associated with neonatal acidaemia in obstetric practice. How to prevent and treat this hypotension has been the subject of much investigation and controversy. One of the mainstays of management is the use of vasopressor agents and those currently available are not perfect. In this review, the role of vasopressor agents is discussed and possible future management strategies are commented upon. Ephedrine was the first agent used for this purpose and it has withstood the test of time: it is the agent against which all others are compared. It remains the first-line agent in obstetric anaesthesia as it does not affect the fetus adversely, but it cannot be relied upon to be 100% successful and other agents must be considered when it is inadequate. It is best given by infusion. In non-obstetric practice, ephedrine has a good track record but again its success rate is less than 100%. As there is no fetus to consider, it may be more appropriate to consider using a pure vasoconstrictor agent such as methoxamine or phenylephrine as a first-line therapy in such cases. This judgment can only be made on an individual patient basis as ephedrine produces a tachycardia while phenylephrine and methoxamine both produce bradycardia.
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PMID:The role of vasopressors in the management of hypotension induced by spinal and epidural anaesthesia. 778 38

A 77-year-old man scheduled for coronary artery bypass grafting underwent left superficial temporal artery-middle cerebral artery anastomosis (STA MCA). Before anesthesia, we planned to insert an intraaortic balloon pump as a perioperative circulatory assist. In addition, a fiberoptic catheter was inserted in the proximity of the right jugular bulb to monitor jugular venous oxygen saturation (Sjv(O2)) as an index of the balance between cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRO2). Continuous infusion of nicorandil was started prior to induction of anesthesia. General anesthesia was induced with remifentanil, propofol and rocuronium, and was maintained with oxygen, air, remifentanil and propofol. After induction of anesthesia, blood pressure decreased from 160/70 mmHg to 100/50 mmHg. There was no abnormality of electrocardiogram. However, Sjv(O2) decreased from 58% to 40%. Ephedrine was immediately injected and continuous infusion of dopamine was started. Blood pressure increased and Sjv(O2) was improved to > 55%. Thereafter, his operative course was uneventful. Sjv(O2) is normally approximately 55-75%. If Sjv(O2) is < 50%, therapy (s) directed at increasing CBF and/or decreasing CMRO2 should be initiated. Sjv(O2) monitoring can be used to determine the minimal blood pressure that should be maintained to avoid cerebral ischemia in the case of STA-MCA.
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PMID:[Monitoring of jugular venous oxygen saturation during superficial temporal artery-middle cerebral artery anastomosis under intraaortic balloon pumping: a case report]. 2519 25