A large number of clinical conditions are associated with a transient or permanent disturbance of brain function. Common to all of them is that, in some way, brain metabolism is changed from the normal. These changes cover a vast spectrum, ranging from the subtle alterations of metabolism encountered in mental disease to those underlying death and dissolution of cells in conditions of oxygen lack. This communication is concerned with brain metabolism in the critically ill with emphasis on conditions of hypoglycemia, hypoxia, and ischemia. We begin by briefly recalling the salient features of brain metabolism in the healthy individual. Since clinicians caring for critically ill patients take an interest in factors that may aggravate the primary disease and in measures that may prevent or minimize its final effect on the brain, we will also briefly consider how brain metabolism is influenced by potentially harmful factors (hyperthermia, anxiety and stress, and tissue acidosis due to CO2 retention) as well as by measures that are often instituted to ameliorate the effects of hypoxia and ischemia (hypothermia, administration of anesthetics and sedatives). We refer the reader to selected references with preference to recent articles reviewing previous literature.

Brain↗

PubMedDate not supplied

Cerebral oxygen consumption and blood flow in hypoxia: influence of sympathoadrenal activation.

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Adrenal Glands↗

PubMedDate not supplied

Extended unilateral anesthesia. New technique or paravertebral anesthesia?

BACKGROUND AND OBJECTIVES: The authors previously reported a case in which injection of local anesthetic posterior to the endothoracic fascia at the T11 vertebral level gave rise to extended analgesia in thoracic and lumbar dermatomes. They now report a study in which this type of anesthesia was used in patients undergoing herniorrhaphy. METHODS: A 12-mL dose of 2% mepivacaine was injected at the T11 level posterior to the endothoracic fascia in 15 patients. RESULTS: On average, seven dermatomes could be blocked with this dose and with a single injection. Nine patients experienced adequate analgesia and underwent operation with no additional sedation. In three patients the block resulted in inadequate analgesia, and additional sedative drugs were used. Three patients experienced no analgesia and were given general anesthesia CONCLUSION: Injection of local anesthetic posterior to the endothoracic fascia resulted in extended unilateral anesthesia that was adequate for herniorrhaphy in 9 of the 15 patients (60%) studied.

Adult↗