Anesthesiology
-
Eye injuries after anesthesia, although infrequent, may result in visual impairment. Previous studies have not defined the risk factors associated with these injuries. To study the cause of these injuries and to determine incidence data, the authors reviewed the records from a 4.5-y period of patients who sustained eye injuries after anesthesia and nonocular surgery. ⋯ For reasons not understood, eye injuries are more common in patients who are older or who undergo lengthier procedures. The cause of injury was usually not determined by the authors' methods. Until the mechanisms producing perioperative eye injuries are better understood, it is difficult to identify strategies to prevent this type of injury.
-
The risk of bacterial contamination related to epidural analgesia in patients cared for in the intensive care unit has not been assessed. Thus the authors studied patients who received care in the intensive care unit who were given epidural analgesia for more than 48 h to determine the rates of local, epidural catheter, and spinal space infection and to identify risk factors. ⋯ The risk of epidural analgesia-related infection in patients in the intensive care unit seems to be low. The presence of two local signs of inflammation is a strong predictor of local and epidural catheter infection.
-
The effects of epidural injection on intracranial pressure (ICP), lumbar epidural pressure, cerebral blood flow (CBF), and spinal cord blood flow (SCBF) were studied after acutely increased ICP in swine. ⋯ In this porcine model, epidural injection increased ICP. With increased ICP at baseline, more pronounced increases in ICP followed epidural injection. With increased baseline ICP, both epidural elastance and resistance increased compared with controls. The CBF and SCBF were markedly reduced immediately after local anesthetic injection into the epidural space.
-
Previous work showed that incorporation of dexamethasone (0.05 weight/weight percentage) into bupivacaine microspheres prolonged blockade by eight to 13 times compared with that produced by bupivacaine microspheres alone. The determinants of dexamethasone's block-prolonging effect were examined and reported here. ⋯ Glucocorticoids prolong blockade from bupivacaine microspheres. The mechanism appears unrelated to the kinetics of bupivacaine release in vivo.
-
The clinical application of intraoperative motor-evoked potentials (MEPs) has been hampered by their sensitivity to anesthetics. Recently, to overcome anesthetic-induced depression of myogenic MEPs, multiple stimulus setups with a paired or a train of pulses for stimulation of the motor cortex were reported. However, the effects of anesthetics on MEPs induced by these stimulation techniques are unknown. ⋯ Application of double or triple stimulation of the motor cortex increases the success rate of MEP recording and its amplitude during isoflurane anesthesia in rats. However, these responses are suppressed by isoflurane in a dose-dependent manner.