Our results suggest that midazolam and propofol sedation have different effects on dynamic cerebral autoregulation despite causing equivalent decreases in steady-state CBF velocity. Only midazolam sedation is likely to improve dynamic cerebral autoregulation.

This case suggests that spinal anesthesia, even with an ordinary dose of hyperbaric 0.5% bupivacaine, might induce cauda equina syndrome in older patients.

A 14-year-old girl reported severe pain of the left first toe after a sprain of the left ankle joint when she was 9 years old. She complained of continuous pain in her chest, back, abdomen, and left first toe. The pain at all the sites was of a burning type with intensity of 6 on the numerical rating pain scale. She was unable to walk due to pain. Mechanical allodynia was present. Redness and swelling were recognized over the left first toe. It was concluded that she suffered from Complex Regional Pain Syndrome type I. Initial therapy was started with medications such as nortriptyline, etc. However, they did not work well. Clinical interviews were conducted by a clinical psychologist and a psychiatrist to investigate whether the pain was related to psychogenic factors; they concluded that her pain was mainly related to physical factors rather than psychological ones. It was thought that blockade of inputs from the peripheral nerves would be necessary. We provided an outline of the nerve blocks to the patient and her mother, and obtained their written consent for the procedure. An epidural catheter was inserted at the Th8-9 interspace. 6 mL of 1% lidocaine was injected, which reduced pain and mechanical allodynia. A 0.15% ropivacaine infusion was started at the rate of 6 mL/h for 7 days. This 7-day infusion regime was done twice during 4 weeks. After withdrawal of the epidural catheter, pain relief continued. However, her first left toe pain and mechanical allodynia remained. A nerve block needle was inserted under ultrasound guidance and 10 mL of 0.2% ropivacaine was injected in the peritibial nerve area. A catheter was inserted and 10 mL of 0.2% ropivacaine was injected. A 0.1% ropivacaine infusion was started at the rate of 6 mL/h for 5 days. Her left first toe pain and mechanical allodynia disappeared and she was able to walk. Interestingly, even after withdrawal of the catheter, pain and allodynia did not recur, she was discharged. At 1-year follow-up, the patient was able to attend school.The etiology of the pain spreading with time was believed to be central sensitization. Three patterns of spread of the pain site in CRPS type I patients have been identified: contiguous spread, independent spread, and mirrorimage spread [1]. This patient probably had independent spread.The persistent central sensitization in this patient could have been due to continuous afferent inputs even from normal sensations. Blockade of peripheral nerve input resulted in desensitization of the central nervous system. Reference1 Maleki J, LeBel AA, Bennett GJ, Schwartzman RJ.Patterns of spread in complex regional pain syndrome, type I (reflex sympathetic dystrophy). Pain 2000;88: 259-66.

The present results suggest that complete recovery from midazolam sedation by flumazenil is accompanied by restoration of the attenuated cardiac baroreflex function induced by midazolam.

No abstract