The sudden hemodynamic disturbance in the perioperative period can occur because of various surgical and anesthetic reasons but hemodynamic collapse due to noxious stimulus of periosteum stripping has not been described. We report two cases of severe hypotension and bradycardia during periosteum stripping in orthopedic surgery under subarachnoid block even though the block level was adequate. In our patients, hemodynamic collapse occurred specifically at a moment when surgeons manipulated periosteum and fall in blood pressure and heart rate was sudden in onset. The hemodynamic disturbance did not appear to be related to vagally mediated or due to blockade of sympathetic fibers but appeared to be related to periosteal nociceptors.
Adrenergic Fibers ; Anesthesia, Spinal ; Blood Pressure ; Bradycardia ; Heart Rate ; Hemodynamics ; Humans ; Hypotension ; Nociceptors ; Orthopedics ; Perioperative Period ; Periosteum

BACKGROUND: Etomidate injection is often associated with myoclonus. Etomidate injection technique influences the incidence of myoclonus. This study was designed to clarify which of the two injection techniques—slow injection or priming with etomidate—is more effective in reducing myoclonus. METHODS: This prospective randomized controlled study was conducted on 189 surgical patients allocated to three study groups. Control group (Group C, n = 63) received 0.3 mg/kg etomidate (induction dose) over 20 s. Priming group (Group P, n = 63) received pretreatment with 0.03 mg/kg etomidate, followed after 1 min by an etomidate induction dose over 20 s. Slow injection group (Group S, n = 63) received etomidate (2 mg/ml) induction dose over 2 min. The patients were observed for occurrence and severity of myoclonus for 3 min from the start of injection of the induction dose. RESULTS: The incidence of myoclonus in Group P (38/63 [60.3%], 95% CI: 48.0–71.5) was significantly lower than in Group C (53/63 [84.1%], 95% CI: 72.9–91.3, P = 0.003) and Group S (49/63 [77.8%], 95% CI: 66.0–86.4, P = 0.034). Myoclonus of moderate or severe grade occurred in significantly more patients in Group C (68.3%) than in Group P (36.5%, P < 0.001) and Group S (50.8%, P = 0.046), but the difference between Groups P and S was not significant (P = 0.106). CONCLUSIONS: Priming is more effective than slow injection in reducing the incidence of myoclonus, but their effects on the severity of myoclonus are comparable.
Etomidate ; Humans ; Incidence ; Myoclonus* ; Prospective Studies