Minimum Effective Doses of Succinylcholine and Rocuronium During Electroconvulsive Therapy: A Prospective, Randomized, Crossover Trial.

BACKGROUND: Neuromuscular blockade is required to control excessive muscle contractions during electroconvulsive therapy (ECT). In a crossover, assessor-blinded, prospective randomized study, we studied the minimum effective dose (MED) of succinylcholine and rocuronium for ECT. The MED was the lowest dose to provide a predefined qualitative measure of acceptable control of muscle strength during induced convulsions. METHODS: Succinylcholine (0.8 mg kg) or rocuronium (0.4 mg kg) was randomly administered in 227 ECT sessions to 45 patients. The dose was incrementally increased or decreased by 10% based on 2 psychiatrists' (blinded to treatment) assessment of "acceptable" or "not acceptable" control of evoked muscle contractions (sufficient versus insufficient or excessive paralysis). The neuromuscular transmission was monitored quantitatively until full recovery. RESULTS: In our study, the MEDs of succinylcholine and rocuronium to produce acceptable ECT conditions in 50% of patients (MED50ECT) were 0.85 mg kg (95% confidence interval [CI], 0.77-0.94) and 0.41 mg kg (95% CI, 0.36-0.46) and in 90% of patients (MED90ECT) were 1.06 mg kg (95% CI, 1.0-1.27) and 0.57 mg kg (95% CI, 0.5-0.6), respectively. Nadir twitch height for acceptable muscle activity was 0% (0-4) and 4% (0-30; P < 0.001), respectively, and the time to recovery of the neuromuscular transmission was 9.7 ± 3.5 and 19.5 ± 5.7 minutes, respectively. CONCLUSIONS: A twitch suppression of >90% is needed for control of motor contractions during ECT. The initial ECT dose of succinylcholine should be selected based on each patient's preprocedural condition, ranging between 0.77 and 1.27 mg kg to produce acceptable muscle blockade in 50% to 90% of patients. Rocuronium-neostigmine combination is a safe alternative if appropriately dosed (0.36-0.6 mg kg) and monitored.

Effects of neostigmine reversal of nondepolarizing neuromuscular blocking agents on postoperative respiratory outcomes: a prospective study.

BACKGROUND: We tested the hypothesis that neostigmine reversal of neuromuscular blockade reduced the incidence of signs and symptoms of postoperative respiratory failure. METHODS: We enrolled 3,000 patients in this prospective, observer-blinded, observational study. We documented the intraoperative use of neuromuscular blocking agents and neostigmine. At postanesthesia care unit admission, we measured train-of-four ratio and documented the ratio of peripheral oxygen saturation to fraction of inspired oxygen (S/F). The primary outcome was oxygenation at postanesthesia care unit admission (S/F). Secondary outcomes included the incidence of postoperative atelectasis and postoperative hospital length of stay. Post hoc, we defined high-dose neostigmine as more than 60 µg/kg and unwarranted use of neostigmine as neostigmine administration in the absence of appropriate neuromuscular transmission monitoring. RESULTS: Neostigmine reversal did not improve S/F at postanesthesia care unit admission (164 [95% CI, 162 to 164] vs. 164 [161 to 164]) and was associated with an increased incidence of atelectasis (8.8% vs. 4.5%; odds ratio, 1.67 [1.07 to 2.59]). High-dose neostigmine was associated with longer time to postanesthesia care unit discharge readiness (176 min [165 to 188] vs. 157 min [153 to 160]) and longer postoperative hospital length of stay (2.9 days [2.7 to 3.2] vs. 2.8 days [2.8 to 2.9]). Unwarranted use of neostigmine (n = 492) was an independent predictor of pulmonary edema (odds ratio, 1.91 [1.21 to 3.00]) and reintubation (odds ratio, 3.68 [1.10 to 12.4]). CONCLUSIONS: Neostigmine reversal did not affect oxygenation but was associated with increased atelectasis. High-dose neostigmine or unwarranted use of neostigmine may translate to increased postoperative respiratory morbidity.

Routine repeat head CT for minimal head injury is unnecessary.

BACKGROUND: Patients with MHI and a positive head computed tomography (CT) scan frequently have a routine repeat head CT (RRHCT) to identify possible evolution of the head injury requiring intervention. RRHCT is ordered based on the premise that significant injury progression may take place in the absence of clinical deterioration. METHODS: In a Level I urban trauma center with a policy of RRHCT, we reviewed the records of 692 consecutive trauma patients with Glasgow Coma Scale scores of 13-15 and a head CT (October 2004 through October 2005). The need for medical or surgical neurologic intervention after RRHCT was recorded. Patients with a worse and unchanged RRHCT were compared, and independent predictors of a worse RRHCT were identified by stepwise logistic regression. RESULTS: There were 179 patients with MHI and RRHCT ordered. Of them, 37 (21%) showed signs of injury evolution on RRHCT and 7 (4%) required intervention. All 7 had clinical deterioration preceding RRHCT. In no patient without clinical deterioration did RRHCT prompt a change in management. A Glasgow Coma Scale score less than 15 (13 or 14), age higher than 65 years, multiple traumatic lesions found on first head CT, and interval shorter than 90 minutes from arrival to first head CT predicted independently a worse RRHCT. CONCLUSIONS: RRHCT is unnecessary in patients with MHI. Clinical examination identifies accurately the few who will show significant evolution and require intervention.