Relationship between cardiac output and onset of succinylcholine chloride action in electroconvulsive therapy patients

Influence of hemodynamic variations on the pharmacokinetics of landiolol in patients undergoing cardiovascular surgery

Although landiolol is useful in the emergency management of atrial fibrillation, atrial flutter, and tachycardia, as well as in perioperative arrhythmia control, the influence of hemodynamic changes on the pharmacokinetics of landiolol is unknown. We investigated the influence of hemodynamic variation and the following hepatocirculatory changes after systemic heparinization on the pharmacokinetics of landiolol in patients undergoing cardiovascular surgery under cardiopulmonary bypass. Cardiac output and cardiac index (CI) were continuously monitored in 19 patients using an arterial pressure-based cardiac output monitor. The middle and right hepatic venous blood flow indexes (mHVBFI and rHVBFI) were measured by transesophageal echocardiography, and hemodynamic data were collected at points (T1-T3) as follows: T1, before administration of heparin and after sternotomy; T2, just before systemic heparinization (300 U/kg); T3, 10 min after T2. The plasma concentration of landiolol was measured by HPLC at the same point. After administration of heparin, mean arterial blood pressure, CI, mHVBFI, and rHVBFI were significantly decreased (<0.05). Heart rate was not significantly changed. After systemic heparinization, the landiolol concentration was significantly decreased from 0.407±0.251 µg·mL(-1) to 0.232±0.207 µg·mL(-1) (<0.01). There was no significant difference between T1 and T2 (=0.88). In conclusion, the plasma concentration of landiolol was decreased by diminished CI due to systemic heparinization, but not affected by the change of hepatic blood flow.

Comparison of recovery times from rocuronium-induced muscle relaxation after reversal with three different doses of sugammadex and succinylcholine during electroconvulsive therapy

PURPOSE

This study was conducted to compare recovery times from rocuronium-induced muscle relaxation after reversal with three different doses of sugammadex with succinylcholine during electroconvulsive therapy (ECT).

METHODS

Seventeen patients who were scheduled to undergo ECT were studied. Anesthesia was induced by use of propofol (1.0 mg/kg) followed by either succinylcholine (SCC) (1 mg/kg) or rocuronium (0.6 mg/kg). Assisted mask ventilation was initiated with 100% oxygen. After T1 was assessed as being zero by neuromuscular monitoring, an electroshock stimulus was applied bilaterally. Patients receiving rocuronium were infused with 16, 8, or 4 mg/kg sugammadex immediately after the seizure stopped to reverse the muscle relaxation. Neuromuscular monitoring was continued until recovery of the train-of-four ratio to 0.9 at the tibial nerve in the leg. The times to recovery of T1 to 10 and 90% with both relaxants were compared.

RESULTS

The time to recovery of T1 to 90% after 16 mg/kg sugammadex was shorter than that in subjects treated with SCC (p = 0.046), whereas that after 4 mg/kg sugammadex was longer than that in subjects treated with SCC (SCC group: 429 ± 65 s, 16 mg/kg sugammadex group: 387 ± 63 s*, 8 mg/kg sugammadex group: 462 ± 66 s, 4 mg/kg sugammadex group: 563 ± 45 s(*,#); *p < 0.05 compared with SCC, (#)p < 0.01 compared with 16 mg/kg sugammadex).

CONCLUSIONS

This study demonstrates the efficacy of rocuronium-sugammadex as an alternative to SCC for muscle relaxation during ECT, and indicates that 8 mg/kg sugammadex produces equally rapid recovery from rocuronium muscular relaxation compared with spontaneous recovery from 1 mg/kg SCC during ECT.