Use of protocol and evaluation of postoperative residual curarization incidence in the absence of intraoperative acceleromyography - Randomized clinical trial / Aplicação de protocolo e avaliação da incidência de curarização residual pós-operatória na ausência de aceleromiografia intraoperatória - Ensaio clínico randomizado

Abstract Objective Evaluate the incidence of postoperative residual curarization (PORC) in the post-anesthesia care unit (PACU) after the use of protocol and absence of intraoperative acceleromyography (AMG). Methods Randomized clinical trial with 122 patients allocated into two groups (protocol and control). Protocol group received initial and additional doses of rocuronium (0.6 mg·kg-1 and 10 mg, respectively); the use of rocuronium was avoided in the final 45 min; blockade reversal with neostigmine (50 µg·kg-1); time ≥15 min between reversion and extubation. Control: initial and additional doses of rocuronium, blockade reversal, neostigmine dose, and extubation time, all at the discretion of the anesthesiologist. AMG was used in the PACU and PORC considered at T4/T1 ratio <1.0. Results The incidence of PORC was lower in protocol group than in control group (25% vs. 45.2%, p = 0.02). In control group, total dose of rocuronium was higher in patients with PORC than without PORC (0.43 vs. 0.35 mg·kg-1·h-1, p = 0.03) and the time interval between the last administration of rocuronium and neostigmine was lower (75.0 vs. 101.0 min, p < 0.01). In protocol group, there was no difference regarding the analyzed parameters (with PORC vs. without PORC). Considering the entire study population and the presence or absence of PORC, total dose of rocuronium was higher in patients with PORC (0.42 vs. 0.31 mg·kg-1·h-1, p = 0.01), while the time interval between the last administration of rocuronium and neostigmine was lower (72.5 vs. 99.0 min, p ≤ 0.01). Conclusion The proposed systematization reduced PORC incidence in PACU in the absence of intraoperative AMG.

Resumo Objetivo Avaliou-se a incidência de curarização residual pós-operatória (CRPO) na sala de recuperação pós-anestésica (SRPA) após emprego de protocolo e ausência de aceleromiografia (AMG) intraoperatória. Métodos Ensaio clínico, aleatório, com 122 pacientes, distribuídas em dois grupos: protocolo e controle. Protocolo: dose inicial e adicionais de rocurônio foram de 0,6 mg.kg-1 e 10 mg, respectivamente; evitou-se o uso de rocurônio nos 45 minutos finais; reversão do bloqueio com neostigmina (50 µg.kg-1); tempo ≥ 15 minutos entre reversão e extubação. Controle: doses inicial e adicional de rocurônio, reversão do bloqueio, dose de neostigmina e momento da extubação decididos pelo anestesiologista. Foi usada AMG na SRPA e considerado CRPO razão T4/T1 < 1,0. Resultados A incidência de CRPO foi menor no grupo protocolo em relação ao controle (25% vs. 45,2%; p = 0,02). No grupo controle, a dose total de rocurônio foi maior em pacientes com CRPO em relação àqueles sem CRPO (0,43 vs. 0,35 mg.kg-1.h-1; p = 0,03) e o intervalo entre a última administração de rocurônio e a neostigmina foi menor (75,0 vs. 101,0 min; p < 0,01). No grupo protocolo não houve diferença dos parâmetros analisados (com CRPO vs. sem CRPO). Considerando toda a população de estudo e a presença ou não de CRPO, a dose total de rocurônio foi maior em pacientes com CRPO (0,42 vs. 0,31 mg.kg-1.h-1; p = 0,01), enquanto o intervalo entre a última administração de rocurônio e a neostigmina foi menor (72,5 vs. 99,0 min; p ≤ 0,01). Conclusão A sistematização proposta reduziu a incidência de CRPO na SRPA na ausência de AMG intraoperatória.

What anesthesiologists ask to know and should know about the neuromuscular monitoring: an updated review

The increase in mortality and morbidity associated with the use of muscle relaxants, is associated with a lack of clinical pharmacological knowledge of the drugs, and a lack of understanding the risk of postoperative residual curarization. This is due to the absence of standards for neuromuscular monitoring. Clinicians experienced in neuromuscular monitoring and using muscle relaxants in the clinic may have some queries regarding the monitoring: Why should neuromuscular monitoring be done? Are clinical tests really not effective? Why is it not good when I actually perform neuromuscular monitoring? Would using sugammadex not require neuromuscular monitoring? This review answers most of the questions that many clinicians have, and also forwards the knowledge required of clinicians.

Comparison of clinical validation of acceleromyography and electromyography in children who were administered rocuronium during general anesthesia: a prospective double-blinded randomized study / 대한마취과학회지

BACKGROUND: Electromyography and acceleromyography are common neuromuscular monitoring devices. However, questions still remain regarding the use of acceleromyography in children. This study compared the calibration success rates and intubation conditions in children after obtaining the maximal blockade depending on each of the devices METHODS: Children, 3 to 6 years old, were randomly allocated to the TOF-Watch SX acceleromyography group or the NMT electromyography group. The induction was performed with propofol, fentanyl, and rocuronium. The bispectral index and 1 Hz single twitch were monitored during observation. The calibration of the each device was begun when the BIS dropped to 60. After successful calibration, rocuronium 0.6 mg/kg was injected. A tracheal intubation was performed when the twitch height suppressed to 0. The rocuronium onset time (time from administration to the maximal depression of twitch height) and intubating conditions were rated in a blinded manner. RESULTS: There was no difference in the calibration success rates between the two groups; and the calibration time in the electromyography group (16.7 +/- 11.0 seconds) was shorter than the acceleromyography group (28.1 +/- 13.4 seconds, P = 0.012). The rocuronium onset time of the electromyography group (73.6 +/- 18.9 seconds) was longer than the acceleromyography group (63.9 +/- 18.8 seconds, P = 0.042) and the intubation condition of the electromyography group (2.27 +/- 0.65) was better than the acceleromyography group (1.86 +/- 0.50, P = 0.007). CONCLUSIONS: Electromyography offers a better compromise than acceleromyography with respect to the duration of calibration process and surrogate for the optimal time of tracheal intubation in children.

The Neuromuscular Pharmacodynamics for Rocuronium at the Adductor Pollicis and the Flexor Hallucis Brevis Muscle / 대한마취과학회지

BACKGROUND: Neuromuscular block is commonly monitored using the adductor pollicis (AP) because of its easy access. However, the hand may not always be accessible for neuromuscular monitoring during surgery. In that situation, monitoring of the flexor hallucis brevis (FHB) secondary to stimulation of the tibial nerve at the ankle joint may be used as an alternative. METHODS: During propofol and remifentanil anesthesia, acceleromyography of the thumb and big toe were recorded. Single twitch responses were measured simultaneously after cumulative administration of rocuronium from 80 to 200microgram/kg at intervals of 40microgram/kg. Furthermore, the amount of rocuronium required for 50% and 95% twitch height depression were calculated. Rocuronium was infused continuously to maintain 5% to 15% twitch responses. We also obtained the onset, duration of action, and antagonism effect of neostigmine from both muscles via neostigmine (20microgram/kg) administration. RESULTS: ED50 and ED95 were significantly lower in the AP than in the FHB. The highest twitch response at peak and neostigmine antagonism were significantly higher in the FHB than in the AP. However, there was no significant difference in the onset time or duration of neostigmine between AP and FHB. CONCLUSIONS: Due to its resistance to rocuronium, the onset of FHB is not a good indicator of optimal conditions for tracheal intubation. Also, because of its higher antagonism effect, there is potential risk of overlooking a residual block. Sufficient recovery of the block should be readjusted to estimate recovery in the FHB with the use of other reliable clinical tests.

Effective Dose of Atracurium in Korean Adults / 대한마취과학회지

BACKGROUND: Atracurium is non-depolarizing neuromuscular blocking agent with intermediate duration of action. The purpose of this study is to determine the effective dose (ED) of atracurium in Korean adults. METHODS: We studied 100 patients, aged 18-59 yr, who had given informed consent and belonged to class I or II of ASA physical status. We excluded patients who had cardiac, pulmonary, renal, hepatic, neurological, psychiatric, muscular, inflammatory or endocrine disease, as were pregnant women and patient with recent exposure (< 72 hr) to medications known to interfere with neuromuscular transmission. In all patients, anesthesia was induced with intravenous propofol 2 mg/kg and fentanyl 2microgram/kg. Anesthesia was maintained with continous infusion of propofol 5 mg/kg and 100% oxygen through mask, supplemented with fentanyl as required. The electrodes were applied over the ulnar nerve at the wrist. Then, the patients were stimulated with a 50 Hz supramaximal tetanic stimulation for 4 seconds and a 1 Hz single twitch for 5 minutes to stablize muscle contraction and then a control value was obtained with acceleromyography (TOF-Guard(R), Organon Technika BV , Netherland). Thereafter, a 0.1 Hz single twitch of adductor pollicis was kept during the study. The 100 patients were randomly divided to five groups. The patients in each group received 90microgram/kg, 120microgram/kg, 150microgram/kg, 180microgram/kg, 210microgram/kg of atracurium. We measured the maximal response (% reduction) and time to achieve maximal blockade of single twitch. Values were expressed as mean +/- SD or 95% confidence intervals. ED values were obtained from the regression analysis using probit model. A P value of < 0.05 was considered statistically significant. RESULTS: There were no significant defferences in age, body mass index and temperature among dose groups. ED50 and ED95 of atracurium were 128microgram/kg, 236microgram/kg, respectively. For men, ED50 and ED95 were 127microgram/kg, 249microgram/kg, respectively. For women, ED50 and ED95 were 128microgram/kg, 236microgram/kg, respectively. The onset time to maximum blockade was reduced as dose was increased. CONCLUSIONS: ED50 and ED95 of atracurium in Korean adults were 128microgram/kg, 236microgram/kg, respectively. There was no difference between the effective doses of men and women. Onset time of atracurium was reduced as doses were increased.

Effective Dose of Rocuronium in Koreans / 대한마취과학회지

BACKGROUND: Currently no information is available about the effective dose (ED) of rocuronium in Koreans. The purpose of this study was to determine the ED of rocuronium in a Korean cohort. METHODS: We studied one hundred and twenty patients with a class I or II ASA physical status. Anesthesia was induced with propofol 2 mg/kg and fentanyl 2microgram/kg intravenously, and maintained by the continuous infusion of propofol 5 mg/kg/h and 100% oxygen by mask ventilation. Additional increments of fentanyl 50microgram were given as required, and surface electrodes were applied over the ulnar nerve at the wrist. Before each dose of rocuronium was administered intravenously, all patients were stimulated with a 50 Hz supramaximal tetanic stimulation for 5 seconds followed by a 1 Hz single twitch stimulation for 5 minutes to stabilize muscle contraction. The control value was then calibrated by acceleromyography. Twenty female patients were cumulatively administered rocuronium, at an initial dose of 100microgram/kg followed by doses incremented by 50microgram/kg. And 100 patients were allocated to five single dose groups. Subjects these dose groups were randomly administered 100microgram/kg, 150microgram/kg, 200microgram/kg, 250microgram/ kg, or 300microgram/kg of rocuronium. We recorded both the 0.1 Hz single twitch responses of the adductor pollicis and the onset times to maximal blockade. The effect of rocuronium on single twitch was calculated as % reduction versus the control. Results were expressed as means +/- SD or as 95% confidence intervals. A P value of <0.05 was considered statistically significant. EDs were estimated by linear regression analysis using a probit model. RESULTS: No significant differences were found in age, weight, height, or temperature among the dose groups. ED50 and ED95 were determined to be 184microgram/kg and 382microgram/kg, respectively. For men, ED50 and ED95 were 188microgram/kg, 386microgram/kg and for women, 180microgram /kg, 376microgram/kg, respectively. The ED50 and ED95 as determined by the cumulative method in women were 212microgram/kg, 445microgram/kg, respectively. As the dose of rocuronium increased, onset times decreased. Mean onset time was 178 sec. CONCLUSIONS: The mean ED95 of rocuronium in Koreans was determined to be 382microgram /kg, and the ED of women was lower than that of men. The dose-response curve of the cumulative method was positioned to the right of that of the single bolus method in women. The onset time to maximum blockade reduced as the dose was increased.