Study: Post-op weakness mitigated by use of acceleromyography device
Intraoperative muscle monitoring by use of an acceleromyograph may preserve muscle strength and improve quality of recovery better than conventional monitoring methods, according to a study published in the November issue of Anesthesiology.
An acceleromyograph uses a miniature piezoelectric transducer to measure the accelerated activity of stimulated muscle tissue. Acceleromyography is useful in surgeries that require induced paralysis for optimal operating conditions.
Glenn S. Murphy, MD, and colleagues of the anesthesiology department at Evanston Hospital in Evanston, Ill., monitored 155 patients who were randomized to receive intraoperative acceleromyography—the test group—or conventional train-of-four monitoring—the control group. Upon a patient’s arrival to the postanesthesia care unit (PACU), their train-of-four ratios were measured using acceleromyography and they were assessed for 16 symptoms and 11 signs of residual paresis. This was repeated 20, 40 and 60 minutes after PACU admission, according to the authors.
"We hypothesized that acceleromyography monitoring, by reducing the incidence of postoperative residual blockage, would diminish overall weakness and associated symptoms and signs of residual paresis,” wrote Murphy et al. “Early recovery during PACU stay was assessed and quantified using a standardized examination for symptoms and signs of muscle weakness, quality of recovery scoring systems and standard recovery landmarks.”
The 155 patients were administered intravenous midazolam and later induced with anesthesia. Muscular activity was assessed in both the control and test groups. “To ensure a uniform and consistent evaluation of all subjects, testing was performed by a single research assistant and all evaluations for signs and symptoms of muscle weakness were performed in a standardized order,” the authors wrote. Tests included head lifts, hand grips and eye opening, among several others.
Residual blockage was reduced in the test group by 35.5 percent and they experienced less overall weakness, according to Murphy et al. Patients in the acceleromyography group exhibited less overall weakness, number of symptoms and number of signs at each test interval.
“Our findings demonstrate that unpleasant symptoms of muscle weakness are reduced and patient satisfaction is improved when quantitative acceleromyography monitoring is used in the operating room. However, PACU length of stay was unaffected by the type of neuromuscular monitoring used intraoperatively,” the authors concluded. “The relationship between residual neuromuscular blockade and symptoms of muscle weakness, overall quality of recovery and PACU length of stay may be further defined in future studies using other, more effective neuromuscular reversal agents, such as suggamadex.”
An acceleromyograph uses a miniature piezoelectric transducer to measure the accelerated activity of stimulated muscle tissue. Acceleromyography is useful in surgeries that require induced paralysis for optimal operating conditions.
Glenn S. Murphy, MD, and colleagues of the anesthesiology department at Evanston Hospital in Evanston, Ill., monitored 155 patients who were randomized to receive intraoperative acceleromyography—the test group—or conventional train-of-four monitoring—the control group. Upon a patient’s arrival to the postanesthesia care unit (PACU), their train-of-four ratios were measured using acceleromyography and they were assessed for 16 symptoms and 11 signs of residual paresis. This was repeated 20, 40 and 60 minutes after PACU admission, according to the authors.
"We hypothesized that acceleromyography monitoring, by reducing the incidence of postoperative residual blockage, would diminish overall weakness and associated symptoms and signs of residual paresis,” wrote Murphy et al. “Early recovery during PACU stay was assessed and quantified using a standardized examination for symptoms and signs of muscle weakness, quality of recovery scoring systems and standard recovery landmarks.”
The 155 patients were administered intravenous midazolam and later induced with anesthesia. Muscular activity was assessed in both the control and test groups. “To ensure a uniform and consistent evaluation of all subjects, testing was performed by a single research assistant and all evaluations for signs and symptoms of muscle weakness were performed in a standardized order,” the authors wrote. Tests included head lifts, hand grips and eye opening, among several others.
Residual blockage was reduced in the test group by 35.5 percent and they experienced less overall weakness, according to Murphy et al. Patients in the acceleromyography group exhibited less overall weakness, number of symptoms and number of signs at each test interval.
“Our findings demonstrate that unpleasant symptoms of muscle weakness are reduced and patient satisfaction is improved when quantitative acceleromyography monitoring is used in the operating room. However, PACU length of stay was unaffected by the type of neuromuscular monitoring used intraoperatively,” the authors concluded. “The relationship between residual neuromuscular blockade and symptoms of muscle weakness, overall quality of recovery and PACU length of stay may be further defined in future studies using other, more effective neuromuscular reversal agents, such as suggamadex.”