Estimation of the success rate of anesthetic management for thymectomy in patients with myasthenia gravis treated without muscle relaxants: a retrospective observational cohort study

Abstract

Although maintaining anesthesia for myasthenia gravis (MG) with minimal muscle relaxants (MR) is common, the success rate of anesthetic management for MG without MR is not clear. We therefore retrospectively examined the success rate of anesthetic management for MG without MR among 66 consecutive cases of thymectomy for MG performed at our hospital between January 2004 and April 2010, before approval of using sugammadex. A total of 60 patients (90.9 %) were treated without MR (N group). Among the 60 cases, 17 (28.3 %) patients were not extubated in the operating room due to postoperative respiratory depression or other reasons. Therefore, the success rate of anesthetic management for thymectomy in patients with MG without treating MR was 71.7 % (43/60) [95 % confident interval (CI): 65.9-77.5 %]. The reasons for using MR included coughing at intubation in one case, bucking during surgery in two cases, and MR was considered to be safer by the attending anesthesiologist in three cases. The number of cases of impossible extubation requiring ventilation on that day was three in the N group and none in the R group. Finally, the success rate of anesthetic management for MG without MR was estimated to be 71.1 % (95 % CI: 65.9-77.5 %).

Magnesium sulfate reduces rocuronium dose needed for satisfactory double lumen tube placement condition in patients with myasthenia gravis

“…Very small dose of NMB and residual neuromuscular blockade effect may result in respiratory distress or loss of airway protection during emergence from anesthesia. As a result, some anaesthetists prefer to avoid NMB, whereas intubation without NMBs was reported increasing the risk of difficult tracheal intubation and intubation-related complications [4,5].…”

“…Patients with MG are highly sensitive to nondepolarizing neuromuscular blockers [3]. The use of neuromuscular blocker (NMB) in these patients is always difficult and controversial because its use is associated with an increase risk of failed extubation and postoperative respiratory failure [3,4]. However, perioperative stress may also lead to exacerbation of MG and postoperative respiratory failure [4][5][6].…”

Magnesium sulfate reduces the rocuronium dose needed for satisfactory double lumen tube placement conditions in patients with myasthenia gravis

“…A very small dose of NMB and residual neuromuscular blockade effect may result in respiratory distress or loss of airway protection during emergence from anaesthesia. As a result, some anaesthetists prefer to avoid NMB, whereas intubation without NMBs was reported to increase the risk of difficult tracheal intubation and intubation-related complications [4,5].…”

“…Patients with MG are highly sensitive to nondepolarizing neuromuscular blockers [3]. The use of neuromuscular blocker (NMB) in these patients is always controversial because its use is associated with increased risk of failed extubation and postoperative respiratory failure [3,4]. Moreover, perioperative stress may also lead to exacerbation of MG and postoperative respiratory failure [4][5][6].…”

Magnesium sulfate decreases the dose of rocuronium for satisfactory double lumen tube placement condition in patients with myasthenia gravis

“…When performing general anesthesia for these patients, neuromuscular blocker (NMB) administration is always a controversial issue [3,4]. The use of NMB in MG patients may increase the risk of unsuccessful extubation and postoperative respiratory failure, what's more, in some circumstances, perioperative stress induced exacerbation of MG makes these risks more complicated [4][5][6]; while the strategy of no NMB may result in unsatisfactory intubation condition and increase the incidence of upper airway injury [7]. In my institution, we routinely titrate small doses of non-depolarizing NMB till Train of Four (TOF), the neuromuscular monitoring parameter, is less than 10% before intubation in MG patients.…”