Preoperative Low-Dose Steroid Can Prevent Respiratory Insufficiency After Thymectomy in Generalized Myasthenia Gravis

Abstract

Background: Postoperative respiratory insufficiency (PRI) in myasthenia gravis (MG) often occurs within several days after thymectomy and remains problematic. In limited studies reporting that preoperative steroids prevented PRI in patients with MG, high doses of steroids were used and detailed information on the use of steroids is limited. Because high-dose steroids significantly increase the risk of adverse effects, we studied 37 patients with generalized MG to investigate whether low-dose steroids might prevent PRI. Methods: The low-dose steroids were started orally, and the dose was gradually increased to the maximum level (30 mg/day). Immediately before thymectomy, patients received the maximum dose of oral steroids daily. PRI was defined as the development of restrictive dysfunction requiring mechanical ventilation within 3 days after thymectomy and total postoperative mechanical ventilation support time of >24 h. Results: The rate of PRI in the low-dose steroid use group was significantly lower than that in the no-steroid use group. The postoperative stay in the intensive care unit was shorter in the steroid use group. Conclusions: Extended thymectomy is a well-accepted surgical treatment for selected patients with MG. However, PRI remains problematic. Our results suggest that not only preoperative high-dose steroid treatment, but also low-dose steroid treatment can prevent PRI.

Supplemental Factors Including Those Associated with Anesthesiology for Respiratory Insufficiency after Thymectomy in Generalized Myasthenia Gravis

“…We respond to five suggestions from the viewpoint of anesthesiologists regarding our article [1]. In 12 patients with myasthenia gravis (MG) who preoperatively received steroids (17.8 ± 3.1 mg/day), the steroid dose was decreased to 6.7 ± 4.6 mg/day (dose reduction, 11.5 ± 4.7 mg/day) at final follow-up (32.2 ± 17.3 months), and 4 other patients received both steroids (20, 7, 5, and 10 mg/day) and immunosuppressants.…”

“…In 12 patients with myasthenia gravis (MG) who preoperatively received steroids (17.8 ± 3.1 mg/day), the steroid dose was decreased to 6.7 ± 4.6 mg/day (dose reduction, 11.5 ± 4.7 mg/day) at final follow-up (32.2 ± 17.3 months), and 4 other patients received both steroids (20, 7, 5, and 10 mg/day) and immunosuppressants. The decrease in the steroid dose might be attributed to significant reductions in postoperative serum antibodies binding to acetylcholine receptor (AchR-Ab) after both preoperative steroid use and thymectomy [1], thereby stabilizing the clinical status of MG. We used the term ‘low-dose steroids' in the title because the dose was lower than that used in previous studies, but we consider the dosage of steroids in our study to be physiological and not low. As pointed out, the surgical technique, preoperative use of acetylcholinesterase, and preoperative respiratory function tests can have an impact on preoperative respiratory insufficiency (PRI).…”

“…As pointed out, the surgical technique, preoperative use of acetylcholinesterase, and preoperative respiratory function tests can have an impact on preoperative respiratory insufficiency (PRI). With regard to the surgical technique, the number of surgeons differed between the steroid use group (one surgeon) and the steroid nonuse group (four surgeons) [1]. The preoperative use of acetylcholinesterase, which can induce respiratory insufficiency [2], which was slightly but not significantly higher in the steroid nonuse group (80%) than in the steroid use group (62%).…”

Low-Dose Steroid after Thymectomy in Myasthenia Gravis: Is It a Complete Solution for Postoperative Respiratory Insufficiency?

“…Second, surgical technique is an important aspect that needs consideration, because it does not have the same effect on all the patients [3]. This may result in complex pathways, as steroid requirement can differ with different surgery techniques, resulting in the impairment of the standardization and influence rate of postoperative insufficiency.…”

“…We believe two points need explanation: (a) More detailed information should be given about the anesthetic technique used, narcotics and neuromuscular blocking agents and their doses. Also the neuromuscular monitorization should be described [3]. (b) In the result section, it is stated that the use of epidural anesthesia did not differ in both groups, whereas the use of epidural anesthesia is not mentioned in the methods section [5].…”