Perioperative medical management and outcome following thymectomy for myasthenia gravis

Purpose: To describe the evolution of the perioperative management of myasthenia gravis (MG) patients undergoing thymectomy and to question the need for systematic postoperative ventilation. Clinical features: We collected data retrospectively from 36 consecutive MG patients who underwent thymectomy over a 21-yr period, via transthoracic, -cervical or -sternal incisions (n = 5, n = 7, n = 24, respectively). From 1980 to 1993, a balanced anesthetic technique (n = 24) included various inhalational agents with opiates and myorelaxants tin eight cases); 22 patients were admitted to the intensive care unit (ICU), Since 1994, iv propofol was combined with epidural bupivacaine and sufentanil (n = 12); all patients were admitted to the postanesthesia care unit, Short-term postoperative ventilation (median time four hours, range from three to 48 hr) was required in eight patients who had longer hospital stay (median stay = 12 days, range (8-28) vs five days (4-15) for patients with early extubation, P <0.05) but similar clinical improvement six months after thymectomy. Postoperative ventilatory support was required more frequently when a balanced anesthetic technique was used (odds ratio = 4.2 (1.1-9.7), P = 0.03) and particularly when myorelaxants were given (odds ratio = 13.9 (2.1-89.8), P = 0.009). Leventhal's scoring system had low sensitivity (22.2%) and positive predictive values (25%). Conclusions: Our data show that the severity of MG failed to predict the need for postoperative ventilation. A combined anesthetic technique was a safe and cost-effective alternative to balanced anesthesia as it provided optimal operating conditions and resulted in fewer admissions in ICU and shorter hospital stays.