Anaesthesia for thymectomy in myasthenia gravis: a non-muscle-relaxant technique

Laryngeal mask airway without muscle relaxant in femoral head replacement in elderly patients

The number of elderly patients undergoing femoral head replacement surgeries is on the increase. These patients often suffer from comorbidity such as cardiovascular and cerebrovascular complications, which limits the ability of medical teams to employ anesthesia. Thus, alternative methods are required. The aim of this study was to examine the advantage of laryngeal mask airway (LMA) in the absence of muscle relaxant in elderly patients undergoing femoral head replacement operations. Fifty patients (27 males and 23 females) undergoing femoral head replacements were selected for the study between March 2013 and May 2014. The mean value for the age in this group was 74.6±12.5 years. The patients were randomly distributed into two groups of 25. One group was designated as the treatment group and the second group as the control group. For the treatment group, LMA without muscle relaxant was used, and the control group received routine anesthesia. Variations in heart rate (HR), mean arterial pressure (MAP) and oxygen saturation (SPO₂) in the two groups were monitored at different times. Clinical efficacy and muscle relaxation effects were also analyzed. For the treatment group, the HR, MAP and SPO₂ measurements did not reveal any significant variation while these values in the control group demonstrated important dissimilarities. Time to recovery, time to extubation and incidence of throat pain in the treatment group were all markedly decreased as compared to those in control group. The operation time in the treatment group was not significantly different to that of control group. The satisfaction of the muscle relaxation effect in the treatment group was significantly higher than that in the control group while the incidence of adverse reactions was not considerably different. In conclusion, the use of LMA without using muscle relaxant in femoral head replacement surgeries performed on elderly patients showed to be effective and safe.

A standardized protocol for the perioperative management of myasthenia gravis patients. Experience with 110 patients

BACKGROUND

Video-assisted thoracoscopic extended thymectomy (VATET) is well established in the treatment of myasthenia gravis; however, patient selection remains controversial. Perioperative management protocol is lacking, and concerns regarding post-operative myasthenic crisis still remain. We performed a retrospective observational study evaluating the impact of the introduction of a protocol in the perioperative management of patients with myasthenia gravis who underwent VATET.

METHODS

The perioperative management protocol was developed by a team of neurologists and anesthesiologists who reviewed the literature and their previous experience on myasthenia gravis patients. Respiratory, clinical, and neurological patient features were included in the protocol evaluation. A retrospective review of patients who underwent VATET before and after introduction to the protocol was finally performed.

RESULTS

The medical records of 66 patients (pre-protocol group) and 44 patients (protocol group) were available for the study. In the pre-protocol group, 17 patients (26%) were admitted to intensive care unit (ICU) during the post-operative period, while three patients (6.8%) of the protocol group met the criteria for ICU post-operative admission. This resulted in a reduction of 73.5% of patients admitted to ICU (P = 0.023) and in an 80% (P = 0.002) reduction of the use neuromuscular blocking agents. Two post-operative myasthenic crises preceded by bulbar symptoms (1.8%) were identified in the pre-protocol group patients.

CONCLUSIONS

Although the application of our protocol results in a substantial reduction in the recovery of patients in the ICU and in hospital costs, there was no substantial difference in mortality and morbidity between patients admitted to the surgical ward or to ICU.

Anaesthetic considerations in paediatric myasthenia gravis

Myasthenia gravis is of particular interest to anaesthetists because of the muscle groups affected, the pharmacology of the neuromuscular junction, and interaction of both the disease and treatment with many anaesthetic drugs. Anaesthetists may encounter children with myasthenia either to facilitate treatment options or to institute mechanical ventilation in the face of a crisis. This paper reviews the literature pertaining to the pathophysiology and applied pharmacology of the disease and explores the relationship between these and the anaesthetic management. In addition to illustrating the tried-and-tested techniques, some newer management options are explored.

The use of desflurane or propofol in combination with remifentanil in myasthenic patients undergoing a video-assisted thoracoscopic-extended thymectomy

BACKGROUND

Although several studies of the use of desflurane in anesthesia have revealed many desirable qualities, there are no data on the use and effects especially on the neuromuscular function of desflurane on myasthenia gravis (MG) patients. The purpose of this study was to evaluate the use of either desflurane or propofol, both combined with remifentanil, in patients with MG undergoing a video-assisted thoracoscopic-extended thymectomy (VATET).

METHODS

Thirty-six MG patients who underwent VATET were enrolled. Nineteen patients were anesthetized with remifentanil and propofol infused with a target-controlled infusion plasma model, and 17 patients with desflurane and remifentanil. No muscle relaxant was used. The intubating conditions, hemodynamic and respiratory changes, neuromuscular transmission and post-operative complications were evaluated.

RESULTS

Neuromuscular transmission was significantly decreased in the desflurane group (6.7%, from 3% to 9% during anesthesia P=or<0.05). The intubating conditions were good in all 36 patients and 35 patients were successfully extubated in the operating room. The time-to-awakening, post-operatory pH and base excess were significantly different in the two groups, with a decreasing mean arterial pressure in the group administered with desflurane. No patients required reintubation due to myasthenic or cholinergic crisis, or respiratory failure. No other significant differences between the two groups studied were observed.

CONCLUSION

Our experience indicates that anesthesia with desflurane plus remifentanil in patients with MG could determine a reversible muscle relaxation effect, but with no clinical implication, allowing a faster recovery with no difference in extubation time and post-operative complications in the two groups.

Rapid sequence intubation without a neuromuscular blocking agent in a 14-year-old female patient with myasthenia gravis

The anesthesia care of a 14-year-old female patient with an acute exacerbation of myasthenia gravis (MG) and a full stomach who required emergency surgery for placement of a hemodialysis catheter is described. A nonventilated rapid sequence induction was successful with the use of propofol, lidocaine, remifentanil, cricoid pressure and no neuromuscular blocking agent. Although the use of combinations of i.v. anesthetic agents have been suggested for tracheal intubation without the need for neuromuscular blocking agents, none of these techniques has been advocated for rapid sequence intubation. We review existing literature on the topic of tracheal intubation using remifentanil and propofol without a neuromuscular blocking agent and on the topic of tracheal intubation of patients with MG using i.v. anesthesia and no neuromuscular blocking agents.

Experience with programmed steroid treatment with thymectomy in nonthymomatous myasthenia gravis

BACKGROUND

The benefit of thymectomy in myasthenia gravis management is recognized but the perioperative course can fluctuate. The goal of this study was to assess the feasibility and clinical benefit of dose-escalated steroid therapy with thymectomy for nonthymomatous myasthenia gravis.

METHODS

We reviewed the records of 69 myasthenia gravis patients who were followed up after undergoing transsternal thymectomy with extended anterior mediastinal dissection in our hospital between 1976-2000. Forty-eight patients in the programmed treatment group who had dose-escalated and de-escalated steroid therapy during the perioperative period comprised 17 patients with ocular myasthenia gravis and 31 patients with generalized myasthenia gravis. Clinical benefits and clinical remission, which was diagnosed when the patients were symptom-free without medications for at least 1 year, were compared with those of 21 patients in the occasional treatment group who received medications occasionally over the perioperative period.

RESULTS

Postoperative respiratory failure and myasthenic crisis did not occur in the programmed treatment group but did occur in 6 patients in the occasional treatment group. Remission rates in the programmed treatment group (mean follow-up, 6.4 years) were 30% at 3 years, 38% at 5 years, and 46% at 10 years; rates in the occasional treatment group (mean follow-up, 9.6 years) were 25% at 3 years, 25% at 5 years, and 45% at 10 years.

CONCLUSIONS

Programmed steroid therapy in patients with nonthymomatous myasthenia gravis is feasible and it provides clinical benefit when fluctuating symptoms occur during the perioperative period.

Propofol or sevoflurane anesthesia without muscle relaxants allow the early extubation of myasthenic patients

PURPOSE

To compare two non-muscle relaxant anesthetic techniques in myasthenic patients undergoing trans-sternal thymectomy, evaluating the intra- and postoperative conditions including the early extubation in the operating room.

METHODS

Sixty-eight consecutive myasthenic patients undergoing trans-sternal thymectomy were prospectively randomized in two groups: propofol and sevoflurane. In both groups anesthesia was induced with propofol (1-2 mg x kg(-1)) and intubation performed after topical anesthesia of the airway with lidocaine. Anesthesia was maintained in the propofol group (36 patients) with a continuous propofol infusion (3-6 mg x kg(-1) x hr(-1)) and nitrous oxide and, in the sevoflurane group (32 patients), with sevoflurane (end-tidal 1-1.5%) in O2:N2O. Intubating conditions, hemodynamic changes, neuromuscular transmission, postoperative intensive care unit and hospital length of stay and complications were evaluated. Data were analyzed with repeated measure two-way analysis of variance (ANOVA), Chi square test and Student's t test.

RESULTS

Intubating conditions were good in all patients. There were no hemodynamic changes. All patients were extubated in the operating room and none had to be re-intubated for postoperative respiratory depression. Neuromuscular transmission showed minimal changes, more important in the sevoflurane group, and at the end of the procedure the recovery was complete in all patients. We did not observe any other significant differences between the two groups studied.

CONCLUSION

Our data show that these two anesthetic techniques allow the early extubation of myasthenic patients in the operating room.

Paradigm shift in surgical approaches to thymectomy

BACKGROUND

Thymectomy is an established therapy in the management of myasthenia gravis (MG) used in conjunction with medical treatment. The optimal surgical approach to thymectomy, however, has remained controversial.

METHOD

The present review discusses the author's experiences of and the literature regarding the management of MG using the video-assisted thoracic surgery (VATS) approach.

RESULTS

This approach was shown to be technically safe in experienced hands and associated with less postoperative pain, better preservation of lung function in the early postoperative period and better cosmetic results than alternative techniques. The intermediate term results of VATS are comparable to those of more radical approaches. It is hoped that this patient-friendly approach will lead to greater support by patients and their neurologists, for earlier surgery.

CONCLUSION

VATS is an attractive, alternative approach to thymectomy.

Video-assisted thoracoscopic thymectomy for myasthenia gravis

Thymectomy is an established therapy in the management of generalized myasthenia gravis, in addition to medical treatment. However, the optimal surgical approach to thymectomy has remained controversial. There are advocates for transternal, transcervical approaches or "maximal" thymectomy. Video-assisted thoracic surgery (VATS) presents a new approach to thymectomy and forms the basis of this article, in which we discuss patient selection, technique, and results. We believe complete thymectomy, comparable with the transternal approach, could be achieved by VATS. Our intermediate-term results compare well with other surgical techniques. By minimizing chest wall trauma, VATS not only causes less postoperative pain, shortens hospital stay, gives better cosmetic results but also leads to wider acceptance by patients (and their neurologists) for earlier surgery. However, the true role of this approach in thoracic surgery awaits long-term results.

Anesthetic management of a patient with myasthenia gravis during hypothermic cardiopulmonary bypass

The anesthetic management of a patient with myasthenia gravis (MG) who underwent cardiac surgery with hypothermic cardiopulmonary bypass (CPB) is described. Using total intravenous anesthesia with propofol and a moderate dose fentanyl, the variations of neuromuscular function and serum anti-acetylcholine receptor antibody concentration were examined in relation to hypothermic CPB in the absence of muscle relaxants. The anesthetic technique used may have helped to avoid the risks incidental to muscle relaxants in this patient with MG undergoing hypothermic CPB.

Remifentanil and propofol total intravenous anaesthesia for thymectomy in myasthenia gravis

We report a case of trans-sternal thymectomy for myasthenia gravis using a non relaxant, total intravenous technique with propofol and remifentanil. This afforded excellent control of heart rate and pressor responses during surgery while allowing early return of spontaneous ventilation and extubation within nine minutes of termination of anaesthesia. Advantages and disadvantages of this approach versus relaxant and volatile techniques are discussed with particular reference to preservation of neuromuscular function.

Thymectomy for myasthenia gravis

The pathophysiological role of the thymus in myasthenia gravis, and the mechanism of therapeutic effect of thymectomy, are incompletely understood. Nevertheless, thymectomy is a valuable treatment modality in selected patients with generalised myasthenia gravis. There are several types of thymectomy operation, but no one operative approach is clearly superior to the others. Total removal of the thymus gland is essential. Additional excision of associated mediastinal and cervical tissue, that may harbor ectopic thymic rests, is a controversial surgical issue. Surgeons that advocate thymectomy through small, cosmetically favourable, incisions usually believe that simple removal of the thymus gland is an adequate operation. Surgeons that emphasise the importance of removing extrathymic tissue, in addition to the thymus gland, usually favour greater operative exposure through a median sternotomy. To minimise operative morbidity, surgery for myasthenia gravis requires a multidisciplinary (neurology, surgery, anaesthesia) approach to peri-operative care.