Predictors of extubation outcomes following myasthenic crisis

Ultrasonographic Assessment of Diaphragm Function to Predict Need for Mechanical Ventilation and its Liberation in Patients with Neuromuscular Disorders: An Observational Cohort Pilot Study

BACKGROUND

Management of assisted ventilation and determining the optimal timing for discontinuation presents a significant clinical obstacle in patients affected by neuromuscular (NM) diseases. This study aimed to evaluate the efficacy of ultrasound in appraising diaphragmatic function for predicting the necessity of intubation and determining the opportune moment to discontinue mechanical ventilation (MV) in patients with NM disorders.

METHODS

The study was conducted in adult patients with NM diseases requiring inpatient care in the high-dependency neurology ward and the intensive care unit. Ultrasonographic assessment of diaphragmatic excursion (DE) and diaphragmatic thickness fraction (DTF) was conducted at the patient's bedside every 48 h for ventilated patients and every 72 h for nonventilated patients until they were weaned from the ventilator or discharged home. Qualitative data are expressed as percentages or numbers, and quantitative data are represented as mean ± standard deviation. Unpaired t-tests were employed to compare continuous variables, and χ2 tests were used for categorical variables. Contingency table analysis was used to compute relative risks in comparing the baseline DE and DTF with the sequential changes in these values.

RESULTS

In cases in which the baseline left DE measured less than 1 cm, the relative risk for the requirement of ventilation was 2.5 times higher, with a confidence interval of 0.62-0.99 (P = 0.19). Notably, a bilateral reduction in DE within the initial 48 h of admission was identified as predictive of need for intubation. When comparing ventilated and nonventilated patients, it was observed that the mean DE values for the left and right sides in ventilated patients (0.74 and 0.79) were significantly lower than those in nonventilated patients (1.3 and 1.66), with corresponding P values of 0.05 and 0.01, respectively. Furthermore, a decline in right DE by more than 50% within 72 h of admission presented a relative risk of 3.3 for the necessity of ventilation, with a confidence interval of 1.29-8.59 (P = 0.01). Duration of ventilation ranged from 2 to 45 days, with an average of 13.14 days, whereas the mean ventilator-free days recorded was 13.57. Notably, a sequential increase in bilateral DE correlated with an extended duration of ventilator-free days.

CONCLUSIONS

The presence of a baseline left DE of less than 1 cm, a consecutive decrease in DE measurements within 48 h, and a comparative reduction in right DE of more than 50% within the initial 3 days are indicators associated with the requirement for MV in patients with NM disease. Furthermore, the upward trajectory of DE in mechanically ventilated patients is linked to an increased number of days free from ventilator support, suggesting its potential to forecast earlier weaning.

Identifying patients at risk for myasthenic crisis with hemogram and inflammation-related laboratory parameters - a pilot study

Background

Myasthenia gravis (MG) is a rare autoimmune disease characterized by fatigable weakness of the voluntary muscles and can exacerbate to life-threatening myasthenic crisis (MC), requiring intensive care treatment. Routine laboratory parameters are a cost-effective and widely available method for estimating the clinical outcomes of several diseases, but so far, such parameters have not been established to detect disease progression in MG.

Methods

We conducted a retrospective analysis of selected laboratory parameters related to inflammation and hemogram for MG patients with MC compared to MG patients without MC. To identify potential risk factors for MC, we applied time-varying Cox regression for time to MC and, as a sensitivity analysis, generalized estimating equations logistic regression for the occurrence of MC at the next patient visit.

Results

15 of the 58 examined MG patients suffered at least one MC. There was no notable difference in the occurrence of MC by antibody status or sex. Both regression models showed that higher counts of basophils (per 0.01 unit increase: HR = 1.32, 95% CI = 1.02-1.70), neutrophils (per 1 unit increase: HR = 1.40, 95% CI = 1.14-1.72), potentially leukocytes (per 1 unit increase: HR = 1.15, 95% CI = 0.99-1.34), and platelets (per 100 units increase: HR = 1.54, 95% CI = 0.99-2.38) may indicate increased risk for a myasthenic crisis.

Conclusion

This pilot study provides proof of the concept that increased counts of basophils, neutrophils, leukocytes, and platelets may be associated with a higher risk of developing MC in patients with MG.

Weaning and extubation failure in myasthenic crisis: a multicenter analysis

Myasthenic crisis (MC) requiring mechanical ventilation is a serious complication of myasthenia gravis (MG). Here we analyze the frequency and risk factors of weaning- and extubation failure as well as its impact on the clinical course in a large cohort. We performed a retrospective chart review on patients treated for MC in 12 German neurological departments between 2006 and 2015. Weaning failure (WF) was defined as negative spontaneous breathing trial, primary tracheostomy, or extubation failure (EF) (reintubation or death). WF occurred in 138 episodes (64.2%). Older Age (p = 0.039), multiple comorbidities (≥ 3) (p = 0.007, OR = 4.04), late-onset MG (p = 0.004, OR = 2.84), complications like atelectasis (p = 0.008, OR = 3.40), pneumonia (p < 0.0001, OR = 3.45), cardio-pulmonary resuscitation (p = 0.005, OR = 5.00) and sepsis (p = 0.02, OR = 2.57) were associated with WF. WF occurred often in patients treated with intravenous immungloblins (IVIG) (p = 0.002, OR = 2.53), whereas WF was less often under first-line therapy with plasma exchange or immunoadsorption (p = 0.07, OR = 0.57). EF was observed in 58 of 135 episodes (43.0%) after first extubation attempt and was related with prolonged mechanical ventilation, intensive care unit stay and hospital stay (p ≤ 0.0001 for all). Extubation success was most likely in a time window for extubation between day 7 and 12 after intubation (p = 0.06, OR = 2.12). We conclude that WF and EF occur very often in MC and are associated with poor outcome. Older age, multiple comorbidities and development of cardiac and pulmonary complications are associated with a higher risk of WF and EF. Our data suggest that WF occurs less frequently under first-line plasma exchange/immunoadsorption compared with first-line use of IVIG.

Greater Number of Plasma Exchanges Does Not Improve Outcome in Myasthenic Crisis

OBJECTIVES

To determine the relationship between the number of plasma exchanges and clinical outcome in patients experiencing myasthenic crisis.

METHODS

We retrospectively reviewed all episodes of myasthenia gravis exacerbation/crisis who received plasmapheresis in patients admitted to a single-center tertiary care referral center from July 2008 to July 2017. We performed statistical analyses to determine whether the increased number of plasma exchanges improves the primary outcome (hospital length of stay) and the secondary outcome (disposition to home, skilled nursing facility, long-term acute care hospital, or death).

RESULTS

There is neither clinically observable nor statistically significant improvement in length of stay or disposition on discharge in patients who received 6 or greater sessions of plasmapheresis.

CONCLUSIONS

This study provides class IV evidence that extending the number of plasma exchanges beyond 5 does not correlate with decreased hospital length of stay or improved discharge disposition in patients experiencing myasthenic crisis.

Application of lymphoplasmapheresis in the treatment of severe myasthenia gravis

Background

Lymphoplasmapheresis (LPE) is a treatment that combines traditional plasma exchange and lymphocyte removal technique. It has been applied to treat a variety of autoimmune diseases, but its application value in the treatment of severe myasthenia gravis (MG) is not yet clear. Therefore, the aim of this study was to investigate the efficacy and safety of LPE in severe MG.

Methods

Clinical data of 123 severe patients with MG (Myasthenia Gravis Foundation of America Clinical Classification, Class IV) who received LPE treatment were included in a retrospective analysis. Efficacy was evaluated by the change of Quantitative Myasthenia Gravis score (QMGS) before and after treatment. Univariate and multivariate logistic regression analysis was used to explore clinical factors affecting efficacy.

Results

A total of 220 replacements were performed in 123 patients, with an average of 1.79 replacements per patient. The overall safety of LPE was good, and no serious adverse reactions occurred. After treatment, the mean QMGS of patients decreased significantly, from 23.40 ± 4.25 points before treatment to 17.93 ± 5.61 points after treatment, a decrease of 5.47 ± 4.16 points. 75.6% of patients experienced remission of clinical symptoms. During a 2-month follow-up of 64 patients, a progressive improvement in QMGS was found. Each muscle group involved in MG responded well to LPE treatment. In addition, LPE significantly reduced the levels of AChR-Ab and inflammatory cytokines in patients. Age ≥ 50 years and co-infection were unfavorable factors affecting the efficacy.

Conclusions

In this study cohort, LPE is safe for the treatment of severe MG and achieves good treatment outcome with fewer replacements. In patients with MG, the avoidance and timely control of infection are necessary. Our study provides a potential new treatment option for severe MG.

Poor responses and adverse outcomes of myasthenia gravis after thymectomy: Predicting factors and immunological implications

Myasthenia gravis (MG) has been recognized as a series of heterogeneous but treatable autoimmune conditions. As one of the indispensable therapies, thymectomy can achieve favorable prognosis especially in early-onset generalized MG patients with seropositive acetylcholine receptor antibody. However, poor outcomes, including worsening or relapse of MG, postoperative myasthenic crisis and even post-thymectomy MG, are also observed in certain scenarios. The responses to thymectomy may be associated with the general characteristics of patients, disease conditions of MG, autoantibody profiles, native or ectopic thymic pathologies, surgical-related factors, pharmacotherapy and other adjuvant modalities, and the presence of comorbidities and complications. However, in addition to these variations among individuals, pathological remnants and the abnormal immunological milieu and responses potentially represent major mechanisms that underlie the detrimental neurological outcomes after thymectomy. We underscore these plausible risk factors and discuss the immunological implications therein, which may be conducive to better managing the indications for thymectomy, to avoiding modifiable risk factors of poor responses and adverse outcomes, and to developing post-thymectomy preventive and therapeutic strategies for MG.

Our Clinical Experience in the Treatment of Myasthenia Gravis Acute Exacerbations with a Novel Nanomembrane-Based Therapeutic Plasma Exchange Technology

According to the American Academy of Neurology 2011 guidelines, there is insufficient evidence to support or refute the use of therapeutic plasma exchange (TPE) for myasthenia gravis (MG). The goal of this study was to determine whether a novel nanomembrane-based TPE could be useful in the treatment of MG. Thirty-six adult patients, MGFA 4/4B and 5, with acute MG episodes were enrolled into a single-center retrospective before-and-after study to compare a conventional treatment group (n = 24) with a nanomembrane-based TPE group (n = 12). TPE or intravenous immunoglobulins (IVIG) infusions were used in impending/manifested myasthenic crises, especially in patients at high-risk for prolonged invasive ventilation (IMV) and in those tolerating non-invasive ventilation (NIV). The clinical improvement was assessed using the Myasthenia Muscle Score (0–100), with ≥20 increase for responders. The primary outcome measures included the rates of implemented TPE, IVIG, and corticosteroids immunotherapies, NIV/IMV, early tracheotomy, MMS scores, extubation time, neuro-ICU/hospital LOS, complications, and mortality rates. The univariate analysis found that IMV was lower in the nanomembrane-based group (42%) compared to the conventional treatment group (83%) (p = 0.02). The multivariate analysis using binary logistic regression revealed TPE and NIV as independent predictors for short-term (≤7 days) respiratory support (p = 0.014 for TPE; p = 0.002 for NIV). The novel TPE technology moved our clinical practice towards proactive rather than protective treatment in reducing prolonged IMV during MG acute exacerbations.

Pneumonia in Nervous System Injuries: An Analytic Review of Literature and Recommendations

Pneumonia is one of the most common complications in intensive care units and is the most common nosocomial infection in this setting. Patients with neurocritical conditions who are admitted to ICUs are no exception, and in fact, are more prone to infections such as pneumonia because of factors such as swallow dysfunction, need for mechanical ventilation, longer length of stay in hospitals, etc. Common central nervous system pathologies such as ischemic stroke, traumatic brain injury, subarachnoid hemorrhage, intracerebral hemorrhage, neuromuscular disorders, status epilepticus, and demyelinating diseases can cause long in-hospital admissions and increase the risk of pneumonia each with a mechanism of its own. Brain injury-induced immunosuppression syndrome is usually considered the common mechanism through which patients with critical central nervous system conditions become susceptible to different kinds of infection including pneumonia. Evaluating the patients and assessment of the risk factors can lead our attention toward better infection control in this population and therefore decrease the risk of infections in central nervous system injuries.

Independent risk factors for myasthenic crisis and disease exacerbation in a retrospective cohort of myasthenia gravis patients

BACKGROUND

Myasthenic crisis (MC) and disease exacerbation in myasthenia gravis (MG) are associated with significant lethality and continue to impose a high disease burden on affected patients. Therefore, we sought to determine potential predictors for MC and exacerbation as well as to identify factors affecting outcome.

METHODS

We examined a retrospective, observational cohort study of patients diagnosed with MG between 2000 and 2021 with a mean follow-up of 62.6 months after diagnosis from eight tertiary hospitals in Germany. A multivariate Cox regression model with follow-up duration as the time variable was used to determine independent risk factors for MC and disease exacerbation.

RESULTS

815 patients diagnosed with MG according to national guidelines were included. Disease severity at diagnosis (quantitative MG score or Myasthenia Gravis Foundation of America class), the presence of thymoma and anti-muscle specific tyrosine kinase-antibodies were independent predictors of MC or disease exacerbation. Patients with minimal manifestation status 12 months after diagnosis had a lower risk of MC and disease exacerbation than those without. The timespan between diagnosis and the start of immunosuppressive therapy did not affect risk. Patients with a worse outcome of MC were older, had higher MGFA class before MC and at admission, and had lower vital capacity before and at admission. The number of comorbidities, requirement for intubation, prolonged mechanical ventilation, and MC triggered by infection were associated with worse outcome. No differences between outcomes were observed comparing treatments with IVIG (intravenous immunoglobulin) vs. plasma exchange vs. IVIG together with plasma exchange.

CONCLUSIONS

MC and disease exacerbations inflict a substantial burden of disease on MG patients. Disease severity at diagnosis and antibody status predicted the occurrence of MC and disease exacerbation. Intensified monitoring with emphasis on the prevention of infectious complications could be of value to prevent uncontrolled disease in MG patients.

Cardiac disorders worsen the final outcome in myasthenic crisis undergoing non-invasive mechanical ventilation: a retrospective 20-year study from a single center

The study was performed to evaluate the impact of cardiological disorders on the outcome of myasthenic crisis (MC) requiring ventilation. The study includes 90 cases admitted to the Neurology Unit of Modena, Italy (January 2000 - September 2020). All patients were eligible for a non-invasive ventilation (NIV) trial. We analyzed the effect of cardiac comorbidities on the outcomes, which were the need of invasive ventilation, the risk tracheostomy for weaning failure and the duration of intensive care unit (ICU) stay Females were 58.9% and males 41.1%. Median age at diagnosis was 59 and at MC was 65. Patients were classified as early (EOMG) or late (LOMG), 34.4 and 65.6% respectively, according to age above or below 50; 85% of patients were anti- AChR antibody positive. Hypertension and cardiac diseases occurred at the diagnosis in 61 and 44.4%, respectively. Invasive mechanical ventilation (MV) was needed in 34% of cases. Nine subjects (10%) underwent tracheostomy because of weaning failure. Independent predictors of NIV failure were atrial fibrillation (AF), either parossistic or persistent (OR 3.05, p < 0.01), hypertensive cardiopathy (HHD) (OR 2.52, p < 0.01) and ischaemic heart disease (IHD) (OR 3.08, p < 0.01). Hypertension (HT) had no statistical effect on the outcomes. HHD was a predictor of weaning failure (OR 4.01, p = 0.017). Our study shows that HHD, AF and IHD increase the risk of NIV failure in MC receiving ventilation.

Predictors of outcome in patients with myasthenic crisis undergoing non-invasive mechanical ventilation: A retrospective 20 year longitudinal cohort study from a single Italian center

About 20% of patients with myasthenia gravis (MG) may develop myasthenic crisis (MC) requiring ventilation, either invasive (MV) or non-invasive (NIV) and intensive unit care (ICU). NIV failure in patients with MC can occur up to 60% of cases admitted to ICU. Moreover it is not known the outcome of MC receiving NIV. Purpose of this study was to identify predictors of outcome in MC who underwent non-invasive ventilator support outside ICU setting. We enrolled 90 patients, 53 females and 37 males admitted to University Hospital of Modena (Italy) between January 2000 and September 2020. Median age at MC was 65 years. Thirty-four patients (37.8%) required MV. Thymectomy was performed in 45 cases, associated with thymoma in 55%, with hyperplastic thymus in 33%. First-line treatment was plasmaexchange (38.8%) or intravenous immunoglobulins (45.6%). Males exhibited higher risk of MV than females .Patients in MV were treated with plasmaexchange as first-line therapy . Our in-hospital mortality rate was low. Nine patients underwent tracheostomy which was significantly related to male gender. Comorbidities had significant effect on length of ICU .Our study confirms as predictors of prognosis in our patients male gender, older age at onset, infections as trigger, pneumonia.

Hemogram parameters can predict in-hospital mortality of patients with Myasthenic crisis

BACKGROUND

Myasthenia gravis (MG) is an autoimmune disease involving the neuromuscular junction. Myasthenic crisis (MC), which is characterized by respiratory failure and the requirement of mechanical ventilation in patients with MG, is still a medical emergency despite the decrease in mortality with the advances in acute management. Hemogram is a cost-effective test for evaluating hematological complications and systemic inflammation, and hemogram data have been used to predict various clinical outcomes of several diseases. The relationship between hemogram and MG has been discussed, but the role of hemogram data in predicting the prognosis of MC patients has not been established.

METHODS

To identify whether hemogram data can predict in-hospital mortality in patients with MC, we retrospectively investigated 188 myasthenic crisis events from the Chang Gung Research Database between April 2001 and March 2019. Demographic and clinical characteristics were collected, as well as hemogram data before intubation and extubation. The endpoints were mortality during mechanical ventilation and mortality after extubation.

RESULTS

The overall in-hospital mortality rate was 22%. Multivariate logistic regression analysis for predicting mortality during mechanical ventilation showed that old age at MC onset (OR = 1.039, p = 0.022), moderate-to-severe anemia (OR = 5.851, p = 0.001), and extreme leukocytosis (OR = 5.659, p = 0.022) before intubation were strong predictors of mortality, while acute management with plasma exchange or double-filtration plasmapheresis (PE/DFPP) significantly decreased mortality (OR = 0.236, p = 0.012). For predicting mortality after extubation, moderate-to-severe anemia before extubation (OR = 8.452, p = 0.017) and non-treated with disease-modifying therapy before MC (OR = 5.459, p = 0.031) were crucial predictive factors.

CONCLUSION

This study demonstrated that both old age at MC onset and moderate-to-severe anemia are important predictors of in-hospital mortality in patients with MC, and extreme leukocytosis is another crucial predictor of mortality during mechanical ventilation. The suggested mechanism is that anemia-induced hypoxia may enhance the release of proinflammatory cytokines, exacerbate systemic inflammation, and lead to multiple organ dysfunction syndrome and, finally, mortality.

Neuromuscular Disorders in the Intensive Care Unit

PURPOSE OF REVIEW

This article discusses the pathophysiology, presentation, diagnosis, treatment, and prognosis of common neuromuscular disorders seen in the intensive care unit, including Guillain-Barré syndrome, myasthenia gravis, and intensive care unit-acquired weakness.

RECENT FINDINGS

Guillain-Barré syndrome can have an excellent prognosis if patients are diagnosed early, appropriately treated, and monitored for complications, including respiratory failure and dysautonomia. Intensive care unit-acquired weakness increases overall mortality in patients who are critically ill, and distinguishing between critical illness myopathy and critical illness polyneuropathy may have important prognostic implications.

SUMMARY

Neuromuscular disorders are not rare in the intensive care unit setting, and precise identification and treatment of these conditions can greatly impact long-term outcomes.

Frailty for neurologists: a practical guide

Neurologists increasingly care for people with significant frailty in both clinic and ward settings. Such care demands a balanced approach to investigation, diagnosis and treatment, as well-intentioned actions can produce adverse effects. This article presents a practical approach to the identification and management of patients with frailty and neurological conditions. We address medicines optimisation, common causes of deterioration in those with frailty, communication, decisions about intensity of treatment, and shared decision-making including ethical aspects of withholding or withdrawing life-prolonging treatment, with a view to improving the experience both of people living with frailty and of the teams who care for them.

Therapeutic Plasma Exchange in Myasthenia Gravis: A Systematic Literature Review and Meta-Analysis of Comparative Evidence

Background: Patients with Myasthenia Gravis (MG) can be treated acutely with therapeutic plasma exchange (TPE) or intravenous immune globulin (IVIG). To date, there is no definitive understanding of which of the two treatments is more effective and safer. The purpose of this study was to systematically review the literature on the comparative efficacy and safety of TPE to other available treatments for MG. Methods: A systematic literature search for studies published between 1997 and 2017 was performed per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using two database sources, MEDLINE (through the PubMed database) and Cochrane Library. Results: The search strategy resulted in 535 articles whose abstracts were reviewed. Among these, 165 full texts articles were reviewed for eligibility and 101 articles were excluded. Of the 165 articles, 64 articles were included for a systematic literature and 11 articles for a meta-analysis. Conclusions: This systematic literature review and meta-analysis of treatment options showed that there was a higher response rate with TPE than IVIG in acute MG patients and patients undergoing thymectomy. There was no difference in mortality between the two treatment options. Our findings highlight the need for additional randomized clinical trials in these patients with MG.

Risk Factors for Postoperative Myasthenic Crisis After Thymectomy in Patients With Myasthenia Gravis

BACKGROUND

The objective of this study is to characterize postoperative myasthenic crisis (POMC), after extended thymectomy and discuss the treatment options for this condition.

METHODS

Clinical data from patients with generalized myasthenia gravis (MG) who underwent extended thymectomy at Xuanwu Hospital of the Capital Medical University from 2016 to 2018 were reviewed retrospectively. Patients were divided into two groups-POMC and non-POMC. Variables that could potentially predict POMC were analyzed. In the POMC group, the aforementioned variables were compared between patients with and without pneumonia.

RESULTS

Ninety-seven patients were enrolled. Thirty-eight (39.2%) patients developed POMC. The mean duration of mechanical ventilation (MV), length of intensive care unit stay, and duration of hospital stay were significantly longer in the POMC group (P < 0.001). Multivariate logistic regression analysis showed that disease severity, symptom duration longer than 12 mo, and transsternal thymectomy were independent risk factors for POMC. Postoperative pneumonia significantly prolonged the MV period (P = 0.012) and weaning from MV after intravenous immunoglobin (IVIg) treatment (P = 0.005) in POMC patients. Twenty-four (24.7%) POMC patients who received IVIg were successfully weaned from MV and were discharged.

CONCLUSIONS

Disease severity, symptom duration longer than 12 mo, and transsternal thymectomy were independent risk factors for POMC. Postoperative pneumonia worsens the prognosis of POMC.

Early Tracheostomy Is Associated With Shorter Ventilation Time and Duration of ICU Stay in Patients With Myasthenic Crisis-A Multicenter Analysis

BACKGROUND

Myasthenic crisis (MC) requiring mechanical ventilation (MV) is a rare and serious complication of myasthenia gravis. Here we analyzed the frequency of performed tracheostomies, risk factors correlating with a tracheostomy, as well as the impact of an early tracheostomy on ventilation time and ICU length of stay (LOS) in MC.

METHODS

Retrospective chart review on patients treated for MC in 12 German neurological departments between 2006 and 2015 to assess demographic/diagnostic data, rates and timing of tracheostomy and outcome.

RESULTS

In 107 out of 215 MC (49.8%), a tracheostomy was performed. Patients without tracheostomy were more likely to have an early-onset myasthenia gravis (27 [25.2%] vs 12 [11.5%], p = 0.01). Patients receiving a tracheostomy, however, were more frequently suffering from multiple comorbidities (20 [18.7%] vs 9 [8.3%], p = 0.03) and also the ventilation time (34.4 days ± 27.7 versus 7.9 ± 7.8, p < 0.0001) and ICU-LOS (34.8 days ± 25.5 versus 12.1 ± 8.0, p < 0.0001) was significantly longer than in non-tracheostomized patients. Demographics and characteristics of the course of the disease up to the crisis were not significantly different between patients with an early (within 10 days) compared to a late tracheostomy. However, an early tracheostomy correlated with a shorter duration of MV at ICU (26.2 days ± 18.1 versus 42.0 ± 33.1, p = 0.006), and ICU-LOS (26.2 days ± 14.6 versus 42.3 ± 33.0, p = 0.003).

CONCLUSION

Half of the ventilated patients with MC required a tracheostomy. Poorer health condition before the crisis and late-onset MG were associated with a tracheostomy. An early tracheostomy (≤ day 10), however, was associated with a shorter duration of MV and ICU-LOS by 2 weeks.

Myasthenic crisis demanding mechanical ventilation: A multicenter analysis of 250 cases

OBJECTIVE

To determine demographic characteristics, clinical features, treatment regimens, and outcome of myasthenic crisis (MC) requiring mechanical ventilation (MV).

METHODS

Analysis of patients who presented with MC between 2006 and 2015 in a German multicenter retrospective study.

RESULTS

We identified 250 cases in 12 participating centers. Median age at crisis was 72 years. Median duration of MV was 12 days. Prolonged ventilation (>15 days) depended on age (p = 0.0001), late-onset myasthenia gravis (MG), a high Myasthenia Gravis Foundation of America Class before crisis (p = 0.0001 for IVb, odds ratio [OR] = infinite), number of comorbidities (>3 comorbidities: p = 0.002, OR 2.99), pneumonia (p = 0.0001, OR 3.13), and resuscitation (p = 0.0008, OR 9.15). MV at discharge from hospital was necessary in 20.5% of survivors. Patients with early-onset MG (p = 0.0001, OR 0.21), thymus hyperplasia (p = 0.002, OR 0), and successful noninvasive ventilation trial were more likely to be ventilated for less than 15 days. Noninvasive ventilation in 92 cases was sufficient in 38%, which was accompanied by a significantly shorter duration of ventilation (p = 0.001) and intensive care unit (ICU) stay (p = 0.01). IV immunoglobulins, plasma exchange, and immunoadsorption were more likely to be combined sequentially if the duration of MV and the stay in an ICU extended (p = 0.0503, OR 2.05). Patients who received plasma exchange or immunoadsorption as first-line therapy needed invasive ventilation significantly less often (p = 0.003). In-hospital mortality was 12%, which was significantly associated with the number of comorbidities (>3) and complications such as acute respiratory distress syndrome and resuscitation. Main cause of death was multiorgan failure, mostly due to sepsis.

CONCLUSION

Mortality and duration of MC remained comparable to previous reports despite higher age and a high disease burden in our study. Prevention and treatment of complications and specialized neurointensive care are the cornerstones in order to improve outcome.

Intravenous immunoglobulin to prevent myasthenic crisis after thymectomy and other procedures can be omitted in patients with well-controlled myasthenia gravis

Background:

Myasthenic crisis (MC) is a potentially life-threatening complication of myasthenia gravis. Its precipitating factors include surgical procedures, particularly thymectomy. The role of preoperative intravenous immunoglobulin (IVIg) in preventing MC in patients scheduled for thymectomy and other surgery with general anaesthesia is unknown. Our objective was to test the hypothesis that preoperative IVIg is effective in preventing myasthenic crisis in patients with myasthenia gravis scheduled for surgery under general anaesthesia, including thymectomy.

Methods:

A prospective, randomized, double-blind, single-centre study was conducted over a 4-year period. The treatment group received IVIg, 0.4 g/kg/day preoperatively for 5 consecutive days, and the placebo group received saline solution under the same conditions. The two groups were age-matched, with similar functional status, and Myasthenia Gravis Foundation of America class. All patients had well-controlled myasthenia gravis with minimal manifestations before surgery. The primary outcome measured was MC. Intubation times, time in the recovery room, number of postoperative complications, and days of hospitalization were the secondary outcomes measured.

Results:

A total of 47 patients were randomized, 25 to the IVIg group and 22 to placebo. There were 19 men and 28 women, with a mean age of 58.6 years, mean body mass index of 27.8 kg/m², and mean acetylcholine receptor antibodies of 12.9 nmol/l. The mean forced vital capacity was 84.4%. The mean quantitative myasthenia gravis sum score was 6.3. Ten patients (five in each arm) had a history of MC. Thymectomy was performed in 16 patients. Only one patient in the placebo group presented with MC requiring non-invasive ventilation (but no reintubation) for 6 days. Neither differences between groups in the univariate analysis nor risk factors for MC in the multivariate analysis were found.

Conclusions:

Preoperative IVIg to prevent MC does not appear to be justified in well-controlled myasthenia gravis patients. This study provides class I evidence that preparation with IVIg to prevent MC is not necessary in well-controlled myasthenia gravis patients scheduled for surgery with general anaesthesia.

Myasthenia Gravis and Thymoma Surgery: A Clinical Update for the Cardiothoracic Anesthesiologist

Myasthenia gravis (MG) is a rare neuromuscular disorder characterized by skeletal muscle weakness. Patients with MG who have thymoma and thymic hyperplasia have indications for thymectomy. The perioperative care of patients with MG scheduled for thymus resection should be focused on optimizing their neuromuscular function, identifying factors related to postoperative mechanical ventilation, and avoiding of triggers associated with myasthenic or cholinergic crisis. Minimally invasive surgical techniques, use of regional analgesia, and avoidance or judicious administration of neuromuscular blocking drugs (NMBs) is recommended during the perioperative period. If NMBs are used, sugammadex appears to be the drug of choice to restore adequately the neuromuscular transmission. In patients with postoperative myasthenic crisis, plasma exchange or intravenous immune globulin and mechanical support is recommended.

Perianesthetic Implications and Considerations for Myasthenia Gravis

Myasthenia gravis (MG) is a chronic autoimmune neuromuscular disease in which antibodies against the post-nicotinic acetylcholine receptor at the neuromuscular junction develop. Although the exact cause of MG remains unknown, the thymus is a common factor in many cases. Patients with underlying junctional disease, such as MG, have greater anesthesia-related risks because of their known predisposition toward prolonged muscle weakness. Medications given in the perioperative period, such as anesthetic agents, antibiotics, cardiovascular drugs, and corticosteroids, affect neuromuscular transmission that contributes to muscle weakness. Judicious use of neuromuscular blocking agents for patients with MG must be considered. This patient population is at high risk for respiratory failure, and therefore must be carefully assessed throughout the perioperative period to ensure that a regular spontaneous respiratory pattern is sufficient to provide adequate oxygenation. Perianesthesia providers must consider anesthetic, ventilatory, and pharmacologic implications when proposing, providing, and recovering anesthesia for the patient with MG.