Respiratory Referrals And Non- invasive Ventilation Utilisation In Motor Neuron Disease Patients In Southern District Health Board
Aims: 1.Evaluate timeliness of respiratory referrals, first specialist reviews after referrals, time to baseline lung function testing and non- invasive ventilation (NIV) initiation after motor neuron disease (MND) diagnosis 2.Otago DHB and Southland DHB merged to form Southern DHB in 2010. Important to evaluate if any variation in service provision after merging of DHBs. 3.Establish rate of NIV use in the Southern DHB cohort and barriers to use 4.Evaluate trends of lung function tests (LFT)with time for patients with MND 5.Investigate if there is a difference in survival times for MND patients on NIV and those without.
Patients identified through the Southern DHB MND clinic lists from February 2014 to December 2019. Health Connect South records assessed October 2020 to January 2021. Patients with MND diagnosed in Southern DHB and had all follow-up in SDHB were included in analysis. Two -tailed t tests were used for statistical analysis to obtain p values.
67patients analysed. 97% of patients referred to respiratory, 96% had baseline LFTs. 38 patients in Otago (mean 25.1 days, SD 45.7) demonstrated significantly shorter time to referrals than Southland (mean 81.4 SD 112), t(29)=-2.38 , p0.02. There was no significant difference in time seen in clinic or baseline LFT. Rate of NIV use 28.4%. Main reason for no NIV is because NIV not indicated. LFT trend declined linearly as expected with time. There was no significant difference in survival time from MND diagnosis between non- NIV and NIV group with patients living 753.9 and 742.6 days respectively.
Conclusions 1.Significant difference in time to respiratory referrals. Likely due to some patients diagnosed prior to merge and regionalisation of Neurology service 2.NIV use 28% and comparable to international standards 3.No difference in survival time between NIV and non- NIV groups
Tuberculosis Treatment In A Patient With Myasthenia Gravis
Case: 21year old woman of mixed Thai and New Zealand European heritage presented to Neurology with a 2month history of dyspnoea and generalised fatigue. Background significant for generalised myasthenia gravis stable on immunosuppression and pyridostigmine. Investigations revealed disseminated tuberculosis which was rifampicin “hetero- resistant”. This is a complex case of drug resistant tuberculosis treatment in a patient with myasthenia gravis.
Discussion: Patients with myasthenia gravis on immunosuppression are at a higher risk of developing active tuberculosis. Treatment of drug resistant tuberculosis in patients with myasthenia gravis is challenging given there are many medications that can cause neuromuscular blockade and lead to exacerbation of disease.
Conclusion: Immunosuppression can reactivate quiescent infection or worsen the clinical effects of infection. Patients need to be screen prior to commencement of immunosuppression. Prophylactic therapy for tuberculosis may be warranted if latent tuberculosis is found pre- immunosuppression
Clinical practise point: 1.Not all myasthenia gravis patients with dyspnoea have an exacerbation of their disease. Always think of atypical infections given immunosuppressed 2.There are many medications that can cause myasthenic exacerbations. Physicians should be aware of them. 3.Prior to immunosuppression use, patients need to be screened with full blood count, infection screen, CXR, QuantiFERON- TB Gold, Hepatitis B, C, HIV, varicella, rubella and measles serology
References •Ou, SM, Liu CJ, Chang YS et al (2013) Tuberculosis in myasthenia gravis. International journal of tuberculosis and lung disease. 17(1):79–84 •Steyn EC, Naidoo TM, Marais S, Heckmann JM (2021) Tuberculosis in Myasthenia Gravis patients on immunosuppressive therapy in a high-risk area: Implications for preventative therapy. Journal of neuroscience. 425: 117447. •Hasan T, Au E, Chen S, Tong A, Wong G (2018). Screening and prevention for latent tuberculosis in immunosuppressed patients at risk for tuberculosis: a systematic review of clinical practice guidelines. BMJ Open.8:e022445. doi:10.1136/ bmjopen-2018-022445