New diagnosis myasthenia gravis and preeclampsia in late pregnancy

Abstract

SUMMARYMyasthenia gravis is a chronic autoimmune disease of neuromuscular transmission resulting in fatigable skeletal muscle weakness. Preeclampsia is a multisystem disease of pregnancy which is characterised by hypertension and involvement of one or more organ systems. Both diseases are responsible for considerable morbidity and mortality for mother and fetus. The occurrence of both preeclampsia and myasthenia gravis in pregnancy is very rare, and conflicts arise when considering the optimal management of each disease.We present a case of a parturient who was newly diagnosed with both myasthenia gravis and preeclampsia in late pregnancy. Myasthenia treatment was started with prednisolone and pyridostigmine, and delivery was by caesarean section at 37 weeks gestation under spinal anaesthesia. Postnatally, the patient developed worsening of myasthenia and preeclampsia symptoms. We consider the anaesthetic implications for both diseases and describe our approach for the management of this case. BACKGROUND

Severe Preeclampsia in the Setting of Myasthenia Gravis

“…Of the reported cases, seven patients received regional anesthesia. One of those patients had profound vagal bradycardia following neuraxial anesthetic blockage, which required atropine and ephedrine to resolve [ 14 ]. General anesthesia with intubation was performed in only one case, and prolonged ventilation was needed postpartum.…”

“…Calcium channel blockers and β -blockers can exacerbate MG symptoms [ 14 ]. Hence, their use should be avoided if possible for a patient with MG. Methyldopa and hydralazine are considered safe to use in MG patients.…”

Neuromuscular Disorders in Pregnancy

“…3,34 Methyldopa and hydralazine can also be considered for management hypertension in MG patients with these disorders. 35 Some infections, particularly urinary tract infections and chorioamnionitis, are more common in pregnancy. These may precipitate exacerbation of MG and should be treated promptly with antibiotics appropriate for use in MG and in pregnancy.…”

Myasthaenia Gravis: Clinical management issues before, during and after pregnancy

“…31 Both β-blockers and calcium channel blockers can potentially worsen myasthaenic symptoms and thus should be avoided. 30 …”

“…4 The treatment of hypertension is a cornerstone of pre-eclampsia management; methyldopa and oral hydralazine can be considered the initial drugs of choice to control non-severe hypertension, while intravenous hydralazine should be used to reduce acute blood pressure in severe hypertensives (systolic pressure of >160 mmHg or diastolic pressure of >110 mmHg). 30 However, in comparison to hydralazine, intravenous urapidil has shown better tolerability and controllability and is a promising alternative. 31 Both β-blockers and calcium channel blockers can potentially worsen myasthaenic symptoms and thus should be avoided.…”