Anaesthetic management of labour and delivery in the parturient with mitochondrial myopathy

Purpose: We describe the anaesthetic management for Caesarean section in a parturient with a defect in complex 111 of the respiratory chain who had increased lactate concentrations at rest and with exercise. Clinical features: We administered effective epidural anaesthesia with lidocaine for Caesarean delivery. The serum lactate concentration was less than the preoperative value both during and after surgery. Shivering during the perioperative period was avoided by administering warm iv fluids, warm local anaesthetic solution and epidural meperidine. Pain relief after surgery was provided with iv PCA morphine augmented by local infiltration with bupivacaine to fascia and skin edges and epidural injection with meperidine. Conclusion: Mitochondrial myopathies are an uncommon group o f disorders in which mitochondrial dysfunction leads to clinical disease of muscle and sometimes of other organs with high energy requirements. The management of labour and delivery in women with mitochondrial myopathies should be individualized according to severity of disease and .formulated by consultation between attending physicians and the anaesthetist. Epidural analgesia reduces stress and work associated with labour and reduces oxygen demand during labour. However, parturients with defects of the respiratory chain with documented increased lactate concentrations at rest and with exercise are best managed with elective Caesarean deliv- - ery with regional anaesthesia to prevent life-threatening lactic acidosis during labour. The association between malignant hyperthermia and these disorders has not been proved, but it appears prudent to consider these women as MH susceptible until definitive data regarding this possible relationship are available. Objectif" Prdsenter la gestion anethdsique d'un cdsarienne rdalisde chez une parturiente porteuse d'une anomalie du complexe 11I de la chaine respiratoire avec des concentrations de lactate dlevdes rant au repos qu 'it l' exercice. Caract~ristiques cliniques: Les auteurs ont r~alisd avec succ~s une ~pidurale ~ la lidoca~ne pour la cdsarienne. La concentration de lactate a dtd moins dlev~e pendant et apr~s la chirurgie qu'~t la pdriode prdopdratoire. Le frisson a ~td prdvenu par l'administration de liquides et d'une solution anesthdsique et de mdpdridine r~chauff~es. Apr~s la chirurgie, la douleur a did trait~e avec de la morphine i.v. auto-administr~e aprks une infiltration de bupivaca'fne clans les fascia et les l~vres de la plaie et l'administration de mdpdridine dpidurale. Conclusion: Les myopathies mithocondriques constituent un groupe rare d'affections caractdrisdes par le dysfonctionnement des mitochondries qui atteint les muscles et quelquefois d'autres organes dont les besoins dnergdtiques sont ~lev~s. La gestion du travail et de l'accouchement des porteuses de myopathies mitochondriques doivent tenir compte de la gravit~ de la maladie et amener les mddecins traitants et l'anesthdsiste fi se consulter. L 'analgdsie dpidurale diminue le stress et l'effort qui accompagnent le travail et rdduit la consommation en oxyg~ne. Cependant, la prise en charge des parturientes dont la chatne respiratoire est ddficiente et qui pr~sentent une augmentation document~e de la lactas~mie au repos et ?t l' exercice ndcessite l' exdcution d'une cdsarienne en chirurgie programmde et rdglde sous anesthdsie rdgionale dans le but de prdvenir une acidose lactique potentiellement fatale pendant le travail. L'association entre l'hyperthermie maligne et ces affections n 'a pas dtd prouvde mais il est sage de considdrer ces patientes comme susceptibles jusqu '?tce que des donndes ddfinitives concernant cette relation soient disponsibles. Mitochondrial myopathies are a heterogenous group of disorders of muscle energy metabolism. The mitochondria produce the energy requirements of muscle cells through the redox reactions of the electron transfer chain and oxidative phosphorylation, thereby producing ATP.I There are reports of pregnancy and uneventful vaginal delivery in a woman with metabolic myopathy and pre-eclampsia,2 and of Caesarean delivery in a woman with carnitine palmitoyl transferase (CPT) deficiency. 3 However, there is no report of pregnancy in a woman with mitochondrial myopathy due to a defect of the respiratory chain and elevated serum lactate concentrations at rest and with exercise. We describe the results of exercise testing in this patient and our experience of the anaesthetic management for Caesarean section. Case report The patient developed initial muscle cramps and exercise intolerance at 12 yr of age. Ten years later she was referred to a respirologist because of increasing shortness of breath and leg cramps on walking more than two flights of stairs. More strenuous exercise caused palpitations, nausea and vomiting. After 15-20 min rest the symptoms would abate. She has 10 siblings who are all well, and there is no family history of a similar condition. Initial investigations at 22 yr revealed BP 110/70 mmHg with heart rate of 80-min -l and respiratory rate of 18- min-~ at rest. Musculo-skeletal and neurological examinations were normal. The ECG showed Wolf-Parkinson-White (WPW) syndrome, but echocardiography confirmed normal ventricular size and function without valvular abnormalities. Her spirometry was normal with a vital capacity of 3 L (86% of predicted). Arterial blood gas analysis at rest was also normal. Maximum inspiratory pressure was - 2 5 cm H20. (normal - 5 0 to - 1 0 0 cm H20 ). An exercise test was performed at light workloads with and without an indwelling pulmonary artery catheter for five minutes with 20 min rest between measurements (Table I). This test showed low oxygen consumption with greater CO 2 production than predicted, indicating impaired oxygen utilization by exercising muscles. Cardiac output increased appropriately indicating a normal cardiac response to exercise. Profound metabolic acidosis developed during exercise as a result of lactate accumulation. Microscopic examination of muscle fibres from the quadriceps revealed frequent "red-ragged fibres" with subsarcolemmal accumulation of red material in Gomori stain, a frequent finding in patients with mitochondrial myopathy. Biochemical examination indicated a defect in complex III of the electron transport chain. She was TABLE l Exercise testing Rest lOOkpm 150kpm 200kpm* l. 19 7.35 100 33 21 3.8 3.3 2.1 7.29 132 30 14 12,7 7.7 1.3 7.21 134 24 9 17,4 8.2 2.6 7.07 2709 25 7 therefore prescribed ascorbic acid 1G q.i.d, and Vitamin K 10 mg o.d. and discharged home. In 1987, at 26 yr, she delivered a live female infant at 25 wk gestation. This infant died of respiratory complications due to prematurity. The following year she was admitted at 26 wk gestation with sponta~neous uterine contractions which abated following iv fluid bolus and bedrest. Before admission she had experienced increasing dyspnea with minor exertion and intermittent palpitations. Her EC (...truncated)