Mier A, Brophy C, Wass J A, Besser G M, Green M
Department of Respiratory Muscle Physiology, Brompton Hospital, London, United Kingdom.
Am Rev Respir Dis. 1989 Feb;139(2):529-33. doi: 10.1164/ajrccm/139.2.529.
Breathlessness is a common complaint in patients with hyperthyroidism, and respiratory failure requiring artificial ventilation, although rare, can occur. While a proximal myopathy is frequently recognized, diaphragm muscle function has not hitherto been studied in detail in thyrotoxicosis. The strength of the quadriceps femoris and respiratory muscles was therefore assessed in seven consecutive thyrotoxic patients, on presentation and during medical treatment, when euthyroid. Prior to therapy, reduced quadriceps muscle strength, vital capacity, and global expiratory and inspiratory muscle strength were found. Diaphragmatic weakness was present in one of four patients studied by measuring transdiaphragmatic pressures during maximal sniffs and during bilateral phrenic nerve stimulation at 1 Hz (twitch). After treatment, significant improvement occurred in quadriceps muscle strength, vital capacity, and global respiratory muscle strength. Sniff and twitch transdiaphragmatic pressures also increased significantly. These results indicate that respiratory muscle weakness occurs in hyperthyroidism and that such weakness is reversible with medical treatment. It is important to realize that respiratory muscles may be directly affected when assessing thyrotoxic patients with breathlessness, as severe involvement of the respiratory muscles may cause respiratory failure.
呼吸困难是甲状腺功能亢进患者的常见主诉，虽然需要人工通气的呼吸衰竭很少见，但仍可能发生。虽然近端肌病经常被认识到，但迄今为止，甲状腺毒症患者的膈肌功能尚未得到详细研究。因此，对7例连续的甲状腺毒症患者在就诊时以及甲状腺功能正常接受药物治疗期间，评估了股四头肌和呼吸肌的力量。治疗前，发现股四头肌力量、肺活量以及整体呼气和吸气肌力量均降低。通过在最大吸气时测量跨膈压以及在双侧膈神经以1 Hz（抽搐）刺激时，在4例研究患者中有1例存在膈肌无力。治疗后，股四头肌力量、肺活量和整体呼吸肌力量有显著改善。吸气和抽搐时的跨膈压也显著增加。这些结果表明，甲状腺功能亢进时会发生呼吸肌无力，并且这种无力通过药物治疗是可逆的。重要的是要认识到，在评估有呼吸困难的甲状腺毒症患者时，呼吸肌可能会受到直接影响，因为呼吸肌的严重受累可能导致呼吸衰竭。
