Daggett P, Deanfield J, Moss F
Postgrad Med J. 1982 Dec;58(686):737-40. doi: 10.1136/pgmj.58.686.737.
Hyponatraemia is a common biochemical finding, but clinical features due to it are infrequent. They are most likely to occur when the plasma sodium concentration has fallen quickly to below 120 mmol/litre. In a study of 73 hyponatraemic individuals, it was possible to identify four categories of patient, the clinical features becoming more severe as the sodium level fell. In 25 instances there were no effects (mean plasma sodium 118·3 mmol/litre), in a further 25 cases there was confusion only (mean plasma sodium 117·1 mmol/litre), in 13 there were focal neurological signs and in 10 there were convulsions (mean plasma sodium 110·8 mmol/litre). In the group with convulsions there were six deaths, the four survivors all being young women. The 13 cases of ‘focal’ neurological signs included three instances each of hemiparesis and monoparesis, seven of extra-pyramidal disturbance and six of cerebellar ataxia. All these abnormalities resolved when the plasma sodium concentration rose to 125 mmol/litre. Active measures to raise the plasma sodium level are only needed when there have been convulsions and the aim should be to achieve a value no higher than 120 mmol/litre. In other cases, the only treatment required is to restrict fluid intake.
低钠血症是一种常见的生化检查结果，但由此引起的临床症状并不常见。当血浆钠浓度迅速降至120 mmol/升以下时，最有可能出现临床症状。在一项对73名低钠血症患者的研究中，确定了四类患者，随着钠水平的下降，临床症状变得更加严重。25例患者没有症状（平均血浆钠浓度为118.3 mmol/升），另外25例仅有意识模糊（平均血浆钠浓度为117.1 mmol/升），13例有局灶性神经体征，10例有惊厥（平均血浆钠浓度为110.8 mmol/升）。在有惊厥的患者组中有6例死亡，4名幸存者均为年轻女性。13例“局灶性”神经体征包括偏瘫和单瘫各3例、锥体外系障碍7例和小脑共济失调6例。当血浆钠浓度升至125 mmol/升时，所有这些异常均消失。只有在出现惊厥时才需要采取积极措施提高血浆钠水平，目标应是使血浆钠浓度不高于120 mmol/升。在其他情况下，唯一需要的治疗是限制液体摄入。
