Kidney International (2006) 70
© 2006 International Society of Nephrology
Kidney International (2006) 70, 1197. doi:10.1038/sj.ki.5001693
Tetany during bicarbonate loading test
M-Y Lai1,2, C-L Chuang1,2, C-C Lin1,2, Y-Y Ng1,2 and W-C Yang1,2
1Division of Nephrology, Taipei Veterans General Hospital, Taipei, Taiwan; and 2School of Medicine, National Yang-Ming University, Taipei, Taiwan
Correspondence: M-Y Lai, Division of Nephrology, Taipei Veterans General Hospital, No. 201, Sec. 2, Shih-Pai Road, Taipei 11217, Taiwan.
A 41-year-old woman presented with hypokalemic paralysis with
non-anion-gap metabolic acidosis and normotension. During the
work-up of suspected renal tubular acidosis, a bicarbonate loading
test was performed. During the test, the patient developed tetany
with severe facial (Figure 1) and carpal spasm (Figure 2). Her
venous pH at this time was 7.47 (venous bicarbonate 26 mequiv.
per liter) from a baseline of 7.31 (venous bicarbonate 12.2 mequiv.
per liter). Th e infusion was discontinued, and calcium gluconate
(9.2 mequiv.) was administered intravenously with complete sub-
sidence of symptoms. Th e serum ionized calcium level at this event
was 0.68 mmol per liter, and the baseline serum total calcium level
was 7.8 mg per dl with serum albumin of 3.5 g per dl. Rapid alkali-
zation of plasma may induce acute hypocalcemia leading to tetany;
other complications in this setting can include seizures, cardiac
dysrhythmias (prolongation of the QT interval), decreased cardiac
contractility, hypotension, and heart failure.
Figure 1 | Severe facial spasm made it difficult for this patient to open
her mouth or speak during the bicarbonate loading test.
Figure 2 | Severe bilateral carpal spasm during the bicarbonate