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. 2010;128(5):268-71.
doi: 10.1590/s1516-31802010000500005.

Evolution of blood magnesium and phosphorus ion levels following thyroidectomy and correlation with total calcium values

Alexandre de Andrade Sousa  1 , José Maria Porcaro Salles, João Marcos Arantes Soares, Gustavo Meyer de Moraes, Jomar Rezende Carvalho, Paulo Roberto Savassi-Rocha
Affiliations

Evolution of blood magnesium and phosphorus ion levels following thyroidectomy and correlation with total calcium values

Alexandre de Andrade Sousa et al. Sao Paulo Med J. 2010.

Abstract
in English, Portuguese

Context and objective: magnesium ion concentration is directly related and phosphorus ion concentration is inversely related to calcemia. The aim of this study was to evaluate the evolution of magnesium and phosphorus ion levels in patients undergoing thyroidectomy and correlate these with changes to calcium concentration.

Design and setting: prospective study at the Alpha Institute of Gastroenterology, Hospital das Clínicas, Universidade Federal de Minas Gerais.

Methods: the study included 333 patients, of both genders and mean age 45 ± 15 years, who underwent thyroidectomy between 2000 and 2005. Total calcium, phosphorus and magnesium were measured in the blood preoperatively and 24 and 48 hours postoperatively. Ionic changes were evaluated according to the presence or absence of postoperative hypocalcemia.

Results: there were statistically significant drops in blood phosphorus levels 24 and 48 hours after thyroidectomy, compared with preoperative values, in the patients without hypocalcemia. In the patients who developed hypocalcemia, there was a significant drop in plasma phosphorus on the first postoperative day and an increase (also statistically significant) on the second day, in relation to preoperative phosphorus levels. A significant drop in postoperative magnesium was also observed on the first and second days after thyroidectomy in the patients with hypocalcemia, in relation to preoperative levels. In the patients without hypocalcemia, the drop in magnesium was significant on the first day, but there was no difference on the second day.

Conclusion: despite the postoperative changes, neither magnesium nor phosphorus ion levels had any role in post-thyroidectomy calcemia.

CONTEXTO E OBJETIVO:: A concentração do íon magnésio está diretamente e a do íon fósforo inversamente relacionada à calcemia. O objetivo foi avaliar a evolução das concentrações dos íons magnésio e fósforo nos pacientes submetidos a tireoidectomia, e relacioná-los com as alterações da concentração do cálcio.

TIPO DE ESTUDO E LOCAL:: Estudo prospectivo realizado no Instituto Alfa de Gastroenterologia, Hospital das Clínicas, Universidade Federal de Minas Gerais.

MÉTODOS:: O estudo incluiu 333 pacientes de ambos os sexos, com média de idade de 45 ± 15 anos, submetidos a tireoidectomia no período de 2000 a 2005. Cálcio total, fósforo e magnésio foram dosados no pré-operatório e com 24 e 48 horas de pós-operatório. As alterações dos íons foram avaliadas de acordo com a presença ou ausência de hipocalcemia pós-operatória.

RESULTADOS:: Houve queda estatisticamente significativa dos níveis sanguíneos de fósforo 24 horas e 48 horas após a tireoidectomia em relação ao pré-operatório nos pacientes que não tiveram hipocalcemia. Quanto aos pacientes que evoluíram com hipocalcemia, houve queda significativa do fósforo plasmático no primeiro dia de pós-operatório e elevação, também estatisticamente significativa, no segundo dia em relação ao fósforo pré-operatório. Foi também observada queda significativa do magnésio pós-operatório em relação ao pré-operatório no primeiro e no segundo dia após a tireoidectomia nos pacientes com hipocalcemia. Naqueles sem hipocalcemia, a queda do magnésio foi significativa no primeiro dia, mas não houve diferença no segundo dia.

CONCLUSÃO:: Embora alterados no pós-operatório, as concentrações dos íons magnésio e fósforo não apresentaram papel na calcemia pós-tireoidectomia.

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Conflict of interest statement

Conflict of interest: Not declared

Figures

Figure 1.
Figure 1.. Mean total calcium, phosphorus and magnesium levels before the operation and on the first and second postoperative days (POD), among patients with hypocalcemia (A) and without hypocalcemia (B) after the surgery.
See this image and copyright information in PMC

References

    1. Arioli EL. Hipocalcemia [Hypocalcemia] Arq Bras Endocrinol Metab. 1999;43(6):467–471.
    1. Falk SA, Birken EA, Baran DT. Temporary postthyroidectomy hypocalcemia. Arch Otolaryngol Head Neck Surg. 1988;114(2):168–174. - PubMed
    1. Lemaire FX, Debruyne F, Delaere P, Vander Poorten V. Parathyroid function in the early postoperative period after thyroidectomy. Acta Otorhinolaryngol Belg. 2001;55(2):187–198. - PubMed
    1. Salles JMP, Soares JMA, Sousa AA, Salles PV. Prevenção e tratamento das complicações da tireoidectomia. In: Carvalho MB, editor. Tratado de tireóide e paratireóide. Rio de Janeiro: Rubio; 2007. pp. 651–662.
    1. International Ethical Guidelines for Biomedical Research Involving Human Subjects Geneva: Council for International Organizations of Medical Sciences (CIOMS) in collaboration with the World Health Organization (WHO) 2002 Available from: http://www.fhi.org/training/fr/retc/pdf_files/cioms.pdf. Accessed in 2010 (Sep 16) - PubMed