Avaliação da hipernatremia

A hipernatremia é definida como uma concentração plasmática de sódio >145 mmol/L (145 mEq/L).

A hipernatremia é um estado de hiperosmolalidade, sendo, principalmente, um resultado do deficit de água ou, raramente, do ganho de sódio. Para manter o equilíbrio osmótico, o líquido intracelular (LIC) diminui de volume. As respostas adequadas são o aumento do consumo de água estimulado pela sede e a excreção da quantidade mínima de urina em concentração máxima.

Lactentes e adultos com comprometimento cognitivo são mais afetados devido à sua inabilidade de expressar sede e ao acesso limitado à água.

A hipernatremia é, frequentemente, resultado de vários processos patológicos, e a causa subjacente deve ser identificada para que se corrija o desequilíbrio de sódio. As consequências físicas da hipernatremia podem ser graves e sobreporem-se a várias das causas desencadeadoras.

Epidemiologia

A hipernatremia costuma ocorrer em pacientes em extremidades etárias ou nos que têm deficiência física ou cognitiva.[1]Brennan M, Mulkerrin L, O'Keeffe ST, et al. Approach to the management of hypernatraemia in older hospitalised patients. J Nutr Health Aging. 2021;25(10):1161-6. https://pmc.ncbi.nlm.nih.gov/articles/PMC12275548 http://www.ncbi.nlm.nih.gov/pubmed/34866143?tool=bestpractice.com [2]Molaschi M, Ponzetto M, Massaia M, et al. Hypernatremic dehydration in the elderly on admission to hospital. J Nutr Health Aging. 1997;1(3):156-60. http://www.ncbi.nlm.nih.gov/pubmed/10995084?tool=bestpractice.com [3]Tomkins M, Mc Donald D, Green D, et al. Diagnosis and treatment of hypernatremia. Best Pract Res Clin Endocrinol Metab. 2026 Jan;40(1):102065. http://www.ncbi.nlm.nih.gov/pubmed/41203493?tool=bestpractice.com

A hipernatremia adquirida no hospital é a forma mais comum de hipernatremia; em alguns casos é iatrogênica.[4]Tsipotis E, Price LL, Jaber BL, et al. Hospital-associated hypernatremia spectrum and clinical outcomes in an unselected cohort. Am J Med. 2018 Jan;131(1):72-82.e1. http://www.ncbi.nlm.nih.gov/pubmed/28860033?tool=bestpractice.com [5]Thongprayoon C, Cheungpasitporn W, Yap JQ, et al. Increased mortality risk associated with serum sodium variations and borderline hypo- and hypernatremia in hospitalized adults. Nephrol Dial Transplant. 2020 Oct 1;35(10):1746-52. https://academic.oup.com/ndt/article/35/10/1746/5521070 http://www.ncbi.nlm.nih.gov/pubmed/31219584?tool=bestpractice.com [6]Ranjan R, Lo SC, Ly S, et al. Progression to severe hypernatremia in hospitalized general medicine inpatients: an observational study of hospital-acquired hypernatremia. Medicina (Kaunas). 2020 Jul 17;56(7):358. https://www.mdpi.com/1648-9144/56/7/358 http://www.ncbi.nlm.nih.gov/pubmed/32709029?tool=bestpractice.com [7]Arzhan S, Roumelioti ME, Litvinovich I, et al. Hypernatremia in hospitalized patients: a large population-based study. Kidney360. 2022 Jul 28;3(7):1144-57. https://journals.lww.com/kidney360/Fulltext/2022/07000/Hypernatremia_in_Hospitalized_Patients__A_Large.8.aspx http://www.ncbi.nlm.nih.gov/pubmed/35919520?tool=bestpractice.com Dados de alta hospitalar de pacientes não selecionados sugerem que a hipernatremia adquirida no hospital pode se desenvolver em até 26% dos pacientes.[4]Tsipotis E, Price LL, Jaber BL, et al. Hospital-associated hypernatremia spectrum and clinical outcomes in an unselected cohort. Am J Med. 2018 Jan;131(1):72-82.e1. http://www.ncbi.nlm.nih.gov/pubmed/28860033?tool=bestpractice.com A hipernatremia presente na internação hospitalar é menos comum (por exemplo, de 3% a 21%).[4]Tsipotis E, Price LL, Jaber BL, et al. Hospital-associated hypernatremia spectrum and clinical outcomes in an unselected cohort. Am J Med. 2018 Jan;131(1):72-82.e1. http://www.ncbi.nlm.nih.gov/pubmed/28860033?tool=bestpractice.com [7]Arzhan S, Roumelioti ME, Litvinovich I, et al. Hypernatremia in hospitalized patients: a large population-based study. Kidney360. 2022 Jul 28;3(7):1144-57. https://journals.lww.com/kidney360/Fulltext/2022/07000/Hypernatremia_in_Hospitalized_Patients__A_Large.8.aspx http://www.ncbi.nlm.nih.gov/pubmed/35919520?tool=bestpractice.com

As taxas de mortalidade variam de 20% a 60% para todos os pacientes.[1]Brennan M, Mulkerrin L, O'Keeffe ST, et al. Approach to the management of hypernatraemia in older hospitalised patients. J Nutr Health Aging. 2021;25(10):1161-6. https://pmc.ncbi.nlm.nih.gov/articles/PMC12275548 http://www.ncbi.nlm.nih.gov/pubmed/34866143?tool=bestpractice.com [3]Tomkins M, Mc Donald D, Green D, et al. Diagnosis and treatment of hypernatremia. Best Pract Res Clin Endocrinol Metab. 2026 Jan;40(1):102065. http://www.ncbi.nlm.nih.gov/pubmed/41203493?tool=bestpractice.com [8]Muhsin SA, Mount DB. Diagnosis and treatment of hypernatremia. Best Pract Res Clin Endocrinol Metab. 2016 Mar;30(2):189-203. https://www.sciencedirect.com/science/article/abs/pii/S1521690X16000415?via%3Dihub http://www.ncbi.nlm.nih.gov/pubmed/27156758?tool=bestpractice.com A hipernatremia adquirida no hospital, a hipernatremia grave, o estado crítico da doença, a idade avançada e as comorbidades estão associadas a um prognóstico mais desfavorável.[1]Brennan M, Mulkerrin L, O'Keeffe ST, et al. Approach to the management of hypernatraemia in older hospitalised patients. J Nutr Health Aging. 2021;25(10):1161-6. https://pmc.ncbi.nlm.nih.gov/articles/PMC12275548 http://www.ncbi.nlm.nih.gov/pubmed/34866143?tool=bestpractice.com [4]Tsipotis E, Price LL, Jaber BL, et al. Hospital-associated hypernatremia spectrum and clinical outcomes in an unselected cohort. Am J Med. 2018 Jan;131(1):72-82.e1. http://www.ncbi.nlm.nih.gov/pubmed/28860033?tool=bestpractice.com [5]Thongprayoon C, Cheungpasitporn W, Yap JQ, et al. Increased mortality risk associated with serum sodium variations and borderline hypo- and hypernatremia in hospitalized adults. Nephrol Dial Transplant. 2020 Oct 1;35(10):1746-52. https://academic.oup.com/ndt/article/35/10/1746/5521070 http://www.ncbi.nlm.nih.gov/pubmed/31219584?tool=bestpractice.com [6]Ranjan R, Lo SC, Ly S, et al. Progression to severe hypernatremia in hospitalized general medicine inpatients: an observational study of hospital-acquired hypernatremia. Medicina (Kaunas). 2020 Jul 17;56(7):358. https://www.mdpi.com/1648-9144/56/7/358 http://www.ncbi.nlm.nih.gov/pubmed/32709029?tool=bestpractice.com [9]Thongprayoon C, Mao MA, Keddis MT, et al. Hypernatremia subgroups among hospitalized patients by machine learning consensus clustering with different patient survival. J Nephrol. 2022 Apr;35(3):921-9. http://www.ncbi.nlm.nih.gov/pubmed/34623631?tool=bestpractice.com [10]Yun G, Baek SH, Kim S. Evaluation and management of hypernatremia in adults: clinical perspectives. Korean J Intern Med. 2023 May;38(3):290-302. https://pmc.ncbi.nlm.nih.gov/articles/PMC10175862 http://www.ncbi.nlm.nih.gov/pubmed/36578134?tool=bestpractice.com

A hipernatremia é diagnosticada em igual número em homens e mulheres.