Possible association between dysnatremias and mortality during hospitalization in patients undergoing acute hemodialysis: analysis from a Peruvian retrospective cohort

Original Article | Artigo Original Possible association between dysnatremias and mortality during hospitalization in patients undergoing acute hemodialysis: analysis from a Peruvian retrospective cohort Possível associação entre distúrbios do sódio e mortalidade hospitalar em pacientes submetidos a hemodiálise aguda: análise de uma coorte retrospectiva peruana Authors Edward Mezones-Holguin1,2 Roberto Niño-Garcia2,3 Percy Herrera-Añazco 1,4 Álvaro Taype-Rondan1 Josmel Pacheco-Mendoza1 Adrian V. Hernandez1,5 Universidad San Ignacio de Loyola, Vicerrectorado de Investigación, Lima, Peru. 2 Epi-gnosis Solutions. Piura, Peru. 3 Universidad Nacional de Piura, Facultad de Ciencias de la Salud, Sociedad Científica de Estudiantes de Medicina de la Universidad Nacional de Piura (SOCIEMUNP), Piura, Peru. 4 Hospital Nacional 2 de mayo, Department of Nephrology, Lima, Peru. 5 University of Connecticut/ Hartford Hospital Evidence-based Practice Center, Hartford, CT, USA. 1 Submitted on: 11/29/2018. Approved on: 05/27/2019. Correspondence to: Edward Mezones-Holguín E-mail: DOI: 10.1590/2175-8239-JBN-2018-0243 Abstract Resumo Objective: To evaluate the association between dysnatremias or dyschloremias and mortality during hospitalization in patients with acute kidney injury (AKI) or chronic kidney disease (CKD) undergoing acute hemodialysis. Methods: We carried out a retrospective cohort study on adult patients undergoing acute hemodialysis with AKI or CKD diagnosis at a public hospital in Lima, Peru. Dysnatremias were categorized as hyponatremia (Na < 135mmol/L) or hypernatremia (Na > 145mmol/L), and dyschloremias were defined as hypochloremia (Cl < 98 mmol/L) or hyperchloremia (Cl > 109mmol/L). The outcome of interest was mortality during hospitalization. We performed generalized lineal Poisson family models with biascorrected and accelerated non-parametric bootstrap to estimate the risk ratios at crude (RR) and adjusted analysis (aRR) by gender, age, HCO3 (for all patients) and Liaño score (only for AKI) with CI95%. Results: We included 263 patients (mean age: 54.3 years, females: 43%): 191 with CKD and 72 with AKI. Mortality was higher in patients with AKI (59.7%) than in patients with CKD (14.1%). In overall, patients with hypernatremia had a higher mortality during hospitalization compared to those who had normal sodium values (aRR: 1.82, 95% CI: 1.17-2.83); patients with hyponatremia did not have different mortality (aRR: 0.19, 95% CI: 0.69-2.04). We also found that hyperchloremia (aRR: 1.35, 95% CI: 0.83-2.18) or hypochloremia (aRR: 0.66, 95% CI: 0.30-14.78) did not increase mortality in comparison to normal chloride values. No association between dysnatremias or dyschloremias and mortality during hospitalization was found in CKD and AKI subgroups. Conclusions: In our exploratory analysis, only hypernatremia was associated with mortality during hospitalization among patients with AKI or CKD undergoing acute hemodialysis. Objetivo: Avaliar a associação entre distúrbios do sódio ou do cloro e mortalidade hospitalar de pacientes com insuficiência renal aguda (IRA) ou doença renal crônica (DRC) submetidos a hemodiálise aguda. Métodos: O presente estudo de coorte retrospectiva incluiu pacientes adultos submetidos a hemodiálise aguda com diagnóstico de IRA ou DRC em um hospital público de Lima, Peru. Os distúrbios do sódio foram classificados como hiponatremia (Na < 135mmol/L) ou hipernatremia (Na > 145mmol/L), enquanto os distúrbios do cloro foram classificados como hipocloremia (Cl < 98 mmol/L) ou hipercloremia (Cl > 109mmol/L). O desfecho de interesse foi mortalidade hospitalar. Utilizamos modelos de Poisson da família de modelos lineares generalizados com bootstrap não-paramétrico e correção de viés acelerado para estimar os riscos relativos na análise bruta (RR) e ajustada (RRa) para sexo, idade, HCO3 (para todos os pacientes) e escore de Liaño (apenas para IRA) com IC 95%. Resultados: Foram incluídos 263 pacientes (idade média 54,3 anos; 43% do sexo feminino), 191 com DRC e 72 com IRA. A mortalidade foi mais elevada nos pacientes com IRA (59,7%) do que nos indivíduos com DRC (14,1%). No geral, os pacientes com hipernatremia tiveram mortalidade hospitalar mais elevada do que os indivíduos com valores normais de sódio (RRa: 1,82; IC 95%: 1,17-2,83). Os pacientes com hiponatremia não apresentaram mortalidade diferente (RRa: 0,19; IC 95%: 0,69-2,04). Também identificamos que hipercloremia (RRa: 1,35; IC 95%: 0,832,18) e hipocloremia (RRa: 0,66; IC 95%: 0,30-14,78) não elevaram a mortalidade em comparação a indivíduos com níveis normais de cloro. Não foi encontrada associação entre distúrbios do sódio ou do cloro e mortalidade hospitalar nos subgrupos com DRC e IRA. Conclusões: Em nossa análise exploratória, apenas hipernatremia apresentou associação com mortalidade hospitalar em pacientes com IRA ou DRC submetidos a hemodiálise aguda. 501 Dysnatremias and mortality in acute hemodialysis Keywords: Acute renal injury; Renal Insufficiency, Chronic; Dialysis; Chlorine; Sodium; Mortality. Palavras-chave: Lesão Renal Aguda; Insuficiência Renal Crônica; Diálise; Cloro; Sódio; Mortalidade. Introduction acute hemodialysis at the Nephrology Department of National Hospital 2 de Mayo, a public general hospital of Ministry of Health located in Lima, Peru, between January 2015 and July 2017. AKI or CKD diagnosis, as well as the indication for hemodialysis, were determined by an attending nephrologist based on clinical criteria proposed in the Kidney Disease Improving Global Outcomes (KDIGO) guidelines24. We excluded patients admitted to dialysis without kidney disease (vg. methanol intoxication, etc.) and patients who had received dialysis in other hospitals (since we could not access to the laboratory results and clinical evaluation before initiating the hemodialysis). Acute hemodialysis was defined as the emergency dialysis in a patient who never have received dialysis before. Both groups of patients (AKI and CKD) had conventional hemodialysis. In average, they had three sessions per week with a duration of 3.5-4 hours, using low-flow biocompatible synthetic membranes (polysulfone). Electrolytes and their alterations have an important repercussion in health, and it supposed to be an important challenge in clinical practice. These molecules contribute to maintaining human body homeostasis1. Chloride (Cl) and sodium (Na) and their alterations - called dyschloremias and dysnatremias, respectively - have been associated with several harmful events in acute and chronic clinical situations2–12. Patients with kidney diseases are a special population of interest. These patients are more likely to have alterations of Na and Cl, and to produce deleterious effects on their health. These include changes of urine dilution and concentration in response to antidiuretic hormone, and alteration of water and Na and CI reabsorption and excretion13,14. Previous studies have reported that dysn (...truncated)