Impact of hyponatremia and the syndrome of inappropriate antidiuresis on mortality in elderly patients with aspiration pneumonia

Abstract

BACKGROUND:Hyponatremia is associated with pneumonia, and aspiration pneumonia is common in the elderly, however, there has been no study of hyponatremia in this population.OBJECTIVE:To determine the impact of hyponatremia on mortality in elderly patients with aspiration pneumonia, while focusing on the comparison between those with and without the syndrome of inappropriate antidiuresis (SIAD).DESIGN:Retrospective review of existing database and medical records.SETTING:A community teaching hospital in Japan.PATIENTS:Two hundred and twenty‐one elderly patients hospitalized with aspiration pneumonia.MEASUREMENTS:Multivariate logistical regression models were used to compare 30‐day and in‐hospital mortality, in patients with hyponatremia of various severities and etiologies, with that in patients with normal serum sodium concentrations.RESULTS:Sixty‐five (29%) of 221 patients had hyponatremia. Of these 62 (95%) had hypotonic hyponatremia, which were further assessed as having hypovolemic (39 [63%]), hypervolemic (3 [5%]), and euvolemic (20 [32%]) hyponatremia. Of the 20 euvolemic patients, 14 (70%) had SIAD. Both moderate and severe hypotonic hyponatremia were significantly associated with increased in‐hospital mortality (odds ratio [OR] 6.05, 95% confidence interval [CI] 1.46–25.0, and OR 5.65, 95% CI 1.14–28.1, respectively). Hyponatremia due to SIAD was significantly associated with both increased 30‐day mortality (OR 7.40, 95% CI 1.73–31.7) and increased in‐hospital mortality (OR 22.3, 95% CI 4.26–117). In contrast, hypovolemic hyponatremia was not significantly associated with increased mortality.CONCLUSIONS:Hyponatremia due to SIAD was strongly associated with increased mortality in elderly patients with aspiration pneumonia, whereas hypovolemic hyponatremia was not associated with increased mortality. Journal of Hospital Medicine 2012;. © 2012 Society of Hospital Medicine

Hyponatraemia in patients with community‐acquired pneumonia; prevalence and aetiology, and natural history of SIAD

“…Our study, which was designed to define the volaemic causation of hyponatraemia, was underpowered to compare mortality with eunatraemic pneumonia. However, we observed a trend towards higher mortality in patients with CAP and hyponatraemia when compared to eunatraemic controls, in line with previous observations …”

“…Hyponatraemia occurs in 8%‐31% of adult patients with CAP with higher incidence in children (27%‐45%) and Legionella pneumonia(44%) . Hyponatraemia in CAP is usually mild (130‐134 mmol/L) and asymptomatic, yet epidemiological data consistently demonstrate increased mortality, more frequent ITU admission, and prolonged hospital stay, in patients with CAP and hyponatraemia. Consequently, hyponatraemia in CAP has been associated with an increase in hospital costs …”

“…Treatment of hyponatraemia is aetiology dependent, but as the causation of hyponatraemia in CAP is uncertain, management strategies cannot be defined. Studies in children have suggested that most hyponatraemia in CAP is secondary to SIAD, whereas a retrospective analysis of elderly patients found that 63% had hypovolaemic hyponatraemia and only 22% had SIAD . Other studies have suggested that SIAD is the commonest underlying mechanism .…”

In Nonagenarians, Acute Kidney Injury Predicts In-Hospital Mortality, while Heart Failure Predicts Hospital Length of Stay

“…Main admission diagnoses of nephrologic diseases in geriatrics consists of the diagnosis and management of acute/chronic renal dysfunction, UTI (upper/lower), and dyselectrolytemia. Each of these components helps determine the hospitalization outcomes in the old: dysnatremia and dyskalemia at elderly admission is associated with in-hospital mortality [43], [44], while UTI contributes to higher morbidity and mortality in the institutionalized old [45]. Furthermore, older patients have more limited renal reserve and are prone to develop AKI [46], [47].…”

A severe H7N9 pneumonia with syndrome of inappropriate antidiuresis and vitamin D deficiency

“…Some studies suggested that both SIAD and hyponatremia had negative impact in elderly patients with pneumonia. Miyashita and colleagues reported that mortality in elderly patients with aspiration pneumonia was significantly associated with SIAD [7]. A study by Nair and colleagues reported some increased risk of death with hyponatremia [8].…”