Journal of Clinical and Scientific Research

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 9  |  Issue : 3  |  Page : 160--163

Study of electrolyte patterns in elderly admitted with infection


Maneesha Regati, Priya Vijayakumar 
 Department of Geriatric Medicine, Amrita Institute of Medical Sciences, Kochi, Kerala, India

Correspondence Address:
Priya Vijayakumar
Professor, Department of Geriatric Medicine, Amrita Institute of Medical Sciences, Kochi 682 041, Kerala
India

Abstract

Background: Sparse published data are available regarding electrolyte abnormalities in elderly patients admitted to hospital with infection. Methods: We retrospectively studied the case records of 115 elderly patients (aged >60 years) admitted with 131 episodes of admissions due to various infections to the geriatric medicine wards and intensive care unit in our tertiary care teaching hospital during January 2018– September 2019. Results: Their mean age (years) was 79.1 ± 8.2 years; there were 58 (50.4%) females. Seven patients were admitted twice; one patient was admitted thrice with infection. The common sites of infection were lower respiratory tract (n = 58, 44.3%); urinary tract (n = 56, 42.7%); cellulitis, wound and soft-tissue infections (n = 22, 16.8%); and sepsis and related syndromes (n = 11, 8.4%). The common comorbid conditions included hypertension (67.8%), diabetes mellitus (45.2%), coronary artery disease (26.1%) and chronic kidney disease (12.2%). Hyponatraemia was the most common electrolyte abnormality seen in 53/131 (40.5%) episodes followed by hypocalcaemia (35/112, 31.2%), hypokalaemia (22/131, 16.8%), hypernatraemia (n = 1), hyperkalaemia (n = 9), hypercalcaemia (n = 2), hypomagnesaemia (n = 15), hypophosphataemia (n = 11) and hyperphosphataemia (n = 3). All patients with dyselectrolytaemia were receiving multiple (median [interquartile range (IQR)] 6 [3.75–8]) drugs. The median (IQR) duration of hospital stay was 6 (4–10) days. Eight of the 115 (7%) patients died; four of these eight patients had been admitted more than once with infection. There was no statistically significant difference in the proportion of patients with hyponatraemia (65/108 vs. 3/8; P = NS) and hypokalaemia (8/108 vs. 1/8; P = NS) among survivors and non-survivors. Conclusions: Dyselectrolytaemia is a common correctable metabolic abnormality seen in elderly patients hospitalised with infections. Careful monitoring and instituting correction can be life-saving.



How to cite this article:
Regati M, Vijayakumar P. Study of electrolyte patterns in elderly admitted with infection.J Clin Sci Res 2020;9:160-163


How to cite this URL:
Regati M, Vijayakumar P. Study of electrolyte patterns in elderly admitted with infection. J Clin Sci Res [serial online] 2020 [cited 2021 Jan 21 ];9:160-163
Available from: https://www.jcsr.co.in/text.asp?2020/9/3/160/298956


Full Text



 Introduction



Normal physiological changes of ageing increase the likelihood of electrolyte disorders in the elderly. Under normal conditions, the elderly can maintain electrolyte balance.[1],[2] This may be jeopardised by an illness and with certain medications, making them more susceptible to dyselectrolytaemia. Therefore, it is important to identify electrolyte abnormalities, which may develop in admitted elderly patients, in order to prevent adverse outcomes.

Sparse published data are available regarding electrolyte abnormalities in elderly patients admitted to hospital with infection. This study was conducted to document the proportion of patients with dyselectrolytaemia among elderly patients admitted with various infections to geriatric medicine service and study the association with in-hospital mortality.

 Material and Methods



We retrospectively studied the case records of elderly patients (aged >60 years) admitted with infection in the department of geriatric medicine during the period of January 2018 to September 2019. The study was approved by the institutional ethics committee.

Published data[3] suggest that 20% of hospitalised patients with pneumonia have hyponatraemia. Extrapolating these data to elderly patients requiring hospitalisation to ward and intensive care units, it is likely that 30% of the elderly patients admitted to hospital with infection manifest dyselectrolytaemia. With a precision of 0.08 and a desired confidence level of 95%, the required sample size was calculated to be 126. Sample size calculations were done using nMaster® software (Version 2) (Copyright© Department of Biostatistics, CMC, Vellore, Tamil Nadu, India).

A detailed history of all the admitted patients was taken, and a thorough physical examination was carried out. Details regarding comorbid conditions were noted. Blood culture and appropriate body fluid cultures were submitted for bacteriologic testing to identify the aetiological agent. Initially, empirical antibiotic treatment was initiated as per the institute's antibiotic policy. On availability of bacterial culture and sensitivity report, the antibiotic therapy was appropriately modified. All patients were followed up till in-hospital death, or discharge.

The following data were recorded in a pre-designed structured pro forma: demographic data (age and gender), duration of hospital stay, comorbid conditions, site of infection, treatment details, serum electrolytes (sodium, potassium, calcium, magnesium and phosphorus) and data regarding outcome (alive/dead).

Statistical analysis

Continuous variables were summarised as mean ± standard deviation and median (interquartile range). Categorical variables were summarised as percentages. Continuous variables were compared using Student's t-test and Mann–Whitney U-test. Categorical variables were compared using Chi-square test and Fisher's exact test as appropriate. A two-tailed P < 0.05 was considered statistically significant. The statistical software IBM SPSS Statistics Version 20 (IBM Corp Somers, NY, USA) was used for statistical analysis.

 Results



We retrospectively studied the case records of 115 elderly patients (aged >60 years) admitted with 131 episodes of admissions due to various infections to the geriatric medicine wards and intensive care unit in our tertiary care teaching hospital during the period of January 2018– September 2019.

Their mean age (years) was 79.1 ± 8.2 years. There were 58 (50.4%) females. The common comorbid conditions included systemic hypertension (67.8%), Type 2 diabetes mellitus (45.2%), coronary artery disease (26.1%) and chronic kidney disease (12.2%). Seven patients were admitted twice; one patient was admitted thrice with infection. The common sites of infection are shown in [Table 1]. The common sites of infection included lower respiratory tract (n = 58, 44.3%) and urinary tract (n = 56, 42.7%) [Table 1].{Table 1}

The common electrolyte abnormalities that were observed are shown in [Table 2]. Hyponatraemia was the most common electrolyte abnormality seen in 53/131 (40.5%) episodes followed by hypocalcaemia (35/112, 31.2%) and hypokalaemia (22/131, 16.8%).{Table 2}

All patients with dyselectrolytaemia were receiving multiple (median [interquartile range (IQR)] 6 [3.75–8]) drugs. The median (IQR) duration of hospital stay was 6 (4–10) days. Eight of the 115 (7%) patients died; four of these eight patients had been admitted more than once with infection. There was no statistically significant difference in the proportion of patients with hyponatraemia (65/108 vs. 3/8; P = NS) and hypokalaemia (8/108 vs. 1/8; P = NS) among survivors and non-survivors.

 Discussion



World over, elderly population is on the rise.[4] Compared with 11% in 2000, the proportion of elderly population (aged >60 years) is expected to double (22%) by 2050.[5] By 2021, the proportion of the elderly (>60 years) is expected to increase to 10.7%.[6],[7] Electrolyte disturbances are commonly encountered in older patients and may be life-threatening.[8] In elderly patients admitted with infection, electrolyte abnormalities can be the consequence of infection and contribute to mortality.[9]

Dysnatraemias are common electrolyte abnormalities in the elderly patients and the known causes are numerous.[3],[10],[11],[12] In our study, hyponatraemia (40.5%) was the most frequently encountered dyselectrolytaemia. In other published studies also, hyponatraemia was documented to be the most common electrolyte abnormality in elderly patients. The elderly are more prone to develop hyponatraemia, and the aetiology of hyponatraemia in the elderly is thought to be multifactorial. Various hypotheses, such as ageing-related impaired water-excretory capacity and reduction in the percentage of total body water content; comorbid conditions and medications administered to treat these and diseases associated with hyponatraemia are thought to be the causes.[13],[14],[15]

Pseudohyponatraemia is observed in patients with hyperproteinaemia (as seen in multiple myeloma and other monoclonal gammopathies or with intravenous immunoglobulin administration) and severe hyperlipidaemia (hypertriglyceridaemia and hypercholesterolaemia).[14] The opposite phenomenon of spurious higher serum sodium levels (pseudohypernatraemia, pseudonormonatraemia in the cases of true normo/or hyponatraemia, respectively) may also occur when sodium is measured with methods requiring a pre-dilution step, as a result of severe hypoproteinaemia that is not infrequently observed in the elderly.

Several patients in the present study manifested abnormalities of potassium, calcium, phosphorus and magnesium [Table 2]. Of these, hypocalcaemia (16.8%), hypokalaemia (16.8%) and hypomagnesaemia (14.4%) were the most common abnormalities encountered. Whether these were the consequence of the infection or whether these were due to the associated comorbid conditions is difficult to distinguish.[2],[16],[17] Majority of the time, the plasma electrolytes are normal in the healthy elderly population unless there is undue stress. Sparse published data are available regarding abnormalities in the homeostasis of potassium, phosphorous or magnesium in elderly patients admitted with infection and their bearing on clinical outcomes. There is a need to further study the clinical relevance of these abnormalities.

The present study raises concern regarding the prognostic significance of electrolyte abnormalities in elderly patients admitted with infection. Prospective studies adequately powered to answer this research question are warranted. Dyselectrolytaemia is a common correctable metabolic abnormality seen in elderly patients hospitalised with infections and is an important cause of morbidity. Careful monitoring and instituting correction can be life-saving.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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