Cross-sectional study of the association between functional status and acute kidney injury in geriatric patients

BACKGROUND

Patients with chronic kidney disease tend to have impaired functional status, and this can increase the risk of morbidity and mortality. However, no previous studies have rigorously evaluated the relationship between incident acute kidney injury (AKI) and functional status of elderly patients.

METHODS

Elderly patients (≥ 65 years-old) were prospectively from the general medical wards of a single medical center in Taiwan between January, 2014 and August, 2014. These patients were divided into those with and without AKI at initial presentation, according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. Functional status was assessed by Barthel Index on admission. Multiple regression analyses were utilized to investigate the relationship between AKI and functional status.

RESULTS

One hundred and fifty-two elderly patients were recruited, 38.9 % of whom had AKI. Patients with AKI at admission had significantly higher mean Charlson Comorbidity Index score (p = 0.05) and borderline lower mean Barthel Index score (34.5 vs. 43.1; p = 0.08), and a significantly lower bladder continence subscale (5.4 vs. 7.0; p = 0.05). Multiple regression analyses indicated that the presence of AKI at admission was associated with a significantly lower Barthel Index score (p = 0.04). Increasing AKI severity (higher KDIGO stage) was also associated with significantly lower Barthel Index score (p < 0.01).

CONCLUSIONS

This study documented a close relationship between AKI and functional status in the elderly. Interventions that aim to restore functional status might help to lower the risk of AKI in the elderly.

Association of serum bicarbonate with incident functional limitation in older adults

BACKGROUND AND OBJECTIVES

Cross-sectional studies have found that low serum bicarbonate is associated with slower gait speed. Whether bicarbonate levels independently predict the development of functional limitation has not been previously studied. Whether bicarbonate was associated with incident persistent lower extremity functional limitation and whether the relationship differed in individuals with and without CKD were assessed in participants in the Health, Aging, and Body Composition study, a prospective study of well functioning older individuals

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Functional limitation was defined as difficulty in walking 0.25 miles or up 10 stairs on two consecutive reports 6 months apart in the same activity (stairs or walking). Kidney function was measured using eGFR by the Chronic Kidney Disease Epidemiology Collaboration creatinine equation, and CKD was defined as an eGFR<60 ml/min per 1.73 m(2). Serum bicarbonate was measured using arterialized venous blood gas. Cox proportional hazards analysis was used to assess the association of bicarbonate (<23, 23-25.9, and ≥26 mEq/L) with functional limitation. Mixed model linear regression was performed to assess the association of serum bicarbonate on change in gait speed over time.

RESULTS

Of 1544 participants, 412 participants developed incident persistent functional limitation events over a median 4.4 years (interquartile range, 3.1 to 4.5). Compared with ≥26 mEq/L, lower serum bicarbonate was associated with functional limitation. After adjustment for demographics, CKD, diabetes, body mass index, smoking, diuretic use, and gait speed, lower serum bicarbonate was significantly associated with functional limitation (hazard ratio, 1.35; 95% confidence interval, 1.08 to 1.68 and hazard ratio, 1.58; 95% confidence interval, 1.12 to 2.22 for bicarbonate levels from 23 to 25.9 and <23, respectively). There was not a significant interaction of bicarbonate with CKD. In addition, bicarbonate was not significantly associated with change in gait speed.

CONCLUSIONS

Lower serum bicarbonate was associated with greater risk of incident, persistent functional limitation. This association was present in individuals with and without CKD.

Current and emerging treatment options for the elderly patient with chronic kidney disease

The objective of this article is to review the current and emerging treatments of CKD prior to dialysis in the elderly. Worldwide, there are increasing numbers of people who are aged over 65 years. In parallel, there are increasing numbers of elderly patients presenting with chronic kidney disease (CKD), particularly in the more advanced stages. The elderly have quite different health care needs related to their associated comorbidity, frailty, social isolation, poor functional status, and cognitive decline. Clinical trials assessing treatments for CKD have usually excluded patients older than 70–75 years; therefore, it is difficult to translate current therapies recommended for younger patients with CKD across to the elderly. Many elderly people with CKD progress to end-stage kidney disease and face the dilemma of whether to undertake dialysis or accept a conservative approach supported by palliative care. This places pressure on the patient, their family, and on health care resources. The clinical trajectory of elderly CKD patients has in the past been unclear, but recent evidence suggests that many patients over 75 years of age with multiple comorbidities have greatly reduced life expectancies and quality of life, even if they choose dialysis treatment. Offering a conservative pathway supported by palliative care is a reasonable option for some patients under these circumstances. The elderly person who chooses to have dialysis will frequently have different requirements than younger patients. Kidney transplantation can still result in improved life expectancy and quality of life in the elderly, in carefully selected people. There is a genuine need for the inclusion of the elderly in CKD clinical trials in the future so we can produce evidence-based therapies for this group. In addition, new therapies to treat and slow CKD progression are needed for all age groups.

Outcomes in older adults with stage 5 chronic kidney disease: comparison of peritoneal dialysis and conservative management

BACKGROUND

Data on the outcomes of older adults receiving peritoneal dialysis (PD), especially those who are dependent and have multiple comorbidities, are scarce.

METHODS

In a retrospective cohort study, we compared older adults (≥65 years) with stage 5 chronic kidney disease receiving PD (PD group) with those receiving conservative management (conservative group). Baseline characteristics (demographics and clinical, functional, socioeconomic, and laboratory parameters) were collected, and study outcomes (patient survival, emergency hospitalization, institutionalization, and palliative and end-of-life care) were compared between groups.

RESULTS

We included 199 eligible participants aged 65-90 years (mean ± standard deviation 73.8 ± 5.4 years; 157 in the PD group and 42 in the conservative group). The PD group had a longer survival (median [interquartile range]: 3.75 [2.49-5.25] vs 2.35 [1.13-3.71] years, p < .001), lower emergency hospitalization rates (1.63 [0.82-2.92] vs 3.51 [1.06-7.16] per person-year, p < .01) and hospital days (16.17 [6.29-43.32] vs 38.01 [6.75-76.56] days per person-year, p = .03), and no increased risk of institutionalization compared with the conservative group. Age (hazard ratio [HR] for 1-year increase 1.06, 95% confidence interval [CI] 1.02-1.10), modified Charlson's Comorbidity Index (HR 1.36, 95% CI 1.18-1.56), impairment in basic activities of daily living (HR 2.11, 95% CI 1.28-3.46), and emergency dialysis (HR 1.67, 95% CI 1.11-2.53) were independent predictors of mortality in the PD group.

CONCLUSION

PD is a viable treatment option in older adults with stage 5 chronic kidney disease. Age alone should not preclude dialysis. Comprehensive geriatric assessment can prognosticate and facilitate shared decision making to commence dialysis in older adults.