Dehydration and clinical outcome in hospitalised older adults: A cohort study

Population incidence and associated mortality of urinary tract infection in people living with dementia

OBJECTIVES

Urinary tract infections (UTIs) frequently cause hospitalisation and death in people living with dementia (PLWD). We examine UTI incidence and associated mortality among PLWD relative to matched controls and people with diabetes and investigate whether delayed or withheld treatment further impacts mortality.

METHODS

Data were extracted for n = 2,449,814 people aged ≥ 50 in Wales from 2000-2021, with groups matched by age, sex, and multimorbidity. Poisson regression was used to estimate incidences of UTI and mortality. Cox regression was used to study the effects of treatment timing.

RESULTS

UTIs in dementia (HR=2.18, 95 %CI [1.88-2.53], p < .0) and diabetes (1.21[1.01-1.45], p = .035) were associated with high mortality, with the highest risk in individuals with diabetes and dementia (both) (2.83[2.40-3.34], p < .0) compared to matched individuals with neither dementia nor diabetes. 5.4 % of untreated PLWD died within 60 days of GP diagnosis-increasing to 5.9 % in PLWD with diabetes.

CONCLUSIONS

Incidences of UTI and associated mortality are high in PLWD, especially in those with diabetes and dementia. Delayed treatment for UTI is further associated with high mortality.

Determining pre-procedure fasting alert time using procedural and scheduling data

Before a medical procedure requiring anesthesia, patients are required to not eat or drink non-clear fluids for 6 h and not drink clear fluids for 2 h. Fasting durations in standard practice far exceed these minimum thresholds due to uncertainties in procedure start time. The aim of this retrospective, observational study was to compare fasting durations arising from standard practice with different approaches for calculating the timepoint at which patients are instructed to stop eating and drinking. Scheduling data for procedures performed in the cardiac catheterization laboratory of an academic hospital in Canada (January 2020 to April 2022) were used. Four approaches utilizing machine learning (ML) and simulation were used to predict procedure start times and calculate when patients should be instructed to start fasting. Median fasting duration for standard practice was 10.08 h (IQR 3.5) for both food and clear fluids intake. The best performing alternative approach, using tree-based ML models to predict procedure start time, reduced median fasting from food/non-clear fluids to 7.7 h (IQR 2) and clear liquids fasting to 3.7 h (IQR 2.4). 97.3% met the minimum fasting duration requirements (95% CI 96.9% to 97.6%). Further studies are required to determine the effectiveness of operationalizing this approach as an automated fasting alert system.

A comparison of the NIRUDAK models and WHO algorithm for dehydration assessment in older children and adults with acute diarrhoea: a prospective, observational study

BACKGROUND

Despite the importance of accurate and rapid assessment of hydration status in patients with acute diarrhoea, no validated tools exist to help clinicians assess dehydration severity in older children and adults. The aim of this study is to validate a clinical decision support tool (CDST) and a simplified score for dehydration severity in older children and adults with acute diarrhoea (both developed during the NIRUDAK study) and compare their accuracy and reliability with current WHO guidelines.

METHODS

A random sample of patients aged 5 years or older presenting with diarrhoea to the icddr,b Dhaka Hospital in Bangladesh between Jan 30 and Dec 13, 2022 were included in this prospective cohort study. Patients with fewer than three loose stools per day, more than 7 days of symptoms, previous enrolment in the study, or a diagnosis other than acute gastroenteritis were excluded. Patients were weighed on arrival and assessed separately by two nurses using both our novel clinical tools and WHO guidelines. Patients were weighed every 4 h to determine their percent weight change with rehydration, our criterion standard for dehydration. Accuracy for the diagnosis of dehydration category (none, some, or severe) was assessed using the ordinal c-index (ORC). Reliability was assessed by comparing the prediction of severe dehydration from each nurse's independent assessment using the intraclass correlation coefficient (ICC).

FINDINGS

1580 patients were included in our primary analysis, of whom 921 (58·3%) were female and 659 (41·7%) male. The ORC was 0·74 (95% CI 0·71-0·77) for the CDST, 0·75 (0·71-0·78) for the simplified score, and 0·64 (0·61-0·67) for the WHO guidelines. The ICC was 0·98 (95% CI 0·97-0·98) for the CDST, 0·94 (0·93-0·95) for the simplified score, and 0·56 (0·52-0·60) for the WHO guidelines.

INTERPRETATION

Use of our CDST or simplified score by clinicians could reduce undertreatment and overtreatment of older children and adults with acute diarrhoea, potentially reducing morbidity and mortality for this common disease.

FUNDING

US National Institutes of Health.

TRANSLATION

For the Bangla translation of the abstract see Supplementary Materials section.

The 2023 Sir David Cuthbertson Lecture. A fluid journey: Experiments that influenced clinical practice

This review summarises some of my work on fluid and electrolyte balance over the past 25 years and shows how the studies have influenced clinical practice. Missing pieces in the jigsaw are filled in by summarising the work of others. The main theme is the biochemical, physiological and clinical problems caused by inappropriate use of saline solutions including the hyperchloraemic acidosis caused by 0.9% saline. The importance of accurate and near-zero fluid balance in clinical practice is also emphasised. Perioperative fluid and electrolyte therapy has important effects on clinical outcome in a U-shaped dose response fashion, in which excess or deficit progressively increases complications and worsens outcome. Salt and water overload, with weight gain in excess of 2.5 kg worsens surgical outcome, impairs gastrointestinal function and increases the risk of anastomotic dehiscence. Hyperchloraemic acidosis caused by overenthusiastic infusion of 0.9% saline leads to adverse outcomes and dysfunction of many organ systems, especially the kidney. Salt and water deficit causes similar adverse effects as fluid overload at the cellular level and also leads to worse outcomes. Serum albumin is shown to be affected mainly by dilution and inflammation and is not a good nutritional marker. These findings have been incorporated in the British consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients (GIFTASUP) and National Institute for Health and Care Excellence (NICE) guidelines on intravenous fluid therapy in adults in hospital and are helping change clinical practice and improve outcomes.

Low-intake dehydration prevalence in non-hospitalised older adults: Systematic review and meta-analysis

BACKGROUND & AIMS

Low-intake dehydration amongst older people, caused by insufficient fluid intake, is associated with mortality, multiple long-term health conditions and hospitalisation. The prevalence of low-intake dehydration in older adults, and which groups are most at-risk, is unclear. We conducted a high-quality systematic review and meta-analysis, implementing an innovative methodology, to establish the prevalence of low-intake dehydration in older people (PROSPERO registration: CRD42021241252).

METHOD

We systematically searched Medline (Ovid), Cochrane CENTRAL, Embase (Ovid), CINAHL and Proquest from inception until April 2023 and Nutrition and Food Sciences until March 2021. We included studies that assessed hydration status for non-hospitalised participants aged ≥65 years, by directly-measured serum/plasma osmolality, calculated serum/plasma osmolarity and/or 24-h oral fluid intake. Inclusion, data extraction and risk of bias assessment was carried out independently in duplicate.

RESULTS

From 11,077 titles and abstracts, we included 61 (22,398 participants), including 44 in quality-effects meta-analysis. Meta-analysis suggested that 24% (95% CI: 0.07, 0.46) of older people were dehydrated (assessed using directly-measured osmolality >300 mOsm/kg, the most reliable measure). Subgroup analyses indicated that both long-term care residents (34%, 95% CI: 0.09, 0.61) and community-dwelling older adults (19%, 95% CI: 0.00, 0.48) were highly likely to be dehydrated. Those with more pre-existing illnesses (37%, 95% CI: 0.14, 0.62) had higher low-intake dehydration prevalence than others (15%, 95% CI: 0.00, 0.43), and there was a non-significant suggestion that those with renal impairment (42%, 95% CI: 0.23, 0.61) were more likely to be dehydrated than others (23%, 95% CI: 0.03, 0.47), but there were no clear differences in prevalence by age, sex, functional, cognitive or diabetic status. GRADE quality of evidence was low as to the exact prevalence due to high levels of heterogeneity between studies.

CONCLUSION

Quality-effects meta-analysis estimated that a quarter of non-hospitalised older people were dehydrated. Widely varying prevalence rates in individual studies, from both long-term care and community groups, highlight that dehydration is preventable amongst older people.

IMPLICATIONS

One in every 4 older adults has low-intake dehydration. As dehydration is serious and prevalent, research is needed to better understand drinking behaviour and assess effectiveness of drinking interventions for older people.

Dysphagia-related acute stroke complications: A retrospective observational cohort study

OBJECTIVES

Post-stroke dysphagia is associated with aspiration pneumonia, but strategies intended to mitigate this complication, such as oral intake modifications, may unintentionally lead to dehydration-related complications such as urinary tract infections (UTIs) and constipation. This study aimed to determine the rates of aspiration pneumonia, dehydration, UTI and constipation in a large cohort of acute stroke patients and the independent predictors of each complication.

MATERIALS AND METHODS

Data were extracted retrospectively for 31,953 acute stroke patients admitted to six hospitals in Adelaide, South Australia over a 20-year period. Tests of difference compared rates of complications between patients with and without dysphagia. Multiple logistic regression modelling explored variables that significantly predicted each complication.

RESULTS

In this consecutive cohort of acute stroke patients, with a mean (SD) age of 73.8 (13.8) years and 70.2% presenting with ischaemic stroke, rates of complications were: aspiration pneumonia (6.5%); dehydration (6.7%); UTI (10.1%); and constipation (4.4%). Each complication was significantly more prevalent for patients with dysphagia compared to those without. Controlling for demographic and other clinical variables, the presence of dysphagia independently predicted aspiration pneumonia (OR=2.61, 95% CI 2.21-3.07; p<.001), dehydration (OR=2.05, 95% CI 1.76-2.38; p<.001), UTI (OR=1.34, 95% CI 1.16-1.56; p<.001), and constipation (OR=1.30, 95% CI 1.07-1.59; p=.009). Additional predictive factors were increased age and prolonged hospitalisation.

CONCLUSIONS

Aspiration pneumonia, dehydration, UTI, and constipation are common acute sequelae of stroke and independently associated with dysphagia. Future dysphagia intervention initiatives may utilise these reported complication rates to evaluate their impact on all four adverse health complications.

The characteristics of geriatric patients managed within the resuscitation unit of a district-level emergency centre in Cape Town

Introduction

The world's population is aging and this trend is also seen in South Africa. This increase will invariably affect acute care services. The geriatric population attending emergency centres have not been described in the South African setting. The objective was to describe the characteristics of geriatric patients presenting to the resuscitation unit of a district-level hospital in Cape Town.

Methods

All patients (≥65 years) managed within the resuscitation unit of Khayelitsha Hospital over an 8-month period (01 January–30 August 2018) were retrospective analysed. Data were collected from the Khayelitsha Hospital Emergency Centre database and by means of a retrospective chart review. Summary statistics are presented of all variables.

Results

A total of 225 patients were analysed. The median age was 71.1 years, 148 (65.8%) were female and all were residing in their family home. The majority (n = 162, 72%) presented outside office hours, 124 (55.1%) arrived by ambulance, and 94 (41.8%) had presented to the emergency centre within the previous year. Only half the patients (n = 114, 50.7%) were triaged as very urgent or higher. Most patients (n = 169, 75.1%) were admitted by in-hospital services and the in-hospital mortality was 21.8% (n = 49). Diseases related to the circulatory system (n = 54, 24.0%) were the most frequent primary diagnosis and acute kidney injury were the most frequent secondary diagnosis (n = 101, 44.9%). The most common comorbidities were hypertension (n = 176, 78.2%) and diabetes (n = 110, 48.9%), and 99 (44%) had three or more comorbidities. Polypharmacy (≥5 medications) occurred in 100 (44.4%) patients with 114 (50.7%) using medications from three or more different classes. The prevalence of hypernatremia was 2.6% and for hyponatremia 54.4%.

Conclusion

Geriatric patients managed within the resuscitation unit of a district-level hospital had a high return rate, multiple comorbidities and a high prevalence of polypharmacy and hyponatraemia.

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The average life expectancy in Africa is increasing

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Geriatric patients often present with multiple co-morbidities and polypharmacy

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Geriatric-friendly processes should be considered to ensure that geriatric patients are appropriately triaged and managed in the acute care setting

Microwave Hydration Monitoring: System Assessment Using Fasting Volunteers

Hydration is an important aspect of human health, as water is a critical nutrient used in many physiological processes. However, there is currently no clinical gold standard for non-invasively assessing hydration status. Recent work has suggested that permittivity in the microwave frequency range provides a physiologically meaningful metric for hydration monitoring. Using a simple time of flight technique for estimating permittivity, this study investigates microwave-based hydration assessment using a population of volunteers fasting during Ramadan. Volunteers are measured throughout the day while fasting during Ramadan and while not fasting after Ramadan. Comparing the estimated changes in permittivity to changes in weight and the time s fails to establish a clear relationship between permittivity and hydration. Assessing the subtle changes in hydration found in a population of sedentary, healthy adults proves difficult and more work is required to determine approaches suitable for tracking subtle changes in hydration over time with microwave-based hydration assessment techniques.

Impaired hydration status in acutely admitted older patients: prevalence and impact on mortality

BACKGROUND

impaired hydration is common in the older people, however studies of its effects on outcome in the acute setting are limited.

OBJECTIVES

to assess (i) the prevalence of impaired hydration, (ii) its relationship with laboratory markers of altered hydration and with (iii) short- and long-term mortality.

DESIGN

retrospective cohort study.

SETTING

University Hospital-Internal Medicine Department.

SUBJECTS

a total of 5,113 older patients consecutively acutely admitted from October 2015 to July 2016.

METHODS

according to calculated serum osmolarity at admission hydration status was stratified in: low osmolarity (<275 mmol/L), euhydration (275-295 mmol/L), impending (296-300 mmol/L) and current dehydration (>300 mmol/L). Relationships with serum sodium, potassium, glucose, urea, estimated glomerular filtration rate (eGFR), haematocrit, urea/creatinine ratio (Urea/Cr) and urine specific gravity (USG) were determined. Charlson Comorbidity Index, Modified Early Warning Score, Glasgow Prognostic Score, Norton score and Nutritional Risk Screening-2002 were calculated.

RESULTS

current and impending dehydration, euhydration and low-osmolarity were detected in 51.7, 17.1, 28.5 and 2.7% of the patients, respectively. Osmolarity correlated with urea (r = 0.846). Associations with serum sodium, creatinine, eGFR and urea/Cr were low but significant, being negligible that with USG and haematocrit. Serum sodium and urea increased in the transition from low- to high-osmolarity (P < 0.001 in all pairwise comparisons). In multivariate modelling current dehydration, functional dependence, clinical instability and high nutritional risk were associated (P < 0.001) with reduced short- and long-term survival.

CONCLUSIONS

impaired hydration is common in older people acutely admitted to medical care and is associated with poor outcome. Early assessment of calculated serum osmolarity is mandatory to target dehydration and hypoosmolar disorders.

Prevalence and risk factors of hypertonic dehydration among older patients admitted to the emergency department: A prospective cross-sectional study

AIM

The prevalence of hypertonic dehydration (HD) among community-dwelling and hospitalized populations has been evaluated. However, to our knowledge, no study had previously focused on older patients admitted to the emergency department (ED). The present study aimed to evaluate the prevalence, risk factors and short-term outcomes of HD among Thai older patients admitted to the ED.

METHODS

This was a prospective cross-sectional study at one urban ED in Thailand. Patients aged ≥65 years who were admitted to the ED were enrolled into the study. Data including clinical hydration status, Charlson Comorbidity Index (CCI) score, activities of daily living score, current use of medications, laboratory examination results and serum osmolarity level were collected. HD was defined as a serum osmolarity level of >300 mOsm/kg. The short-term outcomes were a 30-day ED revisit, hospital readmission and mortality rates.

RESULTS

In total, 80 (21.6%) of 370 patients presented with HD. A CCI score of ≥5 was found associated with HD among older patients (adjusted odds ratio: 1.82; 95% confidence interval: 1.03-3.21). The ED revisit rates were 18.1% in the dehydrated group and 10.9% in the non-dehydrated group. The hospital readmission rates were 8.3% in the dehydrated group and 10.6% in the non-dehydrated group. Furthermore, the 30-day mortality rates were 6.9% and 5.3% in the dehydrated and non-dehydrated groups, respectively.

CONCLUSIONS

One-fifth of older patients admitted to the ED presented with HD. A CCI score of ≥5 was considered a risk factor of HD. Moreover, further studies should focus on the long-term outcomes of HD and risk reduction. Geriatr Gerontol Int 2021; 21: 485-491.

Fasting and surgery timing (FaST) audit

BACKGROUND & AIMS

International guidance advocates the avoidance of prolonged preoperative fasting due to its negative impact on perioperative hydration. This study aimed to assess the adherence to these guidelines for fasting in patients undergoing elective and emergency surgery in the East Midlands region of the UK.

METHODS

This prospective audit was performed over a two-month period at five National Health Service (NHS) Trusts across the East Midlands region of the UK. Demographic data, admission and operative details, and length of preoperative fasting were collected on adult patients listed for emergency and elective surgery.

RESULTS

Of the 343 surgical patients included within the study, 50% (n = 172) were male, 78% (n = 266) had elective surgery and 22% (n = 77) underwent emergency surgery. Overall median fasting times (Q1, Q3) were 16.1 (13.0, 19.4) hours for food and 5.8 (3.5, 10.7) hours for clear fluids. Prolonged fasting >12 h was documented in 73% (n = 250) for food, and 21% (n = 71) for clear fluids. Median fasting times from clear fluids and food were longer in the those undergoing emergency surgery when compared with those undergoing elective surgery: 13.0 (6.4, 22.6) vs. 4.9 (3.3, 7.8) hours, and 22.0 (14.0, 37.4) vs. 15.6 (12.9, 17.8) hours respectively, p < 0.0001.

CONCLUSIONS

Despite international consensus on the duration of preoperative fasting, patients continue to fast from clear fluids and food for prolonged lengths of time. Patients admitted for emergency surgery were more likely to fast for longer than those having elective surgery.

Hyperosmolar dehydration: A predictor of kidney injury and outcome in hospitalised older adults

BACKGROUND & AIMS

Hospitalised older adults are vulnerable to dehydration. However, the prevalence of hyperosmolar dehydration (HD) and its impact on outcome is unknown. Serum osmolality is not measured routinely but osmolarity, a validated alternative, can be calculated using routinely measured serum biochemistry. This study aimed to use calculated osmolarity to measure the prevalence of HD (serum osmolarity >300 mOsm/l) and assess its impact on acute kidney injury (AKI) and outcome in hospitalised older adults.

METHODS

This retrospective cohort study used data from a UK teaching hospital retrieved from the electronic database relating to all medical emergency admissions of patients aged ≥ 65 years admitted between 1st May 2011 and 31st October 2013. Using these data, Charlson comorbidity index (CCI), National Early Warning Score (NEWS), length of hospital stay (LOS) and mortality were determined. Osmolarity was calculated using the equation of Krahn and Khajuria.

RESULTS

A total of 6632 patients were identified; 27% had HD, 39% of whom had AKI. HD was associated with a median (Q1, Q3) LOS of 5 (1, 12) days compared with 3 (1, 9) days in the euhydrated group, P < 0.001. Adjusted Cox-regression analysis demonstrated that patients with HD were four-times more likely to develop AKI 12-24 h after admission [Hazards Ratio (95% Confidence Interval) 4.5 (3.5-5.6), P < 0.001], and had 60% greater 30-day mortality [1.6 (1.4-1.9), P < 0.001], compared with those who were euhydrated.

CONCLUSION

HD is common in hospitalised older adults and is associated with increased LOS, risk of AKI and mortality. Further work is required to assess the validity of osmolality or osmolarity as an early predictor of AKI and the impact of HD on outcome prospectively.

Engineering Approaches to Assessing Hydration Status

Dehydration is a common condition characterized by a decrease in total body water. Acute dehydration can cause physical and cognitive impairment, heat stroke and exhaustion, and, if severe and uncorrected, even death. The health effects of chronic mild dehydration are less well studied with urolithiasis (kidney stones) the only condition consistently associated with it. Aside from infants and those with particular medical conditions, athletes, military personnel, manual workers, and older adults are at particular risk of dehydration due to their physical activity, environmental exposure, and/or challenges in maintaining fluid homeostasis. This review describes the different approaches that have been explored for hydration assessment in adults. These include clinical indicators perceived by the patient or detected by a practitioner and routine laboratory analyses of blood and urine. These techniques have variable accuracy and practicality outside of controlled environments, creating a need for simple, portable, and rapid hydration monitoring devices. We review the wide array of devices proposed for hydration assessment based on optical, electromagnetic, chemical, and acoustical properties of tissue and bodily fluids. However, none of these approaches has yet emerged as a reliable indicator in diverse populations across various settings, motivating efforts to develop new methods of hydration assessment.