Noninvasive Monitoring to Detect Dehydration: Are We There Yet?

The need for hydration monitoring is significant, especially for the very young and elderly populations who are more vulnerable to becoming dehydrated and suffering from the effects that dehydration brings. This need has been among the drivers of considerable effort in the academic and commercial sectors to provide a means for monitoring hydration status, with a special interest in doing so outside the hospital or clinical setting. This review of emerging technologies provides an overview of many technology approaches that, on a theoretical basis, have sensitivity to water and are feasible as a routine measurement. We review the evidence of technical validation and of their use in humans. Finally, we highlight the essential need for these technologies to be rigorously evaluated for their diagnostic potential, as a necessary step to meet the need for hydration monitoring outside of the clinical environment.

Postoperative Oral Rehydration and Regimented Follow-up Decrease Readmissions After Colorectal Surgery That Includes Ileostomies.

BACKGROUND: Ileostomies constitute 15% to 43% of readmissions after colorectal surgery, often due to dehydration and acute kidney injury. Prior institutional interventions decreased readmissions but not among patients who underwent new ileostomies. OBJECTIVE: To evaluate readmissions among patients who underwent new ileostomies after postoperative oral rehydration solution and standardized clinic visits. DESIGN: Retrospective analysis of prospective database. SETTINGS: Enhanced recovery colorectal surgery service. PATIENTS: Patients who underwent new ileostomy before and after intervention. INTERVENTIONS: Postoperative oral rehydration solution and postdischarge clinic visits with review of inputs/outputs, antimotility and appliance needs, and trained nurse reeducation 4 to 7 days after discharge, 30 days postoperatively, and every 1 to 2 weeks thereafter as needed. MAIN OUTCOME MEASURES: Readmission rate due to dehydration/acute kidney injury (primary), emergency department visits, and readmission rates overall and for specific diagnoses. Analysis used univariate and weighted techniques. RESULTS: A total of 312 patients (199 preintervention; 113 postintervention) were included, with a mean age of 59.0 years. Patients were predominantly White (94.9%) and evenly split between men and women. The most common diagnosis was diverticulitis (43.3%). The most common procedure was high anterior resection (38.8%), followed by low anterior resection (16.35%). Patient and procedure characteristics were well matched between groups. Multivariate analysis demonstrated that readmission rate due to dehydration/acute kidney injury significantly decreased between pre- and postintervention study groups (45.7% vs 16.5%, p = 0.039). Emergency department visits due to dehydration/acute kidney injury (12.0% vs 1.7%, p < 0.001) and readmissions from all causes (24.33% vs 10.6%, p = 0.005) also significantly decreased. Other complications were not significantly different between groups. Average stoma output 24 hours before (776 vs 625 mL, p = 0.005) and after (993 vs 890 mL, p = 0.025) discharge was significantly decreased in the postintervention group. LIMITATIONS: Retrospective single-center study. CONCLUSIONS: An oral rehydration solution and frequent standardized postdischarge visits led by trained nursing staff decreased readmissions and emergency department visits among patients who underwent new ileostomies after colorectal surgery. See Video Abstract . LA REHIDRATACIN ORAL POSOPERATORIA Y EL SEGUIMIENTO REGLAMENTADO REDUCEN LOS REINGRESOS EN PACIENTES DE CIRUGA COLORRECTAL CON ILEOSTOMAS: ANTECEDENTES:Las ileostomías constituyen del 15 al 43% de los reingresos después de la cirugía colorrectal, a menudo debido a la deshidratación y la lesión renal aguda. Las intervenciones institucionales previas redujeron los reingresos, pero no entre los pacientes con nuevas ileostomías.OBJETIVO:Evaluar los reingresos entre pacientes con nuevas ileostomías después del uso de solución de rehidratación oral postoperatoria y visitas clínicas estandarizadas.DISEÑO:Análisis retrospectivo de base de datos prospectiva.AJUSTES:Servicio de cirugía colorrectal de recuperación mejorada.PACIENTES:Pacientes con ileostomía nueva antes y después de la intervención.INTERVENCIÓN(ES):Solución de rehidratación oral posoperatoria y visitas clínicas posteriores al alta con revisión de entradas/salidas, antimotilidad y necesidades de aparatos, y reeducación de enfermeras capacitadas 4-7 días después del alta, 30 días después de la operación y cada 1-2 semanas después, según sea necesario.PRINCIPALES MEDIDAS DE RESULTADO:Tasa de readmisión debido a deshidratación/lesión renal aguda (primaria), tasa de urgencias y de readmisión en general y para diagnósticos específicos. El análisis utilizó técnicas univariadas y ponderadas.RESULTADOS:Se incluyeron un total de 312 pacientes (199 preintervención; 113 postintervención), con una edad media de 59,0 años. Los pacientes eran predominantemente blancos (94,9%) y se dividieron equitativamente entre hombres y mujeres. El diagnóstico más frecuente fue diverticulitis (43,3%). El procedimiento más común fue la resección anterior alta (38,8 %) seguida de la resección anterior baja (16,35 %). Las características del paciente y del procedimiento coincidieron bien entre los grupos. El análisis multivariante demostró que la tasa de reingreso debido a deshidratación/lesión renal aguda disminuyó significativamente entre los grupos de estudio antes y después de la intervención (45,7 % frente a 16,5 %, p = 0,039). Las visitas a urgencias por deshidratación/insuficiencia renal aguda (12,0 % frente a 1,7 %, p < 0,001) y los reingresos por todas las causas (24,33 % frente a 10,6 %, p = 0,005) también disminuyeron significativamente. Otras complicaciones no fueron significativamente diferentes entre los grupos. El gasto medio del estoma 24 horas antes (776 ml frente a 625 ml, p = 0,005) y después (993 ml frente a 890 ml, p = 0,025) del alta disminuyó significativamente en el grupo posterior a la intervención.LIMITACIONES:Estudio retrospectivo de centro único.CONCLUSIONES:Una solución de rehidratación oral y frecuentes visitas estandarizadas posteriores al alta dirigidas por personal de enfermería capacitado redujeron los reingresos y las visitas al servicio de urgencias entre los pacientes con nuevas ileostomías después de la cirugía colorrectal. ( Traducción-Dr. Yolanda Colorado ).

The weight, urine colour and thirst Venn diagram is an accurate tool compared with urinary and blood markers for hydration assessment at morning and afternoon timepoints in euhydrated and free-living individuals.

The weight, urine colour and thirst (WUT) Venn diagram is a practical hydration assessment tool; however, it has only been investigated during first-morning. This study investigated accuracy of the WUT Venn diagram at morning and afternoon timepoints compared with blood and urine markers. Twelve men (21 ± 2 years; 81·0 ± 15·9 kg) and twelve women (22 ± 3 years; 68·8 ± 15·2 kg) completed the study. Body mass, urine colour, urine specific gravity (USG), urine osmolality (UOSM), thirst and plasma osmolality (POSM) were collected at first-morning and afternoon for 3 consecutive days in free-living (FL) and euhydrated states. Number of markers indicating dehydration levels were categorised into either 3, 2, 1 or 0 WUT markers. Receiver operating characteristics analysis calculated the sensitivity and specificity of 1, 2 or 3 hydration markers in detecting dehydration or euhydration. Specificity values across morning and afternoon exhibited high diagnostic accuracy for USG (0·890-1·000), UOSM (0·869-1·000) and POSM (0·787-0·990) when 2 and 3 WUT markers were met. Sensitivity values across both timepoints exhibited high diagnostic accuracy for USG (0·826-0·941) and UOSM (0·826-0·941), but not POSM in the afternoon (0·324) when 0 and 1 WUT markers were met. The WUT Venn diagram is accurate in detecting dehydration for WUT2 and WUT3 based off USG, UOSM and POSM during first-morning and afternoon. Applied medical, sport and occupational practitioners can use this tool in field settings for hydration assessment not only at various timepoints throughout the day but also in FL individuals.

Validity of combined hydration self-assessment measurements to estimate a low vs. high urine concentration in a small sample of (tactical) athletes.

PURPOSE: Relationships between body weight, urine color (Uc), and thirst level (WUT) have been proposed as a simple and inexpensive self-assessment method to predict dehydration. This study aimed to determine if this method also allowed us to accurately identify a low vs. high urine concentration in (tactical) athletes. METHODS: A total of n = 19 Army Reserve Officer Training Corps cadets and club sports athletes (22.7 ± 3.8 years old, of which 13 male) were included in the analysis, providing morning body weight, thirst sensation, and Uc for five consecutive days. Each item received a score 0 or 1, resulting in a WUT score ranging from 0 (likely hydrated) to 3 (very likely dehydrated). WUT model and individual item outcomes were then compared with a ≥ 1.020 urine specific gravity (USG) cut-off indicating a high urine concentration, using descriptive comparisons, generalized linear mixed models, and logistic regression (to calculate the area under the curve (AUC)). RESULTS: WUT score was not significantly predictive of urine concentration, z = 1.59, p = 0.11. The AUC ranged from 0.54 to 0.77 for test days, suggesting a fair AUC on most days. Only Uc was significantly related to urine concentration, z = 2.49, p = 0.01. The accuracy of the WUT model for correctly classifying urine samples with a high concentration was 68% vs. 51% of samples with a low concentration, resulting in an average accuracy of 61%. CONCLUSION: This study shows that WUT scores were not predictive of urine concentration, and the method did not substantially outperform the accuracy of Uc scoring alone.

Fluid management in children with volume depletion.

Volume depletion is a common condition and a frequent cause of hospitalization in children. Proper assessment of the patient includes a detailed history and a thorough physical examination. Biochemical tests may be useful in selected cases. Understanding the pathophysiology of fluid balance is necessary for appropriate management. A clinical dehydration scale assessing more physical findings may help to determine dehydration severity. Most dehydrated children can be treated orally; however, intravenous therapy may be indicated in patients with severe volume depletion, in those who have failed oral therapy, or in children with altered consciousness or significant metabolic abnormalities. Proper management consists of restoring circulatory volume and electrolyte balance. In this paper, we review clinical aspects, diagnosis, and management of children with volume depletion.

Use of POCUS for the assessment of dehydration in pediatric patients-a narrative review.

In pediatric practice, POCUS (point-of-care ultrasound) has been mostly implemented to recognize lung conditions and pleural and pericardial effusions, but less to evaluate fluid depletion. The main aim of this review is to analyze the current literature on the assessment of dehydration in pediatric patients by using POCUS. The size of the inferior vena cava (IVC) and its change in diameter in response to respiration have been investigated as a tool to screen for hypovolemia. A dilated IVC with decreased collapsibility (< 50%) is a sign of increased right atrial pressure. On the contrary, a collapsed IVC may be indicative of hypovolemia. The IVC collapsibility index (cIVC) reflects the decrease in the diameter upon inspiration. Altogether the IVC diameter and collapsibility index can be easily determined, but their role in children has not been fully demonstrated, and an estimation of volume status solely by assessing the IVC should thus be interpreted with caution. The inferior vena cava/abdominal aorta (IVC/AO) ratio may be a suitable parameter to assess the volume status in pediatric patients even though there is a need to define age-based thresholds. A combination of vascular, lung, and cardiac POCUS could be a valuable supplementary tool in the assessment of dehydration in several clinical scenarios, enabling rapid identification of life-threatening primary etiologies and helping physicians avoid inappropriate therapeutic interventions.   Conclusion: POCUS can provide important information in the assessment of intravascular fluid status in emergency scenarios, but measurements may be confounded by a number of other clinical variables. The inclusion of lung and cardiac views may assist in better understanding the patient's physiology and etiology regarding volume status. What is Known: • In pediatric practice, POCUS (point-of-care ultrasound) has been mostly implemented to recognize lung conditions (like pneumonia and bronchiolitis) and pleural and pericardial effusions, but less to evaluate fluid depletion. • The size of the IVC (inferior vena cava) and its change in diameter in response to respiration have been studied as a possible screening tool to assess the volume status, predict fluid responsiveness, and assess potential intolerance to fluid loading. What is New: • The IVC diameter and collapsibility index can be easily assessed, but their role in predicting dehydration in pediatric age has not been fully demonstrated, and an estimation of volume status only by assessing the IVC should be interpreted carefully. • The IVC /AO(inferior vena cava/abdominal aorta) ratio may be a suitable parameter to assess the volume status in pediatric patients even though there is a need to define age-based thresholds. A combination of vascular, lung, and cardiac POCUS can be a valuable supplementary tool in the assessment of intravascular volume in several clinical scenarios.

Blood, Sweat, and Tears: Implications for Hydration Testing in Combat Sports-Investigating Body Mass Loss and Biomarker Changes.

Combat sports athletes often undergo rapid body mass loss (BML), which presents health risks. Hydration testing has been proposed as a possible solution to reduce or eliminate rapid BML. However, combat sports athletes may exhibit distinct physiological characteristics due to repeated exposure to BML. Thus, traditional and emerging hydration biomarkers should be investigated to determine their potential suitability for field use in this cohort. This study examined whether BML can explain changes in serum and urine osmolality (SosmΔ, UosmΔ), tear osmolarity (TosmΔ), hematocrit (HctΔ), and urine-specific gravity (USGΔ) after mild-moderate passive dehydration. Biomarker reliability was also assessed across two trials. Fifteen male and female combat sports athletes (age: 26.3 ± 5.3 years, body mass: 67.7 ± 9.9 kg) underwent a sauna protocol twice (5-28 days apart) aiming for 4% BML. The average BML in Trials 1 and 2 was 3.0 ± 0.7%. Regression analysis revealed that BML explained HctΔ (R2 = 0.22, p = 0.009) but not SosmΔ (R2 = 0.11, p = 0.079) or other biomarkers. Intraclass correlation coefficients (ICCs) were significant for all biomarkers except TosmΔ (ICC = 0.06, p = 0.37) and post-Tosm (ICC = 0.04, p = 0.42); post-Hct performed best (ICC = 0.82, p < 0.001). Contingency tables with post-Sosm (295 mOsm/kg) and post-USG (1.020) cutoffs revealed an 80% true negative rate (TNR) and a 62% true positive rate (TPR). Increasing the Sosm cutoff to 301 mOsm/kg decreased the TNR to 52% but increased the TPR to 83%. Although blood parameters were most sensitive to BML, they could only explain 11%-22% of biomarker variation. The typical USG cutoff misclassified 42% of athletes postdehydration, and reliability was generally poor-moderate. Alternative strategies should be pursued to manage rapid BML in combat sports.

Challenges in using fractional excretion of sodium in the assessment of salt poisoning.

AIM: Hypernatraemia typically reflects dehydration, yet in rare instances may be caused by salt poisoning. Identifying these rare cases is a difficult challenge. Making the diagnosis of salt poisoning can have severe consequences, such as the removal of the child from its home or even prison sentences for the implicated carer. It is therefore imperative to get the diagnosis right. Guidelines for the assessment of hypernatraemia emphasise the importance of the fractional excretion of sodium to distinguish between dehydration and salt poisoning, but no generally accepted cut-off value exists. Opinions about the diagnosis of salt poisoning in some cases consequently may differ. Here, we aim to highlight the challenges and stimulate discussion on how to improve the tools for the assessment of hypernatraemia. METHODS: Report of a case of unexplained hypernatraemia in which the treating paediatrician raised the suspicion of salt poisoning. RESULTS: Two consulted experts made opposing judgements about the aetiology of the observed hypernatraemia. CONCLUSION: Clear diagnostic criteria for the diagnosis of salt poisoning are lacking and more data are needed for their establishment. Without this, victims may experience further harm and carers are at risk of devastating, yet potentially erroneous accusations.

Non-invasive technology to assess hydration status in advanced cancer to explore relationships between fluid status and symptoms: an observational study using bioelectrical impedance analysis.

BACKGROUND: Oral fluid intake decreases in advanced cancer in the dying phase of illness. There is inadequate evidence to support the assessment, and management, of hydration in the dying. Bioelectrical impedance analysis (BIA) is a body composition assessment tool. BIA has the potential to inform clinal management in advanced cancer, by examining the relationships between hydration status and clinical variables. AIM: BIA was used to determine the association between hydration status, symptoms, clinical signs, quality-of-life and survival in advanced cancer, including those who are dying (i.e. in the last week of life). MATERIALS AND METHODS: We conducted a prospective observational study of people with advanced cancer in three centres. Advance consent methodology was used to conduct hydration assessments in the dying. Total body water was estimated using the BIA Impedance index (Height - H (m)2 /Resistance - R (Ohms)). Backward regression was used to identify factors (physical signs, symptoms, quality of life) that predicted H2/R. Participants in the last 7 days of life were further assessed with BIA to assess hydration changes, and its relationship with clinical outcomes. RESULTS: One hundred and twenty-five people participated (males n = 74 (59.2%), females, n = 51 (40.8%)). We used backward regression analysis to describe a statistical model to predict hydration status in advanced cancer. The model demonstrated that 'less hydration' (lower H2/R) was associated with female sex (Beta = -0.39, p < 0.001), increased appetite (Beta = -0.12, p = 0.09), increased dehydration assessment scale score (dry mouth, dry axilla, sunken eyes - Beta = -0.19, p = 0.006), and increased breathlessness (Beta = -0.15, p = 0.03). 'More hydration' (higher H2/R) was associated with oedema (Beta = 0.49, p < 0.001). In dying participants (n = 18, 14.4%), hydration status (H2/R) was not significantly different compared to their baseline measurements (n = 18, M = 49.6, SD = 16.0 vs. M = 51.0, SD = 12.1; t(17) = 0.64, p = 0.53) and was not significantly associated with agitation (rs = -0.85, p = 0.74), pain (rs = 0.31, p = 0.23) or respiratory tract secretions (rs = -0.34, p = 0.19). CONCLUSIONS: This is the first study to use bioimpedance to report a model (using clinical factors) to predict hydration status in advanced cancer. Our data demonstrates the feasibility of using an advance consent method to conduct research in dying people. This method can potentially improve the evidence base (and hence, quality of care) for the dying. Future BIA research can involve hydration assessment of cancers (according to type and stage) and associated variables (e.g., stage of illness, ethnicity and gender). Further work can use BIA to identify clinically relevant outcomes for hydration studies and establish a core outcome set to evaluate how hydration affects symptoms and quality-of-life in cancer.

Clinical Profile and Outcome of Young Infants With Hypernatremic Dehydration Presenting to the Emergency Department.

OBJECTIVES: The aim of this study was to evaluate the clinical profile and outcome of young infants presenting to the pediatric emergency department with hypernatremic dehydration. METHODS: A prospective observational study was conducted at a tertiary care teaching hospital over a period of 18 months. All outborn sick young infants aged 2 months or younger who presented to the emergency department with symptoms and signs of possible sepsis and/or dehydration were screened, and those with hypernatremia were enrolled in the study. Those infants born at less than 37 weeks of gestation and gross congenital anomaly were excluded. Hypernatremic dehydration was defined as serum sodium levels (Se Na+)higher than 145 mEq/L. Variables used in the study were defined as per standard definitions. Acute kidney injury was defined and staged using serum creatinine as per modified neonatal Kidney Disease Improving Global Outcome guidelines. Clinical presentation, laboratory parameters, and comorbidities were compared among outcome groups (survived and died). RESULTS: Of 1124 outborn young infants who met the eligibility criteria for screening, 63 were diagnosed to have hypernatremic dehydration and 55 were enrolled. The hospital-based period prevalence of hypernatremic dehydration in young infants was 4.89%. The median age of presentation was 17 days (10-30). Male-to-female ratio was 1.1:1. Seventy-three percent were first in birth order. Feeding pattern showed 61.8%, 30.9%, and 7.3% of infants were exclusively breastfed, top fed, and mixed fed, respectively. The median serum sodium at the time of admission was 160 (153.5-167) mg/dL. Three (5.5%) infants had mild, 39 (70.9%) had moderate, and 13 (23.6%) had severe hypernatremic dehydration. There was statistically significant correlation between median platelet count with severity of hypernatremic dehydration. The mean time taken to correct serum sodium level was 3.30 ± 1.60 days. The case fatality rate was 41.8%. Those who died had statistically more severe hypernatremic dehydration, acute kidney injury, sepsis, and need for ventilation. CONCLUSIONS: Acute kidney injury stage 3, shock, and need for ventilation are associated with poor outcome in infants with hypernatremic dehydration.

A New Method for Detecting Dehydration of the Human Body Using Non-Contact Millimeter Wave Radiometry.

Dehydration is a common problem in the aging population. Medical professionals can detect dehydration using either blood or urine tests. This requires experimental tests in the lab as well as urine and blood samples to be obtained from the patients. This paper proposed 100 GHz millimeter wave radiometry for early detection of dehydration. Reflectance measurements were performed on healthy and dehydrated patients of both genders (120 males and 80 females) in the aging population. Based on the cause of dehydration, the patient groups were divided into three categories: (1) patients dehydrated due to less thirst sensation, (2) patients dehydrated due to illnesses (vomiting and diarrhea), and (3) patients dehydrated due to diabetes. Reflectance measurements were performed on eight locations: (1) the palm, (2) the back of the hand, (3) the fingers, (4) the inner wrist, (5) the outer wrist, (6) the volar side of the arm, (7) the dorsal surface of the arm, and (8) the elbow. Skin dehydrated due to vomiting and diarrhea was found to have lower reflectance at all the measurement locations compared with healthy and other types of dehydrated skin. The elbow region showed the highest difference in reflectance between healthy and dehydrated skin. This indicates that radiometric sensitivity is sufficient to detect dehydration in a few seconds. This will reduce the patient's waiting time and the healthcare professional's intervention time as well as allow early treatment of dehydration, thus avoiding admission to hospitals.

Applicability of thermography as a potential non-invasive technique to assess the body-thermal status of heat-stressed and water-deprived goats (Capra hircus).

To evaluate the use of infrared thermography to assess the thermal status of heat-stressed and water-deprived Capra hircus, full-body surface temperature (TS) and six other body-thermal variables [core, rectal (TR), and skin (TSK) temperatures, respiratory and heart rates, and total body-thermal gradient (core-to-ambient, BTG)] were measured after three days of euhydration (EU), dehydration (DE), and rehydration (RE). Results revealed that the combined effect of heat stress and water deprivation had affected all tested variables including the TS, and once these animals gained access to water in the RE stage variables returned to their EU levels. Moreover, there were positive correlations between TS and all variables with the exception of BTG. From these six variables, only three variables (i.e. the TR, TSK, and BTG) during the DE stage and two variables (i.e. the TSK and BTG) throughout the experimental stages showed higher constancy (R2 ≥ 0 75, P < 0 001; agreement intervals ±1 96 95 % CI) with TS. However, BTG appeared more closely correlated with TS, representing the body-thermal status more realistically than other variables. In effect, the mean and thresholds of the BTG were predicted using the recorded TS and were within 0.02 °C of original estimates. Collectively, these findings show that infrared thermography is appropriate for assessing body-thermal status, and thus the welfare, of these animals under the three conditions studied, and conclude that full-body TS can be a surrogate proxy for BTG in these animals. Further experiments are needed to adequately examine the reproducibility of these results under biometeorologically-simulated environments and natural habitats.

Assessment of Hydration Status Using Conventional Method and Salivary Osmolarity as a Point-of-care Tool.

Dehydration is a well-known problem worldwide, and its assessment can be challenging due to confusing physical signs. The most effective way to assess hydration status is through the costly stable isotope methodology, but this approach has practical limitations. More commonly accepted and utilized indicators of hydration status are hematological and urinary parameters. However, hematological markers require invasive methods, and urinary markers have varying degrees of success in tracking hydration changes. While alterations in body weight can serve as a means of promptly evaluating hydration status, various factors such as food consumption, fluid intake, fecal losses, and urine production can impact these changes. Researchers have turned their attention to saliva as a potential marker and point-of-care (POC) testing to address the limitations of existing biomarkers. Saliva is appealing due to its easy collection process and similarities to extracellular fluid in terms of water and ion concentrations. Recent studies have shown that saliva flow rate, osmolarity/osmolality, and total protein concentration can effectively monitor changes in body mass during acute dehydration. Misdiagnosing dehydration can have severe clinical consequences, leading to morbidity and even mortality. This narrative review focuses on recognizing the significance of hydration assessment, monitoring, and the potential of salivary osmolarity (SOSM) as an assessment tool. Healthcare professionals can improve their practices and interventions to optimize hydration and promote overall wellness using such tools.

Clinical and Laboratory Predictors of Dehydration Severity in Children With Diabetic Ketoacidosis.

STUDY OBJECTIVE: Our primary objective was to characterize the degree of dehydration in children with diabetic ketoacidosis (DKA) and identify physical examination and biochemical factors associated with dehydration severity. Secondary objectives included describing relationships between dehydration severity and other clinical outcomes. METHODS: In this cohort study, we analyzed data from 753 children with 811 episodes of DKA in the Pediatric Emergency Care Applied Research Network Fluid Therapies Under Investigation Study, a randomized clinical trial of fluid resuscitation protocols for children with DKA. We used multivariable regression analyses to identify physical examination and biochemical factors associated with dehydration severity, and we described associations between dehydration severity and DKA outcomes. RESULTS: Mean dehydration was 5.7% (SD 3.6%). Mild (0 to <5%), moderate (5 to <10%), and severe (≥10%) dehydration were observed in 47% (N=379), 42% (N=343), and 11% (N=89) of episodes, respectively. In multivariable analyses, more severe dehydration was associated with new onset of diabetes, higher blood urea nitrogen, lower pH, higher anion gap, and diastolic hypertension. However, there was substantial overlap in these variables between dehydration groups. The mean length of hospital stay was longer for patients with moderate and severe dehydration, both in new onset and established diabetes. CONCLUSION: Most children with DKA have mild-to-moderate dehydration. Although biochemical measures were more closely associated with the severity of dehydration than clinical assessments, neither were sufficiently predictive to inform rehydration practice.

Total water intake guidelines are sufficient for optimal hydration in United States adults.

PURPOSE: Recent studies suggest that 24-h urine osmolality (UOsm) for optimal water intake should be maintained < 500 mmol·kg-1. The purpose of this study was to determine the total water intake (TWI) requirement for healthy adults to maintain optimal hydration as indicated by 24-h urine osmolality < 500 mmol·kg-1. METHODS: Twenty-four-hour UOsm was assessed in 49 men and 50 women residing in the United States (age: 41 ± 14 y, body mass index: 26.3 ± 5.2 kg·m-2). TWI was assessed from 7-day water turnover, using a dilution of deuterium oxide, corrected for metabolic water production. The diagnostic accuracy of TWI to identify UOsm < 500 mmol·kg-1 was evaluated using receiver operating characteristic (ROC) analysis in men and women separately. RESULTS: Twenty-four-hour UOsm was 482 ± 229 and 346 ± 182 mmol·kg-1 and TWI was 3.57 ± 1.10 L·d-1 and 3.20 ± 1.27 L·d-1 in men and women, respectively. ROC analysis for TWI detecting 24-h UOsm < 500 mmol·kg-1 in men yielded an area under the curve (AUC) of 77.4% with sensitivity, specificity, and threshold values of 83.3%, 64.5%, and 3.39 L·d-1, respectively. The AUC was 82.4% in women with sensitivity, specificity, and threshold values of 85.7%, 72.1%, and 2.61 L·d-1. CONCLUSION: Considering threshold values in men and women of 3.4 L·d-1 and 2.6 L·d-1, respectively, maintaining TWI in line with National Academy of Medicine guidelines of 3.7 L·d-1 in men and 2.7 L·d-1 in women should be sufficient for most individuals in the United States to maintain 24-h UOsm < 500 mmol·kg-1.

Comparison between digital and paper urine color to assess hydration status.

PURPOSE: The purpose of this study was to investigate associations between digital urine color and paper urine color with other urine indices to assess hydration status. METHODS: Twelve male subjects (mean ± standard deviation; age, 26 ± 8 years; body mass, 57.8 ± 5.3 kg; height, 177.5 ± 8.9 cm; VO2max, 57.8 ± 5.8 ml·kg-1·min-1) performed four exercise trials in the heat. Before and following exercise trials, subjects provide urine samples. Urine samples were measured using a digital urine color chart on a portable device screen. Urine samples were also assessed with urine specific gravity (USG), urine osmolality (UOsmo), and a validated paper urine color chart. RESULTS: There were extremely large associations found between digital urine color and paper urine color (r = 0.926, p < 0.001). Correlation coefficients showing associations with USG and UOsmo were similar between digital urine color (USG, r = 0.695, p < 0.001; UOsmo, r = 0.555, p < 0.001) and paper urine color (USG, r = 0.713, p < 0.001; UOsmo, r = 0.570, p < 0.001). Bland-Altman analysis indicated that no proportional bias was observed between digital and paper urine colors (bias, - 0.148; SD of bias, 0.492; 95% LOA, - 1.11, 0.817; p = 0.094). CONCLUSIONS: Strong associations were found between digital and paper urine colors with no proportional bias. Furthermore, the degree of associations with USG and UOsmo was similar between digital and paper urine color. These results indicate that digital urine color is a useful tool to assess hydration status and this method could be used as an alternative method to using paper urine color.

New horizons in the diagnosis and management of dehydration.

Hydration is a fundamental aspect of clinical practice and yet it is an under-researched topic, particularly in older people, leading to many areas of uncertainty. There are two types of dehydration; hypertonic, which is a water deficit, and isotonic, which is a deficit of both water and salt. Individual clinical signs and bedside tests are poor diagnostic tools, making dehydration difficult to identify. However, the diagnostic value of a holistic clinical approach is not known. The gold-standard clinical test for dehydration is serum osmolality, but this cannot diagnose isotonic dehydration and may delay diagnosis in acute situations. Salivary osmolality point-of-care testing is a promising and rapid new diagnostic test capable of detecting both hypertonic and isotonic dehydration in older people, but further evidence to support its clinical utility is needed. Daily fluid requirements may be less than previously thought in adults, but the evidence specific to older people remains limited. Hydration via the subcutaneous route is safer and easier to initiate than the intravenous route but is limited by infusion speed and volume. Prompting older adults more frequently to drink, offering a wider selection of drinks and using drinking vessels with particular features can result in small increases in oral intake in the short-term. The ongoing clinically-assisted hydration at end of life (CHELsea II) trial will hopefully provide more evidence for the emotive issue of hydration at the end of life.

A systematic review of tools for predicting complications in patients with acute infectious diarrhea.

OBJECTIVE: To identify tools that predict the risk of complications in patients presenting to outpatient clinics or emergency departments (ED) with acute infectious diarrhea. METHODS: Medline, Embase, Cochrane Library, Web of Science and CINAHL were searched from inception to July 2021. Articles reporting on the derivation or validation of a score to stratify the risk of intravenous rehydration or hospitalization among patients with acute infectious diarrhea in the ED or outpatient clinic were retained for analysis. RESULTS: Five articles reporting on two different tools were identified. Developed to assess the risk of hospitalization of children, the EsVida scale has not been externally validated. Developed originally to assess the level of dehydration in children, the Clinical Dehydration Scale (CDS) was evaluated as a risk stratification tool. For predicting intravenous rehydration, a CDS score ≥ 1 showed a sensitivity between 0.73 and 0.88 and specificity between 0.38 and 0.69, whereas a CDS score ≥ 5 showed a sensitivity between 0.06 and 0.32 and specificity between 0.94 and 0.99. For predicting hospitalization, a CDS score ≥ 1 showed a sensitivity between 0.74 and 1.00 and specificity between 0.34 and 0.38, whereas a CDS score ≥ 5 showed a sensitivity between 0.26 and 0.62 and specificity between 0.66 and 0.96. High heterogeneity among studies and unclear risk of bias precluded meta-analysis. CONCLUSION: As a risk-stratification tool, the CDS has been validated only for children. Further research is needed to develop and validate a tool suitable for adults in the ED.

The uric acid-urea distribution volume ratio is a potential marker of hydration status in patients on hemodialysis.

The distribution volume of uric acid is affected by the amount of extracellular water (ECW), while urea distribution volume can be considered as total body water (TBW). Thus, the ratio of distribution volumes of uric acid and urea can be paralleled to and be considered as the proxy of ECW/TBW. A total of 108 patients at our facility was included. The uric acid and urea distribution volume ratio (UUVdR) calculated from the single-pool model, which was measured within 1 month of the time when the bioimpedance index was measured. ECW/TBW at the end of the HD session was measured by InBody S10. We investigated the association between the UUVdR and the ECW/TBW values and the factors affecting the residuals of the regression equation. We also evaluated the predictive ability of overhydration or dehydration in randomly selected two groups, i.e., the training group and the validation group. ECW/TBW correlated highly with UUVdR. Multivariate analysis demonstrated that only creatinine and ECW/TBW were significantly associated with regression residuals. The cutoff values of UUVdR for overhydration and dehydration were 0.666 and 0.579, respectively, in the training group. Their AUC were 0.872 and 0.898, respectively. The sensitivity and specificity values in the validation group were 0.571 and 0.868 for overhydration, and 0.444 and 0.953 for dehydration, respectively. UUVdR might be a proxy of hydration status in hemodialysis patients. It may be possible to predict hydration status without dedicated devices in the epidemiological study.

A Deadly Case of Dehydration: Organic Acidemias in the Emergency Department.

BACKGROUND: Organic acidemias are rare genetic mutations, most commonly identified in the newborn period. Late-onset presentations present a diagnostic conundrum. Early identification and appropriate management can be lifesaving. CASE REPORT: We describe the case of a 3-year-old boy who presented to urgent care with 2 days of nausea, vomiting, and diarrhea followed by respiratory distress, shock, and encephalopathy. Brisk recognition of his shock state led to an urgent transfer to a tertiary care pediatric emergency department by air where his shock was treated and hyperammonemia was uncovered, leading to the diagnosis of late-onset propionic acidemia, which was subsequently managed with a good outcome. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Late-onset presentations of inborn errors of metabolism, including organic acidemias, represent one of the most challenging pediatric cases an emergency physician can encounter. This case reviews the management and diagnosis of a late-onset inborn error of metabolism and emphasizes how prompt diagnosis and treatment can lead to a favorable outcome.