Evaluation of a Clinical Dehydration Scale in Children Requiring Intravenous Rehydration Laura M. Kinlin and Stephen B. Freedman Pediatrics 2012;129;e1211; originally published online April 23, 2012; DOI: 10.1542/peds.2011-2985 The online version of this article, along with updated information and services, is located on the World Wide Web at: http://pediatrics.aappublications.org/content/129/5/e1211.full.html PEDIATRICS is the official journal of the American Academy of Pediatrics. A monthly publication, it has been published continuously since 1948. PEDIATRICS is owned, published, and trademarked by the American Academy of Pediatrics, 141 Northwest Point Boulevard, Elk Grove Village, Illinois, 60007. Copyright © 2012 by the American Academy of Pediatrics. All rights reserved. Print ISSN: 0031-4005. Online ISSN: 1098-4275. Downloaded from pediatrics.aappublications.org by guest on August 22, 2014 ARTICLE Evaluation of a Clinical Dehydration Scale in Children Requiring Intravenous Rehydration AUTHORS: Laura M. Kinlin, BSc, MPH,a and Stephen B. Freedman, MDCM, MSc, FRCPC, FAAPb aFaculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada; and bDivisions of Pediatric Emergency Medicine and Gastroenterology, Hepatology, and Nutrition, and Child Health Evaluative Sciences, The Hospital for Sick Children, Departments of Pediatrics, and Health Policy, Management and Evaluation, University of Toronto, Faculty of Medicine, Toronto, Ontario, Canada KEY WORDS dehydration, gastroenteritis, clinical score, severity of illness, emergencies ABBREVIATIONS AUC—area under the curve CDS—clinical dehydration scale CI—conﬁdence interval ED—emergency department IQR—interquartile range ROC—receiver operating characteristic Dr Freedman is the guarantor of this article and declares that he participated in the design of this study and revisions of the article; Dr Freedman also takes full responsibility for the work and conduct of the study, the integrity of the data, and the decision to publish. Ms Kinlin made substantial contribution to analysis and interpretation of data, drafting of the article for publication, and she has seen and approved the version to be published. This study is a secondary analysis of data collected as part of a clinical trial, which was registered at www.clinicaltrials.gov (identiﬁer NCT00392145). The main content of the clinical trial has been published by the British Medical Journal. Two other manuscripts arising from the original clinical trial data set are currently under review by other journals. The authors of all manuscripts attest to the fact that all manuscripts contain unique information and minimal if any overlapping content. www.pediatrics.org/cgi/doi/10.1542/peds.2011-2985 doi:10.1542/peds.2011-2985 Accepted for publication Jan 12, 2012 Address correspondence to Stephen B. Freedman, MDCM, MSc, FRCPC, FAAP, Division of Pediatric Emergency Medicine, The Hospital for Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8. E-mail: [email protected] (Continued on last page) WHAT’S KNOWN ON THIS SUBJECT: Evaluating dehydration severity is a challenging task. Clinical dehydration scores that combine multiple clinical ﬁndings are promising. One clinical dehydration scale score has been developed and subsequently evaluated; however, few participants in the derivation and validation studies were signiﬁcantly dehydrated. WHAT THIS STUDY ADDS: In children requiring intravenous rehydration, the dehydration scale displayed moderate reliability and weak associations with objective measures. Thus, although the scale can assist in assessing dehydration, it should not be used in isolation to dictate interventions (eg, intravenous rehydration, hospitalization). abstract OBJECTIVES: To evaluate the reliability and validity of a previously derived clinical dehydration scale (CDS) in a cohort of children with gastroenteritis and evidence of dehydration. METHODS: Participants were 226 children older than 3 months who presented to a tertiary care emergency department and required intravenous rehydration. Reliability was assessed at treatment initiation, by comparing the scores assigned independently by a trained research nurse and a physician. Validity was assessed by using parameters reﬂective of disease severity: weight gain, baseline laboratory results, willingness of the physician to discharge the patient, hospitalization, and length of stay. RESULTS: Interobserver reliability was moderate, with a weighted k of 0.52 (95% conﬁdence interval [CI] 0.41, 0.63). There was no correlation between CDS score and percent weight gain, a proxy measure of ﬂuid deﬁcit (Spearman correlation coefﬁcient = 20.03; 95% CI 20.18, 0.12). There were, however, modest and statistically signiﬁcant correlations between CDS score and several other parameters, including serum bicarbonate (Pearson correlation coefﬁcient = 20.35; 95% CI 20.46, 20.22) and length of stay (Pearson correlation coefﬁcient = 0.24; 95% CI 0.11, 0.36). The scale’s discriminative ability was assessed for the outcome of hospitalization, yielding an area under the receiver operating characteristic curve of 0.65 (95% CI 0.57, 0.73). CONCLUSIONS: In children administered intravenous rehydration, the CDS was characterized by moderate interobserver reliability and weak associations with objective measures of disease severity. These data do not support its use as a tool to dictate the need for intravenous rehydration or to predict clinical course. Pediatrics 2012;129:e1211–e1219 PEDIATRICS Volume 129, Number 5, May 2012 Downloaded from pediatrics.aappublications.org by guest on August 22, 2014 e1211 In the United States, gastroenteritis accounts for .1.5 million outpatient visits and 200 000 hospitalizations annually.1 Treatment guidelines use goal-directed therapy, with recommendations based on assessment of dehydration severity1–3; however, this can be a challenge as there is “a lack of compelling evidence to support efforts to accurately distinguish varying degrees of dehydration on the basis of symptoms and signs.”2 Percent decrease in body weight, recognized as an objective “gold standard,”2 often cannot be calculated because baseline hydrated weights are rarely available at acute-care visits.4 Consequently, traditional teaching has encouraged grouping children, based on several variables, into 3 categories: mild, moderate, and severe.5,6 Recent guidelines have acknowledged the limitations of this approach, and divide patients into minimal (,3%–5%), some (ie, mild-moderate, 5%–10%), and severe dehydration (.10%)1,3,7; however, physicians classify children with “some” dehydration correctly only 33% of the time.8 Inaccurate assessments have important ramiﬁcations: underestimation may result in delayed therapy; overestimation may lead to unnecessary interventions, complications and costs.9 Recently, a clinical dehydration scale (CDS) has been developed10 and undergone validation11,12; however, these reports have included few subjects with signiﬁcant dehydration. Moreover, interobserver reliability has not been evaluated, and the studies have been underpowered to evaluate the correlation between CDS score and biochemical parameters. Before widespread adoption of the CDS, further evaluation is necessary to establish that it produces consistent results and correlates with meaningful measures of disease severity.13 We sought to evaluate the reliability and validity of Friedman et al’s CDS10 in a cohort of children who presented to e1212 a pediatric emergency department (ED) with gastroenteritis and dehydration. Our primary objective was to evaluate interobserver reliability by using independent, simultaneous, blinded assessments. The secondary objective was to explore validity by examining the score’s association with other clinical data. METHODS Setting and Participants Between December 2006 and April 2010, data were prospectively collected on 226 children $3 months of age who presented to The Hospital for Sick Children’s ED (Toronto, Ontario) with gastroenteritis and dehydration requiring intravenous rehydration. The study was approved by the hospital’s research ethics board. Written informed consent was obtained from the guardians of all participants. Eligibility criteria were a diagnosis of acute gastroenteritis, evidence of dehydration, and a decision to administer intravenous rehydration therapy. The diagnosis of gastroenteritis was at the discretion of the supervising physician; “acute” implied ,6 days of symptoms. Dehydration was deﬁned based on the presence of one of the following features as assigned by a trained research nurse: (1) CDS $3 (Table 1)10,11; (2) capillary reﬁll time $2 seconds15; (3) abnormal skin turgor, with prolonged retraction time and “tenting”15; or (4) abnormal respiratory pattern (.50 breaths per minute for children aged ,12 months; .40 breaths per minute for children aged $12 months).15 All potentially eligible children underwent a trial of oral rehydration therapy conducted with administration of 5 mL of a ﬂavored oral rehydration solution through a syringe every 5 minutes, with the rate increased based on tolerance and the child’s weight.1 For children with persistent vomiting, ondansetron was administered orally. Subsequently, based on the success of oral rehydration, the decision regarding the need for intravenous rehydration was made by the responsible physician, unaware of the CDS score assigned by the nurse. Exclusion criteria were weight ,5 kg; presence of a signiﬁcant underlying disease that would affect hydration assessment (eg, renal insufﬁciency, diabetes mellitus); suspicion of previously undiagnosed cardiac or renal disease; history of abdominal surgery or presence of an acute surgical abdomen; history of signiﬁcant head, chest, or abdominal trauma within 7 days; evidence of hypotension, hypoglycemia (,2.8 mmol/L), or hyperglycemia (.11.0 mmol/L); and previous study enrollment. Procedures Children were assessed for eligibility once the treating physician had determined that intravenous rehydration was required. Eligible children then had CDS scores assigned by a research nurse and the responsible physician, who was blinded to the score recorded by the nurse and unaware that interobserver scores would be calculated. Thirty-one physicians, who received no formal training in using the CDS but were provided with standardized deﬁnitions (Table 1), assigned scores. All children had the following investigations performed at the time of intravenous insertion (Advia IMS Integrated Modular System [Bayer, Elkhart, IN], accuracy = 60.3 mmol/L): sodium, potassium, chloride, pH, bicarbonate, carbon dioxide, glucose, blood urea nitrogen, and creatinine. CDS scores were subsequently documented by the research nurse every 30 minutes for 4 hours. Patient Assessment and Data Collection Data elements collected included basic demographics, historical variables (eg, number of vomiting episodes in the preceding 24 hours), and clinical KINLIN and FREEDMAN Downloaded from pediatrics.aappublications.org by guest on August 22, 2014 ARTICLE TABLE 1 Friedman et al’s10 CDSa Characteristic Score of 0 Score of 1 Score of 2 General appearance Normalb Eyes Mucous membranesc Tears Normal Moist Tears Thirsty, restless, or lethargic but irritable when touched Slightly sunken Sticky Decreased tears Drowsy, limp, cold, sweaty; comatose or not Very sunken Dry Absent tears Scores for the individual items are summed. a Higher scores indicate more severe dehydration. Scores range from 0 to 8. A score of 0 correlates with ,3% dehydration (positive likelihood ratio 2.2; 95% CI 0.9–5.3), scores of 1–4 correlate with some (3%–6%) dehydration (positive likelihood ratio 1.3, 95% CI 0.9, 1.7), and 5–8 correlates with moderate to severe ($6%) dehydration (positive likelihood ratio 5.2; 95% CI 2.1, 12.8).14 b “Normal” includes children who may be sleeping but are easily aroused to a normal level of consciousness. This assessment takes into account the time of day and the child’s usual pattern as described by the child’s guardian. c This is assessed on the buccal mucosa and tongue, and not the lips. examination features (eg, heart rate). The respiratory rate was measured for 60 seconds by observing chest wall movements with the child quiet and comfortable.15 Capillary reﬁll was assessed at the ﬁngertip by using a standardized technique.16 Skin turgor was assessed by pinching a small skin fold between the thumb and index ﬁnger on the lateral abdominal wall at the level of the umbilicus.15 Weight gain was recorded at the time of disposition determination or at discharge for admitted children. Percent weight gain was calculated as the difference between discharge and triage weights, divided by the triage weight. Other outcome data recorded included physician willingness to discharge the child at time 2 hours measured by using a Likert scale, the need for hospitalization, and total length of stay (ie, from initiation of intravenous rehydration to ED or hospital discharge). Data were entered into a secure database and double-checked for accuracy by the senior investigator (S.B.F.). real-world model. The secondary outcome was validity. Criterion validity, which is based on a scale’s correlation with an accepted “gold standard,” was assessed by using weight change as a proxy measure for percent dehydration. Construct validity, which reﬂects the scale’s correlation with other measures predicted by theory,13 was evaluated by using parameters thought to be reﬂective of dehydration severity: (1) number of episodes of vomiting and diarrhea before presentation to the ED,17 (2) respiratory rate,15 (3) capillary reﬁll time,15 (4) serum bicarbonate,8,15 (5) serum pH,11 (6) physician assessment of readiness for discharge documented by using a Likert scale, and (7) length of stay.11 Discriminative validity, the ability to discriminate between individuals with a given characteristic/ outcome and those without, was explored for the outcome of hospitalization. The scale’s responsiveness to change was evaluated through comparison of scores before and after intravenous rehydration, a treatment of known efﬁcacy. Outcomes Our primary outcome was the interobserver agreement between 2 independent raters’ CDS scores (ie, reliability). We sought to determine the agreement of (1) individuals with extensive experience and training using the score with (2) individuals with limited training; the latter group representing the Sample Size This study used data collected as part of a clinical trial18 and, as such, is a secondary data analysis. It was estimated post hoc that enrollment of 226 participants would provide 80% power to detect an interobserver correlation as low as 0.35 when the k coefﬁcient under the null hypothesis is 0.20 with signiﬁcance set at .05 (PASS 2008, NCSS, LLC, Kaysville UT). Analysis Characteristics of the study sample were described with frequency counts and percentages for categorical variables; means and SDs or medians and interquartile ranges (IQRs) were used for continuous variables. Dichotomous variables were compared by using the x2 test or Fisher’s exact test. Continuous variables were compared by using the t test or Wilcoxon rank-sum test, as appropriate, depending on data normality. CDS score refers to the total score assigned by the research nurse at treatment initiation; this value was used in all analyses unless otherwise speciﬁed. A P value ,.05 was considered statistically signiﬁcant. Interobserver reliability was evaluated via calculation of the quadratic weighted k statistic (k). Unlike Cohen’s unweighted k, the weighted coefﬁcient considers partial agreement (ie, penalizes disagreement based on degree of divergence) and is recommended when calculating interobserver agreement for ordinal scales.19 Quadratic weighting creates mathematical equivalence with the intraclass correlation coefﬁcient for agreement by using a 2-way random-effects model single-measure reliability.20 Results are interpreted according to the criteria of Landis and Koch,21 in which k values of 0.21 to 0.40, 0.41 to 0.60, 0.61 to 0.80, and .0.80 signify fair, moderate, substantial, and almost perfect agreement, respectively. In assessing validity, associations were quantiﬁed by using the Pearson correlation coefﬁcient (r) or Spearman rank correlation coefﬁcient (r), depending on the distribution of the data. Signiﬁcant outliers, deﬁned as values greater than the 75th percentile plus 1.5 3 the IQR, or less than the 25th percentile minus 1.5 3 the IQR,22 were identiﬁed in PEDIATRICS Volume 129, Number 5, May 2012 Downloaded from pediatrics.aappublications.org by guest on August 22, 2014 e1213 the analysis of criterion validity; hence, this analysis was repeated excluding such values. We also evaluated the CDS’s validity as a dichotomous variable, by using cut points recommended in previous validation studies: scores of ,5 indicate none or some dehydration; those $5 reﬂect moderate to severe dehydration.11,14 In assessing responsiveness to change, CDS scores at time 0, 2, and 4 hours were compared by using the Wilcoxon rank-sum test. Discriminative validity was assessed as the area under the receiver operating characteristic (ROC) curve. Sensitivity, speciﬁcity, positive likelihood ratio, positive predictive value, and negative predictive value were quantiﬁed by using a prespeciﬁed CDS cutoff of $5.11 Because the CDS was developed in a cohort of children ,36 months of age, we analyzed the scale’s performance separately for study participants ,36 and $36 months of age. The CDS’s performance was also evaluated in the subgroup of children with baseline scores $5. All analyses were conducted by using Stata version 9.2 (Stata Corp, College Station, TX). RESULTS A total of 226 children were enrolled (Fig 1); 92 (41%) had moderate/severe dehydration (CDS $5) and 134 (59%) had none/some dehydration (CDS ,5) as assessed by the research nurse. Complete interobserver assessments were performed for 208 participants (92%). Participants who had interobserver assessments completed were similar to those who did not. All partially complete physician scores (n = 7) were lacking a value for the tear category. These patients were older than the remainder of the study sample (4.36 years vs 2.18 years; P = .03). FIGURE 1 Enrollment as it relates to the recording of baseline CDS scores. nurses and physicians (Fig 2). Interobserver agreement, at the level of the individual patient, between trained nurses and the physicians was moderate (k = 0.52; 95% conﬁdence interval [CI] 0.41, 0.63; Fig 3). The k coefﬁcient values for the individual elements of the CDS were as follows: eyes = 0.32 (95% CI 0.18, 0.46), mucous membranes = 0.38 (95% CI 0.26, 0.50), tears = 0.40 (95% CI 0.27, 0.51), and general appearance = 0.49 (95% CI 0.35, 0.60). Reliability was similar for children ,36 and those $36 months of age (k for the total score = 0.51 [95% CI 0.40, 0.65] and 0.53 [95% CI 0.27, 0.68], CDS Reliability The overall CDS distribution was different (P = .002) between research e1214 FIGURE 2 CDS scores in the study population, as assigned by research nurses and physicians (n = 208). The distribution of scores was different between the 2 groups of raters (P = .002). KINLIN and FREEDMAN Downloaded from pediatrics.aappublications.org by guest on August 22, 2014 ARTICLE Compared with those with none/some dehydration (CDS ,5), participants with moderate/severe dehydration (CDS $5) had a greater number of diarrhea episodes before ED presentation, lower serum bicarbonate and pH values at baseline, increased capillary reﬁll time, and increased length of stay in hospital (Table 3). The median physician dischargeability Likert score was higher in the moderate/severe category, indicating a decreased willingness to discharge the children at 2 hours after initiation of intravenous rehydration. FIGURE 3 Scatter-plot diagram comparing research nurse–assigned and physician-assigned CDS scores (n = 208). Marker size is proportional to the number of observations. Solid line represents best ﬁt through the data points. 95% CI –0.18, 0.12). CDS did not correlate with percent weight gain in the subgroup of participants with baseline scores $5 (r = –0.06; 95% CI –0.29, 0.18). Of the variables evaluated to assess construct validity, serum bicarbonate exhibited the strongest correlation with the CDS score (r = –0.35; 95% CI –0.46, –0.23). Subanalysis in participants ,36 months old and in those with moderate/severe dehydration (CDS $5) did not reveal any additional strong correlations. respectively). Reliability in the subgroup with moderate/severe dehydration (CDS $5) was fair (k = 0.30; 95% CI 0.13, 0.45) CDS Validity CDS did not correlate with percent weight gain in the 180 participants for whom discharge weight was available (r = –0.04; 95% CI –0.19, 0.10) (Table 2). The exclusion of 9 values deemed to be outliers did not signiﬁcantly alter the correlation coefﬁcient (Fig 4, r = –0.03; TABLE 2 Correlation Between the Baseline CDS Score and Clinical Markers Reﬂective of Disease Severity Correlation Coefﬁcient (95% CI)a Variable Percent weight gain Vomiting episodesb Diarrhea episodesb Heart rate Respiratory rate Capillary reﬁll time Serum bicarbonate Serum pH Length of stay Physician dischargeability Likert scorec All Participants (n = 226) Age ,36 mo (n = 140) Age $36 mo (n = 86) 20.04 (20.19, 0.10) 0.04 (20.09, 0.17) 0.14 (0.01, 0.27) 0.09 (20.04, 0.22) 0.18 (0.05, 0.30) 0.23 (0.10, 0.35) 20.35 (20.46, 20.22) 20.23 (20.36, 20.10) 0.24 (0.11, 0.36) 0.18 (0.05, 0.31) 20.12 (20.30, 0.07) 0.17 (0.01, 0.33) 0.10 (20.07, 0.26) 0.07 (20.10, 0.23) 0.17 (0.00, 0.32) 0.34 (0.19, 0.48) 20.31 (20.46, 20.15) 20.25 (20.40, 20.08) 0.20 (20.04, 0.36) 0.20 (0.03, 0.35) 0.05 (20.19, 0.28) 20.16 (20.36, 20.06) 0.16 (20.05, 0.36) 20.01 (20.22, 0.20) 0.13 (20.08, 0.34) 0.04 (20.18, 0.25) 20.36 (20.54, 20.16) 20.17 (20.38, 0.06) 0.25 (0.04, 0.44) 0.14 (20.07, 0.34) a Pearson correlation coefﬁcient (serum bicarbonate and serum pH) or Spearman rank correlation coefﬁcient (percent weight gain, vomiting and diarrhea episodes, heart rate, respiratory rate, capillary reﬁll time, length of stay, and physician dischargeability Likert score). b Number of episodes in the 24 hours before ED presentation, as reported by parents/guardians. c Physician willingness to discharge patient at 2 hours after initiation of intravenous rehydration, ranging from 1 (strongly agree that patient is ready for discharge, based on clinical appearance and vital signs) to 5 (strongly disagree that patient is ready for discharge). CDS scores decreased over time after the initiation of intravenous rehydration therapy (Fig 5). Median scores at 2 hours and 4 hours were signiﬁcantly changed from baseline (P , .001 at both time points), indicating responsiveness of the scale to change. For the outcome of hospitalization, the area under the ROC curve was 0.65 (95% CI 0.57, 0.73) (Fig 6). Test characteristics were optimal by using a baseline CDS cut point of $5, which yielded a sensitivity of 62% (95% CI 48, 75), speciﬁcity of 66% (95% CI 58, 73), positive likelihood ratio of 1.8 (95% CI 1.3, 2.4), and negative likelihood ratio of 0.59 (95% CI 0.41, 0.84). Positive predictive and negative predictive values were 35% (95% CI 25, 45) and 85% (95% CI 78, 91), respectively. The CDS scores assigned at 2 and 4 hours after treatment initiation had areas under the curve (AUC) of 0.70 (95% CI 0.62, 0.78) and 0.72 (95% CI 0.64, 0.80) respectively. For participants with baseline scores $5, the area under the ROC curve was 0.53 (95% CI: 0.41, 0.65). Discriminative validity of the baseline CDS did not differ signiﬁcantly between participants ,36 months of age (AUC = 0.66; 95% CI 0.56, 0.76) and those $36 months of age (AUC = 0.60; 95% CI 0.46, 0.75), P = .52. DISCUSSION In this study, the reliability and validity of the CDS10 was evaluated in a cohort PEDIATRICS Volume 129, Number 5, May 2012 Downloaded from pediatrics.aappublications.org by guest on August 22, 2014 e1215 12 11 10 9 8 7 6 5 4 Percent weight gain 3 2 1 0 -1 -2 -3 -4 -5 -6 1 2 3 4 5 6 7 8 CDS score FIGURE 4 Scatter-plot diagram of percent weight gain at the time of ED discharge (y-axis) by CDS score at treatment initiation (x-axis). Black squares indicate median percent weight gain values (n = 171). CDS did not correlate with percent weight gain (r = –0.03; 95% CI –0.18, 0.12). of children with gastroenteritis and dehydration. Interobserver reliability was found to be moderate.21 Although responsiveness to change was detected, no statistically signiﬁcant correlation was identiﬁed between CDS scores and percent weight gain, a proxy measure of ﬂuid deﬁcit. There was a modest correlation with other parameters reﬂective of dehydration severity: episodes of diarrhea, serum bicarbonate and pH, length of stay, and physician willingness to discharge 2 hours after initiation of intravenous rehydration. Similar associations were observed when the CDS’s validity was evaluated as a dichotomous variable by using a cut point of $5. A previous evaluation in children 1 month to 5 years of age found the CDS to be useful in predicting the need for intravenous rehydration and length of stay.11 These ﬁndings were replicated at a different tertiary care center, where an association between CDS score and use of laboratory tests was documented12; however, abnormal results were not signiﬁcantly different across CDS severity assignments. Nonetheless, the authors concluded that the scale is externally valid, and might be useful in guiding therapy (eg, initiation of intravenous rehydration in triage for CDS $5). Their ﬁndings, however, may simply indicate that physicians use the clinical ﬁndings in the CDS to make treatment decisions; not that children with higher CDS scores require that such treatment decisions be made. Hence, it may be inappropriate to conclude that those clinical ﬁndings are necessarily associated with dehydration. In addition, because the assigned CDS score was correlated with the use of intravenous rehydration, it is to be expected that length of stay is prolonged in such patients.23 Both validation studies were further limited by inclusion of few participants with moderate/severe dehydration. Thus, the performance of the CDS could not be evaluated in such children. In the current study, eligibility was deﬁned based on evidence of dehydration sufﬁcient to require intravenous rehydration. Consequently, we were able to evaluate the CDS in a relatively large number of patients with moderate to severe dehydration. Including only children receiving intravenous rehydration eliminates the potential confounding effect of treatment on length of stay. TABLE 3 Characteristics of Study Participants Age, median (IQR), y Male, n (%) Triage weight, median (IQR), kg CTAS score, median (IQR) Vomiting, median (IQR), episodesb Diarrhea, median (IQR), episodesb Heart rate, mean 6 SD, beats per min Respiratory rate, median (IQR), breaths per min Capillary reﬁll time, median (IQR), s Serum pH, mean 6 SD Serum bicarbonate, mean 6 SD, mmol/L Physician dischargeability Likert score, median (IQR)c Length of stay, median (IQR), h Percent weight gain, median (IQR), % All Participants (n = 226) Participants With Moderate/Severe Dehydration (CDS $5) (n = 92) Participants With None/Some Dehydration (CDS ,5) (n = 134) P Valuea 2.21 (1.36, 3.96) 117 (51.8) 12.6 (9.98, 16.2) 3 (2.5, 3) 8 (3, 14) 4 (0, 10) 127 6 20 28 (24, 30) 0.70 (0.56, 1.04) 7.36 6 0.06 18.0 6 3.65 4 (2, 4) 5.41 (4.25, 14.6) 2.24 (0.67, 4.67) 1.96 (1.30, 3.54) 44 (47.8) 11.9 (9.65, 15.7) 3 (2, 3) 8 (4, 14.8) 5 (1.25, 10.8) 126 6 21 28 (24, 32) 0.78 (0.61, 1.20) 7.35 6 0.06 16.3 6 3.34 4 (2, 4) 7.07 (4.67, 25.5) 2.19 (0.65, 4.04) 2.44 (1.41, 4.24) 73 (54.5) 13.1 (10.1, 16.7) 3 (3, 3) 7.5 (3, 13) 3 (0, 8) 130 6 17 28 (24, 30) 0.67 (0.55, 0.88) 7.37 6 0.05 19.2 6 3.39 3.5 (2, 4) 4.88 (4.00, 8.03) 2.27 (0.68, 4.96) .13 .33 .10 ,.001 .83 .05 .15 .02 .001 ,.001 ,.001 .02 ,.001 .53 CTAS, Canadian Triage and Acuity Scale. a P values are for comparison between participants with moderate/severe dehydration versus those with none/some dehydration. b Number of episodes in the 24 hours before ED presentation, as reported by parents/guardians. c Physician willingness to discharge patient at 2 hours after initiation of intravenous rehydration, ranging from 1 (strongly agree that patient is ready for discharge, based on clinical appearance and vital signs) to 5 (strongly disagree that patient is ready for discharge). e1216 KINLIN and FREEDMAN Downloaded from pediatrics.aappublications.org by guest on August 22, 2014 ARTICLE signiﬁcantly inﬂuenced by the treatments provided. A child who receives a large volume of intravenous ﬂuids will gain a signiﬁcant amount of weight before discharge even if he or she was euvolemic at presentation. In an ideal world, the score would have been derived by using serial weights after discharge. 25 FIGURE 5 Scores on the CDS at 30-minute intervals. Time 0 represents the initiation of intravenous rehydration therapy. As in a standard box plot, sample medians are depicted by the center lines of the boxes; the upper and lower limits represent the 75th and 25th percentiles, respectively. Means are superimposed as black squares. Although interobserver agreement was evaluated in the derivation study, it included only 58 paired scores assigned exclusivelybyresearchteam members.10 We evaluated the real-world performance of the CDS by including individuals without extensive training in use of the score. Our ﬁnding of moderate interobserver agreement, whereas the derivation study found substantial agreement (k = 0.77), suggests that the CDS may produce inconsistent results when used by those without formal training. We found, moreover, that even the baseline CDS score assigned by trained nurses was not a clinically useful tool for predicting hospitalization. The AUC did improve, however, when the time 2- and 4-hour CDS scores were used, indicating that the score may have some utility in assessing improvement or predicting hospitalization once treatment is completed.24 The CDS was derived by using weight change as a measure of “true” dehydration status,10 with the assumption that ED discharge weight reﬂects preillness weight. This assumption is questionable, as the ED discharge weight is FIGURE 6 ROC curve for the outcome of hospitalization, based on CDS score assigned at treatment initiation by the research nurse (solid line), 2 hours after treatment initiation (dashed line), and 4 hours after treatment initiation (dotted line); n = 226. AUC is 0.65 (95% CI 0.57, 0.73), 0.70 (95% CI 0.62, 0.78), and 0.72 (95% CI 0.64, 0.80), respectively. Despite these concerns, the derivation10 and validation11,12 studies do show that the CDS can accurately identify children with none/minimal dehydration. Our data caution against the use of the CDS to predict outcomes in children with evidence of dehydration and does not support the authors’ suggestion that laboratory tests and intravenous rehydration be initiated in all children with a CDS .4.12 Such a recommendation would likely result in increased intravenous rehydration use, which is already excessive,26,27 as most children with moderate dehydration can be rehydrated orally.1 Triage nurses should focus on ensuring the success of oral rehydration therapy, as very few children in developed countries have severe dehydration. Furthermore, because vomiting is a major driving force in the use of intravenous rehydration,28 antiemetic agents should be used selectively in children with elevated CDS scores. 29 Several limitations should be recognized. First, this study represents a secondary analysis of data collected as part of an intervention trial.30 Nevertheless, these data were collected prospectively under supervised and standardized conditions. There should not have been bias to the study question, as participants were randomly assigned to treatment groups, thereby balancing the CDS distribution between groups. Second, the study used an untrained individual who was unaware that interobserver agreement was being evaluated. Although this PEDIATRICS Volume 129, Number 5, May 2012 Downloaded from pediatrics.aappublications.org by guest on August 22, 2014 e1217 pragmatic approach is a strength of the study, it may have resulted in physicians assigning scores without paying close attention to the actual values assigned. Finally, we used percent weight gain at discharge as a proxy measure of ﬂuid deﬁcit even though this may not accurately reﬂect dehydration severity; however, as this method was used in the derivation study,10 we expected to ﬁnd a similar correlation. CONCLUSIONS In a cohort of children administered intravenous rehydration secondary to gastroenteritis, the CDS exhibited moderate interobserver reliability and limited criterion, construct, and discriminatory validity. Although previous research has found that it can differentiate children with none/some and moderate/ severe dehydration, our data do not support its use in isolation to make treatment determinations (ie, need for intravenous rehydration) among children with evidence of dehydration. ACKNOWLEDGMENTS We are indebted to the ED nurses, administrative staff, and physicians at The Hospital for Sick Children for their assistance with patient recruitment and adherence to the protocol and to the research nurses for their instrumental role in patient enrollment. REFERENCES 1. King CK, Glass R, Bresee JS, Duggan C; Centers for Disease Control and Prevention. Managing acute gastroenteritis among children: oral rehydration, maintenance, and nutritional therapy. MMWR Recomm Rep. 2003;52(RR-16):1–16 2. National Collaborating Centre for Women’s and Children’s Health. Diarrhoea and vomiting caused by gastroenteritis: diagnosis, assessment and management in children younger than 5 years: Commissioned by the National Institute for Health and Clinical Excellence; April 2009; London, UK. London, UK: RCOG Press; 2009 3. WHO/UNICEF. Joint Statement: Clinical Management of Acute Diarrhoea (WHO/FCH/ CAH/04.07). 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Rapid versus standard intravenous rehydration in paediatric gastroenteritis: pragmatic blinded randomised clinical trial. BMJ. 2011;343:d6976 (Continued from ﬁrst page) PEDIATRICS (ISSN Numbers: Print, 0031-4005; Online, 1098-4275). Copyright © 2012 by the American Academy of Pediatrics FINANCIAL DISCLOSURE: The authors have indicated they have no ﬁnancial relationships relevant to this article to disclose. Dr Freedman previously served as a consultant for Baxter Healthcare. FUNDING: Ms Kinlin received funding from the SickKids Summer Research Program. The original study on which the present article is based was funded by a grant from The Physicians’ Services Incorporated Foundation. PEDIATRICS Volume 129, Number 5, May 2012 Downloaded from pediatrics.aappublications.org by guest on August 22, 2014 e1219 Evaluation of a Clinical Dehydration Scale in Children Requiring Intravenous Rehydration Laura M. Kinlin and Stephen B. Freedman Pediatrics 2012;129;e1211; originally published online April 23, 2012; DOI: 10.1542/peds.2011-2985 Updated Information & Services including high resolution figures, can be found at: http://pediatrics.aappublications.org/content/129/5/e1211.full. html References This article cites 25 articles, 8 of which can be accessed free at: http://pediatrics.aappublications.org/content/129/5/e1211.full. html#ref-list-1 Citations This article has been cited by 1 HighWire-hosted articles: http://pediatrics.aappublications.org/content/129/5/e1211.full. html#related-urls Post-Publication Peer Reviews (P3Rs) One P3R has been posted to this article: http://pediatrics.aappublications.org/cgi/eletters/129/5/e1211 Subspecialty Collections This article, along with others on similar topics, appears in the following collection(s): Emergency Medicine http://pediatrics.aappublications.org/cgi/collection/emergency _medicine_sub Permissions & Licensing Information about reproducing this article in parts (figures, tables) or in its entirety can be found online at: http://pediatrics.aappublications.org/site/misc/Permissions.xh tml Reprints Information about ordering reprints can be found online: http://pediatrics.aappublications.org/site/misc/reprints.xhtml PEDIATRICS is the official journal of the American Academy of Pediatrics. 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