Validity and Reliability of Clinical Signs in the Diagnosis of Dehydration in Children

Abstract

ABSTRACT. Objective. To determine the validity and reliability of various clinical findings in the diagnosis of dehydration in children.Design. Prospective cohort study.Setting. An urban pediatric hospital emergency department.Participants. One hundred eighty-six children ranging in age from 1 month to 5 years old with diarrhea, vomiting, or poor oral fluid intake, either admitted or followed as outpatients. Exclusion criteria included malnutrition, recent prior therapy at another facility, symptoms for longer than 5 days' duration, and hyponatremia or hypernatremia.Methods. All children were evaluated for 10 clinical signs before treatment. The diagnostic standard for dehydration was fluid deficit as determined from serial weight gain after treatment.Main Results. Sixty-three children (34%) had dehydration, defined as a deficit of 5% or more of body weight. At this deficit, clinical signs were already apparent (median ‫؍‬ 5). Individual findings had generally low sensitivity and high specificity, although parent report of decreased urine output was sensitive but not specific. The presence of any three or more signs had a sensitivity of 87% and specificity of 82% for detecting a deficit of 5% or more. A subset of four factors-capillary refill >2 seconds, absent tears, dry mucous membranes, and ill general appearance-predicted dehydration as well as the entire set, with the presence of any two or more of these signs indicating a deficit of at least 5%. Interobserver reliability was good to excellent for all but one of the findings studied (quality of respirations).Conclusions. Conventionally used clinical signs of dehydration are valid and reliable; however, individual findings lack sensitivity. Diagnosis of clinically important dehydration should be based on the presence of at least three clinical findings. Pediatrics 1997;99(5). URL: http://www. pediatrics.org/cgi/content/full/99/5/e6; dehydration, capillary refill, clinical assessment, interobserver agreement.

Systematic review and validation of prediction rules for identifying children with serious infections in emergency departments and urgent-access primary care.

“…Poor peripheral circulation was noted in six studies, with a LR+ ranging from 2.39 to 38.8. 11,29,50,68,69,72 There did not appear to be a clear relationship between the prevalence of infection in the study setting and LR+. Rapid breathing and shortness of breath provided greatest LR+ in the single low-prevalence study, 11 with a LR+ of 9.3-9.7.…”

“…Three studies used an outcome of meningitis, [70][71][72] of which two included children with first episode of fever and seizures, 70,71 and one based on signs of meningeal irritation. 72 Two studies used an outcome of gastroenteritis causing dehydration, 68,69 one of which included children with clinical gastroenteritis 68 and the other children with diarrhoea with or without vomiting and evidence of dehydration. 69 Two studies used an outcome of pneumonia, 73,74 and included febrile children and children with clinical signs of respiratory infection.…”

“…Finally, a single rule was identified for dehydration from gastroenteritis, which provided modest LR+ (6.10) and LR-(0.24) from a single high-prevalence study. 68 …”

Recommended management of diarrhoea and vomiting

“…10 However, combinations of examination signs provide more reliable results than any individual sign. 11 The WHO has classified dehydration into none, mild to moderate and severe. 3 Table 2 shows how this is assessed clinically.…”

“…This requires hospitalisation, and is not without risk, eg phlebitis, iatrogenic hyponatraemia. 11 A recent Cochrane review looked at the outcome for oral vs intravenous rehydration for treating mild-moderate dehydration due to gastroenteritis in children. It concluded that there was no important difference, especially if low osmolarity solutions were used.…”