Pediatric Gastroenteritis in Emergency Medicine Workup

Updated: Oct 17, 2017
  • Author: Adam C Levine, MD, MPH; Chief Editor: Kirsten A Bechtel, MD  more...
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Laboratory Studies

The vast majority of children presenting with acute gastroenteritis do not require serum or urine tests, as they are unlikely to be helpful in determining the degree of dehydration. In a meta-analysis of 6 studies, only serum bicarbonate (< 17) had statistically significant positive and negative likelihood ratios for detecting moderate dehydration. [2]

Clinically significant electrolyte abnormalities are rare in children with moderate dehydration. However, any child being treated with intravenous fluids for severe dehydration should have baseline electrolytes, bicarbonate, and urea/creatinine drawn. Laboratory tests are also indicated in patients with moderate dehydration whose history and physical examination are inconsistent with straightforward gastroenteritis.

Fecal leukocytes and stool culture may be helpful in children presenting with bloody diarrhea or recent travel to a low-resource setting. Children older than 12 months of age with a recent history of antibiotic use should have stool tested for C difficile toxins. Those with a history of prolonged watery diarrhea (>14 d) or travel to an endemic area should have stool sent for ova and parasites.

Any child with evidence of systemic infection should have a complete workup, including CBC and blood cultures. If indicated, urine cultures, chest radiography, and/or lumbar puncture should be performed.


Imaging Studies

Abdominal films are not indicated in the management of acute gastroenteritis. If the clinician suspects a diagnosis other than acute gastroenteritis based on history and physical examination findings, appropriate imaging modalities should be pursued.

A study looked to determine the predictive value of ultrasonography (US) for appendicitis in children when combined with clinical assessment based on the Pediatric Appendicitis Score (PAS). The study concluded that ultrasound findings in children with possible appendicitis should be integrated with clinical assessment, such as a clinical score, to determine next steps in management. Rates of false-negative US increase with increasing PAS, and false-positive US results occur more often with lower PAS. When discordance exists between US results and the clinical assessment, serial examinations or further imaging are warranted. [27]  While ultrasound of the inferior vena cava to aorta ratio has been shown to be associated with overall volume status in children, a recent large study did not find it sensitive or specific enough to use as an independent tool for the diagnosis of dehydration in children with diarrhea. [28]


Other Tests

Workup of acute gastroenteritis should begin by using elements of the history and physical examination to determine level of dehydration. Both the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) recommend using a simple dehydration scale to classify the total body water loss occurring with dehydration as minimal/none (< 3%), mild/moderate (3-9%), or severe (>10%) [11] (see Table 1 below). The World Health Organization (WHO) recommends a simpler system for use by both physicians and lay health workers, which classifies dehydration as none, some, or severe [7] (see Table 2 below).

One meta-analysis of 13 separate studies looking at individual signs and symptoms of dehydration found only abnormal capillary refill (>2 sec), decreased skin turgor, and abnormal respiratory pattern (hyperpnea) had statistically and clinically significant positive and negative likelihood ratios for detecting dehydration in children. [2]

Several studies have found that combinations of clinical signs and symptoms may have better sensitivity and specificity for detecting dehydration in children than individual signs or symptoms. [3, 4, 5, 6, 2] Parkin et al validated an 8-point scale termed the Clinical Dehydration Scale (CDS) that assigns 0-2 points each to general appearance, sunken eyes, mucous membranes, and tears (Table 3). [3] In a cohort of children presenting to a North American emergency department, a score of 5-8 on this scale had a positive likelihood ratio of 5.2 and a negative likelihood ratio of 0.55 for the presence of moderate/severe dehydration in children with acute gastroenteritis.

Recently, the Dehydration: Assessing Kids Accurately (DHAKA) Score was validated in a large cohort of children presenting to an urban hospital in South Asia and found to be more accurate and reliable than the WHO algorithm (Table 4). [29] A DHAKA score of 2 or more had 93% sensitivity for detecting any dehydration in children under five with diarrhea and a DHAKA score of 4 or more had 86% sensitivity for detecting severe dehydration.

Table 1. Assessment of Dehydration* (Open Table in a new window)

Symptom or Sign No or Minimal Dehydration Mild to Moderate Dehydration Severe Dehydration
Mental status Alert Restless, irritable Lethargic, unconscious
Thirst Drinks normally Drinks eagerly Drinks poorly
Heart rate Normal Normal to increased Tachycardia
Quality of pulses Normal Normal to decreased Weak or impalpable
Breathing Normal Normal or fast Deep
Eyes Normal Slightly sunken Deeply sunken
Tears Present Decreased Absent
Mouth and tongue Moist Dry Parched
Skin fold Instant recoil Recoil < 2 seconds Recoil >2 seconds
Capillary refill Normal Prolonged Prolonged or minimal
Extremities Warm Cool Cold, mottled, cyanotic
Urine output Normal Decreased Minimal
*Adapted from King et al. MMWR Recomm Rep. 2003;52(RR-16):1-16. [11]

  Table 2. Assessment of Dehydration According to the World Health Organization* (Open Table in a new window)

Severe Dehydration Two of the following signs:

-Lethargic or unconscious

-Sunken eyes

-Not able to drink or drinking poorly

-Skin pinch goes back very slowly

Some Dehydration Two of the following signs:

-Restless, irritable

-Sunken eyes

-Thirsty, drinks eagerly

-Skin pinch goes back slowly

No Dehydration Not enough of the above signs to classify as some or severe dehydration
*Adapted from World Health Organization. [7]


Table 3:

Clinical Dehydration Scale (Open Table in a new window)

General Appearance Normal Thirsty, restless, or irritable Lethargic or unconscious
Eyes Normal Slightly sunken Very sunken
Mucous Membranes Moist Dry Very dry
Tears Tears present Decreased tears Absent tears

Adapted from Parkin PC, Macarthur C, Khambalia A, Goldman RD, Friedman JN. Clinical and laboratory assessment of dehydration severity in children with acute gastroenteritis. Clin Pediatr (Phila). 2010 Mar;49(3):235–9.


Dehydration: Assessing Kids Accurately (DHAKA) Score (Open Table in a new window)

Clinical Sign Finding Points
General Appearance Normal 0
Restless/irritable 2
Lethargic/unconscious 4
Tears Normal 0
Decreased 1
Absent 2
Skin Pinch Normal 0
Slow 2
Very slow 4
Respirations Normal 0
Deep 2

Total: ≥4 severe dehydration, 2-3 some dehydration, 0-1 no dehydration

Adapted from: External Validation of the DHAKA score and comparison to the current IMCI algorithm for the assessment of dehydration in children with diarrhoea. Lancet Global Health. 2016 Oct;4(10):e744-51.