Introduction
Diarrhoea caused by acute gastroenteritis (AGE) is a significant health problem with an estimated 1.7 billion cases occurring annually. It is the third leading cause of mortality in children under five years of age, accounting for 9% of all deaths worldwide in this age group.1 In Myanmar, it is one of the leading causes of under-five mortality.2 According to the Myanmar Demographic Health Survey (MDHS), one in ten under-five children experienced diarrhoea illness within two weeks before their survey.3
AGE is an inflammation of the gastrointestinal tract caused by various viruses, bacteria, or parasites. Its clinical course typically lasts 3 to 8 days and can present with symptoms ranging from mild to severe diarrhoea, often accompanied by fever, nausea, vomiting, abdominal cramps, and dehydration.4 Diarrhoea and vomiting result in the loss of water and electrolytes, leading to dehydration and electrolyte imbalances. If not corrected timely, these conditions can progress to acute renal failure and other serious complications. Given this understanding, clinicians routinely order Urea and Electrolytes (U&E) tests to assess patients with AGE.
In 2023, AGE was a leading cause of hospitalization, representing approximately 13% of in-patient admissions at Parami General Hospital (PGH). Additionally, over 8,000 U&E tests were ordered for both out-patients and in-patients, contributing significantly to the laboratory workload. Based on our experience, although U&E tests increase the workload for clinical and laboratory staff and impose a substantial cost on patients’ families, clinically significant results from these tests are rare in AGE patients. As a result, a considerable proportion of the ordered U&E tests in these cases do not contribute meaningfully to patient care in clinical practice.
Therefore, we did this audit as an ad hoc initiative to determine the usefulness of U&E test in managing the children with AGE. We conducted a retrospective review of electronic records for AGE patients admitted in December 2023. The aim was to determine the proportion of U&E test orders, and that of urea and electrolyte abnormalities, and the frequency of changes in treatment plans based on U&E results in AGE patients. We anticipate that the findings of this study could support the development of hospital guidelines for the selective and rational ordering of laboratory tests in the management of acute gastroenteritis (AGE) cases.
Materials and methods
It was a retrospective study on electronic records. The data of children (<12 years) admitted during December, 2023, and discharged with a diagnosis of AGE were recorded. Data were extracted from the PGH database: age, sex, hospital stay, underlying disease, clinical presentations, dehydration status, and treatment given. Serum urea and electrolytes (sodium, potassium, chloride, bicarbonate) results from blood samples taken before intravenous rehydration therapy were collected from enclosed reports of investigations. Persistent vomiting was defined as vomiting two times or more per day.5 Hydration status was defined as no dehydration (well, alert, normal eyes, drinks normally, not thirsty, skin pinch goes back quickly), some dehydration (any 2 of restless, irritable, sunken eyes, thirsty/drinks eagerly, skin pinch goes back slowly) and severe dehydration (any 2 of lethargic or unconscious, sunken eyes, drinks poorly/ not able to drink, skin pinch goes back very slowly). Need for rehydration therapy with maintenance plus deficit was also considered as presence of dehydration if the clinical signs and symptoms were not fully recorded. Abnormalities of urea and electrolytes were defined as follows: High blood Urea (Urea Nitrogen >6.8 mmol/L), Na <130 mmol/L), Hypernatremia (Na>150 mmol/L), Hypokalemia (K< 3.5 mmol/L), Hyperkalemia (K>5 mmol/L), Hypochloremia (Cl <98 mmol/L), Hyperchloremia (Cl > 106 mmol/L) and Acidosis (HCO3 <15 mmol/L).6-8 U&E test ordering was determined as useful if electrolyte abnormalities altered the given treatment, in managing the children with AGE. The data were analyzed by using IBM SPSS version 25.
Results
Sixty-one children were included in the analysis; 34 (55.7%) boys and 27 (44.3%) girls with median age of 3.2 years (range: 0.8 – 11 years). Median hospital stay of the patients was 3 days (range: 1-5 days). Clinical and laboratory parameters and need for IV rehydration therapy of the patients on admission are described in Table 1.
Table 1. Proportion of Clinical parameters, laboratory tests done and need for IV rehydration therapy of patients on admission
Among 61 patients, U&E test (Urea, Na, K, Cl, HCO3) was ordered in 50 (82.0%) cases and Na and K only test was ordered in 2 (3.3%). Frequency of Urea and Electrolytes tests done among AGE patients with different dehydration status was described in Table 2.
Table 2. Frequency of Urea & Electrolytes (Na, K, Cl, HCO3) tests done among AGE patients with different dehydration status
The ranges of the test results among children with AGE were: Urea: 1 – 8 mmol/l, Na: 131-150 mmol/l, K: 3.4 – 5.2 mmol/l, Cl: 96-121 mmol/l, HCO3: 8.3-23.4 mmol/l. Status of Urea and electrolytes among AGE patients with different dehydration status is described in Table 3.
Table 3. Urea and electrolytes status among AGE patients with different dehydration status
Discussion
U&E tests are commonly ordered by medical officers in hospital settings. This study questioned the need for routine urea and electrolytes testing in hospitalized children with AGE. High serum urea level was reported as one of the specific tests to assess severe dehydration in patients. Hoxha et al suggested a serum urea level of 11 mmol/L as a severe dehydration cut-off point.9 In this study, only one patient exceeded normal urea level and had serum urea 8 mmol/L; the child was hospitalized due to excessive vomiting for 1 day with hypoglycemia and no clinical symptom of dehydration. He recovered after correction of hypoglycemia and IV rehydration with maintenance therapy and had only one day of hospital stay.
In this study, no cases of hyponatremia and hypernatremia according to the cut-off (<130 and >150 mmol/L) by the Myanmar Paediatric Society Guideline were detected. Some studies reported a certain proportion of hypo- and hypernatremia as the cut-off above and beyond 135-145 mmol/L. However, many cases with sodium 130-135 mmol/L and 145-150 mmol/L do not need special correction of sodium and usually respond with ORS or IV rehydration therapy for AGE.
In this study, there was only one case each for hypokalemia (3.4 mmol/L) and hyperkalemia (5.2 mmol/L), however, these patients had no specific complications and the values were just below and above the cut-off points. Therefore, the results cannot be considered as clinically significant as these cases did not require special treatment.
This study’s most common findings were Hyperchloremia and metabolic acidosis (39.2% and 31.4%). Previous studies also reported a high proportion of these abnormalities among children with acute gastroenteritis: 62.9% hyperchloremia (Cl>108mmol/L) and 84.6% acidosis (HCO3 <18 mmol/L) in under 5 children in Nigeria, 53.8% of hyperchloremia in children younger than 18 years in Pakistan.10,11 In gastroenteritis, hyperchloremic metabolic acidosis or normal anion gap acidosis is a common presentation, in which loss of HCO3 due to diarrhoea is matched by an approximately equivalent increase in the serum chloride concentration.12 IV rehydration therapy for dehydration or shock with a large quantity of chloride-containing fluid can also be a cause of this type of metabolic acidosis: however, this cannot be a reason in our cases because the electrolytes tests of the children were done before IV rehydration. The treatment for hyperchloremic acidosis is rehydration with isotonic fluid. Since the children in this study were in-patients, over 90% of patients needed IV rehydration therapy either for dehydration or poor oral intake due to excessive vomiting. Therefore, oral or IV rehydration therapy had already been given before the results came out, which took approximately 4 hours after sending the sample. There was no mortality in our study and all the patients recovered with ORS or IV dextrose saline or Normal Saline or Ringer Lactate which was given in accordance with the clinical assessment of dehydration status. Hence, HCO3 and Cl results did not add any more useful information for the clinicians beyond the clinical information. Our results are in line with previous studies which reported that appropriate rehydration in children with AGE will resolve many electrolyte abnormalities quickly and safely.13,14
In a review of laboratory audits, inappropriate tests requested by clinicians were reported to be 5% to 95%.15 In this study, medical officers requested U&E for more than 80% of the patients with AGE. As in a private hospital where many patients are considered to afford the charges, there may be patients’ pressure for proactive testing and clinicians might practice defensive medicine by ordering laboratory tests for all patients to avoid any litigation issue. In PGH, each U&E test costs approximately 50,000 kyats, potentially placing a significant financial burden on the patient’s family and contributing to increased healthcare costs. Overutilization of laboratory tests can also waste manpower and chemical resources of the hospital, especially in a developing country like Myanmar.
This study has limitations such as the retrospective nature, conducted in a single center and small sample size. The findings in this study might not reflect the situations in Government hospitals where patients might have more severe clinical conditions before arriving at the hospital. As our study was based on a small number of AGE patients, especially with very few severe dehydration cases, we cannot set specific factors that can guide the practitioners to order urea and electrolytes testing. However, the result of this study indicated that U&E tests should not be ordered routinely in AGE cases with no or some dehydration. As common sense, we suggest doing U&E tests in children with AGE who are ill, who had severe dehydration, and had higher underlying medical conditions.
Conclusion
In our study, no changes to patient treatment plans were required based on the U&E test results. Metabolic acidosis is a common finding in children with AGE and can be effectively managed with appropriate rehydration therapy based on clinical judgment. Routine ordering of U&E tests is not justified in children admitted to a private hospital with AGE, particularly in cases with no or some dehydration.
References
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Author Information
Saw Win, Win Lai May, May Thet Tun, Eaint Thinzar Myint, Ei Shwe Sin Win
1. Consultant Paediatrician, Parami General Hospital
2. Research Advisor, Parami General Hospital
3. Senior Medical Officer, Parami General Hospital
4. Senior Medical Officer, Parami General Hospital
5. Officer Manager, Parami General Hospital
