Gastroenteritis

Gastroenteritis and dehydration in children

1. ACUTE GASTROENTERITIS AND DEHYDRATION IN CHILDREN BY ANNE E. ODARO MCM/2017/69852

2. CLINICAL CASE Tina is a 6 month old bottle fed infant, brought to your general practice surgery with a 12 hour history of diarrhea (10 watery green stools without blood) and vomiting (eight yellow non-bilious vomits). Her mother is worried because she is irritable with fever (38°C). Her brother, who attends nursery, has just got over a bout of “gastroenteritis.” She is an active baby with perianal excoriation and a weight of 5.5 kg. She has a sunken fontanel and decreased skin turgor (pinch test 4 sec). She passes urine during the examination. On review of her health record you note she has lost 0.5 kg since last weighed two weeks ago. WHAT IS THE MOST LIKELY DIAGNOSIS?

3. INTRODUCTION Acute gastroenteritis— diarrhoea or vomiting (or both) of more than seven days duration—may be accompanied by fever, abdominal pain, and anorexia. Diarrhoea is the passage of excessively liquid or frequent stools with increased water content. Children with poor nutrition are at increased risk of complications. 

4. EPIDEMIOLOGY It is estimated that there were two billion cases of gastroenteritis that resulted in 1.3 million deaths globally in 2015. Children and those in the developing world are most commonly affected. As of 2011, in those less than five, there were about 1.7 billion cases resulting in 0.7 million deaths, with most of these occurring in the world's poorest nations. Children less than two years of age frequently get six or more infections a year that result in significant gastroenteritis.

5. In 1980, gastroenteritis from all causes caused 4.6 million deaths in children, with the majority occurring in the developing world. Death rates were reduced significantly (to approximately 1.5 million deaths annually) by the year 2000, largely due to the introduction and widespread use of oral rehydration therapy.

6. PATHOPHYSIOLOGY Adequate fluid balance in humans depends on the secretion and reabsorption of fluid and electrolytes in the intestinal tract Diarrhea occurs when intestinal fluid output overwhelms the absorptive capacity of the gastrointestinal tract.

7. The 2 primary mechanisms responsible for acute gastroenteritis are (1) damage to the villous brush border of the intestine, causing malabsorption of intestinal contents and leading to an osmotic diarrhea, and (2) the release of toxins that bind to specific enterocyte receptors and cause the release of chloride ions into the intestinal lumen, leading to secretory diarrhea.  

8. Even in severe diarrhea, however, various sodium-coupled solute co-transport mechanisms remain intact, allowing for the efficient reabsorption of salt and water. By providing a 1:1 proportion of sodium to glucose, classic oral rehydration solution (ORS) takes advantage of a specific sodium-glucose transporter (SGLT-1) to increase the reabsorption of sodium, which leads to the passive reabsorption of water. Rice and cereal-based ORS may also take advantage of sodium-amino acid transporters to increase reabsorption of fluid and electrolytes.  

9. ORGANISMS Viruses (∼70%) Rotaviruses Noroviruses (Norwalk-like viruses) Enteric adenoviruses Caliciviruses Astroviruses Enteroviruses Protozoa (<10%) Cryptosporidium Giardia lamblia Entamoeba histolytica Bacteria (10-20%) Campylobacter jejuni Non-typhoid  Salmonella   spp Enteropathogenic   Escherichia coli Shigella   spp Yersinia enterocolitica Shiga toxin producing  E coli Salmonella typhi  and  S paratyphi Vibrio cholerae Helminths Strongyloides stercoralis

10. CLINICAL PRESENETATION: PATIENT Hx Determine the duration of diarrhea, the frequency and amount of stools, the time since the last episode of diarrhea, and the quality of stools. Frequent, watery stools are more consistent with viral gastroenteritis, while stools with blood or mucous are indicative of a bacterial pathogen. Similarly, a long duration of diarrhea (>14 days) is more consistent with a parasitic or noninfectious cause of diarrhea. Determine if there is an increase or decrease in the frequency of urination as measured by the number of wet diapers, time since last urination, color and concentration of urine, and presence of dysuria .

11. Determine the duration of vomiting, the amount and quality of vomitus ( eg , food contents, blood, bile), and time since the last episode of vomiting. When symptoms of vomiting predominate, one should consider other diseases such as gastroesophageal reflux disease (GERD), diabetic ketoacidosis , pyloric stenosis , acute abdomen, or urinary tract infection. Determine the presence of fever, chills, myalgias , rash, rhinorrhea , sore throat, cough, known immunocompromised status. These may indicate evidence of systemic infection or sepsis.

12. Appearance and behavior: Elements include weight loss, quality of feeding, amount and frequency of feeding, level of thirst, level of alertness, increased malaise, lethargy, or irritability, quality of crying, and presence or absence of tears with crying. Antibiotics: A history of recent antibiotic use increases the likelihood of  Clostridium difficile infection. Travel: History of travel to endemic areas may make prompt consideration of organisms that are relatively rare in the United States, such as parasitic diseases or cholera .

13. PHYSICAL EXAMINATION Elements of the physical examination are as follows: General - Weight, ill appearance, level of alertness, lethargy, irritability HEENT (head, ears, eyes, nose, and throat) - Presence or absence of tears, dry or moist mucous membranes, and whether the eyes appear sunken Cardiovascular - Heart rate and quality of pulses Respiratory - Rate and quality of respirations (deep, acidotic breathing suggests severe dehydration). Back - Flank/ costovertebral angle tenderness increase the likelihood of pyelonephritis

14. Abdomen - Abdominal tenderness, guarding and rebound, and bowel sounds; abdominal tenderness on examination, with or without guarding, should prompt consideration of diseases other than gastroenteritis Rectal - Quality and color of stool, presence of gross blood or mucous Extremities - Capillary refill time, warm or cool extremities Skin - Abdominal rash may indicate typhoid fever (infection with  Salmonella typhi ), while jaundice might make viral or toxic hepatitis more likely; slow return of abdominal skin pinch suggests decreased skin turgor and dehydration, while a doughy feel to the skin may indicate hypernatremia

15. INVESTIGATIONS Random blood sugar – Will most likely be low Hemogram – neutrophilia vs lymphocytosis ; Hemoglobin levels and hematocrit may be low Serum electrolytes – monitor potassium levels Clinically significant electrolyte abnormalities are rare in children with moderate dehydration. Any child being treated with intravenous fluids for severe dehydration, however, should have baseline electrolytes, bicarbonate, and urea/ creatinine values tested. Any child with evidence of systemic infection should have a complete workup, including CBC count and blood cultures. If indicated, urine cultures, chest radiography, and/or lumbar puncture should be performed.

16. IMAGING 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.

17. TREATMENT PLAN A: 10mls/Kg of ORS per loose stool

18. ZINC SULPHATE Dose P.O Zinc sulphate 10mg OD x 2/52 – For <6months P.O Zinc sulphate 20mg OD x 2/52 – For ≥6 months Role Reduces fluid and salt loss in stool by improving mucosal permeability Accelerated regeneration of mucosa Increases levels of brush-border enzymes Enhanced cellular immunity Higher levels of secretory antibodies Improves absorption of ORS

19. ROLE OF DRUGS Drugs are rarely needed. They deal with the symptoms rather than causes of disease and may distract from the use of appropriate fluid therapy.  Antibiotics are not indicated in viral or uncomplicated bacterial gastroenteritis and may cause harm. In non-typhoid  Salmonella  infections antibiotics increase the risk of prolonged carriage and disease relapse.  Treating gastroenteritis due to Shiga toxin producing  E coli  with antibiotics may increase the risk of haemolytic uraemic syndrome.

20. Antibiotics are required, however, for bacterial gastroenteritis complicated by septicaemia and in cholera, shigellosis, amoebiasis , giardiasis , and enteric fever. Antidiarrhoeal and antiemetic agents are not recommended for routine use because of the risk of adverse effect. Ondansetron does not have extrapyramidal effects and reduces the duration and frequency of vomiting, but also increases diarrhea Loperamide decreases the duration of diarrhea, but has potential severe adverse effects and evidence that benefits outweigh potential harms is lacking

21. PREVENTION: HAND WASHING

22. PREVENTION

23. SUMMARY Rotavirus is the most common cause of acute gastroenteritis worldwide and vaccination will have a major impact on disease rates, morbidity, and mortality Most children are not dehydrated and can be managed at home Dehydration, metabolic acidosis, and electrolyte disturbance can be prevented and treated by fluid therapy Most children with mild-moderate dehydration can be treated with oral or enteral rehydration using low osmolality oral rehydration solutions

24. Severely dehydrated or shocked children usually need intravenous fluids and hospital admission Drugs are usually unnecessary and may do harm General practitioners have an important role in prevention, through encouraging breastfeeding, recommending and advocating free access to rotavirus vaccination, and educating carers about personal and food hygiene

25. Unanswered research questions in acute gastroenteritis How safe and effective is home based care for children with mild-moderate dehydration? What role do food based oral rehydration solutions have in developed communities? What is the role and safety of new generation antiemetics and antidiarrhoeal agents? What is the role of zinc supplementation in well nourished children? Do probiotics have a role as adjuvant therapy, and what type, dose, and regimen is optimal?

26. REFERENCES   Singh, Amandeep (July 2010).  "Pediatric Emergency Medicine Practice Acute Gastroenteritis — An Update" . Pediatric Emergency Medicine Practice.  7   Meloni , A; Locci , D; Frau, G; Masia , G; Nurchi , AM; Coppola, RC (October 2011). " Epidemiology and prevention of rotavirus infection: an underestimated issue?".   Journal of Maternal-Fetal and Neonatal Medicine .  24  ( Suppl 2): 48–51.  doi : 10.3109/14767058.2011.601920 .  PMID   21749188 . Ruben AR, Fisher DA. The casemix system of hospital funding can further disadvantage Aboriginal children.  Med J Aust  1998;169(8 suppl ):S6-10. [ PubMed ]  Elliott EJ, Peadon E. Expert commentary on Alhashimi D, Alhashimi H, Fedorowicz Z. Antiemetics for reducing vomiting related to acute gastroenteritis in children and adolescents.  Cochrane Database Syst Rev Evidence-Based Child Health 2006;(3):CD005506. [ PubMed ]

27. THANK YOU! QUESTIONS?