Gastroenteritis Flashcards
Gastroenteritis
Inflammation caused by infection of the stomach and small intestines. It can be caused by a virus or bacteria, and can be acute or chronic
Types of viruses causing gastroenteritis
Rotavirus, norovirus
Types of bacteria causing gastroenteritis
E-coli, salmonella, campylobacter
Faecal-oral transmittion
Faeces in undigested waste that doesn’t get absorbed into the system. It can be contaminated by the pathogen and then gets passed on
Reasons for transmission
Close interaction with infected people, contaminated food and water, practising poor hygiene habits
Four stages of contamination
Ingestion, invasion, destruction, malfunction
Ingestion
Pathogens enter the body via contaminated food/drink, close interaction with infected people and poor hygiene.
Invasion
The pathogen directly invades the GI wall as the epithelial cells contain all the enzymes the virus needs to multiply. They are used to produce viral proteins and nucleic acid which form new viruses and can leave the cell to spread further
Destruction
Pathogens continue the destruction of the muscosal lining of the bowel wall causing malfunction of digestive and absorptive functions.
Malfunction
Toxins stimulate the secretion of fluid and electrolytes in the lumen. The inflammation causes exudation of fluid and cells, the intestines become overwhelmed and loose their ability to reabsorb, increasing peristaltic movements and gastric motility
Symptoms of gastroenteritis
Nausea, vomiting, diarrhoea, abdominal pain, fever, dehydration, lethargy, oligura and anuria
Oligura
Urine output less than 1ml/kg/hour
Anuria
Failure of the kidneys to produce urine
Treatment of gastroenteritis
Oral rehydration therapy, nasogastric tube, IV fluids, practice hand washing
Oral rehydration therapy
Encourage fluid intake, disencourage the drinking of juice and carbonated drinks and offer oral rehydration salt solutions
Nasogastric tube
May be used if clinically dehydrated, vomiting persistently or refusing fluids
IV fluids
If shock is suspected, clinically dehydrated or deteriorating
Why are antibiotics not given
They will not cure a virus, so are not routinely given
Why does gastroenteritis cause nausea and vomiting?
Due to the slower movement of the food through the stomach. Nerves send signals to contract the muscle lining of the stomach
Why does gastroenteritis cause diarrhoea?
The pathogens cause the cells to die meaning the epithelial wall is unable to absorb fluids and nutrients. Toxins stimulate the production of more fluid which have to be excreted.
Why does gastroenteritis cause dehydration?
Due to a severe loss of fluid, salts and minerals through vomiting and diarrhoea and the loss of ability to absorb fluids in the epithelial wall
