Emesis and Sputum Flashcards
Define Emesis and its significance
Vomiting (emesis)- the forceful movement and elimination of the contents of the stomach by the constant action of the abdominal muscles with the opening of the gastric cardia.
The presentation may be acute or chronic and range from mildly annoying symptoms to a condition that impairs the patients’ quality of life or is a marker of a life-threatening disease, emotional distress, memory (defensive) or an adverse reaction to treatments.
What are the most frequent and severe effects of vomiting?
- Dehydration
- Nutritional deficiencies
- Electrolyte and acid-base imbalance
Why is the pathophysiology for vomiting complex? What centres are involves and how?
The act of emesis is associated with 2 main centres located in the medulla oblongata (the brain stem)
• the vomiting centre
• the chemoreceptor trigger zone (CTZ)
Vomiting is ultimately controlled by the vomiting centre which receives input from a wide range of sources. Some of these inputs are directly connected to the vomiting centre but most are directed via the CTZ.
The CTZ is an area of the brain not fully separated from the blood by the blood brain barrier so it can detect chemicals in the blood and cerebrospinal fluid and initiate vomiting. The CTZ is also stimulated by signals from the gut and inner ear.
what is the CTZ?
- AKA Chemoreceptor zone
- The CTZ is an area of the brain not fully separated from the blood by the blood brain barrier so it can detect chemicals in the blood and cerebrospinal fluid and initiate vomiting. The CTZ is stimulated by signals form the gut and inner ear.
what are the main 2 mechanisms for emesis?
1) neurological stimulation where the medulla oblongata “senses” noxious chemical agents (like poison, chemotherapy agents and (Digoxin) which then causes nausea and the emesis reflex.
- Diseases based on the CNS like infections and tumours can also stimulate nausea etc.
2) Peripheral diseases like diseases in the Gastrointestinal tract. Brain centres where nausea is perceived will stimulate vomiting.
- Tumours etc and drugs in the periphery may cause local dysfunction in diff organs that when sensed can cause vomiting
Examples of toxins that can trigger Emesis?
- Medications/drugs (e.g. cytoxics, opiods, NSAIDs, antibiotics, anticonvulsants, iron and many others)
- Poisoning
- Substance Abuse
Examples of Metabolic conditions can trigger Emesis?
- Hypercalcaemia
- Hyponatremia
- Ketoacidosis
Examples of Organ failure / disorders of viscera that can lead to Emesis?
- Liver
- Renal
- Obstruction (e.g. gastric outlet, bowel, biliary, pancreatic)
- Severe constipation
- Gastroparesis
- Inflammation or irritation (e.g. gastroenteritis, hepatitis, cholecystitis, NSAID, chemotherapy, radiation)
- Malignancy
- Ascites
Examples of Neurological conditions that can lead to vomiting?
- Increased intracranial pressure (e.e malignancy, haemorrhage, cranial irradiation or abscess)
- Meningeal infiltration
- Vestibular (e.g. labyrinthitis or effects of medications or drugs)
- Anxiety
- Pain
what is Nausea?
Subjective experience of feeling sick, Unpleasant feeling, often leading to vomiting.
what is retching?
Movements associated with vomiting without the expulsion of gastrointestinal contents.
what is Haematemesis?
- Presence of blood in vomit, bright pink or ‘coffee ground’
what is Copraemesis?
Odour or presence of faeces in vomit
what is Emesis/vomiting?
Forceful emptying of stomach contents through the mouth
what is Anticipatory nausea and vomiting?
Where a person has emetic symptoms to a conditioned stimulus before treatment is commenced
what is Emetogenic potential?
Ability of a treatment, eg chemotherapy, to cause nausea, retching and vomiting