2.1. Assesment Define the problem Flashcards
Differentiate vomiting with 2 things
It is very important to differentiate vomiting from regurgitation. It is also important to differentiate the vomiting animal from one that has a productive cough and gags after coughing. This is often confused with vomiting by owners
Tools for investigating vomiting
Variety of diagnostic tools, including clinical pathology,
diagnostic imaging, endoscopy and exploratory laparotomy.
Usual location of regurgitation, maybe other, and tools (2)
When regurgitation is the predominant clinical sign, it will usually be due to oesophageal disease (very occasionally pharyngeal) and usually carries a poor or guarded prognosis due to the type of lesion – for
example foreign body, stricture or megaoesophagus. The patient should not be treated symptomatically without diagnostic investigation
to define the lesion where possible. In addition, the investigation of regurgitation essentially involves visualising the oesophagus (by endoscopy and/or diagnostic imaging tools)
Gagging 2 regions, tool, plus sign
Similarly, the patient who is gagging most likely has a lesion in the pharyngeal region or upper oesophagus, and visualising the lesion is the appropriate diagnostic path. Clearly, the animal that is coughing has respiratory or cardiac disease and requires an entirely different diagnostic approach.
Clues to help the differentiation
- Vomit (4)
- Regurgitation exacerbated (3)
- Character of the material expelled (3)
As discussed, vomiting is a neurologically coordinated activity with defined stages and physical manifestations. The patient will exhibit abdominal effort before bringing up the material, and vomiting is often preceded by hypersalivation – manifested by licking of lips and repeated swallowing (which are signs of nausea). The vomiting may be projectile. In contrast, regurgitation is a passive process – there are no coordinated movements. It is often induced or exacerbated by alterations in food consistency and exercise and facilitated by gravity when the head and neck are held down and extended. Animals that
regurgitate will often gag as the material accumulates in the pharynx.
The character of the material expelled may also give the clinician clues. While undigested food may be brought up by vomiting or
regurgitation, if the food is partially digested and/or contains bile, the patient is vomiting and not regurgitating. The pH of the vomitus is
occasionally, but not always, useful. Acidic material strongly suggests vomiting, but pH neutral material may be the product of either vomiting or regurgitation.
Regurgitation and cough
As mentioned, because the epiglottis does not close, regurgitating patients are at considerable risk of aspirating gastric contents. Thus, if
an owner reports that his/her animal developed a cough at the same time it starts ‘vomiting’, the clinician should be alert to the possibility
that aspiration has occurred and that this is more likely to occur with regurgitation than vomiting.
2 caveat
There is a caveat, however, which should be kept in mind. Patients who have experienced serious vomiting of acidotic gastric contents may develop a secondary oesophagitis and present with signs suggestive
of both vomiting and regurgitation. Usually, vomiting will have been the first sign noted. Animals that ingest caustic or irritant material
causing oesophagitis and gastritis may also present with signs of both vomiting and regurgitation.
Regurgitation primary or secondary
In contrast, regurgitation is almost always due to primary oesophageal disease
Primary GI examples
Primary GI diseases are those where there is specific primary GI pathology such as gut disturbance due to dietary indiscretion, inflammation, infection, parasites, obstruction or neoplasia. There may be
metabolic consequences of the GI disease, but the primary pathology is in the GI tract.
Secondary GI examples
Secondary GI disease is where the vomiting or regurgitation has occurred due to pathology elsewhere in the body – the gut is just the ‘messenger’. Abnormalities of other body systems may indirectly cause vomiting either due to the action of toxins on the CRTZ,
vomiting centre and vestibular system or by stimulation of peripheral non-GI-associated vomiting receptors. Examples would include renal failure, liver disease, ketoacidososis, pancreatitis, hypercalcaemia, hypoadrenocorticism and other metabolic disorders. In most cases, there is no pathology identifiable in the gut, or where there is, for example ulceration secondary to liver or renal disease or hypoadrenocorticism,
the primary cause is the metabolic disorder.
Symtomatic treatment of primary GI
It is also important to appreciate that there are cases of primary GI disease causing vomiting such as gastroenteritis caused by ingestion of spoiled food or other irritants that can be safely treated symptomatically, as the cause is transient and will resolve within days without
specific treatment. Symptomatic management such as withholding food, antiemetic treatment and/or dietary change is appropriate for these patients.
The uncommon secondary GI causes of regurgitation all cause
megaesophagus (Table 2.1), so the clinical decision pathway leading to their diagnosis begins with the diagnosis of megaoesphagus endoscopy or diagnostic imaging and then the search for a metabolic
cause. As mentioned, symptomatic treatment of regurgitation without establishing the cause is not prudent.
Clues to - Primary GI disease (5) + exceptions examples
Primary GI disease should be strongly suspected if:
• an abnormality is palpable in the gut, for example foreign body and intussusception;
• the vomiting is associated with significant diarrhoea;
• the patient is clinically and historically normal in all other respects;
• the onset of vomiting significantly preceded any development of signs of malaise – depression and/or anorexia;
• the vomiting is consistently related in time to eating (although this can also occur with pancreatitis).
It is important to note, however, that primary GI disease cannot
be ruled out even if none of the aforementioned features is present.
For example, vomiting may be delayed for some hours (up to 24 h) in animals with non-inflammatory gastric disorders. Animals with foreign bodies or secretory disorders of the bowel often vomit despite not
eating. In lower bowel disorders, vomiting more commonly occurs at variable times after eating.
Animals with primary GI may also be depressed and inappetant due to the lesion (there are neural inputs to the satiety centre in the hypothalamus from the gut) or due to the secondary effects of prolonged vomiting such dehydration or electrolyte disturbances. Usually, the malaise will occur at the same time or after the onset of
vomiting.
Thus, the features in the aforementioned bulleted list are strong clues that primary GI disease is present, but their absence does not preclude it.
Clues to Secondary GI disease (4)
Animals with secondary GI disease are vomiting due to the effect of toxins on the vomiting centre or CRTZ or because of the stimulation of non-GI-associated peripheral receptors. The vomiting is usually unrelated to eating – except pancreatitis in dogs.
Animals with secondary GI disease will:
• Often have evidence from the history and/or clinical examination of abnormalities affecting other organ systems, for example jaundice, polydipsia/polyuria.
• Vomiting is usually intermittent, unrelated to eating and may often occur subsequent to the onset of other signs of malaise.
• In general, animals that are vomiting due to extra-GI disease are metabolically ill and are not usually bright, alert and happy.
• If a patient has been metabolically ill (depressed and inappetant) for a significant period before vomiting was observed, then secondary
GI disease is most likely.
Secondary clue regurgitation + exception
Secondary GI causes of regurgitation will frequently have other systemic signs such as generalised weakness or metabolic malaise. It
is usually only patients with megaoesophagus due to focal myasthenia gravis who present with regurgitation as their only clinical sign.
