Vomiting Is One of the Commonest Symptoms of Illness and Presentation to the ED

VOMITNG

Introduction

Vomiting is one of the commonest symptoms of illness and presentation to the ED.

It is also one of the most non-specific.

It is commonly an early sign of illness, occurring before more localizing signs and symptoms develop.

A clear diagnosis may not be able to be made in the ED when patients present early in their illness.

The causes are “legion” and range from benign to life threatening. It is for this reason that all cases of vomiting need careful clinical assessment.

In particular this clinical assessment must take note of any:

●Concerning associated clinical features

●Associated risk factors

Treatment is of course directed at the cause of the vomiting; however this will not always be apparent early in the course of an illness.

Careful assessment of a patient’s risk factors as well as taking note of any concerning features will therefore be essential, and if there are serious concerns, then a period of observation in hospital will be necessary, even when the diagnosis is unclear.

A common mistake made in diagnosis with patients who are vomiting without obvious cause is to label them as “gastroenteritis”.

Gastroenteritis usually has associated watery diarrhea, and if a patient does not have this, the index of suspicion for an alternative diagnosis must be raised.

Pathophysiology

The causes of vomiting are virtually limitless – pretty much any systemic illness can result in this symptom.

In many cases the cause will be readily apparent following clinical assessment by history and examination, however on other occasions the cause may not be so apparent. When the diagnosis is not immediately clear, a systematic approach to clinical assessment will be important because of the wide range of differential diagnoses.

A careful consideration of the each of the major categories of causes of vomiting will be necessary.

These include:

1.Gastrointestinal:

Medical causes:

●eg, gastroenteritis, IBD, peptic ulcer disease, pancreatitis, biliary tract disease, GORD.

Surgical causes:

●eg, mechanical bowel obstruction, appendicitis, diverticulitis, cholycystitis, mesenteric ischemia.

2.Infectious disease:

●Gastroenteritis(from a wide range of pathogens).

●Virtually any systemic infection, the more serious (such as meningococcemia) are more likely to cause early vomiting.

3.Metabolic:

Any serious metabolic derangement, including:

●DKA

●Metabolic acidosis

●Renal failure, (uraemia)

●Liver failure (ammonia and other toxic metabolites).

●Hypercalcemia, (especially in patients with malignant disease).

4.Toxicological:

●Drug overdose

●Drug toxicity.

●Alcohol

●Poisons

●Venoms

●Radiation poisoning (for patients receiving radiotherapy or where a particular occupational risk for this exists).

5.Neurological:

●Raised intracranial pressure.

This is an important group, and one that is not uncommonly missed as a cause of vomiting.

The earliest sign of raised intracranial pressure (of any cause) will often be unexplained vomiting.

Often the patient is given an initial diagnosis of “gastro”. If there is no clear history of diarrhea, fever, contact with a known case etc, then this diagnosis cannot be confidently applied. If there is a significant history of associated headache the possibility of raised intracranial pressure needs to be kept in mind.

●Vertigo (of any cause) or motion sickness.

●Migraine headache (and variants).

6.Pregnancy:

●This must be considered in any woman of child bearing age!

7.Cardiac:

●Nausea and vomiting is not uncommonly associated with ACS.

This diagnosis is usually quickly apparent on the history of associated chest pain; however the situation may not be so clear cut in patients who are unable to clearly communicate.

8Severe pain in general.

●Common associations with vomiting include: renal colic, biliary colic, glaucoma, torsion of testes.

9.Psychogenic:

●Eating disorders

●Anxiety syndromes

●Emotional distress

●Other psychosomatic pathology.

Complications

Vomiting in its own right may have serious, even life-threatening complications, quite apart from its underlying cause.

These include:

1.Dehydration:

●Hypovolemia.

2.Electrolyte and glucose disturbances:

●Hyernatremia/ hyponatremia

●Hypokalemia

●Hypomagnesemia

●Hypoglycaemia

3.Pre-renal impairment or failure:

●Particularly in those with pre-existing renal disease.

●The most immediate concern may then be hyperkalemia (rather than hypokalemia).

3.Mallory-Weis tears of the oesophagus.

●With consequent bleeding.

4.Inability to take oral medications

Clinical Assessment

Important points of history

Specific questioning should include:

1.Medications, (is the vomiting a toxic effect of the drug?)

Most commonly:

●Opioids

●Digoxin

●Theophylline

●Lithium

●Chemotherapy, (presumably this would be volunteered by the patient).

2.The possibility of drug overdose.

●This may not always be volunteered.

●It may not even be recognized that this is the cause of the symptoms when the effects are delayed, the classic example being paracetamol overdose.

3.Exposure to possible environmental toxins.

4.Pregnancy in women of child bearing age.

●Keep in mind that the patient response “I cannot be pregnant”, (unless the woman has had a hysterectomy), does not necessarily exclude this possibility!

5.Recent unexplained persistent headache:

●Consider the possibility of raised intracranial pressure.

6.Severe myalgias, (possibility of underlying systemic sepsis).

Important points of examination:

Concerning associated clinical features include:

1.Vital signs

●Fever (especially without clear focus)

●Circulatory compromise

2.Alterations in conscious state.

3.Extreme lethargy/ malaise

4.Signs of dehydration

5.Purpuric rashes:

●Serious sepsis (meningococcus, pneumococcus, haemophilus species)

Risk Factors:

When assessing patients for vomiting certain important risk factors must always be kept in mind.

Associated risk factors include:

1.Very young or the elderly.

2.Recent contact with patients with serious infectious disease.

3.Those with impaired immunity, (from any cause – occult sepsis should always be kept in mind)

4.Those with impaired ability to effectively communicate.

5.Significant comorbidities:

Chronic disease:

●eg: renal or hepatic failure.

Patients with malignant disease:

●The possibility of cerebral metastases or hypercalcemia must be considered.

Investigations

In clear cut presentations no investigation may be required.

In cases where the patient appears unwell and/ or the diagnosis is not clear, then some investigation may be necessary to look for an underlying cause and to rule out secondary complications of the vomiting.

The extent and type of investigation undertaken in a patient who presents with vomiting will depend on:

●The degree of vomiting

●How unwell the patient appears

●Risk factors the patient may have

●The index of suspicion for any given condition.

The following may be considered:

1.Blood tests:

●FBE

●CRP

●U&Es/ glucose

●Lipase

●LFTs

●ABGs

●Calcium.

●Pregnancy test.

2.ECG

3.Urine for micro and culture:

●Particularly in the very young or the elderly.

4.Plain radiology:

●AXR/CXR for evidence of mechanical obstruction.

5.CT scan brain:

●If raised intracranial pressure is suspected.

Other specific tests are done according the index of clinical suspicion for any given pathology, for example:

●Drug levels: e.g. Digoxin levels/ Paracetamol levels/ theophyline levels.

●Alcohol levels.

●Specific toxin or poison screens (heavy metals for example)

●CT scan/ endoscopy for investigation of gastrointestinal tract disease.

Management

Treatment is of course directed at the underlying cause of the vomiting.

With regard to the symptom and the complications of vomiting itself, treatment will consist of:

1.Resuscitation:

●IV fluids as required.

2.Correction of electrolyte disturbances:

●Hypokalemia in particular

3.Anti-emetics:

Nausea has a wide range of treatment options. The most commonly prescribed include:

Major tranquillizing class agents:

●Prochlorperazine

●Metoclopramide

Serotonin antagonists:

●Ondansetron

●Granisetron

Condition specific agents:

Some specific conditions are helped by specific agents, for example:

●B6 in mourning sickness.

●Dexamethasone in some cases of chemotherapy induced nausea and vomiting.

Disposition

One of the most important considerations in the management of the vomiting patient where the cause is uncertain will be the disposition of the patient.

Discharge may be appropriate with GP or ED review providing:

●The patient is not unwell

●The patient does not have significant risk factors

●Investigations, where done, are normal.

Admission to a hospital ward or short stay unit however may be necessary in some cases.

Note that there does not “have to be a diagnosis” before admission can occur!The diagnosis is simply “vomiting for investigation”.

Reasons for admission can include:

1.Unwell patients who require ongoing resuscitation, (fluids and electrolyte replacement).

2.To establish a diagnosis with further specialized investigations, especially in patients with significant risk factors.

For the very young and the elderly the threshold must at least be low.

4.When patients are unable to tolerate any oral fluids.

5.When important medications are required by the patient who cannot take them orally.

Dr J. Hayes

24 June 2010