1-Vomiting, also
known as emesis, puking, barfing, throwing up, among other terms, is the
involuntary, forceful expulsion of the contents of one's stomach through the
mouth and sometimes the nose.
2-Vomiting can
be caused by a wide variety of conditions; it may present as a specific
response to ailments like gastritis or poisoning, or as a non-specific sequela
of disorders ranging from brain tumors and elevated intracranial pressure to
overexposure to ionizing radiation. The feeling that one is about to vomit is
called nausea, which often proceeds, but does not always lead to, vomiting.
Antiemetics are sometimes necessary to suppress nausea and vomiting. In severe
cases, where dehydration develops, intravenousfluid may be required.
Self-induced vomiting can be a component of an eating disorder, such as bulimia
nervosa, and is itself now an eating disorder on its own, purging disorder.
Complications
1-Aspiration
2-Dehydration
and electrolyte imbalance
3-Dentistry
Recurrent
vomiting, such as observed in bulimia nervosa, may lead to destruction of the
tooth enamel due to the acidity of the vomit. Digestive enzymes can also have a
negative effect on oral health, by degrading the tissue of the gums.
4-Receptors on
the floor of the fourth ventricle of the brain represent a chemoreceptor
trigger zone, known as the area postrema, stimulation of which can lead to
vomiting. The area postrema is a circumventricular organ and as such lies
outside the blood–brain barrier; it can therefore be stimulated by blood-borne
drugs that can stimulate vomiting or inhibit it.
Contents
Gastric
secretions and likewise vomit are highly acidic. Recent food intake appears in
the gastric vomit. Irrespective of the content, vomit tends to be malodorous.
The content of
the vomitus (vomit) may be of medical interest.
1-
Fresh
blood in the vomit is termed hematemesis ("blood vomiting"). Altered
blood bears resemblance to coffee grounds (as the iron in the blood is
oxidized) and, when this matter is identified, the term coffee-ground vomiting
is used.
2-
If
the vomiting reflex continues for an extended period with no appreciable
vomitus, the condition is known as non-productive emesis or "dry
heaves", which can be painful and debilitating.
Color of vomit
1-Bright red - bleeding from the esophagus
2- Dark red vomit with liver-like clots
suggests profuse bleeding in the stomach, such as from a perforated ulcer
3- Coffee-ground-like
vomit suggests less severe bleeding in the stomach,
4-Yellow vomit suggests bile,
indicating that the pyloric valve is open and bile is flowing into the stomach
from the duodenum (this is more common in older people)
Differential
diagnosis
Vomiting may be
due to a large number of causes, and protracted vomiting has a long
differential diagnosis.
Digestive tract
• Gastritis (inflammation of the
gastric wall)
• Gastroenteritis
• Gastroesophageal reflux disease
• Celiac disease
• Non-celiac gluten sensitivity
• Pyloric stenosis (in babies, this
typically causes a very forceful "projectile vomiting" and is an
indication for urgent surgery)
• Bowel obstruction
• Overeating
• Acute abdomen and/or peritonitis
• Ileus
• Food allergies (often in conjunction
with hives or swelling)
• Cholecystitis, pancreatitis,
appendicitis, hepatitis
• Food poisoning
• In children, it can be caused by an
allergic reaction to cow's milk proteins (Milk allergy or lactose intolerance)
Causes in the
sensory system:
• Movement: motion sickness (which is
caused by overstimulation of the labyrinthine canals of the ear)
• Ménière's disease
Causes in the
brain:
• Concussion
• Cerebral hemorrhage
• Migraine
• Brain tumors, which can cause the
chemoreceptors to malfunction
• Benign intracranial hypertension and
hydrocephalus
Metabolic
disturbances
(these may irritate both the stomach and the parts of the brain that coordinate
vomiting)
• Hypercalcemia (high calcium levels)
• Uremia (urea accumulation, usually
due to renal failure)
• Adrenal insufficiency
• Hypoglycemia
• Hyperglycemia
Pregnancy:
• Hyperemesis, morning sickness
Drug reaction
• Alcohol
• opioids
• selective serotonin reuptake
inhibitors
• many chemotherapy drugs
• some entheogens (such as peyote or
ayahuasca)
• Norovirus (formerly Norwalk virus or
Norwalk agent)
• Swine influenza
• Bulimia Nervosa
• Purge disorder
Emetics
An emetic, such
as syrup of ipecac, is a substance that induces vomiting when administered
orally or by injection.
·
Salt
water and mustard water have been used since ancient times as emetics.Care must
be taken with salt, as excessive intake can potentially be harmful.
·
Copper
sulfate was also used in the past as an emetic. It is now considered too toxic
for this use.
·
Hydrogen
peroxide is used as an emetic in veterinary practice.
Other types
Projectile vomiting refers to
vomiting that ejects the gastric contents with great force. It is a classic
symptom of infantile hypertrophic pyloric stenosis, in which it typically
follows feeding and can be so forceful that some material exits through the
nose.
Treatment
An
antiemetic is a drug that is effective against vomiting and nausea. Antiemetics
are typically used to treat motion sickness and the side effects of medications
such as opioids and chemotherapy.
Antiemetics
act by inhibiting the receptor sites associated with emesis. Hence,
1-anticholinergics,
2-antihistamines,
3-dopamine
antagonists,
4-serotonin
antagonists, and cannabinoids
Epidemiology
Nausea and/or
vomiting are the main complaints in 1.6% of visits to family physicians in
Australia.
