Introduction
Nausea is an uneasy or unsettled feeling in the stomach
together with an urge to vomit. Nausea and vomiting, or
throwing up, are
not diseases
.
They
can be symptoms
of many different conditions.
These include :
morning sickness during pregnancy, infections,
migraine headaches, motion sickness,
food poisoning,
cancer chemotherapy or other medicines. others
Introduction
Nausea and vomiting are common. Usually, they are
not serious.
BUT IF the following cases occur immediate
referral is recommended
Vomited for longer than 24 hours
Blood in the vomit
Severe abdominal pain
Headache and stiff neck
Pathophysiology
Nausea and vomiting consist of three stages:
1. Nausea, : nausea is the subjective feeling of a need to vomit. It is often accompanied by autonomic symptoms such as pallor, tachycardia,
diaphoresis, and salivation
2. Retching, which follows nausea, consists of diaphragm, abdominal wall, and chest wall contractions and spasmodic breathing against a closed glottis. Retching can occur without vomiting, but this stage produces the pressure gradient needed for vomiting, although no gastric contents are expelled.
3. Vomiting, or emesis, is a reflexive, rapid, and forceful oral expulsion of upper gastrointestinal contents due to powerful and sustained contractions in the abdominal and thoracic musculature.1 Vomiting, like nausea, can be
accompanied by autonomic symptoms.
note :
Regurgitation, unlike vomiting, is a passive process without involvement of the abdominal wall and diaphragm wherein gastric or esophageal contents move into the mouth. in patients with gastro esophageal reflux disease (GERD), one
hallmark symptom is acid regurgitation.
Pathophysiology
Various areas in the brain and the
gastrointestinal (GI) tract are stimulated
when the body is exposed to noxious
stimuli (e.g., toxins), gastro-intestinal
irritants (e.g., infectious agents), or
chemotherapy.
These areas include :
the chemoreceptor trigger zone (CTZ) in the
area postrema of the fourth ventricle of the brain,(
outside BBB
-???)serotonin type 3
(5-HT3), neurokinin-1 (NK1), and
dopamine (D2) receptors.
the vestibular system (H1,M)
visceral afferents from the GI tract (5-HT3 R ), the cerebral cortex.
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Chemoreceptor trigger zone (CTZ) (5-ht3, D2, NK!)
Gastrointestinal visceral
afferents
(5ht3, D2, NK1)
Cerebral cortex
(sensory input )
Vestibular system
(H1, Muscarinic)
Central
vomiting
centers
(medulla)
Stimulation of
salivation &
respiratory
centers,
pharyngeal ,
GI, Abdominal
muscle
contraction
Nausea &
vomiting
Physiologic pathways that result in nausea and vomiting. 5-HT3, serotonin type 3 receptor; D2, dopamine type 2 receptor; GI, gastrointestinal; H1, histamine type 1 receptor, NK1, neurokinin-1. (Adapted from American Society of Health-System Pharmacists. ASHP therapeutic guidelines on the pharmacologic management of nausea and vomiting in adult and pediatric patients receiving
chemotherapy or radiation therapy or undergoing surgery
CTH, TOXINS
Motion,
CTH, INFECTIONSEmotional
causes
Pathophysiology
Motion sickness is caused by stimulation of the vestibular system. This area contains many histaminic (H1) and muscarinic cholinergic
receptors.
The higher brain (i.e., cerebral cortex) is affected by sensory input
such as sights, smells, or emotions that can lead to vomiting. This area is involved in anticipatory nausea and vomiting associated with
chemotherapy.
Nausea and vomiting can be classified as either simple or complex. Simple nausea and vomiting occurs occasionally and is either
self-limiting or relieved by minimal therapy. It does not have detrimental effects on hydration status, electrolyte balance, or weight because it is short-lived.
complex nausea and vomiting requires more aggressive therapy because
electrolyte imbalances, dehydration, and weight loss may occur. Unlike simple nausea and vomiting, complex nausea and vomiting can be
caused by exposure to noxious agents.
Rubenstein ED, et al Cancer J 2006
Neuroanatomical
Centers:
Emetic center
Chemoreceptor trigger zone
Vagal afferents of GI
Neurotransmitters:
Dopamine (DA)
Serotonin (5HT)
Substance P
GABA
Cannabinoid I
Acetylcholine
Endorphins
Emetic CenterCTZ
Assessment & Interpretation
Nature & severity
Projectile vomiting
:
babies pyloric stenosis ,
Adults with history of peptic ulceration
(usually duodenal ).
Sour smelling vomit
possible obstruction
(e.g. pyloric stenosis)
Blood stained vomit
(hematemesis)
Blood may appear:
fresh & bright red, or dark with clotted appearance If blood originates in the stomach , it will be
degraded by gastric acid producing a dark colored vomit with a coffee ground appearance
Frequent vomiting for more than 24-
48hr.
Deteriorating
nausea ,
increased
incidence of vomiting
over a longer
period of time
Sudden vomiting without nausea
is a
characteristic of a central cause (e.g.
Cerebral tumor or injury),
Nausea preceding vomiting
indicates a
gastrointestinal cause.
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Accompanying symptoms
Abdominal pain
may cause
reflex vomiting
as in:
paroxysmal coughing
can lead to vomiting .
Other disorders may lead to vomiting include
Ménière’s
disease & acute pain in extra abdominal body system
(glaucoma)
Gastroenteritis
:
Diarrhea accompanying vomiting
suggests ,
usually due to ingestion of some dietary insult or
to infection or food
food poisoning :
Recent travelers to hot countries should
be referred to eliminate dysentery &
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─ liver disease
─ appendicitis ,
─ biliary colic
Central nervous disorder (e.g. space occupying
lesions, meningitis , head injury & subdural hemorrhage )
Migraine
attacks.
Anxiety
or an emotional disturbance
anorexia nervosa & bulimia
.
Note:
Episodic or chronic vomiting accompanied by weight loss
requires referral for investigation of the cause .
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If the cause can be elicited, the decision of whether to refer or not becomes easier
Common dietary cause are hot or spicy foods , over indulgence of food or
alcohol , & sensitivity to certain foods (e.g.. Sea food , pork…). such case will usually resolve spontaneous within 24 hrs.
Many drugs can cause nausea & vomiting (e.g. NSAIDS, colchicine , digoxin in
toxic doses, Fe , levodopa , theophylline , estrogens & cytotoxic drugs )
Motion is a common cause of N&V, & in severe cases may persist for a day or
2 after the journey
Infection may cause vomiting , especially otitis media in children & the early
stages of various viral illness(measles). Condition affecting the abdomen may result in reflex vomiting.
Heart failure , particularly right sided HF may result in congestion of the
abdominal organs with blood , giving a sensation of nausea & sometimes vomiting.
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Episodes of vomiting which may sometimes be severe, in
patients with diabetes , require immediate referral to exclude
loss of
control of the diabetes
.
Chronic
alcoholic
patients may suffer from early morning
vomiting
2 types of vomiting may occur in pregnancy :
The familiar syndrome of morning sickness comprises regular bouts of
short lived N or V or both during the 1st few weeks of pregnancy. it may
occur at any time of the day . It usually resolve spontaneously around the 3rd month of pregnancy . Drugs should not be recommended but reassurance , frequent small meals , rest , and bed rest in the morning are sensible recommendation .
A more sever form of vomiting which may occur in early pregnancy Is
hyperemesis gravidarum , it may lead to dehydration & shock & requires medical referral
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Risk factors in children
Vomiting in children is usually self remitting but
certain points should be remembered
Many babies regurgitate their milk after meal
(posseting) & mothers should be assured that
this is normal
However , in cases of projectile vomiting (baby
may be alert & appear normal OR in babies who
appear distressed, irritable or very
drowsy)referral is required
Children over 2 years of age require referral if
they have vomited for more than 24hrs
If the cause of vomiting has been identified or is
suspected, the underlying disorder should be
attended to as a priority
Management :
Non pharmacologic
Pharmacologic
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Management
Non pharmacologic management
General Measures:
resting the stomach
avoid strong perfumes
evaporation of mint may be helpful
sit in an upright position for 30 - 45 minutes after eating
Avoiding drinking milk or eating heavy or fatty warm, very spicy and
odorous meals for 24 hrs.
Sips of tasteless drinks, ideally water, should be taken regularly to
prevent dehydration
Food should be avoided until the patients feels hungry (start with bread
toast or plain biscuits )
If tolerated , intake may be increased carefully till a normal diet is
tolerated
Administration of fluids and electrolytes
Acupuncture and acupressure
There are indications that acupuncture and/or
acupressure (in the form of pressure massage or a special wristband) are effective in the case of nausea and vomiting, particularly after surgery and after chemotherapy.
Complementary therapies and psychological
techniques
for psychogenic factors (anxiety and stress) and conditioning (anticipatory nausea and vomiting) play an important role.
These types of nausea and vomiting respond poorly to antiemetics.
These techniques act through relaxation, distraction, and/or a feeling of self-control.
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Non pharmacologic management
P6 (Neiguan) point
Pharmacologic drug treatment
There are few oral drugs available to treat vomiting attacks
Both antihistamines & anti muscarinic drugs may be useful
to prevent attacks , especially of motion sickness.
Anti histamine such as cinnarizine , diphenhydramine &
promethazine which also possess anticholinergic properties
, may be useful , but should be used in caution in patients
with glaucoma , prostatitis , constipation & those who
drive.
Note:
Babies and young children should be given oral rehydration
fluid that replace glucose , Na , K lost during vomiting . Glucose enhance the absorption of electrolytes across the inflamed mucosa .
The use of proprietary rehydration fluids in children should be
encourage over home remedies to prevent inappropriate load of Na , & K
Drug Class Information
Antacids
magnesium hydroxide, aluminum hydroxide, and/or calcium carbonate,
relieve N&V, (through gastric acid neutralization.)
Histamine-2 Receptor Antagonists
cimetidine, famotidine, nizatidine, ranitidine N&V associated with
heartburn or GERD .
Antihistamine–Anticholinergic Drugs
treatment of simple symptomatology.
Adverse reactions that may be apparent with the use of the antihistaminic–
anticholinergic agents primarily include drowsiness or confusion, blurred vision, dry mouth, urinary retention, and possibly tachycardia, particularly in elderly patients.
Phenothiazines “ chlorpromazine , promethazine ”
Phenothiazine are most useful in patients with simple nausea and
vomiting.
dangerous side effects, including extrapyramidal reactions, hypersensitivity
reactions with possible liver dysfunction, marrow aplasia, and excessive sedation.
Metoclopramide
Metoclopramide increases lower esophageal sphincter tone, aids gastric
emptying, and accelerates transit through the small bowel, possibly through the release of acetylcholine.
Metoclopramide is used for its antiemetic properties in patients with
diabetic gastroparesis and with dexamethasone for prophylaxis of delayed nausea and vomiting associated with chemotherapy administration.
Corticosteroids
Dexamethasone has been used successfully in the management of
chemotherapy- induced nausea and vomiting (CINV) and postoperative nausea and vomiting (PONV), either as a single agent or in combination with selective serotonin reuptake inhibitors (SSRIs). For CINV,
dexamethasone is effective in the prevention of both Cisplatin-induced acute emesis and when used alone or in combination for the prevention of delayed nausea and vomiting associated with CINV.
Selective Serotonin Receptor Inhibitors (Ondansetron, Granisetron, Dolasetron, and Palonosetron)
SSRIs (dolasetron, granisetron, ondansetron, and palonosetron) act by blocking
presynaptic serotonin receptors on sensory vagal fibers in the gut wall.
The most common side effects associated with these agents are constipation, headache,
and asthenia
Cannabinoids
When compared with conventional antiemetics, oral nabilone and oral dronabinol were
slightly more effective than active comparators in patients receiving moderately emetogenic chemotherapy regimens.
The efficacy of cannabinoids as compared to SSRIs for CINV has not been studied. They
should be considered for the treatment of refractory nausea and vomiting in patients receiving chemotherapy.
Substance P/Neurokinin 1 Receptor Antagonists
Substance P is a peptide neurotransmitter in the NK family whose preferred receptor is the
NK1 receptor. Substance P is believed to be the primary mediator of the delayed phase of CINV and one of two mediators of the acute phase of CINV.
Aprepitant is the first approved member of this class of drugs and is indicated as part of a
multiple drug regimen for prophylaxis of nausea and vomiting associated with high-dose cisplatin-based chemotherapy.
Numerous potential drug interactions are possible; clinically significant drug interactions
with oral contraceptives, warfarin, and oral dexamethasone have been described.
