Nausea And Vomiting
Nausea and vomiting , two intensely disagreeable symptoms may occur singly or concurrently and may be due a wide variety of factors. The pathophysology of vomiting is not completely understood. Vomiting appears to involve 2 functionally distinct medullary centers: the vomiting center, which controls and initiates the act of vomiting and the chemoreceptor trigger zone, which is activated by many drugs and different kinds of toxins. The vomiting center may receive stimuli from the alimentary tract, from the brain, from the vestibular apparatus (see motion sickness), and from the chemoreceptor trigger zone.
- Alimentary disorders: irritation, inflammation, or mechanical disturbance at any level of the gastrointestinal tract.
- Hepatic, biliary and pancreas disorders
- Central nervous system disorders: increased intracranial pressure, stroke, migraine, infection, toxins, radiation sickness.
- Motion Sickness
- Endocrine Disorders: diabetic acidosis, adrenocortical crisis, pregnancy, starvation, lactic acidosis
- Genitourinary disorders: uremia, infection, urinary obstruction
- Cardiovascular disorders: acute myocardial infarction, congestive heart failure
- Drugs: morphine, meperidine, anesthetics, chemotherapy, alcohol
- Psychologic disorders: reaction to pain, fear or displeasure chronic anxiety reaction, anorexia nervosa.
Complications of vomiting include fluid and electrolyte disturbances (dehydration), pulmonary aspiration of vomitus, gastroesophageal mucosal tear, malnutrition, rupture of esophagus.
Simple acute vomiting such as occurs following dietary or excessive alcohol consumption, or during morning sickness of early pregnancy, may require little or no treatment. Avoiding known aggravating factors and taking simple corrective dietary measures usually suffice.
Severe and prolonged nausea and vomiting usually require carefull medical management in the hospital. Attempt to determine and correct the causes of the vomiting as soon as possible. The vomiting patient will be checked if aspiration has occurred. The following general measures may be used as adjuncts to specific or surgical treatment.
Fluids And Nutrition
Mentain adequate hydration and nutrition, and any electrolyte disturbance will be corrected as soon as it occurs. Hypokalemia and metabolic alkalosis are common in patients with severe vomiting. The food will be temporarily withhold and 5% dextrose in saline with appropriate KCL supplementation. If vomiting continues, a nasogastric tube to intermittent suction for gastric decompresion. When oral feeding is resumed, begin with dry foods in small quantities like salted crackers, graham crackers. With morning sickness these foods may best be taken before arising. Later, frequent small feedings or simple paltable foods. Hot beverages like tea and cold beverages like iced tea are tolerated quite early. Avoid lukewarm beverages, and always consider what kind of food you would like to eat.
All unnecessary drugs should be withheld from pregnant woman during the early critical early phase of fetal development. Unless nausea and vomiting of pregnancy are severe and progressive, avoid using medication for vomiting. The possible teratogenic effects of may classes of drugs may harm the pregnancy. Antiemetic drugs are usually better for preventing vomiting, nut they may be emplyed selectively if the cause of vomiting cannot be treated effectively. The drugs should be used cautiously to avoid masking of a severe illness. The choice of drug treatment depends on the causes of vomiting.
Sedatives, alone or with anticholinergics, may be helpful in patients with psyhogenic vomoting.
Antihistamines like Dimenhydrinate may be useful for patients with vestibular disorders (motion sickness)
Phenothiazines like prochlorperazine is prefered vor vomiting caused by drugs, radiation vomiting, or surgery.
Metoclopramide, is particularly helpful for diabetic gastroparesis vomiting and preventing nausea and vomiting of cancer chemotherapy.
Vomiting Medical Measures
- Sedation with any of the common sedative drugs can be effective.
- Stimulation of the nasopharynx – a soft catheter is introduces nasally to stimulate the pharynx and is often successful.
- Local anesthetics
- Antispasmodics – atropine sulfate
- Amyl nitrite inhalations may also be effective
Vomiting Surgical Measures
Various phrenic nerve operations, including bilateral phrenicotomy, may be indicated in extreme cases that fail to respond to all other measures and are considered to be a threat to life.