Retching
| Retching | |
|---|---|
| Specialty | Gastroenterology |
Retching(also known asdry heaving) is the reverse movement (retroperistalsis) of thestomachandesophaguswithoutvomiting.[1]It can be caused by bad smells or choking, or by withdrawal from certain medications, or after vomiting has completed. Retching can also occur as a result of an emotional response or fromstress,which produces the same physical reaction. The function is thought to be mixinggastric contentswith intestinal refluxate in order to buffer the former and give it momentum in preparation of vomiting.[2]Treatments include medication and correction of thefluidandelectrolyte balance.
Physiology
[edit]The retching phase is characterized by a series of violent spasmodicabdomino-thoraciccontractions with theglottisclosed. During this time, the inspiratory (inhalatory) movements of the chest wall anddiaphragmare opposed by the expiratory contractions of the abdominal musculature. At the same time, movements of thestomachand its contents take place. Whereas a patient will complain of disagreeable sensations duringnausea,speech is not possible during retching. The characteristic movements furnish a ready diagnostic sign of the retching phase. Schindler (1937)[3]studied retching on two occasions duringgastroscopyand noted that longitudinal folds appeared in the previously smoothantrum,thickened quickly, came together and completely closed the antrum.[4]Retching involves a deep inspiration against a closedglottis.This, along with contraction of the abdomen, leads to a pressure difference between the abdominal and thoracic cavities. As a result, the stomach and gastric contents are displaced upwards toward the thoracic cavity.[5]
Retching comprises a rhythmically alternating (about once per second) elevation and descension of the entire pharyngolaryngo-esophago-gastric apparatus in synchrony with the movement of the diaphragm. The function of retching may be to mix gastric contents with intestinal refluxate to buffer gastric contents before gastroesophageal reflux and to impart a momentum to the gastric contents before vomiting. Airway protection during retching is accomplished by glottal closure during retches and constriction of theupper esophageal sphincterbetween retches.[2]
Versus vomiting
[edit]Vomiting (the expulsion of gastric contents) is usually preceded by retching, but retching and vomiting can occur separately[6]and involve different sets of muscles.[7]During a retch,thoracic pressureisdecreasedand abdominal pressure isincreased,which may serve to position gastric contents and overcome esophageal resistance.[6]Conversely, a vomit occurs withincreasedthoracic and abdominal pressure. Retches and vomits are commonly lumped together in behavioral analyses and consequently the neural controls for these processes are not well delineated.[8]
Treatments
[edit]The treatments for significant retching include correction of fluid and electrolyte balance, nutritional support and medications likephenothiazines(such asCompazineandPhenergan),5-HT3 antagonist(such asZofran),dopamine receptor antagonists(such asReglan),antihistamines(Antivert,Dramamine,Benadryl) andanticholinergics(scopolamine). Alternative approaches are also available. The best-studied alternative therapy is perhaps the use ofacupressurefor pregnancy-related nausea and vomiting.[citation needed]Wristbands with acupressure buttons are commercially available. An implanted device with attached electrodes into the gastric wall can be an option for patients with refractory nausea and vomiting.[9]
See also
[edit]- Pharyngeal reflex,the gag reflex
- Regurgitation (digestion)
- Vomiting
References
[edit]- ^"Vomiting and Nausea".eMedicine.February 12, 2012.
- ^abLang, IM; Dana, N; Medda, BK; Shaker, R (September 2002). "Mechanisms of airway protection during retching, vomiting, and swallowing".American Journal of Physiology. Gastrointestinal and Liver Physiology.283(3): G529-36.doi:10.1152/ajpgi.00062.2002.PMID12181164.
- ^Schindler, R (1937).Gastroscopy.Chicago: University of Chicago Press. p. 145.
- ^Keet, AD (1998). "Nausea, Retching, and Vomiting".The Pyloric Sphincteric Cylinder in Health and Disease.PLiG. p. 122.
- ^Berne, Robert M.; Matthew N. Levy (2004).Physiology.Elsevier Mosby. p. 557.ISBN0-323-03390-3.
- ^abAndrews, PL; Davis, CJ; Bingham, S; Davidson, HI; Hawthorn, J; Maskell, L (February 1990). "The abdominal visceral innervation and the emetic reflex: pathways, pharmacology, and plasticity".Canadian Journal of Physiology and Pharmacology.68(2): 325–45.doi:10.1139/y90-047.PMID2178756.
- ^Grelot, L; Miller, AD (1994)."Vomiting - Its Ins and Outs".News in Physiological Sciences.9(3): 142–147.
- ^Horn, Charles (11 October 2007)."Why is the neurobiology of nausea and vomiting so important?".Appetite.50(2–3): 430–434.doi:10.1016/j.appet.2007.09.015.PMC2274963.PMID17996982.nihmsid: NIHMS42868.
- ^Porter, Ryan F.; Gyawali, C. Prakash."Nausea and Vomiting".Patient Education & Resource Center.American College of Gastroenterology.