The term acute abdomen refers to the rapid onset of severe symptoms that may indicate potentially life-threatening intra-abdominal pathology that requires urgent surgical intervention.
Clinical features
Abdominal pain is usually a feature, but a pain-free acute abdomen can occur, particularly in older people, children, and the immunocompromised, and in the last trimester of pregnancy. Acute abdominal symptoms are common.[1]Flasar MH, Cross R, Goldberg E. Acute abdominal pain. Prim Care. 2006 Sep;33(3):659-84.
http://www.ncbi.nlm.nih.gov/pubmed/17088154?tool=bestpractice.com
[2]Silen W. Cope's early diagnosis of the acute abdomen. 18th ed. New York, NY: Oxford Press; 1991.[3]Jung PJ, Merrell RC. Acute abdomen. Gastroenterol Clin North Am. 1988 Jun;17(2):227-44.
http://www.ncbi.nlm.nih.gov/pubmed/3049343?tool=bestpractice.com
Estimates vary, but one study of upper abdominal pain identified a prevalence of around 50%,[4]Heading RC. Prevalence of upper gastrointestinal symptoms in the general population: a systematic review. Scand J Gastroenterol Suppl. 1999;231:3-8.
http://www.ncbi.nlm.nih.gov/pubmed/10565617?tool=bestpractice.com
while one large telephone survey found that 45% of people had experienced at least one upper gastrointestinal symptom in the previous 3 months.[5]Camilleri M, Dubois D, Coulie B, et al. Prevalence and socioeconomic impact of upper gastrointestinal disorders in the United States: results of the US Upper Gastrointestinal Study.Clin Gastroenterol Hepatol. 2005 Jun;3(6):543-52.
http://www.ncbi.nlm.nih.gov/pubmed/15952096?tool=bestpractice.com
Acute abdominal pain is a frequent presentation in the emergency department. Pain may:
Be located in any quadrant of the abdomen
Be intermittent, sharp or dull, achy, or piercing
Radiate from a focal site
Be accompanied by nausea and vomiting.
Immediate assessment should focus on distinguishing patients with true acute abdomen that requires urgent surgical intervention from patients who can initially be managed conservatively.[2]Silen W. Cope's early diagnosis of the acute abdomen. 18th ed. New York, NY: Oxford Press; 1991. Data from the UK suggest that access to an experienced surgeon reduces unnecessary admissions.[6]Association of Surgeons of Great Britain and Ireland. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication].
https://www.evidence.nhs.uk/document?id=2092186&returnUrl=search%3fq%3d%25e2%2580%258bCommissioning%2bguide%253a%2bemergency%2bgeneral%2bsurgery%25e2%2580%258b&q=%E2%80%8BCommissioning+guide%3a+emergency+general+surgery%E2%80%8B
A patient with acute surgical pathology may deteriorate rapidly; therefore, patients with severe, unremitting symptoms in the first few hours warrant vigorous investigation and close monitoring.
Diagnostic workup
An acute abdomen is diagnosed by a combination of history, physical examination, radiography, and laboratory results. When symptoms do not necessitate immediate surgery and when imaging has not led to a definitive diagnosis, further abdominal examination by an experienced physician may help to determine the underlying cause.[3]Jung PJ, Merrell RC. Acute abdomen. Gastroenterol Clin North Am. 1988 Jun;17(2):227-44.
http://www.ncbi.nlm.nih.gov/pubmed/3049343?tool=bestpractice.com
Alternatively, diagnostic laparoscopy can be considered in selected patients.[7]Stefanidis D, Richardson WS, Chang L, et al. The role of diagnostic laparoscopy for acute abdominal conditions: an evidence-based review. Surg Endosc. 2009 Jan;23(1):16-23.
http://www.ncbi.nlm.nih.gov/pubmed/18814014?tool=bestpractice.com
[8]Maggio AQ, Reece-Smith AM, Tang TY, et al. Early laparoscopy versus active observation in acute abdominal pain: systematic review and meta-analysis. Int J Surg. 2008 Oct;6(5):400-3.
http://www.journal-surgery.net/article/S1743-9191(08)00086-1/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/18760983?tool=bestpractice.com
[9]Society of American Gastrointestinal and Endoscopic Surgeons. Guidelines for diagnostic laparoscopy. April 2010 [internet publication].
https://www.sages.org/publications/guidelines/guidelines-for-diagnostic-laparoscopy/
Laparoscopy is not only a useful tool for diagnosis but is increasingly used as a therapeutic measure for appendicitis, cholecystitis, lysis of adhesions, hernia repair, and many gynecologic causes of an acute abdomen.
Diagnostic accuracy may be improved by using algorithms or decision tools, although further prospective studies are required to fully evaluate their clinical use. The Appendicitis Inflammatory Response (AIR) score and the novel Pediatric Appendicitis Risk Calculator (pARC) have been shown to help stratify risk of appendicitis in patients presenting with acute abdominal pain.[10]Scott AJ, Mason SE, Arunakirinathan M, et al. Risk stratification by the Appendicitis Inflammatory Response score to guide decision-making in patients with suspected appendicitis. Br J Surg. 2015 Apr;102(5):563-72.
http://www.ncbi.nlm.nih.gov/pubmed/25727811?tool=bestpractice.com
[11]Kharbanda AB, Vazquez-Benitez G, Ballard DW, et al. Development and validation of a novel Pediatric Appendicitis Risk Calculator (pARC). Pediatrics. 2018 Apr;141(4).
https://pediatrics.aappublications.org/content/141/4/e20172699.long
http://www.ncbi.nlm.nih.gov/pubmed/29535251?tool=bestpractice.com
Narcotic analgesia
Use of narcotic analgesia in undiagnosed patients with an acute abdomen has traditionally been discouraged.[12]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660.
http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD005660.pub3/full
http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
[13]Helfand M, Freeman M. Assessment and management of acute pain in adult medical inpatients: a systematic review. Pain Med. 2009 Oct;10(7):1183-99.
http://onlinelibrary.wiley.com/doi/10.1111/j.1526-4637.2009.00718.x/full
http://www.ncbi.nlm.nih.gov/pubmed/19818030?tool=bestpractice.com
This is because of concerns that symptoms would be masked, the examination hindered, and, therefore, the correct diagnosis missed. Recent reviews, however, suggest that narcotic analgesia does not hinder management and improves patient comfort.[12]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660.
http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD005660.pub3/full
http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
[
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In people with acute abdominal pain with an undiagnosed cause, how does the use of opioid analgesia affect the clinical evaluation process?/cca.html?targetUrl=http://cochraneclinicalanswers.com/doi/10.1002/cca.536/fullShow me the answer Fentanyl or one of its analogs can be a useful agent in this situation due to the combination of potency and short half-life.
Special groups
Abdominal pain in older people, the immunocompromised, and pregnant women often presents atypically. Combined with a lack of understanding of the physiologic changes in these patients’ response to certain diseases, this means their diagnosis and treatment is often delayed, and complication and mortality rates are consequently higher.[14]Chen EH, Mills AM. Abdominal pain in special populations. Emerg Med Clin North Am. 2011 May;29(2):449-58.
http://www.ncbi.nlm.nih.gov/pubmed/21515187?tool=bestpractice.com
Older people
Older people usually have more long-standing comorbidities than younger adults, which can further affect their ability to mount characteristic physiologic responses (this may be due to direct effects of a comorbid condition or to medications used to treat the comorbid condition). Older patients are also at higher risk for more severe disease due to decreased immune function.[15]Ragsdale L, Southerland L. Acute abdominal pain in the older adult. Emerg Med Clin North Am. 2011 May;29(2):429-48.
http://www.ncbi.nlm.nih.gov/pubmed/21515186?tool=bestpractice.com
Central and peripheral nervous systems are affected by aging. Conditions such as dementia can restrict an older person's ability to communicate problems, and decreased peripheral nervous system function can alter perception of pain and temperature, making diagnosis and management more difficult. One study of patients with perforated ulcers found that only 21% of older patients presented with peritonitis.[15]Ragsdale L, Southerland L. Acute abdominal pain in the older adult. Emerg Med Clin North Am. 2011 May;29(2):429-48.
http://www.ncbi.nlm.nih.gov/pubmed/21515186?tool=bestpractice.com
Pregnant women
The physical and physiologic changes associated with pregnancy may present a challenge to diagnosis and treatment. A prompt and thorough evaluation is essential as a delay in diagnosis and treatment can lead to poor outcomes for both mother and fetus.[16]Kilpatrick CC, Monga M. Approach to the acute abdomen in pregnancy. Obstet Gynecol Clin North Am. 2007 Sep;34(3):389-402.
http://www.ncbi.nlm.nih.gov/pubmed/17921006?tool=bestpractice.com
The enlargement of the uterus, which displaces and compresses intra-abdominal organs, and the laxity of the abdominal wall makes it difficult to localize pain and can blunt peritoneal signs.[16]Kilpatrick CC, Monga M. Approach to the acute abdomen in pregnancy. Obstet Gynecol Clin North Am. 2007 Sep;34(3):389-402.
http://www.ncbi.nlm.nih.gov/pubmed/17921006?tool=bestpractice.com
Pregnant women may sometimes have a mild physiologic leukocytosis, so this finding is nonspecific in pregnant women presenting with an acute abdomen. If there is a high index of suspicion for intra-abdominal pathology, further studies are warranted and may include additional laboratory testing, radiographic testing, or in some cases serial physical examinations.
There is concern among healthcare providers and patients around the issue of obtaining radiographs on pregnant patients. Although it is known that ionizing radiation exposure can lead to cell death, mutation of germ cells, and carcinogenesis, there is no common modern radiographic procedure that results in radiation exposure to a level that threatens embryo or fetal well-being.[16]Kilpatrick CC, Monga M. Approach to the acute abdomen in pregnancy. Obstet Gynecol Clin North Am. 2007 Sep;34(3):389-402.
http://www.ncbi.nlm.nih.gov/pubmed/17921006?tool=bestpractice.com
Radiation exposure of <5 rads (a computed tomographic abdomen/pelvis study carries an exposure of 3.5 rads) has not been associated with fetal defects or loss.[16]Kilpatrick CC, Monga M. Approach to the acute abdomen in pregnancy. Obstet Gynecol Clin North Am. 2007 Sep;34(3):389-402.
http://www.ncbi.nlm.nih.gov/pubmed/17921006?tool=bestpractice.com
Careful shielding of the patient can also minimize exposure. Importantly, the use of ultrasound for diagnosis is clearly safe in pregnancy, although it should be used to evaluate and answer a defined clinical problem.[17]American College of Radiology. ACR–ACOG–AIUM–SRU practice parameter for the performance of obstetrical ultrasound. 2018 [internet publication].
http://www.acr.org/~/media/ACR/Documents/PGTS/guidelines/US_Obstetrical.pdf
It is important to discuss the risks and benefits with patients before obtaining radiographs. Any risk must be carefully balanced against the increased risk of fetal and maternal death resulting from a delay in diagnosis and treatment. Alternatives to ionizing radiation imaging, such as ultrasound and magnetic resonance imaging, may also have important roles in these patients.