Continuing Education Activity
Postoperative ileus is a prolonged absence of bowel function after surgical procedures, usually abdominal surgery. It is a common postoperative complication with unclear etiology and pathophysiology. It is a benign condition that usually resolves with minimal intervention. Management of postoperative ileus relies on supportive care after excluding more serious and reversible surgical conditions such as mechanical obstruction. This activity reviews the evaluation and treatment of postoperative ileus and highlights the role of the interprofessional team in the care of patients with this condition.
Objectives:
Identify the etiology of postoperative ileus.
Review the appropriate evaluation process of postoperative ileus.
Outline the management options available for postoperative ileus.
Summarize interprofessional team strategies for improving care coordination and communication to advance the care of postoperative ileus and improve outcomes.
Introduction
Postoperative ileus is an abnormal pattern of slow or absent gastrointestinal motility in response to surgical procedures. Clinically, it is manifestedby intolerance of oral intake and abdominal distention due to inhibition of the gastrointestinal propulsion without signs of mechanical obstruction.[1][2][3]Generally,patients undergoing an abdominal surgical procedure will develop some degree of transient impairment of gastrointestinal motility. Often, thisis an uncomplicated sequela with little consequence. Some surgeons consider it as a normal physiologic response of the intestine to surgery.[4]
Prolonged impairment, however, can lead to several considerableimpediments, including increased hospital stay, healthcare costs, and patient discomfort. It is estimated that the economic impact of postoperative ileus isapproximately 750 million dollars annually in the United States alone.[5]The significance of postoperative ileus is that it simulates other serious complications like bowel obstruction, and it delays recovery. Therefore, optimizing measures to prevent and/or treat it appropriately after excluding other complications is imperativeto consider.
Etiology
Ileus is a commonconsequence of intra-abdominal surgical procedures. There is little consensus on when the gastrointestinal tract resumes motility postoperatively. However, colonic motility, which is the last to return, is typically restored within 72hrs. Thus, postoperative ileus lasting longer than this duration is often considered pathologic. While operative manipulation is traditionally blamed for inciting ileus, the exactmechanismswhich lead to a prolonged ileus are poorly understood. Therefore, it is difficult to predictwho will develop prolonged postoperative ileus. However, theseunderlyingmechanisms can be broken into three broad categories: neurogenic, inflammatory, and pharmacologic.[6]
Causes of postoperative ileus were studied extensively in efforts to prevent or treat the condition adequately. Multiple factors contribute to the development of the condition, but no direct causation relationship was confirmed with any of the factors. High correlation with ileus was identified with the following conditions:
Interruption of the GI continuity (in cases of resection) or manipulation of the bowel
Anesthetic and analgesic medications
Immobility
Electrolytes imbalance especially hypokalemia
Intra-abdominal hematoma
Intra-abdominal severe infection or sepsis
Chronic medical conditions like diabetes mellitus (DM)
Local or generalized abdominal inflammation like pancreatitis
Severe pain
Cardiopulmonary failure
Epidemiology
Some degree of postoperative ileus is nearly universal after abdominal surgery. Up to25% of patients will develop postoperative ileus after elective abdominal surgery.[7]Prolonged ileus, while less common, is still frequently seen afterintra-abdominal operations. The prevalence of prolonged postoperative ileus after colorectal surgery is anywhere from 5% to 30%.[8]Theoretically,increased intestinal manipulation or large incisions are associated with a higher risk of postoperative ileus than laparoscopic approaches or abdominal surgeries with minimal intestinal manipulation, such as cholecystectomy.[9][10][11]
Pathophysiology
The exact mechanism and causes of postoperative ileus are incompletely understood. However,the pathophysiology of postoperative ileus can be attributed to the following three categories of mechanisms: neurogenic, inflammatory, and pharmacologic. The autonomic nervous system plays a majorrole in gastrointestinal motility. The parasympathetic system stimulates motility while the sympathetic system inhibits motility. Increased sympathetic stimulation plays a role in the inhibition of gastrointestinal motility after surgery. Hormones and neurotransmitters, such as nitric oxide, calcitonin-gene-related peptide, and corticotropin-releasing factor, may induce the development of postoperative ileus. Postoperative ileus is more likely to develop after prolonged major surgical procedures and general anesthesia with excessive gastrointestinal manipulation or interruption.Postoperative pain medication, particularly opioids, promotesthe development or worsening of postoperative ileus due to their known inhibitory effect on gut motility.[6]
History and Physical
Delayed bowel movement or passage of flatus is the hallmark of postoperative ileus. Common symptoms include abdominal distension, bloating, diffuse, persistent pain, nausea, vomiting, inability to passflatus, and intolerance toan oral diet. Physical exam findings are also typically non-specific, but often patients can have distended, tympanic abdomens on exam associated with absent or sluggish bowel sounds. Tenderness or rebound tenderness should be further investigated for other more serious causes.
Evaluation
The diagnosis of postoperative ileus is clinical. Postoperative ileus causes delayed bowel movement or flatus with abdominal distention and possible nausea or vomiting. It is crucial to differentiate ileus from other causes of the above clinical picture, especially mechanical bowel obstruction. There are some differences that can assist clinicians in distinguishing between the two entities. Postoperative ileus is more insidious in nature.In mechanical obstruction, symptoms are usually more acute and severe. Radiologically (X-rays and computed tomography scans), ileus shows diffuse air-fluid levels and bowel distention, while mechanical bowel obstruction demonstrates a transition point with dilated proximal and collapsed distal small bowel.
The evaluation of ileus focuses on looking for other treatable similar conditions and identifying the predisposing factors. Some factors, like peritonitis or intra-abdominal bleeding, necessitateurgent active treatment of the primary causes. In addition to the clinical assessment, biochemical profile assessment, medications review, pain and analgesics review, patient's ambulation assessment, and co-existing constipation should be considered.
Treatment / Management
Management of postoperative ileus revolves around supportive care. After excluding serious or treatable conditions, supportive treatment and optimizing care almost always resolve the ileus.These measuresinclude intravenous fluid replacement, electrolyte replacement, early ambulation, and often nasogastric tube placement. Some of these interventionsare aimed at reducing symptoms, such as nasogastric suction, but have little evidence supporting their overall usefulness otherwise.[12]
A careful balance between postoperative pain control and analgesics, especially opiates use, is crucial to prevent or treat the ileus. Non-opiate analgesics are encouraged. Optimizing electrolytes and other metabolites are important. Encouraging ambulation very early in the postoperative period is a simple but very important prevention and treatment measure. Regular and serial clinical assessments should be exerted with open eyes and mind for worsening complications or a missed diagnosis. Multiple studies have assessed a few treatment measures to overcome ileus but with no clinically significant outcomes. Studies on gum-chewing showed some improvement in the ileus. Therefore, this is occasionally but not widely used in clinical practice.
Differential Diagnosis
Postoperative ileus carries a nonspecific presentation. While not a surgical or medical emergency, many other diagnoses that share symptoms with postoperative ileus can be emergent. Distinguishing between ileus and mechanical obstruction both at onset and throughout the clinical course, is key. Further, several other intra-abdominal issues can yield similar symptoms to ileus and should be ruled out. This includes ischemia, abscess, surgical complication, or inflammation of the intra-abdominal organs, such as cholecystitis or pancreatitis.
Prognosis
Prognosis is generally good as postoperative ileus typically resolves within one to three days after diagnosis with supportive care. Should ileus remain for several days or symptoms continue to worsen despite management, further investigation and imaging is warranted.
Complications
Complications of postoperative ileus include prolonged hospital stay and increased healthcare costs. Postoperative ileus typically resolveswithin a few days, although continued ileus introduces complications associated with lack of enteral intake, electrolyte derangements, malnutrition, and poor patient satisfaction.
Deterrence and Patient Education
There is little evidence on risks associated with the development of postoperative ileus, although the invasiveness of surgery and the type of pain medication used play some role. Electing for laparoscopic procedures when possible and avoidance of opioid medications when possible are proven ways to lessen the chance of ileus.[12]
Pearls and Other Issues
Postoperative ileus is a common benign postoperative complication.
Normal physiologic recovery should occur within 72 hours with supportive treatment.
It is imperative to distinguish ileus from more severe or reversible problems such as mechanical obstruction.
Management is mainly supportive treatment, optimizing care, correcting predisposing factors, and clinical follow up.
Enhancing Healthcare Team Outcomes
Postoperative ileus is a surgical complication that requires a unified,interprofessional team approach to manage appropriately. Clinicians, nurses, dietitians, pharmacists, pain management team, and physiotherapists should remain in constant communication to identify the condition early and apply the management measures cordially.
Supportive management, when possible, includes electrolyte replacement, intravenous fluids, ambulation, pain control, and analgesics adjustment, as well as correcting the underlying causes. Therapists play an important role in early ambulation (regarding physical and occupational therapy) and progression of diet (regarding speech therapy). Pharmacists are also of utmost importance in medication review, limiting opioid exposure if possible, and assisting in providing alternative pain regimens.
References
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Vather R, Trivedi S, Bissett I. Defining postoperative ileus: results of a systematic review and global survey. J Gastrointest Surg. 2013 May;17(5):962-72. [PubMed: 23377782]
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Vather R, O'Grady G, Bissett IP, Dinning PG. Postoperative ileus: mechanisms and future directions for research. Clin Exp Pharmacol Physiol. 2014 May;41(5):358-70. [PubMed: 24754527]
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Stakenborg N, Gomez-Pinilla PJ, Boeckxstaens GE. Postoperative Ileus: Pathophysiology, Current Therapeutic Approaches. Handb Exp Pharmacol. 2017;239:39-57. [PubMed: 27999957]
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Senagore AJ. Pathogenesis and clinical and economic consequences of postoperative ileus. Am J Health Syst Pharm. 2007 Oct 15;64(20 Suppl 13):S3-7. [PubMed: 17909274]
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Luckey A, Livingston E, Taché Y. Mechanisms and treatment of postoperative ileus. Arch Surg. 2003 Feb;138(2):206-14. [PubMed: 12578422]
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Su'a BU, Pollock TT, Lemanu DP, MacCormick AD, Connolly AB, Hill AG. Chewing gum and postoperative ileus in adults: a systematic literature review and meta-analysis. Int J Surg. 2015 Feb;14:49-55. [PubMed: 25576763]
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Flores-Funes D, Campillo-Soto Á, Pellicer-Franco E, Aguayo-Albasini JL. The use of coffee, chewing-gum and gastrograffin in the management of postoperative ileus: A review of current evidence. Cir Esp. 2016 Nov;94(9):495-501. [PubMed: 27456544]
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Iyer S, Saunders WB, Stemkowski S. Economic burden of postoperative ileus associated with colectomy in the United States. J Manag Care Pharm. 2009 Jul-Aug;15(6):485-94. [PMC free article: PMC10438346] [PubMed: 19610681]
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Moghadamyeghaneh Z, Hwang GS, Hanna MH, Phelan M, Carmichael JC, Mills S, Pigazzi A, Stamos MJ. Risk factors for prolonged ileus following colon surgery. Surg Endosc. 2016 Feb;30(2):603-609. [PubMed: 26017914]
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Twine CP, Humphreys AK, Williams IM. Systematic review and meta-analysis of the retroperitoneal versus the transperitoneal approach to the abdominal aorta. Eur J Vasc Endovasc Surg. 2013 Jul;46(1):36-47. [PubMed: 23590870]
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Kehlet H, Holte K. Review of postoperative ileus. Am J Surg. 2001 Nov;182(5A Suppl):3S-10S. [PubMed: 11755891]
Disclosure: Lucas Buchanan declares no relevant financial relationships with ineligible companies.
Disclosure: Faiz Tuma declares no relevant financial relationships with ineligible companies.
