Perspectives on the importance of postoperative ileus

Abstract

Post-operative ileus (POI) is a common condition after surgery. Failure to restore adequate bowel function after surgery generates a series of complications and it is associated to patients frustration and discomfort, worsening their perioperative experience. Even mild POI can be source of anxiety and could be perceived as a drop out from the “straight-forward” pathway. Enhanced recovery programmes have emphasized the importance of early commencement of oral diet, avoiding the ancient dogmata of prolonged gastric decompression and fasting. These protocols with early oral feeding and mobilization have led to improved perioperative management and have decreased hospital length of stay, ameliorating patient's postoperative experience as well. Nonetheless, the incidence of POI is still high especially after major open abdominal surgery. In order to decrease the incidence of POI, minimally-invasive surgical approaches and minimization of surgical manipulation have been suggested. From a pharmacological perspective, a meta-analysis of pro-kinetics showed beneficial results with alvimopan, although its use has been limited by the augmented risk of myocardial infarction and the high costs. A more simple approach based on the postoperative use of chewing-gum has provided some benefits in restoring bowel function. From an anaesthesiological perspective, epidural anaesthesia/analgesia does not only reduce the postoperative consumption of systemic opioids but directly improve gastrointestinal function and should be considered where possible, at least for open surgical procedures. POI represents a common and debilitating complication that should be challenged with multi-disciplinary approach. Prospective research is warranted on this field and should focus also on patient s reported outcomes.

Keywords: :

• Alvimopan
• Chewing gum
• Epidural anesthesia
• Laparoscopic surgery
• Open lower abdominal surgery
• Postoperative ileus

In this issue of Current Medical Research and Opinion, Gan et al.1 publish the results of a large retrospective analysis of the Premier database showing a cumulative 10% overall incidence of postoperative ileus (POI) in patients undergoing colectomy or cholecystectomy (open or laparoscopic). Notably, POI was not only associated with the amount of opioids administered, but also with significantly prolonged hospital stay, costs, and 30 day readmission rate.

Failure to restore adequate bowel function generates not only a series of complications (immobility, nausea and vomiting, and increased catabolism to name a few) but also frustration and discomfort for patients, worsening the perioperative experience. Even mild POI can be a source of anxiety for patients and is perceived as a drop out from the expected straightforward pathway.

Traditionally, the impact of POI is considered to be different across the gastrointestinal tract: the small intestine recovers its function more quickly (0–24 h) than the stomach (24–48 h) and colon (48–72 h)2. However, this belief has been questioned and gastric and ileal motility has been shown to return even within a few hours after surgery3. Yet, enhanced recovery protocols have substituted the ancient dogmata of prolonged gastric decompression and delayed commencement of oral diet, and have improved the perioperative management of surgical patients by implementing early oral feeding and early mobilization. This has decreased the hospital length of stay and improved patients’ experience4^,5.

Different strategies have been pursued in order to decrease POI and its complications, and to ameliorate the postoperative patient’s experience. Certainly, incidence of POI depends upon the type and technique of surgery and open lower abdominal surgery (e.g., colorectal) is well known to be associated with higher rates. Minimizing surgical manipulation of the bowel6 and implementing minimally invasive surgical approaches are among the most commonly adopted options for improving recovery during the postoperative period and reducing the course of POI7.

From a pharmacological perspective, a meta-analysis of different pro-kinetic agents showed beneficial results with alvimopan, an antagonist of peripheral mu-opioid receptors8. However, high costs and concern about an increased risk of myocardial infarction have limited the use of alvimopan9. Also the postoperative use of chewing-gum has shown a beneficial effect for the recovery of gastrointestinal motility, as reported in a systematic review of five clinical trials10.

Gan et al. elegantly selected four groups of patients, according not only to the anatomical site of surgery (upper vs lower gastrointestinal surgery), but also to the technical approach (open vs laparoscopic). The highest incidence of POI was found in patients undergoing colectomy, with similar figures to those reported in a previous analysis of the Premier database11. The lower incidence of POI in the population undergoing laparoscopic procedures compared with the corresponding open procedure ones is not surprising. Yet laparoscopic surgery is associated with reduced surgical trauma and a more blunted inflammatory response12, and therefore with an earlier recovery of gastrointestinal motility and lower postoperative pain and opioid consumption13. As expected, Gan et al. report lower opioid requirements and weaker association with POI in the laparoscopic groups compared to patients undergoing open procedures. Although the association between POI and opioid administration is confirmed by the authors, it is of course important to consider that this is a retrospective analysis. Therefore, the interpretation of these results warrants cautiousness since it represents a two-fold phenomenon: POI increases pain and discomfort requiring analgesic treatment, and on the other hand opioids are often used in such cases despite the fact that they are well known to slow gastrointestinal motility, thus creating a vicious cycle.

From an anesthesiological perspective, any opioid-sparing strategies such as the use of an epidural catheter for analgesia should be considered, at least for open surgical procedures, in order to reduce postoperative complications. Moreover, epidural anesthesia not only decreases the consumption of systemic opioids in the postoperative period but is also directly responsible for improving gastrointestinal function14.

In summary, all the measures associated with a reduction in the incidence of POI should be strongly considered by all healthcare operators because of the established association of POI with hospital length of stay and costs, readmission rates and patient experience. Further prospective research is warranted and should also include patient reported outcomes15.

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Declaration of funding

None.

Declaration of financial/other relationships

F.S. and G.S. have disclosed that they have no significant relationships with or financial interests in any commercial companies related to this study or article.