New therapies in the treatment of postoperative ileus after gastrointestinal surgery

Effect of Yikou-Sizi powder hot compress on gastrointestinal functional recovery in patients after abdominal surgery: Study protocol for a randomized controlled trial

BACKGROUND

Postoperative gastrointestinal dysfunction (PGD) is a common complication of patients who have undergone surgery. The clinical manifestations cause great discomfort to postoperative patients and can severely affect postoperative recovery. However, although various pharmacologic agents have been explored for several years, success has been limited. Because some commonly used drugs have caused adverse reactions and because abdominal surgery patients generally cannot consume food or medication during the perioperative period, we were prompted to try an external Chinese medicine treatment method. Yikou-Sizi powder hot compress is an efficient therapy in our hospital, but there is a lack of rigorous studies to certify the safety and effectiveness of its external use to improve gastrointestinal motility. This study aimed to introduce the clinical trial design and test the ability of Yikou-Sizi powder hot compress treatment to accelerate gastrointestinal functional recovery after abdominal surgery.

METHODS

This study is a randomized controlled clinical trial. The participants will undergo laparoscopic colorectal cancer surgery and laparoscopic total hysterectomy. The primary outcome measure will be the gastrointestinal functional evaluation index, including the time to first passage of flatus, first defecation, first normal bowel sounds, and first consumption of liquid/semigeneral diet foods. According to good clinical practice (GCP), we will evaluate the clinical efficacy and safety of Yikou-Sizi powder hot compress and objectively study the acting mechanism of ghrelin. This pilot trial will be a standard, scientific, and clinical study designed to evaluate the effect of Yikou-Sizi powder hot compress for the recovery of gastrointestinal function after surgery and determine its overall safety.

DISCUSSION

This is the first study to describe the use of Yikou-Sizi powder hot compress to accelerate the recovery of gastrointestinal function after abdominal surgery. The study is designed as a randomized, controlled, clinical, large sample size and pilot trial. Evaluation will consist of combining the primary outcome measures with secondary outcome measures to ensure the objectivity and scientific validity of the study. Due to the observational design and the limited follow-up period, it is not possible to evaluate to what extent the connection between the observed improvement and the interventions represents a causal relationship. Efficient comparison between groups will be analyzed by chi-square test.

Stereoselective HPLC separation of alvimopan on cellulose-based immobilized polysaccharide as a chiral stationary phase

Chiral separation by normal phase high performance liquid chromatography is one of the most powerful technique to quantify the chiral purity of the compounds. In this study, a novel, simple, and specific analytical method was proposed to ascertain the chiral purity of alvimopan (ALV). The normal phase HPLC method was developed based on cellulose tris (3,5-dichlorophenylcarbamate) stationary phase. The separation of ALV isomers achieved by using column CHIRALPAK IC (250 × 4.6 mm, 5 μm), mobile phase n-hexane: isopropyl alcohol: ethanol: diethylamine (650:200:150:5 v/v), column oven temperature 30°C, flow rate 1.0 mL min-1 , injection volume was 10 μL, chromatographic response monitored at 273 nm. The developed method was validated as per the ICH guidelines and found precise, accurate, and linear. The advantage of the method is a good separation of ALV isomers within 35 minutes of the analysis time. Therefore, this method is suitable for routine determination of chiral purity of ALV active pharmaceutical ingredient.

Mapping the Road to Recovery: Shorter Stays and Satisfied Patients in Posterior Spinal Fusion

BACKGROUND

Adolescent idiopathic scoliosis (AIS) patients undergoing posterior spinal fusion (PSF) experience variations in their hospital care, which may lead to differences in objective and patient-reported outcomes. The purpose of this study was to demonstrate that using plan of care-educating families preoperatively and standardizing some aspects of care-would decrease time to mobility and time to discharge while maintaining pain control and patient satisfaction.

METHODS

Chart review was conducted in 3 groups-preprotocol (December 2008 to December 2009, n=51), first protocol (December 2, 2009 to July 24, 2013, n=100), and second protocol (July 25, 2013 to June 1, 2014, n=39)-to track pain scores (0 to 10), time to regular diet, Foley catheter removal, epidural catheter removal, mobility, and discharge. Patient satisfaction surveys (0 to 10) were administered before discharge. Statistical analysis was performed using a 1-way analysis of variance test with Tukey post hoc analysis.

RESULTS

Average pain scores were similar in all groups. Time to sitting was significantly reduced in both first protocol (27.2±9.8 h, P=1×10) and second protocol (28.4±13.6 h, P=3×10) compared with preprotocol (40.2±15.4 h). Time to discharge was significantly lower in second protocol (84.3±27.2 h, P=0.036) compared with first protocol (98.4±27.8 h). Patient satisfaction with care was significantly higher in first protocol (9.1/10, P=2×10) and second protocol (8.6/10, P=5×10) compared with preprotocol (6.5/10).

CONCLUSIONS

By educating families preoperatively and standardizing portions of postoperative care in PSF for AIS, pain scores were significantly reduced while overall satisfaction remained high. Specifically, by removing the epidural and Foley catheters on postoperative day 2, time to discharge was dramatically decreased by 15 hours. The application of a multidisciplinary, evidence-driven plan of care for AIS patients undergoing PSF improves throughput and has beneficial effects on objective and patient-reported outcomes.

LEVEL OF EVIDENCE

Level III-retrospective case series.

Metoclopramide role in preventing ileus after cesarean, a clinical trial

PURPOSE

Ileus is a common event following cesarean section. Early post-cesarean recovery is very important not only for the mother but also for the baby who is dependent on breastfeeding. This article aims to demonstrate the efficacy of metoclopramide for the prevention of ileus after cesarean.

METHODS

In this randomized controlled trial, 696 women scheduled for cesarean were randomized in two groups. Three hundred fifty-three persons settled in control group and 343 were assigned in intervention group who received an injection of 10-mg intramuscular metoclopramide prior to operation. After cesarean, the participants recorded the first flatus, defecation, feeling of hunger, feeding and ambulation in a questionnaire, and also their sense of bloating in a visual analog scale under supervision of a research assistant. The data was analyzed by SPSS 17, t test, and chi-square, while p < 0.05 was considered significant.

RESULTS

The interval between cesarean and the first flatus (p < 0.0001), defecation (p < 0.0001), feeling of hunger (p < 0.0001), feeding (p = 0.007), and ambulation (p < 0.0001) were significantly shorter in the metoclopramide group. In addition, polytomous logistic regression analysis showed the metoclopramide group had less bloating with significant difference (OR = 2.83 and CI 1.91-4.21).

CONCLUSIONS

Our study proved the functionality of metoclopramide in preventing ileus. As this drug is safe, tolerable, harmless, inexpensive and available, and also no definite method has been developed to prevent ileus after cesarean; yet, metoclopramide could be considered as a suitable option. Certainly with regard to some limitations in our study, further comprehensive studies are still required to ensure validity of the obtained results.

Effect of prolonged general anesthesia with sevoflurane and laparoscopic surgery on gastric and small bowel propulsive motility and pH in dogs

OBJECTIVE

To determine if general anesthesia with sevoflurane and laparoscopic surgery changed gastric and small bowel propulsive motility or pH in dogs.

STUDY DESIGN

Prospective, controlled trial.

ANIMALS

Twelve, 19-24 months old, female, Treeing Walker Hound dogs, weighing 23-30 kg.

METHODS

Dogs were anesthetized for a median of 8.5 hours during another study to determine the minimum alveolar concentration of sevoflurane using a visceral stimulus. Gastric and small bowel motility were determined using a sensor capsule that measures pressure, pH and temperature. Gastric transit time and motility index were calculated. For 8/12 dogs, gastric motility, pH and transit time were measured. In 4/12 dogs, small bowel motility and pH were measured.

RESULTS

Anesthesia decreased gastric and small bowel motility but did not change luminal pH. Mean gastric contraction force decreased from median (range) 11 (8-20) to 3 (1-10) mmHg (p < 0.01) and gastric motility index decreased from 0.63 (0-1.58) to 0 (0-0.31; p = 0.01). Frequency of contractions did not change, 3.7 (1.6-4.4) versus 2.8 (0.1-5.1) contractions minute(-1) (p = 0.1). Gastric motility returned to normal 12-15 hours following anesthesia. Gastric emptying was prolonged from 12 (5.3-16) to 49 (9.75-56.25) hours (p < 0.01). Mean small bowel contraction force decreased from 34 (24-37) to 3 (0.9-17) mmHg (p < 0.02) and motility index decreased from 3.75 (1-4.56) to 0 (0-1.53; p = 0.02). Frequency of contractions did not change, 0.5 (0.3-1.4) versus 1.4 (0.3-4.6) contractions minute(-1) (p = 0.11). Small bowel motility returned within 2 hours after anesthesia. Laparoscopy did not result in changes to gastric or small bowel parameters beyond those produced by general anesthesia.

CONCLUSIONS AND CLINICAL RELEVANCE

The force of gastric and small bowel contractions decreased during sevoflurane anesthesia for laparoscopy. Although gastric motility returned to normal within 12-15 hours the impairment of gastric emptying lasted 30-40 hours, predisposing dogs to postoperative ileus.

Chewing gum reduces postoperative ileus following abdominal surgery: a meta-analysis of 17 randomized controlled trials

BACKGROUND AND AIM

Chewing gum proposal has been used in surgery to reduce postoperative ileus for more than 10 years; however, the efficacy remains imprecise. The aim of this study was to accurately assess whether the use of the chewing gum could reduce duration of postoperative ileus following the abdominal surgery.

METHODS

A systematic review was conducted in Medline, EMBASE, and the Cochrane Library through December 2012 to identify randomized controlled trials comparing with and without the use of chewing gum in patients undergoing abdominal surgery. The outcome of interest was time to flatus, time to bowel movement, and length of stay. Subgroup analyses were performed to examine the impact of different studies structural design. Cumulative meta-analyses were used to examine how the evidence has changed over time.

RESULTS

Seventeen randomized controlled trials involving 1374 participants were included. Overall time (in days) for the patients to pass flatus (weighted mean difference [WMD], -0.31; 95% confidence interval [CI], -0.43 to -0.19; P = 0.000); time to bowel movement (WMD, -0.51; 95% CI, -0.73 to -0.29; P = 0.000); and length of stay (WMD, -0.72; 95% CI, -1.02 to -0.43; P = 0.000) were significantly reduced in the treatment group. However, both of these results demonstrated significant heterogeneity. No evidence of publication bias was observed. Cumulative meta-analysis showed that chewing gum reduces duration of postoperative ileus that has been available for over 6 years.

CONCLUSIONS

Results of the meta-analysis suggest that chewing gum following abdominal surgery offers benefits in reducing the time of postoperative ileus.

The effect of erythromycin on gastrointestinal motility in subtotal gastrectomized patients

Purpose

Our objective was to determine the effect of erythromycin (EM) in improving gastrointestinal motility in subtotal gastrectomized patients. We used radio-opaque Kolomarks as an objective method. We conducted a prospective, controlled clinical trial study of 24 patients.

Methods

All patients underwent subtotal gastrectomy with 3 capsules containing Kolomarks (20 markers per 1 capsule) in the remnant stomach before anastomosis. From the day of the operation to the 2nd postoperative day, patients in the EM group began receiving 200 mg of EM intravenously for 30 minutes continuously. We counted the number of Kolomarks in the stomach, passed by stomach, in rectum, and in stool with serial simple abdominal X-ray films on the first postoperative day up to the 7th postoperative day.

Results

The study population included 14 patients in the control group and 10 patients in the EM group. The two study groups were compared in terms of their characteristics including age, gender, past medical history, cancer stage, and operation type. No significant differences were found for the demographics between the two groups. We only found a significant difference for the number of Kolomarks passed by the stomach on the 3rd postoperative day (P = 0.026).

Conclusion

Our results demonstrated that 200 mg of EM intravenous infusion during the postoperative period induced rapid gastric emptying, although it did not improve gastrointestinal motility for the entire gastrointestinal tract in subtotal gastrectomized patients.

Chewing reduces sympathetic nervous response to stress and prevents poststress arrhythmias in rats

Reducing stress is important in preventing sudden death in patients with cardiovascular disease, as stressful events may cause autonomic imbalance and trigger fatal arrhythmias. Since chewing has been shown to inhibit stress-induced neuronal responses in the hypothalamus, we hypothesized that chewing could ameliorate stress-induced autonomic imbalance and prevent arrhythmias. To test this hypothesis, we analyzed changes in radiotelemetered electrocardiograms in rats that were allowed to chew a wooden stick during a 1-h period of immobilization stress. Chewing significantly reduced the occurrence of ventricular premature beats (VPBs) and complex ventricular ectopy after immobilization and prevented stress-induced prolongation of the QT interval of VPBs throughout the 10-h experimental period. It also prevented prolongation of the QRS complex and fluctuations in the QT interval in normal sinus rhythm beats preceding VPBs during both immobilization and in the poststress period. Fast Fourier transform-based spectral analysis of heart-rate variability further showed that chewing significantly inhibited the stress-induced increase in the power ratio of low-to-high frequency activity (LF/HF: a marker of sympathetic activity) during immobilization and in addition was associated with blunting of the stress-induced increase in plasma noradrenaline observed at the termination of immobilization. Similar suppressive effects on the occurrence of VPBs and the LF/HF were observed in rats that were administered the β-adrenergic blocker propranolol before immobilization. These results indicate that chewing can ameliorate sympathetic hyperactivity during stress and prevent poststress arrhythmias and suggest that chewing may provide a nonpharmacological and cost-effective treatment option for patients with a high risk of stress-induced fatal arrhythmia.

Acute intestinal failure

PURPOSE OF REVIEW

The review aims to highlight the importance of acute gastrointestinal failure in the postoperative patient, to clarify the clinical circumstances in which acute intestinal failure complicates postoperative management, and to discuss recent advances and controversy in our understanding of the cause and pathogenesis.

RECENT FINDINGS

Acute postoperative intestinal failure ranges from a self-limiting condition of disordered intestinal peristaltic activity, through to a complex critical illness state associated with abdominal sepsis and intestinal fistulation. Recent developments have focused on the mechanisms of paralytic ileus and preventive strategies, usually as part of programmes of 'fast-track' or 'enhanced recovery' care, and on the optimum management of patients with severe abdominal sepsis, including planned versus on-demand relaparotomy, open abdominal management of severe sepsis and negative pressure wound therapy.

SUMMARY

Many cases of acute intestinal failure are preventable. Improvements in understanding and preventing paralytic ileus through changes in postoperative care may facilitate recovery of gastrointestinal function after abdominal surgery. Further and better-organized studies are needed to define the optimum strategies for treating patients with severe abdominal sepsis, managing the patient with the open abdomen and defining the role of enteral, as opposed to parenteral nutritional support in such patients.

Peritoneal damage: the inflammatory response and clinical implications of the neuro-immuno-humoral axis

BACKGROUND

The peritoneum is a bilayer serous membrane that lines the abdominal cavity. We present a review of peritoneal structure and physiology, with a focus on the peritoneal inflammatory response to surgical injury and its clinical implications.

METHODS

We conducted a nonsystematic clinical review. A search of the Ovid MEDLINE database from 1950 through January 2009 was performed using the following search terms: peritoneum, adhesions, cytokine, inflammation, and surgery.

RESULTS

The peritoneum is a metabolically active organ, responding to insult through a complex array of immunologic and inflammatory cascades. This response increases with the duration and extent of injury and is central to the concept of surgical stress, manifesting via a combination of systemic effects, and local neural pathways via the neuro-immuno-humoral axis. There may be a decreased systemic inflammatory response after minimally invasive surgery; however, it is unclear whether this is due to a reduced local peritoneal reaction.

CONCLUSIONS

Interventions that dampen the peritoneal response and/or block the neuro-immuno-humoral pathway should be further investigated as possible avenues of enhancing recovery after surgery, and reducing postoperative complications.

Electro-acupuncture to prevent prolonged postoperative ileus: A randomized clinical trial

AIM: To examine whether acupuncture can prevent prolonged postoperative ileus (PPOI) after intraperitoneal surgery for colon cancer.

METHODS: Ninety patients were recruited from the Fudan University Cancer Hospital, Shanghai, China. After surgery, patients were randomized to receive acupuncture (once daily, starting on postoperative day 1, for up to six consecutive days) or usual care. PPOI was defined as an inability to pass flatus or have a bowel movement by 96 h after surgery. The main outcomes were time to first flatus, time to first bowel movement, and electrogastroenterography. Secondary outcomes were quality of life (QOL) measures, including pain, nausea, insomnia, abdominal distension/fullness, and sense of well-being.

RESULTS: No significant differences in PPOI on day 4 (P = 0.71) or QOL measures were found between the groups. There were also no group differences when the data were analyzed by examining those whose PPOI had resolved by day 5 (P = 0.69) or day 6 (P = 0.88). No adverse events related to acupuncture were reported.

CONCLUSION: Acupuncture did not prevent PPOI and was not useful for treating PPOI once it had developed in this population.

Adynamic ileus and acute colonic pseudo-obstruction occurring after cesarean section in patients with massive peripartum hemorrhage

The clinical histories (including radiographs) of 4 patients who suffered from significant adynamic ileus or acute colonic pseudo-obstruction after cesarean section are presented. The main manifestations were vomiting, severe colicky pain, and abdominal distension. These can occur immediately after or within 2 days of the operation. Based on our experience, the risk factors for the development of adynamic ileus are significant peripartum hemorrhage leading to unstable hemodynamic status, severe constipation, use of meperidine for pain relief, and overt bowel manipulation. Mild enema and metoclopramide seem to be helpful in facilitating its resolution. Here, we examine how to differentiate mechanical bowel obstruction from adynamic ileus and look at how to prevent the occurrence of adynamic ileus while minimizing its severity and shortening its clinical course.

Pharmacologic Options to Prevent Postoperative Ileus

Objective:

To summarize the evidence on pharmacologic options in preventing postoperative ileus (POI).

Data Sources:

The Cochrane Database of Reviews and OVID databases and Food and Drug Administration (FDA) Web site were searched (1950–April 2009) using the term postoperative ileus.

Study Selection and Data Extraction:

Meta-analyses and randomized controlled trials were included for review. The FDA Web site was searched for clinical reviews and label information for drugs indicated for the prevention of POI.

Data Synthesis:

Three meta-analyses, 2 on gum-chewing and 1 on alvimopan, and 18 clinical trials were identified. Only gum chewing and alvimopan were effective in preventing POI. Gum chewing reduced the time to first flatus and bowel movement (weighted mean difference 21h, p = 0.0006 and 33h; p = 0.0002, respectively). In one meta-analysis, gum chewing significantly reduced length of stay (LOS) by 2.4 days (p < 0.00001) but this was not replicated in the second meta-analysis. Alvimopan shortened the time to reach a composite endpoint of solid food intake, plus/minus flatus, and bowel movement (93 vs 105 h; p < 0.001). A higher incidence of myocardial infarction was observed in a 12-month study of alvimopan for the treatment of opioid-induced bowel dysfunction, but not in studies in patients undergoing bowel resection. Alvimopan decreased the time to written hospital discharge order (hazard ratio 1.35; p<0.01), while the significance of a reduction in LOS (0.2–1.3 days) was not reported.

Conclusions:

Gum chewing and alvimopan are effective in preventing POI, but given safety concerns and higher cost with alvimopan, gum chewing may be preferred.

Peripherally acting mu-opioid receptor antagonists and postoperative ileus: mechanisms of action and clinical applicability

Postoperative ileus (POI), a transient cessation of coordinated bowel function after surgery, is an important health care problem. The etiology of POI is multifactorial and related to both the surgical and anesthetic pathways chosen. Opioids used to manage surgical pain can exacerbate POI, delaying gastrointestinal (GI) recovery. Peripherally acting mu-opioid receptor (PAM-OR) antagonists are designed to mitigate the deleterious effects of opioids on GI motility. This new class is investigational for POI management with the goal of accelerating the recovery of upper and lower GI tract function after bowel resection. In this review, we summarize the mechanisms by which POI occurs and the role of opioids and opioid receptors in the enteric nervous system, discuss the mechanism of action of PAM-OR antagonists, and review clinical pharmacology and Phase II/III POI trial results of methylnaltrexone and alvimopan. Finally, the role of anesthesiologists in managing POI in the context of a multimodal approach is discussed.

Novel opioid antagonists for opioid-induced bowel dysfunction and postoperative ileus

Peripherally acting mu-opioid receptor antagonists methylnaltrexone and alvimopan are a new class of drugs designed to reverse opioid-induced side-effects on the gastrointestinal system without compromising pain relief. This article gives an overview of the pharmacology, the efficacy, and adverse effects of these drugs. Both compounds seem to be generally well tolerated and effective for the treatment of opioid-related bowel dysfunction and postoperative ileus. Methylnaltrexone recently received approval by the US Food and Drug Administration (FDA) and the European Medicines Agency for treatment of opioid-related bowel dysfunction in patients with advanced illness. Alvimopan was recently approved by the FDA for treatment of postoperative ileus, but the use of the drug is restricted to inpatients because it has been associated with an increased rate of myocardial infarction. Further research should assess the effectiveness and safety of these drugs in clinical practice.

Development of peripheral opioid antagonists' new insights into opioid effects

The recent approval by the US Food and Drug Administration of 2 medications--methylnaltrexone and alvimopan--introduces a new class of therapeutic entities to clinicians. These peripherally acting mu-opioid receptor antagonists selectively reverse opioid actions mediated by receptors outside the central nervous system, while preserving centrally mediated analgesia. Methylnaltrexone, administered subcutaneously, has been approved in the United States, Europe, and Canada. In the United States, it is indicated for the treatment of opioid-induced constipation in patients with advanced illness (eg, cancer, AIDS) who are receiving palliative care, when response to laxative therapy has not been sufficient. Alvimopan, an orally administered medication, has been approved in the United States to facilitate recovery of gastrointestinal function after bowel resection and primary anastomosis. Clinical and laboratory studies performed during the development of these drugs have indicated that peripheral receptors mediate other opioid effects, including decreased gastric emptying, nausea and vomiting, pruritus, and urinary retention. Laboratory investigations with these compounds suggest that opioids affect fundamental cellular processes through mechanisms that were previously unknown. These mechanisms include modifications of human immunodeficiency virus penetration, tumor angiogenesis, vascular permeability, and bacterial virulence.

Regulation of enteric functions by adenosine: pathophysiological and pharmacological implications

The wide distribution of ATP and adenosine receptors as well as enzymes for purine metabolism in different gut regions suggests a complex role for these mediators in the regulation of gastrointestinal functions. Studies in rodents have shown a significant involvement of adenosine in the control of intestinal secretion, motility and sensation, via activation of A1, A2A, A2B or A3 purinergic receptors, as well as the participation of ATP in the regulation of enteric functions, through the recruitment of P2X and P2Y receptors. Increasing interest is being focused on the involvement of ATP and adenosine in the pathophysiology of intestinal disorders, with particular regard for inflammatory bowel diseases (IBDs), intestinal ischemia, post-operative ileus and related dysfunctions, such as gut dysmotility, diarrhoea and abdominal discomfort/pain. Current knowledge suggests that adenosine contributes to the modulation of enteric immune and inflammatory responses, leading to anti-inflammatory actions. There is evidence supporting a role of adenosine in the alterations of enteric motor and secretory activity associated with bowel inflammation. In particular, several studies have highlighted the importance of adenosine in diarrhoea, since this nucleoside participates actively in the cross-talk between immune and epithelial cells in the presence of diarrhoeogenic stimuli. In addition, adenosine exerts complex regulatory actions on pain transmission at peripheral and spinal sites. The present review illustrates current information on the role played by adenosine in the regulation of enteric functions, under normal or pathological conditions, and discusses pharmacological interventions on adenosine pathways as novel therapeutic options for the management of gut disorders and related abdominal symptoms.