Chewing gum in preventing postoperative ileus in women undergoing caesarean section: a systematic review and meta-analysis of randomised controlled trials

Acute colonic pseudo-obstruction post-cesarean section is not a benign entity: A case series and review of the literature

Acute colonic pseudo-obstruction (ACPO) is an infrequent occurrence after cesarean section. Anecdotal evidence suggests that the clinical course of ACPO in the obstetric setting is different to that seen in non-pregnant adult patients with ACPO secondary to alternative causes, such as systemic illnesses, the use of certain medications, and after non-abdominal surgery. The risk of progression to ischemia and perforation, as well as the need for emergency surgery, appears to be higher after cesarean section. Here we describe the clinical course of ACPO in four patients after cesarean section from our institution, followed by a review of the literature and a discussion of the important issues surrounding this condition in the postpartum time period. The findings from our cohort of patients and the reports from the medical literature support a hands-on combined approach from a group of specialists including obstetricians, surgeons, radiologists, and enterostomal therapists. Immediate imaging followed by regular observation is mandatory for any patient being managed conservatively. Early use of endoscopic decompression should be considered for patients who are not resolving with a conservative approach. Clinical signs of peritonism or radiological signs of ischemia or perforation in patients with ACPO mandate immediate surgical intervention. Appropriate postoperative care is necessary to deal with the complex physiological and psychological consequences of emergency surgery and potential stoma formation so soon after cesarean section.

Chewing gum base: A comprehensive review of composition, production, and assessment methods: Advances and approaches in biodegradability

The gum base mass is a colloidal system and the main component of chewing gum; which is an inert, non-nutritious, indigestible, and insoluble part of chewing gum, therefore this substance does not dissolve in the mouth when chewed. The gum base plays the most crucial role in determining the mechanical properties, flexibility, and overall quality of chewing gum. Moreover, it acts as a delivery system to transport sweeteners, flavorings, and other ingredients in chewing gum. Despite the massive market for chewing gum and the provision of a list of the main ingredients in gum base by the Code of Federal Regulations and some international organizations, there is a lack of information about chewing gum base and its compositions in the literature. Therefore, the purpose of this review is to present an overview of the characteristics, ingredients and applications, production process, assessment, and modification methods of the gum base along with the advances and approaches in biodegradability. Biodegradability concerns play a promoting role in the research and development of chewing gum and its applications in the food industry, medical and dental sectors. Reviewing previous studies can surely help for faster development of this path.

Effect of Chewing Gum on Gastrointestinal Function Recovery After Surgery of Gynecological Cancer Patients at Rajavithi Hospital: A Randomized Controlled Trial

Objective:

To evaluate the efficacy of postoperative gum-chewing compare with routine postoperative care on the recovery of gastrointestinal function after comprehensive surgical staging for gynecological cancer.

Materials and Methods:

A total of 82 patients who underwent comprehensive surgical staging for gynecological cancer at Rajavithi Hospital between October 1st, 2018 and June 30th, 2019 were randomly allocated into two groups: Gum-chewing group (n=40) and control group (n=42). In the gum-chewing group, patients were assigned to chew sugar-free gum for 30 minutes starting from the first postoperative morning then every 8 hours until the first passage of flatus. In the control group, patients have received routine postoperative care. The primary endpoint was time to first flatus after surgery. The secondary endpoints were time to first bowel sound, time to first defecation, time to first walk, postoperative analgesia and anti-emetic drug requirement, ileus symptoms, length of a hospital stay, and potential adverse events of gum-chewing, including dry mount, choking, and aspiration.

Results:

Chewing gum was statistically significant in reducing time to first flatus compared with routine postoperative care (median 24.7 (range 2.2-86.5) vs 35.4 (range 7.2-80.9) hours, p=0.025). The length of a hospital stay was also significantly shorter in the gum-chewing group (median 3.0 (range 1.0-8.8) vs 3.5 (range 1.8-50.0) days, p=0.023). There were no significant differences in time to first bowel sound, time to first defecation, time to first walk, postoperative analgesia and anti-emetic drug requirement, and ileus symptoms between both two groups. No adverse events related to postoperative gum-chewing were observed.

Conclusion:

Gum-chewing was associated with early recovery of gastrointestinal function in patients undergoing surgery for gynecological cancer. It is an inexpensive and physiologic intervention that appears to be reasonably safe and should be recommended as an adjunct in postoperative care of gynecological cancer surgery.

The Use of Coffee to Decrease the Incidence of Postoperative Ileus: A Systematic Review and Meta-Analysis

PURPOSE

To investigate the efficacy of providing coffee to elective abdominal surgery patients, immediately postoperatively, to lessen postoperative ileus.

DESIGN

A systematic review with meta-analysis of six randomized controlled trials published since 2012.

METHODS

Methodological quality was evaluated using the Cochrane guidelines. The Grading of Recommendations, Assessment, Development, and Evaluations assessment tool evaluated the quality of the evidence. Subgroup analyses were completed if the I² statistic demonstrated heterogeneity (greater than 50%).

FINDINGS

Coffee was statistically significant in shortening the time between surgery and the first passage of stool (mean difference, -9.38; 95% confidence interval, -17.60 to -1.16; P = .03). Although not statistically significant (P = .20), the overall effect favored shorter hospital stays for those patients receiving coffee.

CONCLUSIONS

The current systematic review and meta-analysis suggests that coffee given as early as 2 hours postoperatively decreases time to first bowel movement. In addition, patients tolerated solid food faster and were discharged sooner when given coffee immediately postoperatively.

Incidence and Effects of Feeding Intolerance in Trauma Patients

BACKGROUND

Although feeding intolerance is a common complication in trauma patients, the incidence, development, and effects are poorly understood.

METHODS

We performed a retrospective study in which trauma patients were classified as having feeding intolerance based on time to reach feeding goal. Subsequently, we sorted patients by gastric residual volumes (GRVs) or symptoms of slowed gastrointestinal motility.

RESULTS

One-third of trauma patients experienced delayed time to reach feeding goal after diet initiation. Delayed feeding was associated with prolonged intensive care unit (ICU) stays, increased readmission rates, and increased incidence of sepsis. Patients with elevated GRV (>500 mL) had significantly prolonged ICU and hospital stays and increase incidence of sepsis. Patients with >2 symptoms of slowed gastrointestinal motility had prolonged ICU and hospital stays, delayed time to reach feeding goals, significantly increased readmission rates, increased incidence of infectious and thromboembolic complications and sepsis, decreased serum prealbumin levels, and increased CRP levels.

CONCLUSION

Decreased gastrointestinal motility in trauma patients is associated with worse outcomes and increased systemic inflammation.

The effect of gum chewing on the return of bowel motility after planned cesarean delivery: a randomized controlled trial

Objective: To endorse the impact of chewing gum on the intestinal functions' restoration, hospital stay and gastrointestinal complications after planned cesarean delivery (CD).Methods: Women aged between 20 and 35 years scheduled for planned CD; either first or repeated, with term, singleton, viable and healthy pregnancy at obstetrics and gynecology department, Armed Forces Hospital Southern Region, Khamis Mushayt, Saudi Arabia were invited to participate and randomized if eligible into three groups. The first group chewed sugar-free gum 2 h after recovery at least for half an hour and at 2-h interval during daytime. The second group received oral fluids 6 h postoperatively, while the third group was the control group. The primary outcome measure was the time to first passage of stool. The secondary outcomes included the time of the first passage of flatus, the first hearing of normal intestinal sounds, the duration of hospital stay the duration of parenteral therapy by intravenous fluids, the time of initiating breast-feeding and the cost of hospital stay. The study was prospectively registered at ClinicalTrials.gov (NCT02386748).Results: The study included 372 women randomized into three groups (124 women in each group). Chewing gum significantly improved intestinal recovery with faster onset of bowel movements, first audible intestinal sounds, passage of flatus and passage of stool (p = .0001). It was associated with significantly shorter duration of hospital stay and parenteral therapy duration (p = .0001). Abdominal distension, vomiting and ileus postoperatively were significantly higher in nonchewing gum groups. Neither paralytic ileus nor side effects were recorded with gum use.Conclusion: Chewing gum, within 2 h postoperatively, is a simple, safe and well-tolerated intervention that can boost rapid intestinal recovery and shorten hospital stay after planned cesarean deliveries.

Gum chewing and bowel function after Caesarean section under spinal anesthesia

Objective:

To determine the effect of gum chewing on bowel function postoperatively in women after cesarean delivery under spinal anesthesia.

Methods:

This semi-experimental study was conducted at Near East University Hospital Obstetrics and Gynecology Clinic in Turkish Republic of Northern Cyprus with 45 women in both the +experimental and control groups, between October 2016 and June 2017. The women in the experimental group chewed gum two hours after surgery until gut sounds were heard and nutrition was given orally.

Results:

The mean age of the women was 30.20 ± 4.88 in the experimental group and 30.85 ± 4.47 in the control group. In the control group, the mean time of flatulation was 26.33 ± 7.54 hours, whereas the mean time was 13.44 ± 6.56 hours in the experimental group. The mean duration to the hearing of intestinal sounds was 16.35 ± 5.20 hours in the control group and 12.62 ± 7.73 hours in the experimental group.

Conclusion:

The results of the present study indicate that sugar free gum chewing in the post-operative period which is cesarean section under spinal anesthesia shortened the duration of the intestinal movement, the time of first flatulation, and discharge time.

A Prospective Single-blind Randomized Controlled Trial of Chewing Gum on Bowel Function Recovery After Posterior Spinal Fusion Surgery for Adolescent Idiopathic Scoliosis

PURPOSE

To evaluate the effectiveness of chewing gum on promoting bowel function recovery in adolescent idiopathic scoliosis patients undergoing surgical correction.

MATERIALS AND METHODS

Adolescent idiopathic scoliosis patients scheduled for posterior spinal fusion surgery at our institution were randomized to either group 1 (chewing gum) or group 2 (control). The primary endpoints were time to flatus, time to bowel movement, length of hospital stay, and time to liquid or solid. The secondary endpoints were postoperative opioid consumption, incidence of complications, pain scores, and nausea scores. In addition, a meta-analysis of available data from the literature was performed identifying 2 studies with quantitative data on the efficacy of gum chewing after scoliosis correction surgery.

RESULTS

In total, 125 patients (63 gum; 62 control) were included in our analysis after randomization. There was no significant difference in time to first flatus (P=0.087), time to bowel movement (P=0.307), time to liquid or solid, length of postoperative hospital stay (P=0.954), postoperative complications, opioid consumption, and postoperative nausea scores between the 2 groups. The postoperative pain scores on postoperative day 1 were significantly lower (P=0.027). There was a significant decrease in the time to the first flatus for patients having selective thoracic fusion in both groups than those having fusion to lumbar spine. Meta-analysis also indicated there was no significant difference in outcomes of bowel function between the 2 groups.

CONCLUSIONS

Our institutional data and meta-analysis collaboratively suggested that chewing gum did not hasten the return of bowel function.

Effect of chewing gum on gastrointestinal function after gynecological surgery: A systematic literature review and meta-analysis

AIM

Recently, several randomized controlled trials (RCT) reported the effect of chewing gum on gastrointestinal function after gynecological surgery; however, these results are inconsistent. The aim of this study was to systematically analyze the effect of chewing gum on postoperative gastrointestinal function and complications in women undergoing gynecological surgery.

METHODS

Pumbed, Embase, Cochrane Library, Web of Science, Chinese Wanfang databases, China National Knowledge Infrastructure and http://clinicaltrials.gov were searched from inceptions to April 30, 2017. Studies including chewing gum's impact on postoperative gastrointestinal function or complications were evaluated. Two authors individually performed data extraction from 10 RCT. Weighted mean difference (WMD) and odds ratio (OR) were used.

RESULTS

Contrasting the group of standard postoperative care, the gum chewing group had a lower duration from the end of operation to first aerofluxus (WMD -7.55, 95%CI: -10.99 to -4.12); first intestinal sounds (WMD -6.20, 95%CI: -8.14 to -4.27); first defecation (WMD -12.24, 95%CI: -18.47 to -6.01); hospitalization duration (WMD -0.72. 95%CI -1.19 to -0.25); and lower incidence of nausea (OR 0.45, 95%CI: 0.29 to 0.69), vomiting (OR 0.38, 95%CI: 0.22 to 0.68) and postoperative ileus (OR 0.25, 95%CI: 0.14 to 0.44).

CONCLUSION

Chewing gum is an effective measure to ameliorate gastrointestinal function and decrease complications after gynecological surgery.

Usage of Chewing Gum in Posterior Spinal Fusion Surgery for Adolescent Idiopathic Scoliosis: A Randomized Controlled Trial

STUDY DESIGN

Randomized controlled trial.

OBJECTIVE

The present study investigated the effectiveness of chewing gum on promoting faster bowel function and its ability to hasten recovery for patients with adolescent idiopathic scoliosis (AIS) after posterior spinal fusion (PSF) surgery.

SUMMARY OF BACKGROUND DATA

Sham feeding with chewing gum had been reported to reduce the incidence of postoperative ileus by accelerating recovery of bowel function.

METHODS

We prospectively recruited and randomized 60 patients with AIS scheduled for PSF surgery into treatment (chewing gum) and control group. The patient-controlled anesthesia usage, wound pain score, abdominal pain score, nausea score, and abdominal girth were assessed and recorded at 12, 24, 36, 48, and 60 hours postoperatively. The timing for the first fluid intake, first oral intake, sitting up, walking, first flatus after surgery, first bowel opening after surgery, and duration of hospital stay were also assessed and recorded.

RESULTS

We found that there were no significant differences (P > 0.05) in patient-controlled anesthesia usage, wound pain score, abdominal pain score, nausea score, and abdominal girth between treatment (chewing gum) and control groups. We also found that there were no significant difference (P > 0.05) in postoperative recovery parameters, which were the first fluid intake, first oral intake, sitting up after surgery, walking after surgery, first flatus after surgery, first bowel opening after surgery, and duration of hospital stay between both groups. The wound pain was the worst at 12 hours postoperatively, which progressively improved in both groups. The abdominal pain progressively worsened to the highest score at 48 hours in the treatment group and 36 hours in the control group before improving after that. The pattern of severity and recovery of wound pain and abdominal pain was different.

CONCLUSION

We found that chewing gum did not significantly reduce the abdominal pain, promote faster bowel function, or hasten patient recovery.

LEVEL OF EVIDENCE

1.

Chewing gum improves postoperative recovery of gastrointestinal function after cesarean delivery: a systematic review and meta-analysis of randomized trials

OBJECTIVE

To examine whether chewing gum hastens the return of gastrointestinal function after a cesarean delivery.

METHODS

All randomized controlled trials comparing the use of chewing gum in the immediate postoperative recovery period (i.e. intervention group) with a control group were included in the meta-analysis. The primary outcome was the time to first flatus in hours. Meta-analysis was performed using the random effects model of DerSimonian and Laird, to produce summary treatment effects in terms of mean difference (MD) or relative risk (RR) with 95% confidence interval (CI).

RESULTS

Seventeen trials, including 3041 women, were analyzed. Trials were of moderate to low quality with different inclusion criteria. In most of the included trials chewing gum was given right after delivery, three times a day for 30 min each and until the first flatus. Women who were randomized to the chewing gum group had a significantly lower mean time to first flatus (MD - 6.49 h, 95%CI -8.65 to -4.33), to first bowel sounds (MD - 8.48 h, 95%CI -9.04 to -7.92), less duration of stay (MD - 0.39 days, 95%CI -0.78 to -0.18), lower time to first feces (MD - 9.57 h, 95% CI -10.28 to 8.87) and to the first feeling of hunger (MD - 2.89 h, 95%CI -4.93 to -0.85), less number of episodes of nausea or vomiting (RR 0.33, 95%CI 0.12 to 0.87), less incidence of ileus (RR 0.39, 95%CI 0.19 to 0.80) and significantly higher satisfaction.

CONCLUSIONS

Gum chewing starting right after cesarean delivery three times a day for about 30 min until the first flatus is associated with early recovery of bowel motility. As this is a simple, generally inexpensive intervention, providers should consider implementing cesarean postoperative care with gum chewing.

Chewing gum for intestinal function recovery after caesarean section: a systematic review and meta-analysis

Background

Gum chewing has been reported to enhance the intestinal function recovery after caesarean section, current perspectives and practice guidelines vary widely on the use of gum chewing, more studies on the role of gum chewing after caesarean section are needed.

Methods

We performed a comprehensive, systematic meta-analysis of randomized controlled trials (RCTs) on the efficacy of gum chewing after caesarean section. Studies were identified by searching EMBASE et al database (until June 30, 2016). Summary odd ratios or weighted mean differences with 95% confidence intervals were calculated for each outcome with fixed- or random-effects model.

Results

Ten RCTs with a total of 1659 women were included in our meta-analysis. Gum chewing provided significant benefits in reducing the time to first passage of flatus, first defecation, first bowel sound, first bowel movement and the length of hospital stay, but not in the time to first feeling of hunger.

Conclusions

Gun chewing hastens the intestinal function recovery after caesarean section and offers a safe and inexpensive option. High-quality and larger-scale RCTs are still warranted to clarify the role of gum chewing in intestinal function recovery after caesarean section.

Chewing gum for enhancing early recovery of bowel function after caesarean section

BACKGROUND

Caesarean sections (CS) are the most frequent major surgery in the world. A transient impairment of bowel motility is expected after CS. Although this usually resolves spontaneously within a few days, it can cause considerable discomfort, require symptomatic medication and delay hospital discharge, thus increasing costs. Chewing gum in the immediate postoperative period is a simple intervention that may be effective in enhancing recovery of bowel function in other types of abdominal surgeries.

OBJECTIVES

To assess the effects of chewing gum to reduce the duration of postoperative ileus and to enhance postoperative recovery after a CS.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (20 June 2016), LILACs (20 June 2016), ClinicalTrials.gov (20 June 2016), WHO International Clinical Trials Registry Platform (ICTRP) (20 June 2016) and the reference lists of retrieved studies.

SELECTION CRITERIA

All randomised controlled trials comparing chewing gum versus usual care, for women in the first 24 hours after a CS. We included studies published in abstract form only.Quasi-randomised, cross-over or cluster-randomised trials were not eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies for inclusion, extracted data and assessed the risk of bias following standard Cochrane methods. We present dichotomous outcome results as risk ratio (RR) with 95% confidence intervals (CI) and continuous outcome results as mean differences (MD) and 95% CI. We pooled the results of similar studies using a random-effects model in case of important heterogeneity. We used the GRADE approach to assess the overall quality of evidence.

MAIN RESULTS

We included 17 randomised trials (3149 participants) conducted in nine different countries. Seven studies (1325 women) recruited exclusively women undergoing elective CS and five studies (833 women) only included women having a primary CS. Ten studies (1731 women) used conventional feeding protocols (nil by mouth until the return of intestinal function). The gum-chewing regimen varied among studies, in relation to its initiation (immediately after CS, up to 12 hours later), duration of each session (from 15 to 60 minutes) and number of sessions per day (three to more than six). All the studies were classified as having a high risk of bias due to the nature of the intervention, women could not be blinded and most of the outcomes were self-reported.Primary outcomes of this review: for the women that chewed gum, the time to passage of first flatus was seven hours shorter than those women in the 'usual care' control group (MD -7.09 hours, 95% CI -9.27 to -4.91 hours; 2399 women; 13 studies; random-effects Tau² = 14.63, I² = 95%, very low-quality evidence). This effect was consistent in all subgroup analyses (primary and repeat CS, time spent chewing gum per day, early and conventional feeding protocols, elective and non-elective CS and time after CS when gum-chewing was initiated). The rate of ileus was on average over 60% lower in the chewing-gum group compared to the control (RR 0.39, 95% CI 0.19 to 0.80; 1139 participants; four studies; I² = 39%, low-quality evidence). Tolerance to gum-chewing appeared to be high. Three women in one study complained about the chewing gum (but no further information was provided) and none of the studies reported adverse effects (eight studies, 925 women, low-quality evidence).Secondary outcomes of this review: the time to passage of faeces occurred on average nine hours earlier in the intervention group (MD -9.22 hours, 95% CI -11.49 to -6.95 hours; 2016 participants; 11 studies; random-effects Tau² = 12.53, I² = 93%, very low-quality evidence). The average duration of hospital stay was shorter in the intervention compared to the control group (MD -0.36 days, 95% CI -0.53 to -0.18 days; 1489 participants; seven studies; random-effects Tau² = 0.04, I² = 92%). The first intestinal sounds were heard earlier in the intervention than in the control group (MD -4.56 hours, 95% CI -6.18 to -2.93 hours; 1729 participants; nine studies; random-effects Tau² = 5.41, I² = 96%). None of the studies assessed women's satisfaction in relation to having to chew gum. The need for analgesia or antiemetic agents did not differ between the intervention and control groups (average RR 0.50, 95% CI 0.12 to 2.13; 726 participants; three studies; random-effects Tau² = 0.79, I² = 69%).

AUTHORS' CONCLUSIONS

This review found 17 randomised controlled trials (involving 3149 women). We downgraded the quality of the evidence for time to first passage of flatus and of faeces and for adverse effects/intolerance to gum chewing because of the high risk of bias of the studies (due to lack of blinding and self-report). For time to first flatus and faeces, we downgraded the quality of the evidence further because of the high heterogeneity in these meta-analyses and the potential for publication bias based on the visual inspection of the funnel plots. The quality of the evidence for adverse effects/tolerance to gum chewing and for ileus was downgraded because of the small number of events. The quality of the evidence for ileus was further downgraded due to the unclear risk of bias for the assessors evaluating this outcome.The available evidence suggests that gum chewing in the immediate postoperative period after a CS is a well tolerated intervention that enhances early recovery of bowel function. However the overall quality of the evidence is very low to low.Further research is necessary to establish the optimal regimen of gum-chewing (initiation, number and duration of sessions per day) to enhance bowel function recovery and to assess potential adverse effects of and women's satisfaction with this intervention. New studies also need to assess the compliance of the participants to the recommended gum-chewing instructions. Future large, well designed and conducted studies, with better methodological and reporting quality, will help to inform future updates of this review and enhance the body of evidence for this intervention.

Chewing gum for postoperative recovery of gastrointestinal function

BACKGROUND

Ileus commonly occurs after abdominal surgery, and is associated with complications and increased length of hospital stay (LOHS). Onset of ileus is considered to be multifactorial, and a variety of preventative methods have been investigated. Chewing gum (CG) is hypothesised to reduce postoperative ileus by stimulating early recovery of gastrointestinal (GI) function, through cephalo-vagal stimulation. There is no comprehensive review of this intervention in abdominal surgery.

OBJECTIVES

To examine whether chewing gum after surgery hastens the return of gastrointestinal function.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (via Ovid), MEDLINE (via PubMed), EMBASE (via Ovid), CINAHL (via EBSCO) and ISI Web of Science (June 2014). We hand-searched reference lists of identified studies and previous reviews and systematic reviews, and contacted CG companies to ask for information on any studies using their products. We identified proposed and ongoing studies from clinicaltrials.gov, World Health Organization (WHO) International Clinical Trials Registry Platform and metaRegister of Controlled Trials.

SELECTION CRITERIA

We included completed randomised controlled trials (RCTs) that used postoperative CG as an intervention compared to a control group.

DATA COLLECTION AND ANALYSIS

Two authors independently collected data and assessed study quality using an adapted Cochrane risk of bias (ROB) tool, and resolved disagreements by discussion. We assessed overall quality of evidence for each outcome using Grades of Recommendation, Assessment, Development and Evaluation (GRADE). Studies were split into subgroups: colorectal surgery (CRS), caesarean section (CS) and other surgery (OS). We assessed the effect of CG on time to first flatus (TFF), time to bowel movement (TBM), LOHS and time to bowel sounds (TBS) through meta-analyses using a random-effects model. We investigated the influence of study quality, reviewers' methodological estimations and use of Enhanced Recovery After Surgery (ERAS) programmes using sensitivity analyses. We used meta-regression to explore if surgical site or ROB scores predicted the extent of the effect estimate of the intervention on continuous outcomes. We reported frequency of complications, and descriptions of tolerability of gum and cost.

MAIN RESULTS

We identified 81 studies that recruited 9072 participants for inclusion in our review. We categorised many studies at high or unclear risk of the bias' assessed. There was statistical evidence that use of CG reduced TFF [overall reduction of 10.4 hours (95% CI: -11.9, -8.9): 12.5 hours (95% CI: -17.2, -7.8) in CRS, 7.9 hours (95% CI: -10.0, -5.8) in CS, 10.6 hours (95% CI: -12.7, -8.5) in OS]. There was also statistical evidence that use of CG reduced TBM [overall reduction of 12.7 hours (95% CI: -14.5, -10.9): 18.1 hours (95% CI: -25.3, -10.9) in CRS, 9.1 hours (95% CI: -11.4, -6.7) in CS, 12.3 hours (95% CI: -14.9, -9.7) in OS]. There was statistical evidence that use of CG slightly reduced LOHS [overall reduction of 0.7 days (95% CI: -0.8, -0.5): 1.0 days in CRS (95% CI: -1.6, -0.4), 0.2 days (95% CI: -0.3, -0.1) in CS, 0.8 days (95% CI: -1.1, -0.5) in OS]. There was statistical evidence that use of CG slightly reduced TBS [overall reduction of 5.0 hours (95% CI: -6.4, -3.7): 3.21 hours (95% CI: -7.0, 0.6) in CRS, 4.4 hours (95% CI: -5.9, -2.8) in CS, 6.3 hours (95% CI: -8.7, -3.8) in OS]. Effect sizes were largest in CRS and smallest in CS. There was statistical evidence of heterogeneity in all analyses other than TBS in CRS.There was little difference in mortality, infection risk and readmission rate between the groups. Some studies reported reduced nausea and vomiting and other complications in the intervention group. CG was generally well-tolerated by participants. There was little difference in cost between the groups in the two studies reporting this outcome.Sensitivity analyses by quality of studies and robustness of review estimates revealed no clinically important differences in effect estimates. Sensitivity analysis of ERAS studies showed a smaller effect size on TFF, larger effect size on TBM, and no difference between groups for LOHS.Meta-regression analyses indicated that surgical site is associated with the extent of the effect size on LOHS (all surgical subgroups), and TFF and TBM (CS and CRS subgroups only). There was no evidence that ROB score predicted the extent of the effect size on any outcome. Neither variable explained the identified heterogeneity between studies.

AUTHORS' CONCLUSIONS

This review identified some evidence for the benefit of postoperative CG in improving recovery of GI function. However, the research to date has primarily focussed on CS and CRS, and largely consisted of small, poor quality trials. Many components of the ERAS programme also target ileus, therefore the benefit of CG alongside ERAS may be reduced, as we observed in this review. Therefore larger, better quality RCTS in an ERAS setting in wider surgical disciplines would be needed to improve the evidence base for use of CG after surgery.

Nicotine gum chewing: a novel strategy to shorten duration of postoperative ileus via vagus nerve activation

Postoperative ileus (POI) is a transit cessation of bowel motility after surgery. Substantial evidences suggest that gum chewing accelerate the recovery of bowel motility after surgery. Perioperative nicotine administration reduces postoperative opioid use and prevents postoperative nausea and vomiting. Nicotine gum chewing combines stimulation of the cephalic-vagal reflex by gum chewing, and activation of the cholinergic anti-inflammatory pathway by nicotine administration. We therefore hypothesized that nicotine gum chewing reduces POI and improves patient outcomes such as shortening the length of hospitalization as well as saving medical costs. As nicotine gum is commercially available, inexpensive, and has been in use for many years without any severe side effects, it may have a wide clinical application in POI prevention.