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Preoperative gum chewing: forbidden, allowed or recommended?

Last post 04 Feb 2019, 12:23 PM by William Fawcett . 1 replies.
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  •  15 Jan 2019, 2:27 PM 2715

    • desgranges is not online. Last active: 07 Feb 2019, 8:42 AM Fran├žois-Pierrick DESGRANGES
    • Top 200 Contributor
    • Joined on 15 Jun 2012
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    Preoperative gum chewing: forbidden, allowed or recommended?

    Drs Fawcett and Thomas clearly addressed recent advances concerning preoperative fasting and the implications for the implementation of such recommendations in enhanced recovery after surgery (ERAS) programs [1]. However, the authors did not mention the minimal time interval that should be applied between gum chewing and induction of anaesthesia. This omission is probably due to the lack of current consensus among practice guidelines regarding this issue [2]. However, gum chewing has been reported to enhance gastric emptying while reducing patient discomfort and anxiety during the preoperative period [2]. Hence, preoperative gum chewing might be of interest to improve postoperative recovery.

    Recent literature suggests that postoperative gum chewing after digestive or gynaecologic surgery may offer an innovative intervention for improving postoperative gastrointestinal function recovery [2, 3]. Nevertheless, there is little evidence about the clinical impact of gum chewing during the postoperative period in terms of reductions in patient discomfort, complications and length of hospital stay [3]. The initiation of gum chewing during the immediate preoperative period, rather than during the hours after the surgical procedure, could lead to earlier resolution of ileus and improvement of postoperative recovery. To the best of our knowledge, the potential impact of gum chewing before surgery on postoperative outcome has never been evaluated.

    As mentioned by Drs Fawcett and Thomas in their review [1], antral ultrasonography has been proposed for the assessment of gastric content and volume in various surgical populations [4-6]. Using this tool, we have recently demonstrated in healthy volunteers that gum chewing was not associated with increased gastric fluid volume measured 2 hours after the oral intake of 250 ml of water [7]. Hence, preoperative chewing gum does probably not increase the risk of pulmonary aspiration of gastric content and could be considered as a safe practice.

    Future practice guidelines on preoperative fasting should give up-to-date recommendations concerning gum chewing that allow this practice during the hours before elective surgery. Such recommendations are probably a prerequisite for the initiation of future clinical trials assessing the potential benefits of preoperative gum chewing on postoperative outcomes after abdominal surgeries. In a few years, one cannot exclude the possibility that this practice could be recommended and integrated in different ERAS programs.


    F.-P. Desgranges

    D. Chassard

    L. Bouvet 

    Hospices Civils de Lyon, Femme Mère Enfant Teaching Hospital,

    Lyon, France.

    Email: fp_desgranges@yahoo.fr


    No external funding and no competing interests declared.



    1. Fawcett WJ, Thomas M. Pre-operative fasting in adults and children: clinical practive and guidelines. Anaesthesia 2019; 74: 83-8.
    2. Poulton TJ. Gum chewing during pre-anesthetic fasting. Pediatric Anesthesia 2012; 22: 288-96.
    3. Short V, Herbert G, Perry R, et al. Chewing gum for postoperative recovery of gastrointestinal function. Cochrane Database of Systematic Reviews 2015; 2: CD006506.
    4. Dupont G, Gavory J, Lambert P, et al. Ultrasonographic gastric volume before unplanned surgery. Anaesthesia 2017; 72: 1112-6.
    5. Gagey AC, de Queiroz Siqueira M, Monard C, et al. The effect of pre-operative gastric ultrasound examination on the choice of general anaesthetic induction technique for non-elective paediatric surgery. A prospective cohort study. Anaesthesia 2018; 73: 304-12.
    6. Desgranges FP, Gagey Riegel AC, Aubergy C, de Queiroz Siqueira M, Chassard D, Bouvet L. Ultrasound assessment of gastric contents in children undergoing elective ear, nose and throat surgery: a prospective cohort study. Anaesthesia 2017; 72: 1351-6.
    7. Bouvet L, Loubradou E, Desgranges FP, Chassard D. Effect of gum chewing on gastric volume and emptying: a prospective randomized crossover study. British Journal of Anaesthesia 2017; 119: 928-33.
  •  04 Feb 2019, 12:23 PM 2728 in reply to 2715

    Re: Preoperative gum chewing: forbidden, allowed or recommended?

    In reply to Desgranges et al. [1], whilst some may argue that chewing gum does not technically constitute food or drink, we agree this is very relevant to the whole concept of preoperative fasting.

    Early work suggested that chewing gum in both adults and children preoperatively patients may significantly increase gastric acid secretion and thus gastric fluid volumes (GFV)  [2,3]. Of note, however, is that in adults the gastric pH was unchanged [2] and in children gastric pH was actually increased [3]. Nevertheless, the increase in GFV is considered by some to place patients at greater risk of clinically significant pulmonary aspiration.

    As water is also ingested until 2 hours before surgery, a more clinically relevant study published by Lesgrange et al. investigated the effects of both water and chewing gum on GFV, which demonstrated that chewing gum neither delayed gastric emptying nor increased GFV [4].

    Mounting evidence supports gum chewing preoperatively without added risk to paediatric or adult patients [5], and we support this. However it may take some time for this to be reflected in other guidelines; for example the recent American Society of Anesthesiologists’ Task Force on Preoperative Fasting  guidelines do not specifically mention chewing gum at all [6].

    Postoperative gum chewing has been adressed elsewhere [7]. Its potential impact within ERAS programmes has been assessed alongside other pathways to improve gastrointestinal function and its use, whilst acknowledged to be safe, is not currently supported by the Society’s most recent colorectal guidelines, published last month [8]

    Finally, a vital, if obvious, practical point for consideration concerns the removal of chewing gum before the induction of anaesthesia to prevent airway obstruction; all the deaths reported by Mendelson’s landmark study were due to airway obstruction and not gastric acid aspiration [9]. A recent paper demonstrated that over a 5.5 year period, five cases were identified in which gum was not detected preoperatively and was later found in the patient’s mouth intraoperatively or postoperatively. The authors recommended that a specific question on checklists for chewing gum may therefore be required [10]. 

    W. J. Fawcett

    Royal Surrey County Hospital NHS Foundation Trust,

    Guildford, UK.

    M. Thomas

    Great Ormond Street Hospital for Children NHS Foundation Trust,

    London, UK.

    Email: wfawcett@nhs.net


    No external funding and no conflicts of interest declared.



    1. Fawcett WJ, Thomas M. Pre-operative fasting in adults and children. Anaesthesia 2019; 74: 83-8.
    2. Soreide E, Holst-Larsen H, Veel T, Steen PA. The effects of chewing gum on gastric content prior to induction of general anesthesia. Anesthesia & Analgesia1995; 80: 985-9
    3. Schoenfelder RC, Ponnamma CM, Freyle D, Wang SM, Kain ZN. Residual gastric fluid volume and chewing gum before surgery. Anesthesia & Analgesia 2006; 102: 415-7
    4. Bouvet L, Loubradou E, Desgranges FP, Chassard D. Effect of gum chewing on gastric volume and emptying: a prospective randomized crossover study. British Journal of Anaesthesia 2017; 119: 928-33.
    5. Smith I, Kranke P, Murat I et al. European Journal of Anaesthesiology 2011; 28: 556-69.
    6. American Society of Anesthesiologists. Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: application to healthy patients undergoing elective procedures. Anesthesiology 2017;126: 376-93
    7. Short V, Herbert G, Perry R, et al. Chewing gum for postoperative recovery of gastrointestinal function. Cochrane Database of Systematic Reviews 2015; 2: CD006506
    8. Gustafsson UO, Scott MJ, Hubner M et al. Guidelines for perioperative care in elective colorectal surgery: enhanced recovery after surgery (ERAS®) society recommendations: 2018. World Journal of Surgery 2019; 43: 659 -9.
    9. Mendelson CL. The aspiration of stomach contents into the lungs during obstetric anesthesia. American Journal of Obstetrics and Gynecology 1946; 52: 191–205
    10. Shanmugam S, Goulding G, Gibbs NM, Taraporewalla K, Culwick M. Chewing gum in the preoperative fasting period: an analysis of de-identified incidents reported to webAIRS. Anaesthesia & Intensive Care 2016; 44: 281-4.
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