Keywords: Nutrition/Nil by mouth/ Nursing Practice Fasting/Surgical care Review ●This article has been double-blind Nutrition peer reviewed Nurses need to understand why patients must be nil by mouth, be familiar with best practice and be able to educate patients in the procedure and the reasons for it Nil by mouth: best practice and patient education 5 key In this article... points Why patients should be nil by mouth before and after surgery Patients who are Best practice and how to educate patients 1to be nil by How to relieve patients’ discomfort when they are nil by mouth mouth need to be physically and psychologically Author Catherine Liddle is senior lecturer signs including hypotension, tachycardia, prepared for the at Birmingham City University. oliguria, confusion and a decreased level of period of fasting Abstract Liddle C (2014) Nil by mouth: consciousness. This, together with the psy- All staff should best practice and patient education. chosocial factors of fasting – being unable 2have a good Nursing Times; 110: 26, 12-14. to eat or drink like other patients – can understanding of Some patients need to stop eating and make being NBM an unpleasant experience. current fasting drinking, to be nil by mouth, at certain guidelines points in their care pathway for their own Preparing patients Communi- safety; their care will vary, depending on The multidisciplinary team should have a 3cation between individual needs. Nurses need adequate good knowledge and understanding of staff and patients is knowledge of NBM guidelines to know fasting guidelines so patients are given essential how to implement them and be able to accurate information, relevant informa- A nil-by-mouth educate patients. This article explains how tion is documented and local guidelines 4plan of care to care for patients who are NBM during are followed (Lorch, 2007; Royal College of and associated pre- or post-operative periods. Nursing, 2005). assessments Before admission, patients need to be should be atients are restricted from eating fully informed about fasting pre- and post- implemented, and drinking, commonly known operatively to: documented and as being nil by mouth (NBM), as » Ensure adherence; updated Pa result of a variety of conditions » Reduce the risk of surgery being Patient privacy, and at different times in their treatment delayed/cancelled; 5dignity, pathway, particularly during surgery. » Aid a smooth and rapid recovery. comfort and safety Conditions include non-functional Patients with a learning disability or must be maintained bowel, acute abdomen, dysphagia, uncon- cognitive impairment will need extra sup- at all times sciousness or reduced level of conscious- port to ensure they understand the impor- ness, and nausea or vomiting. The nursing tance and safety aspects of fasting. Patients care will vary for each, depending on the who are prepared are less prone to experi- length of time the patient will be NBM and encing anxiety and more likely to have a their individual circumstances. This reduced stress response to surgery (Var- article looks at caring for patients who are adhan et al, 2010). NBM before or after an operation. When a patient fasts in hospital for a Pre-operative fasting long time, problems may occur, typically: For decades, patients have fasted from » Dehydration; midnight or even longer for a morning the- » Malnutrition and electrolyte imbalance; atre list and from 6am if on the afternoon » Hypoglycaemia; list (Brady et al, 2010). This practice has » Nausea and vomiting. become ritualistic in clinical areas. The Older people, children, pregnant RCN (2005) published guidelines to change women and patients who are critically ill out-of-date and varied practice in the UK. are particularly vulnerable (Chand and Evidence-based pre-operative fasting is a Dabbas, 2007). When patients become medical and legal requirement to maintain Intravenous fluids may be required when

Alamy dehydrated, they display physiological patient safety. Unless it is for emergency patients exceed fasting times

12 Nursing Times 25.06.14 / Vol 110 No 26 / www.nursingtimes.net “Ensure patients are at the centre of your thinking” Tracy Mannix p28 surgery, patients should not be given an Box 1. Nil by mouth: consider how long the patient will be anaesthetic without a period of being guidance fasting before, during and after surgery. NBM; this reduces the risk of pulmonary National Institute of Health and Care aspiration if gastric contents are regurgi- Excellence (2006) guidance recommends tated. The gag, swallow and cough reflexes Patients can take the following before using a validated screening tool (such as usually protect the airway from aspiration being anaesthetised: the Malnutrition Universal Screening of food or fluids but, when patients are Tool). Screening should include: anaesthetised, these are suppressed to Adult » Assessment of body mass index; varying degrees (Brady et al, 2010). ● Water up to two hours before » Unintentional weight loss; Brady et al’s (2010) review of randomised ● Food up to six hours before » Time of unintentional reduced controlled trials suggested that patients nutritional intake or future impaired who drank clear fluids up to a few hours Child nutrient intake. before surgery were at no greater risk of ● Water and clear fluids up to two This is important to prevent surgery aspiration than in those who fasted from hours before being cancelled due to malnutrition and midnight; those who fasted for the shorter ● Breast milk up to four hours before related post-operative complications. period also had a lower gastric volume. ● Formula/cow’s milk or solids up to six Patients who have post-operative The RCN’s (2005) guideline states that hours before nausea, vomiting or a non-functioning gut prolonged fasting can increase the risk of due to gastrointestinal surgery can remain aspiration of stomach contents, leading to Source: Royal College of Nursing (2005) NBM for longer; in some cases, nutritional respiratory problems and possibly death. support may be required. Obesity, pregnancy, peptic ulcer, gastric NICE (2006) guidance provides flow- reflux, stress and pain place patients at a gastrointestinal motility and physiologic charts on when to consider oral, enteral higher risk of aspirating (Brady, 2010; RCN, gastric emptying”. and parenteral nutritional support pre- 2005). A surgeon or anaesthetist may When surgery is delayed, the guidelines operatively. A few surgical patients will request a longer fasting time for these recommend the surgical team consider have artificial feeding pre-operatively – patients (RCN, 2005). allowing adults some water to prevent those with severe weight loss, very low Jones and Swart’s (2013) Guidelines for the dehydration and relieve thirst; they do not, body mass index or a risk of post-operative Provision of Anaesthetic Services recommends however, stipulate how much water can be complications (Braga et al, 2009). Paren- patients with diabetes are fasted for the drunk. Staff should consider giving chil- teral nutrition will be considered for minimum amount of time, as “fasting, sur- dren a drink of water or another clear fluid; patients who are malnourished and have gical stress and inactivity can all have a neg- if the delay is to be longer than two hours, an “inadequate or unsafe enteral intake” or ative effect on blood-sugar control”, and one should definitely be given (RCN, 2005). a “non-functional inaccessible or perfo- are placed at the top of the operating list. Roberts’ (2013) literature search revealed rated gastrointestinal tract” (NICE, 2006). A safety alert (National Patient Safety that, despite best-practice guidelines, pre- Agency, 2011) reported the risk of harm to operative fasting times remain excessive. Post-operative care patients who are kept unintentionally NBM He recommended more detailed patient Fasting for prolonged periods. This was prompted literature, including the implications of Patients with a short fasting time are less by the case of a patient kept NBM for 10 extending fasting times and the possibility likely to experience post-operative nausea days awaiting a procedure. The alert of associated nausea and headaches. and vomiting and are more likely to have a underlines the fact that “vulnerability, Lorch (2007) undertook an action quicker and more comfortable post-opera- dehydration, malnutrition or complica- research study to improve the patient expe- tive recovery and experience (Chand and tions from omitted or delayed medication” rience and implement the RCN’s (2005) Dabbas, 2007). are intensified when a patient is exposed to guidelines. The outcome improved patient RCN (2005) guidelines state that as long long periods of being NBM. It concludes by and staff knowledge, improved patient as there are no contraindications, patients recommending that organisations: comfort and safety, ensured uniformity of can be offered and encouraged to drink » Assess for alternative methods of practice, improved communication fluids post-operatively. They say it may be hydration, nutrition and medication; between patients and staff, and avoided better for children to try breast milk or » Document a NBM care plan; the omission of prescribed medication. clear fluids first. This does not apply to » Communicate the patient’s NBM status patients who have had gastrointestinal or to all relevant staff. Pre-operative medication major abdominal surgery. Patients should be reviewed individu- Prescribed regular oral medication and pre- ally by nursing and medical staff to ensure medication, unless contraindicated and Enhanced recovery programme their NBM time is kept to a minimum. excepting oral hypoglycaemic medicines, The NHS Institute for Innovation and Nurses are pivotal in ensuring communi- should be administered pre-operatively to Improvement’s enhanced recovery pro- cation is maintained between theatre and avoid surgery being cancelled, for example gramme, launched in 2008, has been used ward staff and the patient. due to hypertension (Lorch, 2007; RCN, in many specialties. It aims to minimise The RCN (2005) published recommen- 2005). Adults can have up to 30ml of water the body’s stress response to anaesthesia dations for pre-operative fasting for and children up to 0.5ml/kg (up to 30ml) to and surgery, reducing post-operative healthy adults (Box 1). These advise that take the medication (RCN, 2005). recovery time so patients can be discharged sweets are classed as food and chewing earlier (Foss and Bernard, 2012; Slater, 2010). gum should be avoided on the day of sur- Risk assessment Key aspects are managing fluid balance gery; however, Poulton (2012) states “there Pre-operatively, a malnutrition risk assess- and fasting times, and ensuring patients do is evidence that gum chewing promotes ment should be performed, which should not become malnourished or dehydrated.

www.nursingtimes.net / Vol 110 No 26 / Nursing Times 25.06.14 13 Nursing Practice Review

Patients are given a clear, carbohydrate- Conclusion rich drink before midnight and a second Box 2. Oral effects Educational and clinical institutions must drink 2-3 hours before surgery to reduce of being nil by mouth work together to educate all healthcare their discomfort from fasting and pre- workers so patients have the best possible operative thirst and hunger (Brady et al, ● Dry mouth, throat and tongue care when they are NBM. Surgeons, nurses, 2010). The evidence suggests that carbohy- ● Difficulty in speaking theatre staff, students and housekeeping drate drinks pre-operatively result in a ● Saliva that feels thick and stringy staff need to follow the most recent guide- shorter stay in hospital due to a quicker ● Bad breath lines. Patients must be educated and kept return of bowel function, a reduced loss of ● Teeth that feel coated and unclean informed about their NBM status. The body mass and a decrease in post-operative ● Dry, cracked lips RCN (2005) guidelines inform practice; nausea and vomiting (Jones et al, 2011). local policies should reflect them. NT Fluids and diet are often reintroduced on the day of surgery to promote gut the sympathetic nervous system. References BAPEN (2011) British Consensus Guidelines on motility and reduce the risk of the patient In dehydrated patients, saliva secretion Intravenous Fluid Therapy for Adult Surgical developing an ileus (when peristalsis stops stops to conserve water (Jenkins et al, 2010). Patients. tinyurl.com/GIFTASUP-IV-FluidTherapy and the bowel ceases to function) (Var- Post-operatively, patients may remain Bisset S, Preshaw P (2011) Guide to providing mouth care for older people. Nursing Older People; adhan et al, 2010). NBM for several hours or longer and be 23: 10, 14-21. prone to xerostomia due to dehydration, Brady MC et al (2010) Preoperative fasting for adults Intravenous therapy oxygen therapy and side-effects of the to prevent perioperative complications. Cochrane Nurses need to know when patients exceed anaesthetic. They will need frequent oral Database of Systematic Reviews; 4: CD004423. Braga M et al (2009) Espn guidelines on parenteral their fasting time and discuss introducing care (Bisset and Preshaw, 2011). nutrition: surgery. Clinical Nutrition; 28, 378-386. intravenous fluids with doctors. BAPEN Mouthwash should be available for Chand M, Dabbas N (2007) Nil by mouth: a (2011) offers recommendations on pre-, patients; they may prefer to use their own misleading statement. Journal of Perioperative Practice; 17: 8, 366-371. intra- and post-operative fluid manage- but those that contain alcohol can have a Dingwall L (2010) Essential Clinical Skills for ment in adult surgical patients. Mechan- drying effect on the mouth. Chlorhexidine Nurses. London: Wiley Blackwell. ical bowel preparation is avoided where mouthwashes can reduce the level of plaque Foss M, Bernard H (2012) Enhanced recovery after surgery: implications for nurses. British Journal of possible but, if it is necessary, it is common and bacteria but should not be used more Nursing; 21: 4, 221-223. for an electrolyte imbalance and dehydra- than twice a day because of their alcohol Jenkins et al (2010) Anatomy and Physiology from tion to occur; this should be corrected with content. Dingwall (2010) suggests using Science to Life. New Jersey: Wiley, IV fluid and closely monitored (BAPEN, 0.9% saline as this does not affect the pH of Jones C et al (2011) The role of carbohydrate drinks in pre-operative nutrition for elective 2011; National Confidential Enquiry into saliva and is flavourless. Lemon and glyc- colorectal surgery. Annals of the Royal College of Patient Outcome and Death, 2011). erine swabs are discouraged – the lemon’s Surgeons of England; 93:7, 504–507. Nursing care should include mainte- acidity damages tooth enamel and glycerine Jones K, Swart M (2013) Anaesthetic services for pre-operative assessment and preparation. In: nance of an accurate fluid balance chart; draws fluid away from the tissues, reducing Royal College of Anaesthetists Guidelines for the cannula care should include the use of a saliva production. Glycerol or petroleum Provision of Anaesthetic Services. www.rcoa.ac.uk/ phlebitis scale to prompt action. jelly can be applied to the lips but can feel system/files/GPAS-2013-FULL_0.pdf Lorch A (2007) Implementation of fasting sticky; patients’ own lip balm or a water- guidelines through nursing leadership. Nursing Fluid balance soluble gel can be used (Dingwall, 2010). Times; 103: 18; 30-31. Patients receiving additional fluid or Patients who wear dentures may prefer National Confidential Enquiry into Patient nutritional support should have their fluid to keep them in for as long as possible, Outcome and Death (2011) Knowing the Risks. A Review of the Peri-Operative Care of Surgical balance recorded on a fluid balance chart sometimes until induction of the anaes- Patients. NCEPOD. tinyurl.com/NCEPOD-2011 so it can be assessed. This should include: thesia; however, a dry mouth can make National Institute for Health and Care Excellence » Urine output (minimum of 0.5ml/kg/hr); wearing them uncomfortable. (2014) The Management of Pressure Ulcers in Primary and Secondary Care. www.nice.org.uk/cg179 » Any other output; National Institute for Health and Care Excellence » All IV fluids; Pressure ulcers (2006) Nutrition Support in Adults. Oral Nutrition » Parenteral nutrition/feeds. Nurses need to use a validated assessment Support, Enteral Tube Feeding and Parenteral tool to assess pressure ulcer risk before and Nutrition. www.nice.org.uk/CG32 National Patient Safety Agency (2011) Risk of Oral hygiene after surgery, and as the patient’s condi- Harm to Patients who are Nil by Mouth/Signal. Fasting can cause oral discomfort (Box 2) tion changes. Nutrition is important in tinyurl.com/NPSA-NBM and be an infection risk. Oral care is some- preventing pressure ulcers (NICE, 2014) Poulton TJ (2012) Gum chewing during pre- anesthetic fasting. Paediatric Anaesthesia; 22: 3, times neglected by nurses and not consid- and forms part of the risk assessment. 288-296. ered a priority (RCN, 2012; Bisset and Pre- Nurses must consider other factors that Roberts S (2013) Preoperative fasting: a clinical shaw, 2011). could increase the risk, such as: audit. Journal of Perioperative Practice; 23: 1/2, 11-16. Royal College of Nursing (2012) Safe Staffing for Some patients will have experienced » Length of operation; Older People’s Wards. RCN Summary Guidance oral problems before surgery due to treat- » Hypotension and low core temperature and Recommendations. tinyurl.com/RCN- ment or an existing problem, for example: during surgery; safestaffing-olderpeople » Xerostomia (dry mouth) is common in » Possible post-operative reduced Royal College of Nursing (2005) Peri-operative Fasting in Adults and Children. An Rcn Guideline older people and patients who have had mobility. for the Multidisciplinary Team. London: RCN. chemotherapy, causing soreness and an Patients must not fast for longer than Slater R (2010) Impact of an enhanced recovery unpleasant taste; necessary and, if they are at risk of devel- programme in colorectal surgery. British Journal of Nursing; 19: 17, 1091-1099. » Fear of surgery raises anxiety levels, oping pressure ulcers, pressure-redistrib- Varadhan KK et al (2010) Enhanced recovery after which can contribute to a decreased, uting mattresses should be used and surgery: The future of improving surgical care. thicker flow of saliva due to activity of patients’ position varied. Critical Care Clinics; 26: 3, 527-547.

14 Nursing Times 25.06.14 / Vol 110 No 26 / www.nursingtimes.net