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

Nursing PracticeReviewNutrition

Keywords: Nutrition/Nil by mouth/ Fasting/Surgical care This article has been double-blind peer reviewed

Intravenous fluids may be required when patients exceed fasting times Al

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Author Catherine Liddle is senior lecturer at Birmingham City University.Abstract Liddle C (2014) Nil by mouth: best practice and patient education. Nursing Times; 110: 26, 12-14.Some patients need to stop eating and drinking, to be nil by mouth, at certain points in their care pathway for their own safety; their care will vary, depending on individual needs. Nurses need adequate knowledge of NBM guidelines to know how to implement them and be able to educate patients. This article explains how to care for patients who are NBM during pre- or post-operative periods.

Patients are restricted from eating and drinking, commonly known as being nil by mouth (NBM), as a result of a variety of conditions and at different times in their treatment pathway, particularly during surgery.

Conditions include non-functional bowel, acute abdomen, dysphagia, uncon-sciousness or reduced level of conscious-ness, and nausea or vomiting. The nursing care will vary for each, depending on the length of time the patient will be NBM and their individual circumstances. This article looks at caring for patients who are NBM before or after an operation.

When a patient fasts in hospital for a long time, problems may occur, typically: Dehydration; Malnutrition and electrolyte imbalance; Hypoglycaemia; Nausea and vomiting.

Older people, children, pregnant women and patients who are critically ill are particularly vulnerable (Chand and Dabbas, 2007). When patients become dehydrated, they display physiological

5 key points 1Patients who are to be nil by mouth need to be physically and psychologically prepared for the period of fasting

2All staff should have a good understanding of current fasting guidelines

3Communi-cation between staff and patients is essential

4A nil-by-mouth plan of care and associated assessments should be implemented, documented and updated

5Patient privacy, dignity, comfort and safety must be maintained at all times

signs including hypotension, tachycardia, oliguria, confusion and a decreased level of consciousness. This, together with the psy-chosocial factors of fasting being unable to eat or drink like other patients can make being NBM an unpleasant experience.

Preparing patients The multidisciplinary team should have a good knowledge and understanding of fasting guidelines so patients are given accurate information, relevant informa-tion is documented and local guidelines are followed (Lorch, 2007; Royal College of Nursing, 2005).

Before admission, patients need to be fully informed about fasting pre- and post-operatively to: Ensure adherence; Reduce the risk of surgery being

delayed/cancelled; Aid a smooth and rapid recovery.

Patients with a learning disability or cognitive impairment will need extra sup-port to ensure they understand the impor-tance and safety aspects of fasting. Patients who are prepared are less prone to experi-encing anxiety and more likely to have a reduced stress response to surgery (Var-adhan et al, 2010).

Pre-operative fasting For decades, patients have fasted from midnight or even longer for a morning the-atre list and from 6am if on the afternoon list (Brady et al, 2010). This practice has become ritualistic in clinical areas. The RCN (2005) published guidelines to change out-of-date and varied practice in the UK.

Evidence-based pre-operative fasting is a medical and legal requirement to maintain patient safety. Unless it is for emergency

In this article... Why patients should be nil by mouth before and after surgery Best practice and how to educate patients How to relieve patients discomfort when they are nil by mouth

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

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

surgery, patients should not be given an anaesthetic without a period of being NBM; this reduces the risk of pulmonary aspiration if gastric contents are regurgi-tated. The gag, swallow and cough reflexes usually protect the airway from aspiration of food or fluids but, when patients are anaesthetised, these are suppressed to varying degrees (Brady et al, 2010).

Brady et als (2010) review of randomised controlled trials suggested that patients who drank clear fluids up to a few hours before surgery were at no greater risk of aspiration than in those who fasted from midnight; those who fasted for the shorter period also had a lower gastric volume.

The RCNs (2005) guideline states that prolonged fasting can increase the risk of aspiration of stomach contents, leading to respiratory problems and possibly death.

Obesity, pregnancy, peptic ulcer, gastric reflux, stress and pain place patients at a higher risk of aspirating (Brady, 2010; RCN, 2005). A surgeon or anaesthetist may request a longer fasting time for these patients (RCN, 2005).

Jones and Swarts (2013) Guidelines for the Provision of Anaesthetic Services recommends patients with diabetes are fasted for the minimum amount of time, as fasting, sur-gical stress and inactivity can all have a neg-ative effect on blood-sugar control, and are placed at the top of the operating list.

A safety alert (National Patient Safety Agency, 2011) reported the risk of harm to patients who are kept unintentionally NBM for prolonged periods. This was prompted by the case of a patient kept NBM for 10 days awaiting a procedure. The alert underlines the fact that vulnerability, dehydration, malnutrition or complica-tions from omitted or delayed medication are intensified when a patient is exposed to long periods of being NBM. It concludes by recommending that organisations: Assess for alternative methods of

hydration, nutrition and medication; Document a NBM care plan; Communicate the patients NBM status

to all relevant staff.Patients should be reviewed individu-

ally by nursing and medical staff to ensure their NBM time is kept to a minimum. Nurses are pivotal in ensuring communi-cation is maintained between theatre and ward staff and the patient.

The RCN (2005) published recommen-dations for pre-operative fasting for healthy adults (Box 1). These advise that sweets are classed as food and chewing gum should be avoided on the day of sur-gery; however, Poulton (2012) states there is evidence that gum chewing promotes

gastrointestinal motility and physiologic gastric emptying.

When surgery is delayed, the guidelines recommend the surgical team consider allowing adults some water to prevent dehydration and relieve thirst; they do not, however, stipulate how much water can be drunk. Staff should consider giving chil-dren a drink of water or another clear fluid; if the delay is to be longer than two hours, one should definitely be given (RCN, 2005).

Roberts (2013) literature search revealed that, despite best-practice guidelines, pre-operative fasting times remain excessive. He recommended more detailed patient literature, including the implications of extending fasting times and the possibility of associated nausea and headaches.

Lorch (2007) undertook an action research study to improve the patient expe-rience and implement the RCNs (2005) guidelines. The outcome improved patient and staff knowledge, improved patient comfort and safety, ensured uniformity of practice, improved communication between patients and staff, and avoided the omission of prescribed medication.

Pre-operative medicationPrescribed regular oral medication and pre-medication, unless contraindicated and excepting oral hypoglycaemic medicines, should be administered pre-operatively to avoid surgery being cancelled, for example due to hypertension (Lorch, 2007; RCN, 2005). Adults can have up to 30ml of water and children up to 0.5ml/kg (up to 30ml) to take the medication (RCN, 2005).

Risk assessmentPre-operatively, a malnutrition risk assess-ment should be performed, which should

consider how long the patient will be fasting before, during and after surgery. National Institute of Health and Care Excellence (2006) guidance recommends using a validated screening tool (such as the Malnutrition Universal Screening Tool). Screening should include: Assessment of body mass index; Unintentional weight loss; Time of unintentional reduced

nutritional intake or future impaired nutrient intake. This is important to prevent surgery

being cancelled due to malnutrition and related post-operative complications.

Patients who have post-operative nausea, vomiting or a non-functioning gut due to gastrointestinal surgery can remain NBM for longer; in some cases, nutritional support may be required.

NICE (2006) guidance provides flow-charts on when to consider oral, enteral and parenteral nutritional support pre-operatively. A few surgical patients will have artificial feeding pre-operatively those with severe weight loss, very low body mass index or a risk of post-operative complications (Braga et al, 2009). Paren-teral nutrition will be considered for patients who are malnourished and have an inadequate or unsafe enteral intake or a non-functional inaccessible or perfo-rated gastrointestinal tract (NICE, 2006).

Post-operative care Fasting Patients with a short fasting time are less likely to experience post-operative nausea and vomiting and are more likely to have a quicker and more comfortable post-opera-tive recovery and experience (Chand and Dabbas, 2007).

RCN (2005) guidelines state that as long as there are no contraindications, patients can be offered and encouraged to drink fluids post-operatively. They say it may be better for children to try breast milk or clear fluids first. This does not apply to patients who have had gastrointestinal or major abdominal surgery.

Enhanced recovery programme The NHS Institute for Innovation and Improvements enhanced recovery pro-gramme, launched in 2008, has been used in many specialties. It aims to minimise the bodys stress response to anaesthesia and surgery, reducing post-operative recovery time so patients can be discharged earlier (Foss and Bernard, 2012; Slater, 2010).

Key aspects are managing fluid balance and fasting times, and ensuring patients do not become malnourished or dehydrated.

Box 1. Nil By mouTH: guidANCe

Patients can take the following before being anaesthetised:

AdultWater up to two hours beforeFood up to six hours before

ChildWater and clear fluids up to two hours beforeBreast milk up to four hours beforeFormula/cows milk or solids up to six hours before

Source: Royal College of Nursing (2005)

Ensure patients are at the centre of your thinkingTracy Mannix p28

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

Patients are given a clear, carbohydrate-rich drink before midnight and a second drink 2-3 hours before surgery to reduce their discomfort from fasting and pre-operative thirst and hunger (Brady et al, 2010). The evidence suggests that carbohy-drate drinks pre-operatively result in a shorter stay in hospital due to a quicker return of bowel function, a reduced loss of body mass and a decrease in post-operative nausea and vomiting (Jones et al, 2011).

Fluids and diet are often reintroduced on the day of surgery to promote gut motility and reduce the risk of the patient developing an ileus (when peristalsis stops and the bowel ceases to function) (Var-adhan et al, 2010).

Intravenous therapy Nurses need to know when patients exceed their fasting time and discuss introducing intravenous fluids with doctors. BAPEN (2011) offers recommendations on pre-, intra- and post-operative fluid manage-ment in adult surgical patients. Mechan-ical bowel preparation is avoided where possible but, if it is necessary, it is common for an electrolyte imbalance and dehydra-tion to occur; this should be corrected with IV fluid and closely monitored (BAPEN, 2011; National Confidential Enquiry into Patient Outcome and Death, 2011).

Nursing care should include mainte-nance of an accurate fluid balance chart; cannula care should include the use of a phlebitis scale to prompt action.

Fluid balance Patients receiving additional fluid or nutritional support should have their fluid balance recorded on a fluid balance chart so it can be assessed. This should include: Urine output (minimum of 0.5ml/kg/hr); Any other output; All IV fluids; Parenteral nutrition/feeds.

Oral hygiene Fasting can cause oral discomfort (Box 2) and be an infection risk. Oral care is some-times neglected by nurses and not consid-ered a priority (RCN, 2012; Bisset and Pre-shaw, 2011).

Some patients will have experienced oral problems before surgery due to treat-ment or an existing problem, for example: Xerostomia (dry mouth) is common in

older people and patients who have had chemotherapy, causing soreness and an unpleasant taste;

Fear of surgery raises anxiety levels, which can contribute to a decreased, thicker flow of saliva due to activity of

the sympathetic nervous system. In dehydrated patients, saliva secretion

stops to conserve water (Jenkins et al, 2010). Post-operatively, patients may remain

NBM for several hours or longer and be prone to xerostomia due to dehydration, oxygen therapy and side-effects of the anaesthetic. They will need frequent oral care (Bisset and Preshaw, 2011).

Mouthwash should be available for patients; they may prefer to use their own but those that contain alcohol can have a drying effect on the mouth. Chlorhexidine mouthwashes can reduce the level of plaque and bacteria but should not be used more than twice a day because of their alcohol content. Dingwall (2010) suggests using 0.9% saline as this does not affect the pH of saliva and is flavourless. Lemon and glyc-erine swabs are discouraged the lemons acidity damages tooth enamel and glycerine draws fluid away from the tissues, reducing saliva production. Glycerol or petroleum jelly can be applied to the lips but can feel sticky; patients own lip balm or a water-soluble gel can be used (Dingwall, 2010).

Patients who wear dentures may prefer to keep them in for as long as possible, sometimes until induction of the anaes-thesia; however, a dry mouth can make wearing them uncomfortable.

Pressure ulcers Nurses need to use a validated assessment tool to assess pressure ulcer risk before and after surgery, and as the patients condi-tion changes. Nutrition is important in preventing pressure ulcers (NICE, 2014) and forms part of the risk assessment. Nurses must consider other factors that could increase the risk, such as: Length of operation; Hypotension and low core temperature

during surgery; Possible post-operative reduced

mobility. Patients must not fast for longer than

necessary and, if they are at risk of devel-oping pressure ulcers, pressure-redistrib-uting mattresses should be used and patients position varied.

ConclusionEducational and clinical institutions must work together to educate all healthcare workers so patients have the best possible care when they are NBM. Surgeons, nurses, theatre staff, students and housekeeping staff need to follow the most recent guide-lines. Patients must be educated and kept informed about their NBM status. The RCN (2005) guidelines inform practice; local policies should reflect them. NT

ReferencesBAPEN (2011) British Consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients. tinyurl.com/GIFTASUP-IV-FluidTherapyBisset S, Preshaw P (2011) Guide to providing mouth care for older people. Nursing Older People; 23: 10, 14-21. Brady MC et al (2010) Preoperative fasting for adults to prevent perioperative complications. Cochrane Database of Systematic Reviews; 4: CD004423.Braga M et al (2009) ESPN guidelines on parenteral nutrition: surgery. Clinical Nutrition; 28, 378-386.Chand M, Dabbas N (2007) Nil by mouth: a misleading statement. Journal of Perioperative Practice; 17: 8, 366-371.Dingwall L (2010) Essential Clinical Skills for Nurses. London: Wiley Blackwell.Foss M, Bernard H (2012) Enhanced recovery after surgery: implications for nurses.British Journal of Nursing;21: 4, 221-223.Jenkins et al (2010) Anatomy and Physiology from Science to Life. New Jersey: Wiley,Jones C et al (2011) The role of carbohydrate drinks in pre-operative nutrition for elective colorectal surgery. Annals of the Royal College of Surgeons of England; 93:7, 504507. Jones K, Swart M (2013) Anaesthetic services for pre-operative assessment and preparation. In: Royal College of Anaesthetists Guidelines for the Provision of Anaesthetic Services. www.rcoa.ac.uk/system/files/GPAS-2013-FULL_0.pdfLorch A (2007) Implementation of fasting guidelines through nursing leadership. Nursing Times; 103: 18; 30-31.National Confidential Enquiry into Patient Outcome and Death (2011) Knowing the Risks. A Review of the Peri-Operative Care of Surgical Patients. NCEPOD. tinyurl.com/NCEPOD-2011National Institute for Health and Care Excellence (2014) The Management of Pressure Ulcers in Primary and Secondary Care. www.nice.org.uk/cg179National Institute for Health and Care Excellence (2006) Nutrition Support in Adults. Oral Nutrition Support, Enteral Tube Feeding and Parenteral Nutrition. www.nice.org.uk/CG32National Patient Safety Agency (2011) Risk of Harm to Patients who are Nil by Mouth/Signal. tinyurl.com/NPSA-NBMPoulton TJ (2012) Gum chewing during pre-anesthetic fasting. Paediatric Anaesthesia; 22: 3, 288-296.Roberts S (2013) Preoperative fasting: a clinical audit. Journal of Perioperative Practice; 23: 1/2, 11-16.Royal College of Nursing (2012) Safe Staffing for Older Peoples Wards. RCN Summary Guidance and Recommendations. tinyurl.com/RCN-safestaffing-olderpeople Royal College of Nursing (2005) Peri-operative Fasting in Adults and Children. An RCN Guideline for the Multidisciplinary Team. London: RCN.Slater R (2010) Impact of an enhanced recovery programme in colorectal surgery. British Journal of Nursing; 19: 17, 1091-1099.Varadhan KK et al (2010) Enhanced recovery after surgery: The future of improving surgical care. Critical Care Clinics; 26: 3, 527-547.

Nursing PracticeReview

Box 2. orAl effeCTs of BeiNg Nil By mouTH

Dry mouth, throat and tongueDifficulty in speakingSaliva that feels thick and stringyBad breathTeeth that feel coated and uncleanDry, cracked lips