Introduction
Preoperative fasting is an experience which each individual must endure before entering the operating theatre. Fasting is an essential step. The purpose of fasting is to empty the stomach to reduce the risk of aspiration (Hamlin et al, 2009). Even though I am just a first year student with very little experience, I have already seen some conflicting recommendations regarding this subject. While working in the ward, nurses encouraged preoperative fasting to start at midnight which was different to what we learnt in our lectures, in which a preoperative fast of 4-6hrs was recommended.
Guidelines for Preoperative Fasting.
In 1999, the American Society of Anaesthesiologists (ASA) implemented preoperative fasting guidelines to help develop a high standard of patient care. These Guidelines propose that healthy patients have to fast six hours from solids and two hours from liquids. The current outstanding guidelines for elective patients and their Minimum fasting period in hours are: Clear liquids 2 hours, Breast milk 4 hours, Infant formula 6 hours, Non-human milk 6 hours, light meal 6 hours and regular meals 8 hours ( Blanchard, 2012). Even though these guidelines are in place, many studies have shown that hospitals are still using “NPO after midnight” without taking into consideration a patients characteristics, the procedure they are getting done or even the time the procedure is taking place. The guidelines for preoperative fasting in elective patients do not apply in acute situations. Following trauma or other surgical emergencies, fasting will not completely ensure that the stomach is empty. In emergency’s, the last time the patient ate or drank up to the trauma or start of pain should be recorded to outline the likelihood of a full stomach (Petring and Blake, 1993). A study that I read found that patients can fast for as long as 14 hours from solids and 12 hours from fluids. In some studies patients have fasted for a severe 37 hours from solids and 20 hours for fluids. Prolonged fasting can affect patient’s physical and psychological well-being.
Risk Assessment on pre-operative patients
On assessment some people may be considered to more likely regurgitate while under anaesthetic such as pregnant women, obese patients or patients with abdominal disorders etc. Patients who are also very ill or have been involved in an accident such as a car accident and they need surgery, they will be treated as they have a full stomach. An anaesthetist makes the risk assessment who would have been fully informed by the preoperative nurse of what the patients has recently eaten and drank (Hamlin et al, 2009).
The barriers to best practice
Prolonged preoperative fasting can be damaging to patients. Guidelines have changed over time from "nil by mouth from midnight”, to now where you only have to fast for two hours minimum form oral fluids. Nurses are expected to carry out these guidelines accordingly (Scott and Marfell-Jones, 2004). So why are patients fasting for prolonged periods of time? One reason I found is that nurses tend not to keep up with current literature in nursing. This could be due to the absence of time and motivation and also the lack of access to articles (Woodhouse, 2006) A great deal of research has taken place on safe preoperative fasting times, but still the majority of nurses are not mindful of the fact that lengthening the period of the fast does not improve patient safety and that the longer patients go without food and fluids, the greater the risk. British researcher Alun Woodhouse, suggested a possible barrier that would shorten fasting -times is to try and fix the power imbalance between nurses and doctors (Woodhouse, 2006). The nurses that took part in his study were said to have felt anxious and tense when they had to question doctors regarding preoperative fasting.
Managing acute patients
Organising patients for acute surgery can be challenging for nurses who attempt to lessen the period of the time patients are fasting for when possible. Acute patients going for surgery usually fast for a considerable amount of time longer than those on elective lists. Therefore they are at a greater risk of complications. There are many reasons for prolonged fasting such as lack of communication between theatre staff and ward staff, changes in theatre lists and capacity for acute surgery. In Letterkenny General Hospital there are Clinical Nursing Mangers (CNM) in each ward. In Surgical wards they are responsible for overseeing all the patients that are going to theatre, where they will go after theatre, and planning when and where acute surgery gets performed.
Adverse effects of fasting
There are many physical effects of extreme fasting for clients can include hypoglycaemia, electrolyte imbalance, poor wound healing, increased risk of developing pressure sores and a depressed immune system (Bothamley and Mardell, 2005). In the British Journal of Nursing there was a review that stated "poor preoperative nutritional status adversely affects wound healing" (Anderson, 2005). This highlights the importance of the role nurses have in improving nutritional status but also the need for collaboration with other members of the multi-disciplinary team, such as dieticians.
Diabetic Patients
Diabetic patients who have been fasting preoperatively have to be monitored closely to ensure that their glucose levels remain stable before they go to theatre. The aims when managing diabetics are to have stable perioperative glucose control, to promote wound healing and the reduction of infection, to prevent ketosis and hypokalaemia and to ensure they can cope with the postoperative vomiting (Hamlin et al, 2009).
The Positive contribution of nurses
The nurse that is in charge should have the skill to assess the risks of fasting on each individual patient. They should then be able to back up their decision if needs be in case of a delay etc. Maintaining communication between the nurses in the surgical wards and in theatre can be challenging. The operating theatre department is an isolated area compared to the rest of the hospital, and because of this it can lead to miscommunication and lact of understandting. (Bull and Fitzgerald, 2004). The writer noticed that departments are quick to blame each other when miscommunication occurs, or when an important part of patient care is neglected. This tension may be a result of the many demands on the time of all nurses. Evidently, the way to reduce the occurrence of dehydration is to provide fluids. If the nurse in charge is aware that their patient may need to fast for a prolonged period of times maybe even days then they should assess the patient and take into consideration that, that patient is more likely to become dehydrated and that they will need to arrange for intravenous (IV) fluids to be started. However this can sometimes requires a significant amount of time. The skill levels of the nurses available in the ward may not allow them to cannulise a patient for IV fluids and the availability of medical staff to chart the IV fluids can also affect the period of time patients are waiting for fluids. (Sigurdsson, 2001).

Enhanced-recovery-after-surgery programmes
The enhanced-recovery-after-surgery (ERAS) programme is an evidence-based treatment protocol for the entire perioperative care period for patients undergoing elective colorectal surgery. The key principles of the ERAS protocol include pre-operative counselling, preoperative nutrition, avoiding perioperative fasting and carbohydrates up to 2 hours preoperatively and early mobilization. The introduction of ERAS in a centre in the United Kingdom lead to a significant reduction in hospital stay and illnesses in patients, compared to traditional approaches (Weimann et al, 2005).
Conclusion
Overall preoperative fasting is an essential experience which everybody had to go through before entering the operating theatre. Fasting can be a tough experience but it is an essential step as it prevents aspiration. There are many reasons why preoperative patients fast longer than necessary. It is clear prolonged fasting negatively impacts on patients' health and well-being but nurses try and prevent this as best they can.

References

1) Anderson, B. (2005). Nutrition and wound healing: the necessity of assessment. British Journal of Nursing; 14: 19, 30-38.
2) Blanchard, J.C., (2012). Requirements for preoperative fasting. AORN J. 95(5), 661-664.

3) Bothamley, J. & Mardell A. (2005). Preoperative fasting revisited. British Journal of Perioperative Nursing. 15(9), 370-374.
4) Bull, R. M. & Fitzgerald. (2004). The invisible nurse: behind the scenes in an Australian OR. AORN Journal. 79(4), 810-823.
5) Hamlin, L., Davies, M. and Richardson-Tench, M. (2009). Perioperative nursing. Chatswood, N.S.W.: Elsevier Australia. (1) 24-32.
6) O.U. Petring, D.W. Blake. (1993). Gastric emptying in adults: an overview related to anaesthesia. Anaesthesia and Intensive Care. 21 (6), 774-781.
7) Scott, W. & Marfell-Jones, M. (2004). Evidence atone is not enough to bring about practice change. Koi Tioki Nursing New Zealand; 10(1), 14-16.
8) Sigurdsson, H. (2001). The meaning of being a perioperative nurse. AORN Journal; 74(2), 202-217.
9) Weimann A, Braga M, Harsanyi L, et al. (2005). ESPEN Guidelines on Enteral Nutrition: Surgery including organ transplantation. Clin Nutr. 25 (2), 224–244.
10) Woodhouse, A. (2006) Pre-operative fasting for elective surgical patients. Nursing Standard; 20(21), 41-48.

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