CLINICAL
ORAL NUTRITIONAL SUPPLEMENTS: NUTRITION SUPPORT IN THE OBESE HOSPITAL INPATIENT Jessica Coates Acute Dietitian, Wirral University Hospital NHS Foundation Trust Jess works as an Acute Dietitian in a large district general hospital. She sees patients with a variety of needs, often focusing on nutrition support. Gastroenterology is becoming one of her main interests. @JessCoatesRD
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As obesity continues to become a growing problem in the UK and across the world,1 an increasing emphasis is being placed on all aspects of hospital treatment for this patient group. This article will look into the screening and assessment of nutritional risk, as well as use of oral nutritional supplements (ONS), in the obese hospital inpatient. As an Acute Dietitian, I am only too aware of the consequences of malnutrition. Increased risk of infection, poor wound healing and increased length of hospital stays are just a number of the negative effects experienced by patients. Rapid weight loss in hospitalised patients is associated with increased complications and poor outcomes, regardless of original body mass index (BMI).2 So, what happens when an obese patient is malnourished? Are they screened in the same way as a ‘frail’ patient? Are they offered the same assessment and treatment as their neighbour on the ward? NUTRITIONAL SCREENING
Current NICE guidelines state that all hospital inpatients should be screened for malnutrition on their admission and weekly thereafter.2 NICE also suggests that unintentional weight loss and period of reduced intake should be considered, using validated tools such as BAPEN’s Malnutrition Universal Screening Tool (MUST). In those with a BMI of >20kg/m2, malnutrition risk is heightened by: • unintentional weight loss greater than 10% within the last three to six months; • having eaten little or nothing for more than five days and/or are likely to eat little or nothing for the next five days or longer; • a poor absorptive capacity and/ or have high nutrient losses and/ or have increased nutritional needs from causes such as catabolism.2
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Early identification of this risk facilitates appropriate management to be instigated without delay and can avoid a patient’s nutritional status deteriorating further. The most recent data available from BAPEN’s Nutritional Screening Week project shows that 49% of patients with a MUST score of 2 or more (usually triggering referral to Dietetic departments), had a BMI of <20kg/m2.3 Could this be because those patients with a higher BMI are not being properly screened? We know that some healthcare professionals (HCPs) tasked with screening for malnutrition would prefer to use their own clinical judgement when assessing risk, rather than using valuable time to fully complete a screening tool.4 In a small study on a medical admission unit, it was found that many nurses were reluctant to weigh patients, feeling that it was ‘unnecessarily invasive’ and made them feel uncomfortable.5 This is despite the fact that research has shown high risk of malnutrition is a common finding in obese hospital inpatients, leading to similar negative outcomes to those patients who have a low BMI.6 Anecdotally, a further barrier can be lack of appropriate and available bariatric weighing equipment. Many hospital scales have a maximum weight of 200kg and some clinical areas can struggle to access chair, bed or hoist scales. Regardless that any hospital inpatient is at risk of protein wasting and muscle loss,7 obesity on admission
We know that rapid weight loss, intentional or unintentional, can be physically dangerous and psychologically damaging. The potential complications and amount of dietetic follow up required by those patients undergoing bariatric surgery emphasises this.
can cause recent weight loss to be missed. A patient might be less likely to highlight recent weight loss as a problem when in consultation with HCPs, due to society’s positive associations with obese people losing weight, whatever the method. Research has shown that obese people can experience stigma and prejudices in many aspects of their lives, including when accessing healthcare, sometimes leading to stereotypes of laziness and non-compliance with treatment.8 We know that rapid weight loss, intentional or unintentional, can be physically dangerous and psychologically damaging. The potential complications and amount of dietetic follow up required by those patients undergoing bariatric surgery emphasises this.9 Indeed, NICE only recommends very low calorie diets (<800kcals/ day) as part of a multicomponent weight management strategy, with extensive support and follow up, in order to restore a healthy, well-balanced diet in the long term.10 Current guidelines advise a steady weight loss of 0.5-1kg per week, brought about by reducing intake by 600-1000kcals, dependent on a patient’s current intake and response to treatment.11 This is because it has been indicated that the majority of people are more likely to sustain healthy lifestyle changes that are made in small steps, rather than radical diets that result in extreme weight loss in the short term.
Weight loss should never be a nutritional goal during an acute illness or hospital stay, whatever the patient’s weight on admission. Why then, is it sometimes seen as acceptable when an obese patient loses weight due to low appetite resulting from an acute illness? NUTRITIONAL REQUIREMENTS
If an assessment of nutritional risk is carried out, and a patient is referred to the dietitian, the next challenge is calculating nutritional requirements. It has been well-documented that standard, weight-based predictive equations are less accurate in those with a BMI of >25kg/m2.12 Indeed, ASPEN guidelines state that if indirect calorimetry and Penn State University equations cannot be used, energy requirements may be based on the Mifflin-St Jeor equation, using actual body weight.13 However, this is a weak recommendation, with only moderate evidence to support it in practice. Many dietitians in the UK choose to use the PENG recommendations to calculate nutritional requirements: using the Henry equation for energy, omitting stress and activity factors for those patients with a BMI of >30kg/m2 to avoid overfeeding.14 A disproportionate ratio of fat mass to fat free mass is seen in obesity, increasing the risk of overfeeding energy when calculating resting energy expenditure, using weightbased predictive equations. To calculate protein www.NHDmag.com April 2018 - Issue 133
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CLINICAL CASE STUDY Male, 55 years, background of T2DM and HTN, recently admitted due to influenza. Weight: 114kg, Height: 1.72m, BMI: 38.5kg/m2 ASPEN equation = wt (kg) x 14 = 114 x 14 = 1596kcals and 1.2g x wt (kg) = 1.2 x 114 = 136.8g protein per day PENG method = 14.2 x 114 + 593 = 2212kcals and (0.15-0.17) x 114 x 6.25 x 0.75 = 80-91g protein per day Mifflin St Jeor = 10 x weight (kg) + 6.25 x height (cm) â&#x20AC;&#x201C; 5 x age (y) + 5 = 10 x 114 + 6.25 x 1.72 - 5 x 55 + 5 = 871kcals per day These methods clearly give a wide range of potential calorie and protein goals. Anecdotally, it could be extremely difficult for a patient to meet the ASPEN requirements based on a hospital menu. Foods available which are high in protein tend to also be higher in calories. Most UK hospitals use the BDAâ&#x20AC;&#x2122;s Nutrition and Hydration Digest to provide targets for the calorie and protein capacity of their menus.16 This document suggests that the energy a hospital menu should provide (including all meals, snacks, puddings and drinks) would be a maximum of 2772kcals and 83g protein, to meet the needs of most patients. This would clearly make the ASPEN protein recommendation an impossible task, even if the patient had an excellent appetite. Therefore, it can be essential to involve a dietitian in order to consider additional nutrition. It is possible that ONS should focus on lower calorie, higher protein products in some obese patients. The availability of these products in many hospitals in the UK is variable, leading to further challenges of meeting estimated protein requirements, whilst aiming to avoid overfeeding calories.
requirements, PENG suggests using 75% of the value estimated using actual body weight, for those with a BMI of 30-50kg/m2. Needs may be higher, however, if patients have co-morbidities such as pressure damage or wounds, which can be more frequently seen in those with morbid obesity. The proposed new method to calculate these requirements for all adult patients is eagerly awaited by the dietetic profession, due in the next edition of the PENG Pocket Guide, available May/June 2018. WHAT SHOULD WE RECOMMEND?
Based on the difficulties in estimating requirements in this population group and the risks associated with overfeeding, an increasing body of evidence, particularly in intensive care, has become the topic of much debate. Research has suggested that hypocaloric, high protein feeding may achieve favourable outcomes.15 However, much research focuses on parenteral nutrition and a randomised controlled trial investigating hypocaloric, high protein feeding, compared to eucaloric feeding, has yet to be published. ASPEN published guidelines to be used with all obese hospitalised patients, stating that a hypocaloric regime of target calories of 50%-70% of estimated energy needs, or <14kcal/kg actual weight and protein of 1.2g/kg actual weight or 2-2.5g/kg ideal body weight, can be used in those patients who do not have severe renal 18
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or hepatic dysfunction.13 ASPEN also advises clinical vigilance to ensure adequate protein provision, as underfeeding is associated with unfavourable outcomes. Although recent research has supported these guidelines, they are based on poor evidence and give a weak recommendation. CONCLUSION
There is a paucity of evidence relating to ONS use in the obese hospital patient, in regards to usage, outcomes and opinions of HCPs. Extrapolating from previously mentioned research and personal professional experience, many medical and nursing staff appear to believe that prescribable nutrition is inappropriate for obese patients, regardless of their current intake. Dietitians are well placed to both add to the evidence base and to use available evidence and guidelines to challenge these views, potentially leading to improvements in patient care and outcomes for this patient group. Despite limited research in the area, the dietitian must use the best available guidelines and evidence to ensure that patients receive adequate calorie and protein intakes whilst in hospital, to minimise negative effects of underfeeding. This care plan would most likely be monitored using body weight, with the aim of the intervention being to maintain current weight. This may involve the provision of prescriptive ONS.