Nutritional Care of the Bariatric Patient in Critical Care Christine Ward Bariatric Dietitian September 2011

Aim  To identify factors that may impact on the nutritional care of the bariatric patient group  Why this group may require a Critical Care admission?  What are the potential issues regarding feeding?  Which BMR estimation equation is most appropriate for the bariatric patient?

Factors that may impact on nutritional care of bariatric patients  Obese patients generally viewed as over nourished  Potentially deficient in a number of nutrients  Respond to injury differently; can not utilise/mobilise fat stores for energy as well as lean counterparts  Will draw on lean mass for energy  Considered that they may already metabolically stressed due to obesity  2 weeks Pre-operative dietary restriction ~1000kcal/day

The bariatric candidate over nourished or not? 5/20/20154 Vitamin/mineralERI % Ernst et al 2009 % Folate403.4 Folate & B Iron40n/a Zinc OH Vit D Vit D & Secondary hyperparathyroidism

Type of Surgery Laparoscopic Procedures  Restrictive Adjustable Gastric BandAdjustable Gastric Band Sleeve GastrectomySleeve Gastrectomy  Restrictive and Malabsorptive Roux-en-Y-Gastric BypassRoux-en-Y-Gastric Bypass Duodenal Switch /BPDDuodenal Switch /BPD

Critical care admission? Planned Critical CarePlanned Critical Care Clotting issues thrombolysis CPAP: patient not independent

Unplanned Bariatric patients in Critical Care Undiagnosed sleep apnoeaUndiagnosed sleep apnoea Prolonged ventilationProlonged ventilation Large bleeds - liverLarge bleeds - liver Conversion to open procedureConversion to open procedure Rhabdomyolysis, renal failure, sepsis, respiratory failureRhabdomyolysis, renal failure, sepsis, respiratory failure Anastomotic leak or strictureAnastomotic leak or stricture ERI: 5% patients (6-20% cited in many papers)

  Usual Protocol post surgery   Oral Route Immediately post bariatric surgery if gut intact Immediately post bariatric surgery if gut intact day 1; sips,day 1; sips, day 2; clear fluid,day 2; clear fluid, day 3; free fluidday 3; free fluid Use of nutritional supplements, high protein where appropriate Use of nutritional supplements, high protein where appropriate Feeding Route?

Enteral or Parenteral Nutrition ? NG, NJ, gastrostomy / jejunostomy ? NG, NJ, gastrostomy / jejunostomy Altered gastrointestinal anatomy/function Altered gastrointestinal anatomy/function Which feed?Which feed? TPN TPN How soon? How soon? ?Within 48 hours or ? NICE 2006?Within 48 hours or ? NICE 2006 Re-feeding issues K, Mg, PO, thiaminRe-feeding issues K, Mg, PO, thiamin Biochemistry monitoring (daily or as local protocol)Biochemistry monitoring (daily or as local protocol) Is it possible to meet nutritional requirements?Is it possible to meet nutritional requirements? Overfeeding vs. under feeding Overfeeding vs. under feeding

Risks from nutritional support for the obese patient  Overfeeding Increase C0 2, breathing and prolonged mechanical ventilation Increase C0 2, breathing and prolonged mechanical ventilation Promotes fat infiltration of liver (esp. CHO) Promotes fat infiltration of liver (esp. CHO) Cautious administration of CHO (dextrose) fat and fluid for obese with T2DM, Congestive heart failure, metabolic syndrome (exacerbation of conditions) Cautious administration of CHO (dextrose) fat and fluid for obese with T2DM, Congestive heart failure, metabolic syndrome (exacerbation of conditions)

Hypo energetic feeding and protein sparing  Improved glucose control  Improved serum iron binding and albumin  Appropriate energy deficit without increasing lean tissue catabolism can be achieved Dickerson et al 2004, Choban et al 2005, % of energy requirements and 2.1g protein /kg IBW resulted in N balance Dickerson et al 2004, Choban et al 2005, % of energy requirements and 2.1g protein /kg IBW resulted in N balance

Aim of nutritional support in critically ill patients?  Meeting measured energy requirements vs. preservation of lean body mass vs. risks of under or overfeeding

BMR Prediction Equations (Schofield)  Criticism of current PENG guidance Estimations equations based on healthy population Estimations equations based on healthy population Inappropriate use of stress factors; overestimates Inappropriate use of stress factors; overestimates Use of static variable such as weight, the body’s physiology ?temperature and respiration rate Use of static variable such as weight, the body’s physiology ?temperature and respiration rate Based on a linear relationship between weight and BMR Based on a linear relationship between weight and BMR

 However Findings from Horgan and Stubs 2003 re- examination of Schofield equation: Findings from Horgan and Stubs 2003 re- examination of Schofield equation: Small numbers of obese patients Small numbers of obese patients BMI>30 =4.5%BMI>30 =4.5% The linear relationship between BMR, weight, height and age only evident to a weight of ~ 70-75kgThe linear relationship between BMR, weight, height and age only evident to a weight of ~ 70-75kg

BMR Prediction Equations  Over estimates requirements for high BMI  Adipose tissue to lean tissue relationship 75:25  Main determinant of BMR is lean tissue  Obese have a higher absolute BMR due to a greater total mass of metabolically active tissue  BMR /Kg is lower due to the higher proportion of adipose tissue  BMR/Kg of fat free mass for most subjects is the same

Henry/Oxford Equations 2005  Based on studies from  10,552 BMR values  Rigorous evaluation of methodology  Advantages  Contains a more representative sample of the world population

SACN recommendations (draft) (  Use of Henry BMR equations Weight only Weight only Height and weight Height and weight Henry found no significant advantage in ht & wt equation Henry found no significant advantage in ht & wt equation  For predicting BMR using weight only (height difficult to obtain in clinical setting) (height difficult to obtain in clinical setting)  Launch later this year

Assessment prior to feeding As you would for other obese or lean individual As you would for other obese or lean individual Up to date weight crucialUp to date weight crucial Scales suitable for purpose, bed, hoist, stand on,Scales suitable for purpose, bed, hoist, stand on, Immediately pre-surgical for bariatric patients availableImmediately pre-surgical for bariatric patients available Reported weight or estimatedReported weight or estimated Knowledge of patient background,Knowledge of patient background, type of surgery,type of surgery, nutritional intake prior to surgery,nutritional intake prior to surgery, amount of weight loss/timeamount of weight loss/time Potential for nutritional deficienciesPotential for nutritional deficiencies

Calculating nutritional requirements? Energy requirements Non stressed Feed to BMR using actual body weight Feed to BMR using actual body weight with kcal for decrease in energy stores Mild to moderate stress: Calculate as normal Calculate as normal Omit stress and activity avoiding adverse effects of overfeeding Omit stress and activity avoiding adverse effects of overfeeding Severe stress Might be necessary to add a stress factor to BMR Might be necessary to add a stress factor to BMR

Obesity Double Check In order of decreasing accuracy / evidence Ireton Jones energy equations (critically ill but not ventilated) Adjusted average weight (PENG pocket guide 4 ) kcal/kg actual body weight (critically ill only) Glynn 1999, Alberda 2002

Protein Requirements 4  0.2g N/kg Actual body weight x 6.25  And where BMI >30 use 75% of the value estimated from actual weight BMI >30 use 75% of the value estimated from actual weight BMI> 50 use 65% of the value estimated from actual weight BMI> 50 use 65% of the value estimated from actual weight

Fluid Requirements 4  Very individual; ventilation,  The guidelines err on side of caution Fluid requirements not a linear relationship with weight, Fluid requirements not a linear relationship with weight, Avoid fluid overload Avoid fluid overload  Consider, is volume sensible? mls  Have losses been taken into account

Final thoughts  Estimated Energy requirements only starting point  Review and monitor patient regularly  Consider duration of nutritional support?  Are nutritional goals being met?  Requirements change: patients clinical condition, nutritional status, stress level, prognosis  Never blindly follow guidelines: clinical judgement required

References 1. American Society for Metabolic and Bariatric Surgery Guidelines Ernst B, Thurnheer M, Schmid S M, Schultes B. Evidence for the necessity to systematically assess micronutrient status prior to bariatric surgery. Obesity Surgery. 2009; 19: Flancbaum L, Belsley S, Drake V, et al. Preoperative nutritional status of patients undergoing Roux-en-Y gastric bypass for morbid obesity. J Gastrointest Surg. 2006;10(7): A Pocket Guide to Clinical Nutrition. 3 rd Edition. The Parenteral and Enteral Nutrition Group of the British Dietetic Association Cheatham ML, Safcsak K, Brezinski SJ, et al Nitrogen balance, protein loss and open abdomen. Crit Care Med. 2007;35: