NUTRITIONAL SUPPORT IN SURGICAL PATIENTS M K ALAM MS ; FRCS Professor of Surgery

Objectives This presentation will explain: The need for nutritional support Consequences of malnutrition Methods of assessing malnutrition Types of nutritional support & its indications Routes of providing nutritional support Complications

ADEQUATE DIET IS NECESSARY TO MAINATAIN NORMAL BODY COMPOSITION AND ORGAN FUNCTIONS

Definition Nutritional support is adjuvant therapy used to support the surgical patients until they are able to sustain themselves with adequate spontaneous nutrition by mouth.

Malnutrition in hospitalized patients is common Up to 50% may have moderate malnutrition Malnutrition increases morbidity and mortality Damaging effects on psychological status, activity level and appearance Prolongs hospital stay

ENDOGENOUS ENERGY STORES CARBOHYDRATE - GLYCOGEN Just enough to last one day Liver- 400 kcal Muscle kcal -- not readily available Essential for RBC, WBC, bone marrow, eye, renal medulla & peripheral nerves Brain- normally uses glucose, switches to fat in starvation 1 Gm. = 4 kcal

ENDOGENOUS ENERGY STORES FAT- ADIPOSE TISSUE Largest fuel reserve 120,000 kcal in a 70-kg man 1 Gm. = 9kcal Survival during starvation depends upon the amount of endogenous fat reserve

ENDOGENOUS ENERGY STORES PROTEIN Lean body mass- 13 Kg in a 70 Kg man 30,000 kcal energy store Inefficient source of energy Used for essential nitrogenous substances for maintenance and growth Synthesis requires non protein calorie source

SIMPLE STARVATION ↓ energy expenditure ↑ use of fat for fuel ↑ lipolysis ↓ nitrogen loss ↓ glucose use by brain* * RBC, WBC, renal medulla, neurons, muscles & intestinal mucosa supply maintained POST-SURGERY STARVATION ↑ hormonal stimulation ↑ cellular activity ↑ metabolic rate ↑ energy expenditure ↑ gluconeogenesis ↑ protein breakdown ↑ nitrogen loss ↑Lipolysis

Aim of nutritional support measures The provision of nutrients with therapeutic intent (prevent / reverse the catabolic effects of disease or injury). Identify in a timely manner patients in need of nutritional support Provide nutritional requirements by most appropriate route to minimise complications

MAIN CONSIDERATIONS IN NUTRITIONAL SUPPORT Which patient requires nutritional support Select the appropriate substrate Obtain and maintain access for delivery

WHICH PATIENT? Severely malnourished due to disease Become malnourished due to surgical therapy  Insufficient intake for more than 5-7 days  Unable to resume dietary intake within 5-7 days

ASSESSMENT OF NUTRITIONAL STATUS History : Altered oral intake Unintentional weight loss ( 10-15% in 4-6 months) Physical examination: Body weight / BMI = wt. in kg/ height in m² ( normal ) Mid arm muscle circumference <60% ( M 25.5 cm, F 23 cm ) Triceps skin fold <60% ( M 12.5mm, F 16.5mm )

ASSESSMENT OF NUTRITIONAL STATUS  Laboratory evaluation: Complete blood count Lymphocyte count < 1800/cmm Serum albumin < 30G/L  Immune competence: Delayed cutaneous hypersensitivity to intra-dermal antigens  Functional evaluation: Ability to do daily functions, hand grip

PREOPERATIVE NUTRITIONAL SUPPORT  Improves outcome in severely malnourished  If possible, delay surgery  5-7 days nutritional support  Avoid tumor feeding: limit calorie & protein to match need  Continue nutritional support postoperatively

ASSESSMENT OF NUTRITIONAL REQUIREMENTS Optimal nutrition should provide adequate requirements of : Calories- Carbohydrate & fat Protein Water Electrolytes Trace elements Vitamins

Energy requirements in adults  Energy : Uncomplicated patients- 25 Kcal/ kg/ day Complicated/ stressed pts Kcal/kg/day  Energy source : Carbohydrates % Lipids 20 %

Carbohydrates: Predominant form used- dextrose Optimal 4-5mg/kg/min. Lipids: 20% of total calories Lipid emulsion mixed with other element “3 in 1”

Protein  Uncomplicated patients 1 g / kg/ day  Complicated/ stressed pts g / kg/ day

 Electrolytes:* Sodium mEq / kg /day Potassium mEq/ kg/ day Calcium mEq/ kg/ day Magnesium mEq /kg /day * adjusted daily  Trace elements  Vitamins

Fluid requirements  100 ml/kg/day – first 10 kg body wt. 50 ml / kg /day- for next 10 kg 20 ml / kg /day- for each additional kg  1 ml of water / cal. / day  Adjust in patients : - who cannot tolerate large volume - additional fluid loss - febrile or septic

ROUTES USED FOR NUTRITIONAL SUPPORT Enteral nutrition: Providing liquid formula diet in to a functioning GIT to maintain or improve nutritional status Parenteral nutrition: Delivering predigested nutrients directly to venous system Mixed ( enteral + parenteral ): Tolerate low amount of enteral, weaning from parenteral

Routes of enteral feeding  Nasogastric tube feeding – for short periods  Fine bore nasoenteric tube- positioned in stomach, duodenum, jejunum, better tolerated  Gastrostomy/ jejunostomy– surgical/ endoscopic / radiologic, neurological diseases, head/ neck carcinoma, major upper GIT surgery

Enteral feeding  Intermittent bolus- suitable for stomach feeding  Continuous - suitable for duodenum/ jejunum feeding  Initiate at a slow rate, advance as tolerated  Initially dilute feeds, gradually advance to full strength  Feeding in semi-upright position particularly for stomach feeds  Maintain this position for 2 hours after feeds  Aspirate (stomach feeding) before next feeding. If >150ml, delay next feed.

Advantages of enteral feeding  Simplicity  Greater availability  Lower cost  Well tolerated  Maintains gut integrity  Fewer complications

Contraindications to enteral feeding  Intestinal obstruction  Paralytic ileus  High output entero-cutaneous fistula  Short bowel syndrome  Severe acute pancreatitis  Malabsorption

Complications of enteral feeding  Mechanical: tracheobronchial intubation, erosion blockage, displacement, bowel perforation  Metabolic: Fluid/ electrolyte imbalance, hyperglycemia Refeeding / overfeeding syndromes  Gastrointestinal: Diarrhea, vomiting, pain  Pulmonary: Aspiration  Infection: Tube site

Total parenteral nutrition- TPN Delivering predigested nutrients via hyperosmolar solution into venous system  CVN ( central venous nutrition ) : Subclavian / Internal jugular, Catheter tip in SVC Most commonly used  PVN ( peripheral venous nutrition ): Solution of lower calorie, lower dextrose and higher lipid Suitable for 7-10 days feeding

TPN - Indications  Non-functioning GIT Short bowel syndrome Intestinal fistula Severe pancreatitis Intractable vomiting/ diarrhea Severe inflammatory bowel disease Developmental anomalies Multiple organ failure  Sever malnutrition ( unable to take orally )

TPN - Administration  Check all laboratory values before starting  Nutrients given as 3in1 or 2+1  Vitamin k given separately  Heparin & insulin can be added  Start with 1 L, increasing to desired level as tolerated  Monitor- CBC, electrolytes, glucose, urea, creatinine, Ca., Mg., phosphorus, bilirubin, coagulation profile, ALP, ALT,AST  Best managed by nutritional support team

Home TPN  Long term nutritional support  Majority have malignancy  Special catheter- e.g. Hickman  Subclavian vein through subcutaneous tunnel  Support system

Complications of TPN Catheter related: Vessel injury, thrombosis, Haemo/ pneumothorax, Brachial plexus injury, air embolism, sepsis Metabolic: Hyperglycemia, hypoglycemia, Hypertriglyceridemia, fluid & electrolyte disturbance, Hyperosmolar syndrome, steatohepatitis, Refeeding and overfeeding syndromes Others: Cirrhosis, acalcular cholecystitis, Gallstone, osteomalacia

Principle & Practice of Surgery 5 th edition Garden, Bradbury, Forsyth & Parks