NUTRITIONAL SUPPORT IN SURGICAL PATIENTS

M K ALAM MS ; FRCS

Professor of Surgery & Consultant Surgeon

ObjectivesThis presentation will explain:

•The need of nutritional support in surgical patients

•Consequences of malnutrition in surgical patients.

•Methods of assessing malnutrition

•Types of nutritional support, its indications

• Routes of providing nutritional support

•Complications of nutritional support.

ADEQUATE DIET IS NECESSARY TO MAINATAIN NORMAL BODY

COMPOSITION AND ORGAN FUNCTIONS

Aim of nutritional support• The provision of nutrients with therapeutic intent

(prevent or 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

• 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- 1600 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

POSTOP. STARVATION

↑ hormonal stimulation

↑ cellular activity

↑ metabolic rate

↑ energy expenditure

↑ gluconeogenesis

↑ protein breakdown

↑ nitrogen loss

↑Lipolysis

MAIN CONSIDERATIONS IN NUTRITIONAL SUPPORT

• Which patient requires nutritional support

• Select the appropriate substrate

• Obtain and maintain access for delivery

WHICH PATIENT?

• Severely malnourished

• 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 ( normal- 18.5-24.9)

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. 30-35 Kcal/kg/day

Energy source : Carbohydrates 60-70%

Lipids 20-30 %

Protein requirements in adults

Uncomplicated patients 1 g/ kg/ day

Complicated/ stressed pts. 1.3-1.5 g/ kg/ day

Calorie: nitrogen ratio - 150 : 1

Stress state- 100 : 1

Electrolytes:*

* adjusted on a daily basis

Sodium - 1 - 1.5 mEq / kg /day

Potassium 0.7 - 1 mEq/ kg/ day

Calcium 0.2-0.3 mEq/ kg/ day

Magnesium 0.35-0.45 mEq /kg /day

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

Gastrointestinal: Diarrhea, vomiting, pain

Pulmonary: Aspiration

Infection: Tube site

Total parenteral nutrition- TPN

Delivering predigested nutrients via hyperosmolarsolution 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,

Others: Cirrhosis, acalcular cholecystitis,

Gallstone, osteomalacia

Principle & Practice of Surgery

5th edition

Garden, Bradbury, Forsyth & Parks