Nutrition on wound healing

Role ofNUTRITION IN WOUND HEALING

DR.Y.Prabhakara Rao M.S.,M.Ch

Nutrition is process by which a living organism assimilates food & use it for growth, metabolism & replacement of tissues.Adequate amounts of nutrients are needed for synthesis of nucleic acids i.e. RNA & DNAEven brief period of malnutrition will have negative effect on wound healingSo nutrition plays an essential role in wound healing & the goal of surgeon is to recognize when nutrition support is necessary

Surgery , trauma, sepsis causes protein catabolic stateIncreased energy expenditure above the basal needs is about10 % for elective surgery10-30% for trauma50-80% for sepsis100-200% for burns

Stages of Wound HealingNutrition plays a vital role throughout all stages of wound healingInflammatory Phase 2-5 daysProliferative Phase 2 days 3 weeksRemodelling or Maturation Phase 3 weeks 2years

Wound HealingA complex integrated sequence of cellular, physiologic, and biochemical events initiated by the stimulus of injury to tissue.The same events, in the same order, occur in every healing process regardless of the tissue type or the inciting injury.

Healing processThe activation of basic cellular processes of inflammation, cell proliferation, and growth as well as regulation of these processes until repair is complete.All repair occurs with an overlapping series of orchestrated events to limit the damage and restore the function and integrity of the structure.

TISSUE RESPONSES TO INJURYVascular events transient vasoconstriction, active vasodilatation, permeability change.Cellular events platelets, neutophils, macrophages, lymphocytes, fibroblasts, endothelial cells.Chemical mediators vasoactive agents, chemotactic factors, cytokines

PlateletsHemostasisRelease of platelet granules alpha - granules dense granules lysosomes

NeutrophilsProtection against infectionIntracellular products release free radicals cyclooxygenase products lipooxygenase products protease, antiprotease band2 protein

Macrophagesphagocytosisinitiation of fibroplasiarelease cellular products neutral protease, complement factors, reactive oxygen metabolites, growth factors, fibronectin, interleukin 1, enzyme inhibitors

Cytokines in wound healingTGF-PDGFFGFEGFIGF-1Etc. KGF, CTGF, TNF, interleukins

D = DiabetesI = InfectionD = DrugsN = NutritionT = Tissue necrosisH = HypoxiaE = Excessive tensionA = Another woundL = Low temperatureNon-healing DIDNT HEAL

Nutrition in wound healingDelayed or impaired wound healing may occur if nutritional status is inadequate

A nutritionally complete diet provides the optimum environment for recovery and healingwounds heal fasterstrengthens immune systemprevents development of further wounds e.g. Pressure wounds

Malnutrition results in:

Increased susceptibility to infectionPoor wound healing (including anastomotic breakdown/leakage, poor graft adherence etc)Increased frequency of decubitus ulcersBacterial overgrowth in the bowelAbnormal nutrient losses in the stool

Pre-op Nutritional Assessment

Pre-op nutritional assessment is a key element of the surgical history in non-emergent surgery; however, there is no one single, simple and reliable technique for assessing nutritional statusOn history, ask about chronic medical or comorbid conditions (DM, IBD, CV disease,etc), recent hospitalizations or current hospitalization, past surgery (esp GI surgery) that may contribute to malnourishmentVitamin or mineral useWt loss or gain, diet history

Physical Exam

Head and Neck: hair loss, bitemporal wasting, conjunctival pallor, xerosis, glossitis, bleeding/sore gums, angular cheliosis, stomatitis, poor dentition, thyromegalyExtremities: edema, muscle wasting, loss of sq fatNeurologic: evidence of peripheral neuropathy, reflexes, tetany, decreased mental statusSkin: ecchymosis, petechie, pallor, pressure ulcers, wound problems/infection

Anthropometric measurements

It is the science of assessing body size, weight & proportions.BMI: body mass index (weight(kg)/height(m) squared) BMI10% over 6 months signifies mod-severe malnutrition

Nutritional indicesCreatinine height index (CHI)Prognostic nutrition index (PNI)Nutrition risk index (NRI)Malnutritional universal screening tool (MUST)Weight statusUnintentional weight lossAcute disease effect

Nutrition RequirementsPre operativePost operative

Calories: 25-35 kcals/kg

Protein: 0.8-1 gm/kg

Fluids: 30 mls/kg

Calories: Increase to 30-40 kcals/kgProtein:Increase to 1-1.8 grams/kgFluids: Individualized

KEY NUTRIENTS IN WOUND HEALING

MacronutrientsMain sources of energy are:CarbohydratesFatProteinAdequate energy intake is required to prevent muscle loss, protein deficiency and unintentional weight lossEnergy requirements are higher for patients with wounds (up to 45% higher)

CarbohydrateConstitute 55-60% of the dietSource of cellular energy 3.4 Kcal/gmGlucose Glycogen

Brain , RBC & WBC depend only on glucose

Caution in diabetics, insulin > 250 mg/dl

Dietary sources: wholegrain breads & cereals, fruits, starchy vegetables, rice, pasta & dairy foods

Fat

Constitute 20-25% of the dietSafe & concentrated source of energy 9 Kcal/gmKey role in structure and function of cell membranesOmega 3s inflammation reductionTransports fat soluble vitamins.InsulationPadding over bony prominenceDietary sources: meat, nuts & seeds, dairy products, avocados, plant oils, oily fish.

ProteinConstitute 20-25% of diet. (0.8 gm/kg)Preservation of immune functionAids revascularisation and collagen synthesisCell multipicationInvolved in synthesis of enzymes for wound healingHypoproteinaemia delays wound healingDecreases skin and fascial tensile strengthIncreases wound infection ratesDietary sources: meat, chicken, fish, eggs, dairy products, nuts, seed legumes and grains.

WaterWater constitutes 60% of body weightAdequate hydration is essential to maintain skin turgorActs as a solvent for mineral, amino acids & glucoseDehydration can delay wound healing by: blood volume blood circulation O2 and nutrients to tissuesHow much is enough?3035ml/kg/day

Immuno-nutritionNutritional immunology is the science of positive manipulation of immunity using macro or micro nutrients

ImmunonutrientsL- Arginine (Amino Acid/Protein)Enhances protein metabolism & decreased muscle lossStimulation of nitric oxide pathwayImportant in collagen depositionenhances immune systemSecretogogue for regulatory hormones, GH insulinDosage 9-12 gms for 1000 calories

Supplementation may be most beneficial in the first 3 days of wound healing

ImmunonutrientsGlutamine (Amino Acid/Protein)Component of anti-oxidant glutathione for nucleotide synthesisImportant fuel for enterocytes, colonocytes & lymphocytesEnergy for gut and immune cells, maintains gut barrier functionConstitute 30-50% of free amino acids synthesised in skeletal muscleNeeds to be given with adequate protein from other sources supplementary to protein requirements (3.5 gms for 100 gms of protein)

Anti inflammatoryPro-inflammatoryDose 1-4gms/day

NucleotidesIt is essential for RNA & DNA synthesis, cell division, enzyme nutrition.Proliferation & functioning of phagocytes & T cellsAids in liver regenerationPrevent gut mucosal atrophyDose 1-2 gms/day

VitaminIncreases inflammatory response & stimulates collagen synthesisRestore wound healing in diabetics & on steroidsImproves colonic anastamotic healingDeficiency delays wound healing, risk of infectionZn deficiency can impair absorption & metabolism of Vitamin ADietary sources: dairy products, eggs, fish, oranges, dark green vegetables and red fruit and vegetablesDaily requirement 700-3000 IU/day

Vitamin C Essential for collagen synthesis and fibroblast formation, angiogenesisIncreased immunity due to anti-oxidant propertiesIncreases iron absorptionDeficiency results in capillary fragilityDeficiencies can cause breakdown of already healed woundsShould only be supplemented in patients with deficiencyDietary sources: citrus fruits, berries, capsicum, tomato, green leafy vegetablesDaily requirement 60-200mg/day

Vitamin EAnti-oxidantProtects poly unsaturated fatty acids from oxidation by free radicalsDecreases scar formation doubtfulInhibits collagen synthesisDosage 400 mg/day

OthersIn addition Vitamin B is given to enhance nervous & immune function & to accelerate healingVitamin KVitamin DCalcium

SeleniumEssential for activity of glutathione peroxidase first line antioxidant defenceDeficiency may alter immune functionHigh proportion of deficiency in Australian population (deficient soils)Dietary sources: Fish and seafood, nuts, whole grains, meat and poultry, eggs.

ZincRole in protein & collagen synthesis Component of 200 enzymes including DNA polymerase (in cell proliferation)Deficiency = wound strengthOver supplementation will interfere with Cu & Fe absorptionAdequate protein = Adequate ZincDietary sources: eggs, seafood, red meat, poultry, milk products and nutsDosage 15 mg/day

CopperCofactor for several enzymesRole in maturation of collagenImpaired wound healing seen in deficiencyDietary sources: shellfish, whole grains, nuts, seeds, dark green leafy veg, dried fruit.

IronIs a component of Hb oxygen carrierPromotes collagen production & strengthening Increased absorption with vitamin CDosage 8 mg/day

What is nutrition support?An alternate means of providing nutrients to people who cannot eat any or enough food When is it needed?Illness resulting in inability to take in adequate nutrients by mouthIllness or surgery that results in malfunctioning gastrointestinal tractTwo types:Enteral nutritionParenteral nutrition

Indications Patient who cant eatPatient who wont eatPatient who shouldnt eatPatient who cant eat enoughIf the gut works, use it.

IndicationsThose who do not eat: anorexia nervosa, Those who can not eat: esophageal stenosis, prolonged ileus, Those who are not allowed to eat: gastrointestinal fistula, inflammatory bowel disease, radiation enteritis, GI chemo toxicity, pancreatitis, tracheoesophageal fistula, massive intestinal atresia.

IndicationsThose who are not eating enough: short bowel syndrome, burns, sepsisThose who cant manage what they eat: hepatic failureOthers: renal failure, major surgeries.

General Conditions Suggesting Initiation of Nutrition Support Poor nutritional status (oral intake 10%) Anticipated duration of artificial nutrition longer than 7 days More than 7 days inanition Serum albumin 200 mLKeep HOB > 30 at all times

Complications of Enteral NutritionMechanical aspiration, sinusitis, airway obstruction, nasal necrosis, displacement, occlusion of the tube, rarely perforationFunctional nausea, vomiting, abdominal distension, constipation, diarrhea, bacterial overgrowth Metabolic hyperglycemia, hyperosmotic non-ketotic coma

What is parenteral nutrition?Parenteral Nutrition also called "total parenteral nutrition," "TPN," or "hyperalimentation." It is a special liquid mixture given into the blood via a catheter in a vein.The mixture contains all the protein, carbohydrates, fat, vitamins, minerals, and other nutrients needed.

Indications for Parenteral Nutrition SupportMalnourished patient expected to be unable to eat > 5-7 days AND enteral nutrition is contraindicatedPatient failed enteral nutrition trial with appropriate tube placement (post-pyloric)Enteral nutrition is contraindicated or severe GI dysfunction is presentParalytic ileus, mesenteric ischemia, small bowel obstruction, enteric fistula distal to enteral access sites

The gut should always be the preferred route for nutrient administration.

If you are going to start TPN, there needs to be a reason why you cant use EN. THE GOLDEN RULE OF NUTRITION

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PPN vs. TPNTPN (total parenteral nutrition)High glucose concentration (15%-25% final dextrose concentration)Provides a hyperosmolar formulation (1300-1800 mOsm/L)Must be delivered into a large-diameter vein through central line. PPN (peripheral parenteral nutrition)Similar nutrient components as TPN, but lower concentration (5%-10% final dextrose concentration)Osmolarity < 900 mOsm/L (maximum tolerated by a peripheral vein)May be delivered into a peripheral veinBecause of lower concentration, large fluid volumes are needed to provide a comparable calorie and protein dose as TPN

Parenteral Access DevicesPeripheral venous accessCatheter placed percutaneously into a peripheral vesselCentral venous access (catheter tip in SVC)Percutaneous jugular, femoral, or subclavian catheterImplanted ports (surgically placed)PICC (peripherally inserted central catheter)

Writing TPN prescriptionsDetermine total volume of formulation based on individual patient fluid needsDetermine amino acid (protein) contentAdequate to meet patients estimated needsDetermine dextrose (carbohydrate) content~70-80% of non-protein caloriesDetermine lipid (fat) content~20-30% non-protein caloriesDetermine electrolyte needsDetermine acid/base statusCheck to make sure desired formulation will fit in the total volume indicated

Parenteral Nutrition MonitoringCheck daily electrolytes and adjust TPN/PPN electrolyte additives accordinglyCheck glucose 6th hourly Check triglyceride level within 24 hours of starting TPN/PPNCheck LFTs weeklyCheck pre-albumin weekly

Monitoring for Adult Patients on PNParameterBaselineCritically ill pateintsStable patientsChemistry screen (Ca, P, Mg, LFTs)Yes2-3x/weekWeeklyElectrolytes, BUN, CrYesDaily1-2x/weekSerum triglycerideYesWeeklyWeeklyCBC with differentialYesWeeklyWeeklyPT,PTTYesWeeklyWeeklyCapillary glucose3x/day3x/day (until consistently