Parenteral Nutrition An Overview for the Practising Clinician

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Parenteral Nutrition An Overview for the
Practising Clinician
63rd BAMP / UWI CME Conference 16th May 2008 St.
Michael, Barbados

• David Armstrong,
• Division of GastroenterologyMcMaster University
  Hamilton Health SciencesHamilton, Ontario,
  Canada

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McMaster University Medical Centre
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McMaster University Medical Centre
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Parenteral Nutrition - Overview

• Indications, Contraindications and Routes of
  Administration
• Macronutrient and Micronutrient Use in TPN
• Importance of a Parenteral Nutrition Team

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• Death from starvation is as final as death from
  cardiac standstill!

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Starvation

• Adult volunteers
• Fasted for 30-40 days 25 weight loss
• More prolonged fasting 50 weight loss
• Weakness
• Apathy
• Reduced work capacity cardiorespiratory failure
• Total starvation is fatal in 8 to 12 weeks
• IRA Fast (5/91-8/91) death at 45 days (1/10 -
  with gunshot) and 57-73 days (9/10)

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What is Nutritional Support?

• The provision of nutrients orally, enterally or
  parenterally with therapeutic intent.
• This includes, but is not limited to, provision
  of total enteral or parenteral nutrition support,
  and provision of therapeutic nutrients to
  maintain and /or restore optimal nutrition status
  and health.
• ASPEN, 2002

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Who Should Get Nutritional Support?

• Patients who
• Cannot meet nutrient requirements
• Have documented inadequate oral intake
• Have unpredictable return of GI function
• Need a prolonged period of NPO/bowel rest

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Enteral (GI Tract) versus Parenteral (IV)
Nutrition

• Not a flip of the coin decision
• If the gut works, use it!

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Parenteral Nutrition
Magic!

• 23-year old female with Crohns disease
• Obstruction and perforation ICU post-op
• NPO for 3 weeks, sepsis, weight loss 30 lb
• Does she need TPN, Sir? Yes, Armstrong!
• How do we give TPN?
• What should we give and how much?
• What do we need to monitor?
• Who can help us with this?
• Youll have to read it up, Im afraid Ive
  never done this and I dont know anyone who has!

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Common Indications for PN

• Inability to absorb adequate nutrients via the GI
  tract
• Massive small-bowel resection / short bowel
  syndrome
• Severe, untreatable steatorrhea / diarrhoea /
  malabsorption
• Complete bowel obstruction, or intestinal
  pseudo-obstruction
• Prolonged acute abdomen or ileus
• Severe catabolism GI tract unusable within 57
  days
• Enteral access not feasible, not adequate or not
  tolerated
• Pancreatitis with intolerance (eg pain) of
  jejunal nutrition
• High output EC fistula (gt500 mL) no distal
  enteral access

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Potential Indications for PN

• Enterocutaneous fistula
• IBD unresponsive to medical therapy
• Hyperemesis gravidarum persistent for gt 57
  days and enteral nutrition not possible
• Partial small bowel obstruction
• Intensive chemotherapy / severe mucositis
• Major surgery if enteral nutrition unlikely for
  gt710 days
• Intractable vomiting if jejunal feeding not
  possible
• Chylous ascites or chylothorax when low

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Contra-indications to PN

• Functioning gastrointestinal tract
• Treatment anticipated for lt 5 days in patients
  without severe malnutrition
• Inability to obtain venous access
• Poor prognosis that does not warrant aggressive
  nutrition support
• When the risks of PN are judged to exceed the
  potential benefits

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Who Needs PN?Assessing Nutritional Status

• Focused nutrition history
• Assess current weight and weight-loss history
• Physical examination
• Assess malabsorption
• Fecal fat test
• Schilling test
• Hydrogen breath test
• D-xylose
• SGA Subjective Global Assessment

Bashir S, et al. Prim Care 200128629-645.
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Assessing Nutritional StatusThe SGA

• A. History
• Weight change lt5 small510 potentially
  significant gt10 definitely significant
• Change in dietary intake
• Gastrointestinal symptoms(nausea, vomiting,
  diarrhea, anorexia)
• Functional capacity
• Disease and its relation to nutritional
  requirements

• B. Physical
• Loss of subcutaneous fat
• Muscle wasting
• Ankle edema
• Sacral edema
• Ascites
• C. SGA Rating
• A Well nourished
• B Moderately malnourished
• C Severely malnourished

Detsky AS et al. JPEN 1987118-13.
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How Do We Give PN?
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Administration of PN

• PN solutions are hypertonic
• Infusion, therefore, via
• Central venous catheter, or
• Peripheral venous catheter with reduced
  osmolarity

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Percutaneous CentralVenous Access

• Peripherally inserted central catheters PICC
• Placed at bedside or radiologically
• Subclavian vein used to be most common
• Can be placed removed at bedside, but
• Generally, placed radiologically
• Confirm placement with chest x-ray
• Can change over a wire to replace

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Implanted Central Venous Catheters (e.g. Hickman,
Groshong, Port-A-Cath)

• For prolonged TPN
• Also for fluids, chemotherapy, blood draws
• Catheter inserted operatively
• Placed with fluoroscopic guidance
• Implanted into a subcutaneous tunnel

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Peripherally Inserted Central Catheter (P.I.C.C.)
Line

• More expensive than peripheral lines
• More difficult to place
• Last up to 6 - 12 months
• Restrict arm movement
• Allow higher osmolarity Central TPN
  solutions

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Tunnelled (Hickman) Line
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Implanted Venous Access Device
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Peripheral IV short-line

• PROS
• Least expensive
• Easily placed and removed
• Lowest risk for CRI
• Beneficial for short-term support (lt 1 week)

• CONS
• Need to change often
• Every 48-72h
• Phlebitis and vein injury
• Only one lumen
• Limits energy delivery
• Volume
• Osmolality (600-900 mOsm/l)
• pH restriction (pH 5-9)

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Peripheral IV mid-line

• PROS
• May be used for a longer duration than peripheral
• Ease of placement compared to central lines
• Allows access to larger vessel

• CONS
• Not a central line
• Must follow guidelines for peripheral lines for
  concentration, pH and infusion rates

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Central IV PICC

• PROS
• Can infuse solutionsgt 900 mOsmol/l
• May be placed by RN
• Decreased CRI vs other central lines HPN
• Can be multi-lumen
• Usable for CT contrast

• CONS
• Shorter life than other central lines (lt 12 m)
• More difficult self care
• Blood sampling not always possible
• More frequent flushing and maintenance
• More painful

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Central IV Hickman / Brovac

• PROS
• Can infuse solutionsgt 900 mOsmol/l
• Allow full IV nutritional support
• Can be multi-lumen
• Longevity 1 -3 years
• Easier self-care (than PICC , possibly, port)

• CONS
• Surgical / Radiological procedure
• More complex
• More difficult to remove
• Tube protruding from chest may affect body image
• More restrictive than a port

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Central IV Implantable Port

• PROS
• Can infuse solutionsgt 900 mOsmol/l
• Allow full IV nutritional support
• Greatest longevity
• Easier self-care (only needed if accessed)
• Improved body image activity

• CONS
• Surgical / Radiological procedure
• More complex
• More difficult to remove
• Access requires placement of a Huber needle
• Infection risk during access

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Complications of PN

• Infectious
• e.g. Catheter and systemic infections
• Mechanical
• e.g. Catheter obstruction, Hydrothorax,
  Venous thrombosis
• Metabolic
• e.g. Bone disease, Hepatobiliary disease,
  Renal disease

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Complications of PN Catheters

• Catheter infections
• Catheter occlusion
• Catheter injury/leakage
• Catheter migration
• Venous thrombosis
• Catateher line true story!

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Venous Access Line Blockage

• Check hub / line integrity / phlebotomy
• Careful flushing
• Doppler study Linogram
• Lipid - 70 EtOH
• Calcium / mineral - HCl (0.1 N)
• Thrombus - (Urokinase - 5000U) or tPa
• Prophylaxis - flushing after cap-off

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Catheter-related infections

• Skin commensals (S. epidermidis, S. aureus,
  Candida spp) Intestinal flora (Ps spp, Candida)
• Monitor temp (blood culture if gt38.5oC)
• Culture - central and peripheral - 51 CFU ratio
  implicates central line (Vanhuynegem, 1988,
  Surgery)
• 2/3 can be cleared by antibiotics and local care
  (Benezra, 1988, Am J Med)
• Antibiotic lock - 4d Rx 10d 12-h lock (90
  clear)

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Risk Factors for Infection

• Site - Subclavian lt Int. jugular lt Femoral
• Material - Silastic / Polyurethane lt PVC
• Type - Subclavian (0.9) lt PICC (1.4 / 1000d)
  - Single lumen lt Multi-lumen
• Care - 2 chlorhexidine (5.9 catheter
  colonisation) 70 isopropyl alcohol
  (15.6) 10 povidone iodine (19.5)
• Patient - young, poor technique, smoking,
  Crohns, jejunostomy, thrombosis, narcotics

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Parenteral Nutrition - Overview

• Indications, Contraindications and Routes of
  Administration
• Macronutrient and Micronutrient Use in TPN
• Importance of a Parenteral Nutrition Team

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Designing Parenteral Regimens

• Assess nutritional status and set goals.
• Evaluate constraints on nutrient delivery.
• Assess fluid, electrolyte, vitamin, trace element
  requirements
• Order nutrients (protein, CHO, fat), fluids/
  electrolytes/ trace elements
• Determine administration (rate and duration).
• Avoid metabolic complications.

http//www.globalrph.com/tpn.htm
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Parenteral Nutrition

• Carbohydrate (10 - 25 Dextrose)
• Amino Acids (0.8 to 1.2 g /kg)
• Lipid Emulsion, incl E.F.A. (10 - 30)
• Vitamins / Minerals / Trace Elements
• Electrolytes
• Fluid (2 - 3 litres /day)

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How Much Should We Give?
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Nutritional AssessmentThe Eggs-Benedict
Equation (EBE)
A-Asparagus B- Bacon C-Cholesterol
E.B.E. 0.43A 1.56B 4.57C
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Nutritional Assessment

• Dietary Intake Assessment (3-day recall)
• Weight Weight loss (v. IBW / UBW)
• Harris-Benedict Equation Stress factor
• Blood tests CBC, Albumin, Electrolytes, Vitamins
  A, B12, D E, Fe, Ca, Mg
• (Indirect Calorimetry)
• (Anthropometry)
• (Nitrogen Balance)

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Estimate of Requirements

• Most hospitalized patients will require 30
  kcals/kg/d
• CHO can utilise dextrose up to 5 mg/kg/min
• Protein The average patient requires 0.8 2.0
  g protein/kg usual body weight

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Constraints on Nutrient Delivery

• Do not overload bodys disposal systems
• renal, hepatic, respiratory
• Nutritional regimen should make sense clinically

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Constraints on Nutrient Delivery

• Protein
• Renal failure without dialysis or with
  ineffective dialysis
• Hepatic encephalopathy
• Intractable negative nitrogen balance

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Constraints on Nutrient Delivery

• Carbohydrates
• Oxidative limit 7 gm/kg/day
• Glucose intolerance
• Minimum of 200 gm if large wound present
• Lipid
• Oxidative limit 2.5 gm/kg/day
• Hyperlipidemia

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Constraints on Nutrient Delivery

• Fluid
• Fluid overload
• Renal insufficiency/failure
• Congestive heart failure
• Pulmonary edema
• ARDS

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Composition of Standard Parenteral Dextrose
Solutions

• 5 - 70 solution dextrose in water
• 3.4 kcal/gm
• 500 ml of a 50 solution contains
• 50 gm/100 ml x 500 ml 250 gm dextrose
• 250 gm x 3.4 kcal/gm 850 kcal

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Composition of Standard Parenteral Amino Acid
Solutions

• Synthetic crystalline amino acids
• Contain essential and non-essential AA
• Variable amounts of electrolytes
• Concentrations depend on final volume
• Hypertonic solutions

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Characteristics ofIntravenous Lipid Emulsions

• Concentrations 10 and 20
• Parent oil Soybean or Safflower
• Osmolarity 280 - 340 mOsm/l
• Caloric content 10 1.1 kcal/ml 20 2.0
  kcal/ml

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Electrolytes in Parenteral Nutrition Solutions

• Appropriate prescription requires regular
  monitoring
• For maintenance provision
• Add directly to the PN solution
• Tailor to individual patient needs
• Additional replacement for abnormal losses
• Deletions for patients with certain diseases

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Vitamins/Trace Elements in Parenteral Nutrition
Solutions

• Meet established guidelines for PN
• Water and fat-soluble vitamins provided
• Required for zinc, copper, manganese, chromium
  selenium
• Added daily to the solution
• Requirements may be increased for patients with
  abnormal losses

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Administration of Parenteral Nutrition Rate and
Duration

• Administer, initially, over 24 hours
• Restrict the rate if regimen is not tolerated
• If patient is stable and tolerates regimen, a
  cycling regimen may provide greater freedom,
  comfort and ease of care

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3-in-1 (T.N.A.) vs 3-in-2

• Advantages
• Cost (fewer supplies)
• Convenience
• More balanced delivery
• Better lipid tolerance
• Decreased potential for contamination

• Disadvantages
• Solution instability
• Incr. bacterial growth
• Cant use 0.22um filter
• Obscures precipitates
• Potential catheter occlusion

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Metabolic Complications of Parenteral Nutrition
1

• Electrolyte imbalance
• Na, K, Mg, PO4, Ca
• Hyperglycemia / hypoglycemia
• Dehydration
• Fluid Overload
• Metabolic Acidosis

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Metabolic Complications of Parenteral Nutrition -
2

• Hyperlipidemia
• Hypercapnea
• Vitamin/trace element deficiencies
• Essential fatty acid deficiency
• Liver dysfunction

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Micronutrient Deficiencies - I

• Essential Fatty Acids Scaly dermatitis
• Zinc Growth retardation
• Copper Anemia, Leukopenia
• Chromium Glucose intolerance, Neuropathy
• Molybdenum Confusion, Cholestasis
• Selenium (Cardio)myopathy

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Micronutrient Deficiencies - II

• Vitamin A Night blindness, keratosis
• Vitamin D Osteomalacia, Muscle weakness
• Vitamin E Retinal posterior column nuclei
  dystrophy,
• Vitamin K Bleeding diathesis
• Biotin Alopecia, Dermatitis, Neuritis
• Carnitine Abnormal LFTs

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Hepatic Disease

• Cholestasis (incl sludge) Hepatocellular
  disease
• Impaired hepatic transulfuration
• Transulfuration products facilitate
• Fat mobilisation
• Lipid membrane stability
• Bile secretion
• May progress to liver failure / transplantation
• Treatment - do not overfeed - ursodeoxycholic
  acid - enteral supplements - carnitine

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Monitoring Patients on Parenteral Nutrition

• Clinical status
• Metabolic and biochemical aspects
• Delivery
• Catheter care, pump, volume infused
• Nutritional status/reassessment

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Parenteral Nutrition - Overview

• Indications, Contraindications and Routes of
  Administration
• Macronutrient and Micronutrient Use in TPN
• Importance of a Parenteral Nutrition Team

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The Need to Monitor NutritionU.K. NICE

• Malnutrition is common
• Malnutrition increases a patients vulnerability
  to ill health
• Nutrition in hospital is often inadequate
• Decisions on providing nutrition support are
  complex
• Nutritional care standards are highly variable

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Organisation of Nutrition Support
U.K. NICE
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What Needs to Happen?

• Screen
• Recognise who is malnourished and who is at risk
• Treat oral, enteral or parenteral
• Monitor and review
• This needs a multidisciplinary team
• But ... What is expected of a (PN) team?

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Goals of Inpatient Nutrition Delivery

• Identify patients at nutritional risk
• Identify need for nutritional support
• When to start
• When to stop
• Identify appropriate means of nutritional support
• Most cost-effective, least invasive intervention
• Identify and prevent complications of nutritional
  support
• Maintain safe vascular or enteral access
• Prevent / treat infection, thrombosis, metabolic
  complications
• Provide safe parenteral nutrition solutions

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Parenteral Nutrition Requirements

• Knowledge of
• Patients clinical status RN, MD
• Current
• Goals
• Patients nutritional status RD, RN
• Patients nutritional requirements RD
• Patients vascular access status RN, MD
• Parenteral solution compounding options BPharm

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St. Bartholomews Hospital/Science Photo Library
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Parenteral Nutrition TeamPossible Members

• Nutritionist expertise across PN, EN, short
  bowel
• Pharmacist with nutritional / PN expertise
• Physician with nutritional expertise
• Specialist Nutrition Support Nurse
• Support groups
• Vascular access team PICC lines
• Diagnostic imaging Central lines / ports
• Infectious diseases
• Enterostomal therapy
• Surgery

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Are TPN Teams Beneficial?

• Background
• TPN is a specialised, complex form of nutritional
  support
• This has led to the development of
  multidisciplinary TPN teams
• Are TPN teams effective for adult inpatients?
• Methods
• Systematic reivew of studies identified from
  Cochrane library, CINAHL, Medline, Embase,
  Complete Biomedical and Nursing Collections,
  published in any language

Naylor C et al, JPEN 200428251-258.
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Are TPN Teams Beneficial?

• Results
• 48 studies identified
• Eleven eligible studies (No RCTs)
• 4 with concurrent controls
• 7 with historical controls
• TPN Team associated with
• Reduced total mechanical complications
• Fewer total metabolic electrolyte abnormalities
• Greater likelihood of receiving optimal caloric
  intake

Naylor C et al, JPEN 200428251-258.
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Are TPN Teams Beneficial?

• Results
• Inconclusive results were seen regarding
• Reduction in catheter-related sepsis
• Reduction of inappropriate TPN usage
• Cost-effectiveness studies (n2, 356 patients)
  suggest that TPN team is effective
• Conclusion
• Overall, the effectiveness of TPN teams has not
  been conclusively demonstrated .. although
  there are potential benefits in several areas

Naylor C et al, JPEN 200428251-258.
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Are TPN Teams Beneficial?

• Thesis the only acceptable study outcomes are
  mortality, morbidity cost-effectiveness
  (Koretz)
• Only evidence-based interventions should be
  adopted
• TPN is a complex intervention in a small number
  of patients who have serious underlying disease
• Standardisation of interventions is difficult
• Measurement of specified outcomes is difficult
• What is a TPN team and what is the comparator?
• One healthcare professional cannot, reasonably,
  manage all aspects of PN delivery

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Are TPN Teams Beneficial?

• What is the evidence that a police force reduces
  crime or is cost-effective?
• What is the evidence that a hospital
  accreditation team reduces death rates or is cost
  effective?
• What is the evidence that sending a player off in
  a team sport is harmful?
• Absence of evidence of benefit is NOT evidence
  of absence of benefit.

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Parenteral Nutrition - Conclusion

• Is critical for malnourished patients who cannot
  achieve adequate oral / enteral intake
• Short-term inpatients
• Medium- to long-term Home PN allows patients
  awaiting surgery patients with intestinal
  failure to live at home
• Requires meticulous attention to detail
• Requires recognition of risks and benefits
• Is a Team Game requires a Game Plan

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UK NICE Guidelines

• Do not let your patients starve and when you
  offer them nutrition support, do so by the
  safest, most simplest, effective route.
• This is essential to good patient care.
• Mike StroudChair, Guideline Development Group

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Hamilton, Ontario, Canada
Thank You!
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(No Transcript)
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Goals of Nutrition Support

• To minimize protein breakdown,
• To preserve lean body mass,
• To promote protein synthesis, and
• To optimize immune responses

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PN Summary Guidelines

• Determine if PN is truly indicated
• Assess the patient (medical history, medication
  profile, anthropometric data lab values)
• Determine need for long-term vs. short term
• lt710 days
• Confirm or establish adequate IV access
• Peripheral or central?
• Determine estimated kcal, protein and lipid needs
• 2030 kcal/kg
• Protein 0.81.5 gm/kg
• Higher levels may be needed in severe catabolic
  states
• Lipid to provide 30 of kcals

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PN Summary Guidelines

• Determine initial electrolyte, vitamin and trace
  element requirements consider ongoing losses
• Consider any additional additives to PN
  formulation including insulin and H2-receptor
  antagonists
• Monitor for
• Risk of refeeding syndrome
• Glucose intolerance
• Start low advance slowly if labs stable over
  24-48 hours
• Fluid, electrolyte, metabolic, macro- and
  micro-nutrient changes
• Complications sepsis, thrombosis, abuse
• Initiate trophic feedings or convert patient to
  PO or enteral feeding when feasible

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Intravenous Vitamins RDI (ASPEN)

• Vitamin RDI (FDA/AMA/NAG)
• Thiamine (B1) 6 mg
• Riboflavin (B2) 3.6 mg
• Pyridoxine (B6) 6 mg
• Cyanocobalamin (B12) 5 mcg
• Niacin 40 mg
• Folic acid 600 mcg
• Pantothenic acid 15 mg
• Biotin 60 mcg
• Ascorbic acid (C) 200 mg
• Vitamin A 3300 IU
• Vitamin D 5 mg
• Vitamin E 10 IU
• Vitamin K 150 mcg

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Metabolic Bone Disease

• Pre-existing disease malabsorption
• Aluminium contamination
• Inadequate calcium provision
• Excess Vitamin D in TPN - measure both 25-OH
  1,25 DHCC
• Monitor DEXA, Ca, Vit D, PTH, Albumin

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The Whole Team Makes it HappenThe U.K. NICE

• Healthcare professionals involved in patient care
  should receive education and training on
  nutrition support
• All people needing nutrition support should
  receive coordinated care from a multidisciplinary
  team
• Acute care hospitals should employ at least one
  specialist nutrition support nurse
• Hospitals should have a nutrition steering
  committee working within the clinical governance
  framework

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Possible ComplicationsAssociated with Long-Term
TPN

• Gastrointestinal dysfunction
• Trace element deficiencies
• Hepatic steatosis/cholestasis
• Metabolic bone disease
• Psychosocial difficulties
• Financial difficulties

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Valved Groshong Line
Groshong Valve

• At rest valve is closed and no blood leaks
  out
• On infusion valve leaflets are pushed out by
  infusion solution
• On aspiration valve leaflets are pulled in by
  negative pressure and blood returns

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Normal Serum ElectrolytesParenteral Enteral
Intake Ranges
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Adult RDI of IV Trace Minerals
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Monitoring PN PatientsClinical Status

• Vital signs
• Intake/output
• Urine, Stool, Other (eg fistula output)
• Weight
• Fluid requirements
• Patient complaints
• Physical exam
• Overall clinical status

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Monitoring PN PatientsMetabolic and Biochemical
Aspects

• Blood studies
• Renal function Lytes, Mg, Ca, Phos, BUN, Cr
• Hematologic CBC (Hgb, WBC, Plt), INR
• Liver function Alk Phos, AST/ALT, Bilirubin
• Glucose/lipid tolerance Glucose, Triglycerides
• Iron status Iron, TIBC, Ferritin
• Serum proteins Albumin
• Insulin coverage
• DEXA