A teaching session designed for junior doctors as an introduction to clinical nutrition, incorporating real-life case studies.

1. Dr. Sharma
IMT2 Gastroenterology
Cases in Clinical Nutrition

2. Objectives
1. To be aware of the various causes of malnutrition.
2. To appreciate the consequences of malnutrition in the
hospitalised patient.
3. To have an awareness of what methods of nutritional
support are available and when each is indicated. (N.B.
This presentation is simply a primer!)
4. To be able to apply the above principles to real-life
clinical scenarios.

3. Consequences
of malnutrition

4. Risk
factors
for
↓dietary
intake
Poor diet/catering
Reduced appetite
Poor dentition
Difficulty feeding self
Pain/nausea
Mucositis
Dysphagia
Depression/anorexia/dementia
Loss of consciousness

5. Risk factors for ↑ nutritional requirements
Illness Surgery
Organ
dysfunction

6. Risk factors for ↓
absorption/utilisation
of nutrients

7. Risk
factors
for ↑
losses
Vomiting/ileus
Diarrhoea
Fistulae
Stomas
Surgical drains
Burns
Nephrotic syndrome

9. MUST Scoring

11. Calculating nutritional
requirements:
• For patients who are not severely ill or at risk of
refeeding syndrome:
• 25-35 kcal/kg/day total energy INCLUDING that
derived from protein
• 0.8-1.5g of protein/kg/day OR 0.13-0.24g nitrogen
/kg (equivalent)
• Little benefit to providing >0.2 g
nitrogen/kg/day IF UNWELL as these patients
are unable to cope with high nitrogen loads
• Provide up to 0.3g nitrogen/kg/day for patients
in anabolic phase of recovery
• 30-35 mL/kg/day of fluid
• Adequate electrolytes, minerals, micronutrients and
fibre allowing for pre-existing deficits

12. For patients who are severely unwell/at risk of
refeeding…
Start no more than at 50% of the
estimated target energy and
protein requirements
Full requirements for
fluid/electrolyte/vitamin/minerals
should still be met

17. Methods of nutritional replacement
Oral supplementation
Enteral feeding (nasogastric,
nasojejunal, percutaneous
gastrostomy +/- jejunal
extension)
• Indication: Inadequate oral
intake, mechanical
obstruction, high aspiration
risk
• Indication for PEG: > 6 week
requirements for enteral
feeding
Parenteral feeding (total
parenteral nutrition or ‘TPN’)
• Indication: Short bowel
syndrome, bowel
obstruction/perforation,
active GI bleeding

19. Nasogastric
feeding
Short-term feeding – days-to-weeks
Longer term feeding in children
Contraindications: Basal skull #,
NP/oesophageal pathology
Relative contraindications: Nasal
problems incl. bleeds and deviated
septum; previous traumatic insertion

20. Nasojejunal feeding (post-pyloric)
 Short-term – days-to-weeks
 Delayed gastric emptying
 Reflux resulting in increased aspiration
risk
 Upper GI tract surgery
 Pancreatitis
 Intractable vomiting e.g. hyperemesis
gravidarum
 Absolute contraindications- as per NG
feeding, gastric outflow obstruction
prevent passage of tube
 Relative - as per NG, inability to pass
endoscopically

21. Absolute contra-
indications for
enteral feeding
Intestinal obstruction
Severe ileus
Intestinal perforation
Proximal GI tract fistula – unless
feeding is distal to the fistula
Refusal in a competent patient
• Relative contra-indications
• Terminal illness

22. Types of
feed
Requirements
•Standard oral/enteral – 1 kcal/ml
•High energy – 2 kcal/ml
Polymeric (whole protein) vs. peptide/semi-elemental/elemental
Nutritional “completeness”
Fibre-enriched
Fluid/electrolyte restrictions
•Sodium – varies from 1.1 to 6.3 mM/100 kcal; low sodium feed can be given for
salt-restricted patients e.g. CLD
•Potassium content varies from 1.6-6mM/100 kcal
•Osmolality – standard 1 kcal/ml have osmolality of 300 mOsm/kg
•Renal and elemental feeds can be up to 720mOsm/kg
•Peptide/elemental feeds – better-tolerated in patients with malabsorption
•Immune-modulating – may reduce infectious complications in GI surgery/trauma
patients
Glutamine-enriched

23. Gastrostomy
(PEG/RIG/surgical)
 Long-term feeding >30 days
 Benefit in terms of quality of life and
improved disease outcome – e.g. head
and neck cancers
 Improvement in rehabilitation
potential
 Contraindications: Unable to pass
endoscope/NG tube due to
obstructing pathology, gastric outflow
obstruction, planning curative
oesophageal resection
 Relative contraindications:
Coagulopathy, portal HTN, peritoneal
dialysis, gastroparesis, gastric
ulcers/malignancy, gastrectomy,
severe obesity, oropharyngeal or
oesophageal obstruction, active
systemic infection

24. Parenteral nutrition
 Short bowel syndrome
 Intestinal atresia
 Proximal GI tract fistulae
 Radiation enteritis
 Severe chemotherapy-induced
mucositis
 Motility disorders e.g. pseudo-
obstruction, visceral
myopathy/neuropathy
 Extensive Crohn’s disease
 Gut obstructive
 Extensive mucosal disease
• Short-term use <2 weeks: PICC
If long-term >4 weeks – should be
given via tunnelled CVC

25. Case 1
• 27 Female
• Hyperemesis gravidarum (started vomiting from 26/52
onwards during recent pregnancy; also occurred during
first pregnancy 9 years previously)
• Gastro-oesophageal reflux disease
• Daily vomiting during pregnancy
• Refractory to anti-emetics and some response to steroids
• Persisted post-partum
• Suffered with vomiting intermittently over the years –
previously attributed to red-bull addiction

26. Case (cont.)
• Bowels open once per week (normal for her)
• Weight 68.3 kg in clinic (BMI 24)
• Nocturnal reflux symptoms
• From clinic:
• Trial of high-dose PPI and metoclopramide
• OGD requested
• For gastric emptying studies if this is normal

27. What’s going on?
ANY THOUGHTS SO FAR? DOES THIS LADY REQUIRE
NUTRITIONAL SUPPORT?

28. Investigations
OGD – widely dilated
oesophagus with tight
GOJ
NG tube trialled but not
tolerated

30. Barium
meal

31. Case (cont.)
Manometry
confirms
achalasia
Referred to
upper GI
surgeons
Botox,
dilatation,
POEM and
Heller myotomy
all discussed as
options
Patient
consented for
myotomy

32. What’s going on?
ANY REFLECTIONS?

33. Case 2
• Asthma
• C-section
• Current smoker
49 Female
• Presented to department with several days’ history of cramping
RUQ pain
• Distended and tympanic abdomen
• BNO in 3-4/7
• Vomiting
• Tachycardic on presentation but observations otherwise within
normal limits
History

34. Case (cont.)
• Acute appendicitis with secondary small bowel
obstruction
• Reactive colitis in parts of colonic loops
Imaging
• Emergency laparotomy, appendectectomy and 4-
quadrants washout with abdominal drain and
rectus sheath catheter left in-situ
• Generalised peritonitis
• Perforated, gangrenous appendix with
inflammatory changes in RIF
• Small bowel obstruction (reactive secondary
ileus)
• NG inserted in theatre
Treatment

36. Case (cont.)
• ITU admission
• Cautious fluid boluses and metaraminol infusion
• IV antibiotics
• Hypokalaemia and hypomagnesemia corrected
intravenously
• Pabrinex

37. Dietetic
assessment
Anthropometry
• MUST 07/10/21: Wt 43.3kg, Ht 1.55m, BMI:
18kg/m2
• Patient reports normal weight ~ 46.3kg (6.5% loss).
Assessment
• Symptoms started PM of 02/10; minimal - nil intake
for at least 6 days now; refeeding risk.
• Pt aware for PN and sips only over weekend.
Requirements
• 20-25kcal/kg x PAL 1.1 = 953-1191kcal RF: ~433kcal.
• 1.2-1.5g/kg = 52-65g Protein 8.3-10.4g nitrogen
• Baseline: 43mmol Na, 43mmol K, 21.7-30.3mmol
PO4, 4.3-6.5mmol Ca, 4.3-8.7mmol Mg.

38. Dietetic
assessment
(cont.)
Dietetic dx: compromised
nutritional status 2' recent
surgery and unsafe enteral
route 2' ileus. Low BMI.
Outcomes: meet 50% est
requirements / electrolyte
stability / optimise glycaemic
control.

39. PN –
commenced
8/11/2021
• Plan
• 1. Commence PN: HALF BAG: Nutriflex peri ~625mls,
478kcal, 2.9g N, 25mmol Na, 15mmol K, 1.5mml Ca
3mmol Mg, 5.6mmol PO4; x24 hours Friday; x20 hours
Saturday and Sunday.
• - Ensure via dedicated access - note PICC ordered (if
unable to place then bag can be given via dedicated
peripheral access)
• - The actual content of the bag may vary slightly for
fluid and electrolytes so please check PN prescription
for final details
• 2. REFEED risk; continue Pabrinex and daily nutrition
bloods - continue to replace as required.
• 3. Monitor BGLs, bowels and fluid balance including
ryles output.

40. Case (cont.)
• Stepdown to ward after 2 days on
ITU
• Ended up having full bags of PN
over weekend in addition to a full
meal, with no monitoring of
nutritional bloods for 3 days
• Dietitian review on Monday –
advised repeating ALL nutritional
bloods

41. Potassium

42. Magnesium

43. Calcium

44. Phosphate

45. Nutritional profile
Magnesium
Calcium
Phosphate
Albumin
• Haematinics, calcium, zinc,
vitamin B and fat-soluble
vitamins may also be tested.
• At-risk patients:
• Short bowel syndrome
• Alcohol-dependent patients

47. Refeeding
syndrome
• Hypokalaemia
• Hypomagnesaemia
• Hypophosphatemia
• Hyperglycaemia
• Thiamine deficiency
• Na+ and H2O retention  cardiac failure
Management
• Vitamin B1 replacement (Pabrinex/thiamine)
• Electrolyte replacement (oral/IV as per hospital protocol)
• Regular monitoring

48. Risk factors
for refeeding
syndrome
• BMI < 16
• Unintentional weight loss > 15% over 3-6 months
• Little or no nutritional intake for > 10 days
• Low levels of potassium, magnesium or
phosphate prior to feeding
> 1 of:
• BMI < 18.5
• Unintentional weight loss > 10% over 3-6 months
• Little or no nutritional intake for > 5 days
• History of alcohol or drugs, including
chemotherapy, diuretics, antacids or insulin
> 2 of:

52. Case (cont.)
• PN stopped on 12/10 and normal
diet resumed
• Eating and drinking but not
sufficiently
• Est Requirements: Nil
change 1565kcal, 65g pro
• Est Intake: ~600kcals and ~20g
protein
• Est Deficit: 900kcals and 45g
protein
• Commenced on oral nutritional
supplements
• Discharged when clinically and
nutritionally stabilised with
community dietetic follow-up

53. Case 3
• 66 Male
• IHD, prev PCIHFrEF - Mod-severe LVSD
• Previous left ventricular mural thrombus
• Hypertension
• Previous bariatric surgery (gastric sleeve
and duodenal switch, 2004)
• COPD
• Likely congestive hepatopathy
• Admitted with presyncope, hypotension and
hypothermia
• Persistent watery diarrhoea
• Recent admission – watery diarrhoea, weight
loss and difficulty coping at home

54. Case (cont.)
Previously stable weight 61-63 kg 2018-19
Presented with weight loss and diarrhoea and
associated electrolyte disturbances – 49 kg
Faecal elastase, calprotectin and occult blood test
sent during admission – NAD
AXR – ileus. No obstruction on CT
Recent sigmoidoscopy – biopsies obtained
unremarkable
Commenced on TPN

55. Discharged on home
PN

56. SECRETORY
• Definition: Damaged intestinal wall, leading to ↑ secretion and
↓ absorption of electrolytes into GI tract
Large volume, persisting despite fasting
CAUSES
Bowel resection
Chronic alcohol excess
Neuroendocrine tumours e.g. carcinoid
Systemic endocrine pathology e.g. hyperthyroidism, Addison’s disease
Stimulant laxatives
Small intestinal bacterial overgrowth (SIBO)
Bile salt acid malabsorption (ileal resection, post-cholecystectomy)
Infection e.g. giardiasis, cryptosporidiosis

57. OSMOTIC
• Definition: Non-absorbable solute pulls ↑ H2O into GI tract
Tends to be postprandial, resolving with fasting
CAUSES
Osmotic laxatives e.g. lactulose
Drugs e.g. magnesium, phosphate supplements
Undigested sugars (e.g. lactase deficiency)

58. Intestinal failure
• Inability of the gut to absorb:
• Water
• Macronutrients
• Micronutrients
• Protein
• Fat
• Electrolytes
• Most commonly caused by short
bowel syndrome
• < 2 m of functioning bowel
remaining
• Usually occurs after small bowel
resection (often for Crohn’s
disease)
• ↓ Vitamin B12 absorption

59. Duodeno-
ileostomy
Ileo-ileostomy

60. Bariatric surgeries
Restrictive vs. malabsorptive
• Alimentary limb – 200 cm
• Common limb – 100 cm (short for bariatric surgeries)
• Good outcomes in terms of maintaining weight loss, but high rate of fat-
soluble deficiencies, hyperparathyroidism and 14% revision rate due to
nutritional complications (protein deficiencies 30%; anaemia 40%)
• Steatorrhoea and fat-soluble vitamin deficiencies
• Now plays a minor role in part of bariatric procedures worldwide
Biliopancreatic diversion (with duodenal switch)

61. N.B. Type 1 is often postoperative (i.e. postoperative paralytic ileus).

62. In summary…
Each patient requires an individualised dietetic assessment to ascertain
their specific nutritional requirements.
Careful monitoring of electrolytes is required in any patient
commencing parenteral nutrition.
Be careful not to anchor your diagnosis too quickly and ensure that
organic, structural causes for the patients’ presentation are excluded.

63. Sources
• BAPEN e-Learning modules (highly
recommended)
• Felsenreich DM, Langer FB, Eichelter J, et
al. Bariatric Surgery-How Much
Malabsorption Do We Need?-A Review of
Various Limb Lengths in Different Gastric
Bypass Procedures. J Clin Med.
2021;10(4):674. Published 2021 Feb 10.
doi:10.3390/jcm10040674