Hipótesis específica 10

Despite improvements in medical therapy, the rate of surgery in Crohn’s disease after 5–10 years ranges from approximately

20%–30%.536 915 _{Postoperative complications are also more}

common in patients undergoing IBD surgery than operations Good Practice recommendation 21. Patients with IBD should

have an assessment of their general nutritional status and screening for evidence of recent weight loss and/or assessment of malnutrition risk at each clinic appointment and on hospital admissions (Agreement: 95.7%).

statement 102. We recommend that IBD patients who are

malnourished or at risk of malnutrition should have relevant screening blood tests to assess for macronutrient and

micronutrient deficiencies. This may include measurement of iron stores, vitamin B12, folate, vitamins A, C, D and E, potassium, calcium, magnesium, phosphate, zinc and selenium (GRADE: strong recommendation, very low-quality evidence. Agreement: 93.6%).

box 9 Iron deficiency anaemia in Ibd

► A third of patients with active IBD have iron deficiency anaemia

► Anaemia causes fatigue, affects quality of life and delays recovery

► As systemic inflammation inhibits absorption of iron, iron tablets should not be used in those with active disease and, in patients with inactive disease, no more than 100 mg elemental iron should be taken daily899

► Ferritin levels up to 100 µg/L in the presence of inflammation may still reflect iron deficiency.899 _{Measurement of transferrin} saturation may therefore be helpful

► Consider other causes of anaemia (eg, folate deficiency, B12 deficiency or bone marrow depression) in patients with IBD

► Intravenous iron should be used first line in patients intolerant of oral iron who have active IBD and moderate to severe anaemia (Hb <100 g/L), or those who need erythropoietin899

► Iron absorption may be improved by once daily or alternate daily oral dosing1288

statement 103. We suggest that vitamin D levels should

be measured and deficiency corrected in Crohn’s disease and ulcerative colitis (GRADE: weak recommendation, very low-quality evidence. Agreement: 86.7%).

on January 13, 2020 at University of Exeter. Protected by copyright.

for other conditions due to the active inflammation, emergency

setting, complications and drug treatment.916

5.4.1 Preoperative nutritional status

Malnutrition and nutrient deficiencies are common in IBD.917 918 _{Severe malnutrition (BMI <18.5 kg/m}2 _{and recent} weight loss >10% body weight) is associated with a higher risk of postoperative complications, particularly intra-abdominal

sepsis919 _{and increased mortality.}920 _{Poor preoperative nutri-}

tional status has been identified as an independent risk factor for postoperative intra-abdominal septic complications (OR

6.23, 95% CI 1.75 to 22.52) in multivariate analysis.921 _Thus,

all IBD patients undergoing surgery should be assessed for risk of malnutrition. Elective surgery should ideally be post- poned until malnutrition is treated. However, in an emergency situation this may not be feasible, and should be considered in the nature of operation undertaken to minimise risk of complications.

5.4.1.1 Evidence for preoperative nutritional support

There are few prospective studies of preoperative nutrition and no prospective randomised trials with a non-nutrition control group. A meta-analysis of pre-surgical nutritional support in gastrointestinal surgery patients found that the provision of 500–1000 kcal of an immune enhancing oral nutritional supple- ment plus usual food significantly reduced post-surgical compli-

cations.922 _{A more recent systematic review of preoperative}

nutrition in Crohn’s disease included 14 original studies, but

only five prospective studies including one randomised trial.923

Five studies showed significantly reduced complications and infectious episodes in patients receiving preoperative nutritional therapy. Significant heterogeneity was reported between studies in terms of the nutritional supplement used and timing of nutri- tion. There is sufficient evidence to propose delaying surgery when possible to allow a multimodal approach to management including nutrition, steroid weaning and management of any abscesses.

The European Society of Parenteral and Enteral Nutrition (ESPEN) recommends preoperative nutritional support for 7–10 days in patients who are undergoing major gastrointes-

tinal surgery and are mildly malnourished.924 _{A longer duration}

is recommended for severely malnourished patients even if it

delays surgery.924 _{If oral nutritional supplements are not toler-}

ated, then enteral nutrition should be considered and parenteral nutrition should only be used when nutritional targets cannot be

delivered by the enteral route.436 924

5.4.2 Preoperative serum albumin

Hypoalbuminaemia (albumin <30 g/L), as a reflection of signif- icant inflammation or secondary to malabsorption, is frequently associated with severe malnutrition although is not in itself a

marker of nutritional status.919 _{This level of hypoalbuminaemia}

is associated with a higher risk of postoperative intra-abdominal

sepsis.925 _{The evidence to support the use of intravenous albumin}

is weak919 925 _{and correction of hypoalbuminaemia hinges on}

treatment of underlying sepsis and control of inflammation. Nutritional support alone is very unlikely to restore low albumin levels to normal while sepsis and uncontrolled inflammation

persist, but feeding is an important supportive measure.926 927

5.4.3 Preoperative anaemia

Preoperative anaemia (Hb <130 g/L in men and <120 g/L in women) increases the risk of postoperative intra-abdominal sepsis, correction of which is associated with improvement in outcomes including risk of intestinal obstruction and haemor- rhage, anastomotic leak, postoperative perforation, pulmo- nary oedema and septic complications such as pneumonia and

wound infection.925 928 _{Perioperative red cell transfusion in}

patients undergoing ileocaecal resection has been shown to be associated with an increased risk of postoperative complications including an anastomotic leak, ileus, intra-abdominal abscess,

wound dehiscence and thrombotic events.929 _{Anaemia should be}

recognised and treated early, preferably with oral or intravenous iron and other haematinics as needed, and avoiding blood trans- fusion where possible.

5.4.4 Preoperative corticosteroids

Patients undergoing IBD surgery while on corticosteroids have an increased risk of postoperative infectious complications and

anastomotic leaks.930–932 _{There is some evidence that risks are}

greater for those taking high-dose steroids (40 mg prednisolone

or more).932 933 _{A comparison of prednisolone doses greater than}

20 mg versus 20 mg or less did not show a significant difference

in risk of infections.931 _{Use of more than ≥15 mg oral corti-}

costeroid in UC patients within 30 days of IPAA surgery, or more than ≥20 mg in the setting of proctocolectomy, is asso-

ciated with increased risk of complications.934 935 _{IBD patients}

having elective surgery should have their corticosteroids stopped if possible, or brought to as low a dose that can be managed without deterioration.

Patients who are on corticosteroids at the time of their IBD surgery should be given intravenous hydrocortisone in

equivalent dosage until they can resume oral prednisolone.930

Prednisolone 5 mg is equivalent to hydrocortisone 20 mg or statement 104. We suggest that a low FODMAP diet may

be used to treat functional bowel symptoms in IBD patients (GRADE: weak recommendation, low-quality evidence. Agreement: 84.4%).

statement 105. We recommend that IBD patients should have

assessment and optimisation of their physical condition prior to elective surgery. This should include appropriate imaging to determine disease extent and complications; radiological drainage of abscesses and treatment of sepsis; correction of anaemia; treatment of malnutrition and physical mobilisation (GRADE: strong recommendation, very low-quality evidence. Agreement: 97.3%).

statement 106. We recommend that prior to surgery all IBD

patients should have their nutritional status assessed and if at risk of malnutrition should receive nutritional support (oral nutritional supplements or enteral or parenteral nutrition if required) (GRADE: strong recommendation, very low-quality evidence. Agreement: 97.3%).

statement 107. We suggest that patients with penetrating or

stricturing Crohn’s disease, or those who are malnourished, may benefit from exclusive or partial enteral nutrition for at least 6 weeks preoperatively (GRADE: weak recommendation, very low-quality evidence. Agreement: 97.2%).

on January 13, 2020 at University of Exeter. Protected by copyright.

methylprednisolone 4 mg. There is no value increasing steroid dosage to cover stress in the perioperative period, as shown in a

randomised trial in IBD surgery936 _{and case series.}937 _Anaesthe-

tists will generally give a single steroid dose prior to induction (such as dexamethasone 4 mg intravenous or intramuscular) for

those taking more than 5 mg prednisolone.938 _{Patients who are}

on physiological corticosteroid replacement because of disor- ders of the hypothalamic pituitary axis (such as oral hydrocor- tisone 20 mg mane, 10 mg nocte) should receive supplementary

doses in the perioperative period.939 _{For patients who have had}

complete resection of active disease, it is important to avoid inappropriate prolongation of steroids after surgery, and there is virtue in standardised steroid-taper protocols in the postop- erative period, dependent on the dose and duration of steroids

preoperatively (table 11).

5.4.5 Preoperative thiopurines

With one exception,940 _{the literature on the use of immunosup-}

pressive therapy (thiopurines and methotrexate) leading up to surgery does not describe an association with an increased risk

of postoperative complications.932 933 941

5.4.6 Preoperative anti-TNF therapy

The risk of surgical complications for Crohn’s patients taking anti-TNF therapy during the perioperative period has been assessed in many small observational studies. The majority of systematic reviews and meta-analyses conclude that there is a

small increase in risk of infectious complications,257 932 942–945

although one systematic review found no difference.946 _{This risk}

is less than that for corticosteroid use,947 _{and anti-TNF therapy}

alone does not justify the formation of a diverting stoma. Opera- tive risk should be based on other risk factors including presence of fistulae, abscess, low albumin, anaemia and corticosteroid use

in addition to anti-TNF therapy.930 _{There is evidence in Crohn’s}

disease that risk is related to anti-TNF drug levels.948 _{If clinically}

appropriate, cessation should be 6–8 weeks before surgery for infliximab and 4 weeks for adalimumab, but evidence to support this is lacking. If necessary, treatment should be restarted soon after the patient is well enough to be discharged from hospital. For UC, compared with Crohn’s disease there are fewer data on which to assess risk of anti-TNF therapy and studies have methodological limitations, but two meta-analyses conclude that

the postoperative risk is not increased overall.944 949 _Anti-TNF

therapy for Crohn’s patients should therefore be discontinued where possible prior to elective surgery. If not appropriate to stop, then timing of injections should be arranged to have as long a gap as possible prior to the operation. Stopping anti-TNF therapy prior to UC surgery is less critical.

In patients having proctocolectomy, corticosteroids are associ- ated with an increased risk of impaired wound healing and need

for re-operation.935 _{There is no evidence of increased compli-}

cation risk for patients taking immunomodulators (mercapto-

purine, ciclosporin) who have ileoanal pouch surgery950 _{or IBD}

surgery generally.941 _{A two-stage IPAA procedure carries more}

risk than a three-stage procedure if patients are on anti-TNF

therapy.951 _{Pouch surgery is complex with inherent risks, and}

it is prudent to conduct a controlled withdrawal of both corti- costeroids and anti-TNF as part of a staged approach to pouch formation, which should always be done in an elective setting.

5.4.7 Summary of recommendations for operative optimisation

In elective surgery IBD patients should have their physical condition assessed and optimised prior to surgery. This should include assessment of comorbidities; imaging or endoscopy to document disease extent; drainage of abscesses and treatment of sepsis; assessment and correction of nutritional deficiencies; and stopping corticosteroids and biologics where possible. All IBD patients undergoing surgery should follow an enhanced recovery

(ERAS) protocol.436 924 _{A checklist is shown in box 10.}