Pre-operative

This pathway demonstrates the approach to anaemia or iron deficiency if detected at pre-assessment. The pre-assessment team will give the patient a letter to present to their GP indicating that anaemia or iron deficiency is present and requires further action. The patient will be contacted by pre-assessment six months later, and if no further action has been taken it is possible that their elective operation will be cancelled.

Definition of anaemia:

• Hb <130g/L in males
• Hb <120g/L in females

Definition of iron deficiency:

• Ferritin <30ug/L and CRP normal; or
• Ferritin <100ug/L with elevated CRP.

These definitions are based on international guidelines of iron deficiency. Ferritin is elevated in inflammation, infection, liver disease and malignancy.  This can result in misleadingly elevated ferritin levels in iron-deficient patients with coexisting systemic illness.

Optimising iron stores prior to elective surgery where projected blood loss is high (e.g. joint replacement) leads to substantially lower patient morbidity and mortality.

1. Consider investigations as appropriate, such as:
   
   
   • The underlying cause of iron deficiency should be investigated in conjunction with treatment.
   • Consider gender, age, family history and presence of menstruation.
   • Determine cause and need for GI investigations.
   • Remember that ferritin may be elevated in the setting of inflammation, but iron deficiency may still be present.
   • Consider giving iron where ferritin is <100ug/L and there is a raised CRP.
   • We recognise that for some cases of chronic anaemia, a cause may not be found, and it is possible that surgery may proceed under certain circumstances.  In these circumstances, please send a letter of explanation to the pre-assessment clinic at Tauranga Hospital for an anaesthetist to review.

2. Give oral iron for 6 weeks:

   • Give oral iron unless contraindicated or not tolerated, usually ferrous fumarate (external link). Taking one tablet on alternative days leads to better compliance and absorption.
   • Provide a patient information leaflet (external link) which shows how to take the medication and what to do about other medications that may impact iron absorption.
   • Give IV iron infusion if oral iron contraindicated or not tolerated. Do not give IM iron.
   • Optimising iron stores prior to elective surgery where projected blood loss is high (egjoint replacement) leads to substantially lower patient morbidity and mortality.

3. Iron infusion if indicated:

   • Give IV iron infusion if oral iron contraindicated or not tolerated. Do not give IM iron.
   • Ferric carboxymaltose (Ferinject) (external link) is Pharmac funded with a special authority if ferritin is <20ug/L or approved by specialist, e.g. anaesthetist.
   • If unable to provide iron infusion in the community, please send a BPAC ereferral to General Medicine and note ‘For Iron Infusion’ in the subject line.

4. Repeat FBC ferritin and CRP.

5. If investigations complete or not needed and bloods normalised, patient to notify pre-assessment clinic (PAC):

   • On completion of investigations and treatment, please ask the patient to notify the PAC.
   • The contact details are on their letter from PAC:
     • Phone: 07 579 8260
     • Email: tga.preassessment@bopdhb.govt.nz 

6. If patient remains anaemic or iron deficient:

   • Arrange iron infusion and consider specialist referral:
     • Give IV iron infusion if oral iron contraindicated or not tolerated. Do not give IM iron.
     • Ferric carboxymaltose (Ferinject) (external link) is Pharmac funded with a special authority if ferritin is <20ug/L or approved by specialist, e.g. anaesthetist.
     • If unable to provide iron infusion in the community, please send a BPAC ereferral to General Medicine and note ‘For iron infusion’ in the subject line.
     • Consider referral to a specialist team as appropriate (e.g. gastroenterology, general medicine or gynaecology).
     • If anaemia persists despite adequate iron replacement, a haematology referral may be appropriate.
   • Patient to notify PAC:
     • On completion of investigations and treatment, please ask the patient to notify the PAC..
     • The contact details are on their letter from PAC:
       • Phone: 07 579 8260
       • Email: tga.preassessment@bopdhb.govt.nz 

Investigate cause

• Consider alternative causes of anaemia:
  • thalassaemia and other haemoglobinopathies
  • anaemia of chronic disease
  • haemolytic anaemia
  • B12 deficiency
  • folate deficiency
  • other
• Ferritin may be elevated in the setting of inflammation.
• However, iron deficiency may still be present.
• Consider giving iron where ferritin is <100ug/L and there is either a raised CRP or transfer in saturation is <20%.
• Suggested investigations:
  • Renal function, MCV/MCH and blood film
  • Check B12/folate levels and reticulocyte count
  • Check liver and thyroid function
  • Check serum protein electrophoresis

• If cause found

  • Optimise Hb by treating cause
  • Patient to Notify Pre-Assessment Clinic
    • On completion of investigations and treatment, please ask the patient to notify the PAC.
    • The contact details are on their letter from PAC: 
      • Phone: 07 579 8260
      • Email: tga.preassessment@bopdhb.govt.nz

• If cause not found

  • Consider specialist referral:
    • Seek haematology advice, especially if Hb <100g/L, there are additional cytopenias or a progressive unexplained anaemia.
    • In the presence of chronic kidney disease, seek renal advice.
    • We recognise that for some cases of chronic anaemia, a cause may not be found, and it is possible that surgery may proceed under certain circumstances. In these circumstances, please send a letter of explanation to the pre-assessment clinic at Tauranga Hospital (fax 07 571 0132) for an anaesthetist to review.
  • Patient to notify pre-assessment clinic:
    • On completion of investigations and treatment, please ask the patient to notify the PAC.
    • The contact details are on their letter from PAC:
      • Phone: 07 579 8260
      • Email: tga.preassessment@bopdhb.govt.nz

This pathway demonstrates the approach to uncontrolled diabetes if detected at pre-assessment. The pre-assessment team give the patient a letter to present to their GP indicating that the HbA1c requires optimisation. The patient will be contacted by pre-assessment six months later, and if no further action has been taken it is possible that their elective operation will be cancelled.

Definition

HbA1c ≥ 69mmol/mol:

• procedure on hold
• pre-operative optimisation required.

1. Optimise if possible in general practice.
2. If Hba1c < 69mmol/mol:
   • Patient to notify pre-assessment clinic (PAC).
     • On completion of treatment, please ask the patient to notify PAC.
     • The contact details are on their letter from PAC: 
       • Phone: 07 579 8260
       • Email: tga.preassessment@bopdhb.govt.nz
3. If Hba1c ≥ 69mmol/mol
   • Consider specialist referral.
   • Patient to notify PAC
     • On completion of treatment, please ask the patient to notify PAC.
     • The contact details are on their letter from PAC:
       • Phone: 07 579 8260
       • Email: tga.preassessment@bopdhb.govt.nz

This pathway demonstrates the approach to hypertension if detected at pre-assessment. The pre-assessment team will give the patient a letter to present to their GP indicating that hypertension is present and requires optimisation. The patient will be contacted by pre-assessment six months later, and if no further action has been taken it is possible that their elective operation will be cancelled.

Definition

• BP > 160/100mmHg
  • letter to GP for information
• BP > 180/110mmHg
  • procedure on hold
  • pre-operative optimisation required

1. Check BP in general practice and optimise if possible.

2. If serial measurements <170/100mmHg:

   • Three consecutive blood pressure readings of <170/100mmHg are required before elective surgery can proceed.
   • Please sign and stamp each blood pressure reading on the patient’s pre-assessment clinic (PAC) letter.
   • These can later be emailed to the PAC.
   • Patient to notify PAC and GP to email BP's
     • On completion of investigations and treatment, please can the GP send results (each entry signed and stamped by the GP) by email to PAC:
       • Email: tga.preassessment@bopdhb.govt.nz
     • Please then ask the patient to notify the PAC that this has been done.
     • The contact details are on their letter from PAC.
       • Phone: 07 557 5381
       • Email: tga.preassessment@bopdhb.govt.nz

3. If serial measurements ≥170/100mmHg:

   • Three consecutive blood pressure readings of <170/100mmHg are required before elective surgery can proceed.
   • Please sign and stamp each blood pressure reading on the patient’s PAC letter.
   • These can later be emailed to the PAC.
   • Consider specialist referral:
     • If blood pressure remains uncontrolled with optimal or maximum tolerated doses of four antihypertensive medications, consider expert advice if it has not already been obtained.
     • The first-line classes of antihypertensive drugs to use should be ACE inhibitors or (not and) angiotensin receptor blockers, calcium channel blockers and thiazide-like diuretics (preferably indapamide or chlorthalidone). Beta blockers can be used if other indications exist concurrently, e.g., heart failure, atrial fibrillation, or recent myocardial infarction.
   • Patient to notify pre-assessment clinic and GP to email BPs:
   • On completion of investigations and treatment, please can the GP send the blood pressure results (each entry signed and stamped by the GP) by email to the pre-assessment:
     • Email: tga.preassessment@bopdhb.govt.nz.
   • Please then ask the patient to notify the PAC that this has been done.
   • The contact details are on their letter from PAC.
     • Phone: 07 557 5381 
     • Email: tga.preassessment@bopdhb.govt.nz

This pathway demonstrates the approach to hyponatraemia if detected at pre-assessment. The pre-assessment team will give the patient a letter to present to their GP indicating that hyponatraemia is present and further action is required. The patient will be contacted by pre-assessment six months later, and if no further action has been taken it is possible that their elective operation will be cancelled.

Pre-operative hyponatraemia definition:

• Sodium < 132mmol/L
• Procedure on hold
• Pre-operative optimisation required

Management

1. Optimise if possible in general practice
2. If sodium ≥ 132mmol/L
   
   • Patient to notify pre-assessment clinic (PAC).
     
     • On completion of investigations and treatment, please ask the patient to notify PAC.
     • The contact details are on their letter from PAC.
       • phone: 07 579 8260
       • email: tga.preassessment@bopdhb.govt.nz
3. If sodium < 132mmol/L
   • Consider investigation and discuss with a physician
     • Lower sodium levels will be accepted if chronically low, investigated and discussed with a physician.
   • GP to notify the pre-assessment clinic
     • Please send details of historic figures if chronically low, relevant investigations performed and details of specialist discussion.