Management of a patient with diabetes who needs surgery or a procedure that requires fasting

See also: Diabetes Mellitus and Endoscopy

The major aims are to prevent hypoglycaemia during and after surgery and acute hyperglycaemia +/- ketosis after surgery.

Elective surgery should be planned in advance in consultation with the endocrinology team.  During the admission, the endocrinology team will oversee the peri-operative management of diabetes.  If the patient is admitted within usual working hours the diabetes team will prescribe the insulin doses; otherwise doses and management can be discussed with the Endocrinologist / fellow on call.

Peri-operative management of diabetes will be influenced by:

1. Duration of procedure / period of fasting

• 'Major': GA of >2 hours or prolonged period of fasting anticipated in the post-operative period
• 'Minor': GA of <2 hours duration; anticipated to resume oral intake prior to discharge on the same day

2. Current diabetes regimen

3. Time of surgery

4. Urgency of surgery

Categories discussed in this guideline include:

A. Elective surgery of a minor nature (GA <2 hours; short post-op fasting period)

B. Elective major surgery (GA >2hours or prolonged post-op fasting anticipated) 

C. Emergency surgery

A. Elective surgery of minor nature

• Aim for morning surgery and for the child with diabetes to be first on the surgical list.
• It is preferable to have child admitted the day before surgery.  If this is thought not to be possible, the endocrinology team must be informed as soon as possible in advance. A decision can then be made as to the safety / appropriateness of a same-day admission or the need to reschedule the procedure.
• Pre-op management will vary, depending on the patient's usual insulin regimen

(i) twice daily insulin regimen

(ii) multiple daily injections (basal-bolus)

(iii) insulin pump therapy

(i) Elective minor surgery for patients on twice daily insulin regimens:

• The child can eat and drink normally before going to bed; however evening insulin dose should be adjusted as follows:
• Prior to their evening meal on the night before the procedure the child should receive:
  • Their full usual dose of short-acting insulin, along with 
  • 75% of their usual long acting insulin dose
  • For example if a child usually has 12 units of levemir and 4 units of novorapid in the evening, the dose to be given prior to the procedure would be 9 units of levemir and 4 units of novorapid

• Monitor blood glucose level (BGL) before bed; monitor ketones (using bedside testing on Optium meter) if BGL is >15.0 mmol/L.  If ketones are ?1.0, discuss need for additional insulin with endocrinologist / fellow on call.

If surgery is in the morning

• 2 1/2 hours before surgery (~6.00 a.m.) a BGL should be performed. If BGL is below 8.0 mmol/L, the child should be given a drink of lemonade or other palatable sugar-containing clear fluid (10% sugar). The amount given should be between 5 and 10 mL/kg body weight with a maximum of 200 mL. A note should be made on the chart informing the Anaesthetist that this action has been taken. 
• Measure BGL hourly pre-op, including one just before leaving the ward. 

• 1/10th of the normal total daily insulin requirement should be given as short acting insulin on the morning before surgery (~7.30-8.00am).  This calculation should be rounded down to the nearest whole unit.
  
  For example, if the patient's normal insulin is 24 units Levemir and 5 units Actrapid in the morning plus 12 units Levemir and 4 units Novorapid in the evening:
  
  Total daily dose is 45 units / day, then 4 units of Actrapid is given. 

• It is preferable not to start intravenous fluids in the ward as this can be done when the child arrives in theatre.   However, if any BGL is <4.0 mmol/L within the 2 hours prior to surgery, an i.v line will need to be sited and 2-5 mL/kg of 10% dextrose given as an i.v bolus, before commencing dextrose-containing i.v. fluids (eg Plasma-Lyte 148 and 5% Glucose with 20 mmol/L KCl OR 0.9% sodium chloride (normal saline) and 5% Glucose with 20 mmol/L KCl) at the child's maintenance requirements
• BGL should be checked hourly intra- and post- operatively (including a level immediately prior to transfer to and from theatre) until tolerating oral intake. When tolerating oral intake, i.v. fluids can cease.   Check BGL 2-4 hrly thereafter
• The child will need a further dose of short acting insulin (~15-20% of total daily dose) before lunch. If unexpectedly not tolerating oral diet, give this additional insulin dose 4-6 hours after the morning dose and continue i.v. fluids.  Aim to keep BGL in the range 5 - 10 mmol/L
• In general patients will be discharged home in the afternoon after minor surgery.  Advice should be given to have their usual dose of insulin prior to evening meal

If surgery is in the afternoon

• On the morning of surgery at ~07.00am, 1/10th of normal total daily insulin dose should be given as short acting insulin before a light breakfast consisting of 2-3 carbohydrate serves
• Check BGL 2.5 hours before anticipated time of surgery. If the blood glucose is below 8.0 mmol/L a drink of lemonade should be given (5-10 mL/kg, up to 200 mL max as outlined above).  Inform the anaesthetist if this is necessary.  Intravenous fluids would not normally be started until the child arrives in theatre, unless hypoglycaemia occurs
• An additional injection of short acting insulin at 1/10^th of total daily dose is given at ~12.00 noon, without food as the patient will be fasting

• Thereafter, BGL should be checked hourly prior to, during and after surgery (including a level immediately prior to transfer to and from theatre) until tolerating oral intake. I.v. fluids can then cease.   Check BGL 2-4 hourly thereafter.

• If eating normally, the usual evening dose of insulin can be given. If unable to eat, a plan for ongoing insulin and i.v. fluids should be discussed with the endocrinology team.  

(ii) Elective minor surgery for patients on multiple daily injections of insulin (basal-bolus regimens):

• The majority of patients using basal-bolus regimens give their basal insulin (eg lantus) in the evening.  The usual dose of basal insulin can be given the night before, unless there is a recent pattern of overnight or early morning hypos, in which case the dose should be decreased by ~20%
• If the patient takes basal insulin in the morning, then they should have their full dose of basal insulin on the day before surgery and 80% of their usual basal insulin dose on the morning of surgery

If surgery is in the morning

• Check BGLs before bed, and at ~06.00am, with bedside ketones test if any BGL is >15.0 mmol/L.  Inform the endocrinology team if ketones are ?1.0
• Short / rapid acting insulin is not needed before surgery as the background lantus dose will suffice.  Patients on this regimen therefore only need oral fluids if the BGL at 06.00am is <6.0 mmol/L, when lemonade (5-10 mL/kg; max 200 mL) can be given.  Inform the anaesthetist if this is necessary
• Check BGLs hourly including one just before leaving the ward.  Within the 2 hours prior to surgery, if any BGL is <4.0mmol/l, an i.v. line will need to be sited and 2-5 mL/kg of 10% dextrose given as an i.v. bolus before commencing glucose containing i.v. fluids (eg Plasma-Lyte 148 and 5% Glucose with KCl OR 0.9% sodium chloride (normal saline) and 5% Glucose with KCl)
• BGL should be checked hourly intra- and post- operatively (including a level immediately prior to transfer back to the ward) until tolerating oral intake
• Once tolerating oral diet, the patient can have their usual rapid-acting insulin dose before a meal consisting of their usual carbohydrate serves.  I.V. fluids can then cease 
• Thereafter, the patient can be advised to resume their usual insulin dosing and BGL monitoring regimen  
  

If surgery is in the afternoon

• Basal insulin will be given as outlined above (either full basal dose the night before unless recent history of hypos, or 80% of usual dose if basal insulin is given in the morning)
• Give 80% of usual rapid-acting insulin with breakfast containing the patient's usual number of carbohydrate serves
• Check BGL 2.5 hours prior to surgery and give clear sugar-containing fluids (5-10 mL/kg, up to 200 mL max) if BGL is <6.0 mmol/L
• Check BGLs hourly including a level just before leaving the ward.  Within the 2 hours prior to surgery, if any BGL is <4.0mmol/l, an i.v. line will need to be sited and 2-5ml/kg of 10% dextrose given as an i.v. bolus before commencing glucose containing i.v. fluids (eg Plasma-Lyte 148 and 5% Glucose OR 0.9% sodium chloride (normal saline) and 5% Glucose with KCl)
• BGL should be checked hourly intra- and post- operatively (including a level immediately prior to transfer back to the ward) until tolerating oral intake
• Once tolerating oral diet, the patient can have their usual rapid-acting insulin dose before a meal consisting of their usual carbohydrate serves.  I.V. fluids can then cease 
• Thereafter, the patient can be advised to resume their usual insulin dosing and BGL monitoring regimen 

(iii) Elective minor surgery for patients on insulin pump therapy / continuous subcutaneous insulin infusion (CSII):

Please note that insulin pumps can NOT be worn for procedures that involve screening / exposure to radiation (eg cardiac catheterisation).  Please discuss such cases and a plan for insulin delivery with the endocrinology team in advance of any such procedures.

For all other minor elective procedures / surgery:

• The patient should be advised to change the subcutaneous infusion site on the day before surgery.  This should be done in time to have at least 2 subsequent BGL checks on that day that indicate the line is working well

If surgery is in the morning

• Patient can eat and drink normally administering insulin according to their individual pump settings until midnight the night before
• Continue insulin administration using the patient's usual basal infusion rates overnight
• Check BGL at 06.00am 
  • If BGL is <4.0 mmol/L, give 5-10 mL/kg (up to a max of 200 mL) of sugar-containing clear fluids (eg lemonade) and commence a temporary basal rate of 70% of usual for 4 hours.  Recheck BGL after 30 minutes to ensure response to the lemonade 
  • If BGL is between 4.0 and 10.0 mmol/L, commence a temporary basal rate of 70% of their usual rate for 4 hours
  • If BGL at 06.00am is >10.0 mmol/L, program the BGL into the pump and give the recommended correction dose of insulin. A temporary reduction in basal to 70% of usual should also be commenced for 4 hours
• Check BGL hourly and just before leaving the ward in all cases
• Within the 2 hours prior to surgery
  • if any BGL is <4.0 mmol/L, an i.v. line will need to be sited and 2-5 mL/kg of 10% dextrose given as an i.v. bolus before commencing glucose containing i.v. fluids (eg Plasma-Lyte 148 and 5% Glucose with KCl OR 0.9% sodium chloride (normal saline) and 5% Glucose with KCl)
  • if BGL rises to >10 mmol/L, the temporary reduction in basal rate can be discontinued as a first measure.  In this instance, a correction bolus of insulin will only be given if BGL continues to rise at subsequent hourly checks.  Please discuss such cases with the endocrinology team
  • If any BGL is >15.0 mmol/L, check ketones. If result is ?1.0, discuss with endocrinology team
• The subcutaneous infusion site should be secured tightly prior to going to theatre to prevent dislodgement and interruption to insulin delivery intra-operatively
• CSII can be continued during the surgery / procedure using the basal rate as programmed above 
• Check BGLs hourly intra-operatively 
  • If BGL drops below 4.0mmol/l administer 2-5 mL/kg 10% dextrose as an i.v. bolus and commence dextrose containing iv fluids (or increase the dextrose concentration of fluids running) 
  • If any BGL is >15.0, check ketones.  Inform endocrinology team if ketones are ?1.0 as additional insulin given by subcutaneous injection may be required
• In recovery, check BGL
  • If >10.0 mmol/L, enter the BGL into the pump and administer the recommended correction dose of insulin (the child's parents can assist with this)
  • If between 4.0 and 10.0 mmol/L continue with programmed basal rates
  • If <4.0mmol/l treat with 2-5 mL/kg 10% dextrose given as an i.v. bolus and increase the dextrose concentration of i.v. maintenance fluids
• Once patient is able to eat or drink, i.v. fluids can be discontinued and they can recommence pre-meal or pre-snack insulin administration using their usual pump settings

If surgery is in the afternoon:

• Procedure is very similar to that followed above for morning surgery, except patient can eat a light breakfast.  A pre-breakfast BGL should be entered into the pump and pre-meal insulin administered as per their usual pump settings
• Check BGL 2.5 hours prior to planned time of surgery and follow the guidelines as outlined for 06.00am BGL check in CSII patients having morning surgery above.  BGLs should be checked hourly thereafter, and immediately prior to transfer to and from theatre, as outlined above
• Intra- and post-operative management is as outlined above for patients having morning surgery
  

B. For elective major surgery

• The child should be admitted the day before and ideally surgery should take place on a morning list
• An i.v. line should be sited on the day of admission
• The child can eat normally and have their usual subcutaneous insulin the evening before the procedure.  If the child is on an insulin pump, this can be continued overnight at the usual rates.  BGLs should be checked routinely before bed and at ~02.00am and 06.00am 
• At ~06.00am an intravenous insulin infusion and maintenance intravenous fluids (0.9% sodium chloride (normal saline) and 5% Glucose with 20 mmol/L KCl) should be commenced 
  • The insulin infusion is made up by adding 50 units of regular insulin (Actrapid or Humulin R) to 49.5 ml 0.9% NaCl (1 unit/ml solution)
  • The insulin infusion may be run as a sideline with the maintenance fluids via a three-way tap, provided a syringe pump is used. Ensure that the insulin is clearly labelled
  • The initial rate of the insulin infusion should be 0.02 - 0.03 U/kg/hr (note that this maintenance rate is much lower than the rate required to treat DKA).  Start with 0.02 U/kg/hr if BGL is ?10.0 mmol/L; 0.03 U/kg/hr if BGL >10.0 mmol/L
• If the patient is usually managed with insulin pump therapy, subcutaneous insulin via the pump should be discontinued half an hour after i.v. insulin and i.v. fluids are commence
• BGLs should be monitored hourly while on an insulin infusion
  • Aim to keep BGLs between 5.0 and 10.0 mmol/L 
  • If 2 consecutive hourly BGLs are above 10.0 mmol/L, the insulin infusion rate should be increased by 0.005-0.01 U/kg/hr 
  • If any BGL is >15.0 mmol/L, check blood ketones with a bedside test (Optium^TM meter).  Discuss ketones ?1.0 with endocrinology team
  • If any BGL is <5.0 mmol/L, the insulin rate can be decreased by the same increment (0.005-0.01U/kg/hr) to prevent hypoglycaemia. If the insulin rate is already at 0.02U/kg/hr, increase the dextrose concentration of i.v. fluids to 10%
• Transition back to subcutaneous insulin in the post-op period should be discussed on an individual basis with the diabetes team; this will vary depending on the patient's usual insulin regimen and ability to tolerate oral diet.  It is possible to recommence CSII in the post-operative period even if the patient is being kept nil by mouth; this should be done by the endocrinology team who will recommend rates and settings on an individual basis
• In rare cases where patients are unable to have food / enteral nutrition for prolonged periods post-operatively (eg >2 days), it may be possible to decrease the frequency of BGL testing (to less frequently than hourly).  This should only be done if approved by the endocrinologist on call
  

C. For emergency surgery

• The Endocrinology team / consultant on call should be contacted about all patients with diabetes who require emergency surgery
• In preparation for emergency surgery, the child should first be assessed clinically and biochemically (blood gas including glucose and bedside ketones test, along with U&E, FBE and other pre-op bloods as required)
• If ketoacidosis is present, treatment according to the diabetic ketoacidosis protocol should be commenced immediately and the patient's circulating volume and electrolytes stabilised before surgery
• Where DKA is present, initial insulin infusion rates will be 0.1 U/kg/hr (or 0.05 U/kg/hr in a child ?2 years)
• This rate should be continued until ketones have cleared and acidosis has corrected (see DKA protocol)
• Once ketones have cleared and acidosis has corrected, the insulin infusion rates may be reduced and the dextrose concentration of i.v. fluids adjusted as appropriate to maintain BGLs between 5-10 mmol/L.  Maintenance insulin infusion rates once ketosis/acidosis has fully cleared are usually in the range of 0.02-0.03 U/kg/hr; the endocrinology team will advise on this
• If there is no ketoacidosis, the child should be fasted and commenced on intravenous dextrose/saline (start with 0.9% sodium chloride (normal saline) and 5% Glucose with 20mmol/l KCl) along with continuous IV insulin infusion 
• The insulin infusion is made up by adding 50 units of regular insulin (Actrapid HM or Humulin R) to 49.5 mL 0.9% NaCl (1 unit/ml solution)
• The insulin infusion may be run as a sideline with the maintenance fluids via a three-way tap, provided a syringe pump is used. Ensure that the insulin is clearly labelled
• The initial rate of the insulin infusion should be 0.02 - 0.03 U/kg/hr (note that this maintenance rate is much lower than the rate required to treat DKA).  Start with 0.02 U/kg/hr if BGL is ?10.0mmol/l; 0.03U/kg/hr if BGL >10.0 mmol/L
• If the patient is usually managed with insulin pump therapy, subcutaneous insulin via the pump should be discontinued half an hour after i.v. insulin and i.v. fluids are commenced 
• BGLs should be monitored hourly while on an insulin infusion
  • Aim to keep BGLs between 5.0 and 10.0 mmol/L
  • If 2 consecutive hourly BGLs are above 10.0 mmol/L, the insulin infusion rate should be increased by 0.005-0.01 U/kg/hr
  • If any BGL is >15.0 mmol/L, check blood ketones with a bedside test (Optium^TM meter).  Discuss ketones ?1.0 with endocrinology team
  • If any BGL is <5.0 mmol/L, the insulin rate can be decreased by the same increment (0.005-0.01 U/kg/hr) to prevent hypoglycaemia. If the insulin rate is already at 0.02 U/kg/hr, increase the dextrose concentration of i.v. fluids to 10%
• Transition back to subcutaneous insulin in the post-op period should be discussed on an individual basis with the diabetes team; this will vary depending on the patient's usual insulin regimen and ability to tolerate oral diet.  It is possible to recommence CSII in the post-operative period even if the patient is being kept nil by mouth; this should be done by the endocrinology team who will recommend rates and settings on an individual basis
• In rare cases where patients are unable to have food / enteral nutrition for prolonged periods post-operatively (eg >2 days), it may be possible to decrease the frequency of BGL testing once a stable state has been reached in the post op period.  The endocrinology team will advise on this on an individual basis