DT Peri-operative management of the surgical patient with diabetes GL059 Approval Approval Group Job Title, Chair of Committee Date Anaesthetics Clinical Governance Chair Anaesthetic governance Nov 2016 Change History Version Date Author, job title Reason 7 Apr 2016 J Rechner, A Pal 7.1 Nov 2016 J Rechner, A Pal Consultant Anaesthetist, Endocrine Consultant Consultant Anaesthetist, Endocrine Consultant Update and review Review, no changes Job Title: Consultant Anaesthetist, Endocrine Consultant Review Date: Nov 2018 Location: Corporate governance shared drive GL059
Contents 1. Purpose 2. Introduction 3. Scope 4. Referring primary care physician 5. Surgical department 6. Pre-operative assessment 7. Management of existing therapy 8. Intra-operative care and monitoring 9. Fluid management 10. Variable rate intravenous insulin infusion 11. Returning to pre-operative medication and diet 12. Patients with diabetes requiring emergency surgery 1. Purpose The purpose of this clinical guideline is to describe the peri-operative management of the surgical patient with diabetes. 2. Introduction The Joint British Diabetes Societies produced guidance in 2011 relating to the management of adults with diabetes undergoing surgery and elective procedures. This was revised in September 2015 with considerably greater focus given to maintaining good glucose control in the perioperative period as there is now good data to show that poor glucose control peri-operatively is associated with an increased risk of all the complication of surgery as well as an increased length of hospital stay. The Association of Anaesthetists of Great Britain and Ireland subsequently published guidance in September 2015 which mirrors the JBDS guidance. Diabetes affects 10-15% of the surgical population, and, as the number of people with diabetes continues to rise (by up to 50% in the next decade), so too will the number of patients requiring surgery with diabetes continue to rise. Perioperative mortality rates are up to 50% greater than in the non-diabetic population with a two to three fold increase in complications such as respiratory infections, surgical site infections, myocardial infarction and acute kidney injury. In order to reduce perioperative complications it is important that diabetes be as well controlled as possible before elective surgery, with a HbA1c of <69 mmol/mol for elective cases. 2
3. Scope This clinical guideline applies to all health professionals involved in the management of the surgical patient with diabetes. This includes the referring primary care physician and health professionals in the secondary care setting involved in perioperative management of surgical patients. 4. Referring Primary Care Physician Glycaemic control should be checked at the time of referral for surgery. Information about duration, type of diabetes, current treatment and complications should be made available to the secondary care team. If the HbA1c is greater than 69mmol/mol, every effort should be made to improve control. For frail elderly patients, or patients with multiple co-morbidities at risk of hypoglycaemia, a higher upper limit of 75 mmol/mol may be appropriate. For patients currently under a secondary care team, the referring primary care physician should communicate directly with this team for advice. For patients managed in the community, the referring primary care physician can refer/communicate with: a community endocrinology consultant, community diabetic specialist nurse or secondary care physician, if required. This information should be included in the referral for surgery. 5. Surgical Department. Referrals to surgical departments for elective surgery may not be accepted if the above criteria are not met. 6. Pre-operative assessment Patients with diabetes attending pre-operative assessment clinics should have their Hba1c checked if not done so within the previous month. Patients with diabetes should be provided with verbal and written information about diabetes in the peri-operative period. If the HbA1c is >69 mmol/mol, and a specialist opinion, as defined above, has not been sought, elective surgery should be delayed while control is improved. Surgical procedures which are 3
urgent (or involve additional risks if delayed) should not be postponed without further discussion with the surgeon. For frail elderly patients, or patients with multiple comorbidities, at risk of hypoglycaemia, a higher upper limit of 75 mmol/mol may be appropriate. All patients with a HbA1c >69mmol/mol should receive written information advising them of the increased risks of surgery and providing advice on improving diabetic control. Patients who are being discharged back to their GP should receive written information asking them to attend their GP. A referral to a diabetes specialist, as defined above, may be warranted. The patient should be advised to attend their GP surgery at three months for a repeat HbA1c (fructosamine is also acceptable). If the HbA1c at three months is less than 69mmol/mol (fructosamine less 345 µmol ), the GP or patient can contact the operating surgeon and be listed for surgery. If the HbA1c remains high, the GP should make an active decision with the patient that all possible avenues for improvement have been explored and should communicate this, along with any interventions/referrals, to the anaesthetic department. As different surgical procedures carry different risks, the decision to proceed with poorly controlled diabetes will lie with the surgeon and anaesthetist. Patients undergoing procedures, for whom delaying surgery may incur other complications (such as laparascopic cholecystectomies), with a HbA1c greater than 69mmol/mol, will require the anaesthetist to communicate with the operating surgeon in order to agree an acceptable time frame for optimisation. If time allows, an internal referral to the diabetes team is indicated. Please fax a referral to CAT 9 on 7678. Patients undergoing urgent surgery, with a HbA1c greater than 69mmol/mol, should be referred internally to the diabetes team by fax to CAT 9 on 7678 or discussed with the on call diabetes registrar on bleep 199/192. The patient may need to be admitted the night before for a variable rate intravenous insulin infusion (VRIII) if on the morning list, or first thing in the morning if on an afternoon list. In a small number of cases, following discussion with a diabetes specialist, it may not be possible to improve diabetic control. In these circumstances the patient should be made aware of the increased risks. These patients may need to be admitted earlier than normal in case they require a variable rate intravenous insulin infusion (VRIII). Pre-operative tests to assess co-morbidities should be ordered in line with NICE guidance. Random blood glucose is no longer indicated. Patients should be first on the operating list to minimise the period of fasting. 4
Patients should be provided with written instructions about management of their diabetes medication on the day of surgery and management of hypo- or hyperglycaemia in the perioperative period. Patients should be advised to carry a form of glucose in case of symptoms of hypoglycaemia; this should be a clear fluid or suitable alternative. 7. Management of existing therapy Patients should be allowed to retain control and possession of, and continue to self-administer, their medication. Patients on continuous subcutaneous insulin pumps (CSII) are very well educated and will be able to self-manage their diabetes appropriately if given the opportunity to do so. If the starvation period is short, pump therapy should be continued and patients should remain on their basal rate until they are eating and normally. If more than one meal is missed, the pump should be removed and a VRIII used. Significant hyperkalaemia may occur after discontinuation of an insulin pump. CBG and electrolytes should be checked and hypoglycaemia treated in the normal way. Insulin-Short starvation time-no more than one missed meal 5
Insulin Once daily (Lantus, Levemir, Tresiba, Insulatard, Humulin I, Insuman) Twice daily Biphasic or ultra-long acting (Novomix 30, Humulin M3, Humalog Mix 25, Humalog Mix 50, Insuman Comb 25, Insuman Comb 50, Levemir, Lantus) Day before admission Reduce dose by 20% No dose change AM list Day of surgery PM list On VRIII Reduce dose by 20% Reduce dose by 20% Halve the usual morning dose. Leave evening dose unchanged Stop until eating and Short-acting (animal neutral, novorapid, Humulin S Apidra) and Intermediate-acting (animal isophane, insulatard, Humulin I, Insuman) No dose change Calculate total morning dose of insulin; give half as intermediate-acting only. Evening dose unchanged Stop until eating and Three to five injections daily No dose change Basal bolus regime: Omit morning and lunchtime short-acting insulins; keep basal unchanged Premixed AM insulin: Halve morning dose and omit lunch time dose Give usual morning insulin. Omit lunch time dose Stop until eating and Oral hypoglycaemic agents-short starvation time-no more than one missed meal 6
Agent Day before admission Day of surgery AM list PM list On VRIII Drugs that require omission when fasting owing to risk of hypoglycaemia Meglitinides (repaglinide, nateglinide) Sulphonylureas (glibenclamide, gliclazide, glipizide) Take as normal Omit AM dose Give AM dose if eating Stop until eating and Take as normal Omit AM dose Stop until eating and Drugs that require omission when fasting owing to risk of ketoacidosis SGLT-2 inhibitors (dapagliflozin, canagliflozin) Take as normal Drugs that may be continued when fasting Halve the morning dose; normal evening dose Stop until eating and Acarbose Take as normal Take as normal Stop until eating and DPP-IV inhibitors (sitagliptin, vildagliptin, saxagliptin, alogliptin, linagliptin) GLP-1 analogues (exenatide, liraglutide, lixisenatide) Take as normal Take as normal Stop until eating and Take as normal Take as normal Take as normal Pioglitazone Take as normal Take as normal Stop until eating and Metformin* Take as normal Take as normal Stop until eating and *Metformin. Omit on morning of procedure and for the following 48 hrs if contrast medium is to be used or the egfr is less than 60 ml/min.1.73/m 2 8. Intra-operative care and monitoring The aim of intra-operative care is to maintain good glycaemic control and normal electrolyte concentrations. An intra-operative CBG range of 6 10 mmol/l should be aimed for (an upper limit of 12 mmol/l may be tolerated at times). The CBG should be checked before induction of anaesthesia and monitored regularly during the 7
procedure (at least hourly, or more frequently if the results are outside the target range). The CBG, insulin infusion rate and substrate infusion should be recorded on the anaesthetic record. Management of intra-operative hyperglycaemia and hypoglycaemia If the CBG exceeds 12 mmol/l and insulin has been omitted, capillary blood ketone levels should be measured. If the capillary blood ketones are > 3 mmol/l or there is significant ketonuria (> 2+ on urine sticks) the patient should be treated as having diabetic ketoacidosis (DKA). Diabetic ketoacidosis is a medical emergency and specialist help should be obtained from the diabetes team. Please contact the diabetes registrar on bleep 199/192. If DKA is not present, the high blood glucose should be corrected using subcutaneous insulin or by altering the rate of the VRIII (if in use). If two subcutaneous insulin doses do not work, a VRIII should be started. Insulin doses should be written in full, avoiding abbreviations of the words units. 1) Treatment of hyperglycaemia in a patient with Type-1 diabetes Subcutaneous rapid-acting insulin (such as Novorapid) should be given (up to a maximum of 6 units), assuming that 1 unit will drop the CBG by 3 mmol/l. If the patient is awake, it is important to ensure that the patient is content with proposed dose (patients may react differently to subcutaneous rapid-acting insulin). The CBG should be checked hourly and a second dose considered only after 2 hrs. 2) Treatment of hyperglycaemia in a patient with Type-2 diabetes (including those on insulin) Subcutaneous rapid-acting insulin (such as Novorapid) 0.1 unit/kgshould be given (up to a maximum of 6 units). The CBG should be checked hourly and a second dose considered only after 2 h. A VRIII should be considered if the patient remains hyperglycaemic. 3) Treatment of intra-operative hypoglycaemia For a CBG 4.0 6.0 mmol/l, 50 ml of glucose 20% (10 g) should be given intravenously; for hypoglycaemia < 4.0 mmol/la dose of 100 ml of glucose 20% (20 g) should be given. 9. Fluid management 8
It is now recognised that Plasmalyte solution is safe to administer to patients. The initial fluid management for patients requiring a VRIII should be glucose 5% in saline 0.45% pre-mixed with either potassium chloride 0.15% (20 mmol/l) or potassium chloride 0.3% (40 mmol/l), depending on the presence of hypokalaemia (< 3.5 mmol/l). Currently only the former is available in 500ml bags in this Trust. Fluid should be administered at the rate that is appropriate for the patient s usual maintenance requirements usually 25 50 ml/kg/day (approximately 83 ml/h for a 70-kg patient). Electrolytes should be checked daily in patients on a VRIII 10. Variable rate intravenous insulin infusion A VRIII should be avoided if possible but is the preferred option in: patients who will miss more than one meal; patients with Type 1 diabetes who have not received background insulin; patients with poorly controlled diabetes and most patients with diabetes requiring emergency surgery. Please refer to the Guideline for safe administration of the VRIII for adult in-patients with diabetes (CG242). 50 units of Actrapid is mixed with 50ml 0.9% sodium chloride and administered intravenously though an extension set with a Y connector for simultaneous administration of glucose 5% in saline 0.45% with potassium chloride 0.15%. There should be an anti-syphon valve on the insulin line and an anti-reflux valve on the dextrose saline line. Rate of VRIII: Blood glucose mmol/l Regimen A Units/hr Regimen B Units/hr 0-4 Stop and treat hypo Stop and treat hypo 4.1-6.0 1 1 6.1-8.0 2 3 8.1-10.0 3 4 Over 10 4 6 If CBG remains above 10mmol/L for 4 hours move to regimen B. For patients already on insulin treatment in excess of 100 units in 24hrs start on regimen B. If CBG remains above 10mmol/L for 4 hours on regimen B please contact the Diabetes Specialist team on bleep 199 or 192. Out of hours, it is reasonable for a suitably experienced doctor to either increase the units of insulin per hour or decrease the rate of infusion of glucose 5% in saline 0.45% with potassium chloride 0.15%. Unopposed intravenous infusion of insulin on the ward is not recommended. 9
11. Returning to pre-operative medication and diet The postoperative blood glucose management plan, and any alterations to existing medications, should be clearly communicated to ward staff. If the patient has type-1 diabetes and a VRIII has been used, it must be continued for 30 60 min after the patient has had their subcutaneous insulin. Premature discontinuation is associated with iatrogenic DKA. Oral hypoglycaemic agents should be recommenced at pre-operative doses once the patient is ready to eat and drink; withholding or reduction in sulphonylureas may be required if the food intake is likely to be reduced. Metformin should only be restarted if the estimated glomerular filtration rate exceeds 50 ml/min.1.73 m 2. Restarting subcutaneous insulin for patients already established on insulin should commence once the patient is able to eat and drink without nausea or vomiting. The pre-surgical regimen should be restarted, but may require adjustment because the insulin requirement may change as a result of postoperative stress, infection or altered food intake. The diabetes specialist team should be consulted if the blood glucose levels are outside the acceptable range (6 12 mmol/l) or if a change in diabetes management is required. The transition from intravenous to subcutaneous insulin should take place when the next mealrelated subcutaneous insulin dose is due, for example with breakfast or lunch. There should be an overlap between the end of the VRIII and the first injection of subcutaneous insulin, which should be given with a meal and the intravenous insulin and fluids discontinued 30-60 min later. If the patient was previously on a long-acting insulin analogue such as Lantus, Levemir or Tresbia, this should have been continued and thus the only action should be to restart his/her usual rapidacting insulin at the next meal as outlined above. If the basal insulin was stopped, the insulin infusion should be continued until a background insulin has been given. For the patient on a twice-daily, fixed-mix regimen, the insulin should be re-introduced before breakfast or before the evening meal, and not at any other time. The VRIII should be maintained for 30-60 min after the subcutaneous insulin has been given. For the patient on a continuous subcutaneous insulin infusion, the subcutaneous insulin infusion should be recommenced at the patient s normal basal rate; the VRIII should be continued until the 10
next meal bolus has been given. The subcutaneous insulin infusions should not be re-started at bedtime. 12. Patients with diabetes requiring emergency surgery A VRIII should be the default technique to manage a patient undergoing emergency surgery because of the unpredictability of the starvation period. Use of a fixed-rate intravenous insulin infusion. This should only be used if the patient requires immediate surgery and has concurrent DKA. Early involvement of the diabetes inpatient specialist team should be sought. The aim is for the patient to be taken to the operating theatre with a CBG of 6 10 mmol/l (6 12 mmol/l may be acceptable), without overt DKA, and having been adequately resuscitated. The CBG should be checked regularly (hourly as a minimum whilst acutely unwell),and a VRIII established using dextrose 5% in saline 0.45% with pre-mixed potassium chloride as the substrate. The patient should be checked for ketonaemia (> 3.0 mmol.l1) or significant ketonuria (> 2+ on urine sticks) if the CBG exceeds 12 mmol.l If possible, long-acting insulin (Levemir, Lantus, Tresiba) should be continued in all patients at 80% of the usual dose. 13. References 1. Association of Anaesthetists of Great Britain and Ireland Guideline: Peri-operative management of the surgical patient with diabetes September 2015 2. JBDS Guideline: Management of adults with diabetes undergoing surgery and elective procedures: Improving standards September 2015 3. Perioperative iv fluids in diabetic patients- don t forget the salt- Simpson, Levy, Hall Anaesthesia 2008, 1043-45 4. Day Surgery and the diabetic patient, - British Association of Day Surgery 2004 11