management of diabetes patients in surgery

8/3/2019 Management of Diabetes Patients in Surgery

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Management of

Diabetes in Surgery


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Diabetes

Diabetes is a metabolic disorder resultingfrom insulin deficiency or intolerance

Associated with acute and long term systemicproblems

Diagnosed by a random plasma glucose>11.1mmol/l and a fasting glucose>7.0mmol/l(WHO criteria)

The two most common forms of diabetes areInsulin Dependant Diabetes Mellitus (Type 1)and Non Insulin Dependant Diabetes Mellitus(Type 2)


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Type 1 Diabetes Mellitus

Polygenic disorder thought to be of auto immuneaetiology

Results in destruction of cells in the Islets of

Langerhans in the Pancreas, with subsequent insulin

deficiency

Young onset

0.4% prevalence

Endogenous insulin is required to maintain plasmaglucose levels to within physiological levels


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Type 2 Diabetes Mellitus

Hypoglycaemia resulting from reduced insulinsecretion and peripheral insulin resistance

Some genetic concordance

Older onset, associated with central obesity

Depending on severity, may be controlledwith:

diet and exercise to lose weight

oral hypoglycaemics

insulin


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Diabetes and Surgery

Surgery is a form of physical trauma

It results in catabolism, increased metabolic rate,increased fat and protein breakdown, glucose intoleranceand starvation.

In a diabetic patient, the pre existing metabolicdisturbances are exacerbated by surgery

The type of diabetes, amount of insulin dose, diet or oralhypoglycaemic agents must be considered as this willchange the overall management plan

The risk of significant end-organ damage increases withthe duration of diabetes, although the quality of glucosecontrol is more important than the absolute time


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Factors Adversely Affecting

Diabetic Control Perioperatively Anxiety

Starvation

Anaesthetic drugs

Infection

Metabolic response to trauma Diseases underlying need for surgery

Other drugs e.g. steroids


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Metabolic Responses to Surgery

Hormonal

Secretion of stresshormones

Cortisol

Catecholamines

Glucagon

Growth Hormone

Cytokines

Relative decrease ininsulin secretion

Peripheral insulinresistance

Metabolic

Increasedgluconeogenesisand glycogenolysis

Hyperglycaemia

Lipolysis

Protein breakdown


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Metabolic Response to Surgery

and Diabetes Hypoglycaemia May develop perioperatively due to the residual effects of

preoperative long acting oral hypoglycaemic agents orinsulin.

Exacerbated by preoperative fast or insufficient glucoseadministration

Counter-regulatory mechanisms may be defective becauseof autonomic dysfunction

Can lead to irreversible neurological deficits

Dangerous in anaesthetised or neuropathic patient as thewarning signs may be absent

Management

Give i.v dextrose and monitor glucose levels


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and Diabetes

Hyperglycaemia Glucagon, cortisol and adrenaline secretion as part of the

neuroendocrine response to trauma, combined withiatrogenic insulin deficiency or glucose overadministrationmay result in hyperglycaemia

Causes osmotic diuresis, making volume status difficult todetermine and risking profound dehydration and organhypoperfusion, and increased risk of UTI

osmotic diuresis, delayed wound healing, exacerbation ofbrain, spinal cord and renal damage by ischaemia

Results in hyperosmolality with hyperviscocity,thrombogenesis and cerebral oedema

Management

Frequently measure blood glucose and administer insulin


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and Diabetes Ketoacidosis

Any patient who is in a severe catabolic state and has aninsulin deficiency (absolute or relative) can decompensate

into keto-acidosis

Most common in type 1 patients

Increased risk postoperatively, often precipitated by thestress response, infection, MI, failure to continue insulin

therapy. characterised by hyperglycaemia, hyperosmolarity,

dehydration (may lead to shock and hypotension) andexcess ketone body production resulting in an anion gapmetabolic acidosis.


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and Diabetes Management

restore intravascular volume

eliminate ketonaemia

control blood glucose

replace electrolytes

monitor glucose and ketone levels

Mortality from DKA5-10%

Electrolyte abnormalities

Anticipate imbalances in potassium, magnesium and

phosphate


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Underlying Cardiac Complications

of Diabetes and Surgery Cardiovascular problems frequently present in long standing

diabetics

Ischaemic Heart Disease - Often silent ischaemia

Coronary artery disease

Hypertension

Diabetic patients must be considered as being at high risk of MI

Silent MI in autonomic neuropathy as Cardiac AutonomicNeuropathy may abolish the hearts response to stress

Induction of anaesthesia and tracheal intubation can lead to a

reduction in cardiac output


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Underlying Cardiac Complications

of Diabetes and Surgery Management

Most cardiac and antihypertensive drugs should

be continued throughout the perioperative periodexcept, aspirin, diuretics and anticoagulants

History to determine effort tolerance, clinicalexamination for cardiac failure and an

electrocardiogram in all patients. Echocardiography can help in assessing an

ejection fraction in borderline cases


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Underlying Renal Complications of

Diabetes and Surgery Renal

Renal dysfunction

Intrinsic renal disease including glomerulosclerosis and renal

papillary necrosis enhance the risk of acute renal failureperioperatively

Proteinuria is an early manifestation

Dialysis should optimally be done the day before surgery.

Urinary infection Management

Urea and electrolyte determination.

Dipstix urinalysis for proteinuria


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Underlying Nervous System

Complications of Diabetes and

Surgery Nervous System

Counter-regulatory response to hypoglycaemia

Peripheral glove and stocking neuropathy with anincreased susceptibility to iatrogenic nerve injuries

Cardiac Autonomic Neuropathy

Management

History of postural dizziness, post gustatorysweating, nocturnal diarrhoea and impotence.

Careful documentation of peripheral sensation
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Underlying Orthopaedic

Complications of Diabetes and

Surgery Small Joint Disease

Non-enzymatic glycosylation causing abnormal cross-linking ofcollagen may lead to joint rigidity

At the atlanto-occipital joint, it may result in difficult intubation

The small joints of the fingers and hands are also affected

failure to approximate the palmar surfaces of theinterphalangeal joints are indicators of a difficult

laryngoscopy (positive prayer sign)

Management

Clinical assessment of neck extension, examination of thesmall joints of the hand and a good evaluation of the ease ofintubation

U d l i I C li i


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Underlying Immune Complications

of Diabetes and Surgery

Immune and infectious risk

Diabetics are susceptible to infection and have delayed woundhealing

Hyperglycaemia

facilitates proliferation of bacteria and fungi depresses the immune system management

Proteolysis and decreased amino acid transport retards woundhealing.

Loss of phagocytic function increases the risks of post-operativeinfection

Management

Need very strict sterile techniques and need to assess risk/benefit

ratio for procedures e.g catheterisation


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Underlying Gastrointestinal and

Opthamological Complications of

Diabetes and Surgery Gastrointestinal

Gastroparesis

Management

History of early satiety and reflux

H2 blocker and metoclopramide

Ophthalmology

Cataracts, glaucoma and retinopathy decrease visual acuity

and increase the unpleasantness of the perioperative period

Management

Increase the amount of explanation and reassurance to thepatient.

P i i l f M i Di b ti


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Principles of Managing Diabetics

During Surgery

Management of preoperative insulin therapy dependson baseline blood glucose, level of diabetic control,severity of illness and the proposed surgicalprocedure

However, aims for all diabetic patients are:

No excess mortality

No increase in post-op complications

Normal wound healing No increase in duration of hospitalisation

No hypoglycaemia, hyperglycaemia orketoacidosis


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Pre-operative Assessment

This is the most important step in the management of

the diabetic patient

Involves a thorough history and physical examination

Review prior anaesthetic records to determinewhether there were any difficulties with intubation oranaesthetics

Lab investigations

blood glucose - K+

BUN - creatinine

ketones - proteinuria

HbA1c (to assess how well controlled diabetes is)


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Pre-Operative Management Admit as early as possible prior to surgery

Avoid long-acting glucose lowering agents chlorpropamide glibenclamide

ultralente insulins

Avoid metformin

Closely monitor blood glucose levels

2 hourly for Type 1

4 hourly for type 2

Test urine every 8 hours for ketones Place first on morning operating list if possible

Aim for a blood glucose of 5-10mmol/L

S i l M t f I li


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Surgical Management of Insulin

Dependant Diabetes Mellitus

Aim to keep blood glucose 5 to10mmol/L Pre operative

NBM for 6 hrs prior to surgery (4 hrs for clear fluids)

Anti aspiration prophylaxis

Initiate glucose/ potassium/ insulin regime after commencing

NBM (check K+ as well)

500ml 10% glucose solution with 20mmol K+ at 1ml.kg-1.hr-1 connected to Y piece with insulin syringe

Make up insulin syringe as 50 units insulin in 50 ml saline

in a 50 ml syringe pump and run through Y piece with10% glucose at between 1 to 5 u hr-1 (1 5 ml).

Base on existing insulin regime

Use sliding scale e.g. 1 u hr-1 if BG between 5 to 10

Hourly capillary glucose is measured until operation


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Dependant Diabetes Mellitus Intra-operative

Hourly glucose monitoring

keep between 5-10 mmol/L

Two hourly potassium monitoring

keep between 3.5-4.5 mmol/L

Anaesthesia determined by patientphysiology and surgical requirements

Set up additional IV for resuscitation fluids


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Dependant Diabetes Mellitus Post-operative

Continue Glucose/Potassium/Insulin

regime until patient can take orally Oral medication with first meal

Allow for pain resulting in increased insulin

requirements


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Surgical Management of Non Insulin


Treat as insulin dependant if:

poorly controlled (blood glucose >10 mmo/L)

major surgery

Pre-operative Biguanides must be stopped 48 hours before hand for fear of

lactic acidosis

NBM for 12 hours prior to operation

Start i.v maintenance fluid 0.18% NaCl with glucose 4%

Hourly capillary glucose is measured until operation


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Surgical Management of Non Insulin


Hourly glucose monitoring

Aim to keep within 5-10mmol/L

if blood glucose >10 mmol/L, switch totreating as insulin dependant

Post-operative

Restart oral hypoglycaemics with first meal


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Other Considerations with

Anaesthesia in Diabetic Patients Usual intra-operative monitoring

record BP and pulse every 5 minutes

watch skin colour and temp

suspect hypoglycaemia if patient is cold and sweaty

give IV glucose

No contraindications to standard anaesthetic induction orinhalational agents

If the patient is dehydrated then hypotension will occur and i.v.fluids will be needed


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Conclusion

The diabetic patient presents numerouschallenges to management during surgery

Awareness of the complications shouldenable tight metabolic control

Correct management of the diabeticpatient during surgery reduces morbidityand length of admission, as well asresulting in better wound healing

management of diabetes patients in surgery

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