Diabetes Mellitus and the Surgical Patient Dr. Cathy Code Division of General Internal Medicine.

Diabetes Mellitus Diabetes Mellitus and the Surgical and the Surgical

PatientPatient

Dr. Cathy CodeDr. Cathy Code

Division of General Internal Division of General Internal MedicineMedicine

ObjectivesObjectives::

Review the effects of surgery on Review the effects of surgery on carbohydrate metabolism and glucose carbohydrate metabolism and glucose controlcontrol

Provide an overview of the preoperative Provide an overview of the preoperative assessment of the diabetic patientassessment of the diabetic patient

Discuss postoperative diabetic Discuss postoperative diabetic management and associated management and associated complicationscomplications

Review the recent evidence for “tight” Review the recent evidence for “tight” glycemic controlglycemic control

Diabetes MellitusDiabetes Mellitus

Common disorder with increasing Common disorder with increasing incidenceincidence

5% of the North American population5% of the North American population In general, diabetics are in poorer In general, diabetics are in poorer

health leading to more surgical health leading to more surgical proceduresprocedures

50% chance that a diabetic will 50% chance that a diabetic will require surgery in their lifetimerequire surgery in their lifetime

Diabetes MellitusDiabetes Mellitus Diabetic microvascular and Diabetic microvascular and

macrovascular complications lead to macrovascular complications lead to an increased need for surgeryan increased need for surgery

Surgery to address:Surgery to address:– Renal failure and its treatmentRenal failure and its treatment– Cataracts and retinal diseaseCataracts and retinal disease– Foot ulcerFoot ulcer– PVDPVD– CADCAD

DiabetesDiabetes

Type 1 DMType 1 DM:: No residual B cell No residual B cell

activityactivity Dependent on Dependent on

exogenous insulinexogenous insulin Do not respond to Do not respond to

OHGOHG Can become Can become

ketoticketotic

Type 2 DMType 2 DM:: Insulin resistantInsulin resistant Associated with Associated with

obesityobesity Treated with diet, Treated with diet,

OHG +/- insulinOHG +/- insulin Can develop HONKCan develop HONK Rarely develop Rarely develop

DKADKA

Type 2 DiabetesType 2 Diabetes

Diet therapyDiet therapy

Biguanides ex. MetforminBiguanides ex. Metformin

Sulfonylureas ex. GlyburideSulfonylureas ex. Glyburide

Thiazolidinediones ex. Avandia, ActosThiazolidinediones ex. Avandia, Actos

Alpha-glucosidase Inhibitors ex. Alpha-glucosidase Inhibitors ex. PrandasePrandase

Meglitinides (non sulfonylurea Meglitinides (non sulfonylurea secretagogues) ex. Gluconormsecretagogues) ex. Gluconorm

Insulin requiring Insulin requiring DiabetesDiabetes

Insulin TherapyInsulin Therapy::– Once daily dosing (qhs, qam)Once daily dosing (qhs, qam)

– BID dosing (ex. 30/70, 20/80)BID dosing (ex. 30/70, 20/80)

– BID intermediate insulin with short BID intermediate insulin with short acting ac meals (lispro or regular)acting ac meals (lispro or regular)

– Continuous SC insulin pumpContinuous SC insulin pump

Diabetics and SurgeryDiabetics and Surgery

Requires understanding of CHO Requires understanding of CHO metabolismmetabolism

Liver plays central role Liver plays central role InsulinInsulin

– Major anabolic hormoneMajor anabolic hormone– Most active in “Fed” state Most active in “Fed” state

(gycogenesis/lipogenesis)(gycogenesis/lipogenesis)– Stimulates glucose uptake into fat and Stimulates glucose uptake into fat and

musclemuscle– Promotes protein anabolismPromotes protein anabolism

Diabetes and SurgeryDiabetes and Surgery

Insulin deficiency or resistance Insulin deficiency or resistance mimicks the “Fasting” statemimicks the “Fasting” state

– Glycogen/fat/protein are catabolized to Glycogen/fat/protein are catabolized to maintain energy productionmaintain energy production

– Glucagon promotes gluconeogenesis Glucagon promotes gluconeogenesis and glycogenolysis in liverand glycogenolysis in liver

– Cortisol promotes protein breakdownCortisol promotes protein breakdown– Catecholamines cause lipolysis and Catecholamines cause lipolysis and

glycogenolysisglycogenolysis

Diabetes and SurgeryDiabetes and Surgery

Energy homeostasis maintained at Energy homeostasis maintained at expense of body storesexpense of body stores

Surgery and anesthesia are major Surgery and anesthesia are major stresses that influence glucose stresses that influence glucose homeostasishomeostasis

Counter regulatory hormones Counter regulatory hormones cause insulin resistance and cause insulin resistance and hyperglycemiahyperglycemia

Diabetes and SurgeryDiabetes and Surgery

General Anesthesia suppresses General Anesthesia suppresses endogenous insulin secretionendogenous insulin secretion

Vasoactive substances can exert Vasoactive substances can exert anti-insulin effectsanti-insulin effects

In DM, insulinopenia leads to In DM, insulinopenia leads to hyperglycemia, increased osmolality, hyperglycemia, increased osmolality, hypovolemia, abnormal electrolytes, hypovolemia, abnormal electrolytes, and in extreme DKA or HONKand in extreme DKA or HONK

Diabetes and SurgeryDiabetes and Surgery

Other concerns beyond insulin:Other concerns beyond insulin:

CADCAD Autonomic neuropathyAutonomic neuropathy Peripheral neuropathyPeripheral neuropathy Diabetic nephropathyDiabetic nephropathy Wound healingWound healing InfectionsInfections

Preoperative Preoperative AssessmentAssessment

Historical featuresHistorical features– Cardiac history and current symptomsCardiac history and current symptoms– Other medical conditionsOther medical conditions– Long term diabetic complicationsLong term diabetic complications– Baseline glycemic controlBaseline glycemic control– Hypoglycemic events?Hypoglycemic events?– Current diabetic treatment Current diabetic treatment – Type of surgery Type of surgery – Type of anesthetic plannedType of anesthetic planned

Preoperative Preoperative AssessmentAssessment

ExaminationExamination

Lab tests:Lab tests:

– Glucose +/- Hgb Glucose +/- Hgb A1CA1C

– Renal functionRenal function– ElectrolytesElectrolytes

ECGECG OtherOther

Preoperative AssessmentPreoperative Assessment Aim for optimal glycemic control Aim for optimal glycemic control

(depending on urgency of OR)(depending on urgency of OR) Goal of blood sugar < 11.0Goal of blood sugar < 11.0 BenefitsBenefits

– Normal fluid and electrolyte balanceNormal fluid and electrolyte balance– Reduced insulin resistanceReduced insulin resistance– Improved endogenous Beta cell Improved endogenous Beta cell

responsiveness (T2DM)responsiveness (T2DM)– Decreased hepatic gluconeogenesisDecreased hepatic gluconeogenesis– Improved WBC function and wound Improved WBC function and wound

healinghealing

Preoperative Preoperative ManagementManagement

General goal to avoid marked General goal to avoid marked hyperglycemia and avoid hyperglycemia and avoid significant hypoglycemiasignificant hypoglycemia

Procedures should be arranged Procedures should be arranged as early in the day as possibleas early in the day as possible

Preoperative Preoperative ManagementManagement T2DM on diet therapyT2DM on diet therapy::

– NPO for procedureNPO for procedure– Usually do not require any specific therapy Usually do not require any specific therapy

preoppreop– Supplemental SC short acting insulin (regular Supplemental SC short acting insulin (regular

or lispro) if required for BS > 11.0or lispro) if required for BS > 11.0

T2DM on OHGT2DM on OHG::– Last dose of OHG night before ORLast dose of OHG night before OR– NPO for procedureNPO for procedure– +/- IV glucose pre op +/- IV glucose pre op – Supplemental SC short acting insulin (regular Supplemental SC short acting insulin (regular

or lispro) if required for BS > 11.0or lispro) if required for BS > 11.0

Preoperative ManagementPreoperative Management – –

DM on insulinDM on insulin Typically can Typically can

continue SC insulin continue SC insulin perioperativelyperioperatively

Preop evening dose Preop evening dose of insulin decreased of insulin decreased to ~ 2/3 to prevent to ~ 2/3 to prevent am hypoglycemiaam hypoglycemia

May require preop May require preop IV glucose or insulinIV glucose or insulin

Preoperative ManagementPreoperative Management – –

DM on insulinDM on insulin Short, early morning OR, Short, early morning OR,

breakfast only delayed:breakfast only delayed:– Delay usual morning insulinDelay usual morning insulin– Administer insulin only after OR when Administer insulin only after OR when

and able to eatand able to eat

DM on InsulinDM on Insulin::

Morning procedure, breakfast to Morning procedure, breakfast to be missed, lunch to be eaten:be missed, lunch to be eaten:

– Once daily insulinOnce daily insulin 2/3 of am insulin (intermediate acting)2/3 of am insulin (intermediate acting)

– BID insulinBID insulin 1/2 of am insulin as intermediate acting1/2 of am insulin as intermediate acting

DM on InsulinDM on Insulin

Morning procedure, breakfast and Morning procedure, breakfast and lunch meals to be missed:lunch meals to be missed:

– Once daily insulinOnce daily insulin 1/2 of total am insulin as intermediate acting insulin1/2 of total am insulin as intermediate acting insulin

– BID insulinBID insulin 1/3 of total am insulin as intermediate acting insulin1/3 of total am insulin as intermediate acting insulin

– Insulin PumpInsulin Pump Continue basal infusion rateContinue basal infusion rate

DM on InsulinDM on Insulin

Procedure later in the dayProcedure later in the day::– Need to avoid metabolic changes of Need to avoid metabolic changes of

starvationstarvation

– Overall give less insulin and IV glucose Overall give less insulin and IV glucose infusioninfusion Once daily insulinOnce daily insulin

– 1/2 of total am insulin as intermediate acting1/2 of total am insulin as intermediate acting BID insulinBID insulin

– 1/3 of total am insulin as intermediate acting1/3 of total am insulin as intermediate acting Insulin pumpInsulin pump

– Continue basal infusion rateContinue basal infusion rate

DM on InsulinDM on Insulin

Long and complex procedures:Long and complex procedures:

– IV insulin infusion IV insulin infusion SafeSafe Start the am of ORStart the am of OR Short ½ life allows for precise glucose Short ½ life allows for precise glucose

managementmanagement

– SC insulinSC insulin Marked variability of glucose concentrationsMarked variability of glucose concentrations

Postoperative Postoperative ManagementManagement

The pre operative DM regimen may be The pre operative DM regimen may be reinstated once the patient is eating reinstated once the patient is eating wellwell

SC sliding scales are often used to SC sliding scales are often used to bridge the gap butbridge the gap but– Cause wide fluctuations in glucose controlCause wide fluctuations in glucose control– Not physiologicNot physiologic– If used should be individualized If used should be individualized – Should supplement a basal regimenShould supplement a basal regimen

Postoperative ManagementPostoperative Management - - InsulinInsulin

Restart insulin at modified dose if Restart insulin at modified dose if requiredrequired

Supplement with SC sliding scale with Supplement with SC sliding scale with mealsmeals

For patient on IV insulin, continue until For patient on IV insulin, continue until eating well and ensure overlap with SC eating well and ensure overlap with SC insulininsulin

Never leave T1DM without insulin – risk Never leave T1DM without insulin – risk for DKAfor DKA

Postoperative ManagementPostoperative Management - - OHGOHG MetforminMetformin

– Contraindicated in severe renal impairmentContraindicated in severe renal impairment– Avoid in conjunction with IV contrastAvoid in conjunction with IV contrast

Sulfonylureas Sulfonylureas – Can induce sig and prolonged hypoglycemiaCan induce sig and prolonged hypoglycemia– Avoid or modify in erratic or poor PO intakeAvoid or modify in erratic or poor PO intake– Deterioration in renal function can increase risk Deterioration in renal function can increase risk

of hypoglycemiaof hypoglycemia ThiazolidinedionesThiazolidinediones

– Associated with fluid retentionAssociated with fluid retention– Avoid in advanced CHFAvoid in advanced CHF

Postoperative ConcernsPostoperative Concerns

TPN/Enteral FeedingTPN/Enteral Feeding GlucocorticoidsGlucocorticoids Cardiac complicationsCardiac complications Poor Wound HealingPoor Wound Healing

– DM associated with increased frequency DM associated with increased frequency of wound infections of wound infections

– Collagen formation, phagocytic activity, Collagen formation, phagocytic activity, chemotaxis and adherence of chemotaxis and adherence of granulocytes adversely affected by granulocytes adversely affected by hyperglycemiahyperglycemia

Postoperative ConcernsPostoperative Concerns

Postop infectionsPostop infections– Impaired phagocytosis and Ab responseImpaired phagocytosis and Ab response

Autonomic neuropathyAutonomic neuropathy– HR/BP, may have unpredictable response to HR/BP, may have unpredictable response to

surgical stresssurgical stress Peripheral neuropathyPeripheral neuropathy

– Higher risk of pressure ulcers, skin necrosisHigher risk of pressure ulcers, skin necrosis Diabetic nephropathyDiabetic nephropathy

– Challenging fluid and electrolyte balanceChallenging fluid and electrolyte balance Diabetic gastroparesisDiabetic gastroparesis

– May cause severe postop nausea and vomitingMay cause severe postop nausea and vomiting

Evidence for “Tight” Glycemic Evidence for “Tight” Glycemic ControlControl

Continuous IV infusion to achieve Continuous IV infusion to achieve glycemic control 4.5-6.0 in postop glycemic control 4.5-6.0 in postop patients that require ICU, mechanical patients that require ICU, mechanical ventilation (NEJM 2001)ventilation (NEJM 2001)

IV insulin intraop for Cardiac surgery IV insulin intraop for Cardiac surgery to achieve blood sugar b/w 5-11.0 to achieve blood sugar b/w 5-11.0 (Ann Thoracic Surg 1999)(Ann Thoracic Surg 1999)

Perioperative glycemic levels b/w 5-Perioperative glycemic levels b/w 5-11.0 in most other surgical situations 11.0 in most other surgical situations (Consensus, CDA)(Consensus, CDA)

ConclusionsConclusions

DM is a common chronic condition with DM is a common chronic condition with a significant subset of complicationsa significant subset of complications

A condition requiring an increased A condition requiring an increased number of surgical proceduresnumber of surgical procedures

Perioperative management is complex Perioperative management is complex Patients are at risk for increased Patients are at risk for increased

morbidity and mortality without morbidity and mortality without adequate preop optimization and adequate preop optimization and vigilant postop follow up vigilant postop follow up