Perioperative Management of Diabetic Patient - Dr PSN Raju
Perioperative Management of
the Diabetic Patient
• Diagnostic criteria
• Physiology of glucose metabolism
• Complications of diabetes
• Pre - anaesthetic evaluation
• Problems faced by a diabetic for surgery
• Goals and methods of achieving periop glycemic control
• Anaesthetic technique and the diabetic patient
• Medical / legal pitfalls
• Diabetes mellitus is defined as a syndrome
characterized by sustained hyperglycemia
due to insulin deficiency, impaired insulin
action or a combination of both.
• Diabetes currently affects 246 million people worldwide and is
expected to affect 380 million by 2025.
• In 2007, the five countries with the largest numbers of people
with diabetes are
• India (40.9 million)
• China (39.8 million)
• United States (19.2 million)
• Russia (9.6 million)
• Germany (7.4 million).
• Each year 3.8 million deaths are attributable to DM.
• Cardiovascular disease is the major cause of death in
diabetes, accounting for some 50% of all diabetes
fatalities, and much disability.
• Every 10 seconds a person dies from diabetes-
Diagnostic criteria for diabetes according to
1 mmol = 18 mgs
• Type 1 DM :
– absolute insulin deficiency,
– unopposed catabolic action leads to
hyperglycemia and diabetic ketoacidosis.
• Type 2 DM:
– peripheral resistance to insulin,
– less susceptible to developing ketoacidosis.
• Mortality / morbidity rates in diabetics have been
estimated to be up to 5 times greater than in
Related to the end-organ damage.
• DM is an independent predictor of postop
myocardial ischemia and infectious
complications in patients undergoing surgery.
• The ultimate goal in the management of
diabetic patients is to achieve equivalent
outcomes as those patients without DM.
• A strong grasp of the complexities of glucose
insulin interrelationship and of the effects of
anesthesia and surgery is essential to optimal
management and outcomes.
• Glucose metabolism is largely a function of the
liver, the pancreas, and, to a lesser degree,
• Role of liver in glucose regulation:
• Extracts glucose
• Stores it in the form of glycogen
• Performs gluconeogenesis
• Pancreas secretes counterregulatory hormones:
– Insulin from islet beta cells, which lowers blood glucose
– Glucagon from islet alpha cells, which raises blood
• Additional contributors to glucose metabolism
include the catabolic hormones: epinephrine,
glucocorticoids, and growth hormone, which all
raise blood glucose concentrations.
• Peripheral tissues participate in glucose
metabolism by extracting glucose for energy
needs, thus lowering blood glucose levels.
• Suggestive symptoms - polyuria/polydipsia, blurred vision
• Current Rx of diabetes, including medication
regimen, diet, and glucose monitoring results
• Frequency, severity, and etiology of acute
complications (ketoacidosis / hypoglycemia)
• Prior or current infections (eg, skin, foot, dental, genitourinary)
• Symptoms and treatment of chronic eye; kidney; nerve;
genitourinary, bladder, and GI function; heart; peripheral
vascular; foot; and cerebrovascular complications
• Nondiabetic medications that may affect blood glucose
levels (eg, corticosteroids)
• Severity and type of the diabetic state
• Anti-diabetic Medications
• Control of blood sugar
• Treatment regimens used
• Associated complications of DM
• Airway assessment
• Comorbid conditions
• Most commonlya distal symmetrical sensory
polyneuropathywith a variable degree of
• Autonomicdysfunction, which is of particular
importance to the anaesthetist,is detectable in up
to 40% of type 1 and 17% of type 2 diabetic
Pathogenic mechanisms for ANP
• Local ischaemia,
• Tissue accumulationof sorbitol
• Altered function of neuronal Na+
• Immunologically mediated damage
• Diabetic gastroparesis is characterized by a
delay in gastricemptying without any
gastric outlet obstruction.
• The increasedamount of gastric contents
enhances the risk of acid aspirationduring
the induction of anaesthesia
• Gives insight into
the patient's risk
stiff joint” syndrome,
• Significant risk during airway management.
• Affects temporomandibular, atlantooccipital, and
other cervical spine joints.
• Short stature and waxy skin.
Related to chronic hyperglycemia and nonenzymatic
glycosylation of collagen and its deposition in joints.
• A positive “prayer sign” can be
elicited on examination with the
patient unable to approximate the
palmar surfaces of the phalangeal
joints while pressing their hands
• Represents cervical spine immobility
and the potential for a difficult
endotracheal intubation .
• Further airway evaluation should
include assessment of thyroid
gland size, as patients with type 1
DM have a 15% association of
other autoimmune diseases, such
as Hashimoto thyroiditis and
• The degree of preoperative neurological
dysfunction is important to document, especially
prior to regional anesthesia or peripheral nerve
blocks, to assess the degree of subsequent
• Studies have shown a correlation between preop
proteinuria and postop death after CABG, with
the mortality rate increasing proportionally with
the concentration of protein in the urine.
• Based on the nature of surgery, ECG assessing
R-R interval during respiration may be useful in
the evaluation of autonomic neuropathy.
Loss of R-R variability when the HR at maximal
inspiration is compared with the HR at maximal
expiration implies the presence of autonomic cardiac
GENERAL PREOP MANAGEMENT
• On the day of surgery, patients on oral
regimens should be advised to discontinue
Sulfonylureas, meglitinides have the potential
to cause hypoglycemia.
• Sulfonylureas have been associated with
interfering with ischemic myocardial
preconditioning and may theoretically
increase risk of perioperative myocardial
ischemia and infarction.
• Patients taking metformin should be
advised to discontinue this drug
because of the risk of developing lactic
• For these patients, short-acting insulin may
be administered s/c as a sliding scale or as a
continuous infusion,to maintain optimal
glucose control, depending on the extent of
• Patients who are insulin-dependent (type 1)
should be advised to reduce their bedtime
dose of insulin the night prior to surgery to
prevent hypoglycemia, while NBM.
Problems faced by a diabetic for
• Surgical stress response with catabolichormone secretion
• NBM, which maybe prolonged following GI procedures
• Alteredconsciousness - masks the symptoms of
• Circulatorydisturbances - whichmay alter the absorption of
METABOLIC RESPONSE TO
ANESTHESIA AND SURGERY
• Surgery induces a considerable stress response
mediated by the neuroendocrine system through the
release of catecholamines, glucagon, and cortisol.
• The principal mechanism lies with the elevation of
sympathetic tone with a subsequent release of
cortisol and catecholamines during surgery.
• A nondiabetic patient is able to maintain glucose
homeostasis by secreting a corresponding
amount of insulin to balance the glucose
generated by the stress response.
• This compensatory mechanism in diabetic
patients is impaired through a relative insulin
deficiency (type 2) or absolute insulin deficiency
(type 1) necessitating supplementation of
insulin in the perioperative period.
• Anesthetic agents can affect glucose metabolism
through the modulation of sympathetic tone; in vitro
evidence suggests that inhalational agents suppress
• The resulting relative insulin deficiency often leads
to glucose dysregulation and hyperglycemia.
• The use of regional anesthesia or peripheral
nerve blocks may mitigate these concerns,
but no data suggest that these forms of
anesthesia will improve postoperative survival
in patients with DM.
GOALS OF PERIOPERATIVE
• The goals for glycemic control are tailored to
each patient based on:
• Nature of surgery,
• Severity of underlying illness,
• Modality used to achieve glycemic control
• Patient age,
• Sensitivity to insulin.
• Prior to elective surgery, it is ideal for patients
to have their HbA1c < 6%.
• Less intensive glycemic control may be
indicated in patients with severe or frequent
episodes of hypoglycemia.
• Intravenous insulin is the most flexible and
readily titratable agent, with few, if any,
contraindications, making it an ideal agent for
• The length, type of surgery, and degree of
glycemic dysregulation will dictate the degree
of supplemental intravenous insulin therapy.
• Patients with type 1 diabetes should have
elective surgeries scheduled as the first case
of the day to minimally disrupt their DM
• Administer half of their daily dose of long-
• Arrive at the preop admitting area early
enough to have an I.v infusion of dextrose
instituted and their serum glucose monitored
until the time of surgery.
• Establish separate iv access for a “piggyback”
infusion of regular insulin .
• The infusion rate can be determined by using the
formula: insulin (U/h) = serum glucose (mg/dL)/150.
• Intravenous glucose solution should be administered
concomitantly to avoid hypoglycemia.
• Typically, a 5% D solution is started when
serum glucose levels are less than 150 mg/dL.
• Patients suspected of gastroparesis should
receive a prokinetic drug prior to general
anesthesia to decrease the incidence of
gastric acid aspiration.
• Aseptic technique is critical for all procedures
in patients with DM to decrease the incidence
of postoperative infection.
• Temperature control is also essential in
patients with DM, as hypothermia can lead to
peripheral insulin resistance, hyperglycemia,
deceased wound healing, and infection.
• Intraop management of intravascular volume
may require the use of a central venous
pressure catheter, a pulmonary artery
catheter, or TEE to best guide therapy and to
protect against end-organ hypoperfusion.
• Arterial blood gas analysis should not only
include assessment of blood glucose levels
but also levels of sodium, potassium, and
assessment of pH.
• Type 1 diabetic patients are predisposed to
developing ketoacidosis during periods of
major stress; therefore, they should be
monitored by arterial blood gas analysis
during and after major surgery.
General guidelines for periop control
• Check blood glucose, urea, electrolytes and urinary
• Adjust insulin therapy BD – soluble isophane insulin
• Poor control: change to TID – soluble insulin and delay
• Urgent surgery: glucose insulin infusion
Day of surgery
• Check fasting sugar
• No subcutaneous insulin
• Start 10% D (500ml) with 10 U human insulin and KCI
1Ommol for 4-6 h
• Adjust insulin according to the blood sugar values
<4 No insulin
4-6 Insulin 5 U / 500 mL 10%glucose
6-10 Same as above
10-20 15 U/ 500 Ml 10% glucose
>20 20 U/500 mL 10%glucose
• K+ is adjusted according to serum K+
K+<3 mmol/L add 20 mmol K+/500 ml
K+>5 mmol/L no KCI
Postop major surgery
• Check blood sugar every 2-6 h
• Check urea, electrolytes every 4-6h
• Continue infusion till oral feeding is established
• If feeding is delayed, change to 20% glucose with less
• When oral diet is established, q8h soluble insulin prior to
• When insulin requirements are stable,restart the
Emergency surgery and DKA
• DKA results from inadequate insulin dosage
or increased insulin requirement often
precipitated by trauma, infection or surgical
• Administer insulin at the rate of 4-8U/hr,
depending on factors such as blood sugar
levels, ketosis and acidosis.
• Correct dehydration, sodium depletion and
subsequent potassium depletion
• Replace fluids with isotonic solution of NaCI 1 L in 30
min,1 L in the next hour and further 1 L over the next
• Monitor blood glucose levels, arterial pH and blood
• K+may be normal or elevated due to presence of
• Magnesium 5-10 mmol is also required along with K+
• 5% D can be started when blood glucose decreases
to 15 mmol/L
• Surgery is ideally carried out after reversal of acidosis and
• However, if the indication for surgery is emergent, surgery
can be started when volume resuscitation is underway,
with the diabetic management being continued in the
intraop and postop periods.
Tight control of blood glucose
• Tight control of blood sugar between 80 – 120 mgs/dL
– Prevents ischemia
– Improves wound healing
– Improves weaning from CPB
REGIMEN - 1
• Preprandial sugar levels on the evening before
• Start infusion of 5% D at the rate of 50 ml/hr
• To this infusion, piggyback regular insulin 50 U in
250 ml 0.9 Nacl.
• Set the infusion rate U/hr = Plasma glucose
REGIMEN - 1
• Repeat glucose values q4h, and adjust insulin infusion
to achieve plasma glucose of 100-200 mg/dl.
• Intraop - use non dextrose containing fluids.
• Determine plasma glucose q2h and adjust insulin
• Serum K+ should be checked and adjusted accordingly
with particular care for poor renal function.
Anaesthetic technique and the
• Regional blockade, may modulate the secretionof
the catabolic hormones and any residual insulin
• The periop increase in circulating glucose,
epinephrineand cortisol concentrations found in
non-diabetics exposedto surgical stress under GA
is blocked by epiduralanaesthesia
• The perioperative infusion of phentolamine,a
competitive -adrenergic receptor blocking drug,
decreasesthe glycaemic response to surgery by
partially reversing thesuppression of insulin
• Regional anaesthesia may carry greater
risks in the diabeticpatient with autonomic
• Profound hypotension mayoccur with
deleterious consequences in a patient with
co-existingcoronary artery, cerebrovascular
or renovascular disease
Medical / Legal Pitfalls
• Overtreatment or undertreatment of hypoglycemia,
eg, premature discharge of a patient who develops
hypoglycemia due to a sulfonylurea agent, is a pitfall.
• Failure to record the blood glucose levels of patients
with wounds or active infections when they are <250
mg/dL is a pitfall and may lead to poor healing.
Medical / Legal Pitfalls
• Failure to provide adequate hydration to patients
with mild diabetic nephropathy before contrast
material is given may precipitate acute renal failure.
• Failure to examine the patient's feet and failure to
detect small ulcers or underestimation of their
seriousness are also pitfalls.
• Failure to consider myocardial ischemia in patients
with nonspecific symptoms is a pitfall.
• There have been major advances in the last few years in
understanding and treating complications of diabetes.
• The main focus has been on good glycemic control.
• The incidence of diabetes is on the rise in most
populations, with Indians being more prone to develop
• Diabetes mellitus is likely to be the most common
comorbid factor encountered in Surgical practice.
• A clear understanding of the metabolic process, well
controlled glycemic regimens and excellent periop
care will go a long way towards decreasing the
mortality and morbidity in diabetes patients.