Management of Anesthesia

8/7/2019 Management of Anesthesia

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Management of Anesthesia

Diabetes Mellitus



AIM

� Avoid hypoglycaemia which can cause irreversiblecerebral damage.

� Avoid severe hyperglycaemia resulting in osmotic

diuresis and severe dehydration (>14 mmol/litre).� Avoid large swings in glucose, i.e. maintain blood

glucose in the range 610 mmol/litre

� Supply cells with insulin so that intracellular

glucose starvation does not occur, preventingketoacidosis

� Prevent hypokalaemia, hypomagnesaemia, andhypophosphataemia.



Preoperative assessment� CVS : the diabetic is prone to HTN, IHD, cerebrovascular disease,

MI and cardiomyopathy. Autonomic neuropathy can lead totachy- or bradycardia and postural hypotension. Diabetics havethree times the incidence of ischaemic heart disease, and thismay be silent.

� Autonomic neuropathy (present in 50%) increases the risk of unstable BP, MI, arrhythmias, gastric reflux, and hypothermia

during surgery.� Renal: 40% of diabetics develop microalbuminuria, which is

associated with HTN, IHD, and retinopathy. This may be reducedby treatment with ACE inhibitors.

� Respiratory: diabetics are prone chest infections, especially in

obese and smokers.� Airway: thickening of soft tissues (glycosylation) occurs,

especially in ligaments around joints-the limited joint mobilitysyndrome. If the neck and mouth opening is affected there maybe difficulty in intubation.



� Gastrointestinal: 50% have delayed gastric emptyingand are prone to reflux.

�Eyes: cataracts are common, especially in the elderlydiabetic.

� Immunity: Diabetics are prone to infections.

� Miscellaneous: diabetes may be caused or worsened

by treatment with corticosteroids, thiazide diuretics,and the contraceptive pill. Thyroid disease, obesity,pregnancy, and stress can also affect diabetic control.

� High blood glucose levels are frequently found onadmission to hospital, presumably stress related, andmay settle spontaneously.

� It is not necessary to admit diabetics 2 days beforesurgery, unless there are major problems with diabeticcontrol.



Investigations

� Blood sugar, Measure blood sugarpreoperatively.

� Test urine for ketones and sugar,

� A glycosylated haemoglobin (HbsAc) >9%suggests inadequate control of the bloodglucose(normal 3.86.4%).

� All diabetic patients should obtain ECG, ECHOif cardiac problems present.

� Blood urea, s. creatinin, s.electrlytes to bedone



Preoperative management

� Place first on operating list.

� Evaluate for possible cardiac and renal diseases,control of hypertension, manage with insuline

and glucose during starvation.� Stop OHA 24 48 hrs before surgery Metformin

and glibenclamide precipitate lactic acidosis.

� Chlorpropamide should ideally be stopped 3 days

before surgery because of its long action. This isoften not possible and should not pose a majorproblem if frequent blood glucose monitoring isundertaken



Management of insulin- preoperative

�2/3

rd

of usual bedtime dose of insulin should be giventhe night before surgery and half the usual HPN doseon the day of surgery. Regular insulin should bewithheld on the morning of surgery.

� A 5% dextrose with 0.45% NS (D51/2NS) iv infusion @100ml/Hr should be started pre-op

� Insulin Pump : Overnight rate should be decreased by30%. At basal rates on the day of surgery (0.3U x Wt ) ivor S/c. Pt can be given Glargine ( long acting) and Pump

discontinued in 60-90 mts.

� Pt on Glargine, lispro and aspart : 2/3rd of glargine andentire lispro or aspart on the night before and stop allinsulin on the day of surgery.



� For major surgery should be delayed ( 4-6Hrs)

if serum glucose is > 270mg/dl for rapid

control with insulin.

� All elective Surgery should be postponed if BS

is > 400mg/dl until sugars are controlled.



Emergency surgery� Postponed if high sugar levels if possible for 4- 6 hrs for

control.� DKA Treat with Normal saline ( Rehyration) 1l/hr for first 2

hours and 0.4% NS @ 250-500ml/hr. Total fluid deficit is 50 100ml/kg.

� An insulin bolus of 0.1 U/kg followed by an infusion of 0.1

U/kg per hour. Serum glucose is monitored hourly. Decreasedose rate by 50% when serum HCO3 rises above 16mEq.

� electrolytes are monitored every 2 hours. Potassium,magnesium, and phosphate deficits are replaced when urineproduction is documented.

� Potassium: if serum K= ______mEq/l, give_____mEq over nexthour <3 40

3-4 30

4-5 20

5-6 10

<6 0



� Phosphate : if serum PO4 is < 1.0 mg/dl, give

7.7mg/kg over 4 hrs.� When serum glucose decreases to less than 250

mg/dL, intravenous fluids should includedextrose. Insulin is continued until acidosisresolves. Sodium bicarbonate is not routinelygiven and is reserved for cases where the pH isless than 7.10.

� HHS Treat with normal saline and similar dosesof insulin compared to patients with DKA. These

patients are at significant risk of developing of cerebral edema and therefore correction of serum glucose and osmolarity should proceedgradually over a 12- to 24-hour period.



Intraoperative management

� Goals to minimize hyperglycemia ( RBS 120 to 180mg/dl)

� RBS > 180mg/dl should be treated with Insulin/glucoseregime.

� Check RBS hourly and ketones 4th hourly.

� RL should be avoided Lactate converts to glucose.

� Rapid sequence induction if gastric stasis suspected.

� Regional techniques are better chart all pre-existing

nerve damage.� Autonomic dysfunction may exacrbate the hypotension

effect of SA & EA.



Intra-operative hypoglycemia� RBS <60mg/dl should be treated ( caused by fasting, recent

alcohol consumption, liver failure, septicaemia,sulfonylureas, biguanides, thiazolidinediones, ACEinhibitors, MAO inhibitors, and nonselective -blockers).

� Signs and symptoms : tavhycardia, light-headedness,sweatingand pallor may progress to confusion,restlessness,

incomprehensible speech, double vision, convulsions andcoma. All this is made worse by hypotension and hypoxia.

� Treatment : stop all insulin infusion.

if patient conscious - 25ml of D50% if not availablenasogastric and oral sugars 15-20g.

if unconscious 50ml of D50% , iv glucose ( 0.5g/kg) orglucagon 1mg im/iv/sc.

Recheck BG after 20mts repeat 2minutes of D50 iv if <60mg/dl.Restart insulin infusion if >70mg/dl for 2 checks.



IV insuline/dextrose infusion regime

� Start iv 5% dextrose at 120ml/hr or 10% dextroseat 60ml/hr ( D51/2NS or D 4.5% and 0.18% NS)

� If serum K+ < 4.5 mmol/l add 10mmol Kcl to

500ml bag of dextrose.� Intravenous insulin according to sliding scale as

shown in table.

� Always infuse insulin in the same line wheredextrose is going, discard first few ml of insulincontaining solution as it may react and getabsorbed by plastic tubing.



Intravenous insulin sliding scaleBlood glucose (mmol/L) Insulin infusion rate (u/hr) Insulin infusion rate if

blood glucose not

maintained <10

mmol/litre (unit/h)

<3 Stop review after 30mts Stop review after 30mts

3- 4 0.5 0.5

4.19 1 2

9.113 2 3

13.117 3 4

17.128 4 6

>28 6 (check infusion running

and call doctor)

8 (check infusion running

and call doctor)



Inpatient Insulin Algorithm� Goal BG: ________mg/dL

�

Standard Drip: Regularinsulin 100 units/100 mL0.9% NaCl via infusiondevice

Initiating the infusion

� Bolus dose: Regular insulin0.1 unit/kg=______units

� Algorithm1: Start here formost patients.

� Algorithm2: Start here if w/p CABG, s/p solid organtransplant or islet celltransplant, receiving

glucocorticoids,vasopressors or diabeticsreceiving>80 units/day of insulin as an outpatient

ALGORITHM 1ALGORITHM

2

ALGORITHM

3

ALGORITHM

4

BG Units/hr Units/hr Units/hr Units/hr

<60=Hypoglycemia (See below for treatment)

<70 Off Off Off Off

70109 0.2 0.5 1 1.5

110119 0.5 1 2 3

120149 1 1.5 3 -5

150179 1.5 2 4 7

180209 2 3 5 9

210239 2 4 6 12

240269 3 5 8 16

270299 3 6 10 20

300329 4 7 12 24

330359 4 8 14 28

>360 6 12 16



� Moving from Algorithm to Algorithm

� Moving up: An algorithm failure is defined as BG outsidethe goal range for 2 hours (see above goal), and the leveldoes not change by at least 60 mg/dL within 1 hour.

� Moving down: When BG is <70 mg/dL for two checks OR if BG decreases by >100 mg/dL in an hour. Tube feeds orTPN: Decrease infusion by 50% if nutrition (tube feeds orTPN) is discontinued or significantly reduced. Reinstitutehourly BG checks every 4 hours.

� Patient Monitoring Check capillary BG every hour until it iswithin goal range for 4 hours, then decrease to every 2hours for 4 hours, and if it remains at goal, may decrease to

every 4 hours.� Treatment of Hypoglycemia (BG <60 mg/dL) - treat as

discussed earlier

� Intravenous Fluids Most patients will need 510 g of glucose per hour (D5W or D5 ½ NS at 100200 mL/hr or

equivalent.



Glucose potassium insulin regime ( GKI or alberti)

� 500ml of 10% dextrose or 5% dextrose + 5 to 20

units actrapid + 10mmol Kcl @ 100l/hr ( providesinsulin 2-3U/hr, potassium 2mmol/hr,glucose10g/hr)

Blood

glucose

(mmol/litre)

Soluble

insulin

(units) to be

added to

each 500 ml

bag

Blood

potassium

(mmol/litre)

KCl (mmol)

to be added

to each 500

ml bag

<4 5 <3 20

46 10 35 106.110 15 >5 None

10.120 20

>20 Review If potassium level not

available, add 10 mmol

KCl to each bag



Post operative care

� Tight glucose control ( 80 110mg/dl) goodneutrophil & macrophage function, beneficialchanges to mucosal/skin barriers, enhanced

erythropoiesis, reduced cholestasis, improvedrespiratory function and decreased axonaldegeneration.

� Stop insulin/glucose regime and calculate totalunits given in last 24hrs and divide it by 4 or 3equal doses and give as s/c doses.



Treatment� The cornerstones of therapy for type 2 diabetes

are diet with weight loss, exercise therapy, andthe oral antidiabetic agents.

� Low-calorie diets (8001500 kcal) and very low

calorie diets (<800 kcal) with limits on cholesterolraising fats and added sugars are used to reducebody fat and decrease insulin resistance and tonormalize plasma glucose, lipids, and

lipoproteins.� Oral Antidiabetic Agents.

� Insulin.









3 or 4 injection regime� Intensive insulin therapy uses three or four daily

injections or a continuous infusion with morefrequent glucose monitoring.

� Three daily injections includes NPH plus short-

acting (regular) or rapid-acting (lispro, aspart)insulin before breakfast, short-acting or rapid-acting insulin before dinner, and NPH insulin atbedtime.

� Four daily injections can include a single injectionof NPH, lente, or insulin glargine (Lantus) atbedtime plus short-acting or rapid-acting insulinbefore breakfast, lunch, and dinner.



Three daily injections



Four daily injections



Four daily injections



Subcutaneous infusion insulin pump�

A subcutaneous infusion pump uses regular or rapid-actinginsulin with a usual range of 0.5 to 2.0 units per hour.

� A typical total daily basal dose of insulin equals weight(kg)×0.3, with the hourly rate obtained by dividing by 24.

�

Basal rates vary during a 24-hour period with lower ratesrequired at bedtime, higher rates between 3 and 9 AM andintermediate rates during the day.

� Premeal boluses may also be used, and insulin rates mustbe adjusted for exercise. Ideal glycemic goals for type 1diabetics include the following: before meals, 70 to 120mg/dL; after meals, less than 150 mg/dL; at bedtime, 100to 130 mg/dL; and at 3:00 AM more than 70 mg/dL.



Subcutaneous infusion insulin pump



� For many type 2 diabetics, early and aggressive initiationof insulin therapy has demonstrated beneficial effects.

�

Unlike oral agents, insulin has no upper dose limit andcan be adjusted over time to achieve near-normalglucose levels. Many type 2 diabetics require 0.6 to 1.0U/kg per day. The amount of insulin needed is notrelated to the degree of hyperglycemia but to body

adiposity and other factors of insulin resistance. In moststudies, obese type 2 diabetics require significant dailydoses (100200 units) to achieve near-normal glycemia.

� Type 2 diabetics who benefit most from insulin therapy

are those who demonstrate catabolism with ketonuria,persistently elevated glucose levels despite oral therapy,severe hypertriglyceridemia, uncontrolled weight loss orsevere dehydration with hyperglycemia, or the desire tomaintain near-normal glycemia or induce remission.

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Management of Anesthesia