Diabetes mellitus and perioperstive mgt.pptx

ppt explaining perioperative management of diabetes mellitus

1. Diabetes Mellitus and Periop Management Presenter :-DR PRIYA JAIN Moderator :-DR SUMIT AGARWAL

2. Definition Diabetes is a metabolic disorder of multiple etiology characterised by chronic hyperglycemia with disturbances of carbohydrate,fat and protein metabolism resulting from defect in insulin secretion ,insulin action or both. Common presenting symptoms of DM include polyuria,polydipsia,weight loss,fatigue ,blurred vision,frequent superficial infections .

3. Diagnosis According to american diabetes association:- Fasting plasma glucose value >126 mg/dl Random blood sugar>200 mg/dl 2 hr post oral glucose >200mg/dl during an OGTT HbA1c >6.5%

4. Impaired glucose tolerance It is also called prediabetes hbA1c -5.7-6.4% Fasting glucose-100-125mg/dl Oral glucose tolerance test-141-199mg/dl

5. Epidemiology India is the “diabetes capital of the world”. About 77 million are considered to be pre diabetic and over 60 million already diagnosed with diabetes. Projected to at least double by 2030.

6. Classification Characterised by insulin deficiency and a tendency to develop ketosis Responsible for 90% of all cases of dm Endocrinopathies Drug or chemical induced Genetic defects in insulin action Type 1 DM Type 2 DM Other specific types

7. Criteria for testing for diabetes in asymptomatic adults Testing should be considered in overweight or obese(BMI >25kg/m2) adults who have 1 or more of the following risk factors: First degree relatives with diabetes Physical inactivity hypertension Other clinical conditions associated with insulin resistance Pcod Prediabetics (Hba1c>5.7%)

8. Acute effects of hyperglycemia Dehydration and electrolyte disturbances Acidaemia Fatigue ,weight loss and muscle wasting Poor wound healing and impaired wound strength Diabetic ketoacidosis coma Hyperosmolar non-ketotic coma

9. Chronic effects of hyperglycemia Microvascular - proliferative retinopathy, diabetic nephropathy Macrovascular - atherosclerosis , coronary heart disease ,cerebrovascular disease Neuropathic - autonomic -diarrhea,urinary incontinence ,postural hypotension ,cardiac denervation Stiff joint syndrome Increased incidence of infections.

10. Other complications Decreased threshold for arrythmias Increased incidence of acute renal failure in perioperative period Decreased ventilatory response to hypoxia and hypercarbia due to autonomic neuropathy Peripheral neuropathy Susceptible to respiratory depression from opioids and sedatives

11. Goals of perioperative diabetic management Avoidance of hypoglycemia Avoidance of marked hyperglycemia Maintenance of fluid and electrolyte balance Prevention of ketoacidosis/hyperosmolar states Return to stable glycemic control as soon as possible

12. Factors affecting periop management Type of diabetes medication End organ changes Level of glycemic control Urgency of surgery Nature of surgery

13. Preanaesthetic evaluation Severity and type of disease Anti diabetic medication Control of blood sugar Associated complications of dm Airway assessment Assessment of ANS Nature of surgery

14. Pre op evaluation To assess history/examination Investigation 1)blood sugar control hypo/hyperglycemic episodes, hospitalisation Blood sugar- f& pp hba1c 2)nephropathy h/o HTN, edema,recurrent UTI Urine- R/E , RFT 3)cardiac status h/o Angina /MI, exercise tolerance Resting ecg, cxr, ECHO,TMT 4)PVD h/o intermittent claudication,non healing ulcer USG doppler

15. Pre op evaluation To assess history/examination Investigation 5)Retinopathy h/o visual disturbances Fundus examination 6)ANS Early satiety, orthostatic syncope,abdominal distension Postural change in BP, HR variability with exercise 7) metabolic &electrolyte h/o starvation,infection ,sign of dka ABG, Urinary ketone,sr electrolytes 8)airway Stiff joint syndrome, prayer sign Xray cervical spine ap&lateral

16. Diabetic autonomic neuropathy Autonomic dysfunction develops in individuals with long standing type 1 or type 2 diabetes involving cholinergic ,noradrenergic systems. It can be subclinical or clinical. Clinical symptoms and signs:- Cardiovascular :- resting tachycardia , exercise intolerance, orthostatic hypotension GI - esophageal dysmotility,gastroparesis,constipation,diarrhoea,faecal incontinence Genitourinary :-neurogenic bladder , erectile dysfunction Metabolic :- hypoglycaemic unawareness

17. Stiff joint syndrome Long standing type 1 diabetics are at risk for this syndrome,manifested by joint rigidity due to glycosylation of collagen(most significantly affecting joints involving airway such as tempero mandibular,atlanto occipital and cervical spine joints). Limited neck mobility may result in a difficult intubation and should be identified before airway manipulation. A positive “prayer “sign (inability to approximate their fingers and palms while pressing their hands together with the fingers extended) and palm printing have been reported to identify patients with stiff joint syndrome

18. Test for autonomic neuropathy 1)HEART RATE VARIABILITY- in response to a) deep breathing - patient lies quietly and breathes deeply at a rate of 6 breaths /min ( a rate that produces maximum variation in heart rate) while a monitor records difference between maximum and minimum HR Normal variability: >15 beats /min Abnormal variability:<10 beats /min b) standing

19. Test for autonomic neuropathy 1)HEART RATE VARIABILITY- in response to a) valsalva maneuver- Supine patient connected to an ECG monitor Forcibly exhales into the mouthpiece of a manometer,exerting a pressure of 40 mm hg for 15 seconds with an open glottis Sudden transient increase in intra thoracic and intra abdominal pressures,with a characteristic haemodynamic response

20. The response has four phases and in healthy individuals observed as follows:- a) phase 1- transient rise in BP and fall in HR b)phase 2- early fall in BP with a subsequent recovery of BP later in the phase accompanied by an increase in HR c) phase 3- BP falls and heart rate increases with cessation of expiration d)phase 4- BP increases above the baseline value The valsalva ratio is determined from the ECG tracings by calculating the ratio of the longest R-R interval after the maneuver to the shortest R-R interval during or after the maneuver Ratio <1.2 is abnormal

21. Clinical manifestation of neuropathy Orthostatic hypotension -fall in BP(>20 mm hg for systolic or>10 mm hg for diastolic BP)in response to postural change,from supine to standing. Exercise intolerance- decreased cardiac output in response to exercise in individual with autonomic neuropathy

22. Anaesthetic importance of autonomic neuropathy Increased chances of aspiration on induction Exaggerated response to intubation Profound hypotension is seen under neuraxial blockade Short QT interval associated with neuropathy may result in serious cardiac arrhythmias. More susceptible to depressant effects of anaesthetic drugs and unexpected cardiac or respiratory arrest is more common. Increased risk of perioperative cardiac disease

23. Preop fasting Atleast 6 hours for solid foods Patients with gastroparesis, 12 hours may be needed. Such patients are given H2 blockers(ranitidine) and prokinetics(metoclopramide) When fasting exceeds 8-10 hours then insulin-glucose infusion has to be started to prevent catabolism. C heck morning FBS,electrolytes,urine sugar and ketones

24. General principles Avoid hypoglycemia as this can cause irreversible cerebral damage Avoid severe hyperglycemia to minimise dehydration and metabolic upset First on the operating list to shorten the perioperative fasting period and potentially allow normal oral intake later that same day Iv fluids:- Ringer ‘s lactate- lactate undergoes gluconeogenesis in liver and may complicate blood sugar control. Can be used safely with monitoring of sugar Normal saline- infusions in large volumes increase risk of hyperchloremic acidosis. Thus there is no ideal solution

25. Patients on OHA(without insulin) Omit OHA 24-48 hours before surgery Chlorpropamide to be stopped 3 days prior as it is long acting, substitute with a shorter acting sulphonyl urea) Restart OHA when patients are able to resume normal meals Indications of shift to insulin preoperatively - Poorly controlled DM Well controlled DM for major surgery Type 1 DM having minor or major surgery

26. Patients on insulin Patients who take both evening and morning doses of insulin should take their usual doses of short acting insulin, but reduce their intermediate or long acting insulin dose by 20% the night before surgery On the morning of surgery ,they should omit their short acting insulin and reduce the intermediate or long acting dose by 50% ( and take this only if the fasting glucose >120 mg/dl) Premixed insulin:- reduce their evening dose prior surgery by 20% and hold insulin completely on the morning of procedure

27. Surgical stress response

28. Intraoperative glycemic management Intraop hyperglycemia (>180mg/dl) as well as relative normoglycemia(<110mg/dl) both was found to be associated with significant morbidity and mortality. For major surgeries,variable rate iv insulin infusion has been highlighted as more effective American diabetes association(ADA) recommend target glucose level between 140 and 180mg/dl in critically ill patients and in non icu settings,recommend a target fasting glucose of<140 mg/dl and a rbs of <180 mg/dl for patients treated with insulin

29. Pharmacological effects of drugs Decrease secretion of ACTH and cortisol production,when used in high doses during sx Produce haemodynamic,hormonal and metabolic stability Effectively block the entire sympathetic nervous system and the HPA axis,by direct effect on hypothalamus and higher centres. Blocks adrenal steroidogenesis and hence cortisol secretion and decreases hyperglycemic response to sx Benzodiazepines High dose opioids Etomidate

30. Pharmacological effects of drugs Diabetic patients show a reduced ability to clear lipids from the circulation Low dose-hyperglycemia mediated via alpha 2 adrenoreceptors High dose- hypoglycemia mediated through opioid receptors Halothane ,enflurane and isoflurane in vitro inhibit the insulin response to glucose in a reversible and dose dependent manner. Propofol ketamine Inhalationals

31. Pharmacological effects of drugs Succinyl choline should be avoided in patients with extensive peripheral neuropathy due to risk of increased potassium release. Atracurium is preferred in presence of renal dysfunction. Muscle relaxants

32. General anaesthesia and diabetes May have difficult airway Controlled ventilation needed as patients with autonomic neuropathy may have impaired ventilatory control. Aggravated haemodynamic response to intubation. may mask symptoms of hypoglycemia High dose opiate technique may be useful to block the entire sympathetic nervous system and the hypothalamic pituitary axis. Better control of bp in patients with autonomic neuropathy ADVANTAGES DISADVANTAGES

33. Regional anaesthesia and diabetes If autonomic neuropathy is present,profound hypotension may occur Infections may be increased(epidural abscesses more common in diabetes) Blunts increase in catecholamines,cortisol,glucagon and glucose Hypoglycemia readily detectable Metabolic effects of anaesthetic agents avoided Decrease chance of aspiration, ponv,thromboembolism Rapid return to diet and s/c insulin/oha ADVANTAGES DISADVANTAGES

34. Regimens of insulin therapy Variable rate intravenous insulin infusion(VRIII) Tight control regimen Vellore regimen Albert’s regimen Sliding scale

35. Sliding scale regimen

36. Diabetic crisis hyperglycemic Diabetic ketoacidosis Hyperglycemic hyperosmolar state hypoglycemic

37. Diabetic crisis hyperglycemic DKA- blood glucose>250 mg/dl acidosis-ph<7.3 Seum hco3<15 meq/l Serum ketone>7 osmolarity-300-320 hypoglycemic Blood sugar <50 mg/dl

38. Precipitating factors for DKA Infection, sepsis Trauma Stress Missing insulin injections Gi hemorrhage,MI,pancreatitis

39. Diabetic crisis hyperglycemic DKA- blood glucose>250 mg/dl acidosis-ph<7.3 Seum hco3<15 meq/l Serum ketone>7 osmolarity-300-320 hypoglycemic Blood sugar <50 mg/dl

40. Diabetic crisis hyperglycemic DKA- blood glucose>250 mg/dl acidosis-ph<7.3 Seum hco3<15 meq/l Serum ketone>7 osmolarity-300-320 hypoglycemic Blood sugar <50 mg/dl

41. HHS -Management Fluid resuscitation is the mainstay of treatment Due to greater hyperglycemia and hyperosmolarity,these patients are at increased risk of developing cerebral oedema So more gradual(>24 hr) correction of hyperglycemia and hyperosmolarity recommended along with frequent neurological evaluation

42. Hypoglycemia Blood sugar <70 mg/dl Symptoms - tachycardia, tremors,hunger,palpitations followed by neuro symptoms confusion,blurred vision,seizures Stop insulin and give dextrose 20-30 ml 50%dextrose( each mililitre of 50%glucose will raise the blood glucose of a 70 kg patient by approx 2mg/dl Dextrose infusion may be required glucagon(0.5-1.0 mg IM)

43. Post op period Insulin glucose infusions should be continued until the patients can resume an adequate diet Hyperglycemia detected post op in patients not previously known to have diabetes should be managed as if diabetes was present. For type 1 patients, stop the infusion once they are eating and drinking

44. Emergency surgery Little time for stabilisation, but if 2-3 hr available- Correction of fluid and electrolyte imbalance Correct hyperglycemia(start I-G infusion if sugar>180 mg/dl) Treat acidosis Surgery should not be delayed in an attempt to treat ketoacidosis completely if the underlying condition will lead to further deterioration Likelihood of intraop hypotension and arrhythmia more particularly if pt has preop acidosis or hypokalemia Intraop sugar to be monitored more frequently :-atleast hourly

45. Thankyou