Geriatric anaesthesia

anaesthesia in elderly patients

1. anaesthetic management of geriatric patient for elective surgery GUIDED BY: DR.SHEETAL PRESENTED BY : DR. NANDINI DESHPANDE

2. Elderly-fastest growing population globally. India →census registrar general of india from independence 18 million→78 million in 2001→150 million in mid century More than 50% of them require two or more surgeries in lifetime. INTRODUCTION:

3. Related directly to stiffening and decreased destensibility of arterial and cardiac wall. Age related changes include : 1.↑MAP and pulse pressure 2. ↓cardiac output,SV,EF in response to stress 3. Calcification of valves(aortic and mitral)→↑risk of CVS death by 50% 4.↓in compliance of venous system which hinders changes in intravascular volumes 5. Cardiac conduction system →fibrotic changes,making them more prone for arrythmias 6. Impairement of diastolic relaxation→diastolic dysfunction in ageing heart→diastolic heart failure now referred to as Heart failure with preserved ejection fraction ( HFpEF ).SO in patients with clinically evident heart failure EF is preserved in over half. 7.↓arterial elasticity and peripheral sclerosis 8. ↑sympathetic nervous system activity 9. ↓b receptor stimulation cvs

4. 1.ANATOMICAL: Loss of muscular pharyngeal support→↓in function of pharyngeal and laryngeal function Loss of ciliary function Barrel chest deformity Flattening of diaphgram Chostochondral joint calcification making chest less compliant RS:

5. 2.PHYSIOLOGICAL: ↑incidence of upper airway obstruction→more prone to have apnea and airway obstruction in RR Loss of elastic tissue-more airways collapse during expiration leading to VP mismatch Volume of pulmonary vascular bed ↓→↑in pulmonary vascular resistance by 80% Impaired response to hypoxia,hypercapnia and mechanical stress→more sensitive to depressant effects of opioids and BZDs Loss of elastic recoil+ ↓ surfactant→increase in lung compliance VC ↓ and RV↑ FEV1 decreases by 6-8%/decade Hypoxic pulmonary vasoconstriction is blunted

6. At rest elderly have to workharder because of less compliant chest wall Ventilatory response to hypoxemia and hypercapnia are decrease so ABG monitoring would be more reliable sign in assesing respiratory function Post op age associated muscular weakness will reduce their ability to cough forcibly and remove secretions thus chances of post op pulmonary complications are high ANAESTHETIC IMPLICATIONS:

7. ↑ in threshholds for virtually all forms of perception i.e vision,hearing,touch,sense of joint position,peripheral pain due to in 1.reduction in electrical activity 2.attrition of afferent conduction pathway peripheral nervous system and spinal cord ↑ in number of cholinergic receptors at end plate and surrounding areas compensate for age related decline in number and density of motor end plate units.→doses of competitive blockers is not reduced PERIPHERAL NERVOUS SYSTEM AND NEUROMUSCULAR FUNCTION

8. ↓sensitivity of baroreceptor→orthostatic hypotension and syncope ↓no of receptors,reduced affinity of agonist molecules e.g ↓ability of b adrenergic agonists to enhance velocity and force of cardiac conduction Thermoregulation is affected→↑heat loss and↓ heat tolerance making them vulnerable to hypothermia and heat stroke AUTONOMIC NERVOUS SYSTEM:

9. Brain size↓→cerebral blood flow and oxygen consumption ↓ Continual loss of neuronal substance→↓ dopamine,norepinephrine , tyrosine,serotonin → depression,loss of memory and motor dysfunction CNS

10. ↓renal mass-↓in glomeruli and nephrons by 40% Renal blood flow ↓approx 10% /decade after 40 years→↓GFR Serum creatinine level →poor indicator of GFR Alterations in response to abnormal electrolyte concentration→renal capacity to conserve sodium↓→fluid and electrolyte status should be carefully monitored 1/5 th of geriatricperianesthetic surgical mortality due to accute renal failure URINARY SYSTEM

11. Characterised by gastric acidity ↓colon motility and anal function→constipation Fecal impaction,fecal incontinence HEPATIC SYSTEM: Liver tissue ↓ by 40%→↓hepatic function→delayed drug metabolism and earlier saturation of metabolic pathways GIT:

12. Loss of skeletal muscle(↓in lean body mass) ↓TBW due to ↓ in intracellular water ↑ in percentage of body fat BODY COMPARTMENTS:

13. Glucose intolerance,decresed thyroxin production or clearance,decreased production of renin,aldosterone and testosterone,and increased plasma conc of ADH Leads to DM,thyroid dysfunction,↓sodium retention,↑potassium absorption and osteoporosis ENDOCRINE SYSTEM:

14. plays a significant part in reducing postoperative complications Detailed medical history, physical examination, laboratory investigations and an assessment of surgical risk should be focussed Informed Consent History and Nutritional status prior medical and surgical conditions history detailed medication list →multiple drug therapy. Physical Examination:regarding hydration, nutrition, blood pressure, pulse irregularities,preoperative mental status Preoperative Evaluation

15. directed towards identifying physiologic deficits and comorbid conditions that may increase the chances of postoperative complications Various comorbid conditions that should be predicted in elderly are as follows: 1.CVS: a. Hypertension:1.DBP >110 mm Hg requires control b. CHF:1.H/O chronic CHF → established predictor of adverse perioperative cardiac events. 2. Levels of BNP may be used to predict outcome Systemic Evaluation

16. C. Arrhythmias:▪ sinus node cells are reduced ▪risk of bradycardia and sick sinus syndrome ▪AF is too high D. Diastolic Dysfunction: ▪ECG findings or ejection fraction are normal ▪cardiac output does not increase with stress and CHF may be precipitated with atrial fibrillation . 1.CVS:continued…

17. 2. Diabetes Mellitus: stress of surgery will increase hyperglycemia discontinue the oral hypoglycemic regimes during the preoperative preparation start insulin regime American Diabetic Association (ADA) recommends:▪pre prandial blood glucose levels between 80 – 120 mg/dl, ▪bed time concentration between 100 – 140 mg/dl and ▪ haemoglobin A1C levels < 7%.

18. 3. Pulmonary disease: Patients with active pulmonary disease (bronchial asthma, COPD) should undergo vigorous preoperative management and optimization before subjecting them for surgery Smoking:A /E→▪functional anaemia from carboxyhemoglobin , ▪ increased airway complication due to hyper reactive airway, ▪ bronchospasm , ▪ atelectasis

19. 1.ATYPICAL PRESENTATION OF DISEASE: ▪Not infrequently,accute illness →atypical presentation. eg,appearance of pneumonia→uncharacteristic features as confusion,lethargy and general deterioration of condition. 2.POLYPHARMACY: ▪ Occurs in 61% of acutely hospitalised older patients SOME SPECIAL PERIOPERATIVE CONSIDERATIONS FOR OLDER PATIENT:

20. 3.MALNUTRITION,IMMOBILITY, AND DEHYDRATION: ▪among accutely hospitalized older patient prevalence of malnutrition is 52% 4.CHRONIC PAIN:occurs in 25-50% of community dwelling older persons

21. Preoxygenation: ▪desaturation occurs faster in older patients ▪8 deep breaths of 100% oxygen within 60 seconds with an oxygen flow of 10 L/min Induction of Anaesthesia: ▪ Use of aspiration prophylaxis and rapid sequence intubation (RSI) ▪Concurrent use of propofol , midazolam opioids , increase the depth of anaesthesia ▪Hypotension is very common ▪Peak effects of drugs administered is delayed:midazolam 5 min, fentanyl 6-8min, and for propofol 10 min. Intraoperative management

22. 1.THIOPENTONE SODIUM: ↓in lean body mass→reduction in vd→high plasma concentrations→↑sensitivity Induction doses about 85% of younger patients 2.PROPOFOL: -smaller central compartment and↓vd -reduced clearance→induction dose(1.7mg/kg) maintainence dose reduced by 30-50% CHANGE IN PHARMACOLOGY OF SPECIFIC DRUGS:

23. 3.BENZODIAZEPINES: Midazolam,lorazepam,diazepam have comparable protein binding and vd High clearance of midazolam makes it an attractive alternative 4.OPIODS: Twice as potent in elderly 50% reduction in doses Shorter acting opiods i.e fentanyl,alfentanil remifentanyl are better choices

24. 5.MUSCLE RELAXANTS: No of Ach receptors at NMJ and their sensitivity to NDMR not altered. Hence dosage required to block NMJ is unaltered Dereased hepatic and renal blood flow and function responsible for prolonged action 6.INHALATIONAL AGENTS: (MAC) of all inhalational agents is reduced by about 4–5% per decade above 40 years of age ↓ MAC leads to rapid induction Recovery prolonged due to larger vd and ↓hepatic clearance and↓pulmonary gas exchange

25. INTRA OP HYPOTHERMIA: Elderly→ higher risk of becoming hypothermic because of anaesthetic induced altered thermoregulatory mechanisms and low BMR Prepping preoperatively and cleaning postoperatively with warm solutions, using warming systems, warming IV fluids, keeping the environmental temperature warmer, Covering the patients with blankets before and after the surgery

26. Difference in outcome between regional and general anaesthesia in older patients is not clear Yet some specific benefits of regional anaesthesia may provide some benefits; 1.affects coagulation system by preventing post op inhibition of fibrinolysis →↓incidence of DVT or pulmonary embolism 2.haemodynamic effects may be associated with ↓blood loss in lower extremity surgeries 3.does not necessitate instrumentation of airway→lowers risk of hypoxaemia 4.opiate sparing effect REGIONAL VS GENERAL ANAESTHESIA:

27. 1.FOR NEURAXIAL BLOCKS: size of epidural space is reduced permeability of dura is increased volume of CSF decreased narrowing if intervertebral space and osteophyte growth→decreases transforaminal escape of local anaesthetics producing an increased level of block onset of analgesia with epidural anaesthesia is more rapid due to increased permeability of extraneural tissues to local anaesthetics

28. 2.FOR LOCAL ANAESTHESIA/PERIPHERAL NERVE BLOCKS: decrease in conduction velocity of peripheral nervesdue todecrease in inter schwann distance decreased no of axons in peripheral nerves

29. 1.OXYGENATION: Increase in CO and ventilation to satisfy O2 demands does not occur readily Diffusion hypoxia may be more prolonged and serious 2.POSTOPERATIVE ANALGESIA: Poor pain control can lead to slow recovery and life threatning complications Pain →risk factor for POCD NASAIDs and paracetamol by iv,im,oralor rectal routes.but should be avoided in >70 years of age,renal dysfunction,suffered hymodynamic instability. Peripheral blocks when feasible shouldbe used POST OPCOMPLICATIONS:

30. 3.HAEMODYNAMICS: a.HR→may not be a reliable indicator ofhypovolemia in elderly due to reduced no of adrenergic receptors,decreased efficacy ofbaroreceptor reflexes and administration of concomitant b-blockers hypotension may exist without tachycardia. b.HYPOTENSION→safer to administer volume in small intermittent boluses watching response of CVP,BP and urine output c.administration of hypotonic fluids(5%dextrose etc) may result in hyponatraemia and low serum osmolalilty resulting in cerebral oedema d.ARRYTHMIAS:may represent disturbances due to pre existing cardiac disease,hypokalemia,hypomagnesemia,hypocalcemia,hypoxiaor hypercarbia . may indicate MI(esp. VPCs>5/ min,bigeminy,ventricular tachycardia,heart blocks other than first degree)

31. 4.HYPOTHERMIA: Manifests as altered mental status delayed recovery from anaesthesia sluggish DTRs slow respiratory pattern Leads to metabolic disturbances ↓liver and kidney perfusion induce coagulopathy Management:mild→warming with blankets and warm rooms severe:active warming methods such as use of warm iv fluids and surface warming with continuous core temperature monitoring

32. Post-Operative Delirium (POD) • DSM-MS IV: A change in mental status, characterized by: – a prominent disturbance of attention and reduced clarity of awareness of the environment; an acute onset, developing within hours to days, and tends to fluctuate during the course of the day.

33. Main clinical features • Acute onset • Fluctuating course • Inattention • Disorganized thinking • Alteration in consciousness • Cognitive deficit (memory, orientation, executive functions) • Hallucinations • Psychomotor disturbances • Lethargy (hypoactive delirium) • Agitation (hyperactive delirium) • Alterations of sleep-wake cycle • Emotional disturbances

34. Postoperative Cognitive Dysfunction (POCD) • Deterioration of intellectual function presenting as impaired memory or concentration. • Not detected until days or weeks after anesthesia • Duration of several weeks to permanent • Diagnosis is only warranted if: – corroborated with neuropsychological testing – evidence of greater memory loss than one would expect due to normal aging

35. • POCD – Common in all age groups at hospital discharge (33- 44%) – 3 months after surgery the POC incidence was: • 4-5% in those younger than 65 • 13% in adults older than 60 years particularly on those with lower educational achievement • Associated with increased one-year mortality