EVALULATION AND ANESTHETIC AMANAGEMENT FOR GERIATRIC PATIENT

ANESTHESIA MANAGEMENT OF GERIATRIC PATIENT

1. Evaluation and Anesthesia for Geriatric Patient Surgery Moderator - Dr Anita Presenter - Dr Mallika

2. PREOPERATIVE ASSESSMENT Degree of functional reserve of specific organ system should be assessed History & physical examination Laboratory & diagnostic studies History taking difficult & time consuming Impaired hearing & vision Under report potentially important symptoms

3. PHYSIOLOGICAL CHANGES WITH AGEING

4. Central Nervous System Changes Reduction in brain mass, starts at 50 years 10% reduction in brain weight occurs at 80 years Atherosclerosis of cerebral blood vessels Reduced cerebral blood flow Reduced neurotransmitters: Dopamine, serotonin, GABA, acetylcholine Increased incidence of postoperative delirium and cognitive decline

5. Hepatobiliary and GIT Liver mass  with age There is 20 – 40%  in Liver blood flow- risk of hepatic injury with hypotension Maintenance dose of drugs rapidly metabolized is   acid production, moderate atrophy of small intestine villi, decreased colon motility : risk of prolonged postoperative ileus, retention of gastric contents & risk of aspiration

6. Pharmacological Changes Reduced body mass Reduced total body water Relative reduction in fat Reduced albumin Increased acid glycoprotein Reduced cardiac output Mildly contracted blood volume Reduction in hepatic and renal clearance

7. Also altered drug responses as in: Drugs have more pronounced effect Bolus doses take longer time to act Increased drug interactions Target organs more sensitive to drug level Increased context sensitive half life

8. Preoperative management Continue all medication except OHAs Avoid sedatives, especially benzodiazepines and pethidine Perioperative β­blockade considered Care towards Do not resuscitate orders Optimize preoperative medical status Postpone elective surgery until concurrent illnesses are optimized

9. Neuraxial anaesthesia Time of onset is decreased Spread is more extensive Decreased plasma clearence of local anesthetics especially with repeated dosing & continuous infusion techniques ,hence a reduction in top up dose and infusion rates is mandated Most common used for TURP, herniorrhaphy, gynecological surgeries, hip fractures Requires alert and cooperative patient Advantages: • Reduced chances of DVT, early mobilization • Low incidence of postoperative cognitive decline • Rapid recognition of CNS changes and onset of angina pectoris Low risk of hypoxemia Opiate sparing effect

10. Spinal anesthesia: Difficult spinal due to ligament calcification and laxity Prolonged duration of action due to reduced vascular absorption of LA due to atherosclerosis Profound hypotension on induction due to volume contracted state T8­T10 level acceptable for most cases Epidural anesthesia: More gradual onset of hypotension than spinal anaesthesia Dose required to produce sensory block lesser as progressive occlusion of intervertebral foramina with connective tissue occurs

11. Conduct of General Anesthesia Monitoring - Pulse oximetry, capnography NIBP, ECG Temperature, urine output BP/CVP considered in cardiac patients Neuromuscular monitoring (residual palsy) Positioning Osteoporosis increases chances of positional injuries Intermittently relieve pressure points in long dura­tion of surgeries Positional changes should be gradual as defectives baroreceptor function

12. Induction Smaller induction doses used Difficult IV access due to thin veins and bony deformities Onset of IV induction delayed due to longer brain­ arm circulation time Significant hypotension with induction Difficult mask ventilation in edentulous patients Precautions to prevent aspiration as: • Blunted airway reflexes • Increased incidence of hiatus hernias in elderly ET tube to be used where possible

13. Fentanyl, sufentanyl, remifentanyl, alfentany and morphine: 50% reduction in dosage Thiopentone and propofol warrant 20% reduc­tion in dose Midazolam requires modest reduction in dose at 60 years and 75% reduction in dose at 90 years Vecuronium, rocuronium, cisatracurium and succinylcholine: – Have slower onset of action – Increased incidence of residual paralysis especially if multiple doses used Residual paralysis occurs due to drug accumulation

14. Neostigmine dose increases with age in some studies Decrease in MAC value of volatile anesthetics with age Reduced sensitivity to β­agonists, antagonist and digoxin with age Increased chances of renal failure and GI bleed with NSAIDs Increased hypotension with CCBs, nitrates and diuretics due to volume contracted state

15. Maintenance Reduced MAC value of volatile anesthetics Reduced doses of intravenous drugs Reduced fentanyl, sufentanyl, alfentanyl, remifenta­nyl and morphine requirements by 50% Reduce doses of muscle relaxants as high incidence of residual muscular paralysis Forced air warmers to prevent hypothermia Ventilation Mechanical ventilation with supplemental oxygen preferred to spontaneous ventilation High tidal volume with PEEP used to prevent atelectasis Avoid hyperventilation if patient receiving digoxin to prevent hypokalemia

16. Postoperative Care Early establishment of nasogastric tube feeding Early mobilization, physiotherapy and thrombo­prophylaxis, elastic support stockings Maintain hemoglobin level at 9–10 g% if cardiac disease present Continue oxygen for 24 hours except in minor surgeries Monitor fluid balance and fluid overload

17. Postoperative Analgesia Delirium and cognitive decline hinder pain report­ing by patient More difficulty with visual analog scale rather than verbal/numerical scales Epidural analgesia superior, it also reduces opioid requirements NSAIDs used with caution and reduces opioid requirement Postoperative pulmonary complications are most common Greater incidence of desaturation( 20 – 60% hypoxia) Higher risk for aspiration Progressive decrease in laryngopharyngeal sensory discrimination Dysfunctional swallowing

18. Post operative Delirium Risk varies with surgery, 10% with major surgery,highest risk (35%) – emergent hip surgery 60-80% - in ICU patients Acute confusional state Fluctuating level of attention & cognitive skill Disorientation Disorganized thinking Most often short lived (24hrs), can be persistent Associated with  hospitalization ,functional recovery, mortality Manage reversible risk factors If agitated – haloperidol is useful,  severity & duration of delirium when used prophylactically

19. Post operative cognitive dysfunction Criteria for POCD are based on changes between pre & postoperative scores on a set of neuropsychological tests, evaluating a broad range of cognitive domains Long time decrease in mental abilities (memory, attention, executive function, speed of processing) - first days to weeks after surgery Chronic POCD is important to identify- frequent cause of 1 year mortality POCD after major non-cardiac surgery is reversible, may persist in 1% patients No well defined anesthesia practice is there to prevent POCD No specific treatment is available

20. Summary Preoperative screening recommendations and guidelines for older patients can provide a useful starting point to evaluate and optimize care. Some important geriatric specific areas that are amenable to screening include: cognition, frailty, depression, and polypharmacy. Best intraoperative practices follow from an understanding of geriatric physiology and aware- ness of medications which are contraindicated in the older population. Postoperative care tailored to the needs of high-risk adults may benefit the highest risk patients such as palliative care consultation and delirium prevention units.