This document provides an overview of geriatric anaesthesia. It discusses the physiological changes that occur with aging and their implications for anaesthesia management. Key points include:
1. Organ systems like the cardiovascular, respiratory and renal systems undergo age-related changes that reduce functional reserve and increase vulnerability to haemodynamic fluctuations.
2. Anaesthetic pharmacokinetics and pharmacodynamics are also altered in elderly patients, requiring lower doses of drugs.
3. Thorough preoperative assessment of medical history, functional status and frailty is important for risk stratification and care planning. Close perioperative monitoring and attention to fluid balance, temperature regulation and delirium prevention are also crucial.
2. AGEING
◦ Aging is a universal and progressive physiologic phenomenon characterized by degenerative
changes in both the structure and functional reserve of organs and tissues.
◦ This provides a safety margin available to meet the additional demands of surgery, healing and
convalescence.
◦ Two important principles of aging are
1) progressive loss of functional reserve in all organ system
2) The extent and onset of these changes vary from person to person
10. Cardiovascular changes
Heart
o Decreased myocyte number
o Thickening of LV wall
oDecrease in conduction fibre density & no. of sinus node cells
Functionally leads to –
oIncreased myocardial stiffness & ventricular filling pressures
oDecreased beta adrenergic sensitivity
o Decreased contractility
11.
12. Vascular
◦ Large arteries dilate
◦ Walls thicken & smooth muscle tone increases, resulting in increase in vascular stiffness with
age
This is related to –
◦ Breakdown of elastin & collagen
◦ Alterations in NO induced vasodilatation
◦ Elevated MAP & pulse pressure
13. ◦ Ventricular compliance
◦ Afterload
◦ Compensatory prolongation of myocardial contraction & the early diastolic time makes the
contribution of atrial contraction to late ventricular filling important
◦ Decrease in compliance of venous system
◦ Meaning:
– Preload sensitive
– Cardiac rhythm other than sinus poorly tolerated
– Response to changes in IV volume is poor (position changes, third space loss or hemorrhage)
14. Anaesthesia Implication
◦ Hypotension and Bradycardia should be kept in mind during induction
◦ For emergency Anesthesia BP up to 180/110 mm of hg should be allowed
◦ Heart Rate up to 50 at rest is allowed for induction
◦ Ejection Fraction up to 45 % is normal for geriatric age group without any symptoms
◦ Use of Beta blockers and Anti platelets in pre operative period gives more cardio stability in old
heart
◦ Old heart can not compensate decrease CO or increase heart rates
15. Changes in ANS
Response to β receptor stimulation
◦ Due to decrease receptor affinity & alteration in signal transduction
◦ Sympathetic over activity leading to desensitization of β receptors
◦ Causes increased peripheral flow demand to be meet by preload reserve
Clincally:
◦ ANS changes lead to more chances of adverse intra operative hemodynamic events &
decreased ability to meet metabolic demands of surgery
◦ CV diseases are superimposed (IHD, CHF, hypertension, arrhythmias).
16. Changes in Renal function & volume regulation
◦ Renal cortical mass decreases by 20‐25% ( by 80 years – ½ of glomeruli)
glomeruli
After 40 years
◦ RBF dec by 10% / decade
◦ GFR dec by 1ml/min/year (140‐age x wt /72x . S Cr . )
◦ Dec renal excretion of drugs
◦ S.Cr.‐unchanged( poor predictor of renal function)
◦ Progressive decrease in creatinine clearance
17. ◦ Functional changes‐ fluid & electrolyte homeostasis is vulnerable.
◦ There are alterations in response to:
-Abnormal electrolyte concentration
- Capacity to conserve Na+ is
-Tendency to loose Na+ with inadequate salt intake & impaired thirst response resulting in
risk of dehydration and Na+ depletion
-Impaired response salt load resulting in Na+ retention & expansion of ECV in perioperative
period
-Ability to concentrate & dilute urine
18. CNS
◦ Brain mass begins to by 50 years & by 80 years 10% of its weight is lost
◦ In brain reserve manifests by
- in functional ADL
- sensitivity to anesthetic medications
- risk for perioperative & postoperative delirium
Neurotransmitter function affected significantly
(dopamine, NE, serotonin ,GABA, A‐ch)
◦ 6% in MAC/ decade after 40 years
◦ Significant cognitive impairment after 85 years
19. Nervous system
Neuraxial
◦ epidural space
◦ volume of CSF
◦ permeability of duramater
◦ Changes in myelinated fibers (dorsal & ventral nerve roots ) & in peripheral nerves
◦ More sensitive to neuraxial & peripheral nerve blocks
20.
21. Thermoregulation & aging
◦ Impaired temperature regulation & heat production hypothermia
Risks of hypothermia are –
◦ MI
◦ Coagulopathy
◦ blood loss
◦ Impaired drug metabolism
◦ Surgical wound infection
Shivering places significant metabolic stress
– May not be tolerated by a patient with borderline cardiac & pulmonary reserve
22. Endocrine system
◦ The average fasting glucose level rises 6 to 14 mg/dL for each 10 years after age 50 yrs
◦ Functional decline in insulin secretion in response to glucose load
◦ Increase Insulin resistance
◦ Even healthy patients may require insulin therapy in perioperative period
◦ Hyperglycemia increase the mortality and morbidity in old age , because of late diagnose of
DM
◦ Accepted level of FBS is between 80 – 120 mg/dl or HbA1C less than 7
◦ Discontinue metformin and sulfonyl ureas night before and day of surgery( due to increase
chance of MI in hypovolemic and reserved cardiac functions in old age)
23. Liver /Gastrointestinal system
◦ 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 decreased
◦ acid production, moderate atrophy of small intestine villi, decreased colon motility
◦ Risk of prolonged postoperative ileus, retention of gastric contents & risk of aspiration
24. Anaesthetic Implications
◦ Drugs cleared by Phase -1 pathways (oxidation, reduction & hydrolysis) are slowly metabolize
because of decreased hepatic blood flow
◦ Drugs whose clearance depends on hepatic blood flow
-ketamine –flumazenil –morphine -fentanyl –sufentanyl –lidocaine
oBeers criteria recommend avoiding Proclorperazine , Promethazine, Metocloprmide
25. Preoperative Assessment
◦ Complete medical history
◦ History
◦ CVS and RS complaints present and past
◦ Routine activities
◦ Mental & Physical status
◦ Dependency
◦ Associated Diseases
◦ Drug history/Polypharmacy
◦ BMI / Nutrition
◦ Past history Op/Ane. experience
◦ Any alternative medicine
◦ Allergy
◦ Social and Family history
Always see for
-Depression
-malnutrition
- immobility
-dehydration
-Denture
-Pace maker
-Any joint replacement
- Any anti depressant Rx
26. ◦ Functional status assessment
◦ Common screening tools –
- Activities of daily living (ADL)‐ day to day self care
- Instrumental ADL ( ) IADL ‐ more complex tests
• APACHE (Acute Physiological and Chronic Health Evaluation) for critically ill patients
• POSSUM (Physiological and Operative Severity Score for enumeration of Mortality and Morbidity) for surgical pts.
27.
28. Frailty
◦ Multisystem loss of physiological reserve, prognostic factor for poor outcome
– Clinical syndrome characterized by Weight loss, fatigue & weakness
– Preoperative stratification of perioperative vulnerability and correlates to increased
mortality, lengthier stay & discharge
-sensitive indicator for the necessity of in-depth conversations concerning complicated risks,
likely outcomes , goals of care and alternatives to surgery
29.
30. ◦ Functional capacity‐ 1 – 10 METs –
◦ Site & invasiveness of surgical procedure ‐
◦ Surgery specific risk
High: Emergent major surgery, vascular surgery, prolonged op with large fluid shifts &/or blood
loss
Intermediate: Intermediate: Head‐neck, intra‐peritoneal peritoneal, intra‐thoracic, orthopedic
surgery
Low‐ endoscopic procedures, cataract
31. ◦ perioperative cardiac risk relies on the evaluation of clinical markers
◦ Patients with multiple risk factors need more extensive evaluation – 2D echo etc.
Major: Unstable coronary syndromes, decompensated CHF, severe valvular disease, significant
arrhythmia
Intermediate: Mild AP, previous MI, compensated CHF, DM
Minor: Abnormal Abnormal ECG, rhythm other than sinus, low functional capacity, h/o stroke,
uncontrolled HT
32. ◦ Preoperative PFT – to optimize respiratory function in patients undergoing major surgery
◦ Look for malnutrition, dehydration, alcoholism, mobility
◦ Consider DVT prophylaxis
◦ Explain need for postoperative ventilation, ICU stay, lines/ tubes
◦ Note presence of dentures, hearing aids , pacemakers
33. Depression
◦ 8‐16% >65 years of age
◦ Predicts greater risk for major adverse cardiac events
◦ Predictor of post operative delirium
◦ Preoperative assessment of mood and cognition is important for baseline data ,when
evaluating postoperative delirium , dementia or depression
◦ Antidepressants should be continued during perioperative period
34. MONITORING
◦ ASA standards for basic anaesthetic monitoring should be followed
◦ Monitor hemodynamic stability , adequate anesthesia & amnesia
◦ Additional monitors to detect changes in oxygenation, ventilation,circulation and temperature
◦ EEG may improve the ability to titrate anesthetic doses
35. Positioning
◦ There is increased risk of nerve , joint and skin injury
◦ Stiff joints , particularly in the cervical spine , hips, and shoulders can prevent optimal patient
positioning
◦ Avoid applying force against resistance to increase joint angles
◦ Geriatric pts have fragile skin and peripheral circulation
◦ Avoid skin tearing ,bruising & extra cushioning to avoid pressure sores
36. General Anaesthesia
◦ Airway management plan must be formed to intubate patient safely
◦ Patients are often edentulous, making mask ventilation more challenging and have decreased
cervical extension impairing laryngoscopy
◦ Vasopressors and fast acting antihypertensives should be available during induction to maintain
safe and adequate blood pressure.
◦ During maintainence and tempered dosing and patience are valuable principles, as elderly
pharmacokinetics and dynamics can delay the return of respiratory function and extubation
37. Neuraxial anaestheisa
◦ As compared to GA , Neuraxial techniques are associated with fewer pulmonary complications
in patients with lung disease
◦ Decreased requirement of sedating medications may decrease the risk of postoperative
delirium
◦ It is not an ideal choice for long surgeries ,patients with anxiety & difficulty lying comfortably in
required position for surgery
38.
39. IV Anaesthetic agents
◦ Geriatric patients require lower doses of intravenous anaesthetics due to altered
pharmacodynamic response and decreased drug clearance
◦ Propofol requires only 50 to 70 percent dosing (bolus or infusion) relative to younger patients
◦ Etomidate is often favorable choice as an induction agent in elderly/pt with cardiac reserve
or hemodynamic instability
◦ Ketamine may be practical primary or adjunct agent in certain circumstances but is rarely used
in due to post operative delirium
◦ The bronchodilatory effects of ketamine is good for patients with reactive airway disease or
hemodynamic instability with CAD
40. Opioids
◦ There is higher risk of opioid – induced apnea, with decreased hypoxic and hypercarbic
respiratory drive to compensate for oversedation
◦ Opioids are more potent due to decreased clearance and increased neurologic sensitivity
◦ Pain should be treated first with non-opioid analgesics then weak opioids
◦ Use of morphine places patients with decreased renal function at risk of apnea
◦ Meperidine increases the risk of postoperative delirium
◦ Fentanyl, Sufentanyl ,Alfentanyl : 50% reduction reduction in dose, minimal changes in
pharmacokinetic
41. Neuromuscular blockers
◦ There is prolong duration of neuromuscular blockade for most agents
◦ In setting of respiratory dysfunction, these changes increase the risk of postoperative
respiratory complications and reintubation
◦ Atracurium , cis-atracurium and mivacurium do not prolong paralysis in geriatric patients due
to elimination by ester hydrolysis or Hoffmann degradation
◦ Complete reversal should be verified before extubation
42. Fluid management
◦ Geriatric patients have poor tolerance for hypervolemia and hypovolemia
◦ Dehydrated patients may benefit from preoperative fluid resuscitation or drinking clear fluids
upto 2 hrs
◦ Fluid overloaded patients may require hospital admission for diuresis to optimize surgical
conditions
◦ Moderate administration of crystalloids or colloids to maintain euvolemia and avoid CHF
exacerbation , pulmonary edema and dilutional coagulopathies
43. Postoperative Delirium and Cognitive
Dysfunction
Risk factors
◦ Cognitive dysfunction
◦ Ho CVA
◦ Depression
◦ Age>70 yrs
◦ Alcohol use
◦ Poor functional status
◦ Electrolytes imbalance
44.
45. ◦ ASA developed the Brain Health Initiative to help postoperative cognitive dysfunction
◦ This platform contains tools and resources for practitioners and medical centres to implement preoperative and postoperative
cognitive assessment preventional guidelines
◦ Perioperative Neurocognitive Disorders (PND) includes
-delirium
-delayed Neurocognitive recovery
-mild/major neurocognitive disorder