Dr. GERTRUDE SIYAKA Consultant Anaesthesiologist Steve Biko Academic Hospital

 Introduction  Normal physiological changes associated with ageing  Pharmacokinetics and pharmacodynamics in the elderly  Pre-operative assessment  Day case surgery  Anaesthesia for orthopaedic surgery  Post operative complications  References

 Life expectancy in US and Europe now yrs  Medical progress most effective in change  Demographical data indicate the elderly most rapidly growing of population  Use of health care services by elderly disproportionately higher than younger patients  Elderly patients now routinely undergo operative procedures

 Ageing a complex multifactorial process  Universal and progressive physiological process marked by declining end organ function, imbalance haemostatic mechanisms, increasing pathologic processes  Theories on numerous and diverse: evolutionary, molecular, cellular and systemic  Include mutation accumulation, programmed cell death, cumulative environmental damage, free radical damage  End result is impaired function and progressive decline

 Age –related changes occur in all organs  1. Cardiovascular system  Main contributor for adverse outcome in peri-operative period  Heart  LV hypertrophy frequently evolves and related to elevated SVR  Cardiac mass increases- concentric hypertrophy  Interstitial fibrosis in myocardium leads to poor contractility

 Stiffness myocardium affects diastolic relaxation as well as systolic contraction  Prolonged systolic myocardial contraction then ensues  LV relaxation time delayed at time mitral valve opening  Early diastolic filling declines  Age related increase in LA volume and contribution to diastolic filling shows importance of “atrial kick”.  Ventricular eccentric hypertrophy and loss wall tension may lead to valve closure deficiency and regurgitant valves

 Aortic valve sclerosis common  CO decreases linearly after 3 rd decade at 1% per year even in healthy individuals  80 yr old will have approx 50% CO compared to when was age 20  CI decreases at 80% per year

 Vasculature  Arteriosclerosis is the hallmark feature  Contributing factors are: hypertension,hypercholesterolemia, oxidative stress and genetic disposition  Arteriosclerosis an irreversible process  CEA and AAA repair most frequently performed procedures in elderly

 Adrenergic sensitivity  Plasma CATS levels after stimuli not been shown to diminish  Blunted B-receptor responsiveness possibly due to down regulation and decreased agonist binding to receptor  Increase in vigil tone  There is 20% loss of HR response during exercise in 75 yr old compared to 25 yr old

 2. Respiratory system  Typical barrel chest appearance results in increased work of breathing and reduced compliance  Loss of elastic recoil within the lung and changes in surfactant production leads to limited maximal expiratory flow  Lung volumes: increase in RV, closing capacity, FRC, TLC (minimal). Decrease in VC  Flow :progressive decrease in FEV1 /FVC  Oxygenation: decrease efficiency in alveolar gas exchange resulting in PaO2and increase alveolar – arterial gradient  Impaired response to hypoxia, hypercarbia and mechanical stress

 3.Renal  Renal mass decreases by 30% by age 80  Renal blood flow and creatinine clearance decrease  Poor electrolyte handling and capacity to concentrate or dilute urine  Excretion of some anaesthetic agents is impaired

 4. Nervous system  Brain weight declines by 10%  Cerebral atrophy common  Cerebral blood supply reduced and vertebrobasilar insufficiency common  Gradual decline in cognitive function, memory and reasoning performance  Confusion common  Altered sleep pattern  Thermoregulation: poor response to hypothermia

 Pharm’kinetics influenced by in plasma protein binding, lean body mass, changes in circulating blood volume and metabolism and excretion of drugs  Lean body mass reduced  Protein binding sites reduced  Decrease in circulating blood volume- higher than expected initial plasma concentration of drugs  Polypharmacy  Elderly more sensitive to anaesthetic agents

 Get medical history, current functional status and medication  ASA status  Lab investigation as appropriate for anticipated surgery and medical issues: CXR,12 lead ECG, FBC, U/E and CT scan as appropriate  Worry about polypharmacy  Enquire about social circumstances  Continue B blockers, but discontinue ACEIs, Digoxin  Premedicate if appropriate

 NO MAGIC BULLETS  Effects of initial dose on single patient highly variable  Smaller doses compared to younger patients  Low threshold for invasive monitoring  Position carefully to avoid pressure and nerve injuries  Avoid hypothermia

 An excellent option for carefully selected pts  Pre-operative evaluation to determine functional reserve, physical status,and rational pre-operative testing but must be done early enough to allow for interventions  Suitable for minimally invasive surgery (eyes, urology) in maximally co-morbid pts  Any anaesthetic technique :LA,RA,GA  Premed as appropriate.

ADVANTAGESDISADVANTAGES  RA provides good post –op analgesia  Peri-op MI less frequent  Oculocardiac reflex less frequent  PONV unlikely  Short stay in PACU  Pts eat,drink earlier  Discharge home earlier  Control IOP limited  Long surgery contraindicated  Need pt co-operation  Pt coughing,movement not avoided  Ventilation not controlled( hypercarbia, hypoxia)

 GA may be needed  Same drugs used but consideration to dosing the elderly  LMA can safely be used but proviso  Manage pain adequately  Consider prophylaxis for PONV

 Number of elderly pts in orthopaedic surgery steadily growing (hip fractures, OA, rheumatoid arthritis)  Elderly pts may have significant organ dysfunction; cardiorespiratory, renal and neurological.  They may be malnourished  No single clear anaesthetic technique. RA preferred  Use of cement during surgery known to be associated with intra-operative morbidities

 Tourniquet use common  Sedation often needed when RA used  DVT prophylaxis necessary for major joint surgery  Antibiotics routinely used but must be given before tourniquet  Blood loss may significant in revision surgery  Neuraxial blockade with opioid provides good analgesia

 Prolonged use of urinary catheters should be avoided  Goal is early and efficient rehab  Central neuraxial blockade reduces surgical stress by blocking nociceptive inputs  Geriatric pts have decreased functional organ system reserve and are thus tolerate surgical stress poorly  RA recommended the elderly and has advantage over GA

 Older pt at risk for complications in peri- operative period due to co-morbid diseases and the ageing process  Cardiovascular complications include MI, dysrhythmias esp. AF, and cardiac arrest  Pulmonary complications: atelactasis, pneumonia  Neurological complications: stroke, POD,POCD.  Post operative delirium(POD): acute confusional state  Post operative cognitive dysfunction(POCD): long term impairment in memory, concentration,language and social integration

 Surgery is now performed in older,sicker elderly patients  Ageing is associated with numerous physiological changes  Surgery not always benign because of high prevalence of co-morbidities  Adjust anaesthetic technique  Aim to minimise peri-operative complications

 Available on request