Anaesthesia for the Over 75s. Chris Edge

Transcription

1 Anaesthesia for the Over 75s Chris Edge

2 Topics to be Covered Post-operative cognitive management Morbidity and mortality General anaesthesia a good idea or not? Multiple comorbidities and assessment of risk Should we adopt a multidisciplinary approach in the management of these patients?

3 Post-Operative Cognitive Management Must distinguish between: Delirium Acute onset of disturbed mental function Common in hospitalized, elderly patients Time course may be short Alteration of consciousness, visual hallucinations, anxiety, distress Dementia Associated with chronic organic brain syndromes Irreversible pathology Associated with failure of cholinergic transmission Global deterioration of cognitive ability in the absence of clouding of consciousness Postoperative Cognitive Dysfunction

4 Postoperative Cognitive Dysfunction - I Two definitions, one useful, the other Deterioration in performance in a battery of neuropsychological tests that would be expected in <3.5% of controls Long-term, possibly permanent, disabling deterioration in cognitive function following surgery It may be the difference between a person capable of independent life and one who is not

5 Postoperative Cognitive Dysfunction - II Studies: 1200 patients > 60 yo non-cardiac surgery in ISPOCD1 study [1]: Incidence of POCD ~25% at 1 week; 10% incidence at 3/12 postoperatively; 1% had unresolved POCD up to 2y postoperatively; Older patients had higher incidence; those over 80 had incidence of ~30% (but small group); Sepsis did NOT affect outcome at 3/12, neither did hypotension; Spinal anaesthesia did NOT protect against POCD. Age is an independent risk factor for POCD [1] Moller JT et al Lancet 1998;351:857-61

6 Predisposing Factors: Early POCD Increasing Age GA rather than RA Duration of anaesthesia Reoperation Postoperative Infection Postoperative Cognitive Dysfunction - III Late POCD Increasing Age Possible Intraoperative Causes: Emboli especially cardiac surgery Biochemical disturbances e.g. hyponatraemia but no evidence that perioperative hypoxaemia or hypotension is associated with POCD

7 Anaesthesia and Alzheimer s Disease (AD) Consensus statement published in 2009 [3] Risk factors for POCD may overlap with those for AD Controversial as to whether CABG is associated with higher risk for AD POCD and dementia more common after cardiac than major non-cardiac surgery [4] [3] Baranov D et al Anesth Analg 2009;108: [4] Rasmussen LS Best Pract Res Clin Anaesthesiol 2006;20:315-30

8 Morbidity and Mortality Several studies [5-8] in patients > 70 yo having non-cardiac surgery have shown: ~6-8% mortality at 30 days; 30-40% complication rate; What preoperative factors are associated with mortality in older patients? [5] McNicol L et al Med J Aust 2007;186: [6] Tan KY et al World J Surg 2006;30: [7] Hamel MB et al J Am Geriatr Soc 2005;53:424-9 [8] Liu LL, Leung JM J Am Geriatr Soc 2000;48:405-12

9 Preoperative Factors and Mortality - I Age an independent risk factor [7]: For every year over age 70, risk of 30 day mortality increases by ~10%; This implies risk doubles between 70 and 80; risk doubles again between 80 and 90. ASA [5]: From ASA 1,2 onward the risk of 30 day mortality rises by a factor of ~2 for each increase in ASA status.

10 General Anaesthesia (GA) A Good Idea or Not? Choice between local, regional, or GA Local or regional techniques should be considered where possible (NCEPOD), and taking into account patients wishes Many patients do not wish to be awake during surgery even if careful explanation is given to them e.g. don t want to hear noise of drill/saw etc.

11 Choice of General Anaesthetic Evaluation of different anaesthetic regimes has not been studied in relation to POCD in the elderly Recent study [9] has compared xenon to propofol in abdominal/urological surgery No difference in POCD between two study groups, but complicated by use of etomidate during denitrogenation [9] Höcker J et al Anesthesiology 2009;110:

12 Helpful Hints for Surgeons A 30 minute increment in operative duration increased odds of mortality by 17% in patients > 80 y [10] Most experienced surgeons should operate on the older age groups Another predictor of morbidity in the 80+ age group is emergency operation [9] with odds ratio of 5.6 for cardiovascular complications [10] Turrentine FE et al J Am Coll Surg 2006;203:865-77

13 Postoperative Complications - I Perioperative inflammation [5]: 20% of patients > 70 y old who developed Systemic Inflammatory Response Syndrome (SIRS) died by day 30; Patients developing SIRS three times more likely to die than those who didn t develop systemic inflammation May be possible to minimize inflammation using statins

14 Postoperative Complications - II Acute renal failure (ARF): Defined as > 20% increase in preoperative creatinine 16% of patients who developed ARF died by day 30 (more than double normal 30 day mortality) No single international definition of ARF, but suggestion that have an increase in creatinine of > 50% or absolute increase of > 26.4 μmol/l will probably give a stronger association with mortality No clear strategies for preventing postoperative renal impairment [11] [11] Sear JW Br J Anaesth 2005;95:20-32

15 Postoperative Complications - III Unplanned ICU admission is strong predictor of 30 day mortality in patients > 70 yo (20% died) [5] Another study [12] of patients > 80 yo in UK found 42% mortality after unplanned ICU admission and 21% after planned admission Similar results [13] in Netherlands for patients > 80 yo (51% and 15% respectively) 1 year mortality in this study was 62% and 22% respectively; 1 year mortality in unplanned ICU group greatly exceeded expected 1 year mortality for that age [12] Ford PN et al Br J Anaesth 2007;99:824-9 [13] de Rooij SE et al Intensive Care Med 2006;32:

16 Management of the Elderly Surgical Patient - II Orthopaedic/geriatric comanagement of hip fractures associated with 20% decrease in complications and 3% decrease in mortality [14] Other studies have found decrease in time of admission to surgery (38 h to 24 h) and a decrease in hospital stay (10.5 to 8.5 days) [15,16] Comanagement not associated with fewer complications or decreased mortality at 30 days or 1 year [16] [14] Huddleston JM et al Ann Intern Med 2004;141:28-38 [15] Phy MP et al Arch Intern Med 2005;165: [16] Batsis JA et al J Hosp Med 2007;2:219-25

17 Management of the Elderly Surgical Patient - III Better detection of problems on the ward might occur with Critical Care Outreach teams An all patient study [17] detected a relative risk reduction of 57.8% due to decreases in cases of: Respiratory failure; Acute renal failure; Stroke; Severe sepsis. Long-term follow-up has shown a reduction in mortality at 1 year and 4 years [18] A conclusive, randomised, controlled trial is unlikely to occur in elderly patients [17] Bellomo R et al Crit Care Med 2004;32: [18] Jones D et al Crit Care 2007;11:R12

18 Actuarial Life Table for Men 50/100 Number of additional years that 50 out of 100 men will live for Risk 1/12 Risk of dying within next month is 1 in Age 50/100 Risk 1/

19 50/100 Number of additional years that 50 out of 100 women will live for Risk 1/12 Risk of dying within next month is 1 in Actuarial Life Table for Women Age 50/100 Risk 1/