how to best minimize the effects of anesthesia in the elderly and very elderly patients

Sheila Ryan Barnett, MD Associate Professor of

AnesthesiologyHarvard Medical School

Beth Israel Deaconess Medical Center

Boston, MA

Population

USA

> 65y

>85 y

16,000,000 surgeries per year

60% of patients of general surgeons > 65y

Growth in specialty surgery expected: 35-47%

Frequency of 12 common procedures

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Li et al Anesthesiology 2009; 110: 698-9 US 1999 – 2005

Aging & comorbidities Medications – modifications Medications – to avoid Risk reduction Inevitability

Aging involves physiological changes

AND

The pathophysiology of superimposed disease

Steady Age-related Decline in Organ

Function

> 80y

DISABILITIES COMMON

What is your elderly patient’s functional reserve?

Goal of the preanesthetic assessment

Minor complications poorly tolerated

Vascular stiffening, HTN, loss elasticity Ventricular

• Increased impedance - wall hypertrophy • decreased compliance, atrial dependence

Conduction issues: • Decline in pacemaker cells, increase in atrial ectopy,

& conduction defects Reduction in maximal HR –

• reduced response to catecholamines Increased ischemic heart disease

Diastolic Function

Classification

% LVEF

Normal 37% 54%

Mild to Moderate

57.9% 54.5%

Moderate 3.9% 54%

Severe 1.7% 43%Philip Anesth Analg 2003 ; 97 1214-21

Diastolic E/A : deceleration time / 250 pts /72 y

61.5%

Thorax stiffens:• reduced chest wall compliance & decreased thoracic

skeletal muscle mass = Increased work of maximal breathing

Lung volumes change – reduced reserve volume Decrease in elastic lung recoil – closing volume

increase More V/Q mismatch & greater P(A-a) O2 gradient

Reduction in hypoxic and hypercarbic drive

Increased narcotic-induced apnea Decreased pharyngeal reflexes - ? More aspiration

At age 80 paO2 is about 58 mmHg !

Close to the edge at the start !

• Case controlled study of Spinal surgery patients

• Compared patients with & without Surgical Site Infection (SSI)

• Independent risk factors: – Long surgery OR 4.7 p<0.001– ASA 3 + OR 9.7 p< 0.001– Obesity 4.0 p<0.01– Intraoperative oxygen <50% OR 12 p <0.001

• Potential impact for elderly ?

Maragakis Anesth 2009; 110:556-62

Cortical grey matter attrition – • starts in middle age

Cerebral atrophy – disease vs. aging

Increased intracranial CSF

CBF and auto regulation largely maintained

Postoperative cognitive dysfunction

1. Appreciate reduction in reserve function

2. Understand age related organ changes and the impact of common disease

3. Beware of ‘under-diagnosis’ e.g. DHF & fluids

4. Provide supplemental extra oxygen, (increased risk hypoxemia)

Dose reduction • Pharmacokinetic • Pharmacodynamic

Interval extension

Anesthesiology 2009; 110:1050-1060

What Dose?

Dose response curve flattened in the elderly patient

JR Jacobs et al Anesth Analg 1995; 80:143

25 -50% reduction

50% reduction in initial doses for fentanyl

Significant decrease in pharmacodynamic response

All opioids increased risk apnea & hypercapnia

Increased & delayed hemodynamic impact leading to hypotension

Anesthesiology 2009; 110:1050-1060

“Start low, go slow” Benzodiazepines

• Low dosing with Midazolam to start Opioids

• Beware respiratory depression• Titrate to effect

Reduce inhalation agent Complete reversal of muscle

relaxants

• Anticholinergic side effects – Central: Falls, delirium, cognitive dysfunction– Peripheral : Dry mouth, constipation, confusion

• Anticholinergic Risk Scale – List of drugs with varying anticholinergic

properties – Avoid or limit use if possible

• Beers Criteria – Long acting Benzodiazepines– Multiple medications , many with

anticholinergic properties

• High risk 3 points – Atropine products – Hydroxyzine (Atarax or Visteril) – Diphenyhydramine (Benadryl)– Promethazine (Phenergan)

• Intermediate 2 points – Prochlorperazine (Compazine)

• Low 1 point – Haloperidol– Metoclopramide ( Reglan)

Rudolph Arch Int Med 2008; 168:508-13

Active metabolites normeperidine • Renal excretion• T ½ 14-21 hrs in elderly up to 30 hrs with CRI

Causes myoclonus, twitching and seizures

Associated with delirium in elderly Not recommended: use of meperidine

in patients 75 yrs or older for analgesia is considered indicator of poor care by the Assessing Care of vulnerable elderly.

• Survey of 3000 community dwelling 57-85 y – 81% minimum of 1 prescription drug (PD)– 49% used dietary supplements – 29% used at least 5 PDs

• Among PD users 46% also used over the counter drugs

• 4% at risk of major drug interaction, half with non prescription drugs

• Anti-coagulants most commonly involved

Unknown true impact on the perianesthetic course

Qato JAMA 2008; 300 (24) 2876

1. Avoid meperidine, long acting muscle relaxants & benzo’s and anticholinergic

2. Look for Polypharmacy

Timing of surgery Comprehensive preoperative

assessments Beta Blockade … again

Meta-analysis of >250,000 hip fx pts

Mortality at 30 days and 1 year

When delayed over 48 hours • 41% increase 30 d mortality • 32% all cause mortality

How practical is this?

Shiga et al Can J Anesth 2008; 55:3; 146-154

120 patients >60 y CGA

• ADLs, IADLs (Barhtel Index) , comorbidity, nutrition, MMSE

All undergoing thoracic surgery

17% post op complications

Predictors – • Low Barthel Index • Surgery >300 mins • Dementia – low MMSE

Fukuse Chest 2005; 127:886

400 patients > 70 y Admitted to Intervention Ward

• Assessment, prevention treatment education Assessment day 1,3,7 Delirious patients in the Intervention ward

• Shorter duration: by day 7 30% vs 60% (p 0.001 )

• Shorter LOS: 9 vs 13 days (p 0.001)• Reduced mortality: 2 vs. 9 patients died (p 0.03)

Lundstrom et al JAGS 2005:53:622

Mangano NEJM 1996;335:1713• 100/200 patients received Atenolol

preop and for 7 days• Atenolol group improved survival 6

months & up to 2 y. Diabetes major risk

But later data mixed results with increased stroke and mortality

• Observational study

• 5158 THR/THR patients– 19% Beta blockers

• BB for 7 days (740) • BB DOS & d/c’ed (252) 25%

– No BB (4166)

• Total 1.5% (77) had POMI • BB continued -22 POMI; 7 deaths• BB discontinued -20 POMI; 19 deaths• No BB – 35 POMI; 28 deaths

• Event rate 3% BB vs. 7.9% for d/c’ed BB• In those discontinued beta blockers 2 fold increase in

POMI and death ( OR 2.0)

Van Klei et al Anesthesiology 2009; 111:117-24

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45,370 patients eligible for beta blockade

Vitagliano et al. JAGS 2004: 52:495

1. Careful preoperative assessment is a priority

2. Get to the OR in a timely manner 3. Risk reduction medication – possible

beta blockers 4. Role of blood transfusions (not

discussed)

Unanticipated day of surgery deaths – > 800 000 patients NSQIP - Death rate 0.08% – Older age 60 vs. 67y and males P<0.0001

• Complications increased death rate

• PACU/ICU transfer most unstable

• Opportunity to improve in 31% (chart review )

• Improvement: hypovolemia, MI and transport period

Bishop Anesth Analg 2008 107: 1924-35

Veterans Hospital Data • 26 648 > 80 y• 568 263 < 80 y

30 day mortality 8% vs. 3%, p<0.001 <2% if > 80y undergoing simple procedures

• TURP, IH, TKR, CEA 20% had complications in > 80y Once a complication – 26% vs 4% mortality

Hamel et al JAGS 2005; 53:424

Cardiac events post non cardiac surgery

7700 patients, 83 (1%) Cardiac event 9 independent predictors In patients experiencing a cardiac

event, intraoperative data more likely to show episode of hypotension +/- tachycardia

Kheterpal et al Anesthesiology 2009; 110:58-66

Avoid complications Hemodynamics

Turrentine et al J Am Coll Surg 2006; 203:865Surgical morbidity

Surgical mortality

300 unselected hip fractures All received similar multimodal

anesthesia & defined rehabilitation Outcomes:

• 30 d mortality 13% • >30d 7 more died

Combined mortality 16%

Foss & Kehlet Br J Anaesth 2005; 94: 24-29

47 deaths • 28% (13) unavoidable, terminal cancer

or refused care • 15% (7) probably unavoidable• 34% (16) potentially avoidable ; active

care curtailed• 23% (11) received maximal care ?

Potentially avoidable

Best outcomes if:

Avoid complicationsPreoperative optimization OR without delay (when feasible) ? Beta blockers / transfusions Age appropriate drug dosing Postoperative: pain meds, oxygen