Transcript Preoperative Assessment in the Older Adult

Preoperative Assessment in
the Older Adult
Lisa Caruso, MD, MPH
Section of Geriatrics
Boston University Medical Center
Goals
• To review the most common physiologic
changes in the elderly which may impair
one’s ability to compensate for operative
stress
• To describe the purpose of the
preoperative assessment
• To provide strategies to minimize
operative risks
Cardiovascular System
• Changes in “mechanics”
– Decrease in myocytes, increase in
collagen resulting in decreased compliance
– Autonomic tissue replaced by collagen
resulting in conduction abnormalities
– Decreased compliance of vascular system
leading to increased systolic blood
pressure with resulting ventricular
hypertrophy
Cardiovascular System
• Changes in “control mechanisms”
– decreased responsiveness to
catacholamines due probably to impaired
receptor function
– decreased heart rate response to changes
in circulatory volume may lead to
congestive heart failure or hypotension
(CO=SV x HR ==>preload dependency)
Pulmonary System
• Reduced chest wall compliance resulting in
– increased work of breathing
– reduced maximal minute ventilation
• Reduced respiratory response to hypoxia
by 50% (? Due to impaired chemoreceptor
function)
• Decreased ciliary function
• Reduced cough and swallowing function
Neurologic Changes
• Decrease in cortical gray matter, neuronal
volume, complexity of neuronal connections,
synthesis of neurotransmitters
• Neuronal loss and demyelination occur in the
spinal cord resulting in changes in reflexes and
reductions in proprioception
• Vision and hearing loss make information
processing more difficult
Renal Changes
• Decline in renal blood flow--10% per
decade after age 50
• Old kidney has difficulty
– maintaining circulating blood volume
– with sodium homeostasis
– removing excess acid
– adjusting to hypovolemia, hemorrhage, low
cardiac output and hypotension
• Renal insufficiency may not be appreciated
Adverse Drug Reactions (ADR)
• Decrease in lean body mass with increased
proportion of body fat
• Decreased protein binding of certain drugs
• Alterations in renal, CV, hepatic function
may change drug concentrations and their
duration of action
• ADR’s increase with number of drugs
administered and linearly with age
Preoperative Assessment-Purposes
• Not just for “clearance”
• To identify factors associated with
increased risks of specific complications
related to a procedure
• To recommend a management plan to
minimize these risks
Cassel CK, Leipzig RM, Cohen HJ, et al. Geriatric Medicine: An
Evidence Based Approach, 4th ed. New York: Springer; 2003.
Preoperative Assessment-Components
•
•
•
•
Functional Assessment
Cognitive Assessment
Nutritional Assessment
Review of advance directives
– whether and when to withhold or withdraw
support
Functional Assessment
• American Society of Anesthesiologists
(ASA) score
– Class I A normal healthy patient for elective operation
– Class II A patient with mild systemic disease
– Class III A patient with severe systemic disease that
limits activity but is not incapacitating
– Class IV A patient with incapacitating systemic
disease that is a constant threat to life
– Class V A moribund patient that is not expected to
survive 24 hrs with or without the operation
Functional Assessment
• Exercise capacity
– “inactive” defined as inability to leave the
home on one’s own at least twice per week
– increased CV risk in patients unable to
meet a 4-MET demand during most daily
activities
• Activities of Daily Living
– Correlated with post-op morbidity and
mortality
Cognitive Assessment
• Not done uniformly
• Dementia is a major predictor of post-op
delirium
• Use of Mini-Mental State Exam or
orientation and recall testing
• Much potential for future research
Nutritional Assessment
• Poor nutrition is a risk factor for
– pneumonia
– poor wound-healing
– 30-day mortality
• Hypoalbuminemia (<3.3mg/dL)
– increased length of stay
– increased rates of readmission
– unfavorable disposition
– increased all-cause mortality
Corti M. Serum albumin level and physical disability as predictors of mortality
in older persons.JAMA 1994;272:1036.
Strategies to Minimize Risk
• Routine screening is low yield
– preop testing should be based on the type of surgery
• Manage hypertension
– lower blood pressure to under 180/110
• In patients with dementia, consider placement of
epidural to control pain without sedation thus
minimizing risk for delirium
• Avoid long periods without nutrition
– little evidence, but should try to improve nutritional
status prior to elective surgery
Strategies to Minimize Risk
• Perioperative use of ß-blockers
– Mangano, et al., NEJM 1996, RDBPCT
– In patients with or at risk for CAD, does IV
atenolol decrease periop CV morbidity and
increase overall survival?
– Cardiac RF included: age > 65, hypertension,
smoking, cholesterol > 240, and diabetes.
– 200 pts enrolled; IV atenolol 10 mg given 30
min prior to surgery, 50-100 mg bid POD 1-7
– 192 followed for 2 yrs
Strategies to Minimize Risk
Two years
Overall
mortality
Placebo
21%
Atenolol
10%
RRR
52%
ARR
11%
NNT
9
Event-free survival after hospital discharge at 2 years
was 68% in the placebo group and 83% in the
atenolol group (p=0.008).
Not clear yet if age alone is an indication for use of ßblockers in perioperative period.
Strategies to Minimize Risk
• Diabetic Postoperative Mortality and
Morbidity (DIPOM) study
• Perioperative Ischemic Evaluation
(POISE) trial
• Metoprolol after Vascular Surgery
(MaVS) trial
Http://www.medscape.com/viewarticle/494679
Reuben DB, et al. Geriatrics at Your Fingertips 2005, 7th edition. New York, American
Geriatrics Society, 2005.
Summary
• Older adults have decreased reserves in
multiple organ systems.
• Disease burden and functional capacity
outweigh age when assessing preoperative
risk.
• Collaboration among providers helps to
identify functional, cognitive and nutritional
deficits and to create management plans to
minimize these deficits when possible.