5. Elderly Flashcards
What are the anaesthetic considerations for the elderly
patient?
Elderly patients are
not a homogenous group and age,
per se, cannot be
used as a sole indicator of peri-operative risk.
It is possible for a 20-year-old to have more significant co-morbidities than a 90-year-old
and present with a higher peri-operative risk.
However, elderly patients are often complex due to
a combination of age-related physiological decline, co-morbidities, cognitive impairment, frailty and polypharmacy.
This is associated with an increased
risk of morbidity and mortality after elective and especially emergency surgery.
Therefore, good peri-operative care is essential in reducing this risk and improving outcome.
General principles:
General principles:
> Multidisciplinary care improves outcome
for elderly surgical patients and
the anaesthetist is an integral part of the multidisciplinary team (MDT).
> Decision to operate should be made
at consultant level in conjunction
with the patient, family and MDT.
> Appropriately experienced senior personnel
should be available to anaesthetise
and operate on the patient.
> Suitable level of post-operative care should be arranged (e.g. HDU or ITU).
Pre-operative assessment:
Pre-operative assessment:
> A detailed medical and anaesthetic history
is important,
but this can sometimes be difficult due to deafness, aphasia and cognitive impairment or dementia.
> Some patients are poor historians and may not be aware of their medical issues or medication.
> A collaborative history from family members or carers can be useful.
History:
> Background to admission –
e.g. if patient had a fall and sustained a
fractured neck of femur,
it is essential to identify whether the fall was
mechanical or secondary to another cause,
like syncope.
> Co-morbidities should be identified
along with their severity.
> Pacemakers (PPMs) and implantable defibrillators (ICDs) need to be identified –
ICDs need to be turned off prior to surgery
and PPMs should have been checked within
the last 6 months – liaise early with pacemaker
clinic.
Consideration needs to be made on the choice of intra-operative diathermy
> Gastro-oesophageal reflux disease (GORD)
is more common – this can
increase the risk of aspiration.
> Joint replacements are more common –
this affects placement of the
diathermy pad and can affect
patient positioning for surgery.
> Drug history and allergies –
polypharmacy is common and there is
increased risk of drug interactions.
> Functional capacity –
premorbid level of exercise tolerance
(e.g. ability to walk on flat for a specified distance,
ability to climb a flight of stairs without stopping,
ability to perform activities of daily living independently)
provides an indication of cardiopulmonary reserve.
It is important to identify where necessary
what the limiting factor to exercise tolerance
is
(e.g. arthritic hip pain, calf claudication pain, chest pain, shortness of breath, balance, fragility).
> Social circumstances – knowledge of this (e.g. nursing home, social care package)
helps discharge planning.
> Drug chart and medical note review.
> Nutritional assessment – all elderly patients should have a nutritional assessment on admission.
Good nutrition facilitates healing and recovery.
If malnutrition is identified, oral nutritional supplements (e.g. iron, vitamin B12, folate)
should be commenced. In some cases, nasogastric feeding may be required.
Examination:
> Mini Mental State score –
this is useful to identify early onset dementia
and memory impairment.
It provides a benchmark that
can be referred to in the post-operative period.
> Targeted examination should be performed –
previously unrecognised pathology may be identified (e.g. ejection systolic murmur of aortic stenosis).
> Observation chart review –
baseline blood pressure should be noted, as
patients are prone to intra-operative hypotension.
Investigations:
> ECG, FBC, U&Es, blood sugar –
minimum data set required.
> Targeted investigations as required –
e.g. cardiac ECHO if murmur or
heart failure suspected,
CXR if lower respiratory tract infection
or heart failure is suspected.
Intra-operative considerations:
The choice of anaesthesia;
regional or general has not been shown to have
any significant difference in patient outcome.
What is more important is that
the technique used must be administered responsively taking into account
the patient’s physiological status.
Level of monitoring:
• Low threshold for invasive
blood pressure monitoring
in cases where
large blood loss or fluid shifts are expected and/or an underlying cardiovascular disease is suspected.
• Depth of anaesthesia monitoring (e.g. BIS or entropy) – this is useful as the dose of anaesthetic agents required to induce and maintain anaesthesia decreases with increasing age, but the deleterious
cardiovascular effects of these agents increase.
Monitoring depth of anaesthesia helps titrate dose to effect, minimising hypotension and overdose.
> Drugs:
• Increased sensitivity to induction agents,
inhalational agents,
benzodiazepines and opioids –
increased risk of hypotension
and effects of these drugs are more prolonged – reduced doses should be used.
• Arm–brain circulation is increased –
intravenous induction agents
should be administered slowly
and at a reduced dose.
• Autonomic responses are blunted – patients are more prone to hypotension.
Airway:
• Pre-oxygenate all patients as age
causes a gradual increase in closing capacity, increasing risk of desaturation.
• Edentulous patients are more difficult
to face-mask ventilate.
• Neck stiffness,
cervical spondylosis or
arthritis may limit neck
extension, making airway maintenance and intubation more difficult.
• GORD increases risk of aspiration.
Other
> Patient positioning –
meticulous care to protect pressure points with
adequate padding is essential as risk of neuropraxia and pressure sores is increased.
> Warming – patients are prone to hypothermia so fluid warmers and body warmers should be routinely used and intra-operative temperature monitoring be undertaken.
> Maintenance – MAC is reduced in elderly. Short-acting agents (e.g. desflurane and sevoflurane) are preferred.
> Fluid management –
fluid and electrolyte therapy can be challenging in elderly patients due to reduced homeostatic compensation for blood and/or fluid loss (in addition, patients may be taking diuretics).
Hydration status should be based on pre-operative hydration, intra-operative losses, urine output, blood pressure and cardiac output monitoring parameters when applicable.
Patients are prone to both dehydration
(if nil by mouth times have been excessive)
and fluid overload especially
if cardiac failure or renal failure is present.
Aim to maintain euvolaemia.
Post-operative considerations:
> Analgesia:
Post-operative considerations:
> Analgesia:
• Inadequate analgesia for elderly surgical patients contributes to post-operative morbidity including delirium, cardiorespiratory complications (pain increases sympathetic drive, which increases
myocardial oxygen consumption) and failure to mobilise.
• Pain should be assessed regularly and pain levels and sedation scores documented.
• Assessment can be difficult due to cognitive impairment, dementia and aphasia, and therefore non-verbal cues (e.g. facial expression,
posture, grimacing) should also be used.
• The use of peri-operative analgesia protocols improves patient satisfaction but should be individualised for each patient (e.g. previous
chronic pain status, renal function).
• A multimodal approach to analgesia is best (e.g. local anaesthetic infiltration by surgeons, wound catheters, regional anaesthetic techniques and WHO analgesic ladder).
• NSAIDs should be used with caution at the lowest dose and for the shortest duration due to the risk of gastric bleeding and nephrotoxicity.
Proton pump inhibitors should be prescribed and
U&Es be monitored.
- Morphine and other opiates are effective but should be administered cautiously and dose adjusted, especially in patients with renal impairment, respiratory compromise or cognitive impairment.
- Acute pain team should be involved.
> Post-operative delerium:
• Some decline in post-operative cognitive
function is common in
elderly patients.
Delirium in the recovery room is a
strong predictor for post-operative delerium.
- Features include acute confusion, disorientation, restlessness, agitation, fear, disturbed sleep, and hallucinations with symptoms often being worse at night.
- Causes include drugs
(e.g. atropine, benzodiazepines, opioids, antihistamines, sedative hypnotics and corticosteroids),
infection (e.g. UTI),
metabolic (e.g. hypo/hypernatraemia),
hypoperfusion (e.g. blood
loss or low cardiac output state),
hypoxia/hypercarbia and pain.
• High-quality peri-operative care reduces the incidence of delirium.
> Post-operative cognitive dysfunction (POCD):
• Resembles dementia and
can present weeks or months after surgery.
- Features include change in mood and behaviour, impairment in memory, learning, language and motor function.
- Diagnosis requires formal neuropsychological testing.
- Up to 25% of elderly patients can be affected at 1 week post-operatively and 10% at 3 months.
- Treatment involves good analgesia and correction of physiological parameters, and involvement of psychogeriatricians.
> Re-enablement:
Early mobilisation, rehabilitation, physiotherapy and occupational therapy facilitate good post-operative outcome.
‘Re-enablement’ is the process
of getting a patient to return to their pre-operative functional level and involves an MDT approach at each stage of the patient’s journey; from their admission, operation, post-operative care and rehabilitation. In order to have a good outcome,
the patient must receive a high standard of care
at each phase of their care pathway. The anaesthetist plays a vital role in risk stratification, ensuring age-appropriate anaesthesia, fluid therapy,
thermoregulation, analgesia, communication and arranging the appropriate
level of post-operative care.
