Parkinson’s disease

 

Disease:

Pathophysiology

·           Degenerative of dopaminergic neurons in substantia nigra

·           Cause: idiopathic, drugs, basal ganglia infarct

·           Not symptomatic until late in disease (60-80% of neurons gone)

·           Patients become progressively medication-resistant

Features

Motor:

·           Early: bradykinesia + rigidity + asymmetric resting ‘pill-rolling’ tremor

·           Late: shuffling gait, freezing, expressionless face, dysphagia

·           Risk of falls

Non-motor:

·           Early: fatigue, depression, insomnia, constipation

·           Late: dementia, autonomic dysfunction

If withdrawal from meds:

·           Motor: rigidity, ‘freezing’, rigidity of resp muscles, inability to clear secretions

·           Non-motor: anxiety, depression

·           NMS-like syndrome: agitation, delirium, death

Associated

·           Parkinson’s disease related dementia

·           Lewy body dementia

·           Parkinson’s plus syndromes (e.g. multiple system atrophy)

Treatment

Drugs: (note increasingly frequent doses required)

·           L-DOPA (dopamine precursor)

·           Carbidopa (peripheral DOPA decarboxylase inhibitor)

·           Dopamine agonist (bromocriptine, apomorphine, pramipexole, rotigotine)

·           MAO-B inhibitor (selegiline)

·           COMT inhibitor (entacapone)

Surgery:

·           Deep brain stimulator

·           Other e.g. thalamotomy, pallidotomy

 

Issues:

Medications

·           Don’t miss doses while fasting

o    If awake: oral (usual)

o    If anaesthetized: NG (usual)

o    If can’t absorb: IV (L-DOPA, apomorphine, patch (rotigotine)

o    Ask neurologist for assistance

·           Do not give anti-dopaminergics

o    Anti-emetics: metoclopramide, droperidol

o    Beware all psychoactive meds

·           Beware drug interactions:

o    Indirect SNS (if MAO inhibitor)

o    Serotonergics (if MAO inhibitor)

Airway

·           Rigidity -> risk of difficult intubation

·           Bulbar palsy + oesophageal dysfunction + gastroparesis -> risk of aspiration

·           Sialorrhoea -> avoid neostigmine

Breathing

·           Chest wall rigidity -> worse with opioids, risk of T2RF

·           Ensure complete reversal

·           Avoid excessive opioid; prefer non-opioid, neuraxial/regional

Circulation

·           Autonomic dysfunction common (esp multi-system atrophy)

Disability

·           Post-op delirium common (esp associated dementia)

 

 

Past SAQ

 

2015-1-10 A 68-year-old male with severe Parkinson's disease presents for elective right hemicolectomy. Current medications include selegiline (a monoamine oxidase inhibitor) and levodopa/benserazide. a. What clinical features of Parkinson's disease affect anaesthesia? (50%) b. Justify your perioperative drug management plan. (50%)

 

Examiner’s reports:

A. The significance of airway issues and one other significant clinical feature and show appropriate understanding that this patient has severe disease affecting anaesthetic management.

B. Avoidance of antidopaminergic drugs (i.e. needs to mention dopamine) and describe a reasonable plan to administer routine medication pre-operatively, justifying their thinking. Should also mention significance of MAOI's (particularly with opioids

 

a)Clinical features affecting anaesthesia:

·         Motor symptoms: bradykinesia, rigidity, asymmetric tremor

·         Non-motor features: anxiety, depression, cognitive impairment

·         Autonomic features: postural hypotension, urinary retention

·         Airway: sialorrhoea + impaired sputum clearance = risk of aspiration.

·         Breathing: resp muscle rigidity -> restrictive deficit, risk of T2RF

·         Circulation: risk of drug-induced hypotension

·         Disability (CNS): risk of delirium after GA

·         Medications: condition worsens if doses missed. Risk of drug interactions.

·         Deep brain stimulator: inappropriate use of diathermy is fatal

 

b)Management:

·         Pre-op

o   Fasting: as per usual guidelines

o   Medications: keep taking during fasting period.

·         Intra-op

o   Airway plan: coETT (since laparoscopy/laparotomy). Consider RSI due to autonomic neuropathy -> gastric stasis.

o   Induction drugs:

§  Fentanyl 3mcg/kg

§  Propofol 1.5mg/kg

§  Rocuronium 1mg/kg

o   Maintenance drugs:

§  Sevoflurane 0.8 MAC
Use BIS to prevent excessive narcosis, aim 40-60

o   Analgesia

§  Bilateral TAP catheters: inserted by surgeons if midline incision. Load ropivacaine 0.2% 10mL each side. Infusion 6mL/h each side. Remove day 3-5. (for opioid sparing)

§  Consider ketamine infusion 0.1mg/kg/h until extubation

§  Consider lignocaine infusion 1mL/kg then 1.5mL/kg/h until extubation

§  Fentanyl 0.5mcg/kg boluses PRN (prefer avoid resp depression)

o   Anti-emetics:

§  Dexamethasone 0.15mg/kg

§  Ondansetron 4mg

§  Do not give anti-DA drugs

o   Other drugs:

§  Parkinson’s drugs: consider crushing and giving via NGT if prolonged anaesthesia. Will need this for successful extubation.

§  Sugammadex for reversal, not neostigmine

§  Consider glycopyrrolate as antisialogogue

§  No ephedrine (risk of hypertensive crisis with MAOi)

§  No tramadol (risk of serotonin syndrome with MAOi)

·         Post-op

o   Analgesic: bilateral TAP catheters, paracetamol, fentanyl PCA if physically able to use; PRN oxycodone if not 5mg q3h.

o   Anti-emetic: 5HT3 antagonist preferred; DA antagonists contraindicated

o   Parkinson’s meds: ensure taken when due; if ileus then consider IV treatments (i.e. levodopa, apomorphine infusions)

 

 

 

2009-1-5 A 70 year old man with a 10 year history of Parkinson’s disease presents for a total knee replacement. He is levodopa/carbidopa five times a day. Outline the main issues to consider in relation to his Parkinson’s disease in planning their preoperative management of this patient?

 

Examiner’s reports:

 

Issues:

·         Motor symptoms: bradykinesia, rigidity, asymmetric tremor

·         Non-motor features: anxiety, depression, cognitive impairment

·         Autonomic features: postural hypotension, urinary retention

·         Airway: sialorrhoea + impaired sputum clearance = aspiration risk

·         Breathing: resp muscle rigidity -> risk type 2 resp failure

·         Circulation: risk of drug-induced hypotension

·         Disability (CNS): risk of delirium after GA

·         Medications: condition worsens if doses missed. Frequent doses here 5x per day.

·         Deep brain stimulator: inappropriate use of diathermy is fatal

 

·         Pre-op:

o   Fasting: as per usual guidelines

o   Medications: keep taking, right up until surgery. If not, symptoms will worsen.

o   Assessment: ensure optimized from neurology perspective

o   Investigations: resp function test if severe disease. May not change management.

o   Discussion: strongly recommend spinal > GA. Include NOK if appropriate.

·         Intra-op:

o   Monitoring:

§  Arterial line if autonomic dysfunction (e.g. multi-system atrophy)

§  Standard ANZCA monitoring

§  Sats probe on ear if tremor causing artifact

§  Capnography via Hudson mask

§  Consider IV phenylephrine infusion to minimize BP drop

o   Spinal anaesthetic immediately prior to surgery

§  0.5% bupivacaine 3.5mL

§  Fentanyl 20mcg

o   Sedation during surgery:

§  If able: best without sedation e.g. noise cancelling headphones

§  If very anxious: prefer propofol e.g. TCI 1-2mcg/mL

o   Surgery itself:

If DBS:

§  Bipolar diathermy where possible

§  Monopolar diathermy with plate on other thigh

§  Recommend urethral catheter

o   Adductor canal catheter immediately after surgery

§  Load with 10mL 0.2% ropivacaine; infusion 6mL/h

§  To be removed day 2 post-op

§  Reduces opioid requirement

·         Post-op:

o   Analgesic: paracetamol, fentanyl PCA if able to use; PRN oxycodone 5mg q3h if not

o   Anti-emetics: 5HT3 antagonist, H1 antagonist, no DA antagonist

o   Parkinson’s meds: ensure taken when due

o   Daily review by acute pain service