1.25 Myotonic Dystrophy

Question 1

PreOperative assessment

Hx

Answer 1

Standard preop assessment special attention to

Symptoms of Cardioresp dysfxn
chest pain sob palpitations peripheral oedema

Exercise tolerance

Difficulties in swallowing
Clearing secreation
-indicate presence of bulbar palsy

Other Comorb
DM Thyorid adrenal

Question 2

Exam

Answer 2

Exam

Signs of cardiac failure

Mid systolic click murmur
MV prolapse
20% patients

Question 3

Invx

Answer 3

CVS
ECG +/- Echo (PRN)

Respiratory
CXR ABG PFTs (PRN)

U+E Glucose

Premed
?Antacid + prokinetic
risk aspiration
bulbar palsy 
emptying

Question 4

Anaesthetic techniques

Answer 4

1. Intubation
   aspiration
2. Intubation w/out NMB desirable
3. NDMB
   unpredictable effects
   short acting
   w/ spont reversal
4. Sux / Neostig / PNS
   - Precip Myotonic contractions
   - Avoided
5. Invasive HD monitoring
   Cardiac dysfxn evident

Question 5

Anaesthetic techniques

Answer 5

6. Induction agents / High volatiles
   may cause significant CVs instability
7. Maintain adequate core body temp
   - avoid shivering induced myotonia
8. Rx of myotonia
   direct injection of LA
   Phenytoin / Quinine
9. Consider RA tech
   Reduce postop opioid
10. Post opp management HDU/ ICU if signif Cardioresp