Finals Mcq Muscle Disorders

Front 1

ANZCA July 2007 [6]

The most frequently reported clinical sign in malignant hyperpyrexia is

A. arrhythmia

B. cyanosis

C. sweating

D. tachycardia

E. rigidity

Back 1

ANSWER D

Front 2

AM01 [1986] [1987]

In the laboratory test for malignant hyperpyrexia, the following are used:

A. Suxamethonium

B. Caffeine

C. Halothane

D. Potassium

E. Dibucaine

Back 2

ANSWER B and C

Front 3

AM02

Which of the following are useful in the treatment of malignant hyperpyrexia?

A. 100% 02

B. Phenytoin

C. Sodium dantrolene

D. Dextrose

E. Sodium bicarbonate

Back 3

ANSWER C

Front 4

AM03b [Mar91]

Which drug is known to trigger malignant hyperthermia?

A. Droperidol

B. Pancuronium

C. Neostigmine

D. Opioids

E. None of the above

Back 4

ANSWER E

Known "triggering drugs" are:

* ALL depolarising muscle relaxants (eg suxamethonium, suxethonium, decamethonium)
* All potent volatile anaesthetic agents

Front 5

AM04C ANZCA Version [Jul06] Q45

A 7 year old 30 kg. boy was booked for repair of an inguinal hernia. He was noted to have
muscular looking arms and legs. Following midazolam premedication anaesthesia was induced with thiopentone intravenously and N2O/O2 by mask. Airway difficulties led to his being given 30 mg. of
suxamethonium. He showed vigorous fasiculation followed by generalised muscular rigidity. The rigidity persisted despite another 30 mg. of suxamethonium intravenously. The probable cause of this response to suxamethonium is


A. atypical pseudocholinesterase

B. Duchenne's muscular dystrophy

C. familial periodic paralysis

D. hyperkalaemia

E. myotonia congenita

Back 5

ANSWER E

Myotonia congenita is transmitted as an autosomal dominant trait and becomes manifest at birth or during early childhood. Skeletal muscle involvement is widespread, but there is not usually involvement of other organ systems. Muscle hypertrophy and myotonia are present. The disease does not progress nor does it result in a decreased life expectancy. Patients with myotonia congenita respond to phenytoin, mexiletine, or quinine therapy. The response to succinylcholine administration is abnormal.

Front 6

AM06 ANZCA version [2003-Apr] Q132

In patients with hypokalaemic periodic paralysis one should avoid

A. anxiolytic drugs

B. beta-adrenergic antagonists

C. intravenous dextrose

D. regional anaesthesia

E. suxamethonium

Back 6

ANSWER C

Mutation on chromosome 17
-autosomal dominant pattern with a penetrance that is about 90% in males, but around 50% in females.
-1/3 no family history (sporadic)

Pathophysiology
- disturbance in ATP-sensitive potassium channel in skeletal muscle. Seems to be excessive potassium transport into muscle, especially in response to insulin. Total body potassium is normal

Clinical features
- usually presents in adolescence
- attacks vary widely in frequency and duration
- may be precipitated by high CHO or sodium meals
- affects bulbar & and respiratory muscles rarely
- +/- cardiac arrhythmias during death
- examination between attacks is normal

Triggers of hypokalaemic periodic paralysis
-mental stress
-cold
-beta-agonists
-carbohydrate load
-sodium load

Managment
- acute attacks respond to potassium
-oral preferred
-IV should be given with 5% mannitol (avoid dextrose and normal saline)
-potassium not effective in prophylaxis.
-Best agent appears to be acetazolamide: may block flux of potassium into muscle.
-Effectiveness may be related to metabolic acidosis

Individuals with HypoPP should be considered as susceptible to malignant hyperthermia and managed with a nontriggering anesthetic technique

Front 7

AM07 ANZCA version [2001-Apr] Q106 (type K)

The peri-operative management of a patient prone to hypokalaemic periodic paralysis should include

1. a reduced carbohydrate intake in the pre-operative twenty four hours

2. ready availability of intravenous acetazolamide

3. avoidance of intravenous sodium loads

4. the use of moderate intra-operative hyperventilation

Back 7

ANSWER 1 and 3

Mutation on chromosome 17
-autosomal dominant pattern with a penetrance that is about 90% in males, but around 50% in females.
-1/3 no family history (sporadic)

Pathophysiology
- disturbance in ATP-sensitive potassium channel in skeletal muscle. Seems to be excessive potassium transport into muscle, especially in response to insulin. Total body potassium is normal

Clinical features
- usually presents in adolescence
- attacks vary widely in frequency and duration
- may be precipitated by high CHO or sodium meals
- affects bulbar & and respiratory muscles rarely
- +/- cardiac arrhythmias during death
- examination between attacks is normal

Triggers of hypokalaemic periodic paralysis
-mental stress
-cold
-beta-agonists
-carbohydrate load
-sodium load

Managment
- acute attacks respond to potassium
-oral preferred
-IV should be given with 5% mannitol (avoid dextrose and normal saline)
-potassium not effective in prophylaxis.
-Best agent appears to be acetazolamide: may block flux of potassium into muscle.
-Effectiveness may be related to metabolic acidosis

Individuals with HypoPP should be considered as susceptible to malignant hyperthermia and managed with a nontriggering anesthetic technique.

Front 8

AM07 Black Bank version [1985] [1986] [Aug94] [Mar95] [Aug95] [Apr96] [Jul00] (type A)

In hypokalaemic periodic paralysis:

A. Should have (or Avoid) a high carbohydrate meal beforehand

B. Have Acetazolamide available

C. Avoid overloading with sodium/salt and water

D. Use GA and slightly hyperventilate

E. Need close postop monitoring of respiration

F. Avoid high CHO meal in 24 hours preop

G. Maintain mild hyperventilation

H. Avoid a high carbohydrate diet

Back 8

ANSWER

A. FALSE

B. FALSE : prevention not treatment

C. TRUE

D. FALSE : respiratory acidosis is protective

E. TRUE

F. TRUE

G. FALSE

H. TRUE

Front 9

AM08 [1988]

Neuroleptic malignant hyperpyrexia:
1. Unlike anaesthetic MH, it has no genetic element

2. Can be treated with bromocriptine

3. Can be treated with dantrolene

4. Occurs very rarely

Back 9

ANSWER 2,3,4

Front 10

AM09 [1987] [Aug92] [Mar93] [Mar94] [Aug94] [Mar95] [Jul97] [Apr98]

Neuroleptic malignant syndrome has all the following:

A. Caused by droperidol

B. Can be treated with Dantrolene

C. Unlike MH, does not have a hereditary (genetic) element

D. Is associated with tachycardia & hypotension

E. Is associated with peripheral vasoconstriction & other autonomic features

F. Leucocytosis

G. Nondepolarising relaxants reverse rigidity

H. Sux is contraindicated

I. Hyperthermia may not be present

J. CK rise

Back 10

A. Caused by droperidol - true: "Alcoholic patients are at greater risk of developing NMS during treatment of delirium or its prevention by droperidol or tiapride." (BJA (2000) 85; 129-35)

B. Can be treated with dantrolene - true: "Complete resolution was achieved more quickly with bromocriptine (10 days) or dantrolene (9 days; 2–3 mg kg–1 day–1 i.v. without exceeding 10 mg kg–1 day–1) than with supportive therapy (15 days)." (BJA (2000) 85; 129-35)

C. Unlike MH, does not have a hereditary (genetic) element - true

D. Is associated with tachycardia & hypotension - false: "Diaphoresis, tachycardia and abnormally high arterial pressure are common signs of autonomic dysfunction." (BJA (2000) 85; 129-35)

E. Is associated with peripheral vasoconstriction & other autonomic features - probably true

F. Leucocytosis - true "Leucocytosis, ranging from a slight elevation to 30 000 mm–3, is the only frequent laboratory finding included in the minor signs of NMS." (BJA (2000) 85; 129-35)

G. Nondepolarising relaxants reverse rigidity - likely true

H. Sux is contraindicated - false: "One study25 found that none of the patients who had NMS and underwent ECT, nor their relatives who had also undergone ECT, had any malignant hyperthermia-like symptoms or other secondary effects despite repeated use of succinylcholine in all cases." (BJA (2000) 85; 129-35)

I. Hyperthermia may not be present - false

J. CK rise - true: "NMS and malignant hyperthermia have clinical features in common, including hyperthermia, rigidity, an elevated creatine kinase concentration and a mortality rate for both NMS and malignant hyperthermia of 10–30%" (BJA (2000) 85; 129-35)

Front 11

AM09b

Features & management of the malignant neuroleptic syndrome do NOT include:

A. Genetically determined response to dopamine antagonists

B. Treatment with dantrolene

C. Hyperthermia, tachycardia & peripheral vasoconstriction

D. Raised white cell count

E. Hyperthermia not often seen

Back 11

ANSWER E

A. Genetically determined response to dopamine antagonists - true: now appears to be a genetic link

B. Treatment with dantrolene - true

C. Hyperthermia, tachycardia & peripheral vasoconstriction - probably true

D. Raised white cell count - true

E. Hyperthermia not often seen - false

NMS
-rare idiosyncratic genetic disorder
-reaction to antipsychotics
-resembles malignant hyperthermia
-hyperthermia
-tachycardia
-extrapyramidal signs : rigidity and dystonia
-automonic dysfunction : labile BP,sweating, salivation, incontinence
-CK and WCC increased
-mortality 20%

Front 12

AM09c ANZCA version [2004-Aug] Q94, [Jul06] Q93, [Apr07]

In the Neuroleptic malignant syndrome

A. there is a familial incidence

B. non-depolarizing muscle relaxants decrease the muscle rigidity

C. creatinine kinase levels are elevated following an episode

D. there is an association with malignant hyperpyrexia

E. hyperthermia does not always occur

Back 12

ANSWER A and B

A. there is a familial incidence - true:
o "Familial clusters of NMS suggest a genetic predisposition to the disorder. Genetic studies have shown that the presence of a specific allele of the dopamine D2 receptor gene is over represented in NMS patients. This allele is associated with reduced density and function of dopamine receptors as well as decreased dopaminergic activity and metabolism

B. non-depolarizing muscle relaxants decrease the muscle rigidity - true:
o "Many of the previous reports documented that succinylcholine may be safely used during ECT in a patient of NMS3, but some do not agree8, as even small dose of succinylcholine can produce side effects. Reports quote that mivacurium (0.15-0.25mg kg-1) and rapacuronium (0.6- 0.8 mg kg-1) may be safe alternatives to succinylcholine

C. creatinine kinase levels are elevated following an episode - false:
NMS and malignant hyperthermia have clinical features in common, including hyperthermia, rigidity, an elevated creatine kinase concentration and a mortality rate for both NMS and malignant hyperthermia of 10–30%" Note that it is CREATINE KINASE not CREATININE KINASE

D. there is an association with malignant hyperpyrexia - false
the association between NMS and other potentially fatal syndromes, such as malignant hyperthermia, is unclear

E. hyperthermia does not always occur - false:
Three major symptoms indicate a high probability of the presence of NMS: hyperthermia, rigidity and an elevated creatine phosphokinase concentration, reflecting rhabdomyolysis. In the absence of these criteria, the diagnosis of NMS should be questioned, since other symptoms of the disorder may be seen in patients taking neuroleptics without having NMS. Elevated temperature (38.5°C) in the absence of other systemic illness is observed in most patients

Front 13

AM09d ANZCA version [2005-Apr] Q92

Which of the following statements is NOT true of the neuroleptic malignant syndrome?

A. it is a rare complication of dopaminergic antagonist drugs

B. it may be successfully treated with bromocriptine

C. it may be successfully treated with dantrolene

D. unlike malignant hyperpyrexia it does not have a genetic component

E. the syndrome includes extra-pyramidal signs, hyperthermia peripheral vasoconstriction, tachycardia, dyspnoea and other autonomic manifestations

Back 13

ANSWER D

A. it is a rare complication of dopaminergic antagonist drugs - true: dopamine receptor blockade is central to most theories of its pathogenesis

B. it may be successfully treated with bromocriptine - true

C. it may be successfully treated with dantrolene - true

D. unlike malignant hyperpyrexia it does not have a genetic component - false:
o "Familial clusters of NMS suggest a genetic predisposition to the disorder. Genetic studies have shown that the presence of a specific allele of the dopamine D2 receptor gene is over represented in NMS patients. This allele is associated with reduced density and function of dopamine receptors as well as decreased dopaminergic activity and metabolism." (Uptodate)


E. the syndrome includes extra-pyramidal signs, hyperthermia peripheral vasoconstriction, tachycardia, dyspnoea and other autonomic manifestations - true

Front 14

AM09e ANZCA version [Apr08] Q79

The diagnosis of neuroleptic malignant syndrome requires the presence of:

A. Diaphoresis

B. elevated plasma creatinine kinase

C. hypertension

D. muscle rigidity

E. tachycardia

Back 14

ANSWER D

In the DSM-IV, there are criteria for diagnosis as follows (from Crit Care Med 2010 Vol. 38, No. 6 (Suppl) S244-52 (http://ovidsp.tx.ovid.com.ezproxy.anzca.edu.au/sp-3.2.4a/ovidweb.cgi?WebLinkFrameset=1&S=KPGAFPFAAJDDDOJKNCCLNBDCBBAJAA00&returnUrl=http://ovidsp.tx.ovid.com/sp-3.2.4a/ovidweb.cgi%3f%26Titles%3dS.sh.44%257c1%257c100%26FORMAT%3dtitle%26FIELDS%3dTITLES%26S%3dKPGAFPFAAJDDDOJKNCCLNBDCBBAJAA00&directlink=http://graphics.tx.ovid.com/ovftpdfs/FPDDNCDCNBJKAJ00/fs046/ovft/live/gv025/00003246/00003246-201006001-00017.pdf&filename=Adverse+drug+reactions+resulting+in+hyperthermia+in+the+intensive+care+unit.&navigation_links=NavLinks.S.sh.44.1&link_from=S.sh.44|1&pdf_key=B&pdf_index=S.sh.44))

A - Development of severe muscle rigidity and elevated temperature associated with the use of neuroleptic medication

B - Two or more of; Diaphoresis, dysphagia, tremor, incontinence, changes in level of consciousness ranging from confusion to coma, mutism, tachycardia, elevated or labile blood pressure, leukocytosis, laboratory evidence of muscle injury (ie, elevated creatine phosphokinase)

C - The symptoms in criteria A and B are not due to another substance (eg, phencyclidine) or a neurologic or other general medical condition (eg, viral encephalitis)

D - The symptoms in criteria A and B are not better accounted for by a mental disorder (eg mood disorder with catatonic features)

Front 15

AM10

Which of the following would you NOT expect to find in a patient with malignant hyperpyrexia?

A. Alkalosis

B. Increased serum potassium

C. Muscular rigidity

D. Increased temperature

Back 15

ANSWER A

Front 16

AM12 [Mar91] [Aug94]
Dystrophia myotonica:

A. The myotonia is abolished by regional (?spinal/epidural) anaesthesia

B. The severity of the cardiomyopathy parallels that of the skeletal muscle

C. Suxamethonium induces myotonia in all clinical cases

D. Pulmonary aspiration is common

E. Serum creatine phosphokinase is elevated

Back 16

A: False
* General anaesthesia, regional anaesthesia and neuromuscular blockers are not able to prevent or relieve this skeletal muscle

* AKA Myotonia Dystrophica. A form of myotonic dystrophy. Not to be confused with muscular dystrophy.
* Most common muscular dystrophy among Caucasians
* AD with variable penetrance
* Chromosome 19 locus q 12.3
* Defect is in Na conductance (via serine/threonin protein kinase) resulting in increased intra-cellular Na
* incidence of 1 in 8,000.
* A multisystem disorder,
* onset 10 – 30 yrs (a congenital form exists)
* distal muscles more involved than proximal muscles
* Plasma CK normal or sl elevated. (M&M, Harrisons)
* Progression:
o myotonia early (persistent contraction after voluntary or mechanical stimulation) then
o atrophy of face and neck, also
o frontal balding and cataracts,
o usually low intelligence,
o Also possible dysarthria, dysphagia, and mild ophthalmoplegia.

antagonist m. spasms when relaxes

Drug effects

* Prolonged respiratory depression with any resp depressant drug
* Treatment: Na channel blockers: quinine, phenytoin and procainamide

System effects

* CVS :
o conduction blocks (ECG : increased PR, ST and A flutter
o Cardiomyopathy (<10%)-note that severe skeletal muscle disease is not necessary for a sever cardiomyopathy (see AIC 2001: Anaesthesia and myotonia-an Australian experience.)
* Resp :
o reduced VC,
o exp. Effort/Pressure;
o aspiration risk (common)
* GIT :
o Smooth mm is involved leading to dysmotility in stomach/oesophagus, colon, uterus
* Endocrine :
o Insulin resistance,
o adrenal atrophy,
o infertility in women,
o testicular atrophy, primary testicular abnormalities
* Early cataracts

Diagnosis

* Clincial
* +ve FHx
* EMG/Muscle bx
* Genetic testing for mild cases useful

Congenital form occurs in children born to mothers with myotonic dystrophy; some patients present with profound hypotonia at birth, with facial diplegia, feeding, respiratory difficulties, and skeletal deformities (such as clubfeet). Later, during childhood, delayed developmental progression is noted contraction...Stoelting

B: False
* Cardiac abnormalities have been well described in patients with myotonic dystrophy. The most prominent cardiac disorders include atrioventricualr conduction delays (A-V block), atrial flutter and fibrillation, and ventricular dysrhythmias. First-degree A-V block may actually precede the onset of skeletal muscle symptoms. Sudden death may be a result of the abrupt onset of third-degree A-V block. Other cardiac abnormalities associated with myotonic dystrophy include mitral valve prolapse, left ventricular diastolic dysfunction, and cardiac failure...Barash, Clinical Anaesthesia

C: True (?)
* Succinylcholine produces an exaggerated contracture and its use should be avoided. The myotonic response to succinylcholine can be so severe that ventilation and tracheal intubation are difficult or impossible...Barash, Clinical Anaesthesia
* Succinylcholine will produce contractions lasting for several minutes, thus making intubation and ventilation a challenge...Miller

D: True
* Pharyngeal muscle weakness in conjunction with delayed gastric emptying increases the risk of aspiration of gastric contents...Barash, Clinical Anaesthesia

E: True
* MD patients may also have mildly elevated CK levels...Miller

Front 17

Dystrophia myotonica

Back 17

* AKA Myotonia Dystrophica. A form of myotonic dystrophy. Not to be confused with muscular dystrophy.
* Most common muscular dystrophy among Caucasians
* AD with variable penetrance
* Chromosome 19 locus q 12.3
* Defect is in Na conductance (via serine/threonin protein kinase) resulting in increased intra-cellular Na
* incidence of 1 in 8,000.
* A multisystem disorder,
* onset 10 – 30 yrs (a congenital form exists)
* distal muscles more involved than proximal muscles
* Plasma CK normal or sl elevated. (M&M, Harrisons)
* Progression:
o myotonia early (persistent contraction after voluntary or mechanical stimulation) then
o atrophy of face and neck, also
o frontal balding and cataracts,
o usually low intelligence,
o Also possible dysarthria, dysphagia, and mild ophthalmoplegia.

antagonist m. spasms when relaxes

Drug effects

* Prolonged respiratory depression with any resp depressant drug
* Treatment: Na channel blockers: quinine, phenytoin and procainamide

System effects

* CVS :
o conduction blocks (ECG : increased PR, ST and A flutter
o Cardiomyopathy (<10%)-note that severe skeletal muscle disease is not necessary for a sever cardiomyopathy (see AIC 2001: Anaesthesia and myotonia-an Australian experience.)
* Resp :
o reduced VC,
o exp. Effort/Pressure;
o aspiration risk (common)
* GIT :
o Smooth mm is involved leading to dysmotility in stomach/oesophagus, colon, uterus
* Endocrine :
o Insulin resistance,
o adrenal atrophy,
o infertility in women,
o testicular atrophy, primary testicular abnormalities
* Early cataracts

Diagnosis

* Clincial
* +ve FHx
* EMG/Muscle bx
* Genetic testing for mild cases useful

Congenital form occurs in children born to mothers with myotonic dystrophy; some patients present with profound hypotonia at birth, with facial diplegia, feeding, respiratory difficulties, and skeletal deformities (such as clubfeet). Later, during childhood, delayed developmental progression is noted

Front 18

AM14

Dantrolene sodium:

A. Has muscle relaxant properties

B. Has muscle stimulant properties

C. Is used in the treatment of malignant hyperpyrexia

D. Is more soluble in acidic solution

E. Decreases intracellular Ca++

Back 18

ANSWER A C E

Front 19

AM15a [Mar90]

Myasthenia gravis: which is NOT true?

A. Increased incidence in males compared to females

B. Increased response to muscle relaxants

C. Aggravated by pregnancy

D. .....?...IgM......?

E. Neonates may be born with muscle weakness

Back 19

ANSWER A

A = false, more common in females cf myasthenic syndrome(pg 527 Stoelting and Dierdorf)

B = true (pg 527 Stoelting and Dierdorf)

C = true (muscle weakness may be precipitated or aggravated by; infections, electrolyte abnormalities, pregnancy, emotional stress and surgery)(pg 524 S&D)

D ?

E = true

Front 20

AM15b [Mar91] [Mar93] [Aug93]

Myasthenia gravis:

A. Is associated with antibodies affecting acetylcholine release

B. Best treated with thymectomy and/or steroids in the young

C. Becomes self-limiting in old age

D. Affects the babies of mothers with the disease

E. Is not an antibody mediated disease

Back 20

ANSWER D

A = false - is referring to myasthenic syndrome

B = ?false - see page 524 S&D, ?anticholinesterase drugs are prob still FIRST line treatment.

C = presumably false - given duration of disease is a predictive for requiring post op ventilatory support. "clinical course is marked by exacerbations and remissions" - pg 524 S&D

D = true - see above

E = false

Front 21

AM16 [Mar90] [Mar91] [Mar92] [Apr98] [Mar06] Aug10

Recognised clinical associations with Dystrophia myotonia include:

A. development of diabetes mellitus

B. abnormal intestinal motility

C. cardiomyopathy

D. ovarian dysfunction

E. all of the above

Back 21

ANSWER E

A- Insulin Resistance

B- May affect intestinal smooth muscle

C- Does not necessarily correlate with severity of skeletal muscle involvement

D- Females may be amenhorreic or have problems with infertility. Men have testicular atrophy.

E- Hence all of above are true.

Front 22

AM17a [Sep90]

Dystrophia myotonia associated with:-

A. High arched palate

B. Risk of aspiration

C. Thyroid disease

D. Optic atrophy

E. None of the above

Back 22

ANSWER B

Front 23

AM17d ANZCA version [2005-Apr] Q26

Myotonic dystrophy

A. usually presents before puberty

B. is frequently associated with cardiac failure

C. is associated with obstructive lung disease

D. contractions are not relieved by nondepolarising neuromuscular blockers and deep anaesthesia

E. is associated with mitral valve in over 50% of patients

Back 23

ANSWER D

Myotonic dystrophy: Cataracts, subcapsular deposits, diabetes, cardiac conduction defect (30-40%), diastolic cardiac dysfunction (can occur) but cardiac failure is rare, no mention of valve disease, increased sensitivity to anaesthetic drugs, mental retardation may occur, frontal balding, testicular atrophy, ovarian dysfunction, respiratory limitation is restrictive, central and obstructive sleep apnoea, decreased smooth muscle motility à bowel and uterus (atony). Usually presents in young adulthood.

Front 24

AM19 [Mar91] [Aug91] [Mar92] [Aug93] [Aug95]

Duchenne muscular dystrophy:

A. May cause myoglobinuria (? or myoglobinaemia) post-suxamethonium

B. Associated with sudden death postoperatively

C. Commonly associated with cardiomyopathy

D. Can be present in a seemingly muscular person

E. Inheritance is autosomal dominant

Back 24

ANSWER A B C D

DMD:

* Incidence: 3 per 100 000 births
* Inheritance: X-linked recessive, therefore DMD primarily affects males
* Skeletal muscles: Most individuals are wheelchair bound by 8–11 years of age.
* Respiratory: Respiratory muscle weakness leading to pulmonary insufficiency is a leading cause of morbidity and mortality in DMD. Respiratory failure inevitably occurs in the second decade of life
* Cardiac: DMD-associated cardiomyopathy begins at the same time as clinically evident skeletal muscle dysfunction. By 15 years of age, over 50% of patients have some degree of dilated cardiomyopathy with a reduced ejection fraction (<45%). Even patients with apparently normal preoperative cardiac workup may succumb to adverse perioperative cardiac events.

Front 25

AM21 ANZCA version [2003-Aug] Q49, [2004-Aug] Q38, [2005-Apr] Q29 (Similar question reported in [Mar94] [Aug94] [Mar95] [Aug95] [Apr96] [Aug96] [Jul97] [Apr98] [Jul98])

The preferred technique of anaesthesia for reduction of a fractured wrist in a patient with myotonic disorder

A. general anaesthesia with spontaneous ventilation using a volatile agent

B. general anaesthesia with suxamethonium-induced muscle relaxation

C. general anaesthesia with a non-depolarising relaxant reversed by neostigmine

D. intravenous regional anaesthesia with lignocaine

E. axillary brachial plexus block with lignocaine

Back 25

ANSWER E

1. Perform an extensive preoperative evaluation. Organize a multi-disciplinary medical team.
2. Use regional anesthesia when appropriate.
3. Be cautious with premedications (benzodiazepines and opioids).
4. Keep the patient warm.
5. Consider applying defibrillator/pacer pads.
6. On induction, be aware of the high likelihood of aspiration and other airway complications. Avoid succinylcholine when possible.
7. Adhere to strict extubation criteria. Given the effects DM has on the pulmonary system, anticipate the need for supportive mechanical ventilation until extubation criteria are met.
8. Plan for the continuous SpO2 and EKG monitoring postoperatively.
9. Manage postoperative pain with NSAIDs, regional techniques, and acetaminophen when appropriate. Use opioids with extreme caution.
10. Encourage aggressive pulmonary toileting postoperatively.

Front 26

AM22 [Aug95] [Jul98] [Apr99] [Aug99] (type A)

Patient with suspected malignant hyperpyrexia. Which of the following is/are true?

A. Chance of affected sibling is 25%

B. CK level is elevated at all times

C. Report of a case occurring 48hrs after anaesthesia

D. It is possible for the patient to have had a previous anaesthetic & not triggered a reaction

Back 26

ANSWER C and D

A ? False Close to 50% (OHA)Originally thought to be dominant but genetics not really understood. (Blue Book 2005)

B False Peak CK at 24hrs. (CEPD 2003)

CK levels have been considered as screening tool. "... some families in which people susceptible to MH have high CK levels." (Australian Anaesthesia 2005, p42)

C True may rarely present 2-3 days post op with ARF (OHA)

D True 50-75% of patients have had a prev anaesth without problems (OHA)

Two-thirds of MHS patients manifest during their first GA

One-third of MHS patients manifest during subsequent GAs

Front 27

AM23 [Apr96] [Jul98]

To relieve myotonia:

A. Inject procaine into muscle

B. Neostigmine

C. Isoflurane

D. Propofol

Back 27

ANSWER A

Surgical manipulation and diathermy may cause myotonic contractions

Relieved by:

* Phenytoin
* Procainamide gb-quinine and mexiletine
*direct injection with ESTER LA
* High concentration of volatile anaesthetic (at the expense of myocrdial depression)

Front 28

AM24 [Aug96]

Malignant hyperthermia:

A. Autosomal recessive inheritance

B. Defect located on chromosome 15

C. Calcium concentration increased in normal muscle cell

D. ?

Back 28

Inheritance of malignant hyperthermia is autosomal dominant
-variable penetration and expression
-numerous genetic mutations responsible for this disorder
-not all of them directly affect the ryanodine receptor
-chromosome 19.

Front 29

AM25a ANZCA version [2001-Aug] Q54, [2003-Apr] Q60, [2005-Sep] Q84, [Mar06] Q62 (Similar question reported in [Aug96])

In an acute malignant hyperthermia episode

A. the serum creatinine kinase level peaks within one hour

B. the peak serum creatinine kinase level is a good indicator of the amount of muscle involved

C. elevated creatinine kinase levels contribute to acute renal failure

D. the serum myoglobin level does NOT peak for at LEAST 24 hours

E. muscle rigidity occurs in 75% of cases

Back 29

A - FALSE
* creatine kinase peaks around 24 Hrs?

B - FALSE
* peak serum CK is not a reliable indicator of MH vs non-MH, as CK levels of MH patients often within levels expected from surgery itself..."patients who have had an acute MH episode during a surgical procedure may have peak CK values within the range of CK values expected from the procedure itself"...Creatine kinase alterations after acute malignant hyperthermia episodes and common surgical procedures
o Serum myoglobin (by radioimmunoassay) and creatine kinase were measured for up to 7 days in 30 patients following surgical procedures, including total hip replacement and bilateral subcostal abdominal incisions. Serum myoglobin reached a maximum of 1390 µg litre–1 (median 345 µg litre–1 for major surgery patients) on the first postoperative day but levels were still elevated by day 7 in some patients. Creatine kinase reached a maximum of 1339 i.u. litre–1 at day 2 (median 422 i.u. litre–1 for major surgery patients), generally peaking 1 day after myoglobin in individual patients. These values may have significance when investigating a suspicion of coincident perioperative events such as myocardial infarction or malignant hyperthermia...Serum myoglobin and creatine kinase following surgery

C - FALSE
* Myoglobin

D - FALSE
* myoglobin peaks ~ 6hrs later

E - TRUE

* rigidity 80%

Front 30

AM26 [Jul97] [Apr99] [Aug99]

Dystrophia myotonica (type A)

A. Thiopentone may cause prolonged respiratory depression

B. Non-depolarising relaxants are useful for blocking contractures

C. Volatiles & neuromuscular blockers do not block myotonia

Back 30

ANSWER A and C

Front 31

AM28a ANZCA version [2002-Mar] Q35, [2002-Aug] Q24 (Similar question reported in [Apr98] [Jul98] [Apr99] [Aug99])

In a patient with myasthenia gravis undergoing a laparotomy for large bowel obstruction, the need for post-operative ventilation is significantly increased by a

A. daily dose of pyridostigmine > 450mg

B. known history of resistance to suxamethonium

C. past history of prednisolone treatment > 10 mg.day-1

D. recent history of dysphagia

E. past history of thymectomy

Back 31

ANSWER D

Preoperative predictors of postoperative need for ventilation:

* duration of disease of greater than 6 years
* history of coexisting chronic resp disease
* dose requirements of pyridostigmine > 750 mg/day less than 48 H prior to surgery
* preoperative VC < 2.9L

Front 32

AM28b ANZCA version [2003-Apr] Q136, [2004-Aug] Q30, [2005-Apr] Q27

In a patient with myasthenia gravis undergoing a laparotomy for large bowel obstruction, the need for post-operative ventilation is significantly increased by a

A. daily dose of pyridostigmine > 180mg

B. known history of resistance to suxamethonium

C. known history of sensitivity to non-depolarising muscle relaxants

D. past history of prednisolone treatment > 10 mg.day-1

E. recent history of dysphagia

Back 32

ANSWER E

Preoperative predictors of postoperative need for ventilation:

* duration of disease of greater than 6 years
* history of coexisting chronic resp disease
* dose requirements of pyridostigmine > 750 mg/day less than 48 H prior to surgery
* preoperative VC < 2.9L

Front 33

AM28c [Mar06] [Jul06] [Apr07] Q136

In a patient with myasthenia gravis undergoing a laparotomy for large bowel obstruction, the need for post-operative ventilation is significantly increased by a

A. High daily doses of pyridostigmine

B. Long history of the disease

C. Previous exaggerated response to NMDBs

D. Previous crisis requiring ventilation

E. Bulbar palsy

Back 33

ANSWER C

Preoperative predictors of postoperative need for ventilation:

* duration of disease of greater than 6 years
* history of coexisting chronic resp disease
* dose requirements of pyridostigmine > 750 mg/day less than 48 H prior to surgery
* preoperative VC < 2.9L

Front 34

AM29 [Jul98] (type A)

A 16 year old male patient with peritonitis undergoing appendicectomy has suspected MH. (History of ?grandmother/aunt died under anaesthetic). What would suggest/prove MH? (Or: MH reliably diagnosed if:)

A. Elevated intraop temp > 39.5C

B. Masseter spasm

C. Intraop hypercapnia to >45mmHg

D. Postop elevated creatinine kinase

E. None of the above

Back 34

ANSWER E

A. Elevated intraop temp > 39.5C

* Intermediately timed sign of MH

B. Masseter spasm

* Early Sign of MH

C. Intraop hypercapnia to >45mmHg

* Early sign of MH

D. Postop elevated creatinine kinase

* Late sign of MH

E. None of the above

Front 35

AM30 ANZCA version [2003-Aug] Q92

Which of the following myopathies is associated with an increased risk of malignant hyperpyrexia?

A. central core disease

B. centronuclear myopathy

C. fingerprint body myopathy

D. multicore myopathy

E. nemaline myopathy

Back 35

ANSWER A

A whole series of articles appears in A&A October 2009 which states that the following diseases could be MHS

* Central Core Disease
* Multiminicore Diease and Nemaline rod disease both having forms associated with RYR1 Mutation are considered high risk, despite the lack of case reports. (Apparently no one had used volatiles in patients know to have MmD!)
* Brody Myopathy
* King-Denborough Syndrome
* Hypokalaemic Periodic Paralysis is possible
* Burkitt's Lymphoma
* Osteogenesis imperfecta
* Myotonia congenita
* NMS
* Myelomeningocele

Front 36

AM31 ANZCA version [2004-Apr] Q11 (Similar question reported in [Apr99] [Mar00])

Malignant hyperthermia:

A. May be confirmed by a muscle biopsy showing contracture in response to halothane, caffeine & calcium

B. Is an autosomal recessive disorder

C. Should be treated with an initial dose of dantrolene of 2.5mg/kg

D. Had a mortality as high as 50% prior to dantrolene

E. Is consistently associated with a rapidly rising temperature as one of the early signs

Back 36

ANSWER C

Front 37

AM32 [Apr99]

In comparing the serotonergic syndrome with the neuroleptic malignant syndrome:

A. Abnormal ocular signs with serotonin but not NMS

B. Muscular rigidity of the lower limbs different to that seen in NMS

C. Can be triggered by dopamine agents unlike NMS which can be triggered by dopamine antagonists like bromocriptine

D. More rapid onset & shorter duration with serotonin syndrome

Back 37

ANSWER B and D

A - False (?)
* Mydriasis with serotonin syndrome (? also ping-pong gaze)

B - True
* lead-pipe rigidity in NMS and hyperreflexia, tremors and clonus in SS.

C - False
* Bromocriptine is a dopamine agonist used in the treatment of NMS.
* Bromocriptine can cause SS

D True
* NMS has a slow onset (days to weeks) and a slow progression of 24-72 hours, whereas serotonin syndrome has a more rapid onset and progression.


SS and NMS can be difficult to distinguish
-mydriasis
-hyperreflexia
-tremors
-myoclonus
-diarrhoea

Front 38

AM33 ANZCA version [2001-Apr] Q130 (Similar question reported in [Mar00] [Jul00])

Neuroleptic Malignant Syndrome may be precipitated or exacerbated by

1. metoclopramide

2. droperidol

3. thioxanthenes

4. bromocriptine

Back 38

ANSWER 2

Neuroleptic malignant syndrome occurs in a small percentage of patients (<1%) taking potent dopamine ANTagonists (eg neuroleptics such as haloperidol

Also atypical antipsychotic agents, including clozapine (Clozaril), risperidone (Risperdal), olanzapine (Zyprexa), and quetiapine (Seroquel)

The earliest symptom is usually marked muscle rigidity due to excessive extra-pyramidal activity resulting from excess dopamine receptor antagonism.

The syndrome is characterized by the following features:
* Autonomic dysfunction
* Elevations in CK and white blood cell count
* Fever
* Hyperthermia
* Mental status changes
* Severe muscle rigidity
* Tremor.

The 3 major signs supporting the diagnosis of NMS are:
* Hyperthermia
* Muscle rigidity (usually lead-pipe rigidity)
* Elevated creatine phosphokinase (>1,000 IU) - indicating myonecrosis

Management
* Early recognition and cessation of neuroleptic drugs
* Exclusion of infection as a cause for fever (eg blood cultures, antibiotics)
* Supportive measures (eg use of physical cooling methods, cardiorespiratory support and monitoring, diuresis to avoid renal failure)
* Use of specific drugs may be useful, for example:
o dantrolene - a direct skeletal muscle relaxant
o bromocriptine - a dopamine agonist
o diazepam - central skeletal muscle relaxant and sedative.

Front 39

AM34 [Mar00] [Jul00]
Myotonia:

A. (?Not) Reversed with neuromuscular blockade

B. Autosomal dominant appearing 2nd-3rd decade

C. Not reversed with deep inhalational anaesthesia

D. Not reversed with regional anaesthesia

E. Give volatiles & NM blockers to help contractures

Back 39

ANSWER B and D

Front 40

AM35 ANZCA version [2001-Aug] Q101, [2002-Mar] Q106
Myotonia dystrophica

1. is associated with cataracts

2. is strongly associated with malignant hyperpyrexia

3. can result in increased sensitivity to respiratory depressants

4. has its inheritance best described as autosomal recessive

Back 40

ANSWER 1 and 2

Myotonic dystrophy is a dominantly inherited disease characterized by myotonia, progressive myopathy, insulin resistance, defects in cardiac conduction, neuropsychiatric impairment, cataracts, testicular atrophy, and frontal balding in males.[935] Patients with myotonic dystrophy have increased mortality from respiratory complications secondary to aspiration as a result of their muscle weakness, as well as cardiac dysrhythmias.

MH association just is not true. This may be referring to Myotonia Congenita which may be associated with susceptibility to MH

Front 41

AM36 ANZCA version [2001-Aug] Q134
Therapies that have been reported to be useful in the management of Neuroleptic Malignant Syndrome include
1. dantrolene

2. bromocriptine

3. levodopa

4. amantadine

Back 41

ANSWER ALL

Front 42

AM37 ANZCA version [2002-Mar] Q133
The caffeine-halothane contracture test for malignant hyperthermia

1. may be performed up to 24 hours following collection of the specimen

2. has a 10 - 20% false positive rate

3. is indicated in patients with neurolept malignant syndrome

4. requires that the muscle specimen has NOT been directly infiltrated with local anaesthetic

Back 42

ANSWER 2 4

1. False. The standard is 5 hours

2. True. Specificity (i.e. true negative rate) 78-94% (Miller 5th edn p 1049) or 85-90% therefore false positive rate 6-22% or 10-15%

3. False.

4. True. "The test must be performed on a biopsy of approximately 2 g of muscle from the vastus lateralis or medialis within 5 hours of harvesting. The patient is anaesthetized with general anaesthesia or with a femoral nerve block or one of its variants. In all cases the anaesthetic drugs used must be safe for MH-susceptible patients. Direct muscle infiltration with local anaesthetic is contraindicated because it could affect tissue viability.

Front 43

AM38 ANZCA version [2003-Aug] Q121, [2004-Apr] Q25, [Mar06]

The earliest sign in the development of malignant hyperthermia is

A. acidosis

B. hyperthermia

C. increased end-tidal carbon dioxide concentration

D. muscle rigidity

E. myoglobinuria

Back 43

ANSWER C

Diagnosis of MH (Table 2 from Ref)

1. Unexplained, unexpected increase in end-tidal carbon dioxide (most sensitive indicator of potential MH)
2. Unexplained, unexpected tachycardia and masseter muscle spasm usually follow the carbon dioxide increase
3. Mixed respiratory and metabolic acidosis
4. Skeletal muscle rigidity
5. Temperature elevation (often a late sign)
6. Laboratory abnormalities: blood—coagulation profile, electrolytes, arterial blood gas, creatine kinase; urine—myoglobin

Front 44

AM41 ANZCA version [2004-Aug] Q15, [Mar06] Q11, [Jul07]

The most frequently reported clinical
sign in malignant hyperpyrexia is

A. arrhythmia

B. cyanosis

C. sweating

D. tachycardia

E. rigidity

Back 44

ANSWER

Diagnosis of MH (Table 2 from Ref)

1. Unexplained, unexpected increase in end-tidal carbon dioxide (most sensitive indicator of potential MH)
2. Unexplained, unexpected tachycardia and masseter muscle spasm usually follow the carbon dioxide increase
3. Mixed respiratory and metabolic acidosis
4. Skeletal muscle rigidity
5. Temperature elevation (often a late sign)
6. Laboratory abnormalities: blood—coagulation profile, electrolytes, arterial blood gas, creatine kinase; urine—myoglobin

Front 45

AM39 ANZCA version [2003-Aug] Q98

Features of Guillain-Barre syndrome include:

A. distal loss of sensation

B. extensor plantar responses

C. facial weakness

D. proximal weakness greater than distal weakness

E. pseudobulbar palsy

Back 45

ANSWER A

Guillain-Barre syndrome (GBS) is a heterogeneous grouping of immune-mediated processes generally characterized by motor, sensory, and autonomic dysfunction.

In its classic form, GBS is an acute inflammatory demyelinating polyneuropathy characterized by progressive symmetric ascending muscle weakness, paralysis, and hyporeflexia with or without sensory or autonomic symptoms; however, variants involving the cranial nerves or pure motor involvement are not uncommon.

In severe cases, muscle weakness may lead to respiratory failure, and labile autonomic dysfunction may complicate the use of vasoactive and sedative drugs.

Treatment

The ONLY two effective treatments are:

* plasma exchange therapy
* intravenous immune serum globulin

Both treatment are very similar in efficacy, and can decrease recovery time by as much as 50%.

Corticosteroids are ineffective, and some case reports indicate they may slow recovery if used alone.

Outcome

80-85% of cases recover completely within 6-12 months.

Front 46

AM40 ANZCA version [2001-Apr] Q125

In testing for malignant hyperthermia susceptibility

1. an increase in contracture to either halothane or caffeine (during in vitro testing) is considered a positive result.

2. defects in the RYR1 gene account for a major proportion of cases

3. the false positive rate for in vitro testing is approximately six percent

4. genetic testing can now be used to replace in vitro contracture testing

Back 46

ANSWER 1 2 3

1. by the American protocol only, European needs both.

2. RYR1 in 85% of families

3. specificity 94% - Blue book 2005

4. only if the defect has been identified in the proband

Front 47

AM42 ANZCA version [2004-Apr] Q146

In patients with myasthenia gravis

A. aminoglycosides have no effect on the skeletal muscle weakness

B. corticosteroids are useful as first line therapy

C. myocarditis can result in heart block

D. regular plasmapheresis produces long term benefits

E. thyroid function is not altered

Back 47

ANSWER C

A: False
* Aminoglycosides DO cause aggravated skeletal muscle weakness

B: False
* Anticholinesterases (eg. pyridostigmine) are first line

C: True
* Myocarditis can result in AF, heart block or cardiomyopathy

D: False
* Used in crisis or to prepare patient for theatre
* Plasmapheresis can be used as reserved therapy, and is often instituted in patients who have disease progression that is unresponsive to steroids

E: False
* As an associated auto-immune disease...hyperthyroidism is present in approx 10 %

Front 48

AM43 ANZCA version [2004-Aug] Q119, [2005-Apr] Q82, [Jul07]

A 13-year-old boy with Duchenne's muscular dystrophy

A. is at increased risk of malignant hyperthermia

B. is likely to have significant scoliosis

C. is more likely to be cachectic than obese

D. is unlikely to have cardiac involvement

E. may develop rhabdomyolysis when non-depolarising muscle relaxants are used

Back 48

ANSWER B

* A. False - "It is now thought that DMD and other dystrpphinopathies are not associated with malignant hyperthermia", although prolonged exposure to volatiles or sux produces a MH like experience

* B. true - once wheelchair bound (8-12yrs) scoliosis progresses rapidly

* C. no - usually overweight (apparently)

* D. FALSE Cardiac failure often present by age of 6

* E. FALSE - sux and prolonged volatile exposure

Front 49

AM44 ANZCA version [2004-Aug] Q131, [2005-Apr] Q21

Which of the following blood gas results would be consistent with an episode of MH?

A. pH 7.13 pCO2 55 HCO3 18 BE -9.1

B. pH 7.24 pCO2 63 HCO3 26 BE 0

C. pH 7.22 pCO2 30 HCO3 12 BE -13.8

D. pH 7.46 pCO2 45 HCO3 31 BE 7.5

E. pH 7.32 pCO2 44 HCO3 22 BE -3.1

Back 49

ANSWER A

Front 50

AM45 ANZCA version [2005-Apr] Q101, [2005-Sep] Q34

Spinal correction is planned for a twelve-year-old girl with idiopathic scoliosis.

Potential problems associated with this condition include'

A. diabetes insipidus

B. laryngeal abnormalities

C. mitral valve prolapse

D. phaeochromocytoma

E. renal artery stenosis

Back 50

ANSWER C

Mitral valve prolapse has a strong association with idiopathic scoliosis. Its one of the common viva questions when asked about your assessment of scoliosis in a young female patient.

Front 51

AM46 ANZCA Version [Jul06] Q150

Duchenne muscular dystrophy is a contra-indication to the use of

A. corticosteroids

B. non-depolarising neuromuscular blockers

C. suxamethonium

D. tramadol

E. volatile anaesthetic agents

Back 51

ANSWER C

Corticosteroids are the only available treatment, although beneficial effects are modest '

Response to nondepolarizing muscle relaxants is normal

Potent volatile anesthetics have been linked in these patients to massive elevations in creatine kinase, gross myoglobinuria, and cardiac arrest

succinylcholine has been observed to induce severe hyperkalemic cardiac arrest

Front 52

AM47 ANZCA version [2004-Aug] Q139, [2005-Apr] Q31

In patient with with myasthenia gravis presenting for abdominal hysterectomy

A. anticholinesterase therapy will have an effect on her plasma cholinesterase

B. epidural analgesia is contraindicated

C. preoperative sedation should be used

D. there is an increased sensitivity to suxamethonium

E. volatile agents should not be used

Back 52

ANSWER A

Front 53

AM48 [Jul07]

Shown a family tree...

6 year old boy coming for routine operation. Maternal Great Grandfather has had a malignant hyperthermia reaction under GA. Which of the following is most likely to rule out that the 8 year old will NOT suffer a MH reaction

A. 8 year old has negative resting CK level

B. 8 year old has had a previous operation before with no problems

C. mother has had negative genetic testing

D. grandfather has had negative muscles testing

E. father has had an operation before with no problems

Back 53

ANSWER D

Front 54

ANZCA Version [Jul 07] Q.147

A 4y.o. boy presents for insertion of grommets. His maternal great-grandfather is know to have had an episode of malignant hyperthermia. Which of the following
is the strongest evidence that the boy is NOT susceptible to MH?

A. the boy was exposed to halothane at age 2 with no sequelae

B. the boy has recently been shown to have a normal serum creatinine kinase

C. the boy's grandfather has had a negative muscle contracture test for MH

D. the boy's mother has had negative molecular genetic testing for MH

E. there have been NO other episodes of MH in the family despite exposure to known triggers on multiple occasions

Back 54

ANSWER C