Malignant Hyperthermia

Question 1

2 things that trigger MH

Answer 1

Volatile anesthetic agents

Sux

Question 2

What happens in MH

Answer 2

Uncontrolled increase in oxidative metabolism in skeletal muscle

Question 3

What kind of genetic disorder is MH?

Answer 3

Autosomal dominant disorder

Question 4

When does MH occur?

Answer 4

Upon or shortly after exposure to certain general anesthetic agents

Question 5

9 typical signs of MH:

Answer 5

1. Hyper catabolic state
2. High temp
3. Tachycardia
4. Tachypnea
5. Hypercarbia
6. Hypoxia
7. Muscle rigidity
8. Mixed acidosis
9. Rhabdomyolysis

Question 6

4 1st signs of MH:

Answer 6

Hypoxia
Hypercarbia
Sinus tachycardia
Massager spasm

Question 7

Most common pattern of MH:

Answer 7

Respiratory acidosis and muscular abnormalities

Question 8

EtCO2 suspect of MH:

Answer 8

> 55

Question 9

Arterial pCO2 suspect of MH:

Answer 9

> 60

Question 10

Arterial pH suspect of MH:

Answer 10

<7.25

Question 11

Percent of respiratory acidosis, metabolic acidosis, and muscular abnormalities

Answer 11

99%
26%
80%

Question 12

Suspect of MH by monitor with pulse ox, capnography, temp

Answer 12

99. 3%
100. 2%
101. 9%

Question 13

Percent of MH with use of only sux

Answer 13

.7

Question 14

Percent of MH with use of sux and volatile

Answer 14

53.9

Question 15

Percent of MH with use of only volatile

Answer 15

45.1

Question 16

Percent of MH with no sux or volatile

Answer 16

.4

Question 17

5 steps to treatment of MH

Answer 17

1. Declare MH
2. Discontinue triggering agents
3. Abandon machine
4. 100% O2 at high flow
5. Give dantrolene

Question 18

• Postsynaptic muscle relaxant that lessens excitation-contraction coupling in muscle cells
• inhibits Ca++ ions release form SR stores by antagonizing ryanodine receptors

Answer 18

Dantrolene

Question 19

Primary drug used to treat and prevent MH

Answer 19

Dantrolene

Question 20

Amount of minimum stock of dantrolene in hospitals

Answer 20

36 vials

Question 21

Dantrium/revonto amount should be in each institution

Answer 21

36 vials

Question 22

Ryanodex amount should be in each institution

Answer 22

3 vials

Question 23

Percent of release rate for MH

Answer 23

19%

Question 24

Systemic activation of blood coagulation, which results in generation and deposition of fibrin, leading to microvascular thrombi in various organs and contributing to multi organ dysfunction syndrome

Answer 24

Disseminated intravascular coagulopathy (DIC)

Question 25

How to avoid MH complications?

Answer 25

Give dantrolene early and need to control temp

Question 26

For every 30min increase in interval between 1st MH sign and 1st dantrolene dose, complication likelihood increased:

Answer 26

1.6x

Question 27

For every 2degree C in max temp, the complication likelihood increased:

Answer 27

2.9x

Question 28

6 key pt stability indicators

Answer 28

1. EtCO2 declining or normal 2. HR is declining or normal 3. No dysrhythmias 4. Temp is declining 5. Resolved muscular rigidity 6. IV dantrolene administered

Question 29

Dedicated anesthesia machine that has never been exposed to volatile anesthetic agents, or disposable non-rebreathing circuit

Answer 29

Virgin machine

Question 30

How to make old machine a virgin machine:

Answer 30

O2 10L/min for 104min

Question 31

How to make new machine a virgin machine:

Answer 31

O2 10L/min for 20min

Question 32

During the case, what should the FGF be kept at to avoid ‘rebound phenomenon’?

Answer 32

10L/min

Question 33

What filters remove anesthetic gases and obviate the need for purging the system?

Answer 33

Charcoal filters

Question 34

What will still need to be done with charcoal filters?

Answer 34

FGF 10L/min for 90sec prior to placing the filters on BOTH inspire and expire ports

Question 35

What to do in an MH emergency?

Answer 35

Abandon machine in favor of Ambu bag and administer TIVA