The Internet Journal of Anesthesiology

Questions and Answers

by Olivier C. Wenker, M.D.

Part 9

Introduction: This site was created in order to stress your brain for a few minutes (3 questions) while surfing by. Every once in a while we will update this section with new questions and answers. This will give you the opportunity to check your knowledge in different anesthesiologic fields. If you would like to be informed whenever we update this section please subscribe for free as reader of  The Internet Journal of Anesthesiology.

Disclaimer: One should keep in mind that the current opinion in Europe may differ from the one in Australia or in the U.S. Having an international readership, it might be difficult to satisfy everybody with the given answers or the suggestions for additional reading. In order to assure the accuracy of this section, all the questions and especially the answers will be reviewed by several international members of the editorial board. Nevertheless, it is difficult to ensure that all the information given is entirely accurate for all circumstances. The publishers disclaim any liability, loss, or damage occurred as consequence, directly or indirectly, of the use and application of any of the content of this section.

Question 1:

How will a patient with myasthenia gravis react to muscle relaxants (paralizing agents) ?

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Question 2:

1. What does this thrombelastogram show?

2. What would be your treatment?

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Question 3:

What monitoring devices can be used to detect venous air embolism ?

 

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Answers

Answer to Question 1:

• Depolarizing agents: Succinylcholine needs to bind to the neuromuscular junction in order to take effect. In myasthenia gravis, the number of functioning receptors at the neuromuscular junction is decreased. Therefore, the patient might develop a relative resistance to depolarizing agents such as succinylcholine.
• Non-depolarizing agents: Patients with myasthenia gravis demonstrate a higher sensitivity for non-depolarizing agents. They should be administered at a lower dose and rate. Prolonged muscle relaxation may require postoperative ventilation.

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Answer to Question 2:

• A pathological thrombelastogram (TEG) ®: alpha and MA are small: Weak Clott Formation indicative of hypofibrinogemia and/or
  thrombocytopenia/poor platelet function.
  
  To learn more about interpretation of TEG's ® please go to: Wenker O, Wojciechowski Z, Sheinbaum R, Zisman E: Thrombelastography. The Internet Journal of Anesthesiology 1997; Vol1 N3: http://www.ispub.com/journals/IJA/Vol1N3/teg.htm. Published July 1, 1997; Last Updated July 1, 1997.

• Treatment: Requires administration of FFP, platelets and possible cryoprecipitate. Adding c7E3 Fab (REOPRO) to the TEG ® sample will eliminate platelet function from the TEG ® tracing. The MA will become a function of fibrinogen activity. Low fibrinogen activity can be corrected by administration of cryoprecipitate or FFP.
  A repeat TEG ® should be performed post treatment. 

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Answer to Question 3:

The devices able to detect venous air embolism are listed according to their sensitivity in decreasing order:

1. Transesophageal echocardiography
2. Thransthoracic doppler
3. End-tidal nitrogen (ET-N2)
4. End-tidal carbon dioxide (ET-CO2)
5. Central venous catheter / Pulmonary artery catheter
6. Esophageal stethoscope

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© Internet Scientific Publications, L.L.C., 1996 to 1999.

First Published: October 1996

The Internet Journal of Anesthesiology