Questions and Answers

Question and Answers^*

Preguntas y respuestas

Fernando Raffán-Sanabria^a,b

^a Intensive Care Anaesthetist, Fundación Santa Fe de Bogotá University Hospital, Bogotá, D.C., Colombia
^b Professor, Universidad del Bosque y Universidad de los Andes, Bogotá, D.C., Colombia

^* Please cite this article as: Raffán-Sanabria F. Preguntas y respuestas. Rev Colomb Anestesiol. 2016;44:81-82.

1) In paediatric patients, the optimal injection site for the infraclavicular approach (ICA) to the brachial plexus is still a subject for debate. Of the following statements, which is false:

1. Its disadvantages include a lower probability of blocking the axillary nerve and the cutaneous muscle, compared to the axillary approach.
2. When single injectionsPu are used, there is a higher probability of inadequately blocking the posterior cord.
3. The consistency between the modified Wilson coracoid infraclavicular approach and ultrasound for determining the ideal puncture site is low.
4. Weight and height are independent factors for determining the distance between the coracoid process and the posterior cord both in adduction as well as in abduction.

2) Regarding the stellate ganglion, all of the following statements are true, except:

1. In nearly 80% of the general population, the stellate ganglion forms from the fusion of the inferior cervical ganglion with the first thoracic ganglion.
2. It is found medial to the scalene muscles, lateral to the longus coli muscle, oesophagus and trachea, by the recurrent laryngeal nerve.
3. One of the indications for blocking the stellate ganglion is management of prolonged QT interval syndrome.
4. A complication associated with its blockade may be dysphonia and a sensation of dysphagia because of the block to the superior laryngeal nerve.

3) Horner's syndrome is an unpleasant effect of stellate ganglion blockade consisting of:

1. Mydriasis, tearing and enophthalmos
2. Myosis, ptosis and enophthalmos
3. Myosis, ptosis and transient hoarseness
4. Mydriasis, enophthalmos and transient hoarseness.

4) Distal innervation to the malleoli is supplied by the following nerves, except:

1. Superficial peroneal nerve
2. Deep peroneal nerve
3. Sural nerve
4. Anterior tibial nerve

5) The only nerve that arises from the lumbar plexus is:

1. Tibial nerve
2. Deep peroneal nerve
3. Saphenous nerve
4. Sural nerve

6) The use of ultrasound for ruling out the diagnosis of pneumothorax has a negative predictive value of almost:

1. 100%
2. 80%
3. 65%
4. 50%

7) The "barcode sign" seen on ultrasound is found in patients with a diagnosis of:

1. Pulmonary oedema
2. Pneumothorax
3. Pneumonia
4. Pulmonary thromboembolism

8) Over the past few years, the use of ultrasound has become a useful tool for the diagnosis and management of airway problems. Of the following statements, which is false:

1. Tracheal cartilages are hyperechoic just like the cricothyroid membrane and the vocal cords.
2. The main bony structure in the airway is the hyoid bone.
3. The thyroid cartilage is seen as a hypoechoic structure in relation to the vocal cords and it is one of the structures best visualized under ultrasound.
4. Some studies, like the one by Ezri et al., have used pre-tracheal fat assessment at the level of the vocal cords as a predictor of a difficult airway.

9) With the use of ultrasound for predicting post-extubation stridor, a risk factor has been found to be an end-to-side diameter of the air column of less than:

1. 3.5 mm
2. 4.5 mm
3. 5.5 mm
4. 6.5 mm

10) Regarding the measurement of the optic nerve and its correlation with intracranial hypertension (ICH), it is true that:

1. Measurement of the optic nerve sheath diameter through an ocular window may be a non-invasive method for detecting ICH.
2. By way of a learning curve, 30 measurements with 10 abnormal scans are proposed for a physician with experience in ultrasound.
3. The cut-off point for the scan to be considered positive for ICH is 10mm.
4. The most distal portion of the optic nerve is lined by the arachnoid and, as intracranial pressure rises, the cerebrospinal fluid spreads along the arachnoid membrane towards the optic nerve sheath.

Answers

1) a
2) d
3) b
4) d
5) c
6) a
7) b
8) a
9) b
10) a

Reference

Revista Colombiana de Anestesiología. Rev Colomb Antestesiol. 2015;43:261–369.         [ Links ]