Beyond listing the structures you (hopefully) traverse with a spinal needle, it’s not easy to chase down a few facts about this topic without going to the literature, and even that is sparse.
the paramedian approach avoids the ligamentum flavum T/F
the paramedian approach avoids the interspinous ligament T/F
the paramedian approach is made more difficult by calcification in the supraspinous ligament T/F
the first pass success rate of a median approach is greater than that of a paramedian approach in the elderly T/F
the first pass success rate of a median approach is greater than that of a paramedian approach in younger patients T/F
Being born is tough! No wonder newborn infants often have a wizened look to them 😉. Within seconds and minutes of being born huge changes occur to both the cardiovascular and respiratory systems. Some of these changes are irreversible, but the neonate keeps its options open and, for a few days at least, elements of the cardiovascular system can revert to the foetal status, especially if the baby is under physiological stress.
Tomorrow I will do a post on the respiratory changes at birth, but for today we will stick with the cardiovascular. Most physiology textbooks will cover this topic, Power and Kam’s book gives quite a detailed account, and here is a link to an article in the BJA Education on the topic (be mindful that there is an erratum published – I hope that shows in the link). It is a good idea to revise the foetal circulation before tackling this topic (there is a section on that in the above article)
SS_PA 1.22 Describe the circulatory and respiratory changes that occur at birth
SS_OB 1.3 Describe the transition from foetal to neonatal circulation and the establishment of ventilation
Loss of the placental circulation at birth results in both an increase in the neonate’s systemic vascular resistance and a fall in pulmonary vascular resistance T/F
Neonatal pulmonary vessels have the capacity for hypoxic pulmonary vasoconstriction T/F
The ductus arteriosus closes within minutes of birth, preventing any L to R shunting of blood T/F
Cardiac output in the hours after birth is substantially lower than it is at 8 weeks of age T/F
A newborn’s cardiac output is sensitive to changes in heart rate T/F
A newborn infant will often respond to hypoxia by becoming tachycardic, to improve cardiac output T/F
SS_OB 1.6 Describe the changes in the anatomy of the maternal airway and their impact on airway management during anaesthesia.
SS_OB 1.1 Describe the physiological changes and their implications for anaesthesia that occur during pregnancy, labour and delivery.
The increased risk of airway bleeding during manipulation is primarily due to platelet dysfunction in pregnancy. TRUE/FALSE
Lung compliance decreases in pregnancy. TRUE/FALSE
Closing capacity increases during pregnancy. TRUE/FALSE
Oxygen consumption is increased at term, regardless of whether the patient is in labour or not. TRUE/FALSE
Airway oedema can occur due to venous engorgement from labour. TRUE/FALSE
SS_OB 1.7 Describe the changes in the anatomy of the maternal vertebral column, the spinal cord and meninges relevant to the performance of a central neuraxial block including epidural, spinal and combined spinal-epidural, with appropriate surface markings
TRUE/FALSE The risk of inadvertent venous puncture, with epidural placement in pregnant women, is the same as in the non-pregnant population
TRUE/FALSE The line joining the iliac crests (Tuffier’s line) may transverse the body of L5 in late pregnancy
TRUE/FALSE Epidural space pressure may be positive during labour
TRUE/FALSE Epidural veins are engorged in late pregnancy
TRUE/FALSE The ligamentum flavum softens during pregancy
Previously examined SAQs are a useful study tool. We’ll work through the February 2017 paper for the next couple of weeks.
Question 1 was quite a visual question asking about the anatomy relevant to LIJ line placement.
BT_GS 1.72 BT_RT 1.20
The vagus nerve is in the carotid sheath TRUE/FALSE
The glossopharyngeal nerve is in the carotid sheath TRUE/FALSE
Pneumothorax is more likely with LIJ placement than RIJ TRUE/FALSE
The carotid pulse is lateral to the LIJ TRUE/FALSE
The LIJ has a greater calibre than the right TRUE/FALSE
The turbinates project into the nasal cavity from the nasal septum. TRUE / FALSE
When a curved laryngoscope blade is placed in the vallecula, it elevates the epiglottis by tensing the hyoepiglottic ligament. TRUE / FALSE
In an adult, cricoid pressure blocks the oesophagus by compressing it against the C3 vertebral body. TRUE / FALSE
The sensory innervation of the area just above the vocal cords is from the external branch of the superior laryngeal nerve. TRUE / FALSE
The surface landmark that corresponds with the carina is the manubriosternal joint (angle of Louis). TRUE / FALSE
I had a Bier’s block for my recent operation – old fashioned, very effective and not examinable in the primary exam😉. I’ve already asked some statements related to local anaesthetics and nerve conduction, so today some statements related to pain pathways.
BT_PM 1.1 Describe the anatomy of the sensory pathways with particular reference to pain sensation
The spinothalamic tracts are in the dorsal column TRUE/FALSE
Primary afferent neurons synapse in the dorsal root ganglion TRUE/FALSE
C-fibres synapse in the substantia gelatinosa TRUE/FALSE
Pain and temperature fibres decussate at the level of the medulla TRUE/FALSE
C-fibres are unmyelinated TRUE/FALSE
Oops, looks like we haven’t had any anatomy for a while.
SS_PA 1.1 Describe the anatomy of the neonatal airway, how this changes with growth and development and the implications for airway management
TRUE/FALSE Under extension of the neck may cause airway obstruction in the neonate
TRUE/FALSE Over extension of the neck may cause airway obstruction in the neonate
TRUE/FALSE Infants are obligate nasal breathers
TRUE/FALSE Neonates have a large tongue in comparison to the oropharynx
TRUE/FALSE Infants are unable to breathe via the mouth
After I intubated my first patient yesterday, blood started coming up the endotracheal tube. On bronchoscopy there was granulomatous tissue extending down the entire trachea… Which inspired me to post an airway anatomy LO.
IT_AM 1.1 Describe the basic structural anatomy of the upper airway including the larynx
TRUE/FALSE The cricoid is the only complete cartilaginous ring in the tracheobronchial tree
TRUE/FALSE The vocal cord is formed by the superior edge of the cricothyroid membrane
TRUE/FALSE The recurrent laryngeal nerve supplies all the intrinsic muscles of the larynx
TRUE/FALSE The superior laryngeal nerve is purely sensory
TRUE/FALSE The posterior cricoarytenoids are the only muscles that open the glottis
The patient had a grade III larynx on DL. The ENT surgeon suggested the granulation tissue might have been related to the use of a bougie when the patient was intubated a month or so ago. Perhaps the rigid plastic bougies are more traumatic than we realise.