Anatomy Flashcards
1
Q
The RCA supplies what distribution of the RV? What about SA node and AV node?
A
Anterior, lateral, inferior, and posterior, but the apex of the RV is supplied by LAD. SA and AV most of the time
2
Q
What does the RCA supply on the left side?
A
Posterior and inferior walls of the LV, posterior 1/3 of the IV septum, sometimes the apex of the LV, and portions of the right and left bundle branches.
3
Q
Why would occlusion in LAD NOT affect posterior base of the LV?
A
Because most blood from inferior and posterior LV is supplied by the PDA which arises from RCA 85% of time, or the LCX.
4
Q
What does the LAD supply?
A
Anterior LV, apex RV, usually apex LV, anterior 2/3 of RV septum
5
Q
What is promethazine?
A
A dopamine antagonist used for treating nausea.
6
Q
How to treat NAUSEA and vomiting from sympathetic block via neuraxial?
A
Atropinenoe gkucopyrolate because sometimes the nausea is from actual gut contraction and NOT hypotension. Look at what the question is asking you-is it asking you to treat hypotension or nausea related to the spinal?
7
Q
What exactly is ankylosis spondylitis? What HLA is it associated with? Is it associated with peripheral neuropathy? most extra-articulations joint issues are related to what?
A
It is an inflammatory disease of the axial spine. HLAB-27. It is NOT associated with peripheral neuropathy. Extra-articulations joint issues are related to the EYE, with uveitis being common.
8
Q
Why are people with Ankylosing spondylitis difficult to intimate, ventilate, and associated with spinal hematoma?
A
Decreased cervical spine ROM=difficult intubation
TMJ hypomobility=ill sealed faemask
Epidural hematoma-can happen with increased attempts due to ossification of ligaments
9
Q
The musculocutaneous nerve travels where, and innervated what? (Motor and sensory)
A
Travels in corachobrachialis muscle and innervates lateral forearm. It provides motor innervation to biceps brachii, coracobrachialis, and brachialis muscle.
10
Q
What two things are NOT in the axillary sheath?
A
No axillary vein or misculocutaneous nerve. The median, ulnar, and rdial neeves are in there as well as the axillary artery.
11
Q
What is the LCFN-where does it originate, and what sensation does it provide? Landmark for this block?
A
Branches from L2-L3 nerve roots, sensory innervation to anterolateral thigh. ASIS is a starting landmark-go 2.5 cm medial, ad 2.5 cm below
12
Q
Why are interscalene blocks so great for shoulder surgeries?
A
Because they block the entire plexus plus the suprascapikar nerve which supplies sensation to the shoulder.
13
Q
Brachial plexus is formed by what? And innervates what when it comes to the shoulder, but misses something else?
A
C5-T1, all motor and sensory innervation to the shoulder except the supraclavicukar nervevwhich supplies skin on shoulder.
14
Q
BP roots: ___, which give rise to
A
C5-T1
Give rise to three trunks (superior, middle, and inferior)-which emerge between the scalene muscles
15
Q
Why is IS block not recommended for hand surgery? Hoarseness after IS block?
A
Because it can miss the inferior trunk- Ulnar nerve
Hoarseness due to recurrent laryngeal nerve blockade
16
Q
What nerve is blocked by putting local in the palatoglossal fold?
A
Glossopharyngeal
17
Q
How is the recurrent laryngeal nerve blocker?
A
Transtracheal injection through the croci thyroid membrane.
18
Q
How is the superior laryngeal nerve blocked?
A
Injection at the horn of the hyoid bone or placing a pledger in the purified sinus.
19
Q
Explain SIME
A
Superior laryngeal nerve has 2 branches-sensation ABOVE the trachea is provided by the internal branch, and motor (to the cricothyroid) is provided by the external branch.
20
Q
Median nerve-sensation and motor:
A
Sensation in MEDIAL forearm, wrist flexion
21
Q
Radial nerve-sensation and motor
A
Sensation in dorsal hand, wrist extension
22
Q
what kind of block would you be doing if you touched Chassaignac’s tubercle? what does that even mean?
A
alpation of Chassaignac’s tubercle (the anterior tubercle of the transverse process of the C6 vertebra) which is located between the sternocleidomastoid muscle and the trachea
23
Q
common side effects of stellate ganglion block?
A
Common effects that are noted upon a successful stellate ganglion block are a result of the iatrogenic sympathectomy to the ipsilateral face. These include, but are not limited to: Horner’s syndrome (ptosis (A), miosis (B), and anhidrosis), injected conjunctiva (D), increased skin temperature (C), nasal congestion, and vasodilation
24
Q
signs of an epidural hematoma:
A
An epidural hematoma is associated with a dull aching back pain that is progressive and associated with progression of neurological symptoms. There is the progression of sensory loss followed by motor loss. Partial block resolution followed by block progression without bolus suggests hematoma. Diagnosis of an epidural hematoma is made with emergent MRI
25
allergy to local anesthetics? which ones more commom?
| methylparaben vs PABA:
True allergic events with local anesthetics are rare. The pH of injectate does not change the incidence of allergic reaction. Allergic reaction with ester type local anesthetics (e.g. procaine, benzocaine, tetracaine) most often occurs because of hypersensitivity to para-aminobenzoic acid (PABA). PABA a metabolite of ester local anesthetics. Allergic reaction to amide anesthetics is rarer than with esters and is likely a result of allergy to preservatives in solution. One preservative used for amide anesthetics is methylparaben, which can also be metabolized to PABA
26
Bicarbonate-why would anyone add it to a solution?
Often bicarbonate is added to local anesthetic (often in a 1:10 ratio) to increase the pH of the solution. This increase of pH decreases pain on injection into peripheral tissues and also speeds the onset time of the local anesthetic by increasing the unionized portion of local anesthetic. Lidocaine remains relatively soluble in its unionized form. However ropivacaine and levobupivacaine are not, and therefore it is not recommended to have bicarbonate added for infusions. Recommendations for ropivacaine state that if bicarbonate is added the solution should be used within 5-10 minutes of mixing.
27
where is the brachial plexus in relation to the subclavian artery?
The brachial plexus lies lateral, superior and posterior to the ScA.
28
best possible practice to use to prevent PDPH (needle wise)
Use of the smallest possible (e.g. 27-gauge) non-cutting needle for spinal placement is likely the best practice to avoid PDPH. quincke over cutting
29
T/F-aggressive hydration prevents PDPH
false-it does not PREVENT it
30
which nerves supply the knee (sensory)?
femoral and sciatic
31
Femoral nerve comes from? what does it provide sensation to?
The femoral nerve emerges from the lumbar plexus and is formed by L2-L4.Its anterior branch supplies sensation to the anterior and medial aspects of the thigh and further distal it gives rise to the saphenous nerve, which supplies the medial aspect of the leg below the knee-joint.
32
Obturator nerve and LFCN-what do they supply?
The other major branches of the lumbar plexus are the genitofemoral, lateral femoral cutaneous, and obturator nerves. The obturator nerve gives innervation to the skin of the medial aspect of the thigh. In some patients, it gives innervation to a small area of the knee and the addition of this nerve block can sometimes help with intraoperative and postoperative analgesia. Because it innervates the medial thigh, blocking the obturator nerve can also help patients tolerate tourniquet pain. The lateral femoral cutaneous nerve provides sensation to the lateral aspect of the thigh above the knee. Although it does not provide sensation to the knee in most individuals, blockade of this nerve does help patients tolerate tourniquet pain during the procedure.
33
sciatic nerve-where does it come from, what does it supply?
The sciatic nerve originates from the sacral plexus and is the combination of nerve roots L4-S3. It courses through the leg along the posterior thigh and then divides into the common peroneal and tibial nerves a little over halfway down the femur. The sciatic nerve and its branches supply sensation to the back of the thigh and knee as well as the entire lower leg, except for the medial portion which is supplied by the saphenous nerve
34
what is Raynaud's and how would a block affect it?
blood vessels constrict with cold or stress, so a block would relieve this
35
risk factors for PDPH. does approach, or loss of resistance technique matter?
Other patient-related risk factors include history of previous PDPH (2.3 times more likely), history of air travel, and patients with a BMI < 30. Obese (BMI > 30) patients tend to be less susceptible to PDPH which is attributed to increased abdominal pressures which may reduce CSF leakage. Approach (midline vs. paramedian) and loss of resistance technique (air vs. saline for epidural placement) do not alter PDPH incidence.
36
What does a lumbar plexus block block? what does it spare?
A LPB reliably blocks the femoral, lateral femoral cutaneous, and obturator nerves. It spares the sciatic nerve, though the commonly-used posterior approach for a LPB allows for easy access to the sciatic nerve for a separate block.
Sciatic is spared, so foot and ankle movements spared with LPB including, but not limited to the gastrocnemius, soleus, plantaris, and digital flexors) that allow plantar flexion at the ankle.
37
obturator motor;
Hip adductionincluding the adductor longus, brevis, and magnus muscles)
38
Femoral nerve motor
Blockade of the femoral nerve will prevent hip flexion (as it innervates the iliopsoas and quadriceps femoris muscles) and extension of the lower leg at the knee (quadriceps femoris muscles)
39
Does the site of IV affect the Bier block?
the site of IV placement and injection does not affect the block efficacy
40
How does a bier block work?
A Bier block provides extremity anesthesia by diffusion of local anesthetic from the veins into the capillaries and vasa nervosa surrounding the peripheral nerves. Local anesthetic also diffuses extravascularly into the nerves supplying the skin. Ischemia caused by the tourniquet also causes a degree of anesthesia by impairing nerve conduction.
41
V2 of trigeminal nerve covers which things?
The sphenopalatine ganglion derives the bulk of its innervation from the maxillary branch (V2) of the trigeminal nerve and provides innervation to the nasal cavity mucosa, hard palate, and lacrimal gland.The infraorbital nerve is also derived from the maxillary branch of the trigeminal nerve, but it is mainly responsible for innervation of the lateral aspect of the skin overlying the nose, cheek, and upper lip
42
What makes up femoral triangle? whats inside the femoral triangle?
The femoral triangle includes the femoral nerve, femoral artery, femoral vein, lymphatics, and pubic symphysis. The adductor longus muscle makes the medial aspect of the triangle and the inguinal ligament comprises the superior border of the triangle.The sartorius muscle creates the lateral border of the triangle
43
Twitch monitor and femoral nerve block:
When a twitch monitor is used during a femoral nerve block, the quadriceps femoris is likely to contract with subsequent twitching of the patella - this is regarded to be adequate stimulation correlating to appropriate femoral nerve block
44
What is TNS? Risk factors?
Transient neurologic syndrome can occur following spinal anesthesia and is defined as back pain with radiation of pain to the buttocks, thighs, hips, and calves, occurring within 24 hours after recovery from an otherwise uneventful spinal anesthetic. These symptoms typically last 1-3 days but neurophysiologic evaluation fails to show pathologic findings. Symptoms usually resolve spontaneously without further intervention.
The only factors found to be associated with increased risk of TNS are lidocaine spinal anesthesia, the lithotomy position, and ambulatory surgery with early ambulation. Pooling and maldistribution of hyperbaric local anesthetic encountered with the use of pencil-point spinal needles or spinal microcatheters are suggested to have a causative effect for neurological injury (cauda equina syndrome), but not TNS. Baricity of local anesthetics is not associated with the development of TNS following spinal anesthesia.
45
twitch monitor stuff-which current do you want to use?
Since the charge (Q) required to cause depolarization is inversely proportional to the square of the distance (r) between the needle and the nerve (Q α 1/r2), the ability to elicit the desired response (e.g. twitch) at a very low current indicates the needle is very close to the nerve. Accordingly, a block has a high success rate when the desired response is elicited with a stimulating current of 0.4-0.5 mA. However, if the response occurs with a current < 0.3 mA, the needle may be intraneural which may increase the risk for block complications without necessarily increasing the block success rate.
46
twitch monitor-connecting to red vs black-
Connecting the cathode lead (black, current flows from the cathode) of the nerve stimulator to the needle allows the desired response to be achieved using a lower (1/4 to 1/3) current than if the anode lead (red, current flows towards the anode) were connected to the needle. This is the standard against which the desired 0.4-0.5 mA current was determined. Accordingly, if the leads were accidentally switched (anode attached to needle), when a response is still elicited at 0.4 mA, this likely indicates that the needle is intraneural instead of just outside the nerve. This phenomenon occurs because a cathode needle “injects” current and causes nerve depolarization whereas stimulation with an anode needle leads to hyperpolarization.
47
twitch monitor stiff-sine vs square wave, and insukated vs uninsukated needle?
you want to use square, and an insulated needle only disperses current from its tip and with a greater current density relative to an uninsulated needle
48
Intercostobrachial nerve-when would you block it? It comes from what?
The intercostobrachial nerve supplies sensory innervation to the inner aspect of the upper arm. It may be anesthetized to prevent tourniquet-induced pain of the medial upper arm following otherwise adequate regional anesthesia to the upper extremity.comes from T2 and T1
49
TAP block nerves blocked:
The nerves affected by transversus abdominis plane block include the intercostal, subcostal, ilioinguinal, and iliohypogastric nerves.
50
peribulbar vs retrobulba blocks. what doees retrobulbar not block?
Peribulbar blocks are associated with a lower incidence of complications like retrobulbar hematoma. The decrease in complications, like retrobulbar hematoma and globe puncture, is the reason why peribulbar blocks may be preferred over retrobulbar blocks. Peribulbar block uses more local anesthetic. peribulbar can have chemosis. peribulbar happens farther back.
The retrobulbar block does not block the orbicularis oculi or levator palpebrae muscle. Therefore, an additional injection to block the facial nerve is required, such as the Van Lint block. The retrobulbar block is associated with a lower incidence of chemosis. retrobilbar has a higher incidence of hematoma
51
oculocardiac reflex: what branches?
The oculocardiac reflex may be provoked during ophthalmic surgery. The afferent limb of the oculocardiac reflex is the trigeminal nerve, ophthalmic branch (CN V1), via the ciliary ganglion. The efferent limb is the vagus nerve (CN X), where pressure or traction on the eye can lead to bradycardia and even asystole. The reflex is more common in young individuals and during strabismus surgery.
52
Sural nerve is a branch of:
branch of sciatic-covers lateral leg and thigh
53
Which nerves are blocked i the ankle block? which other 2 blocks can combine to do the same thing?
To provide complete anesthesia/analgesia, all five nerves to the foot must be blocked: posterior tibial, common peroneal, deep peroneal, sural, and saphenous nerves. Alternatively, the sciatic (popliteal fossa) block and the saphenous nerve block may provide the same distribution of neural blockade.
54
What is the McConell sign on TEE?
TEE can be suggestive of PE by the presence of regional wall motion abnormalities sparing the right ventricular apex (McConnell sign).
55
Aortic aneurysm vs dissection on imaging:
Aortic aneurysm would show a dilated aorta and would not show an intimal flap dissecting the aorta
56
when using a nerve stimulator for ISB, what do you want to see twitch?
When using a nerve stimulator, the desired motor response is twitching of the pectoralis, deltoid, arm, forearm, or hand muscles.
57
If you get a diaphragmatic response when doing ISB, where does needle need to move?
Diaphragmatic stimulation during ISB using a nerve stimulator indicates phrenic nerve stimulation. The needle should be redirected posteriorly to achieve the desired nerve blockade
58
twitches expected in femoral block, if the sartorius alone twitches, what should you do?
The end-point of a femoral nerve stimulation should be a patellar twitch, which on occasion may be accompanied by a sartorius twitch and would still be acceptable. However, if a sartorius twitch without patellar twitch is elicited, the needle should be redirected deeper and lateral.
59
If epidural fragment is retained, what are you going to do about it (imaging wise), and what about what you'll actually do?
The diagnostic test of choice for a retained epidural catheter fragment is computed tomography. Minor fragments may be left in place if they do not cause symptoms. Neurosurgical consultation should be considered for any symptomatic retained fragment or any fragment within the spinal canal.
60
TEE imaging: is RV anterior? where is the non-coronary cusp located? Look at photo.
Right ventricle is an anterior structure, as is the right coronary cusp. The non-coronary cusp is always located next to the inter-atrial septum.
okay
61
Foot eversion and dorsiflexion? is controlled by which nerve?
Foot eversion is controlled by peroneal nerve.
62
Landmarks of popliteal block (posterior approach)
The landmarks for this approach are the biceps femoris laterally, semimembranosus medially, and the two heads of the gastrocnemius inferiorly.
63
Twitch of the tibial nerve results in:
tibial nerve results in plantarflexion and inversion of the foot
64
Tell me about the lateral popliteal nerve approach.
A second approach to the sciatic nerve is the lateral popliteal approach with the patient supine and the knee flexed to 90 degrees. A spot 7-8 cm (depending on the source) cephalad to the lateral epicondyle of the femur is located in a groove between the vastus lateralis and biceps femoris muscle. A needle is inserted at 90 degrees to the long axis of the leg until the femur is contacted. The needle is redirected posterior until a tibial nerve twitch is noted. During needle advancement the biceps femoris muscle will twitch and serves as a marker for nerve depth. The nerve should be within 2 cm of the cessation of the biceps femoris twitch, if not, no further needle advancement should commence given the medially located popliteal vessels and slight redirection of the needle posterior is needed. If a vastus lateralis muscle twitch is observed then the needle needs to be redirected posterior as the vastus lateralis muscle is the anterior anatomic landmark in the performance of this block. The success and distribution of blockade between the two techniques is similar.
65
How does spinal anesthesia result in hypotension?
Spinal anesthesia causes a sympathectomy that often results in hypotension via three main mechanisms: arterial dilation (decreased afterload), venodilation (decreased preload), and bradycardia (parasympathetic dominance and/or the Bezold-Jarisch reflex).
66
What is an elevated fractional area change?
An elevated fractional area change correlates with an above normal ejection fraction and increased cardiac output, which is not associated with spinal anesthesia.
67
What is the Bezold-Jarisch reflex? How does it differ from the carotid baroreceptor reflex?
This parasympathetic-mediated reflex occurs when stretch receptors located mainly in the left ventricle respond to an acute decrease in left ventricular preload. The result is bradycardia and reduced contractility (and resultant hypotension). This reflex is thought to occur to allow the ventricle additional time to fill and increase preload. Normally, the carotid sinus baroreceptor response to hypotension (increased heart rate and contractility) dominates, but in the setting of an acute drop in ventricular preload (e.g. spinal anesthetic or nitrate use), the Bezold-Jarisch reflex may occur before the carotid sinus reflex.
68
Explain manual in-line stabilization:
| Minimal manipulation of:
This technique is accomplished by having two operators maintain the head, neck, and shoulders in a neutral position while the laryngoscopist intubates the tracheaThe first operator stabilizes the head and neck in a neutral position by grasping the mastoid processes with their fingertips and cradling the occiput with the palms of their hands. The second operator stabilizes both shoulders by holding them against the OR table, bed, or stretcher.
Minimal manipulation of mid cervical spine
69
Cervical spine injury can be cleared once ALL of which things are met?
1. No midline cervical tenderness 2. No focal neurological deficit 3. Normally alert 4. Not intoxicated 5. No distracting painful injury.
70
What is the most appropriate test to differentiate between cSF and saline? Why/
A point of care glucose test strip is the most appropriate test to differentiate cerebral spinal fluid from normal saline. The reliability and speed of the point of care glucose strip make it the most appropriate test for differentiating dural puncture from loss-of-resistance saline return.
71
Nerve thing in photo
(Starting from medial) Men, underestimate, real
72
Which nerves are blocked by axillary block? What is an axillary block good for? What nerve is usually missed in an axillary block?
Axillary nerve blocks provide excellent analgesia to structures of the upper extremity that lie distal to the elbow. Axillary block covers radial, median, and ulnar nerve. Musculocutaneous nerve is usually missed.
73
What are the landmarks for an infra-gluteal sciatic nerve block?
ischial tuberosity, greater trochanter of the femur, and sciatic groove
74
Sciatic nerve block photo:
Okay
75
Achondroplasia and airway-what are you concerned with?
When planning for airway management in a patient with achondroplasia, atlantoaxial instability is the greatest concern.
76
Sensation to the eye is provided by the ophthalmic nerve via _____.
Do you also have to block the facial nerve-why or why not?
long and short posterior ciliary nerves.
Since the orbicularis oculi muscle is innervated by the facial nerve, this results in the potential for eye movement during surgery unless that is blocked separately
77
Five and dime reflex:
Oculocardiac reflex: “five and dime” reflex – it starts in the fifth cranial nerve (trigeminal) and exits the tenth cranial nerve (vagus)
78
The obturator block is performed by injecting local anesthetic between ____ or ___
between the adductor longus and brevis muscles.
OR
between the adductor brevis and adductor magnus muscles-if you do the second, that will take away motor-which you don't want
79
P2 valve is most likely to become ischemic due to
single vessel blood supply
80
The mnemonic ALABAMa is used to remember
muscles from superficial to deep: Adductor Longus, Adductor Brevis, Adductor Magnus.
81
Obturator sensory vs motor:
anterio-sensory and motor
| posterior-motor alone
82
What does the median nerve supply (motor and sensory)? If it was missed in an axillary block, then where can it be blocked?
The sensory distribution of the median nerve is in the palm of the hand and its motor distribution provides flexion of the wrist. If the median nerve is missed, it can be blocked either at the level of the elbow or the wrist. At the elbow, the median nerve lies medial to the brachial artery in the antecubital fossa. The block is performed by inserting the needle just medial to the brachial pulse and can be performed with the aid of ultrasound, nerve stimulator, or paresthesias. At the wrist, the median nerve is located just lateral to the palmaris longus. A supplemental block can be performed at either of these sites, but since this patient is having wrist surgery, blocking the nerve at the elbow makes the most sense.
83
What does sux do to LES tone? What about cricioid pressure? When is cricoid pressure contraindicated?
Sux increases LES tone,
Cricoid pressure decreases LES tone
Cricoid pressure is contraindicated with cervical spine and laryngeal fracture as well as active vomiting as the risk of esophageal rupture is increased.
84
Complete vs partial bilateral nerve injury
| What does the RLN supply?
Complete:
Complete bilateral RLN injury results in the vocal cords being in a paramedian position causing aphonia and aspiration risk (both abduction and adduction affected)
Partial:
Thus, partial bilateral recurrent laryngeal nerve injury results in complete obstruction (abductors affected most, unopposed adduction of vocal cords) and is an airway emergency.
The RLN provides the only abductors of the vocal cords which are very sensitive to injury/compression
85
Central retinal artery occlusion. Is it painful?
Usually painless.
86
Most common significant complication following retrobulbar blockade?
Explain oculocardiac reflex-are there long term sequelae?
Central retinal artery occlusion leads to:
Puncture of globe leads to:
Retrobulbar hemorrhage is the most common significant complication following retrobulbar blockade leading to an increase in intraocular pressure and vision loss. The oculocardiac reflex stimulation (more common than retrobulbar hemorrhage) may lead to bradycardia and heart block but rarely has significant long-term sequelae. Central retinal artery occlusion leads to painless vision loss, while puncture of the posterior globe leads to painful vision loss without an increase in intraocular pressure.C
87
Obturator nerve originates from:
| Would you ever need to additionally block the nerve?
L2-L4
Transurethral surgery of the bladder usually can be performed with spinal anesthesia without further consideration. If the tumor is along the lateral aspect of the bladder then the obturator nerve may be stimulated and the jerk reflex initiated even under spinal anesthesia. An obturator nerve block should be performed to help prevent this. Alternatively, general anesthesia with muscle relaxation can also be performed to prevent the reflex. If neuromuscular blocking agents are not used during general anesthesia, the obturator nerve block will still need to be performed.
88
The muscle affected is the only vocal cord tensor and the patient is told that his speech will remain changed. Which of the nerves was most likely damaged in this patient?
The only vocal cord tensor is the cricothyroid muscle which is innervated by the external branch of the superior laryngeal nerve
89
Features of a subdural block:
| Is it something about the patient?
Several features - variable motor blockade, excessive sensory blockade, and sympatholysis out of proportion to anesthetic dose given, ‘classically’ define subdural block
Slow onset of blockade, restricted or unilateral distribution of the blockade, severe pain with injection, and even lack of cardiovascular depression can also be seen.Patients that have experienced a subdural block in the past appear to have a higher incidence of it reoccurring, and these patients may prove to be more difficult for neuraxial placement.
90
Before considering giving naloxone in a patient who is not super awake, consider:
When they last got opioids, and their pupil size.
91
What is tension pneumocephalus, what can be an offending agent?
Nitrous oxide should be avoided in patients with recent craniotomy procedures (generally 2-3 weeks). Nitrous oxide may result in expansion of pneumocephalus and result in tension pneumocephalus. Initial treatment supportive and includes high flow oxygen.Tension pneumocephalus may present as delayed awakening or altered level of consciousness, generalized convulsions, seizures, hypertension with resultant bradycardia, severe restlessness, or change in motor exam. Definitive treatment is aspiration of the air loculi by a neurosurgeon.
92
Oculocardiac reflex -explain it,and how do you treat it?
The afferent limb of the oculocardiac reflex is via the trigeminal nerve (cranial nerve V), primarily via the ophthalmic division (V1). The efferent limb is via the vagus nerve (cranial nerve X), which then synapses on the sinoatrial node of the heart.
During ophthalmic surgery, the first line of treatment for bradycardia is to discontinue manipulation of the eye until the heart rate returns to baseline. Prophylactic antimuscarinics (e.g. atropine, glycopyrrolate) are not typically beneficial for adult patients.
93
Sensation in lateral forearm innerated by:
musculocutaneous
