NROS Flashcards
NEURO - ICP
Decrease ICP measures
[21B05] Justify your strategies for managing severely elevated ICP.
- Avoid CBF
- normocapnia - IPPV
(30-35mmhg)
- normoxia - good O2
- normal BP - analgesia
- warm - Avoid venous pressure
- no cough/strain
- no head down
- no ETT ties - Prevent cerebral oedema
- maintain IV volume and CPP
- CPP>65
- mannitol 20% 1mg/ml
(0.25g/kg)
- NS 5% 100ml
- steroids for tumor and abscess ONLY - DO NOT GIVE for head injury - CSF
- ventricular/lumbar drain - CVP
- head up 30 deg - MAP
- pressor
**OHA **
ER
MKD
brain (1400g)
blood (75mL)
CSF (150mL) (half hald cranium/spinal canal)
BRAIN
- steroids (BUT NOT IN TBI)
- DECRA - tier 3 refrac
BLOOD
1. CPP
a) BP
b) CO2
c) O2
- venous drainage
a) head up
b) loose tie
c) relax - Osmotic
a) Mannitol 10% (1g/kg)
b) NS 3% 3mL/kg
CSF
1. Acetazol
2. EVD to drain CSF (ICP 22 is threshold to rx)
(86.5%) There was an excellent pass rate for this question where candidates were required to justify their management strategies, relating them to the three determinants of intracranial pressure - namely the volumes of the intracranial contents:
brain,
blood, and
cerebrospinal fluid.
Answers that fell short of the pass mark and answers that might otherwise have attracted higher marks were those
failing to demonstrate good understanding of Munro-Kelly doctrine,
those lacking justification of strategies used, and
those containing irrelevant information not directly related to the question.
VP Shunt
Indication:
1. Hydrocephalus
Options:
1. Ventriculoartial
2. Ventriculopleural
Surgical:
1. Occipital burr hole –> LV
2. Tunnel SC down to nec and trunk
3. Peritonal cavity via abdo cut
System:
1. Flushing device - keep system clear
2. Valve - prevent CSF draining too quickly
PRE:
1. assume raised ICP
2. paeds consideration
3. emerg = RSI
PERI:
M: routine +/- IAL
A:
D: IV or IT abx; trocar stimulating - relax/analgesia
E: FAW
POST:
D - ALOC –> CT excl. shunt mal or SDH
Considerations x3
- ICH risk if drained too quick
- shunt - block/infection = resite
- trocar - risk of PTX
oxford
WFNS
SAH Grading / Prognostication!
Severity of SAH
GCS and
motor deficit
–> If Motor deficit, grade 3+
GCS
15 = 1
13-14 no def = 2
13-14 def = 3
7-12 (def/no def) = 4
3-6 (def/no def) = 5
secure aneurysm < 48 hrs post ictus if WFNS1-3 via coil / clip
https://radiopaedia.org/articles/wfns-grading-system
mFS
Radiological
Grading
SAH 2o IC aneurysm rupture
First NC CT
Risk of vasospasm!
V(F)isher
SAH
IVH
spasm%
0 = none = 0%
1 = thin/ none = 24%
2 = thin/yes = 33%
3 = thick/no = 33%
4 = thick/yes = 40%
https://radiopaedia.org/articles/wfns-grading-system
Intracranial aneurysms
Location - junction
Common
1. ACA/AComm 40%
2. MCA bifur 34%
3. distal ICA PCA 20%
RF
1. HTN
2. Smoke
3. FHx
4. PCKD
5. Cocaine
6. CTD
VAE
sx:
1. dec EtCO2!
- inc dead space
2. bronchoconstriction
3. hypoxia
4. arrhythmias
5. MI
6. hypotension
7. cardiac arrest
NEURO - prone.
[21B06] Discuss the perioperative strategies you would use to mitigate the risks of prolonged surgery in the prone position.
Prolonged sx
1. prolong emergence
2. Pressure injury risk
3. Exacerbation PMHx (hypogly)
4. VTE risk
Prone x 5
1. Visual loss
2. PND - ulnar/lfcn
3. soft tissue damage
4. joint
5. Altered CVS/resp
6. IAP
7. Limb compartment
Strategies
PREOP
- consent
- optimise
- pre-existing
INTRAOP
- ETT SECURE
- IDC
- pad
- position
- euvolaemia
- move joint q1-2h
- leak test prior ext
- VAE
- cardiac arrest - pads
POST OP
- neuropraxia ax
- lesions - PT, pain mx, repair
(55.6%) Prolonged surgery in the prone position presents many challenges for the theatre team and risks for the patient.
Candidates were expected to include the following issues in their answer:
- prolonged surgery itself is associated with increased morbidity
- the altered CVS and RS physiology in the prone position
- the risk of peripheral nerve damage
- the risk of postoperative visual loss
As well as discussing intraoperative strategies to reduce risk the role of preoperative risk assessment and postoperative follow up required discussion.
Answers that failed to demonstrate understanding of the above issues or failed to include the preoperative and postoperative components of their perioperative strategies didn’t attract sufficient marks to pass the question.
How do you manage acute life threatening intra operative haemorrhage during a neurosurgical procedures?
SS_NS 1.28
- Reverse heparin
- 1mg protamine for 100 U heparin - BP lowered to pre-bleed level
NEURO – Trans-sphenoidal pituitary surgery / diabetes insipidus
[23A04] Discuss the perioperative management of a previously well patient presenting for transsphenoidal resection of a non-secretory pituitary macroadenoma. Pass Rate 25.6%
[18B06] A patient scheduled for trans-sphenoidal pituitary surgery is noticed to have greater than normal urine output.
a) How would you determine if this patient has diabetes insipidus? (30%)
b) How would you manage diabetes insipidus in the perioperative period? (70%) (also 04B07, 00A14)
PR 25.6%
Pit sx
1. Mass effect
2. Neurohumoral effects of HYPOpituitarism
3. Surgical issues/complications
INTRAOP
- Moffett’s solution - TACHYARRHYTHMIAS and MI
STIM x 2 - nasal access + Moffet’s sol
CPP vs bloodless field
DI diabetes insipidus
low ADH –> dilute urine + concentrate serum (high Na/osm) + dehydration
Hx
- polyuria/polydipsia
Dx
> 250mL dilute urine for > 4 hours
Mx
CENTRAL - desmopression 1-2microg
NEPHRO - HCT/amiloride
Advanced Training in Anaesthesia: The Essential Curriculum (OHST) by Jeremy Prout; Tanya Jones; Daniel Martin [eds]
======================
Pass Rate 25.6%
This question was poorly answered, with many candidates unable to demonstrate key considerations for this condition.
Preoperative consideration of potential mass effects of the adenoma on nearby structures and assessment of endocrine insufficiencies related to hypopituitarism were frequent critical omissions.
Intraoperative discussions often included vague and imprecise cardiovascular goals such as “tight pressure control” without further explanation, or knowledge demonstration of the need to anticipate haemodynamic changes such as occurs with intranasal vasoconstrictor administration or with stimulation during nasal access. Better answers discussed balancing cerebral perfusion pressures and a degree of hypotension to achieve a bloodless field and set targets for this.
Postoperative management required a description of an extubation strategy, which often consisted of only vague statements such as “aim for smooth extubation” without further discussion, or was omitted entirely. There was also frequent lack of any reference to diabetes insipidus and monitoring for this condition, and or it was confused with
=======================
(75.9%) This question was answered well. Better candidates had a structured approach to their assessment and management and recognised hyponatremia as potentially serious. The amount, type and speed of fluid replacement and role of desmopressin was important to mention.
NEURO – Large intracranial tumour
[17B04] A 44-year-old male is booked for debulking of a large intracranial tumour.
a) Describe the physiological aims during this case. (50%)
b) Justify your anaesthetic technique to achieve these aims. (50%) (also 04A05)
Table - 2 columns
- Optimise sx condition
- Prevent 2 brain injury
- Mx ICP
- 4manage haemorrhage
(63.2%) To pass, candidates needed to demonstrate an understanding of the importance of control of ICP and haemodynamics.
Mention of techniques at important time points during the case such as
intubation,
pin insertion and
extubation
was also needed.
NEURO – Innervation for scalp
[16B06] You are asked to provide local anaesthesia for awake craniotomy.
Describe the innervation of the scalp, including the landmarks for nerve blockade.
GGLASSZ
G/L occiptal
G auricular
Auric / Temporal V3
Zygo / temp V2
Supratrochlear V1
Supraorbital V1
NEURO – Primary / secondary brain injury post TBI
[16A07] Outline the pathophysiological insults that exacerbate a primary brain injury post head trauma & indicate how can they be minimised. (also 09B15, 06B08)
Dec 2o brain injury
1. ICP 2. CPP 3. RF
- Monitor
a. Standard + IAL + ICP + EEG +/- CVP - BP
a. sBP > 90
b. CPP > 60 (60-70) - O2 > 60mmHg
- ICP mx
a. ICP < 20 - Seizure proph
- pheny/val/leve - Temp
- normothermia - Glycaemic control
BSL 5-10
conventional no diff in outcome vs tight control - ## Electrolytes
NEURO – Intracranial pressure
[14B02] A 25 year old man with a history of blunt trauma to the right side of his head has a fixed and dilated right pupil.
He has been intubated and ventilated in the emergency department after an initial Glasgow Coma Score (GCS) of 15 on admission had fallen to 3.
Evaluate the pharmacological and non-pharmacological methods to manipulate this patient’s intracranial pressure?
MKD
CPP = MAP - ICP
ICP = 5-15
Pharm
1. Mannitol: 10% 1g/kg
2. NS 3%: 3-6mL/kg
TBI
BTF 2016 GL
DECRA
Osmotx
CSF drain
Vent
Sed
Steroid
Nutrition
Abx
DVT
Seizures
ICP mon*
CPP mon*
sBP target*
DECRA: early/late REFRAC ICP eleveation
Osmo: Mannitol (herniating pts)
CSF drain: continuous; GCS < 6
Vent: avoid HYPERvent (not < 25)
Sed: PPF; barbituate for refractory
Steroids: Level 1 and it is BAD
Nutrition: hit goals by 5-7/7
Abx: prevent VAP, not prophylais
DVT: Stable TBI = TEDS + hep/clex
Seizures: 7/7 pheny
ICP mon - if
1. 22 mmHg threshold for rx
2. GCS 3-8 + abn CT
3. GCS 3-8 + normal CT + age >40 / motor posture / sBP < 90 (2/3)
CPP: 60-70 mmHg
sBP:
100 for 50-69,
110 for 18+ and rest
https://derangedphysiology.com/main/required-reading/trauma-intensive-care/Chapter-101/summary-brain-trauma-foundation-guidelines
NEURO – Induction for combative patient with TBI (urgent crani / decom)
[11B06] A 50-year-old patient presents for urgent craniotomy and decompression of a subdural haematoma. Two days ago he was well, but now has a Glasgow Coma Scale score of 11. He is combative and has pulled out his intravenous line. On inspection there are no obvious veins for cannulation.
a) List the options available for induction and intubation. (30%)
b) Describe and justify your preferred approach. (70%)
Issues
1. Det GCS = need AW + surg
2. Agitated from ?worse ICP
3. No IV access
Priorities
1. CONTROL
2. Induce and intubate
a) prev ICP
b) prev hypotension
c) min aspiration
(59%) Key components of a response to this question included:
- Identifying the options for induction and intubation given the problem list in the clinical situation described:
o deteriorating GCS
o associated rising ICP
o requirement for intubation in this emergency setting o absent intravenous access - Describing and justifying a preferred approach given the problem list.
NEURO – Posterior fossa surgery / venous air embolism
[11A07] A patient is scheduled for posterior fossa surgery in the sitting position.
a) Outline the precautions you would take to minimise the risk of venous air embolism.
b) How would you recognise an air embolism intraoperatively?
c) How would you manage an air embolism causing haemodynamic compromise intraoperatively?
Pos Fos =
1. BS
2. cerebellum
3. CN 4-12
60% paeds brain tumor in POS FOS
Consideration x6
1. Indication - seizures, ICP
2. Position - lateral, prone
3. Mods for neuromon - TIVA, no para
4. Brain relax - TIVA, mannitol,
5. Compli - haemorrhage, VAE
6. Limited access - foresight
VAE - pressure within OPEN vessel is SUBATMOS
- 20cm + above heart
- sitting worse
- LSCS / crani / spinal
Precaution
VAE Mx
- declare EMERG
- HELP
- ABC
** Prevent further AE **
- operative site below RA
- IV fluids
If RVOTO
1. Head down
2. L lat (Durants maneouvre)
3. Asp air for CVC
NEURO – SAH / coiling
[22A07]
Discuss the anaesthetic considerations for a patient requiring cerebral aneurysm coiling.
[10A07] A 43 year old female w/ a Grade 1 subarachnoid haemorrhage is scheduled for coiling of her MCA in the radiology suite. Discuss the important issues to consider when providing anaesthesia for this patient.
PR 13.6%
Clipping = crainotomy
Coiling = endovascular / IR
+
** RRP = remote, radiation, prolonged **
Grade - WFNS
- guides Rx
Grade 1-3 - secure aneurysm
Grade 1 - GCS 15 - good prognosis
Complications
1. Rebleed
- 5-10% -
- highest 1st 24h
- Vasospasm
- **peak 4-10d **
- Rx = NIMODIPINE
60mg PO/NG q4h
but HYPOTENSION!
Classic = 3H
Hypertension
Hypervolaemia –> now euvol
Haemodilution
- Pre
elec vs urgent
Urgent - likely compl of SAH –>
- mod RF - fever/seizure/hypergly/anaemia/sepsis
- SAH compl = 1. SIADH/ECG/coag
- vasospasm prophy
- REMOTE
1) location
2) staff/equip PS55
3) post op care - consent
- Intra
- PIVC + IAL
- IDC
+ contrast nephropathy
+ radiation safety
COMPLICATION
- haemorrhage
- coil displ
- vasospasm
- anaphylaxis
- Post
- controlled emergence
- LMA exchange
- bleeding from access site
- monitor for DCI (vasospasm 4-10 days)
- PACU - reduce GCS –> r/o hydrocephalus / vasc compl
OHA P.580
Pass Rate 13.6%
The minimum standard to pass this question considered
acute and elective procedures and the differences in their presenting pathophysiology and
**required a correct discussion of intraprocedural management of haemodynamic goals. **
A mention of the
potential for rupture of the aneurysm, as well as
appropriate postoperative disposition and monitoring were also required.
More peripheral issues (e.g. remote anaesthesia, radiation, prolonged procedure) were often considered well, but at the cost of discussion of the core required issues.
SS_IC 1.83
(62.7%) Key components:
- The relevance of the grade of subarachnoid haemorrhage with respect to prognosis
- An understanding of the risk of rebleeding + cerebral vasospasm and how to prevent them,
including comment on use of nimodipine - An awareness of complications such as ECG or electrolyte changes
- An understanding of the principles of management of any neurovascular procedure
(normotension, normothermia, normoglycaemia etc) and how to achieve this (eg
propofol/remifentanil by infusion) - A description of appropriate monitoring (eg art line, temperature, neuromuscular monitoring etc)
- A description of issues re the site (difficulties of working in remote location, poor lighting, difficult
access to the patient), or the vascular access (damage to, or bleeding from, the femoral artery). - A postoperative plan
NROS - clipping
Clipping vs coiling
Clipping = crainotomy
Coiling = endovascular / IR
NROS - clot retrieval
[22B03]
Discuss the perioperative management of a patient requiring clot retrieval for an acute ischaemic stroke.
PR 33%
Time critical
GA vs LA + sedation
GA
pros:
- better operating conditions
- definitive airway
- control CO2
cons
1.
LA + sedation
- better HD
- avoid GA
cons:
- long procedure
- pt movement
sBP target
140-180 if lysed
140-220 if not
- vasopressors
Hypotension - reduce BF to penumbra –> worsen infarct
Hypertension - haemorrhage
Post op
bupa
OHA P.582 Endovascular thrombectomy
Pass rate 33.3%
This question was poorly answered, and it is possible that it reflects lack of experience in this area of anaesthesia practice.
Given there is significant demand on anaesthetic departments to provide support for patients undergoing a variety of interventional procedures it is expected that candidates will be familiar with the issues involved in caring for these patients.
Candidates were required to demonstrate an understanding of:
- the time critical nature – minimising time from presentation to the intervention
- the importance of maintaining adequate cerebral perfusion - high targets for bp pre- and during the
procedure - the** advantages/disadvantages of anaesthesia techniques** – GA or LA +/- sedation
- the requirement for post procedure high acuity monitoring of bp and neurological status.
Candidates’ reliance on the proceduralist for advice or instruction was commonly seen in answers and whilst this procedure is undoubtedly a collaborative one a discussion of the *principles behind the haemodynamic goals was required.
Whilst all candidates described pursuing a GA technique in this scenario few identified the pitfalls of this technique as opposed to LA +/- sedation/monitored care.
Many candidates also tended to devote a large proportion of their answer to potential difficult airway management in a remote site and whilst it is an ‘off-floor’ procedure this was not the primary consideration here.
