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
(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.
