Exam 2023.2 Flashcards
What’s ANZCA’s position on long acting opioid for acute pain?
Best avoided, unless there is a demonstrated need, close monitoring available, and a cessation plan in place
Define opioid stewardship
Coordinated interventions designed to improve, monitor, and evaluate the use of opioids.
What are the most important opioid related harm, ?
OIVI, persistent post discharge opioid use, opioid misuse and diversion
What are the three mechanisms of OIVI
Depression of central respiratory drive
Depression of consciousness
Depression supraglottic airway muscle tone
Downsides of long acting opioids?
increased risk of IVI
Higher risk of persistent post discharge opioid use
Inability to rapidly tritrate dosage
do not lead to better pain relief compared to short acting
Describe some patient selection criteria for day case hip surgery
Independently mobile
BMI < 35
Age <75
ASA 1 or 2
No signfiicant comorbidities or opioid use
General optimisation points for ERAS patients
Ensure proper nutrition and hydration
Optimise haemoglobin levels >100
Minimise fasting times
Key points on program design of ERAS pathway
Standardised anaesthesia protocols
Multidisciplinary team approach (surgeon, nurses, allied health)
Regular audit and feedback to ensure compliance and continuous improvement
Key points on ERAS pre-op stage
Patient assessment - selection criteria
Optimisation
Education - information about procedure, recovery process, set realistic exceptions on pain management
Define life-threatening haemorrhage
Blood loss of ~30-40% of total blood volume
Requires immediate resuscitation and surgical haemostasis to prevent hypovolaemia shock and end organ failure
Pelvic bleeding - why is it signfiicant?
Extensive vascular network, multiple sources of bleeding
Large potential space to accommodate large volume
Associated high-energy traumatic injuries - other sites?
Major haemorrhage -> consumptive coagulopathy
Options to control pelvic bleeding
Pelvic binder - approximate the fracture ends, reduce haemorrhage, stabilise pelvis
Surgical stabilisation - ex-fix , pelvic packing
Radiological embolisation
When could PiCCO be inaccurate?
Intracardiac shunt
Severe AS
Large PE
IABP
Severe arrhythmia
What’s the Stewart Hamilton Equation
Formula used to calculate cardiac output using indicator dilution method.
Generates graph of time vs. indicator concentration.
Area under curve then used to derive CO
In a PAC, what’s the size of the balloon?
1.5ml
In a PAC, what does the thermal filament do?
Allows continuous thermodilution
When PAC balloon is in RA, various waveforms are generated. What do these correlate to ?
a -
c -
x descend
v -
y descend
a - atrial contraction
c - triscupid valve elevation into RA
x - RV contraction, downward movement of RV
v - back pressure from blood filling the RA
y - triscupid valve opening
What are the 3 main West Zones
Zone 1 - dead space, alveolar pressure exceeds PA pressure, no blood flow
Zone 2 - Pa > PA > Pv , intermittent blood flow as alveolar pressure acts as a Starling resistor
Zone 3 - Pa > Pv > PA, continuous blood flow
What’s the effect of respiration on PCWP
Spontaneous breathing
- PCWP reduces on inspiration, increases on expiration
In IPPV
- PCWP increases on inspiration, reduces on expiration
How does thermodilutional method calculate the CO?
Cold bolus of saline / dextrose injected into RA
Users modified Stewart-Hamilton equation
Rate of blood flow (CO) is inversely related to the change in temperature over time.
Faster the blood flow, quicker the neutralisation of temperature
Use of naturetic peptide in preop evaluation
Valuable tool, cheap, readily available.
High negative predictive value, good predictor of death and non-fatal myocardial infarction at 30-180 days post surgery.
Optimal threshold for risk stratification not yet established.
What are the foundational therapies for heart failure
For NYHA II and above, use
- ACE inhibitor, ARBS
- Beta blockers
- Mineralcorticoid receptor antagonists
What are the advanced therapies for heart failure?
For patients with persistent symptoms despite foundation therapy
- Entresto (Neprilysin inhibitor-angiotensin receptor)
- SGLT-2 inhibitor
What are the non-pharmacological therapies for heart failure
Regular moderate-intensity exercise, sodium restriction, fluid restriction, daily weight, smoking cessation
Cardiac rehab.
What are the surgical interventions available for heart failure
Cardiac resynchronisation therapy
LV assist devices
ECG findings of PE
S1Q3T3
Sinus tachycardia
R heart strain
- Right axis deviation
- Complete or incomplete RBBB
- ST depression or TWI in RV leads (V1-4)
What is NELA?
Risk prediction model for 30 days mortality specifically for emergency laparotomy
What are some of the circumstances that warrant VP shunt revisions
Shunt malfunction - 80% of cases within first year after shunt placement
Infection
CSF buildup - hydrocephalus
Growth related displacement
Risks of supernormal oxygen levels
Absorption atelectasis
Airway fire
Not for neonates
O2 toxicity in hyperbaric setting
Delayed recognition of respiratory complication
Benefits of meta-analysis
Increased statistical power - improving the ability to detect true effect
Improved precision
Resolution of conflicting results - resolve uncertainties when individual studies disagree
Generalisability
Identification of research gaps
Limitations of meta-analysis
Heterogeneity
Quality of included studies
Publication biases
Complex statistical techniques
Medical therapies of thyrotoxicosis
beta blocker
PTU
carbimazole
Prevention of thyroid storm perioperatively
Availability of BB
Minimise triggers - stress, pain, infection
High dose steroids
What’s primary vs. secondary post-tonsillectomy bleed?
Primary - within 24 hours
Secondary - after 24 hours, usually 6-10 days
What are the complications of hysteroscopy
TURP like syndrome
Uterine perforation
Cervical shock
Lithotomy - neuropraxia
Cerebral oedema from steep head down
Pre-op measures to improve outcomes in patients undergoing emergency laparotomy
Minimal delay to operation, rapid resuscitation and optimisation of physiological status
Use of validated score, like NELA, to calculate 30 days mortality and need for iCU admission post-op
Intra-op measures to improve outcomes in patients undergoing emergency laparotomy
Use of neuraxial
PONV prophylaxis
Active warming
Goal directed fluid therapy
Restricted use of intra-abdominal drains
Why should abdominal drains use be restricted
Does not improve outcome in colorectal surgery, no early detection of complications. Potential drain associated complications.
Post-op measures to improve outcomes in patients undergoing emergency laparotomy
early removal of lines and drains
Early mobilisation
Early resume of diet
Thromboprophylaxis
Regular assessment of nutritional status
Sensory supply of the hip joint
Capsule divided into
- Anterior supply: femoral, obturator, accessory obturator
- Posterior supply: sacral plexus nerves like superior gluteal and musculoskeletal articulares
What does PENG stand for?
pericapsular nerve group block
How is a PENG block done?
US guided, probe in transverse direction near inguinal canal.
Identify
- anterior inferior iliac spine
- iliopubic eminence
- superior pubic ramus
- Iliopsoas tendon
- Avoid vascular structures / femoral nerve
Injection between superior pubic ramus and iliacus just under the iliopsoas tendon.
How much local for PENG block
10-20ml
Drugs to treat thyrotoxicosis ?
Propylthiouracil 200-400mg TDS
Propranolol 0.1-0.15mg/kg IV
Hydrocortisone 100mg TDS, or dex 2mg QID - blocks T4 to T3 conversion.
Difference between hyperthyroidism and thyrotoxicosis?
Thyrotoxicosis - excessive levels of T3 and T4 resulting in a hyper metabolic state
Hyperthyroidism - biochemical diagnosis of overactive thyroid hormone.
Consideration of emergency thyroidectomy post failed medical management of thyrotoxicosis
initial or continue anti-thyroid treatments
Anticipate and prevention of thyroid storm
Airway assessment for potential mechanical compression
Smooth emergence
Anticipate post-thyroidectomy complications
- Haematoma
- Thyroid storm (rare post)
- Hypoglycaemia
- Replacement of thyroid hormone
