General Flashcards
What is the declaration of Helsinki?
- Volunteers
- Informed consent
- Wellbeing of individuals overrides population
- Research only if likely to benefit population
What are the 4 pillars of medical ethics?
1) beneficence 2) non-maleficence 3) equipoise 4) justice
Give an example of a good communication type in pre-hospital care
Hand’s off Handover
Which risk factors are on Koivuranta’s PONV score
female gender, non-smoking status, history of PONV, history of motion sickness, and duration of surgery >60 min
Describe the scoring of Koivuranta’s PONV score
0 = 17% (baseline) 1 = 18% 2 = 42% 3 = 54% 4 = 74% 5 = 87% ROC = 0.71
Describe the Apfel simplified score
PONV scoring system: female gender, history of PONV or motion sickness, non-smoking status, and postoperative use of opioids
How does the Apfel PONV score relate to PONV risk?
0 = 10% 1 = 20% 2 = 40% 3 = 60% 4 = 80%
What is the POVOC score?
Scoring system for PONV in children
What are the risk factors in the POVOC score?
duration of surgery ≥30 min, age ≥3 yr, strabismus surgery, and history of POV in the child or relatives
Provide 3 scoring systems for PONV
Koivuranta - Adult Apfel - Adult POVOC - Children
Define perioperative high risk
> 5% perioperative mortality
Why is establishing risk so important?
High risk patients account for 12.5% of cases but 80% of perioperative mortality
What were the main NCEPOD (2011) findings for “high risk” patients
- “High risk” was arbitarily defined by anaesthetist
- 20% were identified
- 6.2% 30-day mortality
- 1/4 had art lines
- 5% had cardiac output monitoring
- 22% went to HDU/ITU immediately postop
- 50% who died never went to ITU
Identification methods for “High-Risk Patients”
- Clinical judgement
- ASA
- P-POSSUM
- Euroscore (cardiac)
- Surgery Type
- CPEX
List high risk surgical operations
- Open aortic
- Major vascular
- Peripheral vascular
- Urgent body cavity
List the highest risk perioperative co-morbidities. Give % 30 day mortality
- Documented cirrhosis (8.9%)
- CCF (8.2%)
- Arrhythmia (5.7%)
- CVA (4.4%)
- Diabetes (on insulin) (4.1%)
- Ischaemic heart disease (3.8%)
- Cancer (3.8%)
What is the perioperative role of echo?
- Resting - information made no difference in 1 year outcomes (40,000 patient retrospective review)
- Dynamic - identifying inducible ischaemia improved outcomes
What is the role of perioperative CT angiography?
- Can identify those with CAD
- Indications for treatment remain the same as for non-surgical patients
How should you care for high risk patients?
- Optimise medical co-morbidities
- Plan appropriate:
- Monitoring
- Fluid management
- Analgesia
- Decide on appropraite post op care
What is CPEX?
An incremental workload stress test. A dynamic test of global cardiorespiratory function
What are the phases of CPEX?
- Baseline recording (3 mins)
- Unloaded cycline (1-3 mins)
- Graded increasing resistance
- Rest (10 mins)
What is pre-habilitation?
- A cardiac rehab like program.
- Increases VO2 max by 20-30%.
- Mitigates impact on VO2 by chemotherapy.
- Unclear if any survival benefit
What are positive CPEX indicators for ward level care post major surgery?
- AT > 11 mL/min/kg
- No myocardial ischaemia
- Ve/VO2 < 35
What are the positive CPEX indicators for HDU care post major surgery?
- AT > 11 mL/kg/min
- Detectible myocardial ischaemia or;
- Ve/VO2 > 35
What are the positive CPEX indicators for ITU care post major surgery?
- Aortic or oesophageal surgery
- AT < 11 mL/min/kg
Why might beta-blockers work to lower perioperative mortality?
- Reduce O2 demand
- Prevent tachycardias
- Negatively ionotropic
- Reduce cardiac events
Guidelines of perioperative beta-blockade
- Continue if already on
- intermediate/high risk for myocardial ischaemia - consider starting peri-op
- > 2 Revised risk factors - consider starting peri-op
- Do not start on day of surgery
- Try to start eariler if going to do so
Duration of antiplatelets following coronary intervention
- DES - dual for 6-12 months
- BMS - dual for 4-6 weeks
- Balloon angioplasty - dual for 2 weeks
Describe bridging therapy for antiplatelet treatment
- Initiated 5 days pre-op at time of stopping clopidogrel
- Tirofiban - stop 3-6 hours pre-op
- Eptifibadine - stop 4-12 hours pre-op
Define Enhanced Recovery
- An evidence based process for non-daycase surgery deisgned to:
- Improve patient outcomes
- Reduce length of stay
- Reduce complications
- Reduce financial burden
- By employing:
- Organisational change and training
- Standardised perioperative care
- Active patient engagement
What are the primary outcomes demonstrated in ERAS?
- Better outcomes
- Reduced LOS
- Increased number of patients treated
- ? Mortality (1 orthopaedic study)
What are the 4 elements of ERAS?
- Pre-op assessment, planning and preparation
- Reducing the physical stress of the operation
- Standardised immediate perioperative management
- Early Mobilisation
What are the benefits of goal directed fluid therapy?
- Reduced LOS for major abdominal, gynae and urological surgery
- Reduced PONV
- Reduced gut hypoperfusion
- Redcued GI complications (ileus, delayed feeding)
What is the FTc?
The duration of flow during systole corrected to a HR of 60. Normal is 330-360ms
Causes of increased FTc?
- Low afterload (i.e. vasodilated)
Causes of decreased FTc?
- Increased afterload
- Peripheral vasocontriction
- Underfilled
What is Peak Velocity?
The highest blood velocity detected during systole, (left ventricular contractility/ionotropy).
What are typical Peak Velocity values?
- 90-120 cm/s (20 year old)
- 70-100 cm/s (50 year old)
- 50-80 cm/s (70 year old)
These are NOT physiological targets
What does a low Peak Velocity suggest?
- Failing left ventricle
- Excessive afterload
What is the general management for peri-operative diabetes?
- Early identification of high risk patients
- Day of surgery admission is default
- Minimise starvation (consider list order)
- Resume normal diet ASAP
- Analgesia/Antiemesis to support early eating
- Use the term “variable rate IV insulin infusion”
- If missing just breakfast, modify patients own meds
- Missing > 1 meal, place on VRIII
- Continue long acting insulin whilst on VRIII
- Hourly BM intra-op/post-op
How to transfer VRIII to usual regimen
- Establish normal eating / drinking
- Restart previous regimen and dose
- After first dose of S/C insulin, stop VRIII 30 mins later
Pre-operative blood conservation techniques
- Anaemia clinics
- FeSO4 tablets / infusions
- EPO
- Stopping antiplatelets
- Disease optimisation
- Micro-sample collection
- Normo-volaemia haemodilution
Intra-operative blood conservation techniques
- Meticulus surgeons
- Warming
- TEG
- Aprotonin
- Tranexamic Acid
- Cell salvage
- off pump surgery
- Platelet mapping
- Tight and dry CPB
Post-operative blood conservation strategies
- Restrictive transfusion thresholds
- Autologus transfusions
- Warming
What did NAP 5 Study?
Accidental Awareness under GA
What were the basic findings of NAP 5?
- 300 cases reviewed (Delay 0 - 62 years)
- 141 Certain/Probable cases of AAGA
- 17 Awake paralysis
- 7 AAGA in ITU
- 32 AAGA after sedation
What is the incidence of AAGA?
- Baseline risk 1:19,000
- 1:136,000 if not using NMB
- High risk groups included:
- 1:8,000 if using NMB
- 1:8,600 Cardiothoracic anaesthesia
- 1:670 Caesarean section
What is the likely long term psychological impact of AAGA?
- 41% experience moderate/severe long term sequelae
- Best predictors of long term harm were:
- Distressed at time of event
- Sensation of awake paralysis
- Understanding of what was happening at the time, reassurance, and early support helped to mitigate this risk
What are the risk factors/recommendations for AAGA at induction?
- Risk factors
- Thiopental
- RSI
- Obesity
- NMB
- Difficult airway management
- Long transfer gap from AR to OR
- Recommendations
- Check list following transfer
What are the causes of/recommendations for AAGA at emergence?
- Nearly all due to residual NMB
- Recommendations
- Ensure NMB monitors used
- Check reversal at end of case
What are the risk factors for AAGA?
- Drug factors
- Thiopental
- TIVA
- NMB
- Patient factors
- Women
- Young adults
- Obesity
- Previous history of AAGA
- Subspecialties
- Obstetric
- Cardiothoraccic
- Neurosurgical
- Organisational factors
- Emergency
- OOH
- Junior anaesthetists
What are the caveats to TIVA in the context of AAGA?
- Less common when using TCI
- Many cases associated with disconnection/failure of delivery
- Transferring from volatile to TIVA particularly high risk
- More comming in transfer of paralysed patients outside theatre
What does NAP 5 have to say about AAGA following sedation?
“Reports of AAGA after
sedation represent a failure of communication
between anaesthetist and patient and should
be readily reduced or eliminated by improved
communication, management of expectations and
consent processes.”
How many recommendations does NAP 5 make?
- 64 in total
- 7 National
- 12 Instituational
- 45 Personal
What did NAP 4 Study?
Major complications of airway management in the UK
How many anaesthetics are given each year in the UK? What is their typical airway management?
- Approx 2.9 million GAs/year
- 56% - supraglottic airway device (SAD)
- 38% - tracheal tube
- 5% - face mask
What were the key findings of NAP 4?
- Failure to assess airway
- Failure to act on airway assessment
- Failure to plan for failure
- Fixation with intubation
- Innapropriate use of SAD
- SAD used in difficult airways with no backup plan
- Obese patient twice as likely to have difficult airway
- High failure of cannula cricothyroidotomy (60%)
- Aspiration was the single commonest cause of death
- Failure to interpret capnography correctly
- 1/3rd of events occurred at extubation/recovery
- 1/4 of all major airway events was from ICU/A&E (significantly over-represented)
What did NAP 3 Study?
Major Complications of Central Neuraxial Block in the United Kingdom
What were the basic findings of NAP3?
- 700,000 CNB
- 46% Spinals vs 41% Epidurals
- 45% Obstetric vs 44% Perioperative
- Permanent injury following CNB
- 1/24,000 - 1/54,000
- Death following CNB
- 1/50,000 - 1/140,000
- Over-represented groups included:
- Epidurals (60%)
- CSEs
- Perioperative analgesia (80%)
- 2/3rd of injury initially judged severe resolved fully.
How is type 2 diabetes diagnosed?
- HbA1C > 48 mmol/L (>6.5%)
- a random venous plasma glucose concentration ≥ 11.1 mmol/l or
- a fasting plasma glucose concentration ≥ 7.0 mmol/l (whole blood ≥ 6.1 mmol/l) or
- two hour plasma glucose concentration ≥ 11.1 mmol/l two hours after 75g anhydrous glucose in an oral glucose tolerance test (OGTT).
What is impaired fasting glucose?
Fasting glucose 6.1 - 7 mmol/L
What are the recommendations from “The measurement of adult blood pressure and management of hypertension before elective surgery” Anaesthesia 2016
- Pre-op assessment doesn’t need to measure BP if primary care has documented < 160/100 mmHg
- GPs should refer for elective surgery, and secondary care should accept, if BP < 160/100
- GPs should refer patients who are established on antihypertensives, but are refractory
- Elective surgery should proceed if BP <180/110 when measured in clinic
Define and categorise Hypertension
Abnormally high blood pressure, categorised as:
- Stage 1: 140-159 / 90-99
- Stage 2: 160-179 / 100-109
- Stage 3: 180-209 / 110-119
- Stage 4: > 210 / > 120
What does 15 mL (1 unit) of cryoprecipitate contain?
- Fibrinogen (150-250 mg)
- Factor VIII (80-150 IU)
- Factor XIII (80-100 IU)
- von Willebrand factor (50-75 IU)
- Fibronectin
What is the parkland formula?
4 ml × weight (kg) × total percentage of burns.
Half the fluid should be given in the first eight hours and the remaining fluid over the next 16 hours.
Describe the physiological role of magnesium
- Na/K ATPase co-factor
- cAMP magnesium dependend
- NMDA receptor antagonist
- Decreases Ach release at NMJ
- Inhibits clotting cascade
- Calcium antagonist
What is the recommended cut off patient dose for peri-operative steroid replacement?
10mg predniolone at any point within the past 3 months
What are the recommendations for steroid replacement?
- Minor surgery
- 25 mg hydrocortisone at induction
- Moderate surgery
- Take normal steroid
- 25 mg hydrocortisone at induction
- 100 mg hydrocortisone over 1 day
- Major surgery
- Take normal steroid
- 25 mg hydrocortisone at induction
- 100 mg hydrocortisone/day for 3 days
Give the equivalencies for 10 mg Prednisolone (include betamethasone, beclomethasone, cortisone acetate, hydrocortisone, methylprednisolone and deflazacort)
- betamethasone = 1.5 mg
- beclomethasone = 1.5 mg
- cortisone acetate = 50 mg
- hydrocortisone = 40 mg
- methylprednisolone = 8 mg
- deflazacort = 12 mg
