Random/Misc Flashcards
Define SPECIFICITY
The ability of a test to correctly identify those patients WITHOUT the disease
What is the mathematical equation for SPECIFICITY?
Specificity = True Negatives/True Negatives + False positives
Define SENSITIVITY
The ability of a test to correctly identify patients WITH the disease
What is the mathematical equation for SENSITIVITY?
Sensitivity = True Positives/True Positives + False Negatives
What is a meta-analysis?
A statistical discipline of assimilating data from multiple similar smaller studies
To measure an overall effect using all the available evidence
A quantitative form of systematic review
What is a Forest plot?
Graphical means of comparing studies included in a meta analysis
Square = each study (size represents study size) is a square; the line is the 95% confidence interval Diamond = pooled data from all studies; width represents 95% CI
List the 5 levels of evidence
1a. Systematic review of multiple RCTs - meta-analysis; 1b. RCTs
2. Cohort study
3. Case-control study
4. Case series
5. Case report; expert opinion
How do you measure the osmolar gap?
Measured osmolality - calculated osmolality
Calculate osmolality = ((1.86 x Na+) + urea + glucose + ethanol)/0.93
Normal range = -9 - +19
How do you measure the anion gap?
(Na + K) - (HCO + Cl)
Normal range 12-16
Describe the 2 types of AAGA
Explicit awareness: conscious recollection of events either spontaneously or on direct questioning
Implicit awareness: implicit memories exist without conscious recall, but can alter behaviour after event
List some risk factors for having AAGA
Neuromuscular blockade use C section (highest risk - 1:670) RSI Thiopentone use TIVA Female patients Out of hours operating Junior anaesthetist Previous AAGA
How would you manage someone with AAGA?
Involve senior See patient with nurse/midwife Establish exact nature of AAGA - pain; implicit vs explicit Apologise/empathise with patient Explain nature of anaesthetic and how AAGA happens Invite questions Offer follow up Document carefully Inform GP Incident report
What options are there for depth of anaesthesia monitoring?
EEG based - BIS/pure EEG/M-Entropy Clinical signs/observations Evoked potentials - auditory/motor/sensory Isolated forearm technique Frontalis EMG Lower oesophageal contractility
What is the EEG wave pattern consistent with: wakefulness?
Fine wave/beta-wave activity
What is the EEG wave pattern consistent with: surgical anaesthesia?
Spindle waves
Alpha waves
Theta waves
Delta waves
What is the EEG wave pattern consistent with: excessive anaesthesia?
Burst suppression
What are the levels of cleaning of medical equipment?
Decontamination - removal of contaminants before disinfection/sterilisation; done by washing or scrubbing
Disinfection: killing of non-sporting organisms
Pasteurisation - hot water at 77 degrees for 30 mins; intermediate level disinfection
Chemical - alcohol/aldehydes
Sterilisation: killing of all micro-organisms Dry heat Moist heat (autoclave) Ethylene oxide Gamma irradiation
Describe some types of bias
Attrition bias - failing to account for withdrawals
Publication bias - positive results
Language bias - English
Inference/reporting bias - authors place more weight on positive findings and ‘explain away’ negative findings
Selection bias - poor patient randomisation; avoided using blinded randomisation
Allocation bias - self-selecting well motivated people
Measurement/performance bias - people feel better or try more things, knowing they’re being measured
Detection bias - if researchers know which group they are checking; avoided by blinding
Commercial bias - influenced by funding body
What factors must be taken into account for consent to be ‘informed’?
Patient must have capacity
Able to receive and understand information
Free from coercion
Information is rational
Mentioning significant hazards
Can withdraw consent at any time (if still has capacity)
Name 2 acts of parliament which legislate for capacity to consent in the UK
Mental Health Act of 1985
Mental Capacity Act 2005
What is a Caldecott Guardian?
Person responsible for protecting the confidentiality of patient records
Ensures information is governed properly
What is the Hagen Pouiseille equation?
Pi x dP x r4
——————
8nl
Pi x delta P x r to the power 4
Divided by
8 x viscosity x length of tube
What is Reynold’s number?
The number at which flow changes from laminar to turbulent flow
d x v x p
—————
n
Diameter x velocity x density of liquid
n = viscosity
What supplies motor innervation to the larynx?
Recurrent laryngeal nerve
-all intrinsic muscles except cricothyroid
External branch of SUPERIOR laryngeal nerve:
-cricothyroid
What is the sensory intervention to the larynx?
INTERNAL branch of SUPERIOR laryngeal nerve
- inferior surface of epiglottis
- superior surface of larynx down to cords
Recurrent laryngeal nerve
-below cords
What are the features of LASER?
Monochromatic
Non-divergent (collimated)
In phase (coherent)
Describe ANOVA
Analysis of Variance
A test that compares 3 or more normally distributed groups of interval data
Describe un-paired Student’s t-test
A test to compare two normally distributed independent groups
Describe paired Student’s t-test
A test to compare two normally distributed matched groups
Describe Wilcoxon rank sum test
A test that compares the mean of one sample group against a known value
A test for non-normally distributed data or a one sample t-test for normally distributed data
Describe the chi-squared test
A test that compares greater than three sample proportions of categorical data
Regarding the description of a skewed dataset, the most commonly quoted measure of data spread is…?
Interquartile range