Clinical Flashcards
Severity Assessment Mild to Moderate CDI
- WCC < 15 x109/L
* < 5 stools of type 5 to 7 on the Bristol Stool Chart.
Severe CDI is associated with the following
- WCC > 15 x109/L
- An acute rising serum creatinine (i.e. >50% increase above baseline) a temperature of > 38.5°C
- Evidence of severe colitis (abdominal or radiological signs)
- The number of stools is a less reliable indicator of severity.
Life-threatening CDI includes:
- hypotension,
* partial or complete ileus, toxic megacolon or CT evidence of severe disease.
What do you put patient on if suspected CDI (what Is SIGHT)
Vancomycin oral or IV if not tolerated- start empircally
Clinicians should use this mnemonic (SIGHT) when managing CDI:
S- Suspect a case may be infective when there is no other obvious cause for diarrhoea
I- Isolate the patient & consult the Infection control team while determining the cause of diarrhoea
G- Gloves and apron must be used for all contacts with the patient and their environment
H- Hand washing with soap and water should be carried out before and after each contact with patient and their environment
T- Test the stool for C. difficle toxin by sending a specimen immediately to Microbiology.
Other:
· Severity assessment
· Review the need to continue antibiotics for other indications (if any) in conjunction with medical microbiology
· Look for signs of acute abdomen, ileus or toxic megacolon and order abdominal X-ray and refer to surgeons urgently if required.
· Stop contributory agents (i.e. laxatives)
· Stop antimotility agents where possible (i.e. loperamide, opiates)
· Need for fluid resuscitation and electrolyte replacement,
· Nutritional status
· Presence of signs of increasing severity of disease - refer to ITU early as patients may deteriorate very rapidly
Once confirmed
Fidaxomicin oral
If impossible give metrondizaole IV
May do surgical colectomy
Vitamin D metabolism what are the 3 ways that vitamin D gets in
3 ways of getting in vitamin D:
1. Vitamin D is formed from7-dehydro-cholesterol –via UV light> this forms cholecalciferol (vitamin D3)
(NOTE need 20 mins of sunlight)
2. Ergocalciferol (Vitamin D2)is formed from the diet supplementation
3. Via natural sources such as fish can getcholecalciferol (vitamin D3)
- Within the liver- Hydroxylation on C25 occurs–>calcidiol 25-hydroxy vitamin D3
Happens all the time viavitamin D 25 hydroxylase - Within the kidney
Hydroxylation on C1 via1a hydroxylaseoccurs–>1,25 dihydroxy vitamin D3which is active
This is the regulatory step which is controlled via PTH and calcium- this regulates how much vitamin D we need
What is 1mv equal to in mm and small squares on an ECG
10MM WHICH IS 10 SMALL SQUARES
What is the speed of an ecg
25mm/s
What is a large square equal to in mm and secs
5mm and 0.20 sec
What is a small square equal to in mm and secs
1mm which is 0.04s
What is an R wave
R wave is defined as the first POSITIVE deflection of a QRS complex (regardless if it preceded by a downwards peak (Q) or followed by a downwards peak (S)
What is a Q wave
Q wave is defined as the negative deflection before the R wave (i.e it is the first negative deflection of a QRS complex that is not preceded by a positive deflection but is then followed by a positive deflection (i.e an R wave)
What is an S wave
It is the negative deflection after the R wave
How to check the rhythm on an ECG- Regular/irregular/sinus (3 conditions)
Can be regular or irregular
If irregular is it regularly irregular (current pattern of irregularity) or irregularly irregular (completely disorganized)
To do this look at the R-R intevals
Sinus rhythm - cardiac impulse starts in the sinus node
P wave must be +v in I, II, AVF
P wave must be -ve in AVR
QRS must be after P
How to count the rate on an ECG
If its regular: 300/big boxes between R-R or 1500/small boxes
○ If it is irregular: No of QRS complexes x6 in the rhythm strip- As a rhythm stirp is 10 seconds, therefore x6, is rate for 60 seconds
Draw the cardiac axis chart what is the normal adult range
-30 to +90 but this is different from children
What leads do you look at for AXIS
AVF and I
Look at the QRS
What is normal for axis
The QRS should be going up in both leads.- positive
What is right axis deviation?
If leads 1 and AVF are reaching towards eachother i.e down in 1 and up in AVF
suggests RVH
What is left axis deviation- how to test for true
Lead I is positive, lead AVF negative: LA DEVIATION: LEEEEEAVING EACHOTHER
If there is apparent LAD check in lead II
If lead II +ve= normal axis
If lead II-ve= true lad
Suggests LVH
What should you consider with P waves
Amplitude
- Less than 2.5mm tall (<2.5small squares) in the limb leads
- Less than 1.5mm tall (<1.5small squares) in the chest leads
• Duration
- Less than 120ms long (0.12s; <3 small squares) within any lead
Morphology
- Should be upright in leads I, II, AVF and inverted in AVR (i.e sinus)
- Should be bisphasic in V1
Abnormal P Waves: Peaked P waves (P pulmonale) Bifid P wave (P mitrale) Absent P waves Flutter waves Inverted P waves
What is peaked P waves- what does it suggest?
P waves are taller and are pointy (peaked) in appearance.
- Duration unchanged (still <120ms)
Indicates presences of right atrial enlargement/abnormality (aka P pulmonale)
Best seen in lead II
> 2.5 mm tall in lead II (or III/AVF), satisfying criteria of right atrial abnormality (RAA)
> 1.5 mm tall in V1 (or V2), satisfying criteria for right atrial abnormality (RAA)
RAE classically seen with Pulmonary Hypertension
What does bifid P waves suggest
Indicates presences of Left atrial enlargement/abnormality (aka P Mitrale)
Best seen in lead II and V1 – LAA Criteria:
Lead II: Bifid and ≥120ms (Interpeak interval of ≥0.04s)
Lead V1: -Ve deflection of P wave wide (> 0.04 s) and deep (> 1 mm),
LAE classically seen with left sided valvular disease - mitral stenosis but can be benign
What is the PR interval how long is it normally, when it is shortened, when it is prolonged?
Normal value is 0.12-0.2 (3-5 small squares) Can be: Shortened <0.12 s (3 small squares) Normal 0.12-0.2 (3-5 small squares) Prolonged >0.2 s (5 small squares)
What are the 4 things to check on the QRS
QRS - check the width, the amplitude, pathological q waves, R wave progression
What should the width be on the QRS
Width
• Under 0.12 seconds (3 small squares)- narrow complex originates above the ventricles
○ Narrow complex is normal - usually the bundle of his purkinje fibres
• Wide is over 0.12 second (3 small squares)
○ Wide because of a slower speed of ventricular depolarisation due a problem with:
• With HIS purkinje system
• Relying on muscle- muscle spread via gap junctions which is slower
Look at the ones which are entirely positive and negative to look at the width
What should the amplitude be on the QRS
Amplitude
• Mainly used to identify LVH and RVH
• Tall
○ Left ventricular hypertrophy
Criteria: sokolow lyon: look at the S wave in V1 (largest measurement) and the R wave in V5 or V6 (whichever is larger)
If the sum= +33mm (> 7 large squares)= LVH
○ Right ventricular hypotrophy
• Right axis deviation
• Dominant R wave in V1 (>7mm tall or R/S ratio>1)
• Dominant S wave in V5 or V6 (>7mm deep or R/S <1)
• QRS duration <120ms (i.e changes are not due to RBBB)
• Shorter suggests Impedance e.g fat, fluid etc
What are the features of a normal Q wave on the QRS
Remember Q wave is the first negative deflection before the R wave:
• <2mm deep
• <1mm wide (<40ms)
• Absent in V1-V3
What are features of a pathological Q wave on the QRS
• Features ○ >1mm wide (>40msec) ○ >2mm in height ○ >25% of the R wave amplitude ○ Seen in V1-V3 Usually indicate current or prior MI
What is the R wave progression in the QRS?
• As you go from V1-V6 the electrodes are progressively more left on the chest meaning they will get more in line with the major ventricular depolarisation- therefore R wave progression from negative to positive
○ If get early- suggests that it is RVH
• Transition point is between V3/V4, also normal between V2/V3
What is the ST segment?
ST Segment
Should be isoelectric in every lead
If more than 1mm elevated in limb leads (1 small square)
If more than 2mm elevated in chest leads (2 small squares)
Suggests an MI
If more than 1mm depressed= myocardial ischaemia
What is the QT interval?
QT is related to heart rate- therefore need to correcte it
As a general rule if QT is less than half of the RR interval: it is probably normal, usually works for normal heart rates (60-100)
Corrected QT interval: Bazett’s formula= QTC=QT/ square root of RR
Depends on the sex
> 440ms in men
> 460ms in women
What should the T wave be?
• The T wave is a positive deflection after each QRS complex and represents the ventricular repolarization
• Normal: Upright in all leads except AVR and V1
Check +ve in I, II, III, AVL, AVF, V2-V6
• Lots of shapes:
○ T wave inversion- ischemia
○ Peaked T waves- hyperkalaemia
○ Hyperacute T waves
○ Inverted T waves
○ Biphasic
○ Camel hump
Easy way to do BBB
Abnormally wide QRS complexes = > 0.12 s (> 3 small squares width)
- Indicates abnormality in conduction through ventricles à Slow Depolarisation through the Parts of Ventricles.
• An abnormally wide QRS without a tachycardia - Most likely a Bundle branch block (BBB)
Widened QRS without tachycardia is a BBB, Then LOOK AT V1:
• If V1 is mainly positively deflected it is a Right Bundle Branch Block
If V1 is mainly negatively deflected it is a Left Bundle Branch Block
More complex way to find left bundle branch block
Widened QRS without tachycardia is a BBB, Then LOOK AT V1- negative= left bundle branch
WiLLiaM – in LBBB there is a ‘W’ in lead V1 and an ‘M’ wave in lead V6.
• QRS Complex > 120ms
• Dominating S wave (either rS or qs) usually followed by ST elevation and prominent T Wave in V1 (/V2/V3)
• Wide Slurred R Wave in Lead I and V6
• ST-T Wave changes: T wave deflection is opposite direction to the last QRS deflection in all three of V1, V6, lead I
(LBBB usually causes LAD)
OVERALL Look at V1, V6 and Lead 1
More complex way to find right bundle branch block
Widened QRS without tachycardia is a BBB, Then LOOK AT V1- positive= right bundle branch
RBBB there is an ‘M’ wave in lead V1 and a ‘W’ wave in lead
1. QRS Complex > 120ms
2. RSR’ Wave in V1 - aka bunny ears
3. A wide/deep S-wave in V6 and/or Lead I.
4. ST-T Wave changes: T wave deflection is opposite direction to the last QRS deflection in all three of V1, V6, lead I
(RBBB does not usually cause RAD)
Some considerations about BBB
• RBBB is not always abnormal but should be flagged up, e.g. normal in athletes
• LBBB is ALWAYS abnormal. Should be investigated further.
• RBBB Severely inhibits ability to diagnose RVH
LBBB Severely inhibits ability to diagnose LVH and STEMI (As get ST elevation)
What is a bifascicular block?
RBBB with LAD= bifasicular block i.e LAFB + RBBB
RBBB with RAD= bifascicular block i.e LPFB + RBBB
Bifasicular block is conduction abnormality in the heart where two of the three main fascicles of the His/Purkinje system are blocked
What are the Eye’s components of GCS
1: does not open eye
2: opens eye in response to pain
3: opens eye in response to voice
4: opens eyes spontaneously
what are the verbal components of GCS?
1: no sounds
2: incomprehensible sounds
3: inappropriate words
4: confused, disorientated
5: orientated converses normally
What are the motor components of GCS?
- no movements
- Extension to painful stimulus (decerebrate response)- arms are like E’s (Extension)
- Abnormal flexion to painful stimulus (decorticate response)- arms are like C’s (towards the cord)
- Flexion, withdrawal to painful stimuli
- Localizes painful stimuli
- obeys commands
Where is Wernicke’s where is brocas?
Wernicke’s aphasia is due to a lesion of the superior temporal gyrus
Brocas aphasia is due to lesion in inferior temporal gyrus
What does UFH need to be tested with?
APPT