passmed Flashcards
aortic dissection patho + associations
tear in TUNICA INTIMA of wall of AORTA ASSOC: -HTN (most imp RF) -trauma -bicuspid aortic valve -collagens - MS, EDS -Turners + Noonans -pregnancy -syphillis
aortic dissection features
chest/back pain TEARING + radiates to intrascapular region
pulse DEFICIT - weak or absent carotid, brachial, or femoral pulse, variation (>20 mmHg) in SBP bet the arms
Aortic REGURGITATION (EDM, LLSE) - from prox dissection involving aortic valve leaflets
HTN
Other features -
-coronary arteries –> angina
-spinal arteries –> paraplegia
-distal aorta, subclavian or femoral a –> limb iscahemia
-renal arteries –> anuria + loin pain
-mesenteric arteries –> abdo pain
minority of pts get ST elevation in inferior leads
aortic dissection classification
Stanford classification:
type A - asc aorta - 2/3 of cases
type B - desc aorta - distal to left subclavian origin - 1/3 cases
aortic dissection Ix + Mx
It’s imp to remember that pts may pres acutely and be clinically unstable.
Ix:
1.CXR - widened mediastinum
2.CT angiography of the CAP is the Ix of choice
suitable for stable pts + for planning surgery
-a false lumen is a key finding in diagnosing aortic dissection
3.TOE - more suitable for unstable pts who are too risky to take to CT scanner
Mx:
Type A: surgical MX, but BP should be controlled to a target systolic of 100-120 mmHg whilst awaiting intervention
Type B*: conservative management, bed rest, reduce blood pressure, IV labetalol to prevent progression
HHS pathophysiology + does it have higher or lower mortality than DKA
PATHO: Hyperglycaemia results in OSMOTIC DIURESIS with assoc LOSS of SODIUM + POTASSIUM
- Severe volume depletion results in a significant raised serum osmolarity (typically > than 320 mosmol/kg), –> in HYPERVISCOSITY of BLOOD.
- Despite these severe electrolyte losses and total body volume depletion, the typical patient with HHS, may not look as dehydrated as they are, because hypertonicity–> to preservation of INTRAVASCULAR VOLUME.
-HIGHER mortality than DKA + may be complicated by vascular complications eg MI, stroke or peripheral arterial thrombosis
HHS features occur over days 4x main categories
General - fatigue, lethargy, N+V
Neuro - alt level of consciousness, H, papilloedema, weakness
Haem - hyperviscosity (–> MI, Stroke + peripheral arterial thrombosis)
CV - dehydration, hypotension, tachy
HHS Dx
- Marked HYPERGLYCAEMIA (>30 mmol/L)
- Raised SERUM OSMOLARITY (> 320 mosmol/kg)
- Hypovolaemia in absence of ketoacidosis (pH>7.3, HCO3 >15)
Note: A precise definition of HHS does not exist, however the above 3 criteria are helpful in distinguishing between HHS and DKA. It is also IMP to remember that a mixed HHS / DKA picture can occur.
HHS goals of mx summary
The goals of management of HHS can be summarised as follows:
1. Normalise the OSMOLALITY (gradually)
the serum osmolality is the key parameter to monitor
if not available it can be estimated by 2 * Na+ + glucose + urea
2. Replace FLUID and electrolyte losses - 1st line = IV 0.9% NaCl initially 1L over 1-2hrs
3. Normalise blood glucose (gradually)
Tx of thyroid storm (from untreated hyperthyroidism) TRIAD
Conservative measures - FLUIDS, COOLING
- Propanolol
- PTU (propylthiouracil)
- Steroids
digoxin poisoning presentation
dizzy, N+V
palps
bradycardia (w/o hypotension)
YELLOW-GREEN colour disturbance (xanthopsia)
VISUAL HALOES
confusion
HYPERkalaemia (nb. hypokal = RF for toxicity)
ECG - downsloping ST segment = Salvador Dali moustache or REVERSE TICK SIGN
digoxin poisoning mx
- Immediate digoxin level
- IV fluds
- correct elctrolyte abn
- cont cardiac monitoring
- give DIGIBIND if levels >15 after 6h of last dose, level>10 within 6h of last dose, symptomatic
charcots triad of ascending cholangitis
- RUQ pain
- Fever/raised WCC
3.Jaundice
= infection of the bile duct
Reynolds Pentad
- RUQ pain
- Fever/raised WCC
3.Jaundice
+ SHOCK (low BP)
+ ALTERED MENTAL STATE
= greater severity of infection
what is best prognostic marker in paracetamol OD
PROTHROMBIN TIME
- marker of clotting function = synthetic ftn of the liver
- Kings college criteria can be used in pts with acute liver failure to assess prognosis + assessement for liver transplant
define + mx of Torsades De Pointes
=rare, polympohic VT where QRS axis is constantly shifting + typically prolonged QTc interval on ECG >0.45s
UNSTABLE pts with haemodynamic compr = DC cardioversion
STABLE pts - IV Mg Sulphate 2g over 1-2 mins
