diagnosis is Flashcards
When interpreting an arterial blood gas, a high serum anion gap is consistent with:
a) lithium toxicity
b) Salicylate toxiticy
c) Hypercholeraemia
d) Hypoalbuminaemia
e) Hypercalcaemia
b) Salicylate toxicity
Salicylate toxicity can cause an elevated serum anion gap due to the production of organic acids (salicylic acid and its metabolites) that are not measured by the standard anion gap calculation. This leads to an increased anion gap metabolic acidosis.
HAGMA results from accumulation of organic acids or impaired H+ excretion
Causes (LTKR)
Lactate
Toxins
Ketones
Renal
Causes (CATMUDPILES)
CO, CN
Alcoholic ketoacidosis and starvation ketoacidosis
Toluene
Metformin, Methanol
Uremia
DKA
Pyroglutamic acidosis, paracetamol, phenformin, propylene glycol, paraladehyde
Iron, Isoniazid
Lactic acidosis
Ethylene glycol
Salicylates
NAGMA results from loss of HCO3- from ECF
Causes (CAGE)
Chloride excess
Acetazolamide/Addisons
GI causes – diarrhea/vomiting, fistulae (pancreatic, ureters, billary, small bowel, ileostomy)
Extra – RTA
Causes (ABCD)
Addisons (adrenal insufficiency)
Bicarbonate loss (GI or Renal)
Chloride excess
Diuretics (Acetazolamide)
LITFL
A patient with a perioperative troponin rise above normal, chest pain, left ventricular
anterior regional wall motion abnormality, and atheroma without thrombus
occluding 70% of the left anterior descending coronary artery has had a/an
NSTEMI
STEMI
Unstable angina
Acute myocardial injury
Chronic myocardial injury
Type 1 MI
Type 2 MI
NSTEMI
MINS: MI/ischemic myocardial injury that doesn’t fulfill MI defn
MI: Myocardial injury with rise/fall cTn above 99th percentile of upper ref limit within 30 days post op plus at least one of:
Ischemic symptoms
New ischemic ECG changes
New path Q waves on ECG
Imaging evidence of myocardial ischemia
Angiographic/autopsy evidence of coronary thrombus
Steph In a patient presenting with an Addisonian crisis, the electrolyte disturbances MOST LIKELY to be seen are:
a) Low BSL, hyperkalaemia, hyponatraemia
b) High BSL, hyperkalaemia, hyponatraemia
c) Hypocalcaemia, hyperkalaemia, hyponatraemia
d) Hypercalcaemia, hyperkalaemia, hyponatraemia
a) Low BSL, hyperkaelamia, hypernatraemia
Adrenal crisis is a medical emergency and should be considered in any patient presenting with one or more of the following symptoms:
* altered consciousness
* circulatory collapse
* hypoglycaemia
* hyponatraemia
* hyperkalaemia
* seizures
* history of steroid use/withdrawal
* any clinical features of Addison disease
Adrenal crisis may be precipitated by stress, sepsis, dehydration or trauma; clinical features may be modified accordingly. In patients with known adrenal insufficiency, nonadherence with therapy, inappropriate cortisol dose reduction or lack of stress related cortisol dose adjustment can cause adrenal crisis.
Aus Family Physician - RACGP
Re chat below - incorrect recall, have updated
A
Why A? All three should be seen - glucocorticoid deficiency causes low Na and glucose while simultaneous mineralocorticoid deficiency low K.
Crisis typically presents with hypotension abdo pain, nausea, vomiting and confusion. No one electrolyte/lab value can tie all those together.
A 55-year-old with no past history of ischaemic heart disease is three days post-total hip replacement surgery. They have an episode of chest pain at rest with features typical of angina that lasts 30 minutes before fully resolving. There are no electrocardiogram changes and no troponin rise. The diagnosis is
a. No diagnosis made
b. Unstable angina
c. STEMI
d. NSTEMI
e. MINS
REPEAT
b. Unstable angina
UTD:
Unstable angina (UA) and acute non-ST elevation myocardial infarction (NSTEMI) differ primarily in whether the ischemia is severe enough to cause sufficient myocardial damage to release detectable quantities of a marker of myocardial injury (troponins):
●UA is considered to be present in patients with ischemic symptoms suggestive of an ACS and no elevation in troponins, with or without electrocardiogram changes indicative of ischemia (eg, ST segment depression or transient elevation or new T wave inversion).
●NSTEMI is considered to be present in patients having the same manifestations as those in UA, but in whom an elevation in troponins is present.
MINS: Myocardial injury after non-cardiac surgery (up to 30 days post-op):
1. Elevated postop troponin
2. Resulting from myocardial ischaemia (i.e. no evidence of a non-ischaemic aetiology), not requiring an ischaemic feature (i.e. no chest pain, no ECG change)
VISION studies (Vascular Events in Noncardiac Surgery Patients Cohort Evaluation) demonstrated that severity of MINS strongly associated with 30-day mortality after NCS.
hs-cTnT
<20ng/L ~ 0.5% 30 day mortality
20-64ng/L ~3% 30 day mortality
65-999 ng/L ~9% 30 day mortality
>1000ng/L ~30% 30 day mortality
Whilst VISION trial identified MINS in at risk patients, the question now becomes what interventions are available to prevent this complication?
Kate
In an adult weighing 70 kg, a bedside assessment of haemodynamic status shows a left ventricular end-diastolic diameter of 2.4 cm. This finding suggests:
a) Hypovolaemia
b) Normal
c) Hypervolaemia
? Normal
Can only find absolute numbers or according to BSA not weight per se
Image
https://thoracickey.com/cardiac-chambers/
PSAX End diastolic AREA:
Hypovolemia <8cm2
Normal 8-14cm 2
Hypervolemia > 14cm2
IVSd and IVSs – Interventricular septal end diastole and end systole. The normal range is 0.6-1.1 cm.
LVIDd and LVIDs – Left ventricular internal diameter end diastole and end systole. The normal range for LVIDd is 3.5-5.6 cm, and the normal range for LVIDs is 2.0-4.0 cm.
LVPWd and LVPWs – Left ventricular posterior wall end diastole and end systole. The normal range is 0.6-1.1 cm.
RVDd – Right ventricular end diastole. The normal range is 0.7-2.3 cm.
Ao Root Diam – Aortic root diameter. The normal range is 2.0-4.0 cm.
LA Diameter – Left atrium diameter. The normal range is 2.0-4.0 cm.
The IVSd and IVPWd measurements are used to determine left ventricular hypertrophy, which is the thickening of the muscle of the left ventricle. LV hypertrophy is a marker for heart disease. In general, a measurement of 1.1-1.3 cm indicates mild hypertrophy, 1.4-1.6 cm indicates moderate hypertrophy, and 1.7 cm or more indicates severe hypertrophy.
Hypovolaemia
Normal for end diastole is 3.5 to 5.6cm
21.2 The image below on the left shows a normal central venous pressure (CVP) trace. The CVP
trace in the image below on the right is most consistent with
a) AF
b) MR
c) AR
d) TR
e) Pericardial constriction
TR
19.2 An 80-year-old woman is admitted to hospital with respiratory failure. Her arterial blood gas on oxygen 4 litres per minute via a Hudson mask is as follows: (ABG shown) Which of the following most accurately describes this blood gas result?
pH 7.2, pO2 91, pCO2 84, BE 16, HCO3- 43, Na 145
a) Metabolic alkalosis, acute resp acidosis + normal AG
b) Metabolic alkalosis resp acidaemia + abnormal AG
c) Mixed acidaemia
d) Respiratory Acidosis with incomplete compensation
e) Compensated Respiratory acidosis
d) Respiratory Acidosis with incomplete compensation
Uncertain of this answer, not enough info to calculate anion gap
pH 7.2 = acidaemia
pCO2 84 = respiratory acidosis
HCO3 43 = metabolic alkalosis as compensation
BE 16 = metabolic alkalosis
Boston rules:
Chronic fully compensated Respiratory acidosis
Expected compensation is 3-4 mmol/L rise for every 10mmHg rise in PCO2.
Expected metabolic compensation therefore is
HCO3 = 24 + 4 x ((84-40)/10)
= 24 + 4x (44/10)
= 24 + 4 x (4.4)
= 24 + 17.6
= 41.6
Metabolic acidosis
PaCO2 should be 1.5 x HCO3 + 8
= 72.5
Rules (from K.Brandis Acid-base rules anaesthesia mcq):
- 1 for 10 (acute resp acidosis), 4 for 10 (chronic resp acidosis)
- 2 for 10 (acute resp alkalosis), 5 for 10 (chronic resp alkalosis)
- 1.5xHCO + 8 = expected pCO2 in a metabolic acidosis
- 0.7xHCO3 + 22 = expected pCO2 in a metabolic alkalosis
https://www.anaesthesiamcq.com/AcidBaseBook/ab9_3.php
