acid/base, afib, CAD, HIV

Question 1

winter’s formula and interpretation

Answer 1

pC02= (HCO3 x 1.5) +8 +/- 2

if CO2 higher than the range, then there’s primary resp acidosis.
if within that range, there’s a compensation.
if below, then primary resp alkalosis

Question 2

5 steps for acid base problems

Answer 2

1) acidosis or alkalosis? look at pH. make sure pH is correct with this formula: H+= 24 (pCO2/HCO3)
2) resp or metabolic?
3) compensation
4) anion gap?

5)if anion gap, does change in AG=change in HCO3
if not, explain excess loss of HCO3

Question 3

compensation rules: metabolic acidosis

Answer 3

winter’s formula

Question 4

compensation: resp acidosis

Answer 4

ACUTE: pH drops by 0.08 units and HCO3 increases by 1 mEq/L per 10 mmHg increase in PaCO2 (up to a
PaCO2 of 70)

CHRONIC: pH drops by 0.03 units and HCO3 increases by 3-4 mEq/L per 10 mmHg increase in PaCO2 (up
to a PaCO2 of 70)

In general, if the HCO3 is above 30, look for a second process (chronic respiratory acidosis, concomitant
metabolic alkalosis).

Question 5

do most patients with asthma attack have resp acidosis or alkalosis

Answer 5

resp alkalosis

Question 6

when to usually get an ABG?

Answer 6

no history, metnal status changes

theyre on a vent

if #s in BMP dont make sense with diagnosis

Question 7

CHADSVASc score

Answer 7

C-CHF
H-HTN
A- age (>65-1, >75-2)
D- DM
S-Stroke (2)
V-vascular dz (MI, aortic atheroma, PVD)
S-sex (female-1)

Question 8

chadsvasc score point system

Answer 8

> 2- anticoagulate
1-2- consider anticoagulation or aspirin
0-aspirin or none

Question 9

rate control drugs

Answer 9

*beta blockers
*CCB- diltiazem, verpapamil
digoxin- adjunct
amiodarone- if others failed

Question 10

rhythm control drugs

Answer 10

class 1C (flecainamide and propafenone)

class 3- amiodarone, sotalol, dofetilide

Question 11

what can you do before cardioversion to prevent someone getting stroke if they have a preformed clot?

Answer 11

3-4 weeks of anticoagulation

or TEE

Question 12

rate or rhythm control for asymptomatic afib?

Answer 12

rate control drugs

Question 13

management for unstable afib

Answer 13

synchronized cardioversion

Question 14

management fot stable afib

Answer 14

1. rate control
2. evaluate need for anticoagulation (chads2vasc)
3. rhythm control (pharm or pacemaker)

Question 15

contraindications to cardioversion

Answer 15

hypokalemia

digitalis toxicity

Question 16

ablation of afib is for paroxysmal or chronic afib?

Answer 16

paroxysmal

Question 17

bruit is what?

Answer 17

turbulent flow from atherosclerosis

Question 18

S4

Answer 18

atrial contraction against stiff heart at end of diastole

Question 19

WHO’s definition of MI

Answer 19

need 2/3:

• biomarkers
• EKG changes
• clinical hx of substernal chest pain

Question 20

what time frame can you get thrombolytic therapy vs angioplasty in acute MI

Answer 20

thrombolytic- within 30 min

angioplasty- within 90 min

Question 21

indications for CABG

Answer 21

50% stenosis of left main artery

3 main vessels involved with reduced EF

Question 22

medications to give during acute MI

Answer 22

beta blocker
aspirin
nitroglycerin
heparin

Question 23

what meds to give someone on discharge after MI

Answer 23

beta blocker
aspirin
ACEI
statin

Question 24

what age to test for HIV once?

Answer 24

13-64

Question 25

do you need consent to test for HIV if medically indicated?

Answer 25

no

Question 26

what testing is performed for HIV?

Answer 26

• 4th gen: combo antigen and antibody test (p24)

- PCR NAAT- >1 week after infection

Question 27

initial lab workup for newly diagnosed patient with HIV

Answer 27

CD4#
toxo
RPR, G/C
hep B, C
TB
CMP, lipids for meds
genotype to determine treatment resistance

Question 28

diagnosing syphilis

Answer 28

1) RPR- nonspecific- detects anti-cardiolipin

2) FTA-Ab - specific - to confirm

Question 29

how can response to treatment of syphilis be assessed?

Answer 29

serial RPR- 4x decline is treated

Question 30

what treatment for syphilis if patients allergic to PCN

Answer 30

1) desensitize to PCN and treat

2) doxycycline

Question 31

legionella diagnosed with

Answer 31

urinary antigen test

Question 32

dx and tx of PJP

Answer 32

dx- direct fluor ab PJP- or sputum PCR

tx: *bactrim, atovaquone, clinda, primaquine

Question 33

what are the indications for steroid use in management of PJP?

Answer 33

paO2<70

Aa>35

Question 34

prophylaxis for PJP- when to start, when to stop

Answer 34

start: CD4<200 or thrush, night sweats
stop: until CD4>200 for 3 months or on anti-retrovirals

Question 35

what meds for prophylaxis for PJP

Answer 35

• bactrim

others: dapsone, atovaqone, pentamidine