EBM

1
EBM

• PGY1 ???

2
Basic data

• ??????
• ?? Female
• ??? 10741244

3
Clinical problem

• Abdominal pain for days
• gt suspected stool impaction related
• Abdominal wall bulging
• gt suspected hernia
• gt Consult GS

4
Clinical problem

• GS suggestion
• gt suggest abdominal CT scan for evaluation of
  suspecious ventral hernia
• gt Creatinin1.5
• Family was concerned about the possibility of
  contrast-related renal failure

5
Background knowledge

• Types of radiocontrast agents
• First generation - ionic monomers they are
  highly hyperosmolal (1400-1800 mosmo/kg)
• Second generation - nonionic monomers with a
  lower osmolality than the first generation
  (500-850 mosmo)
• The newest nonionic contrast agents -iso-osmolal,
  being dimers with an osmolality of approximately
  290 mosmol/kg

6

• low- and iso-osmolal agents being associated with
  a relatively decreased incidence of renal injury
  among high-risk patients.

7
Background knowledge

• PREVENTION
• There is no specific treatment once
  contrast-induced acute renal failure develops.
• The best treatment of contrast-induced renal
  failure is prevention.

8
Background knowledge

• Overview  
• A variety of preventive measures may reduce
  the risk of contrast nephropathy
• 1.replaced by ultrasonography, magnetic
• resonance imaging or CT scanning without
• radiocontrast
• 2. The use of lower doses of contrast

9
Background knowledge

• 3.Avoidance of volume depletion or
• nonsteroidal antiinflammatory drugs
• 4. administration of intravenous saline or
• possibly sodium bicarbonate
• 5. administration of the antioxidant
• acetylcysteine (Fluimucil)
• 6. use of low or iso-osmolal nonionic contrast
• agents

10
Background knowledge (Acetylcysteine)

• Acetylcysteine is a thiol compound with
  antioxidant and vasodilatory properties.
• A possible mechanism of benefit in
  contrast-induced nephropathy involves minimizing
  both vasoconstriction and oxygen free radical
  generation.

11
Acetylcysteine

• The most commonly studied dose is 600 mg orally
  twice daily.
• on the day before and the day of the procedure to
  patients.
• The benefit of intravenous acetylcysteine
• this remains uncertain.

12
Forground (PICO)
13
Database
14
Search keywords

• Acetylcysteine
• contrast nephropathy

15
Result(1)
16
Article
Acetylcysteine for prevention of contrast
nephropathy Meta-analysis
17
Critical Appraisal of Systematic
Review????????

• Are the results of the review valid (????)?
• What question did the systematic review addressed
  (??????)?
• Is it unlikely that important, relevant studies
  were missed (?????????)?
• Were the criteria used to select articles for
  inclusion appropriate (?????????)?
• Were the included studies sufficiently valid for
  the type of question asked (??????????????)?
• Were the results similar from study to study
  (????????)?
• What were the results (????)?
• How are the results presented (??????)?

18
What question did the systematic review addressed
(PICO)?????????
We aimed to assess the efficacy of acetylcysteine
to prevent contrast nephropathy after
administration of radiocontrast media in patients
with chronic renal insufficiency.
Is it unlikely that important, relevant studies
were missed??????????
To identify relevant studies, we searched
BIOSIS/RRM (1989 onwards), MEDLINE (1966
onwards), Web of Science (1997 onwards), the
Current Contents Medizin (current contents of
medical journals publishing in German language),
and The Cochrane Library (1996 onwards). We
included studies in all languages irrespective
of masking when the following criteria were met
planned as a prospective, randomised, controlled
trial published as an article or abstract
19
Were the criteria used to select articles for
inclusion appropriate ????????? ?
We included studies in all languages irrespective
of masking when the following criteria were met
planned as a prospective, randomised, controlled
trial published as an article or abstract
included patients with chronic renal insufficiency
receiving contrast media intravenously
or intra-arterially for diagnostic or therapeutic
procedures use of acetylcysteine to prevent
contrast nephropathy and development of acute
renal failure after administration of contrast
media as a primary outcome.
20
Were the included studies sufficiently valid for
the type of question asked ?????????????? ?
We included studies in all languages irrespective
of masking when the following criteria were met
planned as a prospective, randomised, controlled
trial
Quality scoring of these trials according to the
Jadad scale was done by the same authors and
agreement was 100 (table 2).
21
(No Transcript)
22
(No Transcript)
23
Were the results similar from study to
study?????????
24
Study design

• a meta-analysis of randomised controlled trials

25
Results

• Compared with periprocedural hydration alone,
  administration of acetylcysteine and hydration
  significantly reduced the relative risk of
  contrast nephropathy by 56 (0435 95 CI
  02150879, p002) in patients with chronic
  renal insufficiency.

26
(No Transcript)
27
Conclusion

• Compared with periprocedural hydration alone,
  acetylcysteine with hydration significantly
  reduces the risk of contrast nephropathy in
  patients with chronic renal insufficiency.
• The relative risk of contrast nephropathy was not
  related to the amount of radiocontrast media
  given or to the degree of chronic renal
  insufficiency before the procedure.

28
(No Transcript)