Transcript INTRODUCTION to EVIDENCE BASED MEDICINE

Evidence based medicine and
neurotrauma
(Medicina bazirna na
činjenicama i neurotrauma)
Univ.Doc. Dr.Med. Martin Rusnak, CSc
Int. Neurotrauma Research Organization
Vienna, Austria
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http://www.igeh.org/
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Hippocrates
“There are, in effect, two things, to know and to
believe one knows; to know is science; to
believe one knows is ignorance.”
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Medical Mistakes
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the National Institute of Medicine found that
medical mistakes kill somewhere between
44,000 and 98,000 people (average: 71,000)
in hospitals in the U.S. each year
on average, one out of every 500 people
admitted to a hospital in the U.S. is killed by
mistake
the chance of being killed in a commercial
airline accident is one per 8 million flights
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Healthcare Quality
is the degree to which health services for
individuals and populations increase the
likelihood of desired health outcomes and
are consistent with current professional
knowledge
Lohr KN, Harris-Wehling J. Medicare: a strategy for quality assurance.
Quarterly Review Bulletin 1991;17,(1):6-9.
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Improving Quality of HC
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creativity and motivation among healthcare
workers of all kinds;
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leadership is an essential ingredient of
success: senior managers feel personally
responsible for each error;
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the problem is not fundamentally due to lack
of knowledge; we already know far more
than we put into practice.
Based on Lucian Leape and Donald Berwick: Safe health care: are we up to it? We have to
be. Editorials BMJ 2000;320:725-726 ( 18 March )
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ISSUES
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TBI - What are the problems?
TBI management strategies
Introduction into EBM
TBI treatment in reality
How to use EBM for continuous quality
improvement in the care of TBI patients
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TBI: Treatment Goals
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TO KEEP THE PERMANENT NEURO
DEFICIT AT THE LEVEL DEFINED BY THE
PRIMARY INJURY
TO AVOID COMPLICATIONS
TO RECOGNIZE IMMEDIATELY
TO TREAT WITHOUT DELAY
SECONDARY BRAIN INSULTS
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Secondary Brain Insults
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HYPOTENSION (SAP < 90)
HYPOXIA (paO2 < 60, SaO2 < 92)
GLOBAL ISCHEMIA (CI < 2, CPP < 50)
REGIONAL ISCHEMIA (vasospasm)
ANEMIA (Hct < 30, Hb < 10)
HYPERCARBIA (pCO2 > 40)
HYPERTHERMIA (BT > 37.5)
Chesnut RM, New Horizons 1995; 3:366-375
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„Classical“ Treatment
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Analgesia, sedation, anesthesia, relaxation
Intubation, hyperventilation
Head elevation 30°
Normovolemia, normotension
Osmotherapy accoring to monitored ICP
values
Main goal: „normal“ intracranial pressure
Marshall LF, Bowers SA; Clin Neurosurg 1982; 29:312-315
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Treatment in Birmingham, Ala.
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Anesthesia, sedation, relaxation
Normoventilation
Supine position, no head elevation
Hypervolemia, vasopressors, inotropes to achieve
and maintain CPP > 70 (more often > 90) mmHg
Treatment of raised ICP with osmodiuretics only, all
other options are forbidden because of the risk of
hypotension
Main goal: normal cerebral perfusion pressure
Rosner MJ, et al, J Neurosurg 1995; 83:949-954
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Treatment in Lund, Sweden
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Barbiturate anesthesia, analgesia
Intubation, normoventilation
"relative" hypotension, hypovolemia
Control of MAP with clonidine and ß-blockers; CPP
maintained at 50 mmHg
Hyperosmolarity (Na = 150 mmol/l)
Steroids, paracetamol, cooling to 35 °C
Achieve vasoconstriction
Main goal: minimal hydrostatic brain edema
Asgeirsson B, et al; Intensive Care Med 1994; 20:260-267
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Optimal Treatment ?
„Optimal ICP“ ?
 „Optimal CPP“ ?
 “Optimal O2ER“ ?
 „Edema prevention“ ?
All centers have documented that their
treatment strategy is superior to
published results from other centers /
groups
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So what?
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Every center has its own standards
Most centers see only few patients
Comparison of results between centers are rare
Approach Suggested
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Creation of an (inter)national database to collect
patient data from different centers
Data can be used for quality assurance programs
Introduction of guidelines and clinical pathways
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Available Guidelines
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“Guidelines for the Management of Severe Head
Injury” (1995), published in major journals, revised in
1997
Formulated by the “Joint Section on Neurotrauma
and Critical Care” of the AANS and CNS
Reviewed & discussed in:
 New Horizons Vol. 3, #3, August 1995
 J Trauma, Vol. 42, #5, Supplement May 1997
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Other Guidelines
European Brain Injury Consortium (EBIC)
 Scandinavian Guidelines
 Other national guidelines
Most guidelines were created using the same
process (EBM)and the same published
evidence, and therefore came to similar
conclusions
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Evidence Based Medicine
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Basis for decisions in medicine
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What is EBM?
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Safety (?), quality, standardisation (?)
How to use EBM?
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Principle, methods, problems
Why use EBM?
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„clinical experience“, EBM criteria
Individual Search Strategies
Standards & Guidelines, Clinical Pathways
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MY
EXPERT
OPINION
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Randomized
controlled
trial
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Practice Parameters
Strategies of patient management developed
to assist physicians in clinical decision-
making.... including standards, guidelines
and options
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Practice Standards
Based on strong evidence
Accepted principles of patient management
that reflect a high degree of clinical certainty
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Practice Guidelines
Based on weaker evidence
Recommendations for patient management
that reflect a particular strategy or range of
management strategies that themselves
reflect a moderate degree of clinical certainty
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Practice Options
Based on weakest evidence
Other strategies for patient management for
which the clinical utility is uncertain (i.e.,
based on inconclusive or conflicting evidence
or opinion)
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Relationship between Evidence
and Guidelines
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Guidelines should be related to scientific and clinical
evidence
Empirical evidence should take precedence over
expert judgment
A thorough review of the literature should precede
guideline development
The scientific literature should be evaluated and
weighted
Evidence must be ranked and linked to strength of
guidelines
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Studies
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Case Report
CS
Case Report
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Case Series
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Guideline recommendations
Guideline recommendations focus on the usual
management of the average patient with a
specific disorder and are not expected to be
applicable to every patient because of the
complexity of human biology and the
fragmented nature of medical knowledge.
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Purpose
Guidelines may serve to reduce practice
variation, enhance care continuity, and improve
interprovider communication during the care
process, especially when decisions are made
and services rendered by multiple providers
and in different care settings
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Quality of a Guideline
The quality of a guideline is measured in terms
of clarity, clinical applicability, flexibility,
reliability and reproducibility both for the
individual guideline recommendations and for
their coherent integration into a functional form
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Quality of Guidelines
Attributes of guidelines quality are assessed
objectively by quantitating their impact on
measured outcomes of care.
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AUSTRIA, VARIATION IN TREATING TBI
ICP MONITORING
No. of
Departments
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% of ICP
monitoring
0-24
25-69
70-100
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Brain Pressure Monitoring and
Outcome in Britain (Murray, Teasdale, et.al., 1999)
Hospitals:
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Glasgow Edinburgh Liverpool Southampton
(N=384) (N=262) (N=214)
(N=128)
% monitored
29%
55%
0%
38%
% Good
recovery or
Moderate
disability
45%
46%
32%
41%
% Severe
disability
17%
10%
20%
23%
%
Dead/vegetative
38%
44%
45%
34%
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University of Luisville, Kentucky, 2001
Pre-TBI
Post-TBI
Guidelines Guidelines
Intensive
Care Days
21.2
16.8
Reduction
22 %
Ventilator
Days
14.4
11.5
Reduction
24 %
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22.5
Reduction
27 %
Rehabilitation
Service Days
Overall in Hospital Cost per
Survivors
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%
Change
Reduction
20 %
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ICP and OUTCOME Austria
ICP>25
mmHg
Improved
Not
Improved
Died
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P(α=0.025)
Test value
<3 hours
>= 3 hours
No
<3 hours
>= 3 hours
No
<3 hours
>= 3 hours
No
0.05
0.001
n.s.
n.s.
n.s.
n.s.
0.05
0.0001
0.01
OR
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0.146
2.98
0.5
0.79
1.76
0
24.93
0.09
CI at 95% OR
1,112 89,949
0,044 0,482
0,892 9,935
0,055 4,585
0,227 2,777
0,474 6,544
0
2,989 208,003
0,010 0,720
ICP > 25 for less then 3 hours increases chances of good outcome
10 times; chances of death 25 times if increased for more then 3
hours consecutively
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SYSTOLIC BLOOD PRESSURE < 90 mmHg and
DEATH Nove Zamky
Day of
Follow-up
1
χ
Hours
P
(α=0.025)
2
CI 95% OR
O
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U
p
p
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SBP less then 90 mmHg for more then 3 hours
significantly increases chances of death
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w
e
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2
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r
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CQI: Cont.Quality Improvement
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Analysis of outcomes and
treatment strategies
Research
Comparison to other dpts (pooled
data, or „best Dpt“ data)
Development of strategies to
improve performance (together
with IGEH)
Guideline
Implementation of improvement
strategies
Implementation
Re-evaluation.....................
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Vision
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Guidelines define goals but (usually) DO
NOT explain how to reach these goals
One of the most important steps in our
project will be to develop, implement and test
„clinical pathways“
Clinical pathways should explain how to
reach the goals defined by the guidelines
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Int. Neurotrauma Research Org.
is a collaborative non-profit, non-governmental
organization (NGO) based in Vienna, with it
activities directed internationally
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MISSION
Improve the recovery of patients who suffer a
brain or spinal cord injury through helping
hospitals implement evidence-based medical
care, assisting in the reengineering of their
trauma systems to better treat neurotrauma
patients and collaborating on clinical research
to continuously improve the scientific
foundations of evidence-based guidelines and
protocols.
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FELLOWSHIPS
IGEH / INRO hosts fellows from Europe and
helps applicants in identification of grants and
support application development
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THANK YOU
I LOOK FORWARD TO
WORK WITH YOU ON
THIS FASCINATING
PROJECT
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