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Traumatic Brain Injury and Evidence Based Medicine

Traumatic Brain Injury and Evidence Based Medicine. TBI - What are the problems? TBI management strategies TBI treatment in Austria Introduction into EBM How to use EBM for continuous quality improvement in the care of TBI patients. TBI: Treatment Goals.

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Traumatic Brain Injury and Evidence Based Medicine

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  1. Traumatic Brain Injury andEvidence Based Medicine • TBI - What are the problems? • TBI management strategies • TBI treatment in Austria • Introduction into EBM • How to use EBM for continuous quality improvement in the care of TBI patients

  2. TBI: Treatment Goals • TO KEEP THE PERMANENT NEURO DEFICIT AT THE LEVEL DEFINED BY THE PRIMARY INJURY • TO AVOID • TO RECOGNIZE IMMEDIATELY • TO TREAT WITHOUT DELAY SECONDARY BRAIN INSULTS

  3. Secondary Brain Insults • 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

  4. Treatment in Anytown / USA • ICP monitoring in 50% of centers • ICP monitoring in 25% of cases • Osmodiuretics in 83% of the centers • HV to 25 mmHg in 54% of the centers • HV < 25 mmHg in 29% of the centers • Steroides in 64% of cases • Barbiturate in 33% of the centers • Dehydration in > 90% of cases Ghajar J, et al, Crit Care Med 1995; 23:560-567

  5. „Classical“ Treatment • 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

  6. Treatment in Birmingham, Ala. • 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

  7. Treatment in Philadelphia, Pa. • Sedation, analgesia, no relaxants • Intubation, hyperventilation • Normovolemia, normotension • Head elevation 30° • Jugular bulb catheter to monitor cerebral oxygen extraction • Hyperventilation to achieve / maintain "normal" oxygen extraction ratio (pCO2 < 20 mmHg!) • Main goal: normal cerebral O2ER Cruz J, et al, Crit Care Med 1993; 21:1242-1246

  8. Treatment in Lund, Sweden • 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 • DHE to achieve vasoconstriction • Main goal: minimal hydrostatic brain edema Asgeirsson B, et al; Intensive Care Med 1994; 20:260-267

  9. 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

  10. Treatment of severe traumatic brain injury in Austria (1998) H. Drobetz, B. Freudenschuß, E. Kutscha-Lissberg, W. Buchinger, W. Mauritz

  11. Austrian ICUs surveyed (n = 60) • Mostly run by anesthesiologists, all contacted by phone (for treatment data) • Phone calls (for patient statistics) to all Departments of • Trauma Surgery • Neurosurgery • Surgery

  12. Patient numbers/ICU/1997 60% Operative (n = 41/60) 54 50% Conservative (n = 32/60) 40% 41 GCS < 8 (n = 52/60) 30% 31 27 20% 20 19 17 16 15 13 13 10% 12 12 9 0% 0 - 10 11 - 20 21 - 30 31 - 50 > 50

  13. Surgical Treatment 4% Trauma surg. Neurosurg. 29% Surgeon 82%

  14. Prehospital Treatment • GCS 90% (n = 51/60) • MAP, HR, SaO2 100% (n = 44/60) • Intubation 74% (n = 47/60)

  15. Prehospital „small volume resuscitation“ and steroids (n = 50/60) 70% SVR 50% Steroids 32% 12% 12% 10% 6% 6% never rarely frequently usually

  16. ICP Monitoring in Austria 10 - 100% 1

  17. ICP Monitoring Trauma Surgeons (15-100%) n = 31 40,21% Neurosurgeons (13-100%) n = 7 77,21%

  18. ICP Monitoring Devices 91% (n = 46/60) 41% 24% 15% 11% Epidural Ventricle different Parenchym Subdural

  19. ICP Monitoring - Side uninjured injured 59% 34% both 7%

  20. Hyperventilation (n = 52/60) 94% 79% Hyperventilation to 30 mm Hg CO2 Hyperventilation 25 - 30 mm Hg CO2 Hyperventilation < 25 mm Hg CO2 44% 21% 19% 15% 13% 4% 2% 8% never rarely frequently usually

  21. Steroids at the ICU (n = 52/60) 65% 19% 10% 6% frequently usually never rarely

  22. Osmotherapy (n = 52/60) 50% 27% 15% 8% never rarely frequently usually

  23. Barbiturate Treatment (n = 52/60) 46% 31% 12% 12% never rarely frequently usually

  24. So what? • Every center has its own standards • Most centers see only few patients • Comparison of results between centers are rare Approach: • 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

  25. Available Guidelines • “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

  26. 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

  27. Evidence Based Medicine • Basis for decisions in medicine • „clinical experience“, EBM criteria • What is EBM? • Principle, methods, problems • Why use EBM? • Safety (?), quality, standardisation (?) • How to use EBM? • Individual Search Strategies • Standards & Guidelines, Clinical Pathways

  28. Clinical Experience (1) Is the (partially sub-cortically) available summary of • Knowledge of pathophysiology (basic knowledge) • Medical tradition (e.g. Dopamin) • Training • Analogies (treatment results in similar cases) which forms the basis for daily decisions.

  29. Clinical Experience (2) • Advantages: • Increases with age • Available immediately and everywhere • Usually sufficient • „flexible“ compared to EBM • Disadvantages: • Huge individual differences • Errors may have a long tradition, too • Acceptance of new findings may be slow • Effectivity of treatment overestimated

  30. Evidence Based Medicine • Developed by Clinical Epidemiologists from McMaster Medical School, Canada, since 1985 • Positioned as alternative to traditional „opinion-based“ medicine • „best available evidence“ should be the basis for treatment decisions: multi-center PRCT, meta-analysis, guidelines, clinical pathways

  31. What is „evidence“? (1) Clinical experience („non-experimental" evidence) overestimates effectivity: • Treatment successes are remembered more frequently than treatment failures • Patient compliance improves outcome, even with placebo • Many diseases, symptoms or conditions improve anyway • Treatment is never „blind“, and the placebo effect may suggest effectivity

  32. What is „evidence“? (2) EBM criteria: Only "experimental“ evidence (i.e. results from clinical trials) should be used as basis of treatment decisions. "Therapeutic reports with controls tend to have no enthusiasm, and reports with enthusiasm tend to have no controls" Sackett DL, CHEST 1989; 95:(Suppl.) 2S

  33. Levels of evidence Classification of scientific reports: • Prospective randomized controlled trial (PRCT), enough power to limit alpha (false pos) and beta (false neg) error (= large patient numbers, multi-centered) • PRCT with less power • Study with controls not randomized • Study with historic controls • Study without controls; "expert opinion"

  34. Basis for Guidelines • Grade A, Class I evidence: Standards; supported by one or more level 1 studies • Grade B, Class II evidence: Guidelines; supported by one or more level 2 studies • Grade C, Class III evidence: Options; supported by studies classified as level 3, 4, or 5 Sackett DL, CHEST 1989; 95:(Suppl.)2S

  35. EBM - Methods (1) For any questions regarding diagnosis, prognosis or treatement: • Formulate a clear question • Search for relevant studies • Evaluate retrieved studies for validity and usefulness • Use results in clinical practice Rosenberg W, Donald A: Evidence-based medicine: an approach to clinical problem solving. Br Med J 1995; 310:1122-1226

  36. EBM - Methods (2) Evaluation of retrieved studies: • Are the results correct? • Patient sample large enough, representative? • Study groups homogenous? • Collection of patient, treatment and outcome data complete? • Valid criteria used for evaluation? • What are the results? • Incidences of outcomes, complications? • How good are estimates of likelihoods? • Are the results useful? • Is the situation comparable to the study? • Can the results be used in clinical practice?

  37. EBM – Problems (1) • Formulation of a clear question • Easy: scoring systems or grading scales available; high incidence of disease or problem • Difficult: low incidence of disease or problem, no scoring systems or grading scales available • Time factor • Medline search, retrieval and evaluation of studies take time • Equipment factor • Internet, database connections, computers, library services must be available

  38. EBM – Problems (2) • Evaluation of retrieved studies • Easy: guidelines, consensus conference results available • Difficult: individual evaluation; incorrect estimation of probability of outcomes • Not all that can be measured is useful • Not all that is useful can be measured • Lack of evidence of efficiacy is not equal to evidence of lack of efficiacy • How to deal with different level-1 studies

  39. EBM - Problems (3) • Use of selected evidence: even use of „best available evidence“ may lead to errors in management due to • Ignorance of local situation • Application to patients or patient groups who are different from the study group • Overuse of resources in settings where resources are limited

  40. Guidelines • Available for frequent problems • Developed by Consensus Conferences, Working Groups etc • Should be peer/reviewed • Effect of guideline compliance should be evaluated • Should be updated regularely • Non-compliance may lead to litigation!

  41. Published Guidelines for ICUs (n=167; medline 66-9/99)

  42. Why use EBM? • Validity • EBM-Review instead of tradition / opinion • BUT: Application of „best available evidence“ to an individual situation is still a medical decision, and may be wrong • Quality • Critical re-evaluation of clinical practice • Scoring systems, grading scales required • Standardisation • Treatment „state of the art“

  43. How to use EBM? • Clinical experience should be assisted, not replaced by EBM • Use of EBM requires time, patience, good knowledge of English, computer skills, internet and database connections, and critical intellect • EBM-based solutions for critical situations are available ONLY if the hard work is done before • Individual search, use of guidelines and clinical pathways possible

  44. Individual Search • If no guidelines are available • Medline:use different key words for search runs, identify possibly relevant studies • Library: retrieve papers • Evaluate, identify relevant papers • Create treatment algorithm • Implement treatment algorithm • Check results of algorithm implementation

  45. Guidelines • Available for frequent problems • Medline: identify relevant guidelines • Library: retrieve original publication • Create treatment algorithm adapted to local situation (= clinical pathway) • Implement treatment algorithm • Check results of algorithm implementation

  46. Medicl Decisions (1) • Starting point: Problem with diagnosis, prognosis, treatment • Can the problem be exactly defined? • NO: decision according to „clinical experience“ • YES: • Is the problem exactly defined? • NO: try to define the problem • YES:

  47. Medical Decisions (2) • Are guidelines available? • YES: Creation and implementation of algorithm • NO: • Is experimental evidence (PRCT, MA) available? • YES: decision according EBM criteria • NO: decision according to „clinical experience“ – possible approaches should be tested in clinical study

  48. Ultimate Goal of our Project To improve quality of care for brain trauma patients by using evidence based medicine (EBM) and continuous quality management (CQM)

  49. Research Guideline Implementation CQM • Analysis of ICU outcomes and treatment strategies for each ICU • Comparison to other ICUs (pooled data, or „best ICU“ data) • Development of strategies to improve performance (together with IGEH) • Implementation of improvement strategies • Re-evaluation.....................

  50. Outlook • 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 I LOOK FORWARD TO WORK WITH YOU ON THIS FASCINATING PROJECT THANK YOU

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