GUIDELINES FOR PREHOSPITAL MANAGEMENT OF TRAUMATIC BRAIN INJURY

1. GUIDELINES FOR PREHOSPITAL MANAGEMENT OF TRAUMATIC BRAIN INJURY Brain Trauma Foundation PROVIDER COURSE

2. Lesson 1 Things are not always as they appear… Assessment

3. Assessment Objectives • Describe the signs and symptoms of hypoxia in TBI • Approximate the SaO2 by pulse-oximetry and assessment of clinical signs • Discuss the effects of hypotension on the TBI patient

4. Assessment Objectives • Calculate an accurate GCS score • Name a GCS score that indicates severe TBI • Differentiate between flexor/decorticate and extensor/decerebrate posturing • Perform an accurate pupil exam • Identify prehospital signs of herniation

5. Definitions • Oxygenation: delivery of oxygen to tissues from red blood cell hemoglobin • Hypoxia: inadequate level of oxygen available to tissues • Oxygen Saturation: percent of hemoglobin that is saturated with oxygen; measured by oximetry • Ventilation: movement of air in and out of the lungs

6. Airway • Maintain C-spine precautions • Determine that airway is open • Assess the need for artificial airway • Assess every 5 minutes and as needed

7. Breathing • Assess rate, depth, quality, and effectiveness of ventilation every 5 minutes and as needed • Hypoxia occurs in 40% of severe TBI • Assess for hypoxia

8. Pulse Oximetry

9. Circulation for hypotension • Look for visible signs of “shock” • Assess SBP every 5 minutes & as needed • Adult critical threshold level < 90 mm Hg • Child and infant levels are lower • Use age/size appropriate BP cuff Delayed Resuscitation and Hypotension

10. SBP Thresholds • Hypotension should be considered according to age groups: • <65 mmHg (0-1 year) • <75 mmHg (2-5 years) • <80 mmHg (6-12 years) • <90 mmHg (13-16 years) • Adult hypotension • systolic blood pressure <90 mmHg

11. Mean Arterial Pressure MAP = (SBP + 2DBP) 3 Mean Arterial Pressure is somewhere between systolic and diastolic pressures

12. Cerebral Perfusion Pressure MAP – ICP = CPP Take Home Message: Maintaining Blood Pressure is Critical 70 – 30 = 40 CPP of 60 = the critical minimum threshold

14. D - Level of Consciousness • Level of consciousness is an important predictor of TBI GCS

15. Glasgow Coma Scale • A reproducible measure of level of consciousness • Assess every 5 minutes & as needed • Deterioration by 2 or more points is significant The ONLY meaningful measure for TBI

16. Use It Right!!! • After initial assessment • After airway, breathing and circulation • Prior to sedation and muscle relaxants

17. GCS – Adult & Child Eye Opening 4 spontaneous 3 to speech/sound 2 to pain 1 no response Verbal Response 5 oriented 4 confused 3 inappropriate 2 incomprehensible 1 none Motor Response 6 obeys 5 localizes 4 withdraws from pain 3 abnormal flexion 2 abnormal extension 1 no response Total = E + V + M

18. GCS Motor Scale Motor Response 6 obeys 5 localizes 4 withdraws from pain 3 abnormal flexion 2 abnormal extension 1 no response

19. GCS – Infant Full verbal score (5) is assigned for spontaneous cooing after stimulation in children < 2 yrs old Eye Opening 4 spontaneous 3 to speech/sound 2 to pain 1 no response Verbal Response 5 coos or babbles 4 irritable crying 3 cries to pain 2 moans to pain 1 none Motor Response 6 obeys 5 localizes 4 withdraws from pain 3 abnormal flexion 2 abnormal extension 1 no response Total = E + V + M

20. GCS Indicators of TBI Severity • GCS 14-15 --- MILD • GCS 9-13 --- MODERATE • GCS 3-8 --- SEVERE

21. GCS Reliability • Most widely employed method for reporting serial neurologic evaluations • Indicator of level of consciousness & head injury severity • Moderately reliable by prehospital emergency medical care providers1 • A single field measurement of the GCS cannot predict outcome • Menegazzi JJ, Davis EA, Sucov AN, et al: Reliability of the Glasgow Coma Scale when used by emergency physicians and paramedics. J Trauma 1993; 34:46-48

22. Admission GCS • In a severe TBI patient, a decline in the GCS score over time can be indicative of the need for acute management and neurosurgical intervention1 Field ED Mortality Surgical Evacuation 8.4 6.7 56% Yes 7.2 7.2 20% No • Servadei F, Nasi MT, Cremonini AM, et al: Importance of a reliable admission Glasgow Coma Scale score for determining the need for evacuation of posttraumatic subdural hematomas: A prospective study of 65 patients. J Trauma 1998; 44:868-873

23. Pupil Response • Assess every 5 minutes & as needed • Pupil size • Symmetry • Reactivity to light

24. Measuring Pupil Response Document these findings: • Bilateral symmetry (asymmetric pupils differ more than 1 mm) • Reactivity to light (a fixed pupil shows <1mm change in response to bright light) • Dilation (greater than or equal to 4mm diameter in adults)

25. Research Findings In-Hospital Studies • Single fixed and dilated pupil • 45% poor outcome • Bilateral fixed and dilated pupils • 82% poor outcome Braakman R,Gelpke G, Habbema J, et al. Systemic selection of prognostic features in patients with severe head injury. Neurosurgery 6: 362 – 370, 1980

26. Conditions that can mimic pupil abnormalities: Pupil Abnormalities • hypoxia • hypothermia • orbital trauma • pharmacological treatment • cataract surgery • hypotension • illegal drug use • toxic exposure • artificial eye • congenital abnormality • anisocoria

27. Blown Pupil • Suggests herniation, which is compression of the brain stem • Usually indicative of same- side mass • Treat increased ICP, hypoxia & hypotension

28. Indicators of Herniation An unresponsive patient (comatose) with: Bilateral dilated unresponsive pupilsORAsymmetric pupils AND Abnormal extension (decerebrate posturing)ORNo motor response to painful stimuli

29. Take Home Messages • ABCs • Level of Consciousness – GCS • Herniation – Pupils and Motor Exam • Thresholds: 90 / 90 / 9 • Use assessment to determine treatment

30. GCS Skills Practice • Video • Break into small groups

31. Lesson 2 Treatment

32. Treatment Objectives • Demonstrate normal and hyperventilation rates for adults and children • Describe proper fluid resuscitation in TBI • List two field treatments for brain herniation

33. Treat Airway • Protect C-spine alignment • Airway support per scope of practice • Intubate severe TBI patients • Correct hypoxia • Consider C-spine and facial trauma

34. When should you intubate? GCS < 9 (severe TBI)

35. Treat Breathing • Rate, depth, quality, and effectiveness • Administer oxygen • Appropriate ventilation rate… • Age • Herniation

36. SaO2 at Scene of Accident Oxygen SaturationMortalitySevere Disability >90% 14.3% 4.8% 60-90% 27.3% 27.3% <60% 50.0% 50.0% Stocchetti N, Furlan A and Volta F: Hypoxemia and arterial hypotension at the accident scene in head Injury. J Trauma 40: 764-767, 1996

37. Total number of severe head injury patients in study was 717. Chesnut RM, Marshall LF, Klauber MR, et al. The role of secondary brain injury in determining outcome from severe brain injury. J Trauma 34: 216-222, 1993

38. Normal Ventilation Rates Approximate normal ventilation rates: • 10 bpm Adult • 20 bpm Child • 25 bpm Infant

39. CO2 and Hyperventilation • Hyperventilation produces a rapid decrease in the arterial partial pressure of carbon dioxide, which causes cerebral vasoconstriction, decreased cerebral blood flow, and lower intracranial pressure (ICP), giving the brain more room to swell. • Hyperventilation can decrease the cerebral blood flow, potentially to the point of ischemia. • Take Home Message: Monitor End-Tidal CO2 closely if capnography is available.

40. Hyperventilation and the Brain Injured Patient • Important Points: • Research identifies potential harm that can come from hyperventilating a TBI patient without signs of brain herniation • Hyperventilation is a short term measure used in specific severe TBI patients (herniation) until definitive diagnostic or therapeutic interventions can be initiated.

41. Hyper-Ventilation Rates Approximate hyper-ventilation rates: • 20 bpm Adult • 30 bpm Child • 35 bpm Infant

42. Capnography and End-Tidal CO2 • Continuous end-tidal CO2 measurements are used to measure the adequacy of ventilation. Many systems require a measurement of end-tidal CO2 after endotracheal tube placement as a method to confirm appropriate tube placement. • Does not correlate perfectly with PaCO2. The level of CO2 measured by capnometry approximates 2 to 5 torr above or below the level in arterial blood, but is not as accurate. • For hyperventilation, aim for a CO2 around 35 mmHg. Below 30 mmHg is considered severe hyperventilation. Below 25 mmHg is not recommended.

43. Take Home Messages • Early post-injury episodes of hypoxia greatly increase mortality and morbidity • Evidence defines hypoxia as an oxygen saturation <90% • Intubating unconscious and unresponsive TBI patients improves outcome

44. Ventilation Rates Practice Match your bag squeeze rate to the audio tape rate

45. Treat Circulation - Hypotension • Maintain SBP > 90mmHg in adults (lower for infants and children) • Use isotonic IV fluids

46. Fluid Resuscitation Infuse volume to achieve normal BP

47. Total number of severe head injury patients in study was 717. Chesnut RM, Marshall LF, Klauber MR, et al. The role of secondary brain injury in determining outcome from severe brain injury. J Trauma 34: 216-222, 1993

48. Take Home Messages • Evidence defines hypotension as a single observation of SBP < 90mm Hg (in adults) • A single episode of hypotension doublesmortality and increases morbidity • Goal is to maintain SBP >90mmHg in adults

49. Brain-Targeted Therapy • Glucose for hypoglycemia • Sedatives for agitation • Analgesics for pain • Paralytics for ET intubation • Controversial: • Mannitol • Lidocaine • Hypertonic Saline

50. Other Factors Affecting ICP • Fear and anxiety • Pain • Vomiting • Straining • Environmental stimulation • Endotracheal intubation • Airway suctioning Significance of these factors is largely unknown in terms of outcome