Severe TBI:BTF Guidelines J. Claude Hemphill III, MD, MAS Associate Professor of Clinical Neurology and Neurological Surgery University of California, San Francisco Director, Neurocritical Care San Francisco General Hospital Disclosures Research Support: NIH/NINDS, Novo Nordisk Consulting: Astra Zeneca, Medivance, Novo Nordisk Stock options: Cardium Therapeutics (Innercool Therapies), Ornim
Why Guidelines? • Framework for care • Reduce heterogeneity • Generate • Interest in the disease • Education for staff and patients/families • Improve outcomes (specifically in TBI) • Elf, Critical Care Medicine, 2004 • Decreasing mortality, increasing favorable outcomes over time • Palmer, J Trauma, 2001 • Following AANS “Guidelines” led to improved outcomes, increased costs • But remember! • Guidelines do not replace judgment and expertise • One size does not fit all • Not punitive
Brain Trauma Foundation Guidelines • Originally in 1995 • Revised in 2000 and 2007 • Developed in response to concerns over heterogeneity in TBI care and lack of aggressive interventions (specifically ICP monitoring) • ICP monitoring in BTF Guidelines “eligible” patients • 1995 32% • 2005 78% • Goal of assessing available evidence • Somewhat less consensus directed than AHA Stroke Guidelines
Salient Differences • Separated out Prehospital and Prognosis into separate BTF guidelines • Separate Surgical Management guidelines • Changed Levels of Evidence and Recommendations • Dropped “stepwise” ICP treatment algorithm to reflect multiple concurrent pathophysiologies • Added sections for • Brain tissue oxygen monitoring • Hypothermia • DVT prophylaxis • Infection Prophylaxis
I. Blood Pressure and Oxygenation RECOMMENDATIONS A. Level I There are insufficient data to support a Level I recommendation for this topic. B. Level II Blood pressure should be monitored and hypotension (systolic blood pressure < 90 mm Hg) avoided. C. Level III Oxygenation should be monitored and hypoxia (PaO2 < 60 mm Hg or O2 saturation < 90%) avoided.
Blood Pressure and Oxygenation • Why this recommendation? • Lots of observational studies finding hypotension and hypoxia are bad • Hypoxia alone is much better tolerated than hypotension • Nobody is going to do a trial of “not treating” hypotension and hypoxia • What does this mean to you for patient treatment? • Avoid hypotension and hypoxia, especially early
II. Hyperosmolar Therapy RECOMMENDATIONS A. Level I There are insufficient data to support a Level I recommendation for this topic. B. Level II Mannitol is effective for control of raised intracranial pressure (ICP) at doses of 0.25 gm/kg to 1 g/kg body weight. Arterial hypotension (systolic blood pressure < 90 mm Hg) should be avoided. C. Level III Restrict mannitol use prior to ICP monitoring to patients with signs of transtentorial herniation or progressive neurological deterioration not attributable to extracranial causes.
Hyperosmolar Therapy • Why? • No randomized trials showing mannitol improves TBI outcome • Mannitol is effective at transiently lowering ICP • Lots of interest now in hypertonic saline • What? • Use mannitol intermittently as part of ICP lowering strategy • Avoid hypovolemia • If you are using mannitol, you should be monitoring ICP
III. Prophylactic Hypothermia RECOMMENDATIONS A. Level I There are insufficient data to support a Level I recommendation for this topic. B. Level II There are insufficient data to support a Level II recommendation for this topic. C. Level III Pooled data indicate that prophylactic hypothermia is not significantly associated with decreased mortality when compared with normothermic controls. However, preliminary findings suggest that a greater decrease in mortality risk is observed when target temperatures are maintained for more than 48 h. Prophylactic hypothermia is associated with significantly higher Glasgow Outcome Scale (GOS) scores when compared to scores for normothermic controls. Comment Regarding Classification of Level of Evidence for Meta-Analyses As stated in the Method Section of this guideline, to determine the recommendation level derived from a metaanalysis, three criteria are considered: (1) are all included studies of the same quality class, (2) are the findings of the studies in the same or contradictory directions, and (3) what are the results of sub-analyses that examine concerns about potential confounding factors? In this meta-analysis, although all included studies were Class II, the sub-analyses findings introduced sufficient concern about unknown influences to render the recommendation a Level III.
Prophylactic Hypothermia • Why? • The one best-designed TBI trial showed no benefit of hypothermia • But some folks just won’t let this go • Contentious issue with conflicting smaller studies and ongoing research • What? • You’re on your own with this one • We don’t use it up front, but may consider it for refractory elevated ICP
IV. Infection Prophylaxis RECOMMENDATIONS A. Level I There are insufficient data to support a Level I recommendation for this topic. B. Level II Periprocedural antibiotics for intubation should be administered to reduce the incidence of pneumonia. However, it does not change length of stay or mortality. Early tracheostomy should be performed to reduce mechanical ventilation days. However, it does not alter mortality or the rate of nosocomial pneumonia. C. Level III Routine ventricular catheter exchange or prophylactic antibiotic use for ventricular catheter placement is not recommended to reduce infection. Early extubation in qualified patients can be done without increased risk of pneumonia.
Infection Prophylaxis • Why? • New topic of frequent interest • No well-designed randomized trials • What? • Don’t use prophylactic antibiotics for ventriculostomies • Antibiotic-impregnated ventriculostomy catheters? • Still lots of opinion on trach v. extubation for TBI patients with ↓ LOC
V. Deep Vein Thrombosis Prophylaxis RECOMMENDATIONS A. Level I There are insufficient data to support a Level I recommendation for this topic. B. Level II There are insufficient data to support Level II recommendation for this topic. C. Level III Graduated compression stockings or intermittent pneumatic compression (IPC) stockings are recommended, unless lower extremity injuries prevent their use. Use should be continued until patients are ambulatory. Low molecular weight heparin (LMWH) or low dose unfractionated heparin should be used in combination with mechanical prophylaxis. However, there is an increased risk for expansion of intracranial hemorrhage. There is insufficient evidence to support recommendations regarding the preferred agent, dose, or timing of pharmacologic prophylaxis for deep vein thrombosis (DVT).
DVT Prophylaxis • Why? • New topic; lots of concern over DVT/PE risk • Nobody knows what to do and studies are extremely limited • What? • You better do something • The old way of “no heparin for 14 days” is probably not going to cut it anymore • Trauma surgeons are pushing for prophylactic IVC filters
VI. Indications for Intracranial Pressure Monitoring RECOMMENDATIONS A. Level I There are insufficient data to support a treatment standard for this topic. B. Level II Intracranial pressure (ICP) should be monitored in all salvageable patients with a severe traumatic brain injury (TBI; Glasgow Coma Scale [GCS] score of 3–8 after resuscitation) and an abnormal computed tomography (CT) scan. An abnormal CT scan of the head is one that reveals hematomas, contusions, swelling, herniation, or compressed basal cisterns. C. Level III ICP monitoring is indicated in patients with severe TBI with a normal CT scan if two or more of the following features are noted at admission: age over 40 years, unilateral or bilateral motor posturing, or systolic blood pressure (BP) < 90 mm Hg.
Indications for ICP Monitoring • Why? • Talking Heads level of evidence – Same As It Ever Was • No well-designed randomized trials • Some naysayers cropping up • What? • Monitor ICP • Just do it and don’t overthink this one; it’s so critical to all other aspects of TBI care
VII. Intracranial Pressure Monitoring Technology CONCLUSIONS In the current state of technology, the ventricular catheter connected to an external strain gauge is the most accurate, low-cost, and reliable method of monitoring intracranial pressure (ICP). It also can be recalibrated in situ. ICP transduction via fiberoptic or micro strain gauge devices placed in ventricular catheters provide similar benefits, but at a higher cost. Parenchymal ICP monitors cannot be recalibrated during monitoring. Parenchimal ICP monitors, using micro strain pressure transducers, have negligible drift. The measurement drift is independent of the duration of monitoring. Subarachnoid, subdural, and epidural monitors (fluid coupled or pneumatic) are less accurate.
ICP Monitoring Technology • Why? • Ventricular catheters and fiberoptic parenchymal monitors are the only reliable monitors • What? • Use a ventriculostomy if possible because CSF can be drained as an ICP lowering intervention
VIII. Intracranial Pressure Thresholds RECOMMENDATIONS A. Level I There are insufficient data to support a Level I recommendation for this topic. B. Level II Treatment should be initiated with intracranial pressure (ICP) thresholds above 20 mm Hg. C. Level III A combination of ICP values, and clinical and brain CT findings, should be used to determine the need for treatment.
ICP Thresholds • Why? • Lot of observational data looking at populations of patients suggesting 20 mm Hg as a threshold for overall worsened outcomes • Reliance on the number alone is overly simplistic • What? • Keep ICP < 20 mm Hg • Use judgment • ICP is global number • ICP is really a compliance measure • Different ICP threshold for decompressive craniectomy patients? 15 mmHg? 10 mm Hg? • Treat your patient, not the number
IX. Cerebral Perfusion Thresholds RECOMMENDATIONS A. Level I There are insufficient data to support a Level I recommendation for this topic. B. Level II Aggressive attempts to maintain cerebral perfusion pressure (CPP) above 70 mm Hg with fluids and pressors should be avoided because of the risk of adult respiratory distress syndrome (ARDS). C. Level III CPP of < 50 mm Hg should be avoided. The CPP value to target lies within the range of 50–70 mm Hg. Patients with intact pressure autoregulation tolerate higher CPP values. Ancillary monitoring of cerebral parameters that include blood flow, oxygenation, or metabolism facilitates CPP management.
Cerebral Perfusion Thresholds • Why? • More is not better • Randomized trial showed 4-four increase in ARDS (Robertson CCM 1999) • Still lots of belief in the underlying concept of adequacy of cerebral perfusion pressure • Autoregulation is important • What? • Target a CPP > 60 mm Hg in most patients • Use advance neuromonitoring and autoregulation assessment to target individualized therapy
X. Brain Oxygen Monitoring and Thresholds RECOMMENDATIONS A. Level I There are insufficient data to support a Level I recommendation for this topic. B. Level II There are insufficient data to support a Level II recommendation for this topic. C. Level III Jugular venous saturation (<50%) or brain tissue oxygen tension (<15 mm Hg) are treatment thresholds. Jugular venous saturation or brain tissue oxygen monitoring measure cerebral oxygenation.
Brain Oxygen Monitoring and Thresholds • Why? • New topic; lots of people doing oxygen monitoring now • Nobody really knows what to do with the data • What? • Consider using PbtO2 and SjVO2 monitoring as part of regular care • Collect the data and participate in the randomized trials that are greatly needed
XI. Anesthetics, Analgesics, and Sedatives RECOMMENDATIONS A. Level I There are insufficient data to support a Level I recommendation for this topic. B. Level II Prophylactic administration of barbiturates to induce burst suppression EEG is not recommended. High-dose barbiturate administration is recommended to control elevated ICP refractory to maximum standard medical and surgical treatment. Hemodynamic stability is essential before and during barbiturate therapy. Propofol is recommended for the control of ICP, but not for improvement in mortality or 6 month outcome. High-dose propofol can produce significant morbidity.
Anesthetics, Analgesics, & Sedatives • Why? • It’s not just about barbs anymore • Propofol infusion syndrome is rare but real • Barbs can lower ICP, but also cause hemodynamic compromise • What? • Don’t use prophylactic barbs • Watch for metabolic acidosis and hypertriglyceridemia with propofol • Use more continuous EEG
XII. Nutrition RECOMMENDATIONS A. Level I There are insufficient data to support a Level I recommendation for this topic. B. Level II Patients should be fed to attain full caloric replacement by day 7 post-injury.
Nutrition • Why? • Nobody is going to do a randomized trial of starvation in TBI • Lots of interest in hyperglycemia treatment • What? • We are not feeding TBI patients fast enough • Feed patients ASAP • Enterally • Stomach v. post-pyloric? • Aggressive treatment of hyperglycemia • Consider higher threshold for TBI patients?
XIII. Antiseizure Prophylaxis RECOMMENDATIONS A. Level I There are insufficient data to support a Level I recommendation for this topic. B. Level II Prophylactic use of phenytoin or valproate is not recommended for preventing late posttraumatic seizures (PTS). Anticonvulsants are indicated to decrease the incidence of early PTS (within 7 days of injury). However, early PTS is not associated with worse outcomes.
Antiseizure Prophylaxis • Why? • Randomized trials show a decrease in early seizures with prophylactic anticonvulsants • What? • Use dilantin for 7 days? • Levetiracetam? • Does this even make sense or should we just skip the anticonvulsant? • Hypotension during IV loading? • Continuous EEG monitoring to target patients for treatment? • Long-term deleterious effects of anticonvulsants on neurological recovery?
XIV. Hyperventilation RECOMMENDATIONS A. Level I There are insufficient data to support a Level I recommendation for this topic. B. Level II Prophylactic hyperventilation (PaCO2 of 25 mm Hg or less) is not recommended. C. Level III Hyperventilation is recommended as a temporizing measure for the reduction of elevated intracranial pressure (ICP). Hyperventilation should be avoided during the first 24 hours after injury when cerebral blood flow (CBF) is often critically reduced. If hyperventilation is used, jugular venous oxygen saturation (SjO2) or brain tissue oxygen tension (PbrO2) measurements are recommended to monitor oxygen delivery.
Hyperventilation • Why? • Single randomized trial suggested that aggressive hyperventilation worsens outcome • Hyperventilation may lower CBF and create secondary ischemia • What? • Hyperventilate on the way to an acute intervention • Otherwise, don’t hyperventilate • Remember normoventilation is pH = 7.40 • Don’t obsess over PaCO2 days into hospitalization
XV. Steroids RECOMMENDATIONS A. Level I The use of steroids is not recommended for improving outcome or reducing intracranial pressure (ICP). In patients with moderate or severe traumatic brain injury (TBI), high-dose methylprednisolone is associated with increased mortality and is contraindicated.
Steroids • Why? • CRASH study showed increased mortality in glucocorticoid treated TBI patients (Lancet 2004) • What? • Don’t use steroids for TBI. Period. • What about in patients with combined TBI and spinal cord injury? Hm.
Severe TBI: BTF Guidelines • Guidelines • Are an important framework for care • Evolve with new evidence and approaches • Following the “Guidelines” • Is not something to be proud of • It’s lowest common denominator care • Need to be adapted to individual institutions with more specific • Standardized orders • Bedside “cheat sheets” • Educational tools • Institutional data collection and QA is very important