Table 1: Predictors of Lidocaine Use Lidocaine and Fentanyl Use Prior to Endotracheal Intubation in Patients with Traumatic Brain Injury Jaymin Patel B.S.1, M. Austin Johnson M.D.2, James Holmes M.D.2 1University of California, Davis, School of Medicine, Sacramento, CA; 2University of California, Davis, Department of Emergency Medicine, Sacramento, CA INTRODUCTION MATERIALS AND METHODS RESULTS Table 1: Predictors of Lidocaine Use In the United States, traumatic brain injury (TBI) accounted for 2.5 million emergency department visits, hospitalizations and deaths in 2010 according to the CDC. Airway management in these patients is especially important because hypoxia has been associated with poor neurologic outcome (McHugh et al). In addition, direct laryngoscopy causes a reflex sympathetic response which increase the systemic mean arterial pressure (MAP), which may act to worsen neurological injury through increasing the cerebral perfusion pressure (CPP), which results in increased intracranial pressure (ICP) (Figure 1). Therefore there is a direct causal link between the sympathetic response caused by direct laryngoscopy to increased ICP. Increased ICP is thought to lead to secondary brain injury in patients with TBI due to effects of pressure and swelling within the cranial vault. Traumatic brain injury patients are not only more susceptible to hemodynamic changes due to impaired autoregulation (Figure 1), but also have been shown to have hypertensive responses to advanced airway procedures (Enevoldsen et al; Perkins et al). Pretreatment with fentanyl and/or lidocaine before rapid sequence intubation (RSI) has been utilized as a way to combat this potentially harmful scenario. In addition, there is limited evidence addressing the effectiveness of pretreatment with either lidocaine or fentanyl in improving neurologic outcome in patients with TBI. A 2001 review article identified 6 previous studies looking at the link between use of lidocaine pretreatment and neurological outcome and concluded that there was no evidence to support the use of lidocaine (Robinson et al). Utilization rates of lidocaine and fentanyl also remain inconsistent in patients with TBI (Kuzak et al). Therefore there seems to be no clear consensus about using pretreatment before RSI in patients with known traumatic brain injury and adherence to current recommendations is unknown.   In this retrospective cohort study, using accepted and structured chart abstraction methodology, we examined the records of adults who presented to the emergency department of the University of California, Davis Medical Center with blunt head trauma undergoing emergency department intubation through RSI. The study population included 100 patients who met all inclusion and exclusion criteria. We included patients between the ages of 18 to 100 who presented to the ED between 10/1/2008 to 1/1/2014 with blunt head trauma and an abbreviated injury score (AIS) head from 3 through 5. Patients transferred from outside institutions, who had penetrating-type traumatic brain injury, were discharged from the ED, or who presented in traumatic arrest were excluded. Through chart review age, gender, injury severity score, AIS-head and initial vital signs were obtained. All of the patient information was stripped of identifying data. Usage rates of lidocaine and fentanyl as pretreatment before RSI were calculated. In a subset of patients who were treated by physicians who varied in their use of premedication before RSI, multivariable logistic regression was used to estimate characteristics associated with use of premedications. Previously hypothesized markers of injury severity were included as covariates during model development. Out of 100 patients, 33 (33%, 95%CI 5-43%) received lidocaine, 1 (1%, 95%CI 0-5%) received fentanyl, and 1 (1%, 95%CI 0-5%) received both lidocaine and fentanyl. No significant difference was identified in the mean age (42.1 vs. 43.7), gender (Female no lidocaine 22.4%, Female with lidocaine 30.3%), injury severity score (29.6 vs. 30.8) or AIS-head score (4.3 vs. 4.5) in patients who did and did not receive pretreatment with lidocaine. No independent predictors of lidocaine use were identified. In the subset of patients who were treated by physicians who varied in their use of pretreatment medications, there were also no independent predictors for lidocaine use (Table 1). With respect to use of lidocaine pretreatment, arrival GCS had an odds ratio of 0.99 (p = 0.91), arrival pulse 1.00 (p = 0.59), arrival hypotension 0.32 (p = 0.32) and AIS-Head 1.38 (p = 0.30). Inter-rater reliability for data abstraction was excellent with kappa scores ranging from 0.89-1.0.   Odds Ratio 95CI p Arrival GCS 0.99 0.82-1.19 0.91 Arrival Pulse 1 0.98-1.01 0.59 Arrival Hypotension 0.32 0.03-2.99 AIS-Head 1.38 0.75-2.55 0.3 REFERENCES Enevoldsen EM, Jensen FT. Autoregulation and CO2 responses of cerebral blood flow in patients with acute severe head injury.J Neurosurg. 1978 May;48(5):689-703. Kuzak N, Harrison DW, Zed PJ. Use of lidocaine and fentanyl premedication for neuroprotective rapid sequence intubation in the emergency department. CJEM. 2006 Mar;8(2):80-4. Robinson N, Clancy M. In patients with head injury undergoing rapid sequence intubation, does pretreatment with intravenous lignocaine/lidocaine lead to an improved neurological outcome? A review of the literature. Emerg Med J. 2001 Nov;18(6):453-7. Review. Perkins ZB, Wittenberg MD, Nevin D, Lockey DJ, O'Brien B. The relationship between head injury severity and hemodynamic response to tracheal intubation. J Trauma Acute Care Surg. 2013 Apr;74(4):1074-80. doi: 10.1097/TA.0b013e3182827305. CONCLUSION This study reveals that lidocaine is uncommonly used and fentanyl is rarely used as pretreatment medications during ED RSI of patients with TBI. These findings signify that there is no consensus about the use of lidocaine as premedication, but that the use of fentanyl is generally avoided. In this population if a patient with TBI demands emergent airway management, intubation would more than likely take place without premedication. Focusing on this study, perhaps the more noteworthy fact is that the lidocaine was inconsistently used by providers who varied in their use of premedication. In the subset of 33 patients who were treated by these providers, there were no independent predictors of lidocaine use, which signifies that either there is random variability in the use of premedication or the providers relied about factor(s) that were not considered in this study. These findings suggest substantial variability in the use of lidocaine in patients with TBI who require emergent endotracheal intubation. For further study, this type of investigation can be repeated in different hospitals to examine if the variability is present in other institutions or practices. CONTACT Jaymin Patel UC Davis School of Medicine jjpatel@ucdavis.edu M.Austin Johnson UC Davis Department of Emergency medicine mausjohnson@ucdavis.edu OBJECTIVES We hypothesized that lidocaine and fentanyl are routinely used prior to intubation in patients with blunt head trauma and that patients with more severe traumatic brain injuries would receive pretreatment more often. Figure 1: Increased ICP as a physiological response to TBI and intubation