Paul Wohlt

Venous Thromboembolism in Critically Ill Medical Patients Receiving Chemoprophylaxis: A Focus on Obesity and Other Risk Factors.

Purpose: To compare the incidence of 90-day venous thromboembolism (VTE) in obese critically ill medical patients receiving VTE chemoprophylaxis with nonobese patients of similar illness severity. We also identified other VTE risk factors. Methods: Eligible patients spent ≥24 hours in an intensive care unit between November 2007 and November 2013 and received VTE chemoprophylaxis within 48 hours of admission. The primary outcome was 90-day VTE. Results: A total of 11 111 patients were evaluated, of which 1732 obese and 1831 nonobese patients were enrolled with mean BMIs of 38.9 ± 9.2 kg/m2 and 24.5 ± 3.1 kg/m2 and mean Acute Physiology and Chronic Health Evaluation II scores of 28.4 ± 11.8 and 26.6 ± 11.7, respectively. The rate of 90-day VTE for the total cohort, obese, and nonobese patients was 6.5%, 7.5%, and 5.5%, respectively. Obese patients were more likely to develop VTE compared with nonobese patients (odds ratio [OR]: 1.41; 95% confidence interval [CI]: 1.03 -1.93). Other risk factors significantly associated with 90-day VTE included prior VTE (OR: 3.93; 95% CI: 1.83-8.48), trauma with surgery in the previous 30 days (OR: 3.70; 95% CI: 1.39-9.86), central venous catheters (OR: 2.64; 95% CI: 1.87-3.72), surgery within 90 days (OR: 2.40; 95% CI: 1.61-3.58), mechanical ventilation (OR: 1.94; 95% CI: 1.39-2.71), male sex (OR: 1.55; 95% CI: 1.13-2.14), and increasing age using 1-year increments (OR: 1.02; 95% CI: 1.01 -1.03). Conclusions: The rate of VTE in critically ill medical patients remains high despite standard chemoprophylaxis. Obesity is among 8 risk factors independently associated with 90-day VTE.

541: RISK OF RESISTANT MICROORGANISMS WITH PROLONGED ANTIBIOTIC PROPHYLAXIS FOR INTRACRANIAL DEVICES

Crit Care Med 2015 • Volume 43 • Number 12 (Suppl.) between groups. Results: 35 patients were enrolled through the first four mo of study (August-November, 2014), of whom 21 (60%) were men. Mean (SD) age was 48.2 (23) yr. Fourteen patients (40%) had severe TBI and twenty (57%) had mild TBI. Mean pre-hospital GCS was 10.4 and mean APACHE III score was 42.3. Five (14%) had history of coronary artery disease, and none had pre-existing heart failure. Five patients (14%) developed cardiac dysfunction after TBI. Three patients had mild reduction in the left ventricular ejection fraction (LVEF) (45–54%), and two had moderately reduced LVEF (30–44%). Regional wall motion abnormalities were identified in three patients. There were no statistically significant differences in duration of mechanical ventilation, hospital and ICU length of stay, and mortality between patients who developed cardiac dysfunction compared to patients who did not develop cardiac dysfunction, but comparison was limited by small sample size. Conclusions: Cardiac dysfunction occurs after a TBI but the incidence appears to be lower than the published literature.

1173: QTC PROLONGATION PROGRESSING TO TORSADE DE POINTES SECONDARY TO IBOGAINE INGESTION

Learning Objectives: Ibogaine is a naturally occurring alkaloid with hallucinogenic and psychedelic effects. It is classified as a schedule I controlled substance in the U.S., but is available in several countries and may also be purchased through the internet. It is promoted as an antiaddiction medication, but safety concerns include the risk of cardiac arrhythmias; the mechanism of which is unclear but may involve inhibition of hERG potassium or sodium channels. This case involved a 40 year old female with a history of cocaine and heroin abuse taking ibogaine to help decrease drug cravings. EMS was called when the patient was found unresponsive at home. Naloxone 1 mg was administered en route resulting in slight arousal and agitation. Upon arrival to the emergency department, the patient had continued agitation and received lorazepam 2 mg IV and haloperidol 5 mg IV. Shortly after, the patient became bradycardic and developed an episode of nonsustained ventricular tachycardia (VT) which selfresolved. A brief generalized tonic-clonic seizure ensued and the patient was subsequently intubated. Multifocal premature ventricular contractions (PVCs) were observed on telemetry and the patient was given 2 g of IV magnesium sulfate with resolution of PVCs. EKG results revealed a prolonged QTc interval of 599 msec and initial labs had notable derangements of serum magnesium (1.1 mg/ dL) and potassium (3.4 mEq/L). 10 hours after admission, the patient went into cardiac arrest due to polymorphic VT consistent with torsade de pointes. Chest compressions were performed with ROSC with sinus rhythm. An EKG revealed a prolonged QTc interval of 601 msec and 2 g of IV magnesium sulfate was administered. Over the 6-day admission, the patient’s QTc trended downward with no further cardiac issues. The etiology of torsade de pointes is attributed to ibogaine use, concomitant haloperidol administration, and electrolyte abnormalities. This case correlates long-QT syndrome and torsade de pointes with the use of ibogaine, a compound being actively evaluated for its potential to treat substance addiction.