Rhabdomyolysis, Methamphetamine, Amphetamine and MDMA Use: Associated Factors and Risks.

OBJECTIVE: Rhabdomyolysis is associated with methamphetamine, amphetamine, and methylenedioxymethamphetamine (MA) use. The aim of this study was to determine the frequency, severity, and risk factors of rhabdomyolysis associated with MA use. Methods: We reviewed patients with an MA-positive toxicology screen with and without diagnosed rhabdomyolysis based on initial creatine kinase (CK) concentration over a period of 6 years. Demographics, vital signs, disposition, diagnoses, and laboratory results were recorded. Results: There were 7,319 patients with an MA-positive toxicology screen, of whom 957 (13%) were screened for rhabdomyolysis and included in the study. The majority were male, White, and middle-aged and smoked tobacco. Psychiatric (34%), neurological (15%), and trauma (13%) were the most common discharge diagnostic groups. The majority (55%) were admitted, and 8% were discharged to an inpatient psychiatric facility. Concomitant substance use included ethanol (10%) and cocaine (8%), and 190 (20%) had rhabdomyolysis with median (interquartile range) CK of 2,610 (1,530-6,212) U/L and range 1,020 to 98,172 U/L. There was significant difference in renal function between the rhabdomyolysis and non-rhabdomyolysis patients. Other differences included gender and troponin I concentration. A higher proportion of patients screening positive for both MA and cocaine use experienced rhabdomyolysis. Multiple logistic regression analysis revealed elevated troponin I, blood urea nitrogen, and/or creatinine concentration and male gender to be significant factors associated with rhabdomyolysis. Conclusions: The frequency of rhabdomyolysis in patients screening positive for MA was 20%. Factors associated with rhabdomyolysis in MA-positive patients included elevated troponin, blood urea nitrogen, creatinine concentration, and male gender. Clinicians caring for patients who screen positive for MA should also consider concomitant rhabdomyolysis, especially if renal/cardiac laboratory tests are abnormal and even if there is no history of injury, agitation, or physical restraint.

Methamphetamine use and heart failure: Prevalence, risk factors, and predictors.

OBJECTIVES: To compare methamphetamine users who develop heart failure to those who do not and determine predictors. METHODS: Patients presenting over a two-year period testing positive for methamphetamine on their toxicology screen were included. Demographics, vital signs, echocardiography and labs were compared between patients with normal versus abnormal B-type natriuretic peptide (BNP). RESULTS: 4407 were positive for methamphetamine, 714 were screened for heart failure, and 450 (63%) had abnormal BNP. The prevalence of abnormal BNP in methamphetamine-positive patients was 10.2% versus 6.7% for those who were negative or not tested. For methamphetamine-positive patients, there was a tendency for higher age and male gender with abnormal BNP. A higher proportion of Whites and former smokers had abnormal BNP and higher heart and respiratory rates. Echocardiography revealed disparate proportions for normal left ventricular ejection fraction (LVEF) and severe dysfunction (LVEF <30%), LV diastolic function, biventricular dimensions, and pulmonary arterial pressures between subgroups. For methamphetamine-positive patients with abnormal BNP, creatinine was significantly higher, but not Troponin I. Logistic regression analysis revealed predictors of abnormal BNP and LVEF <30% in methamphetamine-positive patients, which included age, race, smoking history, elevated creatinine, and respiratory rate. CONCLUSION: Methamphetamine-positive patients have a significantly higher prevalence of heart failure than the general emergency department population who are methamphetamine-negative or not tested. The methamphetamine-positive subgroup who develop heart failure tend to be male, older, White, former smokers, and have higher creatinine, heart and respiratory rates. This subgroup also has greater biventricular dysfunction, dimensions, and higher pulmonary arterial pressures.

Venous ultrasound testing for suspected thrombosis: incidence of significant non-thrombotic findings.

Duplex ultrasound (US) is used to "rule out" deep venous thrombosis (DVT), but can also diagnose other causes of leg pain or swelling in Emergency Department (ED) patients. Recent literature suggests that US imaging is unnecessary among patients with low or moderate clinical probability of DVT with a normal D-dimer. We attempted to determine the incidence of clinically important incidental findings detected using venous US imaging in patients with suspected lower extremity DVT. We conducted a retrospective chart review of all ultrasounds performed by the non-invasive vascular laboratory on ED patients > 18 years old. Results were classified: normal, DVT, or incidental finding. The latter were classified as clinically significant major findings if the diagnosis led to immediate and specific treatment to prevent morbidity, or clinically significant minor findings. A total of 484 US studies were reviewed; 179 were excluded (arterial studies, penetrating trauma, upper extremity US). Findings among 305 studies were: 238 (78%) normal, 28 (9%) DVT, and 39 (12%) incidental findings. Among 39 incidental findings, 10 were clinically significant major findings and 29 clinically significant minor findings. Clinically significant major findings included: pseudoaneurysm, arterial occlusive disease, vascular graft complication, compartment syndrome, and tumor. Among 38 abnormal US studies that required immediate treatment, DVT comprised 74% (95% confidence interval 59%-85%) and important major incidental findings 26% (95% confidence interval 14%-41%). Among ED patients who underwent US to evaluate leg pain and swelling, 26% of positive studies showed clinically important findings other than DVT. Further research is needed to determine if D-dimer plus a clinical probability tool will include or exclude the patients with clinically significant major findings.

Assessing the need for functional diagnostic testing in low-risk women with chest pain.

OBJECTIVE: The objective of this study was to assess the need for functional diagnostic testing to identify coronary artery disease (CAD) in women presenting with chest pain and deemed at low risk in a chest pain evaluation unit (CPEU) setting. METHODS: Low-risk women evaluated in a CPEU were defined as having < or =1 intermediate determinant of CAD (hypertension, tobacco use, or hypercholesterolemia) or < or =2 minor determinants (age, obesity, sedentary lifestyle, or family history of CAD). Patients were followed for 30 days for the occurrence of CAD, defined as a positive stress imaging study, significant CAD on angiography, myocardial revascularization, myocardial infarction (MI), or cardiac death. RESULTS: Of 1355 consecutive women evaluated, 527 (39%) were classified as low risk. The rate of CAD in the low-risk group was 1.3% of which there were no coronary events. CONCLUSION: Women admitted to a CPEU and identified as low risk are at very low risk for CAD.

Cholesterol screening in an ED-based chest pain unit.

To evaluate the prevalence of dyslipidemia in patients who are evaluated in a chest pain evaluation unit (CPEU) a prospective study of all patients admitted to our CPEU from January 1 to December 31, 1999 was conducted. Serum total cholesterol (TC) and high density lipoprotein (HDL) levels were obtained unless prior levels were known or at the discretion of the attending physician. Both TC and HDL were tested in 606 (59%) patients. Abnormal lipid levels were reported in 306 (50%) patients. Of these, 86 had both abnormal TC and HDL. Isolated low HDL levels were found in 60 of the patients and TC alone was abnormal in 160. Of the 246 patients with abnormal TC, 169 (69%) had borderline high levels (200-239 mg/dL) and 77 (31%) had high levels (>or=240 mg/dL). Our study shows a high prevalence of abnormal lipid levels in patients, as identified by a screening protocol in our CPEU.