Sean O. Henderson

Use of Heliox-Driven Nebulizer Therapy in the Treatment of Acute Asthma

STUDY OBJECTIVE To compare the effectiveness of a helium-oxygen mixture with that of oxygen alone as an aerosolizing gas for beta-agonist therapy in patients with mild to moderate exacerbation of asthma. METHODS A prospective, single-blinded study was performed in an urban teaching hospital over a period of 5 months. A convenience sample of 205 patients with mild to moderate exacerbation of asthma were enrolled. The participants were randomly assigned to 1 of 2 groups. The first group received 3 doses of albuterol, 5.0 mg aerosolized in 10 L/min of oxygen, 15 minutes apart. The second group received 3 doses of albuterol, 5.0 mg aerosolized in 10 L/min of a 70:30 helium-oxygen mixture (heliox), 15 minutes apart. Peak expiratory flow rate (PEFR), forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV1 ) were measured before and after each treatment. Only PEFR and FEV1 were used in data analysis. RESULTS Although both the heliox and the oxygen group showed significant improvement in PEFR from baseline after 45 minutes (72% and 70%, respectively), the difference between the 2 groups was clinically and statistically insignificant (P =.56). Similar findings were observed for FEV1. There was no difference in rate of admission or rate of complications between the 2 groups. CONCLUSION Despite its ability to decrease the turbulent flow in airways and to reach distal pulmonary tissues, heliox had no clinically significant advantage over standard therapy in the treatment of mild to moderate asthma. Further large-scale studies are necessary to determine the clinical efficacy of heliox in this setting.

Randomized Clinical Trial of an Emergency Department Observation Syncope Protocol Versus Routine Inpatient Admission

STUDY OBJECTIVE Older adults are frequently hospitalized from the emergency department (ED) after an episode of unexplained syncope. Current admission patterns are costly, with little evidence of benefit. We hypothesize that an ED observation syncope protocol will reduce resource use without adversely affecting patient-oriented outcomes. METHODS This randomized trial at 5 EDs compared an ED observation syncope protocol to inpatient admission for intermediate-risk adults (≥50 years) presenting with syncope or near syncope. Primary outcomes included inpatient admission rate and length of stay. Secondary outcomes included 30-day and 6-month serious outcomes after hospital discharge, index and 30-day hospital costs, 30-day quality-of-life scores, and 30-day patient satisfaction. RESULTS Study staff randomized 124 patients. Observation resulted in a lower inpatient admission rate (15% versus 92%; 95% confidence interval [CI] difference -88% to -66%) and shorter hospital length of stay (29 versus 47 hours; 95% CI difference -28 to -8). Serious outcome rates after hospital discharge were similar for observation versus admission at 30 days (3% versus 0%; 95% CI difference -1% to 8%) and 6 months (8% versus 10%; 95% CI difference -13% to 9%). Index hospital costs in the observation group were

Multiple Polymorphisms in the Renin-Angiotensin-Aldosterone System (ACE, CYP11B2, AGTR1) and Their Contribution to Hypertension in African Americans and Latinos in the Multiethnic Cohort

629 (95% CI difference -

Common Presentations of Amebic Liver Abscess

1,376 to -

Established Risk Factors Account for Most of the Racial Differences in Cardiovascular Disease Mortality

56) lower than in the admission group. There were no differences in 30-day quality-of-life scores or in patient satisfaction. CONCLUSION An ED observation syncope protocol reduced the primary outcomes of admission rate and hospital length of stay. Analyses of secondary outcomes suggest reduction in index hospital costs, with no difference in safety events, quality of life, or patient satisfaction. Our findings suggest that an ED observation syncope protocol can be replicated and safely reduce resource use.

The presentation of tetanus in an emergency department

Objective:When compared with other U.S. populations, African Americans have excess hypertension. Genetic variants in elements of the renin-angiotensin-aldosterone system (RAAS), namely the angiotensin-converting enzyme (ACE), aldosterone synthase (CYP11B2), and angiotensin II type 1 receptor (AGTR1) genes, have been associated with risk of hypertension in some populations. Methods:We genotyped the D/I polymorphism in the ACE gene, the C(-344)T polymorphism in the CYP11B2 gene, and the C(-535)T polymorphism in the AGTR1 gene among African American and Latino members of the Multiethnic Cohort Study (MEC) to determine their association with hypertension. Results:We observed no significant increase in the risk of hypertension for either African Americans or Latinos homozygous or heterozygous for the D allele of the ACE gene. Among African Americans we observed carriers of the (-344)T allele of CYP11B2 to be at increased risk of hypertension (versus CC genotype: TC genotype, OR = 1.66 [95% CI: 1.01–2.72]; TT genotype, OR = 1.74 [95% CI: 1.07–2.82]). There was also an increase in risk of hypertension associated with the AGTR1 T allele for African Americans (versus CC genotype: TC genotype, OR = 2.62 [95% CI: 1.46–4.72]; TT genotype, OR = 2.67 [95% CI: 1.51–4.74]). The associations observed with CYP11B2 and AGTR1 genotypes were not observed among Latinos. Conclusion:These data suggest that the (-535)T allele of AGTR1 and (-344)T allele of CYP11B2 may increase hypertension risk among African Americans but not among Latinos. Characterization of the linkage disequilibrium and haplotype patterns in the RAAS pathway genes will be crucial to understanding differences in hypertension susceptibility in these ethnic populations.

Three common presentations of ascariasis infection in an urban Emergency Department

STUDY OBJECTIVE The most common extraintestinal manifestation of Entamoeba histolytica, the agent of amebiasis, is a hepatic abscess. This infection is common throughout the world and can be associated with life-threatening consequences. Given the often nonspecific nature of the complaints related to an amebic abscess, a retrospective review of patients with confirmed disease was done to recognize the most common patterns of presentation. METHODS A retrospective case series was conducted of all patients with confirmed amebic liver abscess over a 5-year period. All available emergency department and inpatient records were reviewed. Age, sex, country of origin, chief complaint (including duration), vital signs, and physical and laboratory findings were recorded. The use of ultrasonography, computed tomography scan, chest radiograph, and serum antibodies was noted, as well as the final ED diagnosis. RESULTS Seventy-five patients were reviewed; mean patient age was 35.5 years, 80% were male, and Mexico was the country of origin for 64%. The most common complaint was fever (77%), followed by abdominal pain (72%), which was most often located in the right upper quadrant. Cough (16%), chest pain (19%), and chest radiographic abnormalities (57%) were also common. The majority of patients (69%) had symptoms for less than 13 days. The WBC count was the most consistent laboratory abnormality (83%), whereas the liver aminotransferase, alkaline phosphatase, and bilirubin levels were often normal. Most patients received their diagnoses on the basis of ultrasonography (85%), followed by a confirmatory serum antibody titer (88%). The diagnosis of amebic liver abscess was correctly made in the ED in 31.5% of the patients, with the most common misdiagnoses being cholecystitis (16.4%), hepatitis (12.3%), and pneumonia (9.6%). CONCLUSION Patients with amebic liver abscess do present to EDs in the southwestern United States, especially in areas with a high immigrant population from endemic areas. Patients with complaints of fever and right upper quadrant abdominal pain, especially men of Hispanic origin, warrant a high degree of vigilance. Whereas most laboratory studies are unhelpful, the diagnosis can often be made in the ED by means of a bedside ultrasonographic test. Treatment should be initiated with metronidazole with disposition to an inpatient medical service.

Anticoagulation Drug Therapy: A Review

Background Cardiovascular disease (CVD) mortality varies across racial and ethnic groups in the U.S., and the extent that known risk factors can explain the differences has not been extensively explored. Methods We examined the risk of dying from acute myocardial infarction (AMI) and other heart disease (OHD) among 139,406 African-American (AA), Native Hawaiian (NH), Japanese-American (JA), Latino and White men and women initially free from cardiovascular disease followed prospectively between 1993–1996 and 2003 in the Multiethnic Cohort Study (MEC). During this period, 946 deaths from AMI and 2,323 deaths from OHD were observed. Relative risks of AMI and OHD mortality were calculated accounting for established CVD risk factors: body mass index (BMI), hypertension, diabetes, smoking, alcohol consumption, amount of vigorous physical activity, educational level, diet and, for women, type and age at menopause and hormone replacement therapy (HRT) use. Results Established CVD risk factors explained much of the observed racial and ethnic differences in risk of AMI and OHD mortality. After adjustment, NH men and women had greater risks of OHD than Whites (69% excess, P<0.001 and 62% excess, P = 0.003, respectively), and AA women had greater risks of AMI (48% excess, P = 0.01) and OHD (35% excess, P = 0.007). JA men had lower risks of AMI (51% deficit, P<0.001) and OHD (27% deficit, P = 0.001), as did JA women (AMI, 37% deficit, P = 0.03; OHD, 40% deficit, P = 0.001). Latinos had underlying lower risk of AMI death (26% deficit in men and 35% in women, P = 0.03). Conclusion Known risk factors explain the majority of racial and ethnic differences in mortality due to AMI and OHD. The unexplained excess in NH and AA and the deficits in JA suggest the presence of unmeasured determinants for cardiovascular mortality that are distributed unequally across these populations.

Necrotizing fasciitis due to appendicitis

Traditionally, the literature has described a certain population as at risk for tetanus infection. We reviewed the demographics, clinical presentation, laboratory findings, management, and outcome of all patients who presented to our emergency department (ED) with tetanus in the last 10 years and compared our experience with this classic literature. We performed a retrospective case series review at a large, inner-city medical center; 11 cases of tetanus were identified from 1986 to 1997. Nine male and two female patients were identified with an average age of 45 years. All had an acute injury to the skin, and most (82%) reported having no history of recent immunization. The most common recorded symptoms were trismus and rigidity in the abdomen, neck, back, or extremities. There was only one misdiagnosis in the ED. Three patients died in the hospital, while the other eight were discharged either home or to a rehabilitation facility. In contrast to the classic literature, we found that tetanus in our inner city ED presented in recent immigrants, particularly younger men, over half of whom had received no childhood immunization. Laboratory results and cultures are of little diagnostic value, so timely recognition of the clinical presentation is important.

End-Tidal CO 2 as a Predictor of Survival in Out-of-Hospital Cardiac Arrest

In the United States, approximately 4 million people per year are infected with Ascaris lumbricoides. We reviewed the common presentations of complications of Ascariasis infection in the Emergency Department (ED) and the diagnostic tools and treatment available. This was a retrospective case review conducted on all patients diagnosed with Ascariasis (using ICD-9 codes) over a 6-year period at Los Angeles County and University of Southern California Medical Center. Three patients with distinct complications secondary to Ascariasis were chosen, and all ED and inpatient records were reviewed. The patients age, sex, race, presenting symptoms, data, outcome, and ED course and diagnosis were recorded. The three cases included a periappendiceal abscess, Loefflers syndrome, and biliary colic/choledocholithiasis. The first patient underwent a computed tomography-guided drainage of the abscess. The second patient received supportive care and antibiotic therapy secondary to a superimposed bacterial pneumonia. The third patient underwent endoscopic retrograde cholangiopancreatography with sphincterotomy. All three patients had a stool ova and parasites positive for A. lumbricoides, and all received a 3-day course of mebendazole. Symptomatic cases of Ascariasis may present to EDs in the United States. Important diagnostic tools for the ED include chest X-ray, X-ray of the kidney-ureter-bladder and ultrasonography. Single-dose medications given in the ED are very effective in eradicating A. lumbricoides infection, thus avoiding hospitalization.