underwent an endovascular therapeutic procedure. His postintervention progress was uneventful.

Because US is portable, rapid, noninvasive, irradiation free, easy to perform, and can be used repeatedly, it is the initial examination performed. In stable critically ill patients, negative or positive US is followed by a CT scan or CT angiography. In hemodynamically unstable patients, US is followed by an emergency Exploratory laparotomy or an angiographic procedure [4]. However, the limits of this technique must be recognized. The study by Sirlin et al [2] showed that among 3679 patients with blunt abdominal trauma and negative screening US scans, 99.9% were true negative, and 36 patients were false negative, including 24 patients who were nonsurgical. The 6 most common missed injuries included RH (n = 13) and injuries to the spleen (n = 10), liver (n = 9), kidney (n = 8), adrenal gland (n = 8), and small bowel (n = 7) [2]. Moreover, although our examples show important RH localized in the flanks (zone 2), US seems to fail to detect RH in the central- median (Zone 1) or pelvic (Zone 3) area [5].

Ultrasonography can be of use in triage and initial diagnostic assessment because it reduces the time needed to prepare for an angiographic procedure or laparotomy. Despite the high clinical value of negative-screening US scans, this technique has a limitation, which is the detection of parenchymal abnormalities or RH. Nevertheless, their imag- ing is possible, and the technique must be taught to improve the management of critically ill patients and to gain time.

Hichem Chenaitia MD Department of Emergency Medicine and Radiology Clavary General Hospital, Grasse, France

E-mail address: [email protected]

Khaled Abrous MD Fabrice Louis MD

Department of Emergency Medicine Clavary General Hospital, Grasse, France

Christine Aime MD

Department of Radiology Clavary General Hospital, Grasse, France

Tomislav Petrovic MD Prehospital Emergency Medical Services Avicenne Hospital, Bobigny, France

WINFOCUS (World Interactive Network Focused On

Critical UltraSound) Group France doi:10.1016/j.ajem.2011.04.005

References

1. Chan YC, Morales JP, Reidy JF, Taylor PR. Management of spontaneous and iatrogenic retroperitoneal haemorrhage: conservative

management, endovascular intervention or open surgery? Int J Clin Pract 2008;62(10):1604-13.

1. Sirlin CB, Brown MA, Andrade-Barreto OA, Deutsch R, Fortlage DA, Hoyt DB, Casola G. Blunt abdominal trauma: clinical value of negative screening US scans. Radiology 2004;230(3):661-8.
2. Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically ill. Emerg Med Clin North Am 2010;28(1):29-56.
3. Radwan MM, Abu-Zidan FM. Focussed Assessment Sonograph Trauma (FAST) and CT scan in blunt abdominal trauma: surgeon’s perspective. Afr Health Sci 2006;6(3):187-90.
4. Feliciano DV. Management of traumatic Retroperitoneal hematoma. Ann Surg 1990;211(2):109-23.

Abnormal urinalysis finding triggered antibiotic prescription for asymptomatic bacteriuria in the ED^?,??

To the Editor,

Differentiation between Asymptomatic bacteriuria and symptomatic urinary tract infection (SUTI) is important for treatment guidance because antibiotic therapy for AB offers benefit to only pregnant women and patients undergoing urologic procedures [1,2]. Unnecessary antibiotic prescription for AB may put patients at risk for development of antibiotic resistance and adverse reactions [1-3]. As previously described by our study in regard to the increased antibiotic resistance rates among SUTI patients presenting to our emergency department (ED) [4], unnecessary antibiotic treatment for AB was of concern. We conducted this study to evaluate the practice of urine testing and management of AB in the ED setting.

All patients 12 years or older who were evaluated at the Rush University Medical Center ED from August 1, 2008, to March 31, 2009, and had positive urine cultures (bacterial growth >=10⁴ colony-forming unit/mL) were eligible for the study [3,5]. Patients were retrospectively identified by daily review of urine specimens sent to the microbiology laboratory. Electronic medical record review was performed for demographics, comorbidities, reasons for performing Urine tests, diagnoses of AB vs SUTI based on guidelines from the Infectious Disease Society of America [1], and treatments. Health care exposures were defined as having chronic indwelling urinary catheters, staying in the hospital for at least 48 hours, being nursing home or long-term care facility residents, attending regular hemodialysis clinics, and having urologic procedures within the past 3 months [4,6]. The study was approved by the Rush University Medical Center Institutional Review Board. All analyses were performed using SPSS, version 15.0 (SPSS, Chicago, IL).

^? Conflict of Interest: Dr K Singh is on the Visiting Speakers Board for Wyeth and is a Scientific Advisory Board Member of Quidel Corporation. Drs S Vasoo, T Khawcharoenporn, and E Ward have no conflicts of interest to declare. Financial Support: None reported.

^?? These data were present in part at the Infectious Diseases Society of

America 48th Annual Meeting 2010, Vancouver, Canada.

Categorical variables were compared using the Pearson ?2 or Fisher exact test, as appropriate. Continuous variables were compared using Mann-Whitney U test. Risk factors associated with antibiotic treatment for AB were determined. There were 676 patients with positive urine cultures; 184 (27%) had AB and 492 (73%) had SUTI. None of 184 AB patients were pregnant or planned to undergo urologic procedures. Patients with AB were significantly older (P b

.001), more likely to be white (P b .001), have recent health care exposure (P b .001), and have diabetes mellitus (P =

.006) than those with SUTI. The demographic and clinical characteristics of AB patients are shown in Table 1. The most common bacteria recovered from AB were Escherichia coli (47%), Enterococcus spp (18%), Klebsiella spp (10%), and Proteus spp (10%). Reasons for sending Urine dipstick tests and urine cultures among AB patients included gastrointestinal-related abdominal pain (28 [15%]), fever

(24 [13%]), altered mental status (13 [7%]), low back pain

(4 [2%]), trauma (3 [1%]), and discharge from genital tract

(2 [1%]). However, most of the patients (110 [60%]) had urine tests ordered without a specified indication.

Table 1 Comparison of characteristics of 184 patients with AB with and without antibiotic treatment

Of 184 AB patients, 37 (20%) were treated with antibiotics. Almost all patients (89%) received antibiotic therapy before availability of positive urine culture results. Levofloxacin was the most common prescribed antibiotic (43%), followed by nitrofurantoin (13%) and ceftriaxone (10%). Positive urine nitrite test and urine leukocyte of

10 cells per high-power field (HPF) or greater were significantly associated with antibiotic treatment for AB in both univariate and multivariate analyses (Table 1). Patients who received antibiotic treatment for AB were more likely to have urine tests without a specified indication than those who did not receive antibiotics (76% vs 56%, P = .03).

Our study findings demonstrated a high rate of AB, 27%. Among AB cases, 60% had urine tests sent without a specified indication. This high rate of urine testing could be explained by the tendency for empiric investigation, which is common in ED settings. However, a positive urine testing result triggered the prescription of antibiotics and may account for the high rates of antibiotic therapy for AB.

Factors associated with antibiotic treatment for AB in hospitalized patients from previous studies included

Characteristics	All (N = 184)		AB with antibiotic treatment (n = 37)	AB not treated (n = 147)		P a	Adjusted odds ratio (95% confidence interval)	P b
Age
Median (range)	59 y	(40-73 y)	57 y (37-72 y)	59 y	(43-74 y)	.78	-	-
Age >=50 y	118	(64)	21 (57)	97	(66)	.30	-	-
Age >=80 y	29	(16)	7 (19)	22	(15)	.56	-	-
Female sex	140	(76)	31 (84)	109	(74)	.22	2.50 (0.84-7.40)	.10
Ethnicity
African American	83	(45)	15 (41)	68	(46)	.53	-	-
White	23	(13)	16 (43)	54	(37)	.47	-	-
Hispanic	70	(38)	4 (11)	19	(13)	1.00	-	-
Asian	6	(3)	1 (3)	5	(3)	1.00	-	-
Other	2	(1)	1 (3)	1	(1)	.36	-	-
Health care exposure	91	(50)	19 (51)	72	(49)	.80	-	-
Nursing home/LTAC resident	16	(9)	3 (8)	13	(9)	1.00	-	-
Comorbidities
Diabetes mellitus	59	(32)	7 (19)	52	(35)	.06	-	-
Obstructive uropathy	14	(8)	2 (5)	12	(8)	.74	-	-
Renal transplant	2	(1)	0 (0)	2	(1)	1.00	-	-
HIV infection	4	(2)	1 (3)	3	(2)	1.00	-	-
Dementia	11	(6)	0 (0)	11	(8)	.12	-	-
Stroke	17	(9)	2 (5)	15	(10)	.53	-	-
Other neurologic deficits c	11	(6)	2 (5)	9	(6)	1.00	-	-
Prior UTI	67	(36)	14 (38)	53	(36)	.84	-	-
Chronic indwelling catheter	17	(9)	2 (5)	15	(10)	.53	-	-
Urinalysis findings
Leukocyte >=10 cells/HPF	60	(33)	19 (51)	41	(28)	.007	2.40 (1.07-5.38)	.03
Positive nitrite test	42	(23)	20 (54)	22	(15)	b.001	6.57 (2.89-14.94)	b.001
Data are in n (%), unless otherwise indicated. HIV indicates human immunodeficiency virus; LTAC, long-term Acute care facilities; UTI, urinary tract infection. a For univariate analyses. b For multivariate analyses. c Owing to brain tumors, Multiple sclerosis, and spinal cord pathology.

advanced age, presence of Gram-negative organisms in the urine, urine white blood cell of 90 cells/mL or greater, and altered mental status [3,7]. Abnormal urinalysis findings including pyuria and positive nitrite test usually represent the Inflammatory conditions and presence of bacteria in the genitourinary tract. These findings are nonspecific and not useful for differentiating between AB and SUTI [1,2]. We found that urine white blood cell of 10 cells per HPF or greater and positive urine nitrite were significantly associated with antibiotic treatment for AB in our ED setting. These findings identify a common misconception in the diagnosis of SUTI and suggest that antibiotics may have been initiated merely because of results of laboratory tests. Of note, other patient factors such as recent health care exposure, diabetes mellitus, immunocompromised status, neurologic deficits, and presence of indwelling catheter were not significantly associated with antibiotic therapy for AB.

In summary, we found that a large proportion of patients with AB underwent urine testing without a specified indication and received antibiotic therapy based on urine findings. Further studies are needed to assess physician knowledge and attitudes toward the management of AB and to guide interventions and strategies to reduce unnecessary urine testing and antibiotic use in the ED setting.

Thana Khawcharoenporn MD

Shawn Vasoo MD Section of Infectious Diseases Rush University Medical Center Chicago, Illinois 60612, USA

E-mail address: [email protected]

Edward Ward MD Department of Emergency Medicine Rush University Medical Center Chicago, Illnois 60612, USA

Kamaljit Singh MD Section of Infectious Diseases Rush University Medical Center Chicago, Illinois 60612, USA

doi:10.1016/j.ajem.2011.04.007

References

1. Nicolle LE, Bradley S, Colgan R, et al. Infectious Diseases Society of America guidelines for the diagnosis and treatment of asymptomatic bacteriuria in adults. Clin Infect Dis 2005;40:643-54.
2. Colgan R, Nicolle LE, McGlone A, et al. Asymptomatic bacteriuria in adults. Am Fam Physician 2006;74:985-90.
3. Cope M, Cevallos ME, Cadle RM, et al. Inappropriate treatment of catheter-associated asymptomatic bacteriuria in a tertiary care hospital. Clin Infect Dis 2009;48:1182-8.
4. Khawcharoenporn T, Vasoo S, Ward E, et al. High rates of quinolone resistance among urinary tract infections in the ED. Am J Emerg Med 2010 [Epub ahead of print] doi:10.1016/j.ajem2010.09.030.
5. Rubin RH, Beam Jr TR, Stamm WE. An approach to evaluating antibacterial agents in the treatment of urinary tract infection. Clin Infect Dis 1992;14:S246-51.
6. Horan TC, Andrus M, Dudeck MA. CDC/NHSN surveillance definition of health care-associated infection and criteria for specific types of infections in the acute care setting. Am J Infect Control 2008;36:309-32.
7. Silver SA, Baillie L, Simor AE. Positive urine cultures: a major cause of inappropriate antimicrobial use in hospitals? Can J Infect Dis Med Microbiol 2009;20:107-11.

Rate control medications for atrial fibrillation in the setting of hypercalcemia

To the Editor,

We have read with great interest the article by Mert et al [1]. The authors presented a case with atrial fibrillation that developed pulmonary edema in the setting of hypercalcemia secondary to hyperparathyroidism. However, an interesting topic that the authors did not mention about was patient’s rate control medication for atrial fibrillation. Every rate control medication has different effects by hypercalcemia and eventually can cause pulmonary edema. Verapamil acts primarily at the cell membrane and inhibits transmural fluxes of calcium. The drug slows ventricular response in atrial fibrillation by inhibiting the atrioventricular conduction. This effect is abolished in the patient when serum calcium rises to abnormal levels, and slowing of the ventricular response is achieved by reducing serum calcium, whereas verapamil treatment was maintained [2]. Conversely, hypercalcemia- and hypokalemia-inducing drugs, heart rate-lowering drugs, and drugs that prolong the QT interval or slow cardiac conduction can potentiate the cardiac adverse effects of digoxin [3]. Hypercalcemia should be considered in the evaluation of any patient with an unexplained bradyarrhyth- mia or in a patient on optimal dose of digoxin.

Wisit Cheungpasitporn MD Teeranun Jirajariyavej MD Sirisak Chanprasert MD Department of Internal Medicine Bassett Medical Center Cooperstown, NY 13326, USA

E-mail address: [email protected] doi:10.1016/j.ajem.2011.04.010

References

1. Mert M, Uzuncan FB, Aydin MM, Kocabay G, Ortakoylu A. A hyperparathyroid case with pulmonary edema: can hypercalcemia trigger pulmonary edema? Am J Emerg Med 2011. doi:10.1016/j. ajem.2010.12.033 [Epub ahead of print].
2. Bar-Or D, Gasiel Y. Calcium and calcifecol antagonize effect of verapamil in atria1 fibrillation. Br Med J 1981;282:1585.
3. Vella A, Gerber TC, Hayes DL, Reeder GS. Digoxin, hypercalcaemia, and cardiac conduction. Postgrad Med J 1999;75(887):554-6.