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because these patients often abuse ethanol as well, and ethanol can raise the serum osmolal gap. The American Academy of Clinical Toxicology practice guidelines on the treatment of methanol poisoning recommend sodium bicarbonate via intravenous bolus for any patient with a pH less than 7.3 [5] and treatment with hemodialysis in any patient with a suspected toxic methanol ingestion who has a severe, otherwise unexplained anion gap metabolic acidosis and significant plasma osmolal gap.

Narat Srivali, MD Department of Pulmonary and Critical Care Medicine, Mayo Clinic Rochester, MN 55901, USA Corresponding author. Tel.: +1 607 435 5149 E-mail address: [email protected] Vareena Laohaphan, MD Department of Emergency Medicine, Phramongkutklao College of Medicine Bangkok 10440, Thailand Charat Thongprayoon, MD Department of Internal Medicine, Mayo Clinic, Rochester, MN 55901, USA

http://dx.doi.org/10.1016/j.ajem.2014.09.033 References [1] Bologa C, Ciuhodaru L, Coman A, Petris O, Sorodoc L, Lionte C. Am J Emerg Med 2014; 32(9):1154.e1–2. [2] Rose BD, Post TW. Clinical physiology of acid–base and electrolyte disorders. 5th ed. McGraw-Hill: New York; 2001 607. [3] Gennari FJ. Current concepts. Serum osmolality. Uses and limitations. N Engl J Med 1984;310(2):102–5. [4] Jacobsen D, Bredesen JE, Eide I, Ostborg J. Anion and osmolal gaps in the diagnosis of methanol and ethylene glycol poisoning. Acta Med Scand 1982;212(1–2): 17–20. [5] Barceloux DG, Bond GR, Krenzelok EP, Cooper H, Vale JA, American Academy of Clinical Toxicology Ad Hoc Committee on the Treatment Guidelines for Methanol PoisoningJ. American Academy of Clinical Toxicology practice guidelines on the treatment of methanol poisoning. Toxicol Clin Toxicol 2002;40(4): 415–46.

Table 1 Characteristics of subjects including those recommended and not recommended to receive antiviral treatment according to 2011 Centers For Disease Control and Prevention criteria

No. of subjects Age (y) Male sex, n (column %) Race, n (column %) African American White Other Influenza season, n (column %) 2008-2009 2009-2010 2010-2011 2011-2012 2012-2013 Type of influenza, n (column %) Influenza A Influenza B Diagnosis, n (column %) Influenza-like Illness ED diagnosis of influenza Treatment criteria, n (column %) Hospital admission Complications/Pneumonia Age ≥65 y Chronic disease Pulmonary Cardiovascular Renal Hematologic Metabolic Neurologic Immunosupression Pregnancy Morbid obesity Resides in nursing home Native American ED treatment, n (column %) Antiviral given in ED Antiviral prescription only Any antiviral treatment from ED Antibiotic given in ED

All

Recommended to treat

Not recommended to treat

342 37 (23-50) 141 (41)

282 42 (24-52) 111 (39)

60 25 (21-35) 30 (50)

237 (69) 47 (14) 58 (17)

224 (79) 39 (14) 19 (7)

49 (82) 8 (13) 3 (5)

40 (12) 154 (45) 78 (23) 16 (5) 54 (16)

31 (11) 128 (45) 67 (24) 9 (3.2) 47 (17)

9 (15) 26 (43) 11 (18) 7 (12) 7 (12)

308 (90) 33 (10)

261 (93) 20 (7)

47 (78) 13 (22)

206 (60) 72 (21)

161 (57) 57 (20)

45 (75) 15 (25)

177 (52) 54 (16) 19 (6)

177 (63) 54 (19) 19 (7)

NA NA NA

132 (39) 84 (25) 39 (11) 26 (8) 59 (17) 32 (9) 85 (25) 3 (1) 6 (2) 0 (0) 0 (0)

132 (47) 84 (30) 39 (14) 26 (9) 59 (21) 32 (11) 85 (30) 3 (1) 6 (2) 0 (0) 0 (0)

NA NA NA NA NA NA NA NA NA NA NA

106 (31) 24 (15) 130 (38)

100 (35) 16 (15) 116 (41)

6 (10) 8 (13) 14 (23)

164 (48)

152 (54)

12 (20)

NA, not available.

ED compliance with influenza antiviral recommendations☆,☆☆

To the Editor, Studies indicate that antiviral treatment improves clinical outcomes for patients at increased risk for, or with existing influenza complications, and is thus recommended by the Centers for Disease Control and Prevention (CDC), World Health Organization, and Infectious Disease Society of America [1–3]. However, despite growing evidence that antiviral medications reduce influenza-related morbidity and mortality, there continues to be a discordance between recommendations and clinical practice [4]. Adherence to CDC antiviral guidelines for influenza has proven to be as low as 50%; however, this estimate used a clinical diagnosis of influenza, rather than the more accurate laboratory diagnosis, leading to potential bias [4]. Thus, adherence to CDC guidelines in a population of subjects with confirmed influenza remains unknown. ☆ This work was supported by the Johns Hopkins Clinical Research Scholars Program (5KL2RR025006). ☆☆ This work was not been previously presented.

Given the challenges of diagnosing influenza in the emergency department (ED) and the importance of appropriately treating patients with existing or at increased risk for complications, we examined adherence to CDC antiviral recommendations among ED patients with laboratory-confirmed influenza. Understanding these treatment patterns could provide opportunities to improve care and long-term outcomes for patients diagnosed as having influenza in the ED. We conducted an observational cohort study of ED patients at an urban, university-affiliated tertiary care center. All ED subjects with laboratory-confirmed influenza between December 2008 and 2012 were included, with the exception of those who left prior to final workup and treatment. With approval of the institutional review board, 2 reviewers independently extracted data from electronic medical records, including the following: subject demographics, current symptoms and medications, medical history, initial vital signs, laboratory data, final ED management and diagnosis, and disposition from the ED. Presence of influenza-like illness was based on the CDC criteria of fever of at least 37.8°C with cough or sore throat [5]. Antibiotic and antiviral administration was recorded as none, ED administered, or prescription at discharge. The Pneumonia Severity Index was calculated

Correspondence / American Journal of Emergency Medicine 32 (2014) 1534–1552 Table 2 Characteristics of subjects recommended to receive antiviral treatment according to 2011 Centers For Disease Control and Prevention criteria

No. of subjects Influenza season 2008-2009 2009-2010 2010-2011 2011-2012 2012-2013 Type of influenza Influenza A Influenza B Diagnosis Influenza-like Illness ED diagnosis of influenza Alternate diagnosis Infiltrate on chest x-ray ED diagnosis of pneumonia Antibiotic treatment in the ED Severity Hospital admission Pneumonia Severity Index I II III IV V Positive influenza test result available before disposition Symptoms less than 48 h Immunosuppressed

Recommend to receive antiviral treatment, n (column %)

Treated with antiviral, n (column %)

Not treated with antiviral, n (column %)

282

116

166

31 (11%) 128 (45) 67 (24) 9 (3) 47 (17)

4 (3) 62 (53) 22 (19) 6 (5) 22 (19)

27 (16) 66 (40) 45 (27) 3 (2) 25 (15)

261 (93) 20 (7)

113 (97) 3 (3)

148 (89) 17 (10)

.009

161 (57)

70 (60)

91 (55)

.356

57 (20)

42 (36)

15 (9)

65 (23)

17 (15)

48 (29)

.005

54 (19)

16 (14)

38 (23)

.053

152 (54)

49 (42)

103 (62)

.001

177 (63)

66 (57)

111 (67)

.088

159 (56) 66 (23) 33 (12) 21 (7) 3 (1) 84 (30)

66 (57) 22 (19) 18 (16) 9 (8) 1 (1) 55 (47)

93 (56) 44 (27) 15 (9) 12 (7) 2 (1) 29 (17)

P

.001

b.001

.518

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This study found that only 41% of patients with confirmed influenza who met CDC criteria for antiviral administration received this treatment in the ED. This discordance might reflect challenges in diagnosing influenza, as evidenced by this and previous studies demonstrating the positive correlation between influenza testing and antiviral use [7,8]. The current lack of rapid, reliable influenza tests makes diagnosis and timely influenza treatment challenging. Although highly sensitive, traditional real-time polymerase chain reaction–based tests take several hours to result, reducing their clinical use in the ED. Rapid antigen tests are faster but have lower sensitivities that necessitate adjunctive confirmation [9]. Emerging rapid polymerase chain reaction–based tests may prove advantageous; however, they are not yet in widespread use. The correlation in our study between positive influenza test results while the patient was still in the ED and antiviral treatment suggests that accessible, rapid, sensitive influenza tests may improve provider adherence to CDC guidelines. As with any retrospective evaluation, there exist potential inaccuracies in medical records. In addition, testing and treatment patterns at this single institution may not represent that of other facilities. Although evaluating only laboratory-confirmed influenza cases potentially decreases generalizability, it was necessary given the aforementioned limitations of clinical diagnoses. In summary, there is poor adherence to CDC recommendations for antiviral treatment among ED patients with laboratoryconfirmed influenza. Hospital admission and severity of illness are not associated with antiviral treatment. However, provider diagnosis of influenza and a positive influenza test result during the ED visit are associated. These findings suggest that integrating a sensitive, rapid influenza test into ED care may improve adherence to CDC antiviral recommendations.

b.001

150 (53)

73 (63)

77 (46)

.007

85 (30)

46 (40)

39 (23)

.004

for each patient as previously described [6]. Subjects were first separated by 2011 CDC antiviral recommendations and then stratified by management. Data were analyzed using Stata: Release 11 (StataCorp LP, 2009, College Station, TX). We used nonparametric statistics and χ 2 test for statistical comparisons. Throughout 5 influenza seasons, 342 adults with positive ED influenza test results were included. Of these, 282 (82%) met CDC criteria for antiviral treatment, whose characteristics are displayed in Table 1. Among all subjects, 130 (38%) received antiviral treatment in the ED, whereas 41% (95% confidence interval, 36%-47%) of recommended patients received antiviral treatment. We compared recommended subjects who actually received treatment with those who did not, as shown in Table 2. Symptom duration correlated with antiviral treatment, such that patients with fewer than 48 hours of symptoms were more commonly treated. Patients with a clinical influenza diagnosis recorded in the electronic medical record and patients with a positive influenza test result prior to discharge more commonly received antiviral treatment. Patients with chest xray infiltrates and those treated with antibiotics were less likely to receive antiviral treatment. Using the Pneumonia Severity Index as a marker of disease severity, there was no association between disease severity and antiviral treatment. Similarly, there was no significant correlation between hospital admission and antiviral administration.

Andrea F. Dugas, MD, PhD⁎ Bradley Monteforte Aditi Puri, MD Mohamed Awad, MBBCH Yu-Hsiang Hsieh, PhD Richard Rothman, MD, PhD Department of Emergency Medicine, Johns Hopkins University Baltimore, MD ⁎ Corresponding author. Johns Hopkins Department of Emergency Medicine, 5801 Smith Ave, Davis Building Suite 3220 Baltimore MD 21209 Tel.: +1 410 735 6453; fax: +1 410 735 6425 E-mail address: [email protected]

http://dx.doi.org/10.1016/j.ajem.2014.09.032 References [1] Fiore AE, Fry A, Shay D, Gubareva L, Bresee JS, Uyeki T. Antiviral agents for the treatment and chemoprophylaxis of influenza —recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Surveill Summ 2011;60:1–24. [2] Harper SA, Bradley JS, Englund JA, File TM, Gravenstein S, Hayden FG, et al. Seasonal influenza in adults and children—diagnosis, treatment, chemoprophylaxis, and institutional outbreak management: clinical practice guidelines of the Infectious Diseases Society of America. Clin Infect Dis 2009; 48:1003–32. [3] WHO recommendations on the use of rapid testing for influenza diagnosis. Accessed March 12, 2013, at http://www.who.int/influenza/resources/documents/rapid_testing/en/index.html; 2005. [4] Hsieh Y-H, Kelen GD, Dugas AF, Chen K-F, Rothman RE. Emergency physicians' adherence to Center for Disease Control and Prevention Guidance during the 2009 influenza A H1N1 pandemic. West J Emerg Med 2013;14:191–9. [5] Overview of influenza surveillance in the United States. Accessed November 21, 2013, at http://www.cdc.gov/flu/pdf/weekly/overview.pdf; 2013.

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[6] Fine MJ, Auble TE, Yealy DM, Hanusa BH, Weissfeld LA, Singer DE, et al. A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med 1997;336:243–50. [7] Rothberg MB, Bonner AB, Rajab MH, Kim HS, Stechenberg BW, Rose DN. Effects of local variation, specialty, and beliefs on antiviral prescribing for influenza. Clin Infect Dis 2006;42:95–9.

[8] Peters TR, Suerken CK, Snively BM, Winslow JE, Nadkarni MD, Kribbs SB, et al. Influenza testing, diagnosis, and treatment in the emergency department in 2009-2010 and 2010-2011. Acad Emerg Med 2013;20:786–94. [9] Centers for Disease Control and Prevention (CDC). Evaluation of rapid influenza diagnostic tests for detection of novel influenza A (H1N1) Virus—United States, 2009. MMWR Morb Mortal Wkly Rep 2009;58:826–9.