The Prevalence of Bacteremia in Pediatric Patients With Community-Acquired Pneumonia: Guidelines to Reduce the Frequency of Obtaining Blood Cultures

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1 RESEARCH ARTICLE The revlence of Bcteremi in editric tients With Community-Acquired neumoni: Guidelines to Reduce the Frequency of Obtining Blood Cultures bstrct OBJECTIVE: The gol of this study ws to determine the prevlence of bcteremi in peditric ptients with community-cquired pneumoni (CA) t our institution nd to test the effectiveness of newly developed guidelines for obtining blood cultures. METHODS: Using recent literture nd locl expert opinion, institutionl guidelines for obtining blood cultures in peditric ptients with CA were developed. A retrospective chrt review of children treted in the emergency deprtment or dmitted for CA from Jnury 2010 through June 2011 ws conducted. Demogrphic nd clinicl dt were collected, including results of blood cultures. χ 2 tests ssessed for vribles ssocited with bcteremi, whether blood culture ws obtined, nd if the decision to obtin culture ws pproprite bsed on our guidelines. RESULTS: The study included 330 ptients; 155 (47%) blood cultures were obtined in our ptient popultion. Five cultures were true-positive findings, mking the prevlence of bcteremi 3.2% in ptients with blood cultures nd 1.5% in ll ptients. All 5 true positive results met criteri for blood culture bsed on our guidelines. Applying our guidelines retrospectively, the decision to obtin blood culture met criteri in 55% of the cses. Bivrite nlysis showed tht ptients dischrged from the emergency deprtment hd higher rtes of guideline-pproprite decisions thn ptients dmitted. Rdiogrphic findings were ssocited with mking guideline-pproprite decision regrding blood culture. CONCLUSIONS: Instituting locl guidelines tht limit the frequency of obtining blood cultures in peditric ptients with CA is likely to cpture ny ptient with bcteremi. This study suggests tht blood cultures my not need to be routinely obtined in ll ptients dmitted to the hospitl with CA. neumoni in peditric ptients is significnt illness in the United Sttes nd worldwide. After the widespred use of the Hemophilus infl uenze type B vccine nd pneumococcl conjugte vccine, the prevlence of bcteremi in peditric ptients with pneumoni is reported to be 1% to 3%. 1 5 Nevertheless, blood cultures re obtined in up to 33% of these ptients, 4 nd flse-positive rtes rnge from 0.8% to 7.3%. 6 9 The utility of positive blood culture results, especilly in peditric ptients, remins uncler. Severl dult studies hve found tht positive culture results rrely lter clinicl mngement. Some peditric literture supports the limited clinicl utility of positive blood culture results, 1,10 wheres AUTHORS Dniel Heine, MD, 1 Christin Cochrn, MD, 2 Meliss Moore, MD, 2 M. Olivi Titus, MD, 2 Annie Lintzenich Andrews, MD, MSCR 2 1 Deprtment of editrics, Division of Generl editrics nd Adolescent Medicine, Georgi Helth Sciences University, August, Georgi; nd 2 Deprtment of editrics, Divisions of Generl editrics nd Emergency Medicine, Medicl University of South Crolin, Chrleston, South Crolin KEY WORDS bcteremi, blood cultures, community-cquired pneumoni, guidelines ABBREVIATIONS CA: community-cquired pneumoni ED: emergency deprtment IDSA: Infectious Diseses Society of Americ MUSC: Medicl University of South Crolin WBC: white blood cell doi: /hpeds Address correspondence to Dniel Heine, MD, Division of Generl editrics nd Adolescent Medicine, Georgi Helth Sciences University, th St, BG 2123, August, GA E-mil: dheine@gru.edu HOSITAL EDIATRICS (ISSN Numbers: rint, ; Online, ). Copyright 2013 by the Americn Acdemy of editrics FINANCIAL DISCLOSURE: The uthors hve no fi nncil reltionships relevnt to this rticle to disclose. FUNDING: No externl funding. 92 VOLUME 3 ISSUE 2

2 nother study sw chnge in mngement in >80% of ptients with positive result on blood culture. 4 By obtining blood cultures in only highrisk ptients nd certin clinicl scenrios, the dded costs nd length of hospitliztion ssocited with flsepositive findings could be reduced. Adult studies hve estimted tht flse-positive blood culture result dds ~$6000 to hospitliztion costs nd 4 to 8 dys to the length of sty. 11,12 One peditric retrospective chrt review nlyzed 2971 ptients ged <3 yers who hd documented fever nd blood culture obtined in n emergency deprtment (ED) setting. They estimted net cost of >$ to reevlute children mnged s outptients who hd flse-positive result on blood culture. 13 Furthermore, flsepositive blood culture results led to brodened ntibiotic coverge, often with vncomycin, subsequently contributing to incresed ntibiotic resistnce. 14 In 2011, the Infectious Diseses Society of Americ (IDSA) published guidelines for the clinicl mngement of community-cquired pneumoni (CA) in both inptient nd outptient settings. 15 In terms of blood cultures in the outptient setting, the IDSA sttes tht blood cultures should not be routinely obtined in nontoxic, fully immunized children. However, the IDSA guidelines recommend tht blood cultures should be obtined in children who fil to demonstrte improvement fter the strt of pproprite ntibiotic therpy or who require hospitliztion for moderte to severe CA, especilly complicted pneumoni. The purpose of the current study ws to determine the prevlence of bcteremi in ptients with CA t our institution nd to test the effectiveness of newly developed guidelines for obtining blood cultures in peditric ptients with CA through retrospective chrt review before institutionl guideline doption. METHODS This study ws collbortive effort mong mny specilties t the Medicl University of South Crolin (MUSC), including peditric emergency medicine, hospitlists, nd infectious diseses. The locl guidelines for obtining blood cultures in peditric ptients with CA were developed by using recent literture, s well s locl expert opinion, nd included: (1) febrile nd ge <6 months or febrile with delyed immuniztions; (2) ptients who re immunocompromised; (3) chronic medicl conditions predisposing to severe or recurrent pneumoni; (4) hospitliztion <14 dys before the dignosis of pneumoni; (5) toxic-ppering or requiring ICU dmission; (6) rdiogrphic concern for n effusion, empyem, or bscess; nd (7) centrl line in plce. After development of these guidelines, retrospective chrt review ws conducted on the children dischrged from the ED or hospitl from Jnury 2010 through June 2011 to determine bcteremi prevlence nd to test the clinicl effectiveness of the guidelines before institutionl doption. Demogrphic nd clinicl dt were collected on children dischrged from the peditric ED or the Children s Hos pitl t MUSC during the study period. Interntionl Clssifi ction of Diseses, Ninth Revision codes ( , , nd 513) were used to identify ptients who hd primry dignosis of pneumoni. Relevnt medicl history, immuniztion sttus, initil physicl exmintion findings (including generl ppernce, respirtory rte, nd oxygen sturtion), white blood cell (WBC) count, chest rdiogrph findings, nd blood culture results were recorded. For chest rdiogrphs, the finlized reds by the ttending rdiologists were documented when vilble. For blood cultures, pthogenic bcteri were defined s Streptococcus pneumonie, Stphylococcus ureus, group A β-hemolytic streptococci, nd Hemophilus infl uenze; contminnts were defi ned s cogulse-negtive Stphylococcus species, α-hemolytic streptococci, Micrococcus species, nd Corynebcterium species. 4 The decision to obtin blood cultures ws documented s either pproprite or inpproprite bsed on our guidelines. Bivrite nlysis ws used to determine wht clinicl chrcteristics were ssocited with obtining blood cultures, mking guideline-pproprite decisions, nd bcteremi. The institutionl review bord t MUSC pproved this study. RESULTS In totl, there were 330 ptients in the study, with men ge of 4.9 yers (rnge: 0 18 yers). Generl demogrphic nd clinicl dt re given in Tble 1. Regrding disposition, 40% were dischrged from the ED, 27% were dmitted from the peditric ED, nd 33% were dmitted from n outside fcility or primry cre provider. A focl infiltrte ws seen on 70.5% of the chest rdiogrphs, nd evidence of n effusion or empyem ws documented for 9% of the rdiogrphs. In our ptient popultion, 71 ptients (21.5%) hd WBC count > /ml. A totl of 155 (47%) blood cultures were obtined in our ptient popultion. Of the locl guidelines, the most common criteri these ptients met were 93

3 TABLE 1 Demogrphic nd Clinicl Chr cteristics of the Study opultion, N = 330 Chrcteristics N (%) Rce White 148 (45) Blck 136 (41) Hispnic 41 (13) Other 3 (1) Gender Mle 180 (55) Femle 149 (45) Clinicl exmintion Toxic-ppering 19 (6) Oxygen requirement 90 (28) Disposition Dischrged from ED 133 (40) Admitted from ED 88 (27) Admitted from OSH/C 108 (33) Medicl history Asthm 63 (19) Cystic fibrosis 7 (2) Sickle cell disese 11 (3) Immunocompromised 14 (4) Rdiogrphic findings Norml 11 (3.5) Virl versus RAD 53 (17) Focl infiltrte 220 (70.5) Effusion or empyem 28 (9) WBC count ( 10 3 /μl) > (21.5) < (78.5) OSH, outside hospitl; C, primry cre physicin; ED, peditric emergency deprtment; RAD, rective irwy disese. ercentges re bsed on the totl 312 chest rdiogrphs obtined. rdiogrphic evidence of n effusion, empyem, or bscess, nd toxicppering or ICU dmission (Tble 2). Of the blood cultures obtined, 55% met criteri nd 45% did not meet criteri bsed on our guidelines. A totl of 145 (94%) blood cultures hd negtive results, nd 10 cultures hd positive TABLE 2 Guideline Findings in tients With Blood Culture Drwn, N = 155 Institutionl Guideline Criteri N (%) Febrile nd <6 mo of ge or delyed 14 (9) immuniztions Immunocompromised 14 (9) Chronic medicl conditions 20 (13) Hospitliztion <14 d before 2 (1) dignosis Toxic-ppering nd/or ICU 26 (17) dmission Effusion, empyem, bscess 28 (18) Centrl line 4 (3) results. Five cultures were true-positive fi ndings, mking the prevlence of bcteremi 3.2% in ptients with blood cultures nd 1.5% in ll ptients. However, 50% of positive blood culture results were found to be contminnts. Of the ptients with n effusion or empyem, 46% underwent pleurl fluid nlysis. leurl fluid culture findings were positive in 3 ptients (23%), of whom 2 lso hd positive blood culture result (Tble 3). There ws no bounce-bck dmission in which bcteremi ws subsequently identifi ed. One ptient ws initilly dischrged from the peditric ED on orl ntibiotics without blood culture obtined nd returned with worsening symptoms. Repet chest rdiogrph demonstrted new effusion, but the blood culture result ws negtive. In fct, ll ptients with bcteremi were found to hve positive blood culture result during their initil mngement before ny tretment ws initited. Of the 5 cses of bcteremi, there were 3 cses of S pneumonie, 1 cse of E coli, nd 1 cse of group A Streptococcus (Tble 3) infection. Not only were ll 5 ptients treted s inptients from their initil presenttion, but ll ptients with bcteremi lso hd rdiogrphic evidence of n effusion or empyem. In ddition, ll 5 ptients were dmitted to the ICU nd/or described s being septic, thereby meeting institutionl criteri. However, none of the ptients with bcteremi hd sickle cell disese or other chronic medicl conditions, were immunocompromised, were recently hospitlized, or hd centrl line in plce. All ptients who hd bcteremi were initilly treted with vncomycin, but this decision ws likely bsed on rdiogrphic findings nd severity of illness becuse the blood culture result hd not yet been determined to be positive. However, only 1 ptient with flse-positive blood culture result received vncomycin but ws then dischrged on cefdinir fter being hospitlized for only 2 dys. Bivrite nlysis reveled sttisticlly significnt ssocitions between ptient ge, disposition, chest rdiogrph findings, nd whether blood culture ws obtined. tients dischrged from the ED were less likely to hve blood culture obtined, nd ptients with n effusion or empyem were more likely to hve blood culture obtined. Disposition nd chest rdiogrph findings were lso significntly sso cited with whether guideline-ppro prite decision ws mde. Leuko cytosis, de fined s WBC count > / ml, ws significntly sso cited with bcteremi (Tble 4). DISCUSSION In this study, the prevlence of bcteremi in ptients with CA ws 3.2%, which is similr to results of recently published studies. 1 5 All 5 cses of bcteremi hd rdiogrphic evidence of n effusion or empyem nd therefore wrrnted blood culture bsed on our institutionl guidelines. Four ptients were dmitted to the ICU nd described s toxic-ppering; nother ptient ws described s being toxic without requiring ICU dmission. Although ll 5 ptients were treted s inptients nd hd similr rdiogrphic findings, there ws no other unifying criterion tht ws met by ll ptients. Despite the low prevlence of bcteremi, blood cultures re routinely obtined s prt of the initil evlution of ptients dmitted for CA. The 94 VOLUME 3 ISSUE 2

4 TABLE 3 Detils of the 5 Cses of True Bcteremi No. Blood Culture thogen Age (y) ICU Toxic Medicl History 1 Group A 2 Yes No Congenitl Streptococcus chylothorx WBC Count ( 10 3 /ml) Chest Rdiogrph Result leurl Fluid Culture Result Antibiotics 19.2 Effusion/empyem Negtive Initil: vncomycin, cefotxime Finl: clindmycin 2 S pneumonie 1 No Yes None 20.8 Effusion/empyem S pneumonie Initil: vncomycin, ceftrixone Finl: levofloxcin 3 b E coli <1 Yes Yes Trumtic birth 36 Effusion/empyem E coli Initil: mpicillin, cefotxime, vncomycin Finl: moxicillin 4 S pneumonie 2 Yes No None 14.6 Effusion/empyem Negtive Initil: ceftrixone, vncomycin Finl: linezolid 5 S pneumonie 5 Yes No None 26 Effusion/empyem Negtive Initil: ceftrixone, vncomycin, clindmycin dded Finl: moxicillin-clvulnte, clindmycin This ptient previously underwent resection of the right lobe of the lung. b This ptient ws <1 month of ge nd presented to the ICU in urosepsis. Ultimtely, E coli ws isolted in the urine, blood, nd pleurl fluid nd from sclp bscess IDSA guidelines 15 do not recommend routine use of blood cultures in fully immunized, otherwise helthy children dignosed with CA but do recommend blood cultures in ptients dmitted to the hospitl with moderte to severe CA. We propose tht not ll ptients dmitted for CA re modertely to severely ill nd therefore do not wrrnt routine blood cultures. Specifi clly, well-ppering ptients without rdiogrphic evidence of n effusion or empyem who re dmitted primrily for mild hypoxi do not need blood culture obtined. Furthermore, lthough our guidelines do not explicitly ddress ptients who hve filed to improve with pproprite outptient therpy, there were zero cses of ptients in our study presenting TABLE 4 Bivrite Anlysis Illustrting the roportion of Children Who Hd Blood Culture Obtined, Hd Locl Guideline-Approprite Decision, nd Hd Bcteremi, N = 330 Chrcteristic % Getting Culture % Approprite Decision % True ositive Culture Result Age, y NR < Disposition <.0001 < b Dischrge from ED Admitted from ED Admitted from OSH Chest rdiogrph findings <.0001 <.0001 <.0001 b Norml Virl versus RAD Focl infiltrte Effusion/empyem WBC count ( 10 3 /μl) < <.01 > < OSH, outside hospitl; ED, peditric emergency deprtment; RAD, rective irwy disese. vlue not reported (NR) becuse χ 2 is not vlid test with frequency of true positive blood culture result of zero in 6- to 11-yer-olds nd 12- to 17-yer-olds. The Fisher exct test ws not pproprite for 4 2 tble. b Fisher exct test ws run for these vribles due to cell frequencies of zero. For disposition, ptients dmitted from ED nd OSH were collpsed into 1 group. For chest rdiogrph findings, norml, virl versus RAD, nd focl infiltrte were collpsed into 1 group. fter pproprite outptient ntibiotic therpy who were subsequently found to hve bcteremi. The overll low prevlence of bcteremi in this ptient popultion hs been estblished, yet the clinicl utility of positive blood culture results remins uncler. In retrospective cohort study of 355 immunocompetent dults dmitted for CA, Corbo et l 9 found tht mngement ws chnged by clinicl sttus in 49% of ptients nd by blood culture results in 5% of ptients. Hickey et l 1 performed retrospective chrt review of 939 peditric ptients with rdiogrphic evidence of pneumoni; 409 blood cultures were obtined. They found no chnge in the mngement of ny of the 11 peditric ptients with pneumoni nd true positive blood culture result. In ddition, Leonrd nd Bettie 10 studied 1159 blood cultures in nerly ptients evluted t peditric ccident nd ED over 7 months. Of 26 true positive results on blood culture, only 5 significntly influenced clinicl mngement. Furthermore, the possibility of flse-positive results cn led to repet testing nd prolonged hospitliztion. 11,12 More specifi clly, Srd 95

5 et l 13 performed n 8-yer retrospective chrt review of 2971 ptients ged <3 yers who presented to the ED with documented fever nd hd blood culture obtined. They found tht bout one-third of children mnged s outptients who hd flse-positive blood culture results underwent reevlution, to include n ED visit for repet blood culture nd possibly further testing nd prenterl ntibiotics. The net cost of reevluting these ptients ws estimted to be >$ On the contrry, Shh et l 4 found tht mngement ws chnged in 5 of 6 ptients with true positive result on blood culture. However, the rgument could be mde tht pproprite decisions regrding ntibiotics could hve been determined bsed on clinicl sttus lone. In our study, most ptients were strted empiriclly on ceftrixone nd dischrged from the hospitl on moxicillin or moxicillin-clvulnte, nd most ptients either did not hve blood culture performed or hd negtive blood culture result. Of the 5 ptients with bcteremi, chnges in ntibiotics were bsed on blood culture results in 2 ptients nd on pleurl fluid culture results in 2 ptients. The rtionle to chnge ntibiotics ws uncler in the finl ptient with bcteremi bsed on our retrospective chrt review. This study hs severl limittions. First, becuse blood cultures were not obtined for ll ptients, the true prevlence of bcteremi in this ptient popultion could not be determined. However, no ptients were found to hve bcteremi on subsequent evlutions nd hospitliztions. Although the contmintion rte ws elevted t 3.2% in our study, 50% of positive blood culture results were contminnts. This study ws performed only on ptients t our institution over n 18-month spn. Therefore, these results my not be generlizble to other hospitls nd institutions. In ddition, we hd no wy of knowing if ptients dischrged from the peditric ED were subsequently dmitted to nother hospitl. This study suggests tht instituting locl guidelines to limit the frequency of blood cultures in ptients with pneumoni will likely cpture ll ptients with cliniclly significnt bcteremi. This study supports the recent recommendtions tht blood cultures do not need to be routinely obtined in ll ptients with CA. For future qulity improvement efforts surrounding guideline implementtion, retrospective chrt review cn be useful wy to test the predicted clinicl effectiveness before institutionl implementtion nd my encourge guideline doption. Future studies to exmine the clinicl utility of positive blood culture results could strengthen the rgument ginst routine blood cultures. In ddition, cost-effectiveness nlysis of the finncil effect of reducing the number of blood cultures, including decresed length of sty nd decresed lbortory costs, could be helpful. REFERENCES 1. Hickey RW, Bowmn MJ, Smith GA. Utility of blood cultures in peditric ptients found to hve pneumoni in the emergency deprtment. Ann Emerg Med. 1996;27(6): Bondio WA. Bcteremi in febrile children with lobr pneumoni nd leukocytosis. editr Emerg Cre. 1988;4(4): Shh SS, Alpern ER, Zwerling L, McGown KL, Bell LM. Risk of bcteremi in young children with pneumoni treted s outptients. Arch editr Adolesc Med. 2003;157(4): Shh SS, Dugn MH, Bell LM, et l. Blood cultures in the emergency deprtment evlution of childhood pneumoni. editr Infect Dis J. 2011;30(6): Rmsey BW, Mrcuse EK, Foy HM, et l. Use of bcteril ntigen detection in the dignosis of peditric lower respirtory trct infections. editrics. 1986;78(1): Wterer GW, Jennings SG, Wunderink RG. The impct of blood cultures on ntibiotic therpy in pneumococcl pneumoni. Chest. 1999;116(5): Kennedy M, Btes DW, Wright SB, Ruiz R, Wolfe RE, Shpiro NI. Do emergency deprtment blood cultures chnge prctice in ptients with pneumoni? Ann Emerg Med. 2005;46(5): Mountin D, Biley M, O Brien D, Jelinek GA. Blood cultures ordered in the dult emergency deprtment re rrely useful. 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The mngement of community-cquired pneumoni in infnts nd children older thn 3 months of ge: clinicl prctice guidelines by the editric Infectious Diseses Society nd the Infectious Diseses Society of Americ. Clin Infect Dis. 2011;53(7):e25 e VOLUME 3 ISSUE 2