I read this article last year, and fell in love with it. Only could a study like this be done in Canada. Next time your medicine resident yells at you for not getting blood cultures in CAP, show them this. Unfortunately I can't c/p the full article (too many charts) but I got the abstract.

The contribution of blood cultures to the clinical management of adult patients admitted to the hospital with community-acquired pneumonia: a prospective observational study.
Campbell SG - Chest - 01-APR-2003; 123(4): 1142-50
From NIH/NLM MEDLINE


NLM Citation ID:
12684305 (PubMed)


Comment:


Chest. 2003 Apr;123(4):977-8
PubMed ID: 12684278

Full Source Title:
Chest

Publication Type:
Clinical Trial; Controlled Clinical Trial; Journal Article; Multicenter Study; Randomized Controlled Trial

Language:
English

Author Affiliation:
Department of Emergency Medicine, Dalhousie University, Halifax, NS, Canada. sgcampbe@is.dal.ca

Authors:
Campbell SG; Marrie TJ; Anstey R; Dickinson G; Ackroyd-Stolarz S

Abstract:
STUDY OBJECTIVE: To assess the clinical usefulness of blood cultures (BCs) in the management of patients hospitalized with community-acquired pneumonia (CAP). DESIGN: A prospective, observational study to investigate the contribution of BCs to the management and outcomes of adult patients presenting with CAP. SETTING: Nineteen Canadian hospitals. PATIENTS: Adults admitted to the hospital with CAP between January 1, 1998, and July 31, 1998. INTERVENTIONS: The courses of therapy in patients for whom BC results yielded organisms considered to be clinically significant were analyzed to determine whether the BCs had contributed to management or outcome. MEASUREMENTS AND RESULTS: Forty-three of 760 patients had significantly positive BC results. Patients with CAP who had BCs performed had a 1.97% chance (15 of 760 patients) of having a change of therapy directed by BC results. Patients in whom BCs yielded positive results had a 34.8% chance (15 of 43 patients) of having a change in therapy determined by BC results, and had a 58.1% chance (25 of 43 patients) of having a course of therapy contraindicated by BC results. Severity of illness, as measured by the pneumonia severity index, correlated poorly with the yield of BCs. BC results were positive in 8.0% of patients in risk classes I and II, 6.2% of patients in risk class III, 4.6% of patients in risk class IV, and 5.2% of patients in risk class V. CONCLUSION: BCs have limited usefulness in the routine management of patients admitted to the hospital with uncomplicated CAP.

Wow. That's EBM for your ass! :eek: I especially like this result: Forty-three of 760 patients had significantly positive BC results. Patients with CAP who had BCs performed had a 1.97% chance (15 of 760 patients) of having a change of therapy directed by BC results.

Of course, I'm under the impression that if one failed to obtain BCs (and since I'm assuming that BCs in CAP is a gold-standard) that this would open the physician up to attack, no? Please correct me if I'm wrong.

Not-yet-in-Med-School n00b

For simple CAP I would intuitively agree that BC aren't necessary. The problem, as you well know, is differentiating between the simple CAP requiring admission vs the potentially bacteremic/septic pt. upon initial evaluation. If I have a pt with a fever, cough/SOB etc who doesn't look particularly sick, I won't necessarily order BC when I order my initial work up in the ED. What about the nursing home gomer with a temp of 94 or 102 who is altered, tachypenic, and borderline hypotensive? If I ultimately find a source of pneumonia as the work up shakes out, I've already ordered the BC anyway and point is moot. (But the designation of CAP in a NH pt is not technically correct either). Also I guess that if you cover the usual suspects in CAP well, even if there is a concurrent bacteremia found, the finding is just incidental and therapy would be the same.

I haven't read the abstract yet but this is just my inital thought.

As far as medicine residents yelling at me. My feelings would be genuinely hurt if the medicine resident neglected to yell at me. That's one of the few simple pleasures they have in life. Why deny them?

Edin, are you guys using the PORT criteria? We are using it more here and it doesn't replace clinical judgement of course but it does give you a leg to stand on to not get cultures on the class 1s and 2s.

I think the tack the internal medicine residents would take is that the BC is not frequently positive but when it is it is reasonably likely to change your management (50 something % of treatments inappropriate, 30 something percent change in management). So for patients who need to be hospitalized for their CAP I would still think it is reasonable. For outpt. therapy I would avoid it.

Now where's the study on sputum cultures? That's the real headache.

sputum cultures in the ED?? your kidding right?


We just did a journal club on the futility, I mean utility, of blood cultures in CAP. I tend to agree wiht Edin. If hte patient does not appear septic, and its the run of the mill CAP with just mild hypoxia or something else, we don't routinely get blood cultures. however, if the patient is in the septic, or soon-to-be-septic arena, I send cultures.

I'll post the three articles we did when I am back home and not on vacation...


off to eat and be merry some more. :D

I get them if someone is very ill.

YOu would want to document MRSA or resistant pneumococcus in the blood.

How can you not at least get them, though? Just for that 2 in 100 chance.

How can you not at least get them, though? Just for that 2 in 100 chance.

There are cost issues to worry about, plus extra IV sticks, etc. It's not COMPLETELY benign, just mostly benign. Honestly if they were indicated it would be no big deal but when you have to go and re-stick the lady that the nurses took an hour to try to find an IV on and in whom you eventually placed an IV under ultrasound guidance, you really don't want to have to restick her unless necessary. So the goal is to try to increase your odds from 2 in 100.

Neat study. Now I'm sure some lawyer is already getting his argument ready... "But in spite of that 1.9% chance.... you NEGLECTED to get blood cultures?"

As for sputum culture... pretty useless unless you get the sputum via bronchoscopy.