A blood culture result comes back positive: What are your legal risks?
A blood culture result comes back positive: What are your legal risks?
It's a 'screening test nightmare' for EDs
A woman tells you she's had a headache for over a week and a history of diarrhea, and develops a fever during her ED stay. The headache resolves with non-narcotic interventions, and blood cultures are obtained. The patient's chest X-ray shows streaking. She is treated with parenteral ceftriaxone for presumed pneumonia, and discharged on doxycycline.
Four blood cultures come back positive, but when an ED nurse contacts the woman's husband, he says she's doing much better. Neither the ED nurse nor the physician asks the patient to return to the ED, and she returns two days later with altered mental status and partially treated meningitis. An adverse outcome results. Could your ED be sued?
"Blood cultures continue to be frequently drawn on ED patients, and often for good reason," says John Burton, MD, residency program director for the department of emergency medicine at Albany (NY) Medical Center. "However, this is a very problematic test from an ED perspective."
First, the results do not come back for 24 hours, and often are not finalized for up to 48 or 72 hours. "The patient is long gone from the ED at that point, of course," says Burton. "The yield of the tests are very low, with most published reports indicating true positive cultures in as low as 1% of patients to a high of around 9%."1-3
Burton adds that in most studies, positive results are just as likely to be false positive contaminants as they are true positives. "The bottom line is, it's a test that does not give immediate results, and is just as likely to give bad information as it is to give information that contributes to patient management," says Burton. "In short, it is a screening test nightmare, in my opinion, for an ED test."
Every positive blood culture should be reviewed by an ED physician, to see where the culture fits into the patient's clinical picture, says James R. Miner, MD, FACEP, associate professor of emergency medicine at University of Minnesota Medical School and faculty physician in the ED at Hennepin County Medical Center, both in Minneapolis. "Patients with a blood culture that isn't an obvious contaminant should be contacted immediately for follow up, hopefully with their primary care provider but in the ED if it can't be arranged," says Miner.
The difficult part of ordering a test that will not yield final results while the patient is in the ED is that the ordering physician is the one responsible for acting on the findings of the results, says Miner. "If a blood culture returns positive and a patient goes untreated, the physician who ordered the blood culture is responsible for not arranging appropriate treatment," he explains.
When should patients return?
Burton notes that in 12 years of doing medical– legal cases in seven different states, he hasn't seen a single case involving failure to contact a patient with a positive blood culture obtained in the ED.
"But, it's certainly a risk," Burton says. "The risk and prevalence of cases is likely much smaller because the majority of patients with positive cultures who are also initially discharged tend to do very well. This suggests that the sicker and higher-risk patients tend to get admitted for reasons independent of any information yielded from ED blood cultures."
If a patient with a positive culture doesn't return to the ED, risks include failure to administer appropriate antibiotic coverage to a patient with bacteremia. Edward Monico, MD, JD, assistant professor in the section of emergency medicine at Yale University School of Medicine in New Haven, CT, notes that microorganisms that always or nearly always represent true infection when isolated from blood cultures include Staphylococcus aureus, Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus pneumoniae, Escherichia coli, and other members of enterobacteriaceae, pseudomonas aeruginosa, the Bacteroides fragilis group, and the Candida species.
In contrast, coagulase-negative staphylococci, Corynebacterium species, Bacillus species other than B. anthracis, and Propionibacterium acnes usually represent contamination, says Monico. "Corynebacterium species are part of the normal human skin flora, so they typically do not cause true invasive disease," he says. "But Corynebacterium can cause clinically significant infections in the presence of medical devices such as joint prostheses, catheters, ports, vascular grafts, prosthetic heart valves, pacemakers, and implantable cardioverter defibrillators."
To notify your patient about a positive result, Burton says it is equally acceptable to contact either the patient or the primary care physician, provided that the doctor is familiar with the patient and agrees to assume responsibility for follow-up.
Whether the patient is on antibiotics as an outpatient is a factor that must be considered, as well, says Burton. However, if the patient is still having infectious disease symptoms that could be attributable to the culture, or is in a high-risk group such as an immunocompromised, elderly, or intravenous drug abuse patient, he or she should be asked to return immediately for reassessment.
"If the patient is in a high-risk group, is still having symptoms, or not on antibiotics, then the risk for not having them evaluated is substantial," says Burton. "If the answer to all these queries is in the negative, then the risk is relatively small."
According to Monico, since blood culture results do not return until the patient has been discharged from the ED, the responsible ED physician should have a strategy in place to assure the timely interpretation of these results.
Monico says that strategy should be, in the overwhelming majority of cases, to admit patients requiring blood cultures. "For the remaining few, the chart should clearly document who will be responsible for the interpretation of blood culture results in patients discharged from the ED," says Monico. "That person should be the primary care physician who agrees to accept this responsibility."
When to have the patient return to the ED is largely dependent on the context of the case, says Monico. "A positive result should be reviewed in light of the patient's chief complaint, comorbidities, ability to obtain timely follow up, and treatment rendered at the time the cultures were obtained," he says.
Make a good faith effort
Document all the efforts made to contact the patient, including phone calls to the patient's home or primary care physician's office, and certified letters sent to their mail address. "This is simply all that can be done. The ED should essentially document a 'reasonable good faith effort' to make this contact," says Burton.
Miner says that he usually makes three phone calls to the patient at different times of the day, then sends a letter asking the patient to return to the ED for reevaluation due to their positive blood culture.
How exhaustive an effort you make depends largely on your practice environment. "Policies are likely going to be different for an inner city, indigent population than a population that has a high prevalence of primary care doctors and reliable health network," says Burton.
If you reach the patient's primary care physician, document the time and content of that discussion. "This should reflect any conclusion the ED or primary care physician makes regarding whether the results represent infection or contamination and the shift of responsibility for patient follow-up," says Monico.
Monico says that your documentation should reflect the level of concern as to the likelihood of true infection versus contamination. "This documentation can involve phone calls to the patient, the patient's relatives, primary care physicians or, depending on the scenario, agencies such as the state board of health," he says.
"Risk stratify" a positive culture
Traditionally, blood cultures were typically performed in an ED only for certain types of patients suspected to have bacterial infections, notes Matthew Rice, MD, JD, FACEP, an ED physician with Northwest Emergency Physicians of TEAMHealth in Federal Way, WA. This group included young children with fevers of uncertain origin, the immunocompromised who might have an infectious process, and other patients who appeared to be septic, who often received blood cultures before receiving antibiotics.
However, Rice says blood cultures are now being performed in EDs more frequently, due to various recommendations in evaluating and treating patients.
One problem with this, says Rice, is that a significant percentage of blood cultures collected in EDs are interpreted as positive by the laboratory, when in fact the results are contaminants from the blood culture drawing process, such as the skin or equipment not having been cleaned properly.
Additionally, some positive cultures indicating bacteria growing in a patient's blood may not be relevant to a patient's clinical course. The patient, even if infected with the bacteria growing in a culture several days after the culture was obtained, may subsequently be well and may not need further treatment. "Thus, positive blood cultures must be assessed against other clinical information in order to provide the best care for each patient," says Rice.
Rice says that every positive blood culture should be assessed by an experienced clinician to "risk stratify" the culture result with the patient's original clinical information.
"In some cases, this may be enough information that further contact with the patient is not imperative," says Rice. In cases with uncertainty, however, the patient should be contacted to determine the necessity for a timely clinical re-evaluation.
If you don't have a follow-up process that is faithfully followed, you leave yourself open to the possibility that a patient may have a bacterial process going on that requires a specific treatment, warns Rice, that if left unattended will result in that person and possibly others suffering increased morbidity or mortality.
"From a risk perspective, a positive blood culture in a patient who is not appropriately treated because of a failure to appropriately follow up with the patient is often interpreted as negligence on the part of the treating physician an treating institution," says Rice. "It is particularly damaging evidence in risk cases when a known abnormality is not appropriately addressed."
References
1. Chalasani NP, Valdecanas ML, Gopal AK, et al. Clinical utility of blood cultures in adult patients with community-acquired pneumonia without defined underlying risks. Chest 1995;108:932-936.
2. Campbell SG, Marrie TJ, Anstey R. Utility of blood cultures in the management of adults with community acquired pneumonia discharged from the emergency department. Emerg Med J 2003;20: 521-523.
3. Corbo J, Friedman B, Bijur P, et al. Limited usefulness of initial blood cultures in community acquired pneumonia. Emerg Med J 2004;21:446-448.
Four blood cultures come back positive, but when an ED nurse contacts the woman's husband, he says she's doing much better. Neither the ED nurse nor the physician asks the patient to return to the ED, and she returns two days later with altered mental status and partially treated meningitis. An adverse outcome results. Could your ED be sued?Subscribe Now for Access
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