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In the Literature
In This Edition
Literature at a Glance
A guide to this month’s studies
- Effect of restrictive antibiotic policies on dosing timeliness
- Desired consultation format and content
- Risk of cancer associated with CT imaging
- Bleeding, mortality with aspirin after peptic ulcer bleed
- Diagnosis of lung cancer after pneumonia
- Outcomes associated with hyponatremia
- Patient awareness, interest in inpatient medication list
- Monoclonal antibodies in C. difficile
Restrictive Antimicrobial Policy Delays Administration
Clinical question: Does the approval process for restricted on-formulary antimicrobials cause a significant delay in their administration?
Background: Widespread and often unwarranted, antimicrobial use in the hospital lends itself to the development of microbial resistance and increases overall costs. To curb such practices, many hospitals require subspecialty approval prior to dispensing select broad-spectrum antimicrobials. Though shown to improve outcomes, the impact of the approval process on the timeliness of antimicrobial administration remains to be seen.
Study design: Retrospective cohort study.
Setting: Tertiary-care university hospital.
Synopsis: The study included 3,251 inpatients with computerized orders for a “stat” first dose of any of 24 pre-selected, parenteral antimicrobials. Time lag (more than one hour, and more than two hours) to nursing documentation of drug administration was separately analyzed for restricted and unrestricted antimicrobials.
Delay of more than one hour was significantly higher for restricted antimicrobials with an odds ratio of 1.49 (95% CI; 1.23-1.82), while the odds ratio for a delay of more than two hours was 1.78 (95% CI, 1.39-2.21). Also, for restricted antimicrobials, the percentage of orders delayed for more than one hour was significantly different between daytime and nighttime (when the first dose was exempt from pre-approval) orders: 46.1% versus 38.8% (P<0.001). For unrestricted drugs, delay was uniform irrespective of time of day (36.4% of daytime and 36.6% of nighttime orders were delayed more than one hour). The effect of delay in drug administration on patient outcomes was not evaluated.
Though the approval process aims in part to affect resistance patterns and overall costs, this research highlights the need to minimize the delay in administration and probably skip the approval for the first dose in critically ill patients.
Bottom line: Antibiotic approval processes can delay their administration in hospitalized patients, but the effect of this delay on patient outcomes is not yet known.
Citation: Winters BD, Thiemann DR, Brotman DJ. Impact of a restrictive antimicrobial policy on the process and timing of antimicrobial administration. J Hosp Med. 2010;5(1):E41-45.
Physicians Uphold Tenets of Effective Consultation while Highlighting Some Newer Viewpoints
Clinical question: What key features of a consultation are most desirable for physicians?
Background: With new changes in healthcare delivery, the standardization offered by the electronic health record (EHR) system will undoubtedly be confronted by the heterogeneity of clinical consultations. Determination of the various characteristics considered essential for a consultation can help standardize the processes and improve the quality of communication.
Study design: Opinion surveys with a 16-question, Web-based questionnaire about inpatient consultations.
Setting: Four Minnesota teaching hospitals affiliated with the University of Minnesota.
Synopsis: This study surveyed 651 physicians, mostly from general medicine and pediatrics (30% in-training; 54% were more than five years out of training). The response rate to the survey was 50% (323). Responses were analyzed separately for physicians predominantly requesting consultations (requesters) and those predominantly providing them (consultants).
Regarding the consultation request, the majority of consultants preferred a precise consult question (94%), contact information of the ordering provider (68%), and the urgency of consultation (66%), with telephonic communication for emergent consults (75%). Responses were similar regardless of practice site, specialty, or experience.
Regarding the consultation, more requesters desired verbal communication over written advice alone: Sixty-six percent preferred to have the rationale of the recommendations explained. They also preferred a separate recommendations section (48%) with bulleted suggestions (69%) at the top or bottom of the note (74%). Emphasis was placed on specificity of drug names, dose, and duration of therapy (80%), along with alternative options (76%). Most requesters desired a clear “signoff” note when appropriate, with a follow-up plan (74%) or scheduled appointments (44%).
Bottom line: For consultations, the majority of physicians prefer an explanation of medical decision-making, a crisp recommendation section, and specific directions for follow-up.
Citation: Boulware DR, Dekarske AS, Filice GA. Physician preferences for elements of effective consultations. J Gen Intern Med. 2010;25(1):25-30.
CT Scanning Could Be Related to a Future Risk of Cancer at a Population Level
Clinical question: Does the accelerated use of CT scans increase the future risk for radiation-related cancer?
Background: Computed tomography (CT) has come through as a powerful diagnostic and interventional imaging modality at the cost of higher radiation exposures. The potential cancer risk is minimal at an individual level; however, CT technology is used in more than 70 million scans annually. This volume can translate into a significant number of future cancers in the population.
Study design: Indirect risk modeling based on CT scan frequencies and radiation risk models.
Synopsis: Annual frequencies of CT scans (age- and sex-specific) were extracted from insurance claims. The study included 57 million scans, of which 30% were performed in adults 35 to 54 years old. The majority of scans were in females (60%).
Age-specific cancer risk for each CT scan type was estimated through published radiation risk models and national surveys. The projected number of incident cancers per 10,000 scans was highest for chest or abdominal CT angiography (CTA) and whole-body CT. Incidence was higher for females.
The CT scan frequencies were combined with the cancer risk, and it was estimated that approximately 29,000 (95% UL, 15,000-45,000) future cancers could be related to the exposure from CT scans. Uncertainty limits (UL), an estimation of the total error of measurement, accounted for statistical and subjective uncertainties. The risk was dependent on the radiation dose (chest CTA) and frequency of use (abdomen/pelvis followed by chest and head). The most common cancers were lung, colon, and leukemia.
Two-thirds of the projected cancers were in females and attributable to the higher frequency of scans in women coupled with their dual risk of breast and lung cancer with chest radiation. The results provide potential study targets for risk-reduction efforts.
Bottom line: CTA of the chest, abdomen, or pelvis could be related to risk of future cancers, especially in middle-aged females.
Citation: Berrington de González A, Mahesh M, Kim KP, et al. Projected cancer risks from computed tomographic scans performed in the United States in 2007. Arch Intern Med. 2009;169(22):2071-2077.
Early Resumption of Low-Dose Aspirin after Peptic Ulcer Bleeding Might Be Beneficial
Clinical question: Is it safe to restart aspirin after acute gastrointestinal (GI) bleeding in patients with cardiovascular or cerebrovascular disease?
Background: The increasing cardiovascular burden in the aging population has indirectly increased aspirin-related peptic ulcer bleeding. Proton-pump inhibitors (PPI) have shown promise in reducing recurrent GI bleeding in non-aspirin-related cases. It is unclear if this protective effect applies to patients on aspirin and, if so, if aspirin resumption after endoscopic treatment is safe.
Study design: Parallel, randomized, placebo-controlled, noninferiority trial.
Setting: Single tertiary endoscopy center in Hong Kong.
Synopsis: One hundred fifty-six patients with aspirin-related peptic ulcer bleeding were selected for the study. After successful endoscopic treatment and 72 hours on pantoprazole infusion, the patients were started on oral pantoprazole for the duration of the study (eight weeks). Patients were equally randomized to receive low-dose aspirin (80 mg/d) or placebo. Primary outcome was recurrent bleeding within 30 days. Secondary outcomes included eight-week all-cause mortality, cause-specific mortality, and recurrence of cardiovascular events.
The aspirin group had a 50% higher risk of recurrent bleeding within 30 days compared with placebo (10.3% vs. 5.4%). However, for the secondary endpoints, aspirin had lower all-cause mortality (1.3% vs. 12.9%), which was not related to increased GI bleeding. On the other hand, discontinuation of aspirin and use of PPI in the placebo group did not prevent mortality related to GI complications.
The small numbers restrict interpretation of the mortality rates but offer support to the fact that the cardioprotective effects of aspirin outweigh its potential for GI bleeding. It is to be noted that these results cannot be extrapolated to higher doses of aspirin.
Bottom line: Early resumption of aspirin after successful treatment of peptic ulcer bleeding might increase the risk of rebleeding but potentially decreases overall mortality.
Citation: Sung JJ, Lau JY, Ching JY, et al. Continuation of low-dose aspirin therapy in peptic ulcer bleeding: a randomized trial. Ann Intern Med. 2010;152(1):1-9.
A Substantial Number of Elderly Patients with Pneumonia Have Pulmonary Malignancy
Clinical question: What is the incidence of, and risk factors for, diagnosis of lung cancer after discharge for pneumonia?
Background: Pneumonia-related admissions in elderly individuals have increased by nearly 20% during the past two decades. Based on the risk profile of this age group, many physicians recommend follow-up chest imaging after pneumonia to ensure resolution and exclude underlying malignancy. However, this practice is not backed by substantial evidence.
Study design: Retrospective cohort study from administrative databases of the VA system.
Setting: Veteran Affairs (VA) Health Care System.
Synopsis: More than 40,000 patients (older than 65, 98.1% male) hospitalized for pneumonia were included in the study. These patients had no pneumonia in the preceding year and did not carry a diagnosis of lung cancer. During the follow-up period of up to five years, a significant proportion (9.2%) of these patients were diagnosed with pulmonary malignancy.
Pertinent factors associated with increased risk of diagnosis included active tobacco use, COPD, and prior nonpulmonary malignancy. Interestingly, stroke, diabetes, dementia, and heart failure were associated with a lower risk of diagnosis, likely due to early mortality from these diseases prior to diagnosis of lung cancer.
Mean time to diagnosis was 297 days, with just 27% diagnosed within 30 days. On mortality analysis, 12.9% (n=5270) of the patients died within 30 days and 20.7% (n=8451) within 90 days. Thus, a period of surveillance of 30 to 90 days following pneumonia, especially in patients with risk factors, could be beneficial.
This study was limited due to the shortcomings of database analyses. Also, the predominantly male, elderly, veteran population restricts extrapolation to the general population.
Bottom line: Patients with risk factors for lung cancer might benefit from surveillance chest imaging after hospitalization for pneumonia to rule out an underlying malignancy.
Citation: Mortensen EM, Copeland LA, Pugh MJ, et al. Diagnosis of pulmonary malignancy after hospitalization for pneumonia. Am J Med. 2010:123(1):66-71.
Hospital-Associated Hyponatremia of Any Severity Adversely Impacts Mortality and Financial Metrics
Clinical question: Does hyponatremia during a hospitalization prophesize a worse outcome?
Study design: Retrospective cohort study from 2002-2007.
Setting: Urban academic medical center.
Synopsis: This study included 53,236 adults based on the presence of admission or subsequent hyponatremia (defined as [Na+] <138 mEq/L). The patients were classified as community-acquired (CAH=37.9%), hospital-aggravated (5.7%), or hospital-acquired hyponatremia (HAH=38.2%).
Across all subgroups, all types of hyponatremia were independently associated with worse primary outcomes, including an increase in hospital mortality (CAH 52%, HAH 66%), prolongation of hospital stay, and discharge to a facility. Also, for the same [Na+], HAH had significantly increased mortality compared with CAH. Though the elderly were more prone to develop hyponatremia, patients younger than 65 had worse outcomes.
The severity of hyponatremia prognosticated adverse outcomes. The liberal definition of hyponatremia, as opposed to the current standard of <135 mEq/L, explains the large numbers in prevalence. However, even mild hyponatremia (133 mEq/L to 137) was linked to poor outcomes (adjusted OR 1.34; CI 1.18-1.51).
The study weaknesses include the use of administrative codes to identify comorbidities, less applicability to outpatient setting, and lack of evaluation of outcomes postdischarge. However, the robust numbers do establish inpatient hyponatremia as a marker of worse outcomes.
Bottom line: Inpatient hyponatremia of any severity is a marker of increased mortality and excessive financial burden.
Citation: Wald R, Jaber BL, Price LL, Upadhyay A, Madias NE. Impact of hospital-associated hyponatremia on selected outcomes. Arch Intern Med. 2010;170(3):294-302.
Patients Lack Awareness and Prefer to Be Updated Regarding Their Inpatient Medications
Clinical question: Is patient knowledge of their medications deficient, and does this reflect a lack of desire to be involved in the medication reconciliation process?
Background: Medication errors remain a significant healthcare problem due to their potential to increase morbidity. For medication administration errors, apart from the dispensing pharmacist and the nurses, patients could be the final checkpoint to ensure medication safety. However, their awareness and enthusiasm to participate has not been adequately assessed in the literature.
Study design: A cross-sectional study using individual surveys to assess awareness and attitudes regarding inpatient medications.
Setting: Single tertiary-care academic teaching hospital.
Synopsis: Fifty cognitively intact adult patients were consented for the study. Of these, 54% provided an accurate recollection of their outpatient medications. When they were surveyed regarding inpatient medications, 96% omitted at least one medication, with the average of 6.8 medication omissions. This was noted to correlate with age >65 years. Also, 44% erroneously presumed they were on a medication while they were in the hospital, even though they weren’t.
When attitudes were surveyed, most of the patients would have preferred to get an inpatient medication list (78%) with the goal of improving their satisfaction (81%) and reducing errors (94%). Also, no association was found between patients’ errors of omission and their reported desire to be involved in the medication safety process.
This small study was limited to cognitively intact patients only. Also, the relatively younger age might cause an overestimation of patient interest in participation. However, the results highlight key medication reconciliation issues. Although patient involvement is desirable, a systematic program of educating them about their medications would be required to make their feedback effective and useful.
Bottom line: Healthy patients might be unaware of their exact hospital medications but prefer to be kept in the loop.
Citation: Cumbler E, Wald H, Kutner J. Lack of patient knowledge regarding hospital medications. J Hosp Med. 2010;5(2):83-86.
Monoclonal Antibodies against Clostridium difficile Toxins Prevent Recurrence
Clinical question: Are human monoclonal antibodies against C. difficile toxin A (CDA1) and B (CDB1) effective in preventing recurrence of C. diff infection (CDI)?
Background: Widespread use of antibiotics, coupled with the emergence of the hypervirulent (B1/NAP1/027) strain of C. diff, has altered the epidemiology of CDI. Even with effective treatment regimens, there is an escalation in severity, treatment failures, and recurrences. Antibodies against the C. diff toxins are being evaluated as the next frontier in treatment of CDI.
Study design: Phase 2 randomized, double-blind, placebo-controlled trial.
Setting: Thirty study centers in Canada and the U.S.
Synopsis: Two hundred patients with laboratory documented CDI on standard therapy with either metronidazole or vancomycin were randomized to receive a single IV infusion of combined monoclonal antibodies against CDA1 and CDB1 (n=101) or a normal saline placebo infusion (n=99). Patients were followed for 84 days with daily stool counts and intermittent blood samples for immunogenicity analysis.
The primary endpoint of recurrence of laboratory-proven C. diff diarrhea was significantly lower in the monoclonal antibody group (7% vs. 25% in placebo. 95% CI, 7-29; P <0.001). In a subgroup analysis of the epidemic BI/NAP1/027 strain, this favorable association persisted (8% vs. 32%). Recurrence in the antibody group was seen more in elderly patients hospitalized with a higher severity of underlying disease.
Secondary endpoints relating to the initial episode of CDI including treatment failure, severity of diarrhea, and duration to resolution were not significantly different between the two groups. Fewer accounts of serious adverse events were documented in the antibody group (18 patients vs. 28 patients in placebo, P=0.09), and immunogenicity was not detected in any patient.
Bottom line: Monoclonal antibody infusion against C. diff toxins reduces recurrence of infection, even with a hypervirulent (B1/NAP1/027) strain, without any significant adverse events.
Citation: Lowy I, Molrine DC, Leav BA, et al. Treatment with monoclonal antibodies against Clostridium difficile toxins. N Engl J Med. 2010; 362(3):197-205. TH
PEDIATRIC HM LITERATURE
By Mark Shen, MD
Rectal Colonization with S. aureus Associated with Skin Abscesses
Clinical question: Is rectal colonization with Staphylococcus aureus more strongly associated with staphylococcal skin abscesses than nasal colonization?
Background: Staphylococcal skin and soft tissue infections have dramatically increased in recent years. While increased rates of nasal colonization with S. aureus have also been noted, a strong association with skin infections in children has not been established. The relationship between staphylococcal colonization of other body sites and skin infection is unknown.
Study design: Prospective cohort study.
Setting: Tertiary-care hospital in Buffalo, N.Y.
Synopsis: Sixty children, 0 to 18 years of age, requiring surgical drainage of S. aureus skin abscesses and 90 children undergoing other surgical procedures were enrolled consecutively. Rectal, nasal, and abscess (if applicable) cultures were obtained on all patients. Enrollment ceased when notably different rates of rectal colonization were recorded.
Rectal cultures were significantly more likely to be positive in the abscess group than the control group (47% vs. 1%; P<0.0001), while rates of nasal colonization were similar (27% vs. 21%; P=0.44). Abscess isolates were identical to rectal isolates in 88% of cases and nasal isolates in 75% of cases.
Other findings included a 60% prevalence of methicillin-resistant S. aureus (MRSA) in the abscess group. Fifty-nine of the 60 abscess isolates contained Panton-Valentine leukocidin genes; 57 were pulsed-field type USA300; and all 60 contained the staphylococcal cassette chromosome mec type IVa.
Given this representative sample of community-associated staphylococcal disease, these findings suggest that a focus on nasal carriage of S. aureus might be misguided.
Bottom Line: Rectal colonization with S. aureus better predicts skin abscess isolate than nasal carriage.
Citation: Faden H, Lesse AJ, Trask J, et al. Importance of colonization site in the current epidemic of staphylococcal skin abscesses. Pediatrics. 2010;125(3):e618-e624.
In This Edition
Literature at a Glance
A guide to this month’s studies
- Effect of restrictive antibiotic policies on dosing timeliness
- Desired consultation format and content
- Risk of cancer associated with CT imaging
- Bleeding, mortality with aspirin after peptic ulcer bleed
- Diagnosis of lung cancer after pneumonia
- Outcomes associated with hyponatremia
- Patient awareness, interest in inpatient medication list
- Monoclonal antibodies in C. difficile
Restrictive Antimicrobial Policy Delays Administration
Clinical question: Does the approval process for restricted on-formulary antimicrobials cause a significant delay in their administration?
Background: Widespread and often unwarranted, antimicrobial use in the hospital lends itself to the development of microbial resistance and increases overall costs. To curb such practices, many hospitals require subspecialty approval prior to dispensing select broad-spectrum antimicrobials. Though shown to improve outcomes, the impact of the approval process on the timeliness of antimicrobial administration remains to be seen.
Study design: Retrospective cohort study.
Setting: Tertiary-care university hospital.
Synopsis: The study included 3,251 inpatients with computerized orders for a “stat” first dose of any of 24 pre-selected, parenteral antimicrobials. Time lag (more than one hour, and more than two hours) to nursing documentation of drug administration was separately analyzed for restricted and unrestricted antimicrobials.
Delay of more than one hour was significantly higher for restricted antimicrobials with an odds ratio of 1.49 (95% CI; 1.23-1.82), while the odds ratio for a delay of more than two hours was 1.78 (95% CI, 1.39-2.21). Also, for restricted antimicrobials, the percentage of orders delayed for more than one hour was significantly different between daytime and nighttime (when the first dose was exempt from pre-approval) orders: 46.1% versus 38.8% (P<0.001). For unrestricted drugs, delay was uniform irrespective of time of day (36.4% of daytime and 36.6% of nighttime orders were delayed more than one hour). The effect of delay in drug administration on patient outcomes was not evaluated.
Though the approval process aims in part to affect resistance patterns and overall costs, this research highlights the need to minimize the delay in administration and probably skip the approval for the first dose in critically ill patients.
Bottom line: Antibiotic approval processes can delay their administration in hospitalized patients, but the effect of this delay on patient outcomes is not yet known.
Citation: Winters BD, Thiemann DR, Brotman DJ. Impact of a restrictive antimicrobial policy on the process and timing of antimicrobial administration. J Hosp Med. 2010;5(1):E41-45.
Physicians Uphold Tenets of Effective Consultation while Highlighting Some Newer Viewpoints
Clinical question: What key features of a consultation are most desirable for physicians?
Background: With new changes in healthcare delivery, the standardization offered by the electronic health record (EHR) system will undoubtedly be confronted by the heterogeneity of clinical consultations. Determination of the various characteristics considered essential for a consultation can help standardize the processes and improve the quality of communication.
Study design: Opinion surveys with a 16-question, Web-based questionnaire about inpatient consultations.
Setting: Four Minnesota teaching hospitals affiliated with the University of Minnesota.
Synopsis: This study surveyed 651 physicians, mostly from general medicine and pediatrics (30% in-training; 54% were more than five years out of training). The response rate to the survey was 50% (323). Responses were analyzed separately for physicians predominantly requesting consultations (requesters) and those predominantly providing them (consultants).
Regarding the consultation request, the majority of consultants preferred a precise consult question (94%), contact information of the ordering provider (68%), and the urgency of consultation (66%), with telephonic communication for emergent consults (75%). Responses were similar regardless of practice site, specialty, or experience.
Regarding the consultation, more requesters desired verbal communication over written advice alone: Sixty-six percent preferred to have the rationale of the recommendations explained. They also preferred a separate recommendations section (48%) with bulleted suggestions (69%) at the top or bottom of the note (74%). Emphasis was placed on specificity of drug names, dose, and duration of therapy (80%), along with alternative options (76%). Most requesters desired a clear “signoff” note when appropriate, with a follow-up plan (74%) or scheduled appointments (44%).
Bottom line: For consultations, the majority of physicians prefer an explanation of medical decision-making, a crisp recommendation section, and specific directions for follow-up.
Citation: Boulware DR, Dekarske AS, Filice GA. Physician preferences for elements of effective consultations. J Gen Intern Med. 2010;25(1):25-30.
CT Scanning Could Be Related to a Future Risk of Cancer at a Population Level
Clinical question: Does the accelerated use of CT scans increase the future risk for radiation-related cancer?
Background: Computed tomography (CT) has come through as a powerful diagnostic and interventional imaging modality at the cost of higher radiation exposures. The potential cancer risk is minimal at an individual level; however, CT technology is used in more than 70 million scans annually. This volume can translate into a significant number of future cancers in the population.
Study design: Indirect risk modeling based on CT scan frequencies and radiation risk models.
Synopsis: Annual frequencies of CT scans (age- and sex-specific) were extracted from insurance claims. The study included 57 million scans, of which 30% were performed in adults 35 to 54 years old. The majority of scans were in females (60%).
Age-specific cancer risk for each CT scan type was estimated through published radiation risk models and national surveys. The projected number of incident cancers per 10,000 scans was highest for chest or abdominal CT angiography (CTA) and whole-body CT. Incidence was higher for females.
The CT scan frequencies were combined with the cancer risk, and it was estimated that approximately 29,000 (95% UL, 15,000-45,000) future cancers could be related to the exposure from CT scans. Uncertainty limits (UL), an estimation of the total error of measurement, accounted for statistical and subjective uncertainties. The risk was dependent on the radiation dose (chest CTA) and frequency of use (abdomen/pelvis followed by chest and head). The most common cancers were lung, colon, and leukemia.
Two-thirds of the projected cancers were in females and attributable to the higher frequency of scans in women coupled with their dual risk of breast and lung cancer with chest radiation. The results provide potential study targets for risk-reduction efforts.
Bottom line: CTA of the chest, abdomen, or pelvis could be related to risk of future cancers, especially in middle-aged females.
Citation: Berrington de González A, Mahesh M, Kim KP, et al. Projected cancer risks from computed tomographic scans performed in the United States in 2007. Arch Intern Med. 2009;169(22):2071-2077.
Early Resumption of Low-Dose Aspirin after Peptic Ulcer Bleeding Might Be Beneficial
Clinical question: Is it safe to restart aspirin after acute gastrointestinal (GI) bleeding in patients with cardiovascular or cerebrovascular disease?
Background: The increasing cardiovascular burden in the aging population has indirectly increased aspirin-related peptic ulcer bleeding. Proton-pump inhibitors (PPI) have shown promise in reducing recurrent GI bleeding in non-aspirin-related cases. It is unclear if this protective effect applies to patients on aspirin and, if so, if aspirin resumption after endoscopic treatment is safe.
Study design: Parallel, randomized, placebo-controlled, noninferiority trial.
Setting: Single tertiary endoscopy center in Hong Kong.
Synopsis: One hundred fifty-six patients with aspirin-related peptic ulcer bleeding were selected for the study. After successful endoscopic treatment and 72 hours on pantoprazole infusion, the patients were started on oral pantoprazole for the duration of the study (eight weeks). Patients were equally randomized to receive low-dose aspirin (80 mg/d) or placebo. Primary outcome was recurrent bleeding within 30 days. Secondary outcomes included eight-week all-cause mortality, cause-specific mortality, and recurrence of cardiovascular events.
The aspirin group had a 50% higher risk of recurrent bleeding within 30 days compared with placebo (10.3% vs. 5.4%). However, for the secondary endpoints, aspirin had lower all-cause mortality (1.3% vs. 12.9%), which was not related to increased GI bleeding. On the other hand, discontinuation of aspirin and use of PPI in the placebo group did not prevent mortality related to GI complications.
The small numbers restrict interpretation of the mortality rates but offer support to the fact that the cardioprotective effects of aspirin outweigh its potential for GI bleeding. It is to be noted that these results cannot be extrapolated to higher doses of aspirin.
Bottom line: Early resumption of aspirin after successful treatment of peptic ulcer bleeding might increase the risk of rebleeding but potentially decreases overall mortality.
Citation: Sung JJ, Lau JY, Ching JY, et al. Continuation of low-dose aspirin therapy in peptic ulcer bleeding: a randomized trial. Ann Intern Med. 2010;152(1):1-9.
A Substantial Number of Elderly Patients with Pneumonia Have Pulmonary Malignancy
Clinical question: What is the incidence of, and risk factors for, diagnosis of lung cancer after discharge for pneumonia?
Background: Pneumonia-related admissions in elderly individuals have increased by nearly 20% during the past two decades. Based on the risk profile of this age group, many physicians recommend follow-up chest imaging after pneumonia to ensure resolution and exclude underlying malignancy. However, this practice is not backed by substantial evidence.
Study design: Retrospective cohort study from administrative databases of the VA system.
Setting: Veteran Affairs (VA) Health Care System.
Synopsis: More than 40,000 patients (older than 65, 98.1% male) hospitalized for pneumonia were included in the study. These patients had no pneumonia in the preceding year and did not carry a diagnosis of lung cancer. During the follow-up period of up to five years, a significant proportion (9.2%) of these patients were diagnosed with pulmonary malignancy.
Pertinent factors associated with increased risk of diagnosis included active tobacco use, COPD, and prior nonpulmonary malignancy. Interestingly, stroke, diabetes, dementia, and heart failure were associated with a lower risk of diagnosis, likely due to early mortality from these diseases prior to diagnosis of lung cancer.
Mean time to diagnosis was 297 days, with just 27% diagnosed within 30 days. On mortality analysis, 12.9% (n=5270) of the patients died within 30 days and 20.7% (n=8451) within 90 days. Thus, a period of surveillance of 30 to 90 days following pneumonia, especially in patients with risk factors, could be beneficial.
This study was limited due to the shortcomings of database analyses. Also, the predominantly male, elderly, veteran population restricts extrapolation to the general population.
Bottom line: Patients with risk factors for lung cancer might benefit from surveillance chest imaging after hospitalization for pneumonia to rule out an underlying malignancy.
Citation: Mortensen EM, Copeland LA, Pugh MJ, et al. Diagnosis of pulmonary malignancy after hospitalization for pneumonia. Am J Med. 2010:123(1):66-71.
Hospital-Associated Hyponatremia of Any Severity Adversely Impacts Mortality and Financial Metrics
Clinical question: Does hyponatremia during a hospitalization prophesize a worse outcome?
Study design: Retrospective cohort study from 2002-2007.
Setting: Urban academic medical center.
Synopsis: This study included 53,236 adults based on the presence of admission or subsequent hyponatremia (defined as [Na+] <138 mEq/L). The patients were classified as community-acquired (CAH=37.9%), hospital-aggravated (5.7%), or hospital-acquired hyponatremia (HAH=38.2%).
Across all subgroups, all types of hyponatremia were independently associated with worse primary outcomes, including an increase in hospital mortality (CAH 52%, HAH 66%), prolongation of hospital stay, and discharge to a facility. Also, for the same [Na+], HAH had significantly increased mortality compared with CAH. Though the elderly were more prone to develop hyponatremia, patients younger than 65 had worse outcomes.
The severity of hyponatremia prognosticated adverse outcomes. The liberal definition of hyponatremia, as opposed to the current standard of <135 mEq/L, explains the large numbers in prevalence. However, even mild hyponatremia (133 mEq/L to 137) was linked to poor outcomes (adjusted OR 1.34; CI 1.18-1.51).
The study weaknesses include the use of administrative codes to identify comorbidities, less applicability to outpatient setting, and lack of evaluation of outcomes postdischarge. However, the robust numbers do establish inpatient hyponatremia as a marker of worse outcomes.
Bottom line: Inpatient hyponatremia of any severity is a marker of increased mortality and excessive financial burden.
Citation: Wald R, Jaber BL, Price LL, Upadhyay A, Madias NE. Impact of hospital-associated hyponatremia on selected outcomes. Arch Intern Med. 2010;170(3):294-302.
Patients Lack Awareness and Prefer to Be Updated Regarding Their Inpatient Medications
Clinical question: Is patient knowledge of their medications deficient, and does this reflect a lack of desire to be involved in the medication reconciliation process?
Background: Medication errors remain a significant healthcare problem due to their potential to increase morbidity. For medication administration errors, apart from the dispensing pharmacist and the nurses, patients could be the final checkpoint to ensure medication safety. However, their awareness and enthusiasm to participate has not been adequately assessed in the literature.
Study design: A cross-sectional study using individual surveys to assess awareness and attitudes regarding inpatient medications.
Setting: Single tertiary-care academic teaching hospital.
Synopsis: Fifty cognitively intact adult patients were consented for the study. Of these, 54% provided an accurate recollection of their outpatient medications. When they were surveyed regarding inpatient medications, 96% omitted at least one medication, with the average of 6.8 medication omissions. This was noted to correlate with age >65 years. Also, 44% erroneously presumed they were on a medication while they were in the hospital, even though they weren’t.
When attitudes were surveyed, most of the patients would have preferred to get an inpatient medication list (78%) with the goal of improving their satisfaction (81%) and reducing errors (94%). Also, no association was found between patients’ errors of omission and their reported desire to be involved in the medication safety process.
This small study was limited to cognitively intact patients only. Also, the relatively younger age might cause an overestimation of patient interest in participation. However, the results highlight key medication reconciliation issues. Although patient involvement is desirable, a systematic program of educating them about their medications would be required to make their feedback effective and useful.
Bottom line: Healthy patients might be unaware of their exact hospital medications but prefer to be kept in the loop.
Citation: Cumbler E, Wald H, Kutner J. Lack of patient knowledge regarding hospital medications. J Hosp Med. 2010;5(2):83-86.
Monoclonal Antibodies against Clostridium difficile Toxins Prevent Recurrence
Clinical question: Are human monoclonal antibodies against C. difficile toxin A (CDA1) and B (CDB1) effective in preventing recurrence of C. diff infection (CDI)?
Background: Widespread use of antibiotics, coupled with the emergence of the hypervirulent (B1/NAP1/027) strain of C. diff, has altered the epidemiology of CDI. Even with effective treatment regimens, there is an escalation in severity, treatment failures, and recurrences. Antibodies against the C. diff toxins are being evaluated as the next frontier in treatment of CDI.
Study design: Phase 2 randomized, double-blind, placebo-controlled trial.
Setting: Thirty study centers in Canada and the U.S.
Synopsis: Two hundred patients with laboratory documented CDI on standard therapy with either metronidazole or vancomycin were randomized to receive a single IV infusion of combined monoclonal antibodies against CDA1 and CDB1 (n=101) or a normal saline placebo infusion (n=99). Patients were followed for 84 days with daily stool counts and intermittent blood samples for immunogenicity analysis.
The primary endpoint of recurrence of laboratory-proven C. diff diarrhea was significantly lower in the monoclonal antibody group (7% vs. 25% in placebo. 95% CI, 7-29; P <0.001). In a subgroup analysis of the epidemic BI/NAP1/027 strain, this favorable association persisted (8% vs. 32%). Recurrence in the antibody group was seen more in elderly patients hospitalized with a higher severity of underlying disease.
Secondary endpoints relating to the initial episode of CDI including treatment failure, severity of diarrhea, and duration to resolution were not significantly different between the two groups. Fewer accounts of serious adverse events were documented in the antibody group (18 patients vs. 28 patients in placebo, P=0.09), and immunogenicity was not detected in any patient.
Bottom line: Monoclonal antibody infusion against C. diff toxins reduces recurrence of infection, even with a hypervirulent (B1/NAP1/027) strain, without any significant adverse events.
Citation: Lowy I, Molrine DC, Leav BA, et al. Treatment with monoclonal antibodies against Clostridium difficile toxins. N Engl J Med. 2010; 362(3):197-205. TH
PEDIATRIC HM LITERATURE
By Mark Shen, MD
Rectal Colonization with S. aureus Associated with Skin Abscesses
Clinical question: Is rectal colonization with Staphylococcus aureus more strongly associated with staphylococcal skin abscesses than nasal colonization?
Background: Staphylococcal skin and soft tissue infections have dramatically increased in recent years. While increased rates of nasal colonization with S. aureus have also been noted, a strong association with skin infections in children has not been established. The relationship between staphylococcal colonization of other body sites and skin infection is unknown.
Study design: Prospective cohort study.
Setting: Tertiary-care hospital in Buffalo, N.Y.
Synopsis: Sixty children, 0 to 18 years of age, requiring surgical drainage of S. aureus skin abscesses and 90 children undergoing other surgical procedures were enrolled consecutively. Rectal, nasal, and abscess (if applicable) cultures were obtained on all patients. Enrollment ceased when notably different rates of rectal colonization were recorded.
Rectal cultures were significantly more likely to be positive in the abscess group than the control group (47% vs. 1%; P<0.0001), while rates of nasal colonization were similar (27% vs. 21%; P=0.44). Abscess isolates were identical to rectal isolates in 88% of cases and nasal isolates in 75% of cases.
Other findings included a 60% prevalence of methicillin-resistant S. aureus (MRSA) in the abscess group. Fifty-nine of the 60 abscess isolates contained Panton-Valentine leukocidin genes; 57 were pulsed-field type USA300; and all 60 contained the staphylococcal cassette chromosome mec type IVa.
Given this representative sample of community-associated staphylococcal disease, these findings suggest that a focus on nasal carriage of S. aureus might be misguided.
Bottom Line: Rectal colonization with S. aureus better predicts skin abscess isolate than nasal carriage.
Citation: Faden H, Lesse AJ, Trask J, et al. Importance of colonization site in the current epidemic of staphylococcal skin abscesses. Pediatrics. 2010;125(3):e618-e624.
In This Edition
Literature at a Glance
A guide to this month’s studies
- Effect of restrictive antibiotic policies on dosing timeliness
- Desired consultation format and content
- Risk of cancer associated with CT imaging
- Bleeding, mortality with aspirin after peptic ulcer bleed
- Diagnosis of lung cancer after pneumonia
- Outcomes associated with hyponatremia
- Patient awareness, interest in inpatient medication list
- Monoclonal antibodies in C. difficile
Restrictive Antimicrobial Policy Delays Administration
Clinical question: Does the approval process for restricted on-formulary antimicrobials cause a significant delay in their administration?
Background: Widespread and often unwarranted, antimicrobial use in the hospital lends itself to the development of microbial resistance and increases overall costs. To curb such practices, many hospitals require subspecialty approval prior to dispensing select broad-spectrum antimicrobials. Though shown to improve outcomes, the impact of the approval process on the timeliness of antimicrobial administration remains to be seen.
Study design: Retrospective cohort study.
Setting: Tertiary-care university hospital.
Synopsis: The study included 3,251 inpatients with computerized orders for a “stat” first dose of any of 24 pre-selected, parenteral antimicrobials. Time lag (more than one hour, and more than two hours) to nursing documentation of drug administration was separately analyzed for restricted and unrestricted antimicrobials.
Delay of more than one hour was significantly higher for restricted antimicrobials with an odds ratio of 1.49 (95% CI; 1.23-1.82), while the odds ratio for a delay of more than two hours was 1.78 (95% CI, 1.39-2.21). Also, for restricted antimicrobials, the percentage of orders delayed for more than one hour was significantly different between daytime and nighttime (when the first dose was exempt from pre-approval) orders: 46.1% versus 38.8% (P<0.001). For unrestricted drugs, delay was uniform irrespective of time of day (36.4% of daytime and 36.6% of nighttime orders were delayed more than one hour). The effect of delay in drug administration on patient outcomes was not evaluated.
Though the approval process aims in part to affect resistance patterns and overall costs, this research highlights the need to minimize the delay in administration and probably skip the approval for the first dose in critically ill patients.
Bottom line: Antibiotic approval processes can delay their administration in hospitalized patients, but the effect of this delay on patient outcomes is not yet known.
Citation: Winters BD, Thiemann DR, Brotman DJ. Impact of a restrictive antimicrobial policy on the process and timing of antimicrobial administration. J Hosp Med. 2010;5(1):E41-45.
Physicians Uphold Tenets of Effective Consultation while Highlighting Some Newer Viewpoints
Clinical question: What key features of a consultation are most desirable for physicians?
Background: With new changes in healthcare delivery, the standardization offered by the electronic health record (EHR) system will undoubtedly be confronted by the heterogeneity of clinical consultations. Determination of the various characteristics considered essential for a consultation can help standardize the processes and improve the quality of communication.
Study design: Opinion surveys with a 16-question, Web-based questionnaire about inpatient consultations.
Setting: Four Minnesota teaching hospitals affiliated with the University of Minnesota.
Synopsis: This study surveyed 651 physicians, mostly from general medicine and pediatrics (30% in-training; 54% were more than five years out of training). The response rate to the survey was 50% (323). Responses were analyzed separately for physicians predominantly requesting consultations (requesters) and those predominantly providing them (consultants).
Regarding the consultation request, the majority of consultants preferred a precise consult question (94%), contact information of the ordering provider (68%), and the urgency of consultation (66%), with telephonic communication for emergent consults (75%). Responses were similar regardless of practice site, specialty, or experience.
Regarding the consultation, more requesters desired verbal communication over written advice alone: Sixty-six percent preferred to have the rationale of the recommendations explained. They also preferred a separate recommendations section (48%) with bulleted suggestions (69%) at the top or bottom of the note (74%). Emphasis was placed on specificity of drug names, dose, and duration of therapy (80%), along with alternative options (76%). Most requesters desired a clear “signoff” note when appropriate, with a follow-up plan (74%) or scheduled appointments (44%).
Bottom line: For consultations, the majority of physicians prefer an explanation of medical decision-making, a crisp recommendation section, and specific directions for follow-up.
Citation: Boulware DR, Dekarske AS, Filice GA. Physician preferences for elements of effective consultations. J Gen Intern Med. 2010;25(1):25-30.
CT Scanning Could Be Related to a Future Risk of Cancer at a Population Level
Clinical question: Does the accelerated use of CT scans increase the future risk for radiation-related cancer?
Background: Computed tomography (CT) has come through as a powerful diagnostic and interventional imaging modality at the cost of higher radiation exposures. The potential cancer risk is minimal at an individual level; however, CT technology is used in more than 70 million scans annually. This volume can translate into a significant number of future cancers in the population.
Study design: Indirect risk modeling based on CT scan frequencies and radiation risk models.
Synopsis: Annual frequencies of CT scans (age- and sex-specific) were extracted from insurance claims. The study included 57 million scans, of which 30% were performed in adults 35 to 54 years old. The majority of scans were in females (60%).
Age-specific cancer risk for each CT scan type was estimated through published radiation risk models and national surveys. The projected number of incident cancers per 10,000 scans was highest for chest or abdominal CT angiography (CTA) and whole-body CT. Incidence was higher for females.
The CT scan frequencies were combined with the cancer risk, and it was estimated that approximately 29,000 (95% UL, 15,000-45,000) future cancers could be related to the exposure from CT scans. Uncertainty limits (UL), an estimation of the total error of measurement, accounted for statistical and subjective uncertainties. The risk was dependent on the radiation dose (chest CTA) and frequency of use (abdomen/pelvis followed by chest and head). The most common cancers were lung, colon, and leukemia.
Two-thirds of the projected cancers were in females and attributable to the higher frequency of scans in women coupled with their dual risk of breast and lung cancer with chest radiation. The results provide potential study targets for risk-reduction efforts.
Bottom line: CTA of the chest, abdomen, or pelvis could be related to risk of future cancers, especially in middle-aged females.
Citation: Berrington de González A, Mahesh M, Kim KP, et al. Projected cancer risks from computed tomographic scans performed in the United States in 2007. Arch Intern Med. 2009;169(22):2071-2077.
Early Resumption of Low-Dose Aspirin after Peptic Ulcer Bleeding Might Be Beneficial
Clinical question: Is it safe to restart aspirin after acute gastrointestinal (GI) bleeding in patients with cardiovascular or cerebrovascular disease?
Background: The increasing cardiovascular burden in the aging population has indirectly increased aspirin-related peptic ulcer bleeding. Proton-pump inhibitors (PPI) have shown promise in reducing recurrent GI bleeding in non-aspirin-related cases. It is unclear if this protective effect applies to patients on aspirin and, if so, if aspirin resumption after endoscopic treatment is safe.
Study design: Parallel, randomized, placebo-controlled, noninferiority trial.
Setting: Single tertiary endoscopy center in Hong Kong.
Synopsis: One hundred fifty-six patients with aspirin-related peptic ulcer bleeding were selected for the study. After successful endoscopic treatment and 72 hours on pantoprazole infusion, the patients were started on oral pantoprazole for the duration of the study (eight weeks). Patients were equally randomized to receive low-dose aspirin (80 mg/d) or placebo. Primary outcome was recurrent bleeding within 30 days. Secondary outcomes included eight-week all-cause mortality, cause-specific mortality, and recurrence of cardiovascular events.
The aspirin group had a 50% higher risk of recurrent bleeding within 30 days compared with placebo (10.3% vs. 5.4%). However, for the secondary endpoints, aspirin had lower all-cause mortality (1.3% vs. 12.9%), which was not related to increased GI bleeding. On the other hand, discontinuation of aspirin and use of PPI in the placebo group did not prevent mortality related to GI complications.
The small numbers restrict interpretation of the mortality rates but offer support to the fact that the cardioprotective effects of aspirin outweigh its potential for GI bleeding. It is to be noted that these results cannot be extrapolated to higher doses of aspirin.
Bottom line: Early resumption of aspirin after successful treatment of peptic ulcer bleeding might increase the risk of rebleeding but potentially decreases overall mortality.
Citation: Sung JJ, Lau JY, Ching JY, et al. Continuation of low-dose aspirin therapy in peptic ulcer bleeding: a randomized trial. Ann Intern Med. 2010;152(1):1-9.
A Substantial Number of Elderly Patients with Pneumonia Have Pulmonary Malignancy
Clinical question: What is the incidence of, and risk factors for, diagnosis of lung cancer after discharge for pneumonia?
Background: Pneumonia-related admissions in elderly individuals have increased by nearly 20% during the past two decades. Based on the risk profile of this age group, many physicians recommend follow-up chest imaging after pneumonia to ensure resolution and exclude underlying malignancy. However, this practice is not backed by substantial evidence.
Study design: Retrospective cohort study from administrative databases of the VA system.
Setting: Veteran Affairs (VA) Health Care System.
Synopsis: More than 40,000 patients (older than 65, 98.1% male) hospitalized for pneumonia were included in the study. These patients had no pneumonia in the preceding year and did not carry a diagnosis of lung cancer. During the follow-up period of up to five years, a significant proportion (9.2%) of these patients were diagnosed with pulmonary malignancy.
Pertinent factors associated with increased risk of diagnosis included active tobacco use, COPD, and prior nonpulmonary malignancy. Interestingly, stroke, diabetes, dementia, and heart failure were associated with a lower risk of diagnosis, likely due to early mortality from these diseases prior to diagnosis of lung cancer.
Mean time to diagnosis was 297 days, with just 27% diagnosed within 30 days. On mortality analysis, 12.9% (n=5270) of the patients died within 30 days and 20.7% (n=8451) within 90 days. Thus, a period of surveillance of 30 to 90 days following pneumonia, especially in patients with risk factors, could be beneficial.
This study was limited due to the shortcomings of database analyses. Also, the predominantly male, elderly, veteran population restricts extrapolation to the general population.
Bottom line: Patients with risk factors for lung cancer might benefit from surveillance chest imaging after hospitalization for pneumonia to rule out an underlying malignancy.
Citation: Mortensen EM, Copeland LA, Pugh MJ, et al. Diagnosis of pulmonary malignancy after hospitalization for pneumonia. Am J Med. 2010:123(1):66-71.
Hospital-Associated Hyponatremia of Any Severity Adversely Impacts Mortality and Financial Metrics
Clinical question: Does hyponatremia during a hospitalization prophesize a worse outcome?
Study design: Retrospective cohort study from 2002-2007.
Setting: Urban academic medical center.
Synopsis: This study included 53,236 adults based on the presence of admission or subsequent hyponatremia (defined as [Na+] <138 mEq/L). The patients were classified as community-acquired (CAH=37.9%), hospital-aggravated (5.7%), or hospital-acquired hyponatremia (HAH=38.2%).
Across all subgroups, all types of hyponatremia were independently associated with worse primary outcomes, including an increase in hospital mortality (CAH 52%, HAH 66%), prolongation of hospital stay, and discharge to a facility. Also, for the same [Na+], HAH had significantly increased mortality compared with CAH. Though the elderly were more prone to develop hyponatremia, patients younger than 65 had worse outcomes.
The severity of hyponatremia prognosticated adverse outcomes. The liberal definition of hyponatremia, as opposed to the current standard of <135 mEq/L, explains the large numbers in prevalence. However, even mild hyponatremia (133 mEq/L to 137) was linked to poor outcomes (adjusted OR 1.34; CI 1.18-1.51).
The study weaknesses include the use of administrative codes to identify comorbidities, less applicability to outpatient setting, and lack of evaluation of outcomes postdischarge. However, the robust numbers do establish inpatient hyponatremia as a marker of worse outcomes.
Bottom line: Inpatient hyponatremia of any severity is a marker of increased mortality and excessive financial burden.
Citation: Wald R, Jaber BL, Price LL, Upadhyay A, Madias NE. Impact of hospital-associated hyponatremia on selected outcomes. Arch Intern Med. 2010;170(3):294-302.
Patients Lack Awareness and Prefer to Be Updated Regarding Their Inpatient Medications
Clinical question: Is patient knowledge of their medications deficient, and does this reflect a lack of desire to be involved in the medication reconciliation process?
Background: Medication errors remain a significant healthcare problem due to their potential to increase morbidity. For medication administration errors, apart from the dispensing pharmacist and the nurses, patients could be the final checkpoint to ensure medication safety. However, their awareness and enthusiasm to participate has not been adequately assessed in the literature.
Study design: A cross-sectional study using individual surveys to assess awareness and attitudes regarding inpatient medications.
Setting: Single tertiary-care academic teaching hospital.
Synopsis: Fifty cognitively intact adult patients were consented for the study. Of these, 54% provided an accurate recollection of their outpatient medications. When they were surveyed regarding inpatient medications, 96% omitted at least one medication, with the average of 6.8 medication omissions. This was noted to correlate with age >65 years. Also, 44% erroneously presumed they were on a medication while they were in the hospital, even though they weren’t.
When attitudes were surveyed, most of the patients would have preferred to get an inpatient medication list (78%) with the goal of improving their satisfaction (81%) and reducing errors (94%). Also, no association was found between patients’ errors of omission and their reported desire to be involved in the medication safety process.
This small study was limited to cognitively intact patients only. Also, the relatively younger age might cause an overestimation of patient interest in participation. However, the results highlight key medication reconciliation issues. Although patient involvement is desirable, a systematic program of educating them about their medications would be required to make their feedback effective and useful.
Bottom line: Healthy patients might be unaware of their exact hospital medications but prefer to be kept in the loop.
Citation: Cumbler E, Wald H, Kutner J. Lack of patient knowledge regarding hospital medications. J Hosp Med. 2010;5(2):83-86.
Monoclonal Antibodies against Clostridium difficile Toxins Prevent Recurrence
Clinical question: Are human monoclonal antibodies against C. difficile toxin A (CDA1) and B (CDB1) effective in preventing recurrence of C. diff infection (CDI)?
Background: Widespread use of antibiotics, coupled with the emergence of the hypervirulent (B1/NAP1/027) strain of C. diff, has altered the epidemiology of CDI. Even with effective treatment regimens, there is an escalation in severity, treatment failures, and recurrences. Antibodies against the C. diff toxins are being evaluated as the next frontier in treatment of CDI.
Study design: Phase 2 randomized, double-blind, placebo-controlled trial.
Setting: Thirty study centers in Canada and the U.S.
Synopsis: Two hundred patients with laboratory documented CDI on standard therapy with either metronidazole or vancomycin were randomized to receive a single IV infusion of combined monoclonal antibodies against CDA1 and CDB1 (n=101) or a normal saline placebo infusion (n=99). Patients were followed for 84 days with daily stool counts and intermittent blood samples for immunogenicity analysis.
The primary endpoint of recurrence of laboratory-proven C. diff diarrhea was significantly lower in the monoclonal antibody group (7% vs. 25% in placebo. 95% CI, 7-29; P <0.001). In a subgroup analysis of the epidemic BI/NAP1/027 strain, this favorable association persisted (8% vs. 32%). Recurrence in the antibody group was seen more in elderly patients hospitalized with a higher severity of underlying disease.
Secondary endpoints relating to the initial episode of CDI including treatment failure, severity of diarrhea, and duration to resolution were not significantly different between the two groups. Fewer accounts of serious adverse events were documented in the antibody group (18 patients vs. 28 patients in placebo, P=0.09), and immunogenicity was not detected in any patient.
Bottom line: Monoclonal antibody infusion against C. diff toxins reduces recurrence of infection, even with a hypervirulent (B1/NAP1/027) strain, without any significant adverse events.
Citation: Lowy I, Molrine DC, Leav BA, et al. Treatment with monoclonal antibodies against Clostridium difficile toxins. N Engl J Med. 2010; 362(3):197-205. TH
PEDIATRIC HM LITERATURE
By Mark Shen, MD
Rectal Colonization with S. aureus Associated with Skin Abscesses
Clinical question: Is rectal colonization with Staphylococcus aureus more strongly associated with staphylococcal skin abscesses than nasal colonization?
Background: Staphylococcal skin and soft tissue infections have dramatically increased in recent years. While increased rates of nasal colonization with S. aureus have also been noted, a strong association with skin infections in children has not been established. The relationship between staphylococcal colonization of other body sites and skin infection is unknown.
Study design: Prospective cohort study.
Setting: Tertiary-care hospital in Buffalo, N.Y.
Synopsis: Sixty children, 0 to 18 years of age, requiring surgical drainage of S. aureus skin abscesses and 90 children undergoing other surgical procedures were enrolled consecutively. Rectal, nasal, and abscess (if applicable) cultures were obtained on all patients. Enrollment ceased when notably different rates of rectal colonization were recorded.
Rectal cultures were significantly more likely to be positive in the abscess group than the control group (47% vs. 1%; P<0.0001), while rates of nasal colonization were similar (27% vs. 21%; P=0.44). Abscess isolates were identical to rectal isolates in 88% of cases and nasal isolates in 75% of cases.
Other findings included a 60% prevalence of methicillin-resistant S. aureus (MRSA) in the abscess group. Fifty-nine of the 60 abscess isolates contained Panton-Valentine leukocidin genes; 57 were pulsed-field type USA300; and all 60 contained the staphylococcal cassette chromosome mec type IVa.
Given this representative sample of community-associated staphylococcal disease, these findings suggest that a focus on nasal carriage of S. aureus might be misguided.
Bottom Line: Rectal colonization with S. aureus better predicts skin abscess isolate than nasal carriage.
Citation: Faden H, Lesse AJ, Trask J, et al. Importance of colonization site in the current epidemic of staphylococcal skin abscesses. Pediatrics. 2010;125(3):e618-e624.