P&T News: January/February 2003
Krysten Modrzejewski, Pharm.D., Specialized Resident, Drug
Information/Pharmaceutical Informatics, Department of Pharmaceutical
Care and College of Pharmacy.
Peer Review Status: Internally Peer Reviewed by
Douglas B. Hornick, M.D., Professor, Division of Pulmonary, Critical
Care, and Pulmonary Medicine and Raymond Todd Wiblin, M.D., Assistant
Professor, Division of General Medicine, Department of Internal
Medicine
The diagnosis of community-acquired pneumonia (CAP) carries with it substantial morbidity and mortality. Approximately 600,000 patients annually are hospitalized due to pneumonia at a cost of $23 billion,1,2 and pneumonia is the sixth leading cause of death overall in the United States.3
Well-established guidelines are aimed at reducing morbidity and mortality, as well as variations in the clinical management of CAP.4 At UIHC process-of-care variables such as appropriate antibiotic selection, time to antibiotic administration and switch from IV to oral therapy are areas where improvements can be made.
This article will review bacterial etiology, risk assessment, and issues surrounding antibiotic treatment and prevention of CAP.
Causative Agents
The most common bacterial agent causing CAP is S. pneumoniae, which is identified in up to 65% of cases.5 Other causative agents of CAP include:
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Classification of Patient Risk
Fine et al published the Pneumonia PORT Prediction rule that establishes reliable criteria for identifying patients at risk for morbidity and mortality from CAP. 6 This rule uses demographic factors, coexisting conditions, physical exam findings, and laboratory and radiologic findings to help stratify patients into those at risk for complications. The rule has been integrated into CAP practice guidelines from the Infectious Diseases Society of America (IDSA) and the American Thoracic Society (ATS).5,7 The Virtual Hospital website (http://www.vh.org/adult/provider/internalmedicine/CAP/CapTool/ToolStartPage.html) and PDA applications make this risk calculator available at the point of care. As a guideline this rule assists - but should not supersede - physician judgment.
The guideline stratifies patients into five different severity classes based on a two-step process.5
Step 1: Patients are placed into the lowest risk category (class I) if they are less than 50 years old, have none of the coexisting conditions listed in the Table 1, have normal or near normal vital signs and normal mental status. Those patients who do not fit the class I description are further classified in Step 2.
Step 2: Risk categories II through V are assigned based on the total points given for various demographic factors, coexisting conditions, physical exam findings, and laboratory and radiologic findings (Table 1). Patients assigned to class II generally do well with outpatient treatment. Patients assigned to risk class III may require brief inpatient therapy or outpatient therapy only, depending on physician judgment. Patients assigned to risk class IV or V should be hospitalized due to the potential for higher morbidity and mortality.
Availability of home care, risk of non-compliance, and other social factors are examples of situations not included in the risk assessment rule but should be considered when evaluating patient risk.
Treatment
Antibiotic Selection
Empiric treatment of outpatients consists of a macrolide, doxycycline
for children 8 and older, or a fluoroquinolone. Treatment of
patients who are hospitalized (moderately or critically ill) consists
of empiric therapy with either an extended-spectrum cephalosporin
plus a macrolide or monotherapy with a antipneumococcal
fluoroquinolone.5,7 The selection of antibiotic therapy is
based on studies that show a decrease in mortality with these
regimens as opposed to treatment with a cephalosporin
alone.8 Both regimens are equally recommended by the IDSA
and the ATS, although there have been recent reports of
fluoroquinolone resistance in locations associated with excessive
fluoroquinolone use. 5,9 Once the causative agent is
known, the recommendation is to change to an antimicrobial that is
the most specific to the infecting organism, least toxic, and most
cost-effective.
Prompt Administration of Antibiotics
Significant variation exists in the time to first antibiotic dose
at different institutions. One multicenter retrospective
cohort10 study investigated 14,000 Medicare patients (65
years of age or older) with a discharge diagnosis of pneumonia or
respiratory failure with a secondary diagnosis of pneumonia.
Antibiotic administration not given within 8 hours of hospital
arrival was associated with a significantly higher risk of mortality
at 30 days. Another retrospective chart review was conducted in 700
cases of patients hospitalized for pneumonia.4 Appropriate
antibiotic selection (according to IDSA guidelines), as well as a
shorter time interval between arrival to the hospital and
administration of antibiotic, resulted in a decreased length of stay.
Hence, observational evidence suggests that prompt administration
of antibiotics (within 8 hours of hospital arrival) results in
improved outcomes.
In response to these findings, JCAHO and Medicare quality measures recommend administration of antibiotics within eight hours of hospital arrival.11 Some care managers anticipate that the quality measure will change to antibiotic administration within four hours of hospital arrival (personal communication). One way to ensure patients get their first dose quickly is to initiate treatment in the Emergency Treatment Center (ETC), rather than after admission to the inpatient unit.
Antibiotic Administration in the Emergency Department
Appropriate antibiotic selection, coupled with administration in the
emergency treatment center, rather than waiting until a patient was
admitted to an inpatient floor, resulted in a shorter length of stay
(LOS) in a retrospective chart review of 100 cases of patients
hospitalized with pneumonia. 4
Another retrospective study evaluated more than 14,000 patients over the age of 65 in 3555 hospitals who were hospitalized with pneumonia.10 Four different aspects of CAP treatment were evaluated for their influence on 30-day mortality: 1) amount of time to receive antibiotics after arrival at the emergency department; 2) blood culture collection before initial hospital antibiotics; 3) blood culture collection within 24 hours of hospital arrival; and 4) oxygenation assessment within 24 hours of hospital arrival. Administering antibiotics within 8 hours of arrival (OR 0.85; 95%CI 0.76-0.95, no p value) and collecting blood cultures within 24 hours of hospital arrival were associated with decreases in 30-day mortality (OR 0.90; 95%CI 0.81-1.0, no p value).
The evidence suggests that rapid antibiotic delivery, facilitated by administration in the emergency department, reduces mortality and shortens LOS.
Critical Pathways for CAP Managment
Critical pathways (e.g., CareMaps, pre-printed orders, treatment algorithms) codify the steps of providing care and produce improved patient outcomes.13 Figure 1 provides a step-wise approach to the management of CAP.
The safety and effectiveness of utilizing a critical pathway for CAP management was evaluated by Marrie et al in a randomized controlled trial.14 Nine hospitals with 1743 patients were randomized to either a critical pathway or conventional treatment. A health-related quality of life form was utilized to measure the effectiveness of the pathway. The critical pathway consisted of three components: use of a clinical prediction rule, treatment with levofloxacin, and practice guidelines for the treatment of inpatients. The clinical prediction rule assigned a score to the patient at the emergency treatment center based on the Pneumonia PORT prediction rule (Table 1). The higher-risk patients (based on score) were then recommended for hospitalization. Treatment consisted of 500mg of oral levofloxacin for outpatients and 500mg IV levofloxacin for inpatients. IV therapy was administered within 4 hours of presentations to the emergency treatment center. The investigators then switched inpatients to oral therapy based on the following criteria: 1) able to eat and drink; 2) negative blood culture and criteria 3 to 5 for 16 hours beforehand; 3) temperature < 38ºC; 4) respiratory rate <24 /min; and 5) pulse rate < 100/min. Patients on oral therapy plus a white blood count < 12 x109, stable comorbid illness, O2 saturation > 90% on room air (and for patients with chronic obstructive pulmonary disease, pO2 > 60mmHg and pCO2<45mmHg) met criteria for hospital discharge. The patients were then treated with oral levofloxacin 500 mg daily for a total of 10 days. The investigators detected no differences in the occurrence of complications, readmissions, or mortality between the patients treated using the critical pathway and those receiving conventional therapy.
Early Switch from Intravenous (IV) to Oral Antibiotics
Most patients show a clinical response within 3 to 5 days of parenteral antibiotic therapy.5 Parenteral therapy is often the reason that hospital stays are extended. The rational for earlier switch to oral therapy is summarized by the following:
Evidence supporting early parenteral to oral antibiotic switch. A meta-analysis of nine prospective, interventional, CAP-specific studies with early switch criteria evaluated length of stay (LOS) for the switch criteria (discussed below), discharge criteria, and outcomes.12 The most common criteria used to switch patients from IV to oral were afebrile condition, improvement or resolution of respiratory signs and symptoms, and ability to take oral antibiotics
Criteria to consider when switching from IV to oral therapy:
The magnitude of impact on LOS was dependent on the pre-existing duration of hospitalization. Institutions where the LOS was initially longer than recommended by the guidelines exhibited the greatest decrease in LOS. If the institution already had a shorter LOS, it was unlikely to see any difference. Also, there was considerable regional variability in the treatment of CAP, which can be attributed to differences in patient, physician, and hospital-based factors.4 Regardless, the authors concluded that early switch and early discharge strategies will decrease LOS safely when the LOS is longer than recommended.
The evidence supports switching to oral antibiotics once the patient improves clinically.
Treatment Summary
Using the ETC to facilitate early antibiotic administration, implementation of critical pathways, and earlier conversion from parenteral to oral antibiotics are all examples of changes in process-of-care that can influence both the clinical and financial outcomes of CAP. Hospitals can modify and utilize these published studies as part of quality improvement efforts.
Figure 1: Flow diagram for laboratory work-ups and antibiotic delivery for patients hospitalized for CAP
Prevention
Most patients who are hospitalized with CAP are also candidates for the pneumococcal and influenza vaccines. Vaccinating patients at hospital discharge will decrease the likelihood of future morbidity and mortality from either disease. This is also a JCAHO performance measure, and an IDSA, ATS, and Centers for Disease Control and Prevention recommendation.5,15,16
How We Can Better Serve Patients at Univeristy of Iowa Hospitals and Clinics?
The following key points of CAP treatment reviewed above decrease mortality, LOS, and save UIHC and patients' resources:
References
Avoid Using These Dangerous Medical Abbreviations
Identifying ways to reduce medical errors continues to be a priority for healthcare organizations. One of the major causes of medication errors is the ongoing use of potentially dangerous abbreviations and dose designations. This problem has been extensively reviewed by several national safety organizations, including the Institute for Safe Medication Practices (ISMP), the National Coordinating Council for Medication Error Reporting and Prevention (NCCMERP), and the Joint Commission on the Accreditation of Healthcare Organizations (JCAHO). 1, 2, 3
Recently, JCAHO presented a list of Patient Safety Goals for 2003. Goal 2 on this list states:
To enhance the safety of communications, the JCAHO has recommended that healthcare organizations standardize any abbreviations, acronyms and symbols used throughout the organization and develop a list of abbreviations, acronyms and symbols that should not be used.4 Subsequently, the University of Iowa Hospitals and Clinics has identified several abbreviations that have been associated with unclear communications and could lead to medication errors. These medical abbreviations designated as dangerous and not approved for use are:
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DANGEROUS MEDICAL ABBREVIATIONS |
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Abbreviation |
Intended meaning |
Common Error |
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AAOC |
Antacid of choice |
Ambiguous. Requires other caregivers to determine what prescriber intended. May lead to the unintended administration of large amounts of magnesium, aluminum, or calcium. |
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LOC |
Laxative of choice |
Ambiguous. Requires other caregivers to determine what prescriber intended. May lead to the unintended administration of large amounts of sodium or magnesium. |
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T I W |
Three times a week |
Misinterpreted as "three times a day" or "twice a week." |
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U |
Unit / Units |
Mistaken as a zero or a four (4) resulting in overdose. Also mistaken for "cc" (cubic centimeters) when poorly written. |
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µg |
Micrograms |
Mistaken for "mg" (milligrams) when written, resulting in an overdose. |
Because of the safety concerns outlined above, the Pharmacy and Therapeutics Subcommittee and the Health Information Management Subcommittee have approved the deletion of these abbreviations from the UIHC's list of Approved Medical Abbreviations. Prescribers and other clinicians should write out complete words when ordering medication or other treatments designated in these ways. Prescribers will be notified to clarify orders using these dangerous abbreviations.