Monitoring abnormal laboratory values as antecedents to drug-induced injury

BACKGROUND

Clinical abnormalities associated with drug therapy may lead to injury if untreated. Detection of preceding drug-related hazardous conditions (DRHCs) may provide the opportunity to prevent injury. This study evaluated the frequency of abnormal laboratory values attributed to the effect of drugs.

METHODS

A total of 590 patients consecutively admitted to a surgical intensive care unit during a 3-month period were prospectively studied. Serum electrolyte, platelet, creatinine, glucose, magnesium, and liver enzyme concentrations were classified as either normal or abnormal using standard criteria. DRHCs were abnormal laboratory results determined to be caused by drugs.

RESULTS

DRHCs were detected in 16.4% of patients, reflecting a rate of 47 events per 1,000 patient days. 66%, 22%, and 12% of DRHCs were categorized as either definite, probable, or possible, respectively. In 97% of suspected DRHCs, clinicians responded by ordering additional laboratory tests or changing drug regimens.

CONCLUSIONS

Monitoring laboratory values and assessing the association to medications may reduce the risk of injury consequent to adverse drug events.

Intensive care unit quality improvement: A “how-to” guide for the interdisciplinary team*

OBJECTIVE

Quality improvement is an important activity for all members of the interdisciplinary critical care team. Although an increasing number of resources are available to guide clinicians, quality improvement activities can be overwhelming. Therefore, the Society of Critical Care Medicine charged this Outcomes Task Force with creating a "how-to" guide that focuses on critical care, summarizes key concepts, and outlines a practical approach to the development, implementation, evaluation, and maintenance of an interdisciplinary quality improvement program in the intensive care unit.

DATA SOURCES AND METHODS

The task force met in person twice and by conference call twice to write this document. We also conducted a literature search on "quality improvement" and "critical care or intensive care" and searched online for additional resources. DATA SYNTHESIS AND OVERVIEW: We present an overview of quality improvement in the intensive care unit setting and then describe the following steps for initiating or improving an interdisciplinary critical care quality improvement program: a) identify local motivation, support teamwork, and develop strong leadership; b) prioritize potential projects and choose the first target; c) operationalize the measures, build support for the project, and develop a business plan; d) perform an environmental scan to better understand the problem, potential barriers, opportunities, and resources for the project; e) create a data collection system that accurately measures baseline performance and future improvements; f) create a data reporting system that allows clinicians and others to understand the problem; g) introduce effective strategies to change clinician behavior. In addition, we identify four steps for evaluating and maintaining this program: a) determine whether the target is changing with periodic data collection; b) modify behavior change strategies to improve or sustain improvements; c) focus on interdisciplinary collaboration; and d) develop and sustain support from the hospital leadership. We also identify a number of online resources to complement this overview.

CONCLUSIONS

This Society of Critical Care Medicine Task Force report provides an overview for clinicians interested in developing or improving a quality improvement program using a step-wise approach. Success depends not only on committed interdisciplinary work that is incremental and continuous but also on strong leadership. Further research is needed to refine the methods and identify the most cost-effective means of improving the quality of health care received by critically ill patients and their families.

Are the Naranjo Criteria Reliable and Valid for Determination of Adverse Drug Reactions in the Intensive Care Unit?

BACKGROUND

The Naranjo criteria are frequently used for determination of causality for suspected adverse drug reactions (ADRs); however, the psychometric properties have not been studied in the critically ill.

OBJECTIVE

To evaluate the reliability and validity of the Naranjo criteria for ADR determination in the intensive care unit (ICU).

METHODS

All patients admitted to a surgical ICU during a 3-month period were enrolled. Four raters independently reviewed 142 suspected ADRs using the Naranjo criteria (review 1). Raters evaluated the 142 suspected ADRs 3–4 weeks later, again using the Naranjo criteria (review 2). Inter-rater reliability was tested using the kappa statistic. The weighted kappa statistic was calculated between reviews 1 and 2 for the intra-rater reliability of each rater. Cronbach alpha was computed to assess the inter-item consistency correlation. The Naranjo criteria were compared with expert opinion for criterion validity for each rater and reported as a Spearman rank (rs) coefficient.

RESULTS

The kappa statistic ranged from 0.14 to 0.33, reflecting poor inter-rater agreement. The weighted kappa within raters was 0.5402–0.9371. The Cronbach alpha ranged from 0.443 to 0.660, which is considered moderate to good. The rs coefficient range was 0.385–0.545; all rs coefficients were statistically significant (p < 0.05).

CONCLUSIONS

Inter-rater reliability is marginal; however, within-rater evaluation appears to be consistent. The inter-item correlation is expected to be higher since all questions pertain to ADRs. Overall, the Naranjo criteria need modification for use in the ICU to improve reliability, validity, and clinical usefulness.

Administration of enoxaparin by continuous infusion in a naturalistic setting: analysis of renal function and safety

STUDY OBJECTIVE

To describe the clinical use and safety of continuous infusion (CI) enoxaparin in a naturalistic setting and to evaluate the influence of renal function on enoxaparin elimination.

DESIGN

Retrospective medical record review.

SETTING

1000-bed tertiary care teaching centre.

PATIENTS

Hospitalized patients that received enoxaparin by CI during a 2-year period.

INTERVENTIONS

None.

MEASUREMENTS

Specific details of dosage and monitoring were collected. Adverse drug reactions (ADR) were recorded. Creatinine clearance (CrCl) was calculated using Cockroft and Gault and Brater equations. A population pharmacokinetic analysis was performed using the non-linear mixed effect model (NONMEM). For patients located in the intensive care unit (ICU) and ward, POSTHOC pharmacokinetic parameter estimates were evaluated using the Wilcoxon rank-sum. Pearson correlation coefficient was calculated to determine the association between renal function and anti-Xa clearance.

MAIN RESULTS

Sixty-seven patients received enoxaparin by CI of which 61.2% were in the ward and 38.8% in the ICU. The average initial rate and duration of infusion were 5.2 mg/h and 5.6 days, respectively. The number of anti-Xa concentration measurements averaged five per patient. Nine patients experienced an ADR. The most frequent ADR was gastrointestinal bleeding (n = 4). Among the 67 patients, 48 had available anti-Xa concentrations and were included in the NONMEM model. The anti-Xa CL and volume of distribution for ICU and ward patients averaged 0.64 +/- 0.34 L/h, 10.6 +/- 1.55 L and 1.01 +/- 0.39 L/h, 9.08 +/- 1.17 L, respectively. CrCl was not a significant covariate when included in the NONMEM model, and the association between CrCl and anti-Xa clearance was not significant (R2 = 0.0005; P = 0.8916).

CONCLUSIONS

This study is the first to report the use and safety of prolonged CI enoxaparin. Pharmacokinetic parameters of enoxaparin differ in ICU vs. ward patients. Overall, we found the safety of CI to be comparable to subcutaneous administration. Also, we found no effect of renal function on enoxaparin elimination.

Outcomes and costs of abciximab versus eptifibatide for percutaneous coronary intervention

BACKGROUND

Patients undergoing percutaneous coronary intervention (PCI) with stent placement are often prescribed glycoprotein IIb/IIIa inhibitors. However, drug selection is often based on clinicians' preference and cost because few studies have directly compared abciximab and eptifibatide.

OBJECTIVE

To compare clinical outcomes and total hospital costs of abciximab and eptifibatide in patients undergoing stent placement during PCI in a real-world setting.

METHODS

A retrospective cohort analysis was conducted of 960 patients administered abciximab or eptifibatide for intracoronary stent placement between 1999 and 2001 at a tertiary care hospital. The primary outcome was bleeding, defined as major, moderate, or minor according to published criteria. Secondary outcomes included in-hospital death, myocardial infarction, revascularization, and the triple composite endpoint of those outcomes, thrombocytopenia, length-of-stay, and total hospital costs. Pearson's chi(2) analysis, Fisher's exact test, and ANOVA were used for statistical analysis.

RESULTS

The frequency of bleeding complications based on severity was similar between abciximab and eptifibatide: major (2.4% vs 2.8%), moderate (12.4% vs 10.5%), and minor (4.0% vs 3.9%), respectively (p = 0.86). Secondary clinical outcomes were also similar between groups (p > 0.05). Total costs for hospitalization were significantly greater for abciximab compared with eptifibatide ($16,383 +/- 6799 vs $14,115 +/- 6285; p < 0.001). Drug acquisition costs were also significantly greater for abciximab compared with eptifibatide ($508 +/- 159 vs $465 +/- 263; p = 0.003).

CONCLUSIONS

In patients undergoing stent placement during PCI, abciximab and eptifibatide are comparable in terms of safety and effectiveness despite significant differences in hospitalization and acquisition costs.

Sedation Assessment in Critically Ill Adults: 2001–2004 Update

OBJECTIVE

To review recently published literature on the validity and reliability of sedation assessment tools in critically ill adults and evaluate the potential advantages and disadvantages of each.

DATA SOURCES

A computerized search of MEDLINE and PubMed (2001–May 2004) was conducted.

STUDY SELECTION AND DATA EXTRACTION

Sedation assessment tools used in adult intensive care units (ICUs) were identified.

DATA SYNTHESIS

Six subjective and 3 objective assessment tools were identified. Four subjective assessment tools have reliability and 4 have validity data published that were not previously available. There are reliability data to further support the use of the previously published Motor Activity Assessment Scale. Additional reliability data exist for the Ramsay Scale and Glasgow Coma Scale. Conflicting evidence is available with the use of the Bispectral Index monitor in the ICU. Recently, the Patient State Index and Auditory Evoked Potentials were introduced for objective monitoring in critically ill patients.

CONCLUSIONS

Increasing data on sedation assessment were published over the last few years, probably in response to supporting evidence that goal-driven sedation therapy improves patient outcomes. Reliability and/or validity testing exists for many of these scales. Several useful tools are available to guide sedation therapy in critically ill patients.

Intensive Insulin Therapy for Critically III Patients

OBJECTIVE:

To evaluate the clinical outcomes of glycemic control of intensive insulin therapy and recommend its place in the management of critically ill patients.

DATA SOURCES:

Searches of MEDLINE (1966—March 2004) and Cochrane Library, as well as an extensive manual review of abstracts were performed using the key search terms hyperglycemia, insulin, intensive care unit, critically ill, outcomes, and guidelines and algorithms.

STUDY SELECTION AND DATA EXTRACTION:

All articles identified from the data sources were evaluated and deemed relevant if they included and assessed clinical outcomes.

DATA SYNTHESIS:

Mortality among patients with prolonged critical illness exceeds 20%, and most deaths are attributable to sepsis and multisystem organ failure. Hyperglycemia is common in critically ill patients, even in those with no history of diabetes mellitus. Maintaining normoglycemia with insulin in critically ill patients has been shown to improve neurologic, cardiovascular, and infectious outcomes. Most importantly, morbidity and mortality are reduced with aggressive insulin therapy. This information can be implemented into protocols to maintain strict control of glucose.

CONCLUSIONS:

Use of insulin protocols in critically ill patients improves blood glucose control and reduces morbidity and mortality in critically ill populations. Glucose levels in critically ill patients should be controlled through implementation of insulin protocols with the goal to achieve normoglycemia, regardless of a history of diabetes. Frequent monitoring is imperative to avoid hypoglycemia.

Comparing Dexmedetomidine Prescribing Patterns and Safety in the Naturalistic Setting Versus Published Data

BACKGROUND:

In clinical practice, new drugs may be used differently than the product labeling recommends. Furthermore, it often takes several years of use before adverse drug reactions (ADRs) are reported.

OBJECTIVE:

To compare prescribing patterns and safety of the newly released drug dexmedetomidine as observed in clinical practice with published data on the drug.

METHODS:

Information from a convenience sample of adults receiving dexmedetomidine as part of routine patient care at 10 institutions was retrospectively collected from June 27, 2001, to May 31, 2002. Investigators reviewed medical records daily and entered dosing information, patient demographics, and predefined categories of ADR severity and probability anonymously via the Internet on a secure server.

RESULTS:

Only 33% of the total sample (n = 136) of patients received a loading infusion of dexmedetomidine; however, maintenance dosing was usually within product labeling guidelines. Of note, 27.2% of patients received dexmedetomidine above the maximum dose and 33.8% received the drug beyond 24 hours. Some patients (15.4%) were never mechanically ventilated, while 59.5% received dexmedetomidine following extubation for an average of 11.3 hours. ADRs were reported in 30% of patients: 20% of the reactions required treatment or increased length of stay. Hypotension was the most common ADR, occurring in 22.7% of patients. Bradycardia was reported in 4.4% of patients. The rate and type of ADRs were similar in patients receiving dexmedetomidine >24 hours compared with the total population.

CONCLUSIONS:

Dexmedetomidine is prescribed within product labeling guidelines except for low use of a loading dose, some patients received the drug at doses above the maximum, and others received it for longer than 24 hours. Since ADR rates are similar to those of other published reports, dexmedetomidine maintained its expected safety profile in our patients.