Association Between Sedative Medication Administration and Delirium Development in a Medical Intensive Care Unit

Background: Delirium develops frequently in intensive care unit (ICU) patients. Societal guidelines have suggested that benzodiazepines may cause delirium. This study investigates if a change in sedation administration use over time is associated with changes in delirium incidence. Methods: This was a retrospective cohort study conducted over a 4 year time period in a medical ICU. All data was abstracted from a local data warehouse. The primary outcome of the study was the association between annual cumulative benzodiazepine use and incidence of delirium during the study period. Data was analyzed using descriptive characteristics and Spearman's correlation coefficient. Additionally, multivariate logistic regression was performed to identify independent risk factors for delirium development. Results: From 2015 to 2018, annual total benzodiazepine administration decreased from 62,215 mg to 18,105 mg lorazepam equivalents (p = <.01). The cumulative dose of dexmedetomidine increased, with 657,262 mcg administered in 2015 and 1,476,951 mcg in 2018 (p < .01). No differences in annual delirium incidence were found. Risk factors that were significantly correlated with delirium following multivariate logistic regression included acute respiratory distress syndrome, renal failure, hepatic failure, septic shock, severe alcohol withdrawal, vasopressor use, corticosteroid use, benzodiazepine use, antipsychotic use, opiate use, and propofol use. Conclusions: A profound change in sedation medication paradigm did not influence delirium rates in a medical ICU.

Reconsidering Dexmedetomidine for Sedation in the Critically Ill: Implications of the SPICE III Trial

Dexmedetomidine is a sedative agent that has gained popularity for use in the intensive care unit over the past 20 years. Guidelines recommend dexmedetomidine as a first-line agent to achieve light sedation in mechanically ventilated adults. Recently, the SPICE III (Sedation Practice in Intensive Care Evaluation III) trial was published. This was a randomized controlled trial comparing initial sedation with dexmedetomidine with usual care sedation in adult patients receiving mechanical ventilation. The results of this trial have both validated and contradicted previous findings about dexmedetomidine. This editorial examines the merits of the SPICE III trial and the role of dexmedetomidine in practice following its publication.

Incidence of Rebound Hypertension after Discontinuation of Dexmedetomidine

INTRODUCTION

To date, no studies have evaluated the incidence of rebound hypertension occurring with the discontinuation of long-term (> 72 hrs) dexmedetomidine infusions. Rebound hypertension has been documented in the literature with clonidine, a structurally and pharmacologically similar medication.

OBJECTIVES

To compare the incidence of rebound hypertension associated with cessation of dexmedetomidine infusion with other sedative medications.

METHODS

This retrospective, matched cohort study evaluated the incidence of rebound hypertension in intensive care unit patients receiving continuous infusions of at least 72 hours in duration of dexmedetomidine, propofol, or midazolam.

RESULTS

The study population consisted of 216 patients: 54 treated with dexmedetomidine and 162 treated with propofol or midazolam. Rebound hypertension occurred significantly more often in patients with a history of hypertension (71.1%) than in patients with no prior hypertension (28.9%; p<0.001).There was no difference in incidence of rebound hypertension in the dexmedetomidine or propofol and midazolam arms (16.7% vs 17.9%, p=0.837). The titration timeframe for the dexmedetomidine infusion, defined as the time from peak infusion rate until discontinuation, was significantly shorter in patients with rebound hypertension (median duration, 4 hrs) compared with patients who did not have rebound hypertension (median duration, 17 hrs; p=0.011).

CONCLUSION

There was no difference in the incidence of rebound hypertension observed with dexmedetomidine discontinuation compared with propofol or midazolam. Instead, history of hypertension and a shorter weaning duration appear to be associated with increased risk of rebound hypertension regardless of the sedative used.

Evaluation of Intravenous Phenytoin and Fosphenytoin Loading Doses: Influence of Obesity and Sex

BACKGROUND

Recommended loading doses (LDs) of phenytoin and fosphenytoin range from 10 to 25 mg/kg. Few studies have examined the LD requirements in male versus female patients and in patients who are obese.

OBJECTIVES

To examine the influence of obesity and sex on phenytoin LDs.

METHODS

This was a retrospective cohort study comparing free phenytoin or fosphenytoin serum concentrations following LDs in male versus female and nonobese versus obese patients. An equation used for determining LDs in obese patients was evaluated.

RESULTS

There were 141 nonobese and 54 obese patients. When adjusted for total body weight, the obese cohort received a smaller LD than the nonobese cohort (17 mg/kg, interquartile range [IQR] = 14.9-20.0, vs 20 mg/kg, IQR = 18.6-20.0, respectively; P < 0.001). There was no difference between the 2 cohorts in the measured free phenytoin concentration following the LD (obese: 1.7 µg/mL [IQR = 1.4-2.0]; nonobese: 1.8 µg/mL [IQR = 1.5-2.1]; P = 0.16). In the obese cohort, men received a significantly lower weight-based phenytoin dose compared with women (15 mg/kg [IQR = 14.0-19.2], vs 19.9 mg/kg [IQR = 15.0-20.0], respectively; P = 0.008). Postload free phenytoin concentrations were similar between the 2 groups (male: 1.6 µg/mL [IQR = 1.2-2.1]; female: 1.7 µg/mL [IQR = 1.4-2.0]; P = 0.24). Conclusion and Relevance: Phenytoin and fosphenytoin LDs of at least 15 mg/kg of actual body weight are more likely to lead to desired free phenytoin concentrations. Obese female patients need a larger weight-based dose than male patients to achieve similar postload phenytoin concentrations.

1071. Impact of Standard vs. Prolonged Courses of Antibiotics for the Treatment of Uncomplicated Staphylococcus aureus Bacteremia (SAB) in Patients With Hematologic Malignancies

Background

The optimal treatment duration for uncomplicated SAB (U-SAB) is unknown in patients with hematologic malignancies. The goal of this study was to evaluate the impact of antibiotic duration on outcomes in patients with hematologic malignancies and U-SAB.

Methods

This was a multicenter, retrospective cohort study of adult patients with hematologic malignancies and U-SAB treated with standard (2 weeks) or prolonged (>2 weeks) antibiotic therapy. U-SAB was defined as defervescence and culture clearance within 96 hours of index culture and the absence of: endocarditis, implanted prostheses, metastatic sites of infection, and bone/joint involvement. Patients with SAB therapy <10 days and those with inadequate source control were excluded. The primary outcome was a composite global clinical cure: absence of relapse SAB, absence of SAB progression, and survival at 60 days following index SAB.

Results

Of 89 included patients, 51% received a standard antibiotic duration for U-SAB. The median age of the entire cohort was 56 and majority was male (60%). Neutropenia was present at index culture in 53% of patients, and acute leukemia (48%) and lymphoma (26%) were the most common underlying malignancies. Other baseline characteristics were similar between the two groups except more patients in the standard duration group had relapsed/refractory malignancy (51% vs. 25%, P = 0.016), central-line source (71% vs. 48%, P = 0.032), and antibiotic prophylaxis prior to index SAB (42% vs. 18%, P = 0.021). Median duration of treatment in the standard group was 15 days vs. 28 days in the prolonged duration group. No differences in global clinical cure and other clinical outcomes were seen between groups (Figure 1). On multivariable logistic regression analysis, only relapsed/refractory malignancy was identified as an independent predictor of global clinical failure (odds ratio, OR, 9.43; 95% confidence interval, CI, 1.17–76.9; P = 0.035). Duration of treatment was not associated with global clinical cure (OR, 2.92; 95% CI, 0.51–16.7; P = 0.23).

Conclusion

No differences in clinical outcomes were seen in patients with active hematologic malignancies who received 2 weeks vs. >2 weeks of antibiotic therapy for the treatment of U-SAB, although confirmation of our findings in a larger study is warranted.

Disclosures

All authors: No reported disclosures.

Angiotensin II Brings More Questions Than Answers

The approval of synthetic human angiotensin II (Giapreza, LaJolla Pharmaceuticals) by the FDA in December 2017 provides clinicians with a new tool in the treatment of distributive shock. Angiotensin II (ATII) was approved based on the results of the ATHOS-3 trial. In this trial, patients who received angiotensin II were more likely to achieve a mean arterial pressure of 75 mmHg or an increase in mean arterial pressure of 10 mmHg above that seen in patients who received a placebo. However, the results of ATHOS-3 also highlighted important concerns about thrombotic and infectious complications associated with ATII. Given that the cost of medication acquisition is approximately $1,500 per vial, practitioners must also decide how to implement ATII into practice in the most cost-effective manner. This commentary examines the current controversies surrounding both the safety and efficacy of ATII.

Evaluation of Vancomycin Dosing in Patients With Cirrhosis: Beginning De-Liver-ations about a New Nomogram

Background: Reduced hepatic production of creatinine precursors in patients with decompensated cirrhosis leads to falsely low serum creatinine values. Therefore, when performing empiric dosing of vancomycin, an overestimation of creatinine clearance may result in significantly supratherapeutic vancomycin levels and increased risks of nephrotoxicity. Objective: The objective of the study is to evaluate vancomycin dosing requirements in patients with cirrhosis stratified by Child-Pugh Score, with subsequent comparison with doses that are recommended in the previously published and validated Kullar nomogram. Methods: A retrospective evaluation of patients with cirrhosis who received vancomycin for at least 3 full days and had at least 1 serum concentration drawn. Vancomycin daily dose and corresponding serum concentration were collected with patients stratified by Child-Pugh Score for comparison. Each patient had their vancomycin dose compared with the dose suggested by a published nomogram. Results: A total of 201 courses of vancomycin were followed. There were no significant differences between the Child-Pugh cohorts with respect to initial vancomycin dosing. There was also no significant difference in the median initial vancomycin trough concentration between the 3 cohorts (Child-Pugh A: 13.7 µg/mL [interquartile range, IQR: 10.4-22.1]; Child-Pugh B: 20.2 µg/mL [IQR: 15.1-25.9]; Child-Pugh C: 19.3 µg/mL [IQR: 14.9-25.2, P = .08]. The median vancomycin dose using the Kullar nomogram would have been 3.0 g/day (IQR: 2.0-3.75, P < .001), but the median dose actually used in this patient population was significantly less at 2.0 g/day. Nonetheless, the median vancomycin trough concentration in the entire patient population was 19.8 µg/mL (IQR: 15.4-25.9). Conclusion: In patients with cirrhosis, there was a high incidence of supratherapeutic vancomycin serum concentrations despite the fact that dosing was significantly less than that suggested by the published Kullar nomogram.

Knowledge of appropriate acetaminophen use: A survey of college-age women

OBJECTIVES

To evaluate college-age women's knowledge of appropriate doses and potential toxicities of acetaminophen, competency in interpreting Drug Facts label dosing information, and ability to recognize products containing acetaminophen.

METHODS

In this cross-sectional prospective study, a 20-item written survey was provided to female college students at a University of Michigan fundraising event in March 2015.

RESULTS

A total of 203 female college students, 18-24 years of age, participated in the study. Pain was experienced on a daily or weekly basis by 22% of the subjects over the previous 6 months, and 83% reported taking acetaminophen. The maximum 3-gram daily dose of extra-strength acetaminophen was correctly identified by 64 participants; an additional 51 subjects indicated the generally accepted 4 grams daily as the maximum dose. When provided with the Tylenol Drug Facts label, 68.5% correctly identified the maximum amount of regular-strength acetaminophen recommended for a healthy adult. Hepatotoxicity was associated with high acetaminophen doses by 63.6% of participants, significantly more than those who selected distracter responses (P < 0.001). Knowledge of liver damage as a potential toxicity was correlated with age 20 years and older (P < 0.001) but was independent from race and ethnicity and level of alcohol consumption. Although more than one-half of the subjects (58.6%) recognized that Tylenol contained acetaminophen, fewer than one-fourth correctly identified other acetaminophen-containing products.

CONCLUSION

Despite ongoing educational campaigns, a large proportion of the college-age women who participated in our study did not know and could not interpret the maximum recommended daily dose from Drug Facts labeling, did not know that liver damage was a potential toxicity of acetaminophen, and could not recognize acetaminophen-containing products. These data suggest a continued role for pharmacists in educational efforts targeted to college-age women.

Recurrent Clostridium difficile infection in intensive care unit patients

BACKGROUND

The purpose of this study was to assess the 12-week cumulative incidence of recurrent Clostridium difficile infection (rCDI) and identify risk factors for rCDI in patients that acquired index C difficile infection (CDI) while in the intensive care unit (ICU).

METHODS

This retrospective single-center cohort study reviewed adult patients from 6 different ICUs who developed a CDI between February 2010 and September 2013.

RESULTS

Out of 162 included ICU patients, 34 experienced rCDI. Risk of rCDI was higher in the ICU versus non-ICU group (21% vs 17%, P = .03). The incidence of rCDI was highest in the surgical intensive care unit (SICU) at 43.8%. A multivariable logistic regression model was constructed and identified 5 significant risk factors for rCDI: previous CDI (odds ratio [OR], 8.03; 95% confidence interval [CI], 1.90-34.02; P = .005), log10 ICU length of stay in days (OR, 3.67; 95% CI, 1.13-11.85; P = .03), acquisition of CDI in the medical intensive care unit (MICU) (OR, 5.35; 95% CI, 1.60-17.85; P = .006) or SICU (OR, 15.30; 95% CI, 4.09-57.23; P < .001), and chronic obstructive pulmonary disease (COPD) (OR, 3.55; 95% CI, 1.41-8.94; P = .007).

CONCLUSION

ICU adults had a significantly higher 12-week incidence of rCDI than non-ICU patients. Risk factors for rCDI after acquisition of infection in an ICU include MICU and SICU patients, previous CDI, COPD, and length of stay.

Vasopressor and Inotropic Management Of Patients With Septic Shock

Numerous studies have evaluated the role of vasopressors and inotropes in the management of septic shock. This review assesses available evidence for the use of specific vasopressors in the management of septic shock. Use of adjunctive vasopressor therapy is also evaluated, examining the potential value of individual agents. Lastly, inotropic agents are evaluated for use in patients with myocardial dysfunction.

Role of Unit-Specific Combination Antibiograms for Improving the Selection of Appropriate Empiric Therapy for Gram-Negative Pneumonia

In an effort to improve the selection of appropriate empiric gram-negative therapy for pneumonia, we examined intensive care unit-specific combination antibiograms. These antibiograms were able to predict appropriate empiric gram-negative therapy. Empiric combination therapy based on unit-specific combination antibiograms may aid in the selection of therapy for gram-negative pneumonia.

Retrospective analysis of azithromycin versus fluoroquinolones for the treatment of legionella pneumonia

BACKGROUND

Legionella is often associated with life-threatening pneumonia that is responsible for significant morbidity and mortality. Fluoroquinolones (FQ) have demonstrated improved clinical outcomes or decreased complications compared with clarithromycin and erythromycin. However, there is limited data comparing outcomes of FQ to azithromycin (AZM), which exhibits better Legionella activity than erythromycin and clarithromycin.

METHODS

This single-center retrospective study compared clinical outcomes of patients with Legionella pneumonia (LP) treated with AZM versus FQ from January 1999 to May 2011.

RESULTS

A total of 41 patients were included in the analysis; 21 received FQ and 20 received AZM. Demographics, comorbidities, and disease severity were similar between groups. Mortality (9.5% vs. 5%, P > 0.99), time to clinical stability (15.89 days vs. 10.26 days, P = 0.09), length of hospitalization (19.29 days vs. 11.35 days, P = 0.06), and presentation of any complication (85.7% vs. 90%, P > 0.99) were similar between the FQ and AZM groups, respectively.

CONCLUSION

Azithromycin appears to have clinical efficacy similar to FQ for the treatment of Legionella pneumonia.

Apparent argatroban resistance in a patient with elevated factor VIII levels

OBJECTIVE

To report a case in which there was a lack of activated partial thromboplastin time (aPTT) correlation with plasma argatroban concentrations in a patient with elevated factor VIII levels who was diagnosed with heparin-induced thrombocytopenia (HIT).

CASE SUMMARY

A 59-year-old female with a history significant for basal cell carcinoma was transferred from an outside hospital and underwent resection of a third ventricle mass. The postoperative hospital course was complicated by subdural hematoma, HIT, and pulmonary embolism. Upon initiation of argatroban, we faced difficulty in maintaining therapeutic aPTT values despite administration of significantly higher than usual doses of argatroban (up to 7 μg/kg/min). A coagulation abnormality was suspected and an argatroban concentration was obtained; results showed an elevated level of 2.2 μg/mL (therapeutic range 0.4-1.2), with a corresponding aPTT of 53.1 seconds. A coagulopathy workup revealed an excess of factor VIII activity. Thereafter, argatroban concentrations were used for dose adjustments and the infusion was titrated to a final rate of 2.75 μg/kg/min.

DISCUSSION

The lack of correlation of aPPT values with argatroban administration has not been described in the literature and, to our knowledge, similar cases have not been reported. We were unable to achieve an increase in aPTT, despite aggressive argatroban dosing in a patient with increased factor VIII activity. A definitive mechanism for this is not entirely known; however, it is thought to be secondary to contributing underlying causes such as excessive clotting factors, circulating inflammatory proteins, or other aspects.

CONCLUSIONS

With the initiation of argatroban therapy, particular attention should be given to ensure that aPTTs correlate with dosing to prevent life-threatening bleeding complications. Excessive argatroban dosing requirements should prompt further investigation into potential confounders such as elevated factor VIII levels.

Combination Therapy for the Treatment and Prevention of Hepatic Encephalopathy

OBJECTIVE:

To evaluate the efficacy and safety of combination therapy for the treatment and prevention of hepatic encephalopathy (HE).

DATA SOURCES:

A PubMed MEDLINE search was conducted (1947-June 2012) using the key terms lactulose, lactitol, nonabsorbable disaccharide, metronidazole, rifaximin, neomycin, probiotics, and hepatic encephalopathy. Searches were limited to include articles published in English.

STUDY SELECTION AND DATA EXTRACTION:

Study selection included published trials, case reports, and case series of humans with HE who were treated with combination therapy of rifaximin, lactulose, lactitol, metronidazole, neomycin, and/or probiotics.

DATA SYNTHESIS:

Only 6 studies that evaluated the benefits of combination drug therapy in the treatment or prevention of HE were available for review. Four studies addressed the treatment of HE, 2 found no significant difference between lactulose/neomycin versus placebo or rifaximin/lactulose, 1 assessed the use of rifaximin/lactulose without a control group, and the fourth found no significant difference between lactulose/probiotics versus either drug alone, although each group showed improvement from baseline. In the 2 prevention trials, both of which stemmed from the same data, the combination of rifaximin/lactulose was superior to lactulose alone, showing significant improvement in mental status, blood ammonia levels, and health-related quality of life and reductions in HE recurrence and hospitalization. Currently, there are no available clinical studies evaluating dual antibiotic therapy, metronidazole with nonabsorbable disaccharides, or antibiotics with probiotics.

CONCLUSIONS:

The evidence evaluating the use of combination therapy for the treatment of HE does not support its widespread use. The combination of rifaximin and lactulose may be considered in the treatment of HE and in patients refractory to monotherapy. The combination of rifaximin and lactulose should be considered for the prevention of HE, especially after the second episode of HE recurrence.

Vancomycin versus linezolid in the treatment of methicillin-resistant Staphylococcus aureus nosocomial pneumonia: implications of the ZEPHyR trial

In 2003, a retrospective trial comparing linezolid versus vancomycin in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) showed improved survival in the linezolid group. This led to the ZEPHyR (Linezolid in the Treatment of Subjects with Nosocomial Pneumonia Proven to Be Due to Methicillin-Resistant Staphylococcus aureus) trial comparing linezolid versus vancomycin for MRSA pneumonia, which showed a benefit for linezolid with respect to clinical response but without a survival advantage. Limitations of the study included unbalanced treatment groups at baseline and number of patients excluded to reach the per-protocol group. Results of the ZEPHyR trial do not support routine use of linezolid for the treatment of MRSA pneumonia.

Cost analysis before and after implementation of a computerized physician order entry order form for enoxaparin

OBJECTIVE

The authors sought to analyze the impact of a computerized physician order entry (CPOE) order form for enoxaparin sodium injection (Lovenox) to reduce the daily cost of drug therapy by switching appropriate patients to once-daily enoxaparin administration.

METHODS

The study population included patients older than 18 years of age who had been treated with enoxaparin from September 1 to December 31, 2008 (the pre-order form implementation group) and from March 1 to June 30, 2009 (the post-order form implementation group). The wholesale acquisition cost was used to determine the cost of enoxaparin per day. Appropriate dosing was established by chart review.

RESULTS

The post-implementation group showed a trend toward a higher cost of enoxaparin therapy per day compared with the pre-implementation group (P = 0.23). There was a non-significant increase in appropriate dosing after implementation of the order form-from 64.5% before implementation to 71.5% after implementation (P = 0.13). In the overall cohort, although the authors controlled for other factors that could influence cost, patients who received the appropriate dose per protocol were 3.2 times more likely (95% confidence interval, 1.8-5.9; P = 0.001) to have lower enoxaparin drug costs per day of therapy.

CONCLUSION

The use of a CPOE enoxaparin order form did not reduce the daily cost of therapy.

Knowledge of appropriate acetaminophen doses and potential toxicities in an adult clinic population

OBJECTIVE

To evaluate the knowledge of appropriate doses and potential toxicities of acetaminophen and assess the ability to recognize products containing acetaminophen in an adult outpatient setting.

DESIGN

Cross-sectional, prospective study.

SETTING

University adult general internal medicine (AGIM) clinic.

PATIENTS

104 adult patients presenting to the clinic over consecutive weekdays in December 2003.

INTERVENTIONS

Three-page, written questionnaire.

MAIN OUTCOME MEASURES

Ability of patients to identify maximum daily doses and potential toxicities of acetaminophen and recognize products that contain acetaminophen.

RESULTS

A large percentage of participants (68.3%) reported pain on a daily or weekly basis, and 78.9% reported use of acetaminophen in the past 6 months. Only 2 patients correctly identified the maximum daily dose of regular acetaminophen, and just 3 correctly identified the maximum dose of extra-strength acetaminophen. Furthermore, 28 patients were unsure of the maximum dose of either product. Approximately 63% of participants either had not received or were unsure whether information on the possible danger of high doses of acetaminophen had been previously provided to them. When asked to identify potential problems associated with high doses of acetaminophen, 43.3% of patients noted the liver would be affected. The majority of the patients (71.2%) recognized Tylenol as containing acetaminophen, but fewer than 15% correctly identified Vicodin, Darvocet, Tylox, Percocet, and Lorcet as containing acetaminophen.

CONCLUSION

Although nearly 80% of this AGIM population reported recent acetaminophen use, their knowledge of the maximum daily acetaminophen doses and potential toxicities associated with higher doses was poor and appeared to be independent of education level, age, and race. This indicates a need for educational efforts to all patients receiving acetaminophen-containing products, especially since the ability to recognize multi-ingredient products containing acetaminophen was likewise poor.

Compliance with Institutional Guidelines on the Use of Vancomycin in a Medical Intensive Care Unit

Purpose

The University of Michigan implemented guidelines and restrictions for the use of vancomycin in 1995, based on recommendations from the Centers for Disease Control and Prevention. This study evaluated vancomycin use in the University of Michigan's Medical Intensive Care Unit (MICU), and assessed compliance with these institutional guidelines.

Methods

The primary objective of the study was to assess compliance with institutional guidelines. All patients admitted to the MICU who received vancomycin during the period of October 2002 through January 2003 were included in the study. Patients were identified retrospectively and patient medical records were accessed to gather pertinent information. Approval of the Institutional Review Board was obtained.

Results

Fifty-one patients received a total of 71 courses of vancomycin therapy (55 empiric, 16 definitive). Fifty-five (77.5%) of the 71 total courses of vancomycin therapy met institutional criteria. All courses of definitive therapy met specific criteria. Thirty-nine (71%) of the 55 courses of empiric therapy met criteria. Of the courses of empiric therapy which did not fulfill criteria, 12 were from patients exhibiting signs of sepsis and received vancomycin for more than 72 hours, and nine involved immunocompromised patients.

Conclusions

The implementation of guidelines and restrictions is essential to limiting and preventing resistance, but are only effective if designed with the specific hospital's patient population in mind. The results of this study suggest that immunocompromised patients may require a different approach than what is allowed by existing criteria.

Relationship Between Hyperglycemia and Infection in Critically Ill Patients

Hyperglycemia is a common problem encountered in hospitalized patients, especially in critically ill patients and those with diabetes mellitus. Uncontrolled hyperglycemia may be associated with complications such as fluid and electrolyte disturbances and increased infection risk. Studies have demonstrated impairment of host defenses, including decreased polymorphonuclear leukocyte mobilization, chemotaxis, and phagocytic activity related to hyperglycemia. Until 2001, hyperglycemia (blood glucose concentrations up to 220 mg/dl) had been tolerated in critically ill patients not only because high blood glucose concentrations were believed to be a normal physiologic reaction in stressed patients and excess glucose is necessary to support the energy needs of glucose-dependent organs, but also because the true significance of short-term hyperglycemia was not known. Recent clinical data show that the use of intensive insulin therapy to maintain tight blood glucose concentrations between 80 and 110 mg/dl decreases morbidity and mortality in critically ill surgical patients. Intensive insulin therapy minimizes derangements in normal host defense mechanisms and modulates release of inflammatory mediators. The principal benefit of intensive insulin therapy is a decrease in infection-related complications and mortality. Further research will define which patient populations will benefit most from intensive insulin therapy and firmly establish the blood glucose concentration at which benefits will be realized.

Impact of a critical pathway on inpatient management of diabetic ketoacidosis

To assess the management of diabetic ketoacidosis (DKA) and evaluate if introduction of a critical pathway improves management, we studied adults admitted with DKA to the Medicine and Critical Care Services in a US teaching hospital. Patients admitted with DKA in 1997 before implementation of the critical pathway were the control group (n=72). In 1998, housestaff and nurses in the emergency department (ED) and on the General Medicine and Critical Care Services were instructed in the use of the critical pathway. Patients admitted with DKA during 1998 (n=77) were the intervention group. Length of stay (LOS), hospital cost, adherence to guidelines, and medical outcomes to be avoided were compared, and regression analyses were performed to correlate processes and outcomes of care. Mean LOS and variability in LOS decreased during the intervention period, especially in patients treated without endocrinology consultation (EC) (5.2 +/- 10.6 vs. 2.4 +/- 2.1 days, P=0.01), and hospital cost and variability in cost tended to decrease ($6441 +/- 15,204 vs. $3625 +/- 3478, P=0.24). More intervention subjects received the recommended intravenous fluid volume (88 vs. 71%, P=0.013), education in sick-day management (77 vs. 54%, P=0.006), and EC (38 vs. 21%, P=0.03). Insulin management was not changed. We conclude that implementation of a DKA critical pathway reduced practice variation and was associated with shorter LOS and a trend toward decreased cost. Some processes of care were improved but many require additional interventions.

Conformational change in bacterio-opsin on binding to retinal

The detailed mechanism of retinal binding to bacterio-opsin is important to understanding retinal pigment formation as well as to the process of membrane protein folding. We have measured the temperature dependence of bacteriorhodopsin formation from bacterio-opsin and all-trans retinal. An Arrhenius plot of the apparent second-order rate constants gives an activation energy of 11.6 +/- 0.7 kcal/mol and an activation entropy of -4 +/- 2 cal/mol deg. Comparison of the activation entropy to model compound reactions suggests that chromophore formation in bacteriorhodopsin involves a substantial protein conformational change. Cleavage of the polypeptide chain between residues 71 and 72 has little effect on the activation energy or entropy, indicating that the connecting loop between helices B and C is not involved in this conformational change.

Thrombosis resulting from heparin therapy

Heparin is widely used in current practice for a variety of indications. It is well known that it can cause thrombocytopenia, but not that thrombosis may also develop in thrombocytopenic patients and cause significant morbidity and mortality. A 56-year-old woman developed heparin-induced thrombocytopenia with thrombosis that resulted in the amputation of her leg. It is proposed that the reaction has an immune-mediated mechanism. Several ways of diagnosing the condition are available, specifically the serotonin-release assay and an enzyme-linked immunosorbent assay. The investigational agent danaproid may be effective in the treatment of heparin-induced thrombocytopenia with thrombosis.

Pharmacologic management of adult idiopathic nephrotic syndrome

The pathophysiology, clinical features, complications, and pharmacologic management of adult idiopathic nephrotic syndrome are reviewed. Loss of plasma proteins in the urine is the primary process leading to the nephrotic syndrome, which is characterized by hypoalbuminemia, hyperlipidemia, and edema. The four principal causes, or subclasses, of adult idiopathic nephrotic syndrome are membranous nephropathy (MN), minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), and membranoproliferative glomerulonephritis (MPGN); definitive diagnosis requires histologic examination of a renal biopsy specimen. Treatment of nephrotic syndrome may be directed at the specific cause of the proteinuria, the proteinuria itself, or the complications induced by the syndrome. The four subclasses of nephrotic syndrome vary in their response to therapy. Corticosteroids, alone or in combination with cytotoxic agents, and cyclosporine have been used to induce partial or complete remission in patients with MN, MCD, and FSGS; combinations of corticosteroids, cytotoxic agents, platelet inhibitors, and anticoagulants have been used to treat patients with MPGN. Treatment of proteinuria involves dietary protein restriction with the possible addition of an angiotensin-converting-enzyme inhibitor or a nonsteroidal anti-inflammatory drug. Management of the complications of nephrotic syndrome encompasses the use of diuretics; a low-cholesterol, low-fat diet; lipid-lowering agents; and anticoagulants. Patients with nephrotic syndrome are in a constant state of flux with respect to fluid status, organ function, and critical protein balance. Treatment is based on the histologic subclass of the disease.

The use of norfloxacin in a university hospital

Because of increasing norfloxacin use and the development of resistant organisms, an evaluation was undertaken in a University Hospital to assess the appropriateness of norfloxacin for the treatment of urinary tract infections and to calculate the potential cost savings associated with more cost-effective antibiotic therapy. Medical records of 64 patients receiving norfloxacin for a 31-day period were concurrently reviewed. Of these, 58 patients were treated for urinary tract infections and four patients received urinary tract infection prophylaxis. Fourteen patients were prescribed solely empiric therapy whereas an additional 44 patients received definitive treatment confirmed by culture results. Based on the predetermined criteria, norfloxacin use for the definitive treatment of urinary tract infections was deemed to be appropriate in 34 of the 44 patients. Three additional courses of therapy were also judged to be appropriate due to documented signs and symptoms associated with urinary tract infections, despite cultures with less than 10(5) colony forming units per mL urine. Reasons for inappropriate use in the remaining seven patients included isolation of fewer bacteria than required by the criteria in asymptomatic patients (3 cases), isolation of organisms not sensitive to norfloxacin (1 case) and lack of dosage adjustment for renal insufficiency (3 cases). Nineteen of 32 evaluable inpatients (59%) received norfloxacin when a less expensive, equally effective agent was available. Although savings from more cost-effective therapy of urinary tract infections are minimal, due to the potential emergence of resistant organisms, norfloxacin should be reserved for infections not amenable to treatment with other oral antibiotics.

Appropriate but not cost effective ceftazidime use in a university hospital

An evaluation of ceftazidime use at a university hospital was performed. Drug utilization evaluations usually categorize therapies as appropriate or inappropriate, with the inappropriate category including all regimens which are not cost effective. This may be misleading since therapy which is therapeutically appropriate may be labeled as inappropriate. Therefore, ceftazidime use was classified as appropriate, appropriate but not cost effective, or inappropriate. Clinical pharmacists reviewed the charts of 72 patients over a 1 month period. Courses of therapy were first categorized as empiric or definitive and as appropriate or inappropriate. Those that were appropriate were further analyzed to determine cost effectiveness. When a more cost effective regimen was available, the difference in cost was calculated; the cost of inappropriate therapy was compared to that of an appropriate alternative regimen. Ceftazidime use was appropriate and cost effective in 22% of courses, appropriate but not cost effective in 66%, and inappropriate in 11%. Annual savings of up to $72,000 could be realized in our 550 bed hospital by intervention into appropriate but not cost effective therapy and inappropriate therapy.

Management of cirrhotic ascites

The pathogenesis and diagnosis of cirrhotic ascites are reviewed, and the treatment options are described, focusing on pharmacologic management. The major theories on the pathogenesis of cirrhotic ascites are the underfill and overflow theories. The underfill theory states that ascites formation results in decreased plasma volume leading to renal sodium and water retention. The overflow theory states that the initial event in ascites formation is renal sodium retention. Evidence suggests that the formation of ascites is a continuum involving both overflow (early) and underfill (late) mechanisms. Although the most frequent cause of ascites is hepatic cirrhosis, analysis of the ascitic fluid is important to exclude other causes (e.g., neoplasm, peritonitis, pancreatitis). Patients who do not respond to treatment with sodium restriction and bed rest require diuretic therapy. Spironolactone is the agent of choice for treatment of the nonazotemic patient with cirrhotic ascites. Combination therapy with spironolactone and furosemide or spironolactone and metolazone may be used in those patients who do not respond to spironolactone. Patients with impaired renal function should not be treated with spironolactone because of the risk of hyperkalemia. Paracentesis with albumin replacement has been used successfully for treatment of patients with tense cirrhotic ascites. Initial management of cirrhotic ascites is conservative, with sodium restriction and bed rest. Spironolactone is a good first-choice drug for treatment of ascites. Daily weight, serum electrolytes, and renal function should be monitored to assess the effectiveness and potential adverse effects of diuretic therapy.