Robert M. Elenbaas

Prophylactic oxacillin in dog bite wounds

This prospective, double-blind, placebo-controlled study was undertaken to determine the value of prophylactic oxacillin in dog bites. Adult patients with uninfected full-thickness wounds presenting within 24 hours of injury were considered. Management consisted of cleansing, irrigation, debridement, and closure as indicated; no topical antibiotics were applied. Patients were randomly assigned to receive oxacillin 500 mg QID x 5 days or identically appearing placebo. Home wound care was standardized an patients were observed at least every 2 days. Clinical assessment of infection was confirmed microbiologically. Sixty-three patients were admitted and 46 completed the study. Oxacillin (22) and placebo (24) groups were identical in sex, age, number of wounds per patient, wound location and type, number of open and closed wounds, delay to presentation, length of follow-up observation, medication compliance, and adequacy of patient wound care. Two infections of the hand occurred in patients receiving oxacillin; no infections were seen among placebo-treated patients (P = NS). Prophylactic oxacillin was not associated with improved outcome. We do not advise the use of prophylactic antibiotics in dog bite injuries treated within 24 hours of accident.

Failure of peak expiratory flow rate to predict hospital admission in acute asthma

Our study evaluated the ability of early peak expiratory flow rates (PEFR) to be predictive of hospital admission while double blinding the measurements and using a standardized treatment protocol and specific admission criteria. The measurements were recorded prior to and after initial therapy. Eighty-six acute asthmatic episodes in 51 patients were analyzed. Nine (10.5%) of the episodes resulted in hospitalization; 77 (89.5%) resulted in discharge. No correlation with admission was found for the initial PEFR, a second PEFR following treatment, or the differences between these two values. Our study indicates that early PEFRs alone are not useful predictors of the need for hospital admission. Although a significant number of patients in our study population presented with severe airflow obstruction, they responded sufficiently to treatment to permit discharge.

Evaluation of prophylactic oxacillin in cat bite wounds.

A prospective, double-blind, placebo-controlled study was undertaken to determine the influence of prophylactic oxacillin on the frequency of infection in cat bite wounds. Adult patients with uninfected full-thickness wounds presenting within 24 hours of injury were considered. Emergency department management consisted of cleansing, irrigation, debridement, and closure as indicated; no topical antibiotics were applied. Patients were randomly assigned to receive oxacillin 500 mg qid for five days or identically appearing placebo. Home wound care was standardized and patients were observed at least every two days for a minimum of five days, or until wounds were sufficiently healed to allow discharge from the study. Clinical assessment of infection was confirmed microbiologically when possible. Twelve patients were admitted and 11 completed the study. Oxacillin (n = 5) and placebo (n = 6) groups were identical in sex, age, number of wounds per patient, wound location and type, delay to emergency department presentation, length of follow-up observation, medication compliance, and adequacy of home wound care. Four of six patients receiving placebo, but none of the five receiving oxacillin, developed a wound infection (P = .045). Material obtained from three of these four patients yielded Pasteurella multocida as the responsible organism. Prophylactic oxacillin was thus associated with a significant reduction in the frequency of infection following cat bites. We recommend such therapy in the care of these wounds.

Use of peak expiratory flow rates to eliminate unnecessary arterial blood gases in acute asthma

Arterial blood gas (ABG) measurements are used frequently in acute asthma. Because ABGs are expensive and may have significant side effects, a method is needed to identify those patients at risk for a significantly abnormal ABG. We studied the use of peak expiratory flow rates (PEFR) to identify those patients at such risk. Data from 89 emergency visits by 51 asthmatic patients were analyzed. A small but significant correlation between ABG parameters and PEFR was observed (P less than 0.05). No patient with a PEFR greater than or equal to 25% predicted has a PaCO2 greater than 45 mm Hg or pH less than 7.35. This suggests that only those patients with a PEFR less than 25% predicted are at risk for significant hypercarbia or acidosis. We concluded that PEFR may be used as a simple screening tool to safely eliminate ABGs in at least 40% of acute asthmatic patients.

Evaluating the medical literature part I: Abstract, introduction, methods

In this installment on critical evaluation of medical literature, we have discussed the Abstract, Introduction, and Methods sections. A great deal of information is placed in the methodology section of any paper. To critically evaluate a research publication, one must evaluate the methodology, for evaluation of the results of an investigation is meaningless if the methodology is unsound.

DOSE EFFECTIVENESS AND SAFETY OF BUTORPHANOL IN ACUTE MIGRAINE HEADACHE

This study was undertaken to compare the effectiveness and safety of three dosage levels of butorphanol in 52 patients with acute, severe migraine headache. After baseline evaluation, patients were given a dose of butorphanol 1.0, 2.0, or 3.0 mg intramuscularly on a double‐blind basis. Assessments of pain intensity and pain relief using 100 mm linear analog scales (LAS), vital signs, and medication side effects were made at 15, 30, 45, and 60 minutes after the dose. All three treatment groups were similar in baseline characteristics. Each dose of butorphanol demonstrated a significant decrease in pain intensity LAS compared to baseline and increase in pain relief LAS over the observation period. The majority of analgesic response was observed at the first (i.e., 15‐min) assessment. Doses of 2.0 and 3.0 mg produced significantly greater analgesia than did 1.0 mg at all posttreatment evaluations. No significant difference was apparent between the 2.0‐ and 3.0‐mg doses. Adverse cardiovascular and respiratory depressant effects were not observed. An analgesic response to butorphanol 2.0 and 3.0 mg is clearly and rapidly evident and near maximum 30–45 minutes after administration. We conclude that in these doses butorphanol provides effective and safe analgesia for patients with acute migraine headache.

Prediction of serum theophylline levels

Because theophylline (T) has a narrow therapeutic index, serum concentrations resulting from previous outpatient therapy must be considered when planning intravenous (IV) aminophylline dosage in the emergency department (ED). Facilities to measure serum T concentrations rapidly are not available in all institutions. We therefore studied our ability to predict serum T concentrations in asthma or COPD patients, and assessed the probable outcomes if dosing decisions had been based on these predictions. Forty adult patients (mean age, 41.5 years) who had taken a theophylline preparation within 12 hours of ED presentation were studied. Serum T concentration was predicted based on each patients medication history and the use of standard pharmacokinetic equations, and was compared with the patients actual T level. The mean actual T concentration was 12.7 +/- 6.62 micrograms/mL, while the mean predicted T concentration was 11.4 +/- 5.37 micrograms/mL. If the predicted T concentrations had been used to plan subsequent IV aminophylline dosing, 68% of patients would have received therapy likely to place them within the range of 10 to 20 micrograms/mL; 15% would have received too little aminophylline, and 17% too much. Comparable results are noted if aminophylline dosing had been based simply on the elapsed time since the patients last oral T dose. While IV aminophylline dosing decisions can be made safely in many patients by considering their medication history or predicting serum T concentration, inappropriate and possibly dangerous therapy will result in a sizable, unpredictable minority. Aminophylline dosing in the ED ideally should be done with knowledge of the patients base-line theophylline level.

Evaluating the medical literature, Part III: Results and discussion

This series has addressed the basic segments of a research publication and discussed critical considerations that a reader should make as he progresses through the segments. The questions listed in Figure 3 may be helpful to guide the reader through the evaluation process.

Abscess formation as a complication of parenteral methylphenidate abuse

Case reports of five patients suffering from either skin abscesses or cellulitis following parenteral methylphenidate abuse are presented. Four patients had similar lesions consisting of abscesses or cellulitis which demonstrated typical signs and symptoms of an infective process and were treated with local symptomatic therapy, incision and drainage if indicated, and systemic antibiotics. The fifth patient suffered from a circular, necrotic, nonpurulent ulcer on the dorsum of the right foot which produced no local or systemic toxic effects. Attempts to culture a responsible organism yielded Streptococcus viridans, an organism which is normal flora of the skin and, although opportunistic, is generally considered nonpathogenic. These cases further substantiate the belief that local vasospasm, chemical irritation, or both, produced by the methylphenidate solution may primarily cause a necrotic ulcer susceptibble to secondary bacterial infection.

The effect of in-line filtration on tobramycin delivery.

The purpose of this study was to determine if the presence of an in-line 0.22 μ cellulose ester membrane filter would hamper the delivery of a common adult dose of tobramycin sulfate. Solutions of tobramycin sulfate 80 mg in 100 ml D5W were assayed after 30 minute infusions through unfiltered and filtered administration sets; solutions post-flush of filtered sets were also assayed. Assay was done by Emit-QST. The results indicated that there was no significant difference in the delivery of tobramycin sulfate, regardless of the presence of an in-line filter. Solutions post-flush contained about ten percent of the drug, reflecting the amount in solution that remained in the tubing. Since ten percent can alter pharmacokinetic monitoring for patient dosing, a consistent procedure for flushing filtered administration sets should be adopted to enhance accuracy of such determinations.