in the study (71 men, ages 63 + 19 years). Overall, peak flows increased (102 + 50 L/min before treatment, 139 + 84 L/min after treatment, P < .001); respiratory rates decreased (34 + 7 before, 29 + 7 after, P < .001); and heart rates did not change (115 + 20 before, 114 + 20 after, P = .51). In 62% of patients, the increase in flow exceeded 15%. Wheezing improved in 59% of the patients, wors- ened in 4%, and did not change in the others. Air entry improved in 59% of patients. Mild tremor occurred in 8% of patients, moderate tremor occurred in 1%, and no tremor occurred in the others. Significant dysrhythmias did not occur. Advanced life support providers correctly identified patients for this therapy, and no technical problems were encountered in the field with this treatment approach. We conclude that advanced life support pro- viders can be taught to identify patients likely to benefit from inhaled metaproterenol, that inhaled metaproterenol can be ad- ministered in the field, and that metaproterenol is both Safe and effective when used in the prehospital setting.

108 Comparison of Two Delivery Methods of Albuterol in Emergency Department Management of Acute Asthma FR LaFleche, DP Milzman, CB Philput, MJ Bone, J Vargas/Eastern Virginia Graduate School of Medicine, Emergency Medicine Residency Program, Eastern Virginia Medical School, Norfolk

In acute ashtma, t~ sympathomimetics have long been admini- stered by hand-held nebulizers in emergency departments. Newer studies have demonstrated the ease and efficacy of using metered- dose inhalers with spacer attachments in the ambulatory care treat- ment of chronic obstructive pulmonary disease and asthma. This single-blind, prospective study compared the efficacy of albuterol administered by hand-held nebulizer versus a metered-dose-in- haler with an InspirEase ® attachment. Forty-nine adult patients with acute asthma presenting to the ED were randomly assigned to one of two groups. Treatment consisted of either 2.5 mg albuterol in 3 mL normal saline by hand-held nebulizer (group 1 ) or six puffs of albuterof (0.6 mg) given at one-minute intervals by metered-dose inhaler with the InspirEase ® attachment (group 2) repeated every 30 minutes three times. The groups were well matched for age, sex, prior medication, and severity of attack as determined by a physi- cian severity assessment score and initial peak expiratory flow rate (PEFR). There was no statistical difference in PEFR improvement between the two groups. Group 1 (25) had pretreatment PEFRs of 166.5 + 63.2 and post-treatment PEFRs of 280.5 + 89.6 versus 159.6 + 56.5 and 285.0 + 88.0 for group 2 (24). There was also no difference in the frequency of administration of aminophylline, steroids, admission, or adverse side effects. We conclude that albuterol administered with a metered-dose inhaler with the InspirEase ® attachment is as effective as hand-held nebulizers for the treatment of acute asthma in the ED and offers the advantage of lower cost and ease of administration.

109 Utility of Peak Expiratory Flow Rate in the Differentiation of Acute Dyspnea: Pulmonary Edema Versus Obstructive/Bronchospastic Disease RM McNamara, D Cionni/Medical College of Pennsylvania, Philadelphia

It occasionally may be difficult in the prehospital or emergency department setting to distinguish the etiology of an acute episode of respiratory distress. This study prospectively examined the~use- fulness of the absolute peak expiratory flow rate (PEFR} in the dif- ferentiation of acute, moderate-to-severe dyspnea due to conges- tive heart failure (CHF) with pulmonary edema from that secon- dary to obstructive/bronchospastic lung disease (OBLD}. Adult ED patients, age 30 or older, were included if a PEFR was determined prior to pharmacologic intervention and a data sheet was com- pleted regarding their ED evaluations. Only episodes of dyspnea thought due to CHF or OBLD alone at the t ime of hospital discharge

,were subjected to analysis. Statistical analysis used Fisher's exact test or an unpaired t test when appropriate. A total of 36 episodes (OBLD, 22; CHF, 14) of acute, moderate-to-severe dyspnea in 35 patients met the entry criteria. There was no statistically signifi- cant difference between the two groups in age, sex, race, and the presenting respiratory rate, heart rate, mean arterial blood pressure, or the presence of diaphoresis. The majority of the OBLD group ( 19 of 22, 86%) presented with wheezing; however, a large percentage of the CHF group (ten of 14, 71%) also presented with some degree of wheezing. The OBLD group was more likely to report taking bronchodilators (91% vs 36%, P < .001) and less likely on a loop diuretic and/or digoxin ( 14 % vs 57 %, P < .01 ). The mean absolute

PEFR + SD for the OBLD group was 110 + 49 L/min versus 225 + 97 L/min for the CHF group (P < .0001}. By combining the medication history with the PEFR it was possible to correctly classify all episodes. PEFR appears to be a useful tool in differentiating acute dyspnea secondary to these entities.

110 Innovations in Aminophylline Monitoring and Therapy RJ Kino, R Day, G Pearce, G Fulde/Australasian College of Emergency Medicine, St Vincent's Hospital, Sydney, Australia

We hypothesized that an individualized computer-based proto- col can improve accuracy in achieving targeted therapeutic plasma theophylline levels and limit toxicity, as compared with standard clinical practice. We prospectively compared theophylline concen- trations achieved in two sequential groups of emergency depart- ment patients requiring IV aminophylline for acute bronchospasm. Control patients (46) received aminophylline therapy according to widely used clinical guidelines, while the amount of aminophyl- line given to experimental group patients (43) was individualized according to a computerized model. The computer used easily defined patient characteristics and included baseline theophylline levels measured rapidly by residents in the ED with a monoclonal antibody test kit.

Percent of Patients Achieving Therapeutic, Subtherapeutic, and Toxic Plasma Theophylline Concentrations at One and Six Hours

One hour Sixhours Control(%) Experimental(%) Control(%) Experimental(%)

Toxic (> 20 ~tg/mL) 7 0 10 0 Therapeutic ( 10 to 20 #g/mL) 26 81 37 91 Subtherapeutic ( < 10 ~tg/mL ) 67 19 53 9

We conclude that a computerized dosage prediction protocol that incorporated baseline plasma theophylline concentrations resulted in dramatic improvement in the ability to achieve therapeutic plasma theophylline concentrations in ED patients.

111 Impact of Portable Pulse Oximetry on Arterial Blood Gas Analysis in an Urban Emergency Department S Joseph, AL Kellermann, CA Cofer, BB Hackman/Divisions of Emergency Medicine and Cardiology, University of Tennessee, Memphis

Arterial blood gas (ABG) analysis is one of the ten most costly emergency department tests based on cost t imes frequency or- dered. Portable pulse oximetry offers a simple, noninvasive way to assess oxygen saturation, but its impact on physician ABG testing and quality of care is unknown. For two months preceding and two months following introduction of a protable pulse oximeter in our teaching ED, resident physicians recorded, for all ABGs, their reason for ordering the test, primary patient problem, and planned management in response to ABG results. Following introduction of oximetry, residents were also required to obtain an oximetry reading and attach it to each ABG request that did not involve a cardiac or respiratory arrest. The only educational intervention offered was a brief (five-minute) orientation to the use and limita- tions of pulse oximetry. Case records were subsequently reviewed by one board-certified physician blinded to visit date to determine the percentage of ABGs ordered during both periods that were indicated by explicit clinical criteria. A total of 20,120 patient visits were noted during the four-month study period. During the two months prior to introduction of oximetry, ED resident physicians ordered 695 ABGs, 436 (63 %) of which were indicated by American College of Emergency Physicians or American College of Physi- cians criteria. During the two months following introduction of oximetry, ABG use decreased by 43% (95% C1 = 34% to 52%, P < .001). This difference was not explained by differences in total patient visits or case mix. Residents decreased their ordering of indicated ABGs l~y almost as great a degree as they reduced ordering of unindicated tests, suggesting they did not reliably distinguish between the two. However, decreased ABG test ordering was not associated with any serious adverse patient outcomes. Based on projected totals, we estimate that this device (which retails for $2,450) will decrease laboratory charges in our ED by $95,000 per year. We conclude that portablepulse oximetry offers a highly cost effective way to decrease ABG test use without compromising quality of care.

112 Aspiration During Manual Low-Frequency Jet Ventilation

178/458 Annals of Emergency Medicine 18:4 April 1989