A 29 y/o female with NIDDM and poorly controlled chronic asthma present s with 3days of sob and wheezing typical of her prior asthma exacerbations.  After two nebulizer treatments and dose of corticosteroids her PEFR is measured at 55% of predicted.  Should she be admitted?

PEFR is not going to make this decision for you.

PEFR monitoring has not been shown to reliably predict need for admissions among patients who, or relapse from outpatient treatment.

Using specific PEFR cut offs for admission have led to increased admission rates without improving outcome measures.

Severely diminished PEFR (e.g. <100ml/min) post treatment have been shown to require inpatient treatment, but these are not patients in which the admission decision is otherwise in question.

ACEP recommends PEFR to assess treatment progress in particular patients per clinician judgment in the ED setting, but not as a requirement for evaluating all asthma patients or as admission criteria. 

References:

American College of Emergency Physicians. Use of Peak Expiratory Flow Rate Monitoring for the Management of Asthma in Adults in the Emergency Department. Ann Emerg Med. 2001;38:198

Abisheganaden J, Ng SB, Lam KN, et al. Peak expiratory flow rate guided protocol did not improve outcome in emergency room asthma. Singapore Med J. 1998;39:479-484.

Banner AS, Shah RS, Addington WW, et al. Rapid prediction of need for hospitalization in acute asthma. JAMA 1976;235:1337-8.

Corre KA, Rothstein RJ. Assessing severity of adult asthma and need for hospitalization. Ann Emerg Med 1985;14:45-52.

Emerman CL, Woodruff PG, Cydulka RK, et al. Prospective multicenter study of relapse following treatment for acute asthma among adults presenting to the emergency department. MARC investigators. Multicenter Asthma Research Collaboration. Chest.1999;115:919-927.

Nowak RM, Pensler MI, Sarkar DD, et al. Comparison of peak expiratory flow and FEV1 admission criteria for acute bronchial asthma. Ann Emerg Med..1982;11:64-69.