Alpers disease

Clinical Scenario

A 70-year-old woman has had worsening chronic obstructive pulmonary disease (COPD) for 20 years. She asks if she would benefit from long-term supplemental oxygen therapy. Her resting arterial blood gases show an oxygen ([O.sub.2]) saturation of 91 percent.

Clinical Question

Should patients with COPD and moderate hypoxemia (i.e., [O.sub.2] saturation of 90 to 97 percent) receive continuous home oxygen therapy?

Evidence-Based Answer

There is good evidence that the addition of home long-term continuous oxygen therapy for COPD increases survival rates in patients with severe hypoxemia (i.e., [O.sub.2] saturation of less than 90 percent or partial pressure of arterial oxygen [Pa[O.sub.2]] of less than 8 kPa per 60 mm Hg) but not in patients with moderate hypoxemia or nocturnal desaturation.

Practice Pointers

Continuous oxygen therapy is indicated in patients with COPD and severe hypoxemia. The Centers for Medicare and Medicaid Services (CMS), formerly known as the Health Care Financing Administration (HCFA), provides guidelines for supplemental oxygen therapy and sets the standard for nearly all adult oxygen prescriptions, whether the patient has Medicare or a managed care provider. (2) According to these standards, oxygen therapy is covered for patients with a documented Pa[O.sub.2] of up to 55 mm Hg or a saturation of oxygen in arterial blood (Sa[O.sub.2]) of up to 88 percent on room air at rest. Most insurers, including Medicare, will allow a prescription for home oxygen therapy for up to 99 months (or "lifetime," according to Medicare). CMS allows oxygen therapy for patients with an Sa[O.sub.2] of up to 89 percent if they have a coexisting clinical condition (i.e., cor pulmonale, congestive heart failure, hematocrit of more than 56 mg per dL).

The three modes of delivery for oxygen therapy include oxygen concentrators, compressed gas, and liquid oxygen. CMS uses a "modality neutral" method, which applies a fixed reimbursement regardless of the mode of delivery. Because survival rates are not better in patients with moderate hypoxemia, this review supports these coverage guidelines.

According to the results of this review, physicians should be vigilant in making sure that patients with COPD receive long-term oxygen therapy. One trial included in the review determined that continuous long-term oxygen therapy in patients with a Pa[O.sub.2] of up to 58 mm Hg reduced mortality rates over 24 months compared with nocturnal therapy (number needed to treat [NNT], 11). In another trial, patients with a Pa[O.sub.2] of 40 to 60 mm Hg who were treated with long-term oxygen therapy had increased five-year survival rates compared with patients who received placebo (NNT, five).

Other interventions that have proved effective in the treatment of patients with COPD also should be used, including long-acting [beta.sub.2] agonists, inhaled corticosteroids, pulmonary rehabilitation, and anticholinergic agents (e.g., ipratropium [Atrovent]), depending on the staging of disease. Transplant surgery may hold promise for some patients. These treatment recommendations can be found in the comprehensive guideline from the National Heart, Blood, and Lung Institute/World Health Organization Global Initiative for Chronic Obstructive Lung Disease Workshop and two recent systematic reviews. (3-6)

REFERENCES

(1.) Crockett AJ, Cranston JM, Moss JR, Alpers JH. Domiciliary oxygen for chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2000;4:CD001744.

(2.) Centers for Medicare and Medicaid Services. Coverage issues manual: durable medical equipment. Accessed June 4, 2004, at: http://www.cms.hhs.gov/manuals/06_cim/ci60.asp?#_1_3.

(3.) Fabbri LM, Hurd SS; GOLD Scientific Committee. Global strategy for the diagnosis, management and prevention of COPD: 2003 update. Eur Respir J 2003;22:1-2.

(4.) Pauwels RA, Buist AS, Calverley PM, Jenkins CR, Hurd SS; GOLD Scientific Committee. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. NHLBI/WHO Global Initiative for Chronic Obstructive Lung Disease (GOLD) Workshop summary. Am J Respir Crit Care Med 2001;163:1256-76.

(5.) Man SF, McAlister FA, Anthonisen NR, Sin DD. Contemporary management of chronic obstructive pulmonary disease: clinical applications. JAMA 2003;290:2313-6.

(6.) Sin DD, McAlister FA, Man SF, Anthonisen NR. Contemporary management of chronic obstructive pulmonary disease: scientific review. JAMA 2003;290:2301-12.

R. Eugene Bailey, M.D., is assistant professor of family medicine at State University of New York Upstate Medical University, Syracuse.

Address correspondence to R. Eugene Bailey, M.D., Center for Evidence-Based Practice, Department of Family Medicine, State University of New York Upstate Medical University, 475 Irving Ave., Suite 200, Syracuse, NY 13210 (e-mail: baileye@upstate.edu). Reprints are not available from the author.

This clinical content conforms to AAFP criteria for evidence-based continuing medical education (EB CME). EB CME is clinical content presented with practice recommendations supported by evidence that has been systematically reviewed by an AAFP-approved source. The practice recommendations in this activity are available online at http://www.cochrane.org/cochrane/revabstr/AB001744.htm.

The Cochrane Abstract below is a summary of a review from the Cochrane Library. It is accompanied by an interpretation that will help clinicians put evidence into practice. R. Eugene Bailey, M.D., presents a clinical scenario and question based on the Cochrane Abstract, along with the evidence-based answer and a full critique of the abstract.

These summaries have been derived from Cochrane reviews published in the Cochrane Database of Systematic Reviews in The Cochrane Library. Their content has, as far as possible, been checked with the authors of the original reviews, but the summaries should not be regarded as an official product of the Cochrane Collaboration; minor editing changes have been made to the text (www.cochrane.org).

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