Editorials - February 1, 2001 American Family Physician

Editorials

Hope for Patients with Asplenia or Hyposplenism

ALAN TICE, M.D.
Infections Limited
Tacoma, Washington

In his article on the detection, education and management of asplenic and hyposplenic patients in this issue,¹ Brigden reviews important information on the role of the spleen and what can be done when this organ is absent or not functioning.

The first task is to identify patients who do not have a functional spleen. Because so many diseases can result in splenic hypofunction, a thorough medical and surgical history is important. A careful examination for abdominal scars may be valuable when a patient is unable to provide a good medical history. Although this is seldom reported, Howell-Jolly bodies are a useful laboratory clue to the diagnosis of hyposplenism or asplenia. Despite concerted efforts by physicians, patients who have undergone splenectomy often are not recognized and followed properly.^2,3

It is crucial to review the vaccination records of patients who do not have a functional spleen. Immunization against Haemophilus influenzae and meningococci strains seems reasonable, although a clear benefit has not been documented in adult asplenic patients. The major focus of management, however, should be immunization against Streptococcus pneumoniae, which is responsible for most cases of overwhelming postsplenectomy infection. In unvaccinated asplenic patients, the fatality rate for S. pneumoniae sepsis exceeds 40 percent.⁴

Pneumococcal vaccination is a timely issue because a more effective conjugated pneumococcal vaccine is now available for use in children. Furthermore, the need for revaccination of adults is receiving considerable attention. The increasing resistance of pneumococci to antibiotics, the waning immunity in the elderly population and the low incidence of adverse effects with the conjugated pneumococcal vaccine may make periodic boosters routine.

With the increase in antibiotic resistance and the introduction of more effective vaccines, antibiotic prophylaxis in asplenic patients and patients with sickle cell disease is being questioned. It appears that antibiotics can have a prompt and dramatic effect on pneumococcal resistance, as is demonstrated by the quick development of resistance in day care centers.⁵ It is also clear that the prolonged use of antimicrobial agents, or even the use of more potent antibiotics, leads to colonization, if not invasion, by resistant strains.

Overwhelming postsplenectomy infection remains a challenge in emergency medical management. Time is of the essence in treatment, and antibiotics are of questionable value once the cytokine cascade of sepsis and vasculitis has started. The search for immune modulators to interrupt this catastrophic chain of events has begun, although there are as yet no clearly effective inhibitors.⁶

At present, we rely on physicians to detect and treat patients without a functional spleen and to educate these patients about infection risks and necessary health precautions. So far, the results have not been good. As Brigden¹ points out in this issue, physicians must become more vigilant. He has even devised a checklist to encourage recognition of at-risk patients.²

Because patient education by physicians seems to be yielding only limited benefits, some investigators believe that additional systems should be in place to supplement the work of physicians.⁷ One option is a hospital look-back program for patients who have undergone splenectomy, with follow-up provided to ensure that these patients are vaccinated and know what to do if they develop an infection. Reviewing hospital discharge diagnoses might also be helpful. Other system changes, possibly incorporating administrative and organizational strategies, may be worthwhile, as has been demonstrated by vaccine programs.⁸

With proper data collection, electronic medical records hold the potential to electronically screen thousands, if not millions, of people for the diagnosis of splenic hypofunction. Software programs should be able to detect the vaccines a patient received and when. A history of splenectomy, related disease, or laboratory findings such as Howell-Jolly bodies could be useful indicators to match against vaccine status. It should then be possible to follow up on vaccination inadequacies and intervene with vaccines and patient education. We can hope to be able to apply this technology soon.

Alan Tice, M.D., is an infectious disease specialist and the founder of Infections Limited, Tacoma, Wash.

Address correspondence to Alan Tice, M.D., Infections Limited, 401 Broadway, Tacoma, WA 98402.

REFERENCES

Brigden ML. Detection, education and management of the asplenic or hyposplenic patient. Am Fam Physician 2001;63:499-506,508.

Brigden ML, Patullo A, Brown G. Pneumococcal vaccine administration associated with splenectomy: the need for improved education, documentation, and the use of a practical checklist. Am J Hematol 2000;65:25-9.

Kind EA, Craft C, Fowles JB, McCoy CE. Pneumococcal vaccine administration associated with splenectomy: missed opportunities. Am J Infect Control 1998;26:418-22.

Waghorn DJ, Mayon-White RT. A study of 42 episodes of overwhelming post-splenectomy infection: is current guidance for asplenic individuals being followed? J Infect 1997;35:289-94.

Pichichero ME. Acute otitis media: part II. Treatment in an era of increasing antibiotic resistance. Am Fam Physician 2000;61:2410-6.

Kox WJ, Volk T, Kox SN, Volk HD. Immunomodulatory therapies in sepsis. Intensive Care Med 2000;26(suppl 1):S124-8.

Sarangi J, Coleby M, Tivella M, Reilly S. Prevention of post-splenectomy sepsis: a population-based approach. J Public Health Med 1997;19:208-12.

Nichol KL. Ten-year durability and success of an organized program to increase influenza and pneumococcal vaccination rates among high-risk adults. Am J Med 1998;105:385-92.

The Science and Politics of Cancer Screening

LARRY L. DICKEY, M.D., M.P.H.
University of California
San Francisco, California

The article in this issue, "Screening for Cancer: Evaluating the Evidence,"¹ clearly reviews the basic science behind screening tests. Most readers will find this article useful, although it contains little new data. We should have learned this information in medical school or other professional training, although it is likely that we have forgotten much of it. How many of us have ordered tests with no specific diagnosis in mind and without considering the potential disadvantages to the patient? How many of us have struggled to explain to patients (and ourselves) why a particular screening test is or is not worthwhile?

The scientific principles of screening are essentially counterintuitive. It is always better to "know" than to be in the dark, right? Detecting disease at an early stage is always better than finding it at a later stage, right? If only it were so simple. We and our patients are bombarded by all types of media messages based on such common-sense, but incorrect, assumptions. Talk-show hosts expound on the benefits of mammography for normal-risk 35-year-old women, and the U.S. Postal Service issues stamps extolling "annual check-ups and tests" for prostate cancer.

Perhaps the most telling fact about the state of disease screening in the United States can be found in another recently published article. Rathore and colleagues² surveyed government codes in every state that mandates insurance coverage of screening tests for cancer. In the 43 states with such codes, as well as Washington, D.C., not one code was based on the recommendations of the U.S. Preventive Services Task Force (USPSTF).³ This is surprising, given that the USPSTF recommendations are widely accepted as the most thoroughly researched and evidence-based recommendations of any group. Apparently science and the evidence regarding screening tests are not necessarily the driving force for legislators and other opinion leaders in our society today.

Some genuine public health success stories have been achieved with screening tests, such as the large reduction in cervical cancer mortality attributable to the use of Papanicolaou smears. However, it is sobering to consider the large number of patients that must be screened for 10 years to prevent just one death (1,140 patients in the case of Pap smears, according to Gates¹). Screening is not a panacea and, in some cases, our efforts might be better invested in primary prevention efforts, such as promoting tobacco avoidance and good nutrition.

Unfortunately, screening tests have entered the highly charged arena of gender politics. In this arena they have become valued commodities, often despite scientific evidence of effectiveness or ineffectiveness. It was not an accident that the prostate cancer stamp was issued in the year following the highly popular breast cancer stamp. The quest for gender equity does not necessarily make for good screening-test policy. As Gates¹ clearly explains in his article, more screening is not necessarily better screening--and, in some cases, it may be worse.

It is the role of physicians not only to understand the scientific underpinnings of screening and to use them in practice but also to explain those principles to patients and the wider community. The information contained in Gates' article¹ will provide a good starting point for this explanation but may not be sufficient. How do we explain the obscure concepts of lead time and length bias to our patients? How much do patients care about false-positive or false-negative results?

Schwartz and colleagues⁴ recently found that women express high tolerance for false-positive mammography results; 63 percent thought that 500 or more false-positive results per life saved would be an acceptable rate, and 37 percent thought that even 10,000 false-positive results per life saved would be acceptable. More such studies are needed to help us learn how to approach discussions of these epidemiologic concepts with our patients.

Finally, which scientific arguments, if any, are most influential with policy makers? Some authorities, such as former Assistant Secretary for Health, Phillip R. Lee, M.D.,⁵ have called for better use of cost-effectiveness and cost-benefit analysis to influence policy makers--issues that in the past have not been well addressed by the USPSTF. Trading in the dry concepts of epidemiology for the dollars-and-cents arguments of cost analysis may provide more potent antidotes to the experiential and emotional appeals of many advocacy and political groups. As physicians, we need to be advocates not only for our patients but for science as well. Hundreds of years of medical progress have shown that the interests of the two are essentially one and the same.

Larry Dickey, M.D., M.P.H., is assistant adjunct professor of family and community medicine at the University of California, San Francisco, Calif.

Address correspondence to Larry Dickey, M.D., M.P.H., Department of Family and Community Medicine, Box 0900, University of California, San Francisco, CA 94143.

REFERENCES

Gates TJ. Screening for cancer: evaluating the evidence. Am Fam Physician 2001;63:513-22.

Rathore SS, McGreevey JD 3d, Schulman KA, Atkins D. Mandated coverage for cancer-screening services: whose guidelines do states follow? Am J Prev Med 2000;19:71-8.

U.S. Preventive Services Task Force. Guide to Clinical Preventive Services: report of the U.S. Preventive Services Task Force. 2d ed. Baltimore: Williams & Wilkins, 1996.

Schwartz LM, Woloshin S, Sox HC, Fischhoff B, Welch HG. US women's attitudes to false positive mammography results and detection of ductal carcinoma in situ: cross sectional survey. BMJ 2000;320:1635-40.

Soller M, Lee PR. A new look at preventive care guidelines. Am J Prev Med 1999;17(4):315-6.

Copyright © 2001 by the American Academy of Family Physicians.
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