ANNUAL REHAB FOR CHRONIC AIRWAY OBSTRUCTION

Should patients with chronic airway obstruction (CAO) undergo pulmonary rehabilitation each year? New evidence suggests that annual rehabilitation does reduce the rate of exacerbations and provides short-term improvement in dyspnea, exercise tolerance, and health-related quality of life. However, it does not lower the annual number of CAO hospitalizations, and the short-term improvements do not result in long-term gains.

Foglio et al observed 61 CAO patients who underwent an eight-week outpatient pulmonary rehabilitation program (PRP1). These patients were randomized into two groups, the first of which (group 1) completed a second rehabilitation program (PRP2) one year later, whereas group 2 received no such therapy. At the end of the second year, both groups were reevaluated before beginning a third rehabilitation program.

Groups 1 and 2 were similar in baseline characteristics, and both their lung function test results and clinical course were similar in the year after PRP1. Immediately after PRP2, exercise tolerance, dyspnea, and health-related quality of life improved further in group 1; group 2 experienced no such improvement. By the end of the second year, though, the only difference between the two groups was that the rate of exacerbations was lower in group 1.

In both groups, the rate of hospitalizations was lower in the two years after PRP1 than it had been in the two years before the first rehabilitation program. And at the two-year follow-up, both groups continued to rate their health-related quality of life as higher than it had been before PRP1.

Foglio K, Bianchi L, Ambrosino N. Is it really useful to repeat outpatient pulmonary rehabilitation programs in patients with chronic airway obstruction? A two-year controlled study. Chest. 2001;119:1696-1704.

ASTHMA’S CONNECTION WITH IRRITABLE BOWEL SYNDROME

Irritable bowel syndrome (IBS) patients may have an increased prevalence of asthma, according to some research. This observation led investigators from Turkey to evaluate respiratory function in 133 IBS patients and 137 controls.

The two groups of patients were well matched; roughly 80% of both groups were women, and the average age in each group was about 40 years. Both groups completed subjective reports of respiratory symptoms, as well as pulmonary function tests.

Excluded from the study were persons older than 50 years, those with acute respiratory tract infection or gastrointestinal disease, current or former smokers, and those using medication that affects the autonomic nervous system.

Results showed that 33.8% of the IBS patients had respiratory symptoms, compared with 5.8% of the controls. Furthermore, 15.8% of the IBS patients, but only 1.5% of the controls, had physician-confirmed asthma. There were also statistically significant differences between the two groups in forced expiratory volume in one second, maximal mid-expiratory flow, peak expiratory flow rate, and flow after 50% of vital capacity had been exhaled.

The authors believe that their findings support the hypothesis that asthma and IBS may share common pathophysiologic mechanisms.

Yazar A, Atis S, Konca K, et al. Respiratory symptoms and pulmonary functional changes in patients with irritable bowel syndrome. Am J Gastroenterol. 2001;96:1511-1516.

FEVER A POOR INDICATOR OF FLU ONSET IN ELDERLY

Symptoms of influenza in the elderly may not include fever, according to research presented at the American Geriatrics Society 2001 Annual Scientific Meeting. Furthermore, the flu symptoms that do appear may do so gradually, unlike the way they manifest in younger patients.

In two studies, Vij et al examined the symptoms exhibited by 125 elderly patients; of these, 30 had culture-confirmed influenza A, 66 had influenza B, and 29 had respiratory syncytial virus (RSV). The authors noted that only 26%, 38%, and 31% of these patients, respectively, had had a temperature above 37.2°C (99°F) when symptoms first appeared.

A more prevalent indicator of flu infection on the day of symptom onset was cough, which appeared in 76% of the patients with influenza A, 55% of those with influenza B, and 52% of those with RSV. Within 48 hours of symptom onset, auscultative findings were present in 83%, 33%, and 69% of patients, respectively.

The investigators concluded that the lack of fever was likely attributable to elderly patients’ reduced capacity for thermoregulation. This would make fever a less reliable sign of underlying problems. They also said that attention to cough and chest sounds would be more important during the early stages of suspected flu. Such attention would presumably increase the likelihood that treatment could be provided in the most critical 48-hour period after flu onset.

Vij S, Gravenstein S, McElhaney J, et al. Influenza B presentation in elderly patients. Presented at: American Geriatric Society 2001 Annual Scientific Meeting; May 11, 2001; Chicago.

Vij S, Gravenstein S, McElhaney J, et al. Presentation of RSV and influenza in the elderly population. Presented at: American Geriatric Society 2001 Annual Scientific Meeting; May 11, 2001; Chicago.

DOES SMOKING CESSATION CAUSE RECURRENT DEPRESSION?

Smokers with a history of major depression who stop smoking are at high risk for recurrent depression, and this risk persists for at least six months after they quit. Antidepressant administration does not increase the likelihood that such patients can stop smoking, but it may lower their risk of recurrent depression.

Glassman et al enrolled 100 people who smoked one or more packs of cigarettes per day into a two-month smoking cessation trial. All participants had a history of major depression, but none had received an antidepressant medication for at least six months before the study’s start. Participants were randomized to receive the antidepressant sertraline or placebo, and were told to stop smoking 21 days after the start of treatment. They were then evaluated three and six months after treatment ended.

Of the 76 participants who returned for follow-up, 42 were able to quit; 34 continued to smoke. Depression recurred in 13 of the abstainers and two of the smokers. The risk of recurrence was not time-dependent: Among the abstainers, seven episodes of recurrent depression occurred in the first three months of follow-up and six in the second three months.

The quit rate in the patients given sertraline was no different from that in patients given placebo. However, recurrent depression was twice as common in the placebo group.

The authors concluded that patients with a history of major depression are at high risk of recurrence when they quit smoking. But it is not yet clear, they said, whether antidepressant administration or nicotine replacement is a reasonable prophylactic strategy.

Glassman AH, Covey LS, Stetner F, Rivelli S. Smoking cessation and the course of major depression: a follow-up study. Lancet. 2001;357:1929-1932.

CAN OXYGEN PREVENT CNS EVENTS IN SICKLE CELL PATIENTS?

Could nocturnal oxygen supplementation be an alternative to blood transfusion for preventing cerebral complications in patients with sickle cell disease? The underlying physiologic rationale for this hypothesis is that nocturnal breathing disorders can induce hypoxemia, which, in turn, promotes polymerization of sickle hemoglobin, as well as the adhesion of red cells and platelets to vascular endothelium.

To investigate this issue, Kirkham et al studied 95 patients with sickle cell disease with overnight oximetry and transcranial Doppler sonography. The patients, none of whom had previously experienced a stroke, ranged in age from 1 to 23 years.

During a median follow-up of six years, 19 patients suffered a central nervous system (CNS) event: seven had strokes, eight had transient ischemic attacks, and four had seizures.

Three variables—low mean overnight oxygen saturation (SaO2), high internal carotid or middle cerebral artery blood velocity, and high hemoglobin concentration—were independently associated with time to onset of a CNS event. In patients with an SaO2 of 96% or higher, there was little risk of a CNS event. In contrast, in patients with an SaO2 below 96%, the hazard ratio was 5.6.

Kirkham et al speculate that nocturnal oxygen supplementation could be less expensive and safer than blood transfusion for the prevention of CNS events in patients with sickle cell disease. A controlled trial is being conducted to evaluate the efficacy of this approach.

Kirkham FJ, Hewes DKM, Prengler M, et al. Nocturnal hypoxaemia and central-nervous-system events in sickle-cell disease. Lancet. 2001;357:1656-1659.

GENDER DIFFERENCES IN ASTHMA SYMPTOMS

Among patients who present to the emergency department (ED) with asthma, women are more likely than men to report severe symptoms and activity limitations. However, the level of airway obstruction is similar in the two sexes, according to a study by Cydulka et al.

Investigators from 64 EDs in 21 states and four Canadian provinces provided data on 1,291 patients with moderate to severe asthma exacerbations (defined as a peak expiratory flow rate [PEFR] below 80% of predicted); 62% were women. While mean PEFR was slightly lower in the men (41% vs 47% of predicted), women were significantly more likely to be admitted to the hospital for treatment (24% vs 14%). Women were also more likely to complain of “severe” activity limitations, though frequently the exacerbation was only moderate as measured by PEFR.

The study authors suggest using objective measurements of airway obstruction, such as PEFR, because symptom presentation does not appear to accurately reflect disease severity.

Reduced awareness of obstruction due to long-standing airflow difficulties, structural differences in the lungs, and social issues may all contribute to gender differences in asthma presentation.

Cydulka RK, Emerman CL, Rowe BH, et al. Differences between men and women in reporting of symptoms during an asthma exacerbation. Ann Emerg Med. 2001;38:123-128.

ANTIBIOTIC ROTATION HELPS PREVENT RESISTANCE

Quarterly rotation of empirical antibiotics may be an effective way to combat morbidity and mortality from antibiotic-resistant infections in intensive care units (ICU), suggest Raymond et al.

Their prospective cohort study evaluated antibiotic rotation as a method for reducing the emergence of resistant organisms and thereby improving survival in 540 cases of infection identified during a two-year period in the University of Virginia Health Sciences Center’s ICU. During the first year of the study, empiric antibiotics were administered according to the physicians’ prescriptions; during the second year, a quarterly rotating empiric antibiotic schedule was used.

The patients studied were taken from 1,456 consecutive admissions to the ICU; all had pneumonia, peritonitis, or sepsis of unknown origin. Between the two years of the study, no differences were noted in the patients’ mean APACHE II score, age, overall need for antibiotics, or duration of therapy. However, antibiotic rotation was associated with a marked decrease in the rate of resistant gram-positive coccal and gram-negative bacillary infections. For example, there were 7.8 resistant gram-positive coccal infections per 100 admissions among the patients treated with the rotated antibiotics, compared with 14.6 such infections per 100 admissions in the other group.

Resistant gram-negative bacillary infections occurred in 2.5 and 7.7 per 100 patients, respectively. Mortality related to infection was also reduced; there were 2.9 deaths per 100 admissions in the patients given rotated antibiotics, compared to 9.6 deaths per 100 admissions in the other group. The researchers concluded that although further research was needed to determine the long-term efficacy of antibiotic rotation, it was clear in this case that it reduced infection and related mortality without increasing medication costs.

Raymond DP, Pelletier SJ, Crabtree TD, et al. Impact of a rotating empiric antibiotic schedule on infectious mortality in an intensive care unit. Crit Care Med. 2001;29:1101-1108.