Reverse halo sign on chest imaging in a renal transplant recipient.

Without proper treatment, the mortality of pulmonary mucormycosis is nearly 100%. Although the diagnosis is often made histologically, it can be suspected when patients have a reverse halo sign on computed tomography (CT) of the chest, along with the right clinical findings. We describe the case of a woman 7 months post renal transplant who presented with fevers, malaise, and chest pain. Her chest CT revealed a round, focal area of ground-glass attenuation surrounded by a complete rim of consolidation in the left upper lobe, consistent with the reverse halo sign. Pulmonary mucormycosis was diagnosed by transbronchial lung biopsy. She was successfully treated with combined medical and surgical therapies. In the context of this case, we provide a brief review of the diagnosis of pulmonary mucormycosis, with a focus on radiographic and pathologic findings.

Weaning from mechanical ventilation: an update.

Many patients admitted to the intensive care unit have respiratory failure and thus require mechanical ventilation. Weaning patients from mechanical ventilation after their primary disease process has been treated can be difficult in approximately 30% of patients. Inadequacies in pulmonary gas exchange and in the performance of the respiratory muscle pump are the most common causes for failure to wean. Assessing whether a patient can be weaned from mechanical ventilation involves two major factors: (1) examining the patient for evidence of an increase in the work of breathing, and (2) measuring spontaneous breathing variables. Although different modalities have been used in weaning patients from mechanical ventilation, none has been shown to be more successful than repeated trials of spontaneous breathing.

Circadian rhythm sleep disorders.

"Night owls" and "morning larks" are descriptive terms used to characterize individuals who go to sleep or awaken differently than most individuals. Many of these individuals have a primary circadian sleep dysrhythmia. Identification and proper treatment of a specific condition can markedly improve their quality of life. Secondary circadian dysrhythmias are very common. Nearly everyone at some time in his or her life experiences jet lag or shift work sleep disorder, two conditions in which we ignore our biologic rhythms. The impact of these conditions on performance and judgment can be tempered by certain pharmacologic and nonpharmacologic strategies. A better understanding of both primary and secondary circadian rhythm sleep disorders will be valuable to the primary care physician, leading to earlier diagnosis and improved treatment of patients with these conditions.

Comparison of oxygen therapy with nasal continuous positive airway pressure on Cheyne-Stokes respiration during sleep in congestive heart failure.

STUDY OBJECTIVES: Both oxygen therapy and nasal continuous positive airway pressure (CPAP) therapy have independently been shown to be effective in the treatment of Cheyne-Stokes respiration (CSR) in patients with congestive heart failure (CHF). The purpose of this study was to compare the short-term effects of oxygen therapy and nasal CPAP therapy on CSR in a group of stable patients with severe CHF. DESIGN: Prospective, randomized, controlled trial. SETTING: University hospital. PATIENTS: Twenty-five stable patients (mean [+/- SD] age, 56 +/- 9) with CHF and a mean left ventricular ejection fraction (LVEF) of 17 +/- 0.8%. INTERVENTIONS AND MEASUREMENTS: All patients had a right heart catheterization prior to the study and an echocardiogram performed to measure LVEF. In addition, all patients had an initial sleep study to identify the presence of CSR. Sleep studies included continuous recordings of breathing pattern, pulse oximetry, and EEG. Those patients identified as having CSR were randomized to a night on oxygen therapy (2 L/min by nasal cannula) and another night on nasal CPAP therapy (9 +/- 0.3 cm H(2)O). RESULTS: Fourteen of the 25 patients (56%) studied had CSR (apnea hypopnea index [AHI], 36 +/- 7 events per hour) during their initial sleep study. Nine of the 14 patients with CSR completed the study. When compared with baseline measurements, both oxygen therapy and nasal CPAP therapy significantly decreased the AHI (from 44 +/- 9 to 18 +/- 5 and 15 +/- 8 events per hour, respectively; p < 0.05), with no significant difference between the two modalities. The mean oxygen saturation increased significantly and to a similar extent with oxygen therapy and nasal CPAP therapy (from 93 +/- 0.7% to 96 +/- 0.8% and 95 +/- 0. 7%, respectively; p < 0.05), as did the lowest oxygen saturation during the night (from 80 +/- 2% to 85 +/- 3% and 88 +/- 2%, respectively; p < 0.05). In addition, the mean percent time the oxygen saturation was < 90% also improved with both interventions (from a baseline of 17 +/- 5 to 6 +/- 3% with oxygen therapy and 5 +/- 2% with nasal CPAP therapy; p < 0.05). When compared with baseline measurements, the apnea-hypopnea length, cycle length, circulation time, and heart rate did not significantly change with either oxygen therapy or nasal CPAP therapy. Total sleep time and sleep efficiency decreased only with nasal CPAP therapy (from 324 +/- 20 to 257 +/- 14 min, and from 82 +/- 3 to 72 +/- 2%, respectively; p < 0.05). The arousal index, when compared with baseline, remained unchanged with both oxygen therapy and nasal CPAP therapy. CONCLUSION: CSR occurs frequently in stable patients with severe CHF. In addition, oxygen therapy and nasal CPAP therapy are equally effective in decreasing the AHI in those CHF patients with CSR.

Circadian rhythms in the pharmacokinetics and clinical effects of beta-agonist, theophylline, and anticholinergic medications in the treatment of nocturnal asthma.

Published asthma consensus reports now acknowledge that asthma is a nocturnal disease in as many as 75% of those afflicted by this medical condition. Nonetheless, the treatment of this chronic obstructive pulmonary disease in the clinic continues to be based primarily on homeostatic considerations in that it relies on long-acting bronchodilator and other therapies formulated and scheduled to ensure constant or near-constant levels of medication during the 24h. The need of asthma patients prone to nighttime attacks is not the same during the day and night; the therapeutic requirements of patients who experience nocturnal asthma, especially ones with the more severe forms of the disease, are often not satisfied by conventional medications. The therapeutic response and patient tolerance to bronchodilator medications can be improved markedly when the medications are proportioned during the 24h as a chronotherapy, that is, when more medication is delivered during nighttime sleep than daytime activity, as verified by numerous studies. This article reviews how the body's circadian rhythms influence the pharmacokinetics and effects of commonly prescribed asthma therapies and addresses why and how they must be taken into consideration to increase the effectiveness of asthma treatment.

Salmeterol: a long-acting beta 2-agonist.

Salmeterol xinafoate is a potent and highly selective beta 2-adrenoreceptor agonist with a duration of action greater than 12 hours. When inhaled twice daily in the management of chronic asthma, it results in improved lung function, reduces acute asthmatic exacerbations, and improves the patient's quality of life. This agent has shown particular benefit for patients who continue to have symptomatic asthma despite the regular use of inhaled corticosteroid therapy and the frequent use of a short-acting beta 2-agonist. Although there is some evidence that salmeterol induces some tolerance to the bronchoprotective effect of beta 2-agonist therapy, improvement in lung function and asthma symptoms scores, during both the daytime and nighttime, are sustained. Importantly, patients must be educated in the proper use of salmeterol; for many asthmatics, this medication should be administered with inhaled or oral corticosteroid therapy, and salmeterol should not be used for rescue bronchodilation. When used properly, salmeterol is an effective and safe adjunctive therapy in the management of chronic asthma in adolescents and adults.

Exercise-induced bronchospasm in high school athletes via a free running test: incidence and epidemiology.

BACKGROUND: Exercise-induced bronchospasm (EIB) affects up to 35% of athletes and up to 90% of asthmatics. Asthma morbidity and mortality have increased over the past several decades among residents of Philadelphia, PA. It is possible that a simple free running test for EIB may serve as a tool to study the factors contributing to recent trends in asthma, and to screen for asthma in athletes in the urban setting. OBJECTIVES: The purposes of this study were to (1) assess a free running test to screen for EIB, and (2) examine prevalence of and epidemiologic factors associated with EIB in high school athletes. DESIGN: Cross-sectional observational study on the incidence and risk factors for EIB. To validate our method and criteria for the diagnosis of EIB, a repeat test was performed on a portion of the athletes. In a randomized single-blinded fashion, 15 athletes who had demonstrated EIB initially received albuterol or placebo prior to a repeat exercise test. SETTING: Community high school athletic facilities. PARTICIPANTS: We studied 238 male high school varsity football players. INTERVENTION: All athletes underwent an acquaintance session with a questionnaire, followed by a 1-mile outdoor run (6 to 8 mins). MEASUREMENTS: Peak expiratory flow (PEF) measurements were determined prior to and 5, 15, and 30 min after exercise. Heart rates (HRs) and dyspnea scores were measured. EIB was defined as a decrease of 15% in PEF at any time point after exercise. Associations of EIB with demographic factors were assessed by univariate and multivariate analyses. RESULTS: Two hundred thirty-eight athletes participated: 92 European-Americans (EA), 140 African-Americans (AA), 5 Hispanics, and 1 Native American. Mean age was 16+/-1 years. Average HR postexercise was 156+/-24 beats/min. Twenty-four (10%) reported a history of treated asthma. The prevalence of EIB among the remaining 214 athletes was 19 of 214 (9%). The rate of EIB among AA athletes was higher than among EA athletes: (17/126 [13%] AA vs 2/82 [2%] EA, p = 0.01). During the validation portion of the study, the placebo-treated group (n = 7) demonstrated a consistent drop in PEF after exercise on repeat testing, with a 16+/-5% fall in PEF on initial testing and a 14+/-13 drop with placebo. In contrast, the fall in airflow in the albuterol-treated athletes (n = 8) following exercise reversed with albuterol treatment, from a 15+/-6% fall in PEF at initial testing to an increase in PEF of 6+/-9% from baseline following albuterol administration. A history of wheezing (p < 0.001), residence in a poverty area (p < 0.0001), race (p = 0.01), remote history of asthma (p < 0.001), and absolute water content of the air on the day tested (p = 0.04) were significantly associated with EIB. By stepwise regression, EIB was most closely associated with a history of wheezing (p = 0.001) and poverty area residence (p = 0.003). CONCLUSIONS: Our findings indicate a substantial rate of unrecognized EIB exists among urban varsity athletes, and suggest that active screening for EIB, especially for students residing in poverty areas, may be indicated to identify individuals at risk for EIB and asthma.

Salmeterol in the treatment of chronic asthma.

Salmeterol is a highly selective beta 2-adrenoreceptor agonist with a long duration of action--as long as 12 hours or more. When inhaled twice daily in the management of chronic asthma, salmeterol can improve lung function and the quality of life for patients with asthma, and reduce acute asthma exacerbations. It is also a useful adjunct in the treatment of exercise-induced asthma and nocturnal asthma. In patients who continue to have symptomatic asthma despite the regular use of an inhaled corticosteroid, salmeterol acts as a secondary controller of symptoms and reduces the need for inhaled short-acting beta 2-agonist "rescues". Since salmeterol is different from other beta 2 agonists, patients must be carefully educated in its proper use. Salmeterol should be administered in combination with an inhaled anti-inflammatory medication as adjunctive therapy, but it should not be used for rescue bronchodilatation.

Cheyne-Stokes respiration during sleep in congestive heart failure.

Cheyne-Stokes respiration (CSR) is a form of sleep-disordered breathing seen in approximately 40% of congestive heart failure patients with a left ventricular ejection fraction of < 40%. It is characterized by a crescendo-decrescendo alteration in tidal volume separated by periods of apnea or hypopnea. Sleep is generally disrupted, often with frequent nocturnal arousals. Clinical features include excessive daytime sleepiness, paroxysmal nocturnal dyspnea, insomnia, and snoring. Proposed mechanisms include the following: (1) an increased CNS sensitivity to changes in arterial PCO2 and PO2 (increased central controller gain); (2) a decrease in total body stores of CO2 and O2 with resulting instability in arterial blood gas tensions in response to changes in ventilation (underdamping); and (3) an increased circulatory time. In addition, hyperventilation induced hypocapnia seems to be an important determinant for the development of CSR. Mortality appears to be increased in patients with CSR compared to control subjects with a similar degree of left ventricular dysfunction. Therapeutic options include medically maximizing cardiac function, nocturnal oxygen therapy, and nasal continuous positive airway pressure. The role that other therapeutic modalities, such as inhaled CO2 and acetazolamide, might have in the treatment of CSR associated with congestive heart failure has yet to be determined.

Theophylline revisited.

For over 50 years, theophylline has been used regularly for the management of chronic asthma. However, because of its perceived narrow therapeutic index and the fact that it has been considered a weak bronchodilator, the use of theophylline therapy has diminished. Furthermore, with the introduction of newer pharmacologic agents and recommendations in widely accepted guidelines, both nationally and internationally, have further contributed to its decreased use. For years, theophylline has not only been considered a bronchodilator, but for many clinicians, an agent that could be used to enhance respiratory muscle function and mucociliary clearance and act at the level of the central nervous system to enhance ventilation. These properties were felt to be potentially useful for patients with severe exacerbated asthma. Recent studies have suggested that theophylline therapy can play a beneficial role in the management of both chronic stable asthma and exacerbated disease treated in the emergency department setting. Furthermore, a growing body of evidence suggests that theophylline has certain antiinflammatory and immunomodulating properties, even at plasma concentration levels below the accepted therapeutic range. If this is true, then theophylline may act best as a controller medication in the management of asthma. Because of its low cost and its ease of administration, theophylline therapy should be revisited and discussed as not only a reliever of bronchospasm, but a controller of chronic asthma.