Respiratory illness, beta-agonists, and risk of idiopathic dilated cardiomyopathy. The Washington, DC, Dilated Cardiomyopathy Study.

An epidemiologic study was carried out to examine the possible role of beta-agonists and other respiratory medications in the development of idiopathic dilated cardiomyopathy. Associations with respiratory medications, bronchial asthma, emphysema, and chronic bronchitis were examined by comparing newly diagnosed cases (n = 129) ascertained from five Washington, DC, area hospitals for the period 1990-1992 with neighborhood controls (n = 258) identified by using a random digit dialing technique. The cases and controls were matched on sex and 5-year age intervals and were compared in the analysis using conditional logistic regression methods. A statistically significant association was observed between idiopathic dilated cardiomyopathy and history of emphysema or chronic bronchitis (adjusted odds ratio (OR) = 4.4, 95% confidence interval (CI) 1.6-12.4). The association with bronchial asthma was of borderline significance (adjusted OR = 1.9, 95% CI 0.9-4.2). Associations were also observed with use of oral beta-agonists (adjusted OR = 3.4, 95% CI 1.1-11.0) and beta-agonist inhalers or nebulization (adjusted OR = 3.2, 95% CI 1.4-7.1), as well as with use of oral corticosteroids, inhaled corticosteroids or cromolyn, and theophylline medications. A total of 20.0% (23 of 115) of the cases had a reported history of beta-agonist inhaler use compared with 6.7% (17 of 254) of the controls. The strength of these associations was diminished when the temporal relation between exposure to beta-agonist inhalers or oral preparations and clinical diagnosis of idiopathic dilated cardiomyopathy was taken into account, however, and the associations with duration of beta-agonist medication use were not statistically significant (p > 0.05). The results of this study suggest, but do not prove, that use of beta-agonists has an etiologic role in idiopathic dilated cardiomyopathy.

Analgesia, sedation and paralysis in the intensive care unit.

Patients admitted to the intensive care unit often experience some degree of pain and frequently are anxious, confused or delirious. Relief of pain, anxiety and agitation is important for effective patient care. Initial attention should be directed toward eliminating organic causes of delirium. Opioids are the cornerstone of analgesia, while benzodiazepines and haloperidol are commonly used for sedation and relief of agitation. When sedative agents fail to control agitation and effective ventilation of the patient is compromised, it may be appropriate to pharmacologically paralyze the patient.

Attended home titration of nasal continuous positive airway pressure therapy for obstructive sleep apnea.

Nasal continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea (OSA) is usually titrated in a sleep laboratory with full polysomnographic monitoring until apneas, nonapneic desaturation, snoring, and microarousals are eliminated. This titration is sometimes done in the second half of the diagnostic sleep study or commonly on a separate second full night in the sleep laboratory. We performed NCPAP titration in the home in 17 patients with OSA previously documented by full polysomnography. Nasal CPAP was titrated at night in the patient's home by a registered nurse or polysomnography technician monitoring real-time recordings of heart rate, thoracic impedance, oxygen saturation, and pressure at the nasal mask on a four-channel recorder (EdenTec, Eden Prairie, Minn). Recordings of the nasal CPAP titration night were reviewed later by a physician. Apneas, hypopneas, and snoring were successfully eliminated in all patients. Mean nasal CPAP pressure was 10.3 +/- 3.2 cm H2O. At the time of a follow-up interview, 13 of 17 patients continued to be compliant with nasal CPAP therapy. The mean duration of therapy was 13.4 +/- 11.7 months with 7.23 mean hours of use for 6.76 nights per week. This compliance compares favorably with long-term home nasal CPAP compliance previously reported in patients titrated in our sleep laboratory. Home nasal CPAP titration resulted in about a $600 savings per patient.

Differential lobe lavage for diagnosis of acute Pneumocystis carinii pneumonia in patients receiving prophylactic aerosolized pentamidine therapy.

The diagnostic yield of bronchoalveolar lavage (BAL) for Pneumocystis carinii pneumonia (PCP) in patients infected with human immunodeficiency virus has been reported to be 95 percent, but falls to 62 percent in patients receiving aerosolized pentamidine. Because aerosolized pentamidine appears to be preferentially deposited in the middle and lower lobes, we postulated that an upper lobe lavage would have a higher diagnostic yield than the standard middle/lower lobe lavage in patients receiving aerosolized pentamidine. Twenty-five patients receiving aerosolized pentamidine suspected of having acute PCP underwent separate BAL of an upper lobe and lower lobe as well as transbronchial biopsy. Fifteen of the 25 (60 percent) were diagnosed as having PCP. Of the 15, one had the samples inadvertently combined. In the remaining 14, BAL was positive for P carinii organisms in 12 lavages of the lower lobe and 14 of the upper lobe. Upper lobe lavage had statistically significantly more P carinii organisms by semiquantitative technique than the lower lobe. In patients receiving aerosolized pentamidine, who develop acute PCP, an upper lobe lavage may have a higher diagnostic yield than the standard middle/lower lobe lavage. In addition, the transbronchial biopsy specimen offered no treatable diagnosis that was not made by lavage alone in the 25 patients. This raises the question of the utility of transbronchial biopsies in these patients.

Nocturnal nasal intermittent positive pressure ventilation with bi-level positive airway pressure (BiPAP) in respiratory failure.

The purpose of this study was to assess the efficacy of bi-level positive airway pressure (BiPAP) ventilation through a nasal mask in the treatment of eight patients with hypoventilatory respiratory failure and nocturnal CO2 retention. Nocturnal CO2 retention was significantly reduced in all patients with the application of BiPAP during sleep (p less than 0.01). Daytime somnolence was relieved and dyspnea improved after three months of home BiPAP therapy. All patients tolerated home BiPAP therapy, and two patients who had previously been treated with volume ventilation via nasal mask found BiPAP more comfortable. There were no changes in FEV1 or FVC after three months of BiPAP. Daytime PaCO2 improved slightly or remained stable in all patients after three months of home BiPAP. BiPAP nasal ventilation is effective in reducing nocturnal CO2 retention short term in hypoventilatory respiratory failure due to obesity hypoventilation syndrome, chest wall restriction, or neuromuscular disease. Further studies in patients with COPD may be warranted.

Validation of sleep observations in a nursing home.

Most of the studies on sleep patterns in elderly people have been performed on small samples in sleep laboratories and with the use of advanced technology. Such technology is generally unavailable either for research studies or clinical interventions with elderly people residing in the community. Additionally, the utility of the sleep laboratory in assessing sleep in the very demented patient is limited because of irregularities of electroencephalogram (EEG) patterns in this population. For these reasons, systematic sleep observations are presented as important tools in the assessment of sleep in the nursing home. Nursing homes have night-shift staff who are frequently not fully occupied and could be trained to perform sleep observations. The Observational Sleep Assessment Instrument (OSAI) documents the occurrence of sleep, as well as disruptions in sleep, breathing, snoring, myoclonic movements, and body restlessness. This study documented the validity of the OSAI by establishing interrater reliability and by correlating its results to those of a portable sleep monitor, namely, a four-channel ambulatory sleep respiratory monitor and a wrist activity monitor. Results show that the OSAI is a reliable and valid tool for examining sleep and sleep pathology in this population, and can become a useful screening tool for detecting sleep and breathing disorders.

Postpartum subcutaneous emphysema with pneumomediastinum.

We have presented a case of pneumomediastinum and subcutaneous emphysema in a 30 year old woman immediately post-partum. The underlying pulmonary pathophysiology and management are discussed.

Long-term compliance with nasal continuous positive airway pressure therapy of obstructive sleep apnea.

In an attempt to identify predictors of long-term compliance with nasal continuous positive airway pressure (CPAP), we reviewed the records of 125 patients with obstructive sleep apnea (OSA) referred to our center for nasal CPAP trials. Severity of sleep apnea, sleep staging, daytime hypersomnolence, effectiveness of nasal CPAP, previous palatal surgery, and adverse reactions were compared in compliant and noncompliant patients. Nineteen patients did not tolerate a nasal CPAP trial in the laboratory or refused home nasal CPAP therapy. Ten patients were unavailable for follow-up. Of the remaining 96 patients, 23 (24 percent) had discontinued therapy, while 73 (76 percent) were still using nasal CPAP at 14.5 +/- 10.7 months (mean +/- SD). There were no statistically significant differences between the compliant and noncompliant patients in baseline apnea plus hypopnea index (AHI), baseline sleep staging, AHI while receiving nasal CPAP, sleep staging while receiving nasal CPAP, or frequency of adverse reactions during therapy. Severe daytime sleepiness was present in 65 of the 73 compliant patients and in 12 of the 23 noncompliant patients (p less than 0.05). Ten of 43 in the compliant group had previous palatal surgery compared with ten of 23 noncompliant patients (p less than 0.05). Our data confirm earlier observations in smaller samples that compliant and noncompliant patients have equally severe sleep apnea and good initial responses to nasal CPAP. Long-term compliance with nasal CPAP may be associated with the severity of daytime hypersomnolence on presentation. Previous palatal surgery was more frequent in patients who did not tolerate long-term nasal CPAP therapy.

Cerebral blood flow in humans following resuscitation from cardiac arrest.

Cerebral blood flow was measured by xenon-133 washout in 13 patients 6-46 hours after being resuscitated from cardiac arrest. Patients regaining consciousness had relatively normal cerebral blood flow before regaining consciousness, but all patients who died without regaining consciousness had increased cerebral blood flow that appeared within 24 hours after resuscitation (except in one patient in whom the first measurement was delayed until 28 hours after resuscitation, by which time cerebral blood flow was increased). The cause of the delayed-onset increase in cerebral blood flow is not known, but the increase may have adverse effects on brain function and may indicate the onset of irreversible brain damage.

Sleep apnea syndrome.

Sleep apnea syndrome is estimated to affect as many as 2 to 3 percent of the adult male population. Excessive snoring and daytime sleepiness are but a few of the many clues to diagnosis. The hypoxemia occurring as a result of apnea may lead to pulmonary hypertension. Depressed respiratory center neural output or upper airway occlusion during sleep may cause the apnea. There are a number of treatment options available.

Life-threatening bacterial pneumonia in male homosexuals with laboratory features of the acquired immunodeficiency syndrome.

Two male homosexuals with laboratory features of the acquired immunodeficiency syndrome developed fulminating pneumonia requiring mechanical ventilatory support despite antibiotic therapy. Pathology consistent with bacterial pneumonia without other opportunistic pathogens were found at open lung biopsy. Cultures from the open biopsy grew Hemophilus influenzae in one, and Streptococcus pneumoniae was seen on Gram stain and sputum culture prior to antimicrobial treatment in the other. Each recovered on continued single antibiotic therapy. Life-threatening bacterial pneumonia may be a feature of the acquired immunodeficiency syndrome, possibly due to B cell abnormalities.

Pulmonary venoocclusive disease in pregnancy.

A 23-year-old woman in her 27th week of gestation presented with clinical findings of progressive pulmonary hypertension. After cardiac catheterization she went into labor and was delivered by cesarean section. She died shortly thereafter from right heart failure. Pulmonary venoocclusive disease was found at autopsy. Hemodynamic changes during pregnancy, labor, delivery, and the postpartum period may have contributed to her deterioration and death. This is the first description of pulmonary venoocclusive disease in pregnancy.

Pulmonary veno-occlusive disease associated with microangiopathic hemolytic anemia and chemotherapy of gastric adenocarcinoma.

A 68-year-old man was treated with FAM (5-fluorouracil, doxorubicin [Adriamycin], mitomycin-C) for metastic gastric adenocarcinoma. Twelve months later while in complete clinical remission, pulmonary hypertension and microangiopathic hemolytic anemia were recognized, progressed, and ended in his demise 6 months later. At necropsy, minimal residual cancer and severe pulmonary veno-occlusive disease was found. Pulmonary veno-occlusive disease may occur in association with microangiopathic hemolytic anemia and cancer chemotherapy.

Invasive pulmonary aspergillosis associated with aspergilloma in sarcoidosis.

We have described two patients with corticosteroid-treated sarcoidosis and with autopsy-proven aspergilloma and diffuse invasive pulmonary aspergillosis. In one, growth of the fungus within a cyst was probably followed by progression to diffuse pulmonary infection. In the second, lung necrosis from invasive infection may have led to the formation of the mycetoma found at autopsy.