Nocturnal hypoxemia is common in primary pulmonary hypertension.

STUDY OBJECTIVE: Unsuspected sleep-related respiratory events are common in patients with severe pulmonary disease. Sleep in patients with primary pulmonary hypertension (PPH) has not been studied (to our knowledge). The purpose of this study was to measure the prevalence of respiratory disturbances and nocturnal hypoxemia during the sleep of patients with PPH. SETTING: Tertiary-care referral hospital. DESIGN: Retrospective review. PATIENTS: Thirteen patients with PPH. MEASUREMENTS: All patients underwent a single-night comprehensive polysomnogram study. Patients who spent > 10% of the total sleep time with oxygen saturation by pulse oximetry (SpO(2)) at < 90% or who needed oxygen to maintain their SpO(2) level at > 90% were classified as nocturnal desaturators. Analysis was performed to determine which clinical variables (ie, demographics, body mass index, spirometry, diffusion capacity, right heart catheterization pressures, 6-min walk test, arterial blood gas levels, resting and walking SpO(2) levels, and polysomnogram variables) would predict nocturnal desaturation. Statistical significance was considered when p values were < 0.05. RESULTS: Of the 13 patients in the study, 10 (77%) were nocturnal desaturators. All patients had normal apnea indexes, but two had mild elevations of the hypopnea index (< 15 episodes per hour). Nocturnal desaturations occurred independently of apneas or hypopneas. Six patients who did not have O(2) titration during sleep spent > 25% of sleep time with SpO(2) < 90%. The mean (+/- SD) variables that were significantly different between desaturators (10 patients) and nondesaturators (3 patients) were FEV(1) (70.1 +/- 9.1% predicted vs 98.1 +/- 15.1% predicted, respectively; p = 0.002), resting PaO(2) (61.8 +/- 16.1 vs 90.3 +/- 2.3 mm Hg, respectively; p = 0.001), alveolar-arterial oxygen pressure difference (P[A-a]O(2)) (40.5 +/- 20.5 vs 12.2 +/- 7.2 mm Hg, respectively; p = 0.048), resting SpO(2) (91.6 +/- 5.4% vs 98.7 +/- 2.3%, respectively; p = 0.038), and walking SpO(2) (83.8 +/- 9.3% vs 95.3 +/- 1.2%, respectively; p = 0.002). The mean hemoglobin level was higher in the group of nocturnal desaturators than in the group of nondesaturators (10.43 +/- 0.31 vs 13.95 +/- 0.98 g/dL, respectively; p < 0.0001). CONCLUSION: Seventy-seven percent of patients with PPH have significant nocturnal hypoxemia that is unrelated to apneas and hypopneas. Nocturnal desaturation occurs more frequently in patients with higher P(A-a)O(2) values and lower FEV(1) values, resting arterial PaO(2) and SpO(2) values, and walking SpO(2) values.

An arrhythmia detector and heart rate estimator for overnight polysomnography studies.

We present an algorithm for automatic on-line analysis of the electrocardiography (ECG) channel acquired during overnight polysomnography (PSG) studies. The system is independent of ECG morphology, requires no manual initialization, and operates automatically throughout the night. It highlights likely occurrences of arrhythmias and intervals of bad signal quality while outputting a continual estimate of heart rate. Algorithm performance is validated against standard ECG databases and PSG data. Results demonstrate a minimal false negative rate and a low false positive rate for arrhythmia detection, and robustness over a wide range of noise contamination.

The polysomnogram assay: a method to represent the overnight polysomnogram in a condensed format.

We present the polysomnogram assay (PSGA), a new representation format for the polysomnogram (PSG), designed to assist in the interpretation of overnight PSG studies. The technique condenses the PSG record by a factor of 30 while preserving the ability to portray PSG features of diagnostic relevance, including sleep architecture, arousals, movement, leg jerks, cyclic alternating pattern, and increased breathing effort. The PSGA patterns associated with these events are described and illustrated by examples. The new format considerably reduces the effort required to evaluate sleep quality and continuity, making it more practicable for the polysomnographer to interpret the entire overnight PSG study. The compressed time scale also facilitates analysis of relatively long PSG episodes and allows assessment of signal activity surrounding critical PSG events. The PSGA appears capable of improving identification of arousals, leg jerks, and upper airway resistance, and may be especially amenable for automatic analysis of PSG data.

Aortopulmonary fistula in an infected Dacron graft for coarctation of the aorta: an uncommon cause of hemoptysis.

Hemoptysis secondary to an aortobronchial fistula is rare and uniformly fatal when left untreated. The authors describe a case of massive hemoptysis caused by an aortopulmonary fistula in an infected Dacron graft used successfully to repair a coarctation of the aorta.

Clinical management of asthma in the 1990s. Current therapy and new directions.

Asthma is a serious global health problem affecting nearly 100 million people worldwide. Its rising prevalence and associated morbidity and mortality are of increasing concern. Traditionally, symptomatic control of bronchoconstriction with beta 2 agonists and theophylline has been the mainstay of therapy. However, during recent years, inflammation has been recognised as the predominant cause of reversible airway obstruction and airway hyperreactivity. As a result, the emphasis in treatment has shifted to the early use of inhaled corticosteroids to control airway inflammation. beta 2 agonists are best used on an as-needed basis for the relief of acute bronchoconstriction and for the prevention of exercise-induced asthma. Sustained release theophylline or an inhaled long-acting beta 2 agonist may effectively control nocturnal symptoms. Preliminary studies involving agents active in the 5-lipoxygenase pathway as preventive therapy are encouraging. Further studies are needed to define their role in the management of asthma.

Dynamic pharyngoscopy in predicting outcome of uvulopalatopharyngoplasty for moderate and severe obstructive sleep apnea.

STUDY OBJECTIVE: We sought to determine whether preoperative fiberoptic pharyngoscopy (FOP) with Müller's maneuver (dynamic FOP) could be used to establish a subgroup of obstructive sleep apnea (OSA) patients with better outcome after uvulopalatopharyngoplasty (UPPP). DESIGN: Retrospective review of an observational cohort. SETTING: Tertiary care referral center. PATIENTS: Twenty-nine patients who underwent UPPP and nasopharyngeal surgery by one surgeon. INTERVENTION: The patients were divided into two groups based on the findings of preoperative dynamic FOP: group 1 (11 patients) had collapse of the velopharynx and the base of the tongue-epiglottis-hypopharynx (TEH) complex and group 2 (18 patients) had velopharyngeal collapse only. MEASUREMENTS AND RESULTS: Surgical success was defined using a conventional definition (> 50% reduction in the apnea-plus-hypopnea index [OAHI]), and a criterion for cure (> 90% reduction in OAHI and postoperative OAHI < 15). Both groups had a significant improvement in their OAHI. The success rate was significantly higher in patients with velopharyngeal collapse only compared with patients with additional collapse of the TEH complex (78 vs 36% with the conventional definition, and 50 vs 9% using the definition for cure, respectively). Predictive value of dynamic FOP in predicting cure failure when collapse of the TEH complex was present was 91%. CONCLUSIONS: Dynamic FOP may help establish a subgroup of OSA patients with greater likelihood of successful UPPP. The high negative predictive value of dynamic FOP when a criterion for cure is used suggests that this maneuver could best be used to exclude patients with TEH complex collapse from UPPP.

Obstructive sleep apnea. Warding off the sometimes dire consequences.

Obstructive sleep apnea (occlusion of the upper airway despite continued respiratory muscle activity) is accompanied by increased morbidity and mortality from cardiovascular and cerebrovascular disease. Daytime sleepiness due to the disorder may also be a factor in a higher incidence of automobile accidents in these patients. An overnight polysomnogram is used to confirm the diagnosis and assess severity of physiologic disturbances. Initially, simple measures, such as avoidance of alcohol and sedatives before bedtime and sleeping on the side rather than the back, may be tried. Nasal continuous positive airway pressure is considered first-line therapy, and compliance can be improved by education and counseling of the patient. Uvulopalatopharyngoplasty is beneficial in only 50% of patients. Tracheostomy gives the most consistent long-term benefit but is accompanied by significant emotional morbidity.

Changing strategies in the management of asthma.

Mortality from asthma is apparently on the rise and, in some cases, may be due to the type and amount of medication used by the patient. As a result, the role of some commonly prescribed agents has changed in recent years. In this article, the authors review modifications in the use of currently available drugs, discuss new applications of drugs not traditionally used for asthma, and examine the rationale behind the development of entirely new classes of drugs.

Women and lung cancer: a comparison of active and passive smokers with nonexposed nonsmokers.

Prior to the 1920s, lung cancer was a rare disease. However, the current increase in lung cancer appears to parallel the increase in smoking for both men and women with a 30- to 50-year delay. National lung cancer deaths continue to rise, with over 168,000 total deaths estimated in 1992. Women are now showing higher percentage increases in lung cancer than men from active smoking. The data from the Erie County Study on Smoking and Health (ECSSH), a population study, were used to measure the effects of both active and passive smoking on women's lung cancer mortality. The three major categories of exposure (no known or minimal exposure, passive smoking exposed, and active smoking) were used in the analyses. The results from the population data in Erie County, PA, were based on 528 nonexposed nonsmoking women, 3138 exposed nonsmoking women, and 1747 smoking women. Deaths due to lung cancer as a percentage of total deaths excluding traumatic deaths were 0.2% for the nonexposed nonsmoking women, 0.9% for the exposed nonsmoking women, and 8.0% for women who smoked. The data showed that women smokers died of lung cancer at a rate 9 times greater than exposed nonsmokers and 42 times greater than nonexposed nonsmokers.

Giant esophageal varices. An unusual cause of a posterior mediastinal mass.

Esophageal pathology rarely presents as posterior mediastinal abnormalities on chest roentgenograms, with the most common being hiatal hernia. We describe a patient with giant esophageal varices manifesting as a retrocardiac, posterior mediastinal mass.

A physician's guide to smoking cessation.

Claims of the effectiveness of smoking cessation services and products are often misleading. It is important that physicians be well informed in order to make appropriate recommendations to their patients who smoke. In this article smoking cessation products and programs are critically evaluated and issues such as cure rates and validation of self-reported abstinence are discussed. Many commercial products are available to aid in cessation, although none has been proven effective. With the exception of nicotine polacrilex gum and transdermal patches in conjunction with a multicomponent clinic, medications are generally ineffective. Smoking cessation programs range from the provision of self-help materials to multisession groups and clinics. Multicomponent, behavioral-based group programs have been the most successful. Physicians should raise the issue of smoking cessation as frequently as possible with smokers and should recommend the use of smoking cessation products and services as appropriate. Referrals should be made to programs that base their success rates on scientifically accepted standards, including a 1-year follow-up, inclusion of dropouts and nonrespondents in calculating outcome, and biochemical validation of self-reported abstinence. Reports of success rates of 80% to 95% at the end of a 1-year program should be viewed with skepticism. Ideally, whether working independently or through referral, the physician should actively promote smoking cessation for all patients who smoke.

Massive air embolism complicating Nd-YAG laser endobronchial photoresection.

A 63 year old male underwent 6,900 rads of external radiation for a squamous cell carcinoma of the left main bronchus. Recurrence of the tumor 8 months later was treated with 6,618 joules and patency of the left main bronchus was restored. Four months later, he developed complete atelectasis of the left lung requiring repeat laser. During the procedure he became hypotensive, bradycardic, and hypoxic due to a tension pneumothorax. Although treated promptly with thoracostomy tube drainage, the patient never awakened. CT scan of the brain demonstrated anoxic encephalopathy with air present in the right frontal lobe. Brain death was confirmed by an EEG and cerebral angiogram. Air embolism has been reported in conjunction with diagnostic procedures including therapeutic pneumothorax for tuberculosis, transthoracic needle biopsy of the lung, and positive pressure ventilation with or without pneumothorax. The only reported case of air embolism associated with laser was a small middle cerebral artery cerebro-vascular accident which was self limited. Its mechanism is unclear, but it is suspected to be due to a communication between a pulmonary vein and the atmosphere. A greater volume of air will enter the damaged vessel in the setting of positive pressure ventilation and/or a tension pneumothorax. When neurologic manifestations are present, hyperbaric oxygen therapy is the treatment of choice. Prompt institution in hemodynamically stable patients can minimize neurologic sequelae.

Quantitation of abnormal 67Ga uptake in pulmonary interstitial vascular disease--a new test to detect diffuse lung disease.

Gallium 67 has been used as a modality to diagnose and follow the clinical course of diseases such as tumors, infections, inflammatory disorders, and interstitial lung disease. It has been appreciated, however, that mild to moderate changes in scan activity, when these disorders are followed over time, are less than optimal. SPECT (single-photon emission computed tomography) scanning is a new technique designed to obviate this problem. SPECT scanning utilizes computer acquisition to provide three-dimensional scanning and the additional benefit of colorization to aid in discerning differences of uptake. SPECT scanning was performed on 22 patients with interstitial lung disease of various etiologies. Additionally, 7 patients had follow-up SPECT scanning to determine their response to treatment. Two patients are presented as examples.

Survival experience following Nd:YAG laser photoresection for primary bronchogenic carcinoma.

We followed the course of 47 consecutive patients with inoperable primary bronchogenic carcinoma who underwent palliative neodymium-yttrium-aluminum-garnet laser photoresection (YPR) between September 1983 and September 1986. Of these 47, 35 (74.5 percent) underwent both radiation therapy (XRT) and YPR. The survival of these 35 patients (median survival, 304 days) was compared with that of 58 who underwent only palliative palliative XRT (median survival, 253 days) from 1981 to 1983, when YPR was not yet available at our institution. There was no significant difference in overall survival (p = 0.17). A significant increase in survival (p = 0.04) was seen in 15 patients who underwent emergency palliative YPR as the initial therapeutic intervention compared with 11 patients who received emergency palliative XRT but would have received YPR had it been available at that time. A trend toward increased survival was also shown in patients who underwent endobronchial radiation therapy in addition to YPR and XRT.

Bronchopulmonary endometriosis: a rare cause of hemoptysis.

We have reported a case of hemoptysis caused by pulmonary parenchymal endometriosis which was apparently successfully treated with danazol. Bronchopulmonary endometriosis is a very unusual cause of hemoptysis, and should be suspected on the basis of cyclic hemoptysis with menstruation. Danazol is effective therapy, but information regarding optimal dosage and rates of recurrence after completion of therapy is limited at this time.