High-resolution computed tomography was used to directly determine the short-term effects of intravascular volume expansion on airway caliber. The change in airway cross-sectional area caused by intravascular volume expansion (30 ml/kg, Ringer's lactate) was studied in six anesthetized mini-pigs within 5 min. Twenty-five of 27 large airways (diameter, 2.01 to 5.0 mm) demonstrated decreased internal cross-sectional area (10.56 +/- 1.26 vs 8.66 +/- 1.03 mm2, p < 0.001). Twenty of 24 small airways (diameter, 0.75 to 2.0 mm) showed decreased internal cross-sectional area (1.82 +/- 0.16 vs 1.44 +/- 0.16 mm2, p < 0.001). These changes were rapidly (< 6 min) reversed by intravascular volume reduction. The external airway cross-sectional area did not change. These data suggest rapid, reversible bronchial mucosal vascular engorgement as a cause of increased airway resistance in heart failure.

Several case reports have suggested that bronchogenic carcinoma occurs more frequently in young patients who are human immunodeficiency virus (HIV) seropositive. We investigated the incidence of bronchogenic carcinoma and its clinical presentations in young patients at risk for HIV infection. The tumor registry of Bellevue Hospital was reviewed, and 261 cases of bronchogenic carcinoma during the period from 1976 to 1979 (pre-AIDS period) and 232 during the period from 1987 to 1990 (AIDS period) were identified. These cases were stratified into age groups: 45 or younger, 46 to 55, 56 to 65, and 66 years or older. All patients aged 45 years or younger in the AIDS period were subdivided by HIV risk, and clinical characteristics were compared among the subgroups. Results revealed no increased incidence of bronchogenic carcinoma from the pre-AIDS period compared with the AIDS period. These results suggest that HIV seropositivity is not a risk factor for bronchogenic carcinoma.

Exercise-induced bronchospasm (EIB) is often inferred from the reduction after exercise in one arbitrarily selected value derived from the maximum expiratory flow-volume (MEFV) curve (eg, FEV1) on a single test; however, patients with symptoms of EIB not meeting these criteria may risk being undiagnosed. To assess the ability of repeated tests using additional MEFV parameters in identifying EIB-prone patients, we investigated the effects of exercise provocation on the MEFV curve on two separate occasions. Of 95 patients with symptoms of EIB, 61 had reproducible exercise-induced changes (< 10 percent intraresponse variation), falling into four patterns: 27 (44 percent) had significantly reduced VC and airflow throughout the MEFV curve; 18 (30 percent) had unchanged VC but decreased airflow throughout the curve; 11 (18 percent) had reduced airflow above 50 percent VC but not below 50 percent VC; and 5 (8 percent) had significant reductions in airflow only at 50 percent VC or below. Of the other 34 subjects, 18 had no apparent response, and 16 responded on only one occasion, making objective assessment of these patients' EIB equivocal. We conclude that for a given individual, failure to meet arbitrary criteria does not rule out EIB. Additionally, a more subjective approach that integrates, among other factors, all routine MEFV curve parameters taken from multiple tests with clinical symptoms and history provide a more accurate assessment of EIB.

Simple arm elevation results in increased metabolic and ventilatory requirements in patients with chronic airflow obstruction (CAO). These demands contribute to the dyspnea that is frequently reported when these patients perform activities of daily living involving the arms. We hypothesized that a comprehensive pulmonary rehabilitation (PR) program that includes upper extremity training would lower the ventilatory requirement for arm elevation. Metabolic and ventilatory responses to 2 min of simple arm elevation were studied in 14 patients with CAO before and after PR. Respiratory muscle strength was determined in 11 patients by measurement of maximal transdiaphragmatic pressure (Pdimax). Oxygen uptake (VO2), carbon dioxide production (VCO2), heart rate (HR), minute ventilation (VE), tidal volume (VT), and respiratory rate were measured at rest with the arms down and during 2 min of arm elevation. Before PR, arm elevation led to significant increases in VO2, VCO2, HR, and VE. After PR, pulmonary function, Pdimax, and resting metabolic and ventilatory parameters with the arms down were unchanged; however, during arm elevation, VO2, VCO2, and VE were significantly less than they were before PR. We conclude that a comprehensive PR program that includes upper extremity exercises leads to a reduction in the ventilatory requirement for simple arm elevation. This type of program may allow patients with CAO to perform sustained upper extremity activities with less dyspnea.

Tube thoracostomy is a standard therapy for a number of pulmonary disorders. The procedure is associated with a certain incidence of morbidity related to the technique of insertion, the patient population selected, and the length of time the tube remains in place. Complications of tube placement previously described include empyema, residual pneumothorax, lung perforation, placement of the tube in the chest wall, diaphragmatic perforation, perforation of intraabdominal organs (such as spleen, liver and stomach), unilateral pulmonary edema, bronchopleural fistula, hemothorax, cardiogenic shock and Horner syndrome. A case of a delayed pulmonary perforation developing several days after placement of a chest tube is described with a discussion of the clinical and radiographic findings associated with this complication. A possible pathophysiologic mechanism by which this complication may have occurred is proposed.

The frequency of adult surgical and medical intensive care unit (ICU) admissions related to substance abuse was determined at a large community, trauma, and tertiary referral hospital. Of 435 ICU admissions, 14 percent (95 percent confidence interval [CI], 5 to 23 percent) were tobacco related generating 16 percent of costs, 9 percent (95 percent CI, 0 to 18 percent) were alcohol related generating 13 percent of costs, and 5 percent (95 percent CI, 0 to 14 percent) were illicit drug related generating 10 percent of costs. In all, 28 percent (95 percent CI, 20 to 36 percent) of ICU admissions generating 39 percent of costs were substance abuse related. Substance abuse-related admissions were significantly longer and more costly than admissions not related to substance abuse (4.2 days vs 2.8 days, p = 0.004; $9,610 vs $5,890, p = 0.001). Frequency of substance abuse-related admission was linked with the patient's insurance status (Medicare, private insurance, uninsured). In the uninsured group, 44 percent of admissions were substance abuse related (95 percent CI, 35 to 52 percent), significantly higher than in the private insurance and Medicare groups, and generating 61 percent of all ICU costs in the uninsured group. Large fractions of adult ICU admissions and costs are substance abuse related, particularly in uninsured patients.

Lung cancer infrequently may be associated with human immunodeficiency virus (HIV) infection. This retrospective case-control study was undertaken to determine if there were differences in age, sex, and stage distribution and in survival between HIV-positive and HIV-indeterminate lung cancer patients. We compared 19 patients with both pathologically verified lung cancer and HIV infection proved by serologic study with lung cancer patients with an indeterminate HIV status. All 19 HIV-positive lung cancer patients were men. This was significantly (p = 0.004) different from the 69 percent male preponderance in 1,335 HIV-indeterminate lung cancer patients. Median ages of HIV-positive and HIV-indeterminate patients were 48 and 61 years, respectively. HIV-positive patients were significantly (p = 0.0139) younger. Stage distribution was similar in both groups. Histologic features and smoking were not significantly different between the two groups. Survival data that were available in 16 HIV-positive patients were compared with 32 HIV-indeterminate control subjects matched for stage, age, sex, and race. The median survival was three months in the HIV-positive group and ten months in the HIV-indeterminate cohort. The survival was significantly different (p = 0.002). There were no one-year survivors in HIV-positive lung cancer patients.

In this study, independent contribution of age, HR, BMI, casual and ambulatory blood pressure, LVM and LVEF in evaluating diastolic filling have been investigated in 34 never-treated hypertensive patients and in 15 healthy normotensive subjects. All the subjects were free from coronary artery disease, valvular disease, heart failure, renal disease and psychiatric problems. All the hypertensive subjects (never treated) were subgrouped according to presence or absence of LVH. The PFR decreased significantly and tPFR increased significantly in hypertensive patients in comparison with normotensive subjects and they did not change in the presence vs absence of LVH. The PFR was inversely correlated with BMI, age, 24-h mean SBP and with 24-h DBP. In multiple regression analysis, PFR decreased with BMI, age, 24-h mean SBP and DBP but not with LVMI. These results suggest that BMI, age and 24-h mean blood pressure were the major determinants of PFR abnormalities in hypertensive patients.

Obstructive sleep apnea syndrome (OSAS) and heavy snoring during sleep, without sleep apnea, has been well described in children and adults. We report a case series of 25 full-term infants, prospectively obtained from a database of nearly 700 "apparent life-threatening event" (ALTE) cases, who presented between 3 weeks and 4 1/2 months of age an ALTE and who progressively developed more florid symptomatology and polygraphic findings. All of them were classified as OSAS patients by five years of age. These index cases are compared with two other ALTE infant groups followed in parallel during the first year of life but whose symptoms were short-lived. The index cases presented more frequently a positive family history of OSAS and an early report of snoring or noisy breathing during sleep. Usage of an esophageal balloon to monitor esophageal pressure (Pes) and usage of nasal continuous positive airway pressure (CPAP) as a test may help in the early recognition of these infants, who appear to make more effort to breathe during sleep, based on the indirect evidence of Pes measurements. It is suggested that anatomic features, including a small posterior airway space leading to an abnormal degree of upper airway resistance, may be the cause of the symptoms presented by these infants. Considering the parental anxiety generated by persistence of symptoms after the first year of life in ALTE infants, recognition of this subgroup is important.

Repeated methacholine challenge in normal nonasthmatic subjects (who require higher doses of methacholine than do asthmatic subjects to produce a 20 percent decrease in FEV1) can produce progressively diminishing methacholine responsiveness (or tolerance) with serial challenges. To determine whether tolerance to methacholine occurs in asthmatic subjects as it does in nonasthmatic subjects, we studied eight young (mean age, 24 years) mild asthmatic patients (occasional but not regular use of bronchodilator medications, PC20 methacholine range 0.1 to 7.0 mg/ml) who underwent five sequential methacholine challenges at 1.5-h intervals. Serially increasing concentrations of methacholine were given until FEV1 fell by 20 percent. Results were compared with those in seven nonasthmatic control subjects who underwent an identical protocol. As seen in previous studies, the normal subjects demonstrated significant tolerance to methacholine when each of five challenges was compared to the first. By contrast, in the asthmatic group, the mean cumulative dose of methacholine producing a 20 percent fall in FEV1 in the fifth challenge was not significantly different from the dose required in the first challenge. These results indicate that marked tolerance to methacholine does not occur in mild asthmatic patients with multiple repeated challenges over 6 h. The lower cumulative dose of methacholine required by asthmatic patients may be insufficient to produce tolerance.

Angiography in a 30-year-old man revealed the unique combination of aortic coarctation and an unusual arch anomaly. Proximal to the coarctation, a single arch vessel trifurcated into the brachiocephalic, left common carotid and left subclavian arteries. This anomalous arch vessel is a normal equine variant.

Laryngeal involvement by RA is a common finding, but there have been no studies of laryngeal function in RA patients. This study was undertaken to determine if patients with rheumatoid arthritis have functional abnormalities of the upper airway during phonation which may be the result of synovitis of the laryngeal joints caused by RA. Translaryngeal resistance was measured in six patients with RA and six matched control subjects using an interrupter method to measure PSG and V during vocalization. Patients with RA had a higher R (65.0 +/- 8.15 cm H2O/L/s) than control subjects (38.4 +/- 7.43 cm H2O/L/s [p less than 0.05]). This was the consequence of lower V rates during phonation at similar PSG. We conclude that abnormalities of the larynx in RA patients are common and cause measurable physiologic abnormalities.

Two patients eventually shown to have empyema were encountered in which the initial thoracentesis revealed fluid compatible with either a simple or a complicated parapneumonic effusion. In both cases, the diagnosis of empyema was made by a second thoracentesis done at a close interval of time from a different site. Therefore, the physician should approach parapneumonic effusions systematically, and remember that in some cases, multiple thoracenteses may be required to make the correct diagnosis of an empyema.

We compared bronchopulmonary distribution homogeneity of a radioaerosol before and after hospitalization in 20 patients with cystic fibrosis (CF) with pulmonary exacerbations in order to assess lung improvement. Deposition homogeneity was quantified in terms of skew (an index of distribution symmetry), derived from frequency distribution histograms generated from gamma camera images of the lungs following radioaerosol inhalation. Lower skew values indicate enhanced distribution homogeneity. Right lung skew (RLS) was significantly reduced following therapy (1.00 +/- 0.49 to 0.84 +/- 0.47), whereas skew in the left lung was unchanged (0.95 +/- 0.38 to 0.87 +/- 0.40). The reduction in RLS was significant in patients with Shwachman-Kulczycki (SK) clinical scores less than 50 (1.27 +/- 0.53 to 0.90 +/- 0.42), but not in patients with scores greater than 50 (0.81 +/- 0.38 to 0.80 +/- 0.52). These results indicate that treatment affected the right lung more than the left lung, particularly in patients with SK scores less than 50, and suggests that radioaerosol lung imaging may be valuable in identifying sites of impairment to be targeted during treatment. Statistically, skew was less sensitive an indicator of acute change than several other clinical indices that improved following hospital treatment.

We reviewed the pulmonary history, dyspnea ratings, and pulmonary function test results in 16 patients with L-tryptophan-induced eosinophilia myalgia syndrome to determine the correlation between reported pulmonary complaints and pulmonary function abnormalities. All patients reported pulmonary symptoms. Dyspnea, seen in 14 of 16 (87 percent) patients, was the most common symptom. The severity of dyspnea was graded by the baseline dyspnea index and the oxygen cost diagram. Pulmonary function testing including maximal static inspiratory and expiratory pressures were measured. The DCO was diminished in 12 of 16 (75 percent) patients. The MSIP was decreased in seven out of ten (70 percent) and the MSEP was decreased in nine out of ten (90 percent) of those patients tested. There was a statistically significant correlation between the severity of dyspnea as graded by the BDI and OCD, and the decrease in DCO. These results and a review of the literature of the pulmonary manifestations of EMS lead us to conclude that patients with EMS have a high prevalence of dyspnea, and it appears to be caused by both lung parenchymal involvement, as well as respiratory muscle weakness.

A validation study was performed on the MESAM 4, a digital recording device developed to monitor oxygen saturation, heart rate (HR), snoring, and body position in order to screen subjects for obstructive sleep apnea syndrome (OSAS). MESAM 4 recordings were scored with the computer-based automatic scoring system provided with the equipment. Nocturnal polysomnography (PSG) and MESAM 4 recordings were run simultaneously on 56 subjects presenting with any type of sleep complaint, including those secondary to OSAS. Patients were assigned to one room by hospital administration and were monitored consecutively. The polygraphic equipment and MESAM 4 equipment were placed on the subjects by separate teams. Records of PSG and MESAM 4 were analyzed in double-blind fashion. With the MESAM 4 computerized analysis, three indices based on SaO2 (ODI), on heart rate (HVI), and on snoring (ISI) were obtained, and the number of abnormal respiratory events occurring during the time selected for analysis (TAT) were determined. Polysomnographic records were scored by 30-s epochs following the American Sleep Disorders Association standards for sleep states and stages and for sleep-related events, including sleep apneas, hypopneas, and periodic leg movements. Following independent scoring, 26 subjects were identified with OSAS by PSG, while MESAM 4 identified 25 subjects with OSAS using oxygen algorithm; all had a respiratory disturbance index greater than or equal to 10 with PSG. Results of each polysomnogram and each MESAM 4 analysis were compared. With the polysomnogram used as a standard, the degree of error for each variable with the MESAM 4 was calculated. Specificity and sensitivity of the most accurate index of the MESAM 4, the ODI, were 97 percent and 92 percent, respectively. The other two indices, HVI and ISI, were less accurate: specificity and sensitivity were 32 percent and 58 percent for HVI and 27 percent and 96 percent for ISI. Nevertheless, a combination of all three indices (ODI, HVI, ISI) would have prevented the two false-positive cases we observed. The results of this validation study show that MESAM 4 can be helpful to general practitioners, clinicians, and epidemiologists as a low-cost screening device for subjects with OSAS and habitual snoring.