Drainage routes of bronchial blood flow in anaesthetized sheep.

The systemic circulation to the lung supplies the trachea and airway walls and may be important in the pathophysiology of asthma and pulmonary oedema. An understanding of the venous drainage pathways of this bronchial blood flow may be therapeutically important. The purpose of this study was to understand the normal drainage pathways in sheep. In seven anaesthetized, ventilated sheep we injected echo contrast agents into a systemic vein or into the bronchial artery while performing echocardiography to determine whether the drainage could be observed to the right heart and/or to the left heart. During transoesophageal echo (n=5) or heart surface echo (n=2), cephalic vein injection of <8 microm diameter gelatin microballoons promptly opacified the right but never the left-sided circulation. Air in agitated saline in the seven animals showed the same result. By contrast, injection into the bronchial artery promptly opacified the left atrium, left ventricle, and aorta but not the right-sided circulation in all seven microballoon injections and all but one of the air in agitated saline injections. The failure of the echo agents to pass through the pulmonary circulation may be related to sheep pulmonary intravascular macrophages or the surface forces on air bubbles of small size promoting collapse. The main conclusion is that there are bronchopulmonary anastomoses that connect the bronchial circulation to the pulmonary venous circulation connecting distal to the pulmonary capillaries. Any bronchial venous drainage to the right-sided circulation must have been below the detection level of the instruments and would in any case appear to be much less that the post-pulmonary capillary anastomoses noted. Pulmonary venous hypertension would be expected to have a direct effect on the bronchial circulation.

Does "mainstreaming" guarantee access to care for medicaid recipients with asthma?

OBJECTIVE: Recent reforms in the federal Medicaid program have attempted to integrate beneficiaries into the mainstream by providing them with managed care options. However, the effects of mainstreaming have not been systematically evaluated. DESIGN: Cross-sectional survey. SETTING/PARTICIPANTS: A sample of 478 adult, nonelderly asthmatics followed by a large Northern California medical group. MEASUREMENTS AND MAIN RESULTS: We examined differences in self-reported access by insurance status. Compared to patients with other forms of insurance, patients covered by the state's Medicaid program (Medi-Cal) were more likely to report access problems for asthma-related care, including difficulties in reaching a health care provider by telephone, obtaining a clinic appointment, and obtaining asthma medication. Adjusting for relevant clinical and sociodemographic variables, Medi-Cal patients were more likely to report at least one access problem compared to non-Medi-Cal patients (adjusted odds ratio [AOR], 3.34; 95% confidence interval [CI], 1.43 to 7.80). Patients reporting at least one access problem were also more likely to have made at least one asthma-related emergency department visit within the past year (AOR, 4.84; 95% CI, 2.41 to 9.72). Reported barriers to care did not translate into reduced patient satisfaction. CONCLUSIONS: Within this population of Medicaid patients, the provision of health insurance and care within the mainstream of an integrated health system was no guarantee of equal access as perceived by the patients themselves.

The effects of a managed care educational program on faculty and trainee knowledge, attitudes, and behavioral intentions.

PURPOSE: To assess the state of managed care knowledge and attitudes and to evaluate the effects of a two-day course on participants' knowledge, attitudes, and behavioral intentions. METHOD: In 1996, the University of California, Davis, Medical School invited all medical students, residents, faculty, and administrators to participate in one of two sessions of a two-day course on managed care. Participants in the first session were given both pre- and post-course questionnaires. Participants in the second session were given only post-course questionnaires. The questionnaires measured objective knowledge, attitudes, and behavioral intentions. Participants (other than administrators) who completed the questionnaires also received a follow-up questionnaire six months after the seminar. RESULTS: The two sessions were attended by 818 UC Davis medical students, residents, faculty, and administrators: after excluding 33 non-physician administrators, 428 completed survey packets (55%) were available for full analysis. Before the course, participants in the first session correctly answered on average only 46% of 32 questions about managed care knowledge. Course attendance was associated with significant gains in knowledge (to 67% correct, p < .001) and a marked increase in appreciation for the cost-control effectiveness of managed care (from 3.35 to 3.98 on a five-point scale, p < .001). Knowledge gains were greatest among medical students; changes in attitudes and behavioral intentions were least among residents. Among respondents to a follow-up survey, the changes were partially sustained six months later. CONCLUSION: Within this academic medical center, baseline levels of managed care knowledge were low among faculty as well as among trainees, and attitudes reflected a blend of negativism and wishful thinking. An intensive two-day educational program effectively increased knowledge and changed selected attitudes among critical academic constituencies. Other academic medical centers may wish to consider presenting similar programs in order to orient their faculties and trainees to the economic realities of the foreseeable future.

Attitudes and behavioral intentions regarding managed care: a comparison of academic and community physicians.

Physicians' attitudes toward managed care and the impact of these attitudes on behaviors that affect patient care are important factors in managed care reform. In addition, the attitudes of academic physicians may influence their willingness to reform medical education in an effort to prepare students to practice under managed care. Although it is a conventional opinion that the academic health center and its academic physicians are antagonistic toward managed care, there has not been a direct comparison of the attitudes of these physicians to those of practicing community physicians. We used a self-administered questionnaire to assess attitudes toward managed care and behavioral intentions regarding practices related to managed care; a sample of academic physicians (n = 129) was compared with a sample of community physicians (n = 307). Community physicians were less negative in their evaluations of the quality of care in a managed care environment, but no differences were identified between the two groups with regard to the cost-effectiveness, inevitability, or need to adapt to managed care. Academic specialists were more likely than academic primary care physicians to rate managed care as something to which they needed to adapt. Community physicians were less likely to report a willingness to change their referral patterns. Aggregating across practice type, we also uncovered systematic differences between primary care and specialist physicians. The data suggest that opinions about quality and cost-containment in managed care are significant correlates of intentions to change practice behaviors.

Physicians' attitudes toward managed care: assessment and potential effects on practice behaviors.

This study was designed to identify the key components of physicians' attitudes toward managed care and develop a tool to assess these components. We developed a questionnaire based on physicians' reactions to managed care, as reflected in the published literature. We mailed this questionnaire to a sample of 753 community physicians in the greater Sacramento area. A factor analysis of these data (n = 315) identified five unifactorial scales, which we labeled managed care quality, need to adapt to managed care, cost-containment effectiveness of managed care, personal knowledge of managed care, and inevitability of managed care. Physicians were most negative about the quality of managed care and most in agreement about the need to adapt to it. Correlations among these five scales, while statistically significant, were modest in size, suggesting that these physicians were quite discriminating in their evaluations. In comparison with medical/surgical specialists, primary care physicians rated the quality of managed care, their knowledge of it, and the inevitability of a national transition to managed care more positively. These measures predicted the physicians' intentions to alter their medical behaviors to comply with managed care practices.

Optimal pharmacologic treatment of the critically ill patient with obstructive airways disease.

There are few experimental data evaluating the effect of inhaled bronchodilator treatment in the critically ill patient in the intensive care unit. Extrapolating from the data that are available in chronic and acute asthma and chronic obstructive pulmonary disease (COPD) studies, it appears that both agents may be beneficial. Beta-adrenergic receptor agonists are first-line agents in asthma. However, anticholinergics may be valuable as additive agents or as single agents if the patient is intolerant of beta-adrenergic side effects. This may be especially important in the critically ill patient with multiple organ failure in whom excessive tachycardia may reduce oxygen delivery. Anticholinergics and beta 2-adrenergic agonists both appear to be beneficial in smoking-related chronic bronchitis. Finally, because of the severity of illness in the critical care setting, both drugs should be titrated to maximal effect when possible, monitoring closely for adverse effects of the larger than normal doses that are used.

Treatment of bronchogenic carcinoma.

Progress in the treatment of bronchogenic carcinoma, the leading cause of cancer death in men and women in the United States, has been slow throughout the past few years, and no major breakthroughs have occurred in the past 12 months. Significant developments in monoclonal antibody techniques and tissue cellular markers offer hope for improved diagnosis and are useful in staging and following disease response to treatment. Advances in patient selection and staging have been primarily responsible for improved surgical outcomes, but some new surgical alternatives like video-assisted thoracoscopy and other tissue-sparing procedures may offer reasonable outcomes with a lower morbidity. New drugs and new drug combinations are being evaluated with hematopoietic growth factors in the management of small cell lung cancer. Neoadjuvant chemotherapy and radiotherapy are finding a definite role in the management of non-small cell lung cancer. The optimal parameters for radiotherapy in the management of small cell lung cancer are being defined. The use of immunotoxins, adjuvant immunotherapy, and monoclonal antibodies offers major theoretical promise, but are as yet in the early stages of development. Ancillary techniques for palliation of local airway obstruction, including both laser and endobronchial stents, are proving beneficial in selected patients.

Risk factors for adverse outcome in persons with pneumococcal pneumonia.

OBJECTIVE: To identify risk factors for death and respiratory failure in persons with penicillin-sensitive pneumococcal bacteremia and pneumonia from data available at initial clinical evaluation. DESIGN: Retrospective chart review of persons with pneumococcal bacteremia and pneumonia. SETTING: Tertiary care medical center (University of California Davis Medical Center, Sacramento). PATIENTS: One hundred two consecutive adults admitted to the hospital for treatment of pneumococcal pneumonia with bacteremia. RESULTS: Of 102 persons, 25 (25%; 95% confidence interval [CI], 17 to 34%) died and 17 (16%; 95% CI, 10 to 25%) survived mechanical ventilation for respiratory failure. In univariate analyses, persons with preexisting lung disease (relative risk [RR], 2.0; 95% CI, 1.3 to 3.1), initial body temperature < 38 degrees C (RR, 2.1; 95% CI, 1.3 to 3.6), or nosocomial infections (RR, 2.5; 95% CI, 1.8 to 3.6) or who were > or = 48 years old (RR, 2.7; 95% CI, 1.5 to 4.8) were at greater risk for adverse outcomes than persons without these risk factors. Of 25 persons without these risk factors, only one (4%; 95% CI, 0 to 20%) died, and the remaining 24 persons did not require intensive care. Using these risk factors in a multivariate logistic model, death or respiratory failure would have been predicted in 67% of persons and better outcome predicted in 83% of the persons. In multivariate analysis, nosocomial infection was the greatest risk factor (adjusted odds ratio, 17.3; 95% CI, 3.1 to 98). CONCLUSIONS: Risk factors identified at hospital admission can predict the outcome in persons with pneumococcal pneumonia and bacteremia. Identifying these factors may allow earlier use of intensive care or more aggressive treatment. Independent of age, nosocomially acquired infections were the greatest risk factor for death or respiratory failure.

Survival of patients undergoing Nd:YAG laser therapy compared with Nd:YAG laser therapy and brachytherapy for malignant airway disease.

Brachytherapy in combination with Nd:YAG laser therapy may add to the duration of survival of the palliative period when compared with laser alone. A retrospective study of patients with inoperable squamous cell carcinoma (SCC) was undertaken to determine if there was a difference in survival between those patients treated with Nd:YAG laser alone and those treated with Nd:YAG laser and brachytherapy. Twenty-two patients were treated with brachytherapy for malignant airway disease at our institution of which 13 had SCC. All patients had previously received treatment with Nd:YAG laser for exophytic disease. Survival was compared with those patients treated with Nd:YAG laser alone for SCC involving the airway. There was no statistical difference between the two groups with regard to age. The duration of survival of patients with SCC of the airway from the first Nd:YAG laser treatment was determined. A significant difference between those patients treated with Nd:YAG laser alone and those patients treated with combined therapy was found (p < 0.001). Brachytherapy may potentiate the duration of survival in patients with SCC involving the airway compared to palliation with Nd:YAG laser alone.

Time course of ozone-induced neutrophilia in normal humans.

Five normal human subjects were exposed for 1 h to filtered air (FA) once and to 0.3 ppm O3 on 3 separate days. Bronchoalveolar lavage (BAL) fluid was obtained less than 1 h after FA and either less than 1, 6, or 24 h after O3 exposure. FEV1 was measured before the exposures and the BAL. The first aliquot [proximal airway (PA) sample] was analyzed separately from the pooled Aliquots 2 through 4 [distal airway and alveolar surface (DAAS) sample]. The data from the PA and DAAS samples were then combined to calculate the values that would have been obtained by pooling all BAL washes. FEV1 was significantly (p less than 0.05) decreased 1 h after O3 exposure, but it returned to preexposure values at 6 and 24 h after O3. The percent of neutrophils in the PA sample was significantly elevated at less than 1 h (3.7%) at 6 h (16.5%), and at 24 h (9.2%) after O3. The percent of neutrophils in the DAAS sample and calculated pooled values were significantly elevated at 6 h (4.1 and 7.6%) and at 24 h (5.1 and 5.8%) after O3. These data demonstrate that O3-induced symptoms, FEV1 decrements, and airway neutrophilia follow different time courses and indicate that the pooling of BAL washes may obscure the detection of an O3-induced bronchiolitis. The degree of neutrophilia in the BAL did not correlate with the sensitivity of the individual subjects when measured by acute changes in FEV1, suggesting a dichotomy of pathways that result in O3-induced airway neutrophilia and pulmonary function decrements.

Closure of a bronchopleural fistula with bronchoscopic instillation of tetracycline.

Persistent bronchopleural fistulas (BPF) due to infection, trauma, or thoracic surgical procedures are often difficult to manage. We report a patient with fulminant Staphylococcus aureus pneumonia complicated by chronic BPF formation which prevented weaning from mechanical ventilation due to severe air leak. Fistula closure was obtained by instillation of tetracycline into the fistula via a fiberoptic bronchoscope using a balloon catheter and blood clot occlusion technique. This closed the BPF and allowed successful weaning from mechanical ventilation.

Nd:YAG laser bronchoscopy. Rigid or fiberoptic mode?

One hundred twenty four Nd:YAG laser procedures were performed on 79 patients (age range, 25 to 89 years) over a five-year period at our institution. Over 90 percent of patients had malignant tumors. The fiberoptic bronchoscope (FOB group) was used exclusively during the first two years (61 cases, 32 patients). All except four of these cases utilized conscious sedation and local anesthesia. Subsequent to this, the rigid bronchoscope (RB group) was used as the primary instrument under general anesthesia (51 cases, 42 patients). Twelve cases combined both bronchoscopic modalities (combined group, 12 patients). The percentage improvement in proximal airway lumen diameter post-Nd:YAG laser therapy was significantly greater using the RB (p less than 0.05). For distal lesions, the FOB was superior (p less than 0.05). There was no difference in the complication or survival rates between the groups. Our data suggest that whenever possible, the RB should be used to treat proximal lesions, and the FOB should be used for distal lesions. Both bronchoscopes are often used together. Hence, laser bronchoscopists should be proficient in both bronchoscopic techniques.

Using pulmonary function testing in the diagnosis and treatment of asthma.

Asthmatics have remarkable changes in their pulmonary function in response to numerous external stimuli and internal controls. Serial pulmonary function testing in the office, hospital, at home, or the work place allows the objective measurement that is necessary to intelligently diagnose and treat these patients. Once the patient and the physician understand how to use the techniques for monitoring the degree of airways obstruction, they become a key in medical management decisions.

Acute ozone exposure increases plasma prostaglandin F2 alpha in ozone-sensitive human subjects.

Twenty O3-sensitive and 2O O3-nonsensitive subjects participated in a study to investigate the effects of disparate O3 sensitivity on plasma prostaglandin F2 alpha) responses consequent to exposure to ambient O3 concentrations. Subjects were selected from a pool of 75 normal healthy college-aged males who had been previously exposed to 0.35 ppm O3 for 1 h at an exercising VE of 60 L/min. The selection criterion used was the observed decrement in FEV1 after the O3 exposure: O3-sensitive, FEV1 decrement greater than 24%; O3-nonsensitive, FEV1 decrement less than 11%. Each subject was exposed to filtered air and to 0.20 and 0.35 ppm O3 for 80 min while exercising at a VE of 50 L/min. These experimental protocols were divided into two 40-min sessions separated by a period of 4 to 10 min. PGF2 alpha, FVC, FEV1, and FEF25-75 were evaluated before, during, and after each protocol. SGaw and Vtg were measured before and after each protocol. Plasma PGF2 alpha was significantly increased in the O3-sensitive group during and after the 0.35-ppm O3 exposure.

Indomethacin pretreatment reduces ozone-induced pulmonary function decrements in human subjects.

We studied whether O3-induced pulmonary function decrements could be inhibited by the prostaglandin synthetase inhibitor, indomethacin, in healthy human subjects. Fourteen college-age males completed six 1-h exposure protocols consisting of no drug, placebo, and indomethacin (Indocin SR 75 mg every 12 h for 5 days) pretreatments, with filtered air and O3 (0.35 ppm) exposures within each pretreatment. Pretreatments were delivered weekly in random order in a double-blind fashion. Ozone and filtered air exposures, separated by 72 h, were delivered in random order in a single-blind fashion. Exposures consisted of 1-h exercise on a bicycle ergometer with work loads set to elicit a mean minute ventilation of 60 L/min. Statistical analysis revealed significant (p less than 0.05) across pretreatment effects for FVC and FEV1, with no drug versus indomethacin and placebo versus indomethacin comparisons being significant. These findings suggest that cyclooxygenase products of arachidonic acid, which are sensitive to indomethacin inhibition, play a prominent role in the development of pulmonary function decrements consequent to acute O3 exposure.

Isoniazid overdose: pharmacokinetics and effects of oral charcoal in treatment.

The pharmacokinetics of isoniazid following overdose in two patients is described. One patient was treated with haemodialysis for seizures and persistent coma without obvious immediate clinical improvement. In addition, three volunteer subjects were given isoniazid orally on two separate occasions. Isoniazid elimination pharmacokinetics were determined with and without concominant charcoal. Oral activated charcoal totally prevented the absorption of isoniazid. Current recommendations for treatment of isoniazid overdoses include intravenous pyridoxine (one gram IV pyridoxine for each gram of ingested isoniazid), intravenous diazepam or phenobarbital for continued seizures, and gastric decontamination with lavage and activated charcoal (1 g/kg). Extraordinary measures such as early haemodialysis and haemoperfusion should be reserved for those patients with persistent coma or refractory seizures.

Emergency airway clot removal in acute hemorrhagic respiratory failure.

Three cases of respiratory failure and severe hypoxemia caused by blood clot obscuring the central airway are described. A technique to clear the airway using a no. 6 Fogarty balloon-tip embolectomy catheter inserted through a flexible fiberoptic bronchoscope was used in all three cases. Marked improvement and stabilization occurred while definitive therapy was undertaken.

Pericarditis caused by beta-lactamase-producing Haemophilus influenzae: report of two cases in adults and review of the literature.

Two adult patients with pericarditis caused by beta-lactamase producing Haemophilus influenzae are reported and their management reviewed. Both had pharyngitis, epiglottitis, pneumonia, empyema, or septicemia and were cured with antimicrobics and pericardial drainage (one by catheter and one by surgery). Eleven previously reported cases of pericarditis caused by Haemophilus influenzae are also reviewed. In reviewing this rare cause of bacteria pericarditis, it is important to recognize the antibiotic resistance profile, the incidence of pericardial tamponade, and the use of surgical drainage. Antibiotic selection for this organism is also discussed, as well as the importance of biotyping.

Noninvasive lung water quantitation by 1H nuclear magnetic resonance spectroscopy.

Three models of volume-dependent pulmonary edema were used in rabbits. Changes in lung water were measured by proton (1H) nuclear magnetic resonance spectroscopy (NMR) using a surface coil system, topical magnetic resonance. The anesthetized rabbits were ventilated with high frequency jet ventilation to minimize lung motion, and the surface coil was placed on the rabbit chest wall over the right lung. The rabbit preparation was placed in an Oxford Research Systems TMR-32 20-cm bore magnet. There was a close correlation (r greater than or equal to 0.90) between the gravimetrically determined lung wet to dry weight ratios and the percent change in the spectral areas as measured with 1H NMR, in all 3 experimental models.