Home mechanical ventilation.

Recently, interest in the use of mechanical ventilation outside the hospital setting has been increasing. Patients with various types of chronic respiratory failure may benefit from this approach. Evaluation for long-term mechanical ventilation necessitates assessment of the underlying disease process, the goals of the medical team, and the needs of the patient and family. Externally applied negative-pressure devices can provide adequate ventilation for many patients, particularly those with neuromuscular diseases. Positive-pressure ventilation by means of a tracheostomy provides greater control of the airway, allows adjustment of tidal volume and minute ventilation, and may be delivered by portable equipment. Ongoing care and support services in the home must be provided. A variety of mechanical devices and new techniques of ventilator support have made home mechanical ventilation a realistic option for long-term care.

Nocturnal nasal ventilation for treatment of patients with hypercapnic respiratory failure.

We reviewed the Mayo Clinic experience with nocturnal nasal ventilation (NNV) and retrospectively assessed the clinical benefits, patient compliance, and complications. NNV had been instituted in 26 patients with daytime hypercapnia and nocturnal hypoventilation due to neuromuscular diseases or chronic obstructive pulmonary disease. After initiation of NNV, 21 of 26 patients continued to use this treatment regularly (81% compliance rate) and considered their life-style improved. In this subset of patients, the arterial partial pressure of carbon dioxide during unassisted breathing decreased from 64 +/- 13 to 51 +/- 7 mm Hg, and the arterial partial pressure of oxygen increased from 58 +/- 12 to 68 +/- 8 mm Hg. No significant change was noted in the forced vital capacity or maximal respiratory pressures. Four of the five patients in whom NNV had been discontinued cited discomfort related to the mask or severity and poor prognosis of the underlying illness as reasons for cessation of treatment. We conclude that NNV is well tolerated by most patients and may improve alveolar ventilation and arterial oxygenation in patients with chronic respiratory failure.

Exercise limitation and pulmonary rehabilitation in chronic obstructive pulmonary disease.

Impairment of exercise tolerance is a common problem in patients with severe chronic obstructive pulmonary disease. The cause of exercise intolerance in patients with severe chronic obstructive pulmonary disease is multifactorial and includes impaired lung mechanics, fatigue of inspiratory muscles, impaired gas exchange, right ventricular dysfunction, malnutrition, occult cardiac disease, deconditioning, and psychologic problems; however, impaired lung mechanics and gas exchange abnormalities seem to be the major limiting factors. Recently, the approach to management of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease has changed because improvement in exercise tolerance has been demonstrated after pulmonary rehabilitation. Other adjunctive measures that have been shown to contribute to the observed improvement in exercise tolerance include administration of oxygen, nutritional support, cessation of smoking, and psychosocial support. The roles of ventilatory muscle endurance training, respiratory muscle rest therapy, nasally administered continuous positive airway pressure, and training of the muscles of the upper extremities are less clearly defined.

Outcomes of patients admitted to a chronic ventilator-dependent unit in an acute-care hospital.

The outcomes in 61 patients admitted to a chronic ventilator-dependent unit (CVDU) at Saint Marys Hospital in Rochester, Minnesota, during an 18-month period are summarized. This unit was designed for patients who could not be weaned from mechanical ventilators after repeated attempts. Most patients had been ventilator dependent for more than 21 days, but some patients were admitted to the CVDU after briefer periods if special circumstances suggested that weaning from mechanical ventilation would be difficult. The unit was organized to provide a multidisciplinary approach to the general medical and respiratory management of these patients, including a physiologic evaluation of the respiratory system to determine the actual cause of ventilator dependence and complete medical, nursing, and psychosocial assessments to help adopt a plan of care and weaning from the ventilator. Of the numerous causes for ventilator dependence in this study group, chronic obstructive pulmonary disease was the most frequent underlying diagnosis. Of the 61 patients admitted to the CVDU, 58 survived, and 53 were liberated from the mechanical ventilator. Ultimately, 35 patients were dismissed directly home from the CVDU. Five of these patients required nocturnal mechanical ventilation. An additional eight patients were dismissed home after rehabilitation. After being weaned from mechanical ventilation, 11 patients were eventually transferred to nursing homes, and 3 additional patients were transferred to a local hospital or physical medicine unit. One patient remains in the CVDU. Thus, the CVDU has successfully liberated patients from ventilator dependence. In addition, because of a decreased need for nursing care, the unit has been cost-effective.

An integrated approach to evaluation of the solitary pulmonary nodule.

In this article, we describe an integrated approach for detection and evaluation of solitary pulmonary nodules. Initial evaluation of the solitary pulmonary nodule includes tomography, fluoroscopy, and comparison with previously obtained roentgenograms. Subsequently, thin-section computed tomography and phantom densitometry can be used for analysis, if indicated. The rationale for the use of computed tomography in the radiologic staging of bronchogenic carcinoma is to expedite and assist in the identification of the subset of patients with resectable tumors. For nonsurgical tissue diagnosis, fiberoptic bronchoscopy is generally the initial procedure for lesions 2.0 cm or larger in diameter, and transthoracic needle biopsy is used for those smaller than 2.0 cm.

Massive pulmonary hemorrhage complicating mitral prosthetic valve obstruction.

A case is reported of prosthetic mitral valve obstruction in a patient who had had three hospital admissions with massive hemoptysis. A diagnosis was finally made after two-dimensional echocardiography with Doppler and cardiac catheterization were performed. The patient was successfully treated with re-replacement of the valve. Any new pulmonary or cardiac symptom in a patient with a prosthetic valve requires prompt evaluation and treatment.

Outcome of patients cared for in a ventilator-dependent unit in a general hospital.

We describe our initial experience with the admission of 129 patients for 132 episodes of ventilator-dependence to a self-contained ventilator-dependent unit (VDU) in a general hospital and present a survival comparison between VDU patients and a historic control population from the same institution. Forty-three patients were screened and denied admission to the VDU because long-term ventilator dependence was not felt to be a probable outcome (56%); they were medically unstable, often requiring electrocardiographic monitoring (19%), they had poor rehabilitation potential because of markedly depressed mental status (13%), or they preferred to be treated closer to their homes (12%). Thirteen (9.8%) of the VDU patients died in the hospital compared to 44 (42%) in the historic control group. After exclusion of patients with multiorgan failure (who made up 26% of the control group) and using a proportional hazard model to adjust for group differences in age and disease class, the difference in hospital mortality remained highly significant (p < or = 0.01). Ninety-one of the 119 VDU patients (77%) were ultimately able to return home; 16 (13%) continued to use a ventilator intermittently at night; 26 patients (22%) were permanently placed in nursing homes, all off of the ventilator. Overall, 88% of the 119 patients discharged had been liberated from mechanical ventilation. Ninety-seven (82%) and 86 (72%) remain alive 1 and 2 years after discharge, respectively. Some of the survival benefits may be directly attributed to the VDU. Others reflect a change in treatment philosophy, which was nevertheless reinforced by our VDU experience.

Evaluation and management of solitary and multiple pulmonary nodules.

The evaluation and management of a patient with an SPN is guided by principles that were derived from earlier surgical studies. Stability or no growth for at least 2 years, the presence of calcium in characteristic patterns, and age less than 35 years without any associated risk factors are reliable indicators of a benign process. Fluoroscopy and localized tomography are helpful in evaluation of an SPN. If the nodule is still considered indeterminate, CT scanning, with the use of thin section cuts through the nodule, is now widely employed. If calcium is present in a characteristic pattern, the nodule is considered benign. If the nodule is very dense or more dense than a phantom reference nodule, the nodule has a high likelihood of being benign. Nodules that are less dense than the phantom nodule are indeterminate, and approximately 25% of these nodules will be benign. Computed tomography scan of the chest and upper abdomen is indicated in patients with a previous history of malignancy or when there is a high suspicion that the nodule is malignant. The further evaluation and management of SPNs that are indeterminate after CT examination are controversial. Some recommend tissue biopsy via transbronchoscopic or transthoracic approach, whereas others recommend immediate thoracotomy. Observation is indicated in certain situations when the chance of malignancy is quite low, the patient is not an operable candidate, or when the patient refuses further invasive evaluation. The physician's role in the management of a patient with an SPN is to educate and advise. The physician must be aware of the patient's anxieties, fears, and attitude and provide an opportunity for active participation by the patient in the decision-making process. Multiple pulmonary nodules are most commonly encountered in patients with metastatic disease to the lungs. Other less commonly encountered diseases that present as multiple pulmonary nodules include infections, arteriovenous malformations, Wegener's granulomatosis, and lymphoma. The evaluation and management of the patient with multiple pulmonary nodules are usually guided by the history, physical examination, and laboratory findings.

Fulminant brain necrosis from atrial myxoma showers.

BACKGROUND: Atrial myxoma is uncommon and may be associated with brief isolated ischemic events. We describe a patient with atrial myxoma and an incompletely evaluated ischemic stroke followed 1 year later with almost complete brain necrosis. SUMMARY OF REPORT: A 63-year-old woman presented with a rapidly progressive illness resulting in coma within 24 hours from multiple myxomatous emboli. Cranial computed tomographic scan demonstrated multiple hypodensities in both cerebellar and cerebral hemispheres. Postmortem examination revealed virtually complete brain necrosis, multiple peripheral artery embolizations, embolization in the coronary arteries with acute myocardial infarction, and tumor emboli in the spleen and kidneys. CONCLUSIONS: Although uncommon, atrial myxoma may present as a fatal multiple organ embolization that includes both anterior and posterior circulation territories of the brain.

Interstitial lung disease in polymyositis and dermatomyositis. Clinical features and prognosis as correlated with histologic findings.

Open lung biopsies from 14 patients and autopsy tissue from one patient with polymyositis/dermatomyositis were reviewed in an attempt to correlate histologic features with clinical, radiographic, and prognostic variables. Three major groups based on histologic patterns were identified: bronchiolitis obliterans organizing pneumonia (BOOP), usual interstitial pneumonia (UIP), and diffuse alveolar damage (DAD). Patients with BOOP had a more favorable prognosis than did patients with UIP. Patients with DAD had a uniformly poor prognosis. One patient had a cellular interstitial pneumonia and did well. Histologic subclassification of the interstitial lung disease proved to be a better predictor of survival than did the radiographic appearance or the clinical presentation. These findings suggest that there is a broader range of histologic findings in polymyositis-dermatomyositis than is suggested in the literature and subclassification may be useful for prognosis.

Lung nodules: dual-kilovolt peak analysis with CT--multicenter study.

PURPOSE: To test the following hypothesis: The greater the increase in the mean computed tomographic (CT) number of a radiologically indeterminate lung nodule from the CT number on a 140-kVp CT image to that on an 80-kVp CT image, the more likely the nodule is benign (ie, contains calcium). MATERIALS AND METHODS: Two hundred forty indeterminate lung nodules were prospectively studied at four institutions: Mayo Clinic Scottsdale, Ariz (n = 160); Mayo Clinic Rochester, Minn (n = 50); Shiga Health Insurance Hospital, Otsu, Japan (n = 25); and Duke University Medical Center, Durham, NC (n = 5). Of the 240 nodules, 157 met the entrance criteria for this study and had a diagnosis. All nodules included were solid, 5-40-mm diameter, relatively spherical, homogeneous, and without visible evidence of calcification or fat. Each nodule was evaluated by using 3-mm-collimation, nonenhanced CT scans with both 140- and 80-kVp x-ray beams. RESULTS: There were 86 (55%) benign and 71 (45%) malignant nodules. The median increase in the nodule mean CT number from the CT number on 140-kVp images to that on 80-kVp images was 2 HU for benign nodules and 3 HU for malignant nodules. This difference was not statistically significant. The area under the receiver operating characteristic curve was 0.505. CONCLUSION: Dual-kilovolt peak analysis with current CT technology does not appear to be helpful in the identification of benign lung nodules.

Lung nodule enhancement at CT: multicenter study.

PURPOSE: To test the hypothesis that absence of statistically significant lung nodule enhancement (< or =15 HU) at computed tomography (CT) is strongly predictive of benignity. MATERIALS AND METHODS: Five hundred fifty lung nodules were studied. Of these, 356 met all entrance criteria and had a diagnosis. On nonenhanced, thin-section CT scans, the nodules were solid, 5-40 mm in diameter, relatively spherical, homogeneous, and without calcification or fat. All patients were examined with 3-mm-collimation CT before and after intravenous injection of contrast material. CT scans through the nodule were obtained at 1, 2, 3, and 4 minutes after the onset of injection. Peak net nodule enhancement and time-attenuation curves were analyzed. Seven centers participated. RESULTS: The prevalence of malignancy was 48% (171 of 356 nodules). Malignant neoplasms enhanced (median, 38.1 HU; range, 14.0-165.3 HU) significantly more than granulomas and benign neoplasms (median, 10.0 HU; range, -20.0 to 96.0 HU; P < .001). With 15 HU as the threshold, the sensitivity was 98% (167 of 171 malignant nodules), the specificity was 58% (107 of 185 benign nodules), and the accuracy was 77% (274 of 356 nodules). CONCLUSION: Absence of significant lung nodule enhancement (< or = 15 HU) at CT is strongly predictive of benignity.