Right atrial myxoma with right to left shunting and mitral valve prolapse.

A 58 year old black man presented with progressive dyspnea and persistent systemic arterial hypoxemia. Initial hemodynamic evaluation revealed mitral valve prolapse and evidence for isolated right to left shunting, presumed to be extracardiac. A detailed pulmonary evaluation disclosed normal volume and flow parameters with a mild reduction of the single breath carbon monoxide diffusing capacity. An open lung biopsy disclosed no abnormalities. Radionuclide studies of the heart, however, suggested the possibility of a filling defect in the right atrium, and echocardiography enforced the impression of a mass in the right atrium, subsequently demonstrated by superior vena cava angiography. Our report outlines the use of multiple diagnostic tools in difficult situations and stresses the importance of right atrial myxoma in the differential diagnosis of isolated right to left shunting

Tuberculosis in the world today.

Tuberculosis remains a major public health problem throughout the world. Although the disease was previously well controlled in the United States, several factors now present a potential for the reemergence of tuberculosis as a significant public health concern. Physicians who will be responsible for the care of these patients must be trained to respond appropriately.

Mechanical ventilation for respiratory failure in myasthenia gravis. Two-year experience with 22 patients.

We evaluated a 2-year experience involving 22 patients who required prolonged mechanical ventilation for respiratory failure associated with myasthenia gravis. The most frequent cause of respiratory failure was operation, and the most common type of procedure was thymectomy. Next in frequency as exacerbating factors were myasthenic crisis and cholinergic crisis. Of the 22 patients, 21 survived and were weaned from the ventilator after 1 to 32 days of respiratory support.

The chronic ventilator-dependent unit: a lower-cost alternative to intensive care.

OBJECTIVE: To evaluate the fixed costs and patient outcomes of a specialty hospital unit for medically stable ventilator-dependent patients. The chronic ventilator-dependent unit (CVDU) was established to facilitate early dismissal from costly intensive care unit (ICU) hospitalization for patients requiring continued specialized care. PATIENTS AND METHODS: We carried out a cost analysis of the various ICUs that transferred patients to the CVDU by year from 1993 through 1998. In addition, direct and indirect costs for the CVDU were established by year for the same period. We then calculated the cost effect of transferring these patients for care from each high-cost ICU to the lower-cost CVDU. Ventilator weaning and mortality rates were also determined. RESULTS: During the 6 years of this study, $4,832,551 in patient care costs were saved by transferring care for 964 patients from ICUs to the CVDU. Ventilator weaning was successful in 64% of 549 patients, and mortality was 7% in the same patient group. CONCLUSIONS: Care in the CVDU yielded lower fixed costs per patient-day, and CVDU care was comparable to ICU hospitalization.

Benign lymphocytic angiitis and granulomatosis: experience with three cases.

Of three patients with lung-biopsy-proven benign lymphocytic angiitis and granulomatosis, two experienced complete resolution of their disease from therapy with chlorambucil and one underwent spontaneous remission with no drug therapy after lung biopsy and removal of a benign spindle cell thymoma. Clinically, it is difficult to determine whether benign lymphocytic angiitis is a low-grade (prelymphomatous) lymphoma or a vasculitis. Its position in this spectrum of diseases is uncertain. Nonetheless, benign lymphocytic angiitis and granulomatosis corresponding to a low-grade angiocentric immunoproliferative lesion is a clinicopathologically useful concept.

The Mayo Ventilator-Dependent Rehabilitation Unit: a 5-year experience.

OBJECTIVE: To describe the outcomes of 206 patients admitted to the Mayo Ventilator-Dependent Rehabilitation Unit (VDRU) during a 5-year study period. DESIGN: We analyze the patient data for 1990 through 1994, which had been prospectively entered into a computer database for a cohort of 206 patients who had become ventilator dependent during their current hospitalization. MATERIAL AND METHODS: Patients in the VDRU were classified into one of six categories that reflected the reasons for ventilator dependence. Ability to be weaned from mechanical ventilation, duration of hospital stay and ventilator dependence, outcome, disposition, demographics, and long-term survival were analyzed. The VDRU patient group was compared for hospital and follow-up outcomes with a group of historical control patients previously described by us. RESULTS: The Mayo VDRU was established in January 1990. During the first 5 years of its operation, 206 newly ventilator-dependent patients were admitted to the VDRU, 190 (92%) of whom survived to be dismissed; 16 patients (8%) died in the hospital. Of the 190 patients dismissed, 77% were able to return to their homes. Overall, 153 patients were liberated from mechanical ventilation, whereas 37 remained either completely or partially ventilator dependent. Of these 37 patients, 27 (73%) were receiving nocturnal mechanical ventilation only. The 4-year survival was 53%. CONCLUSION: The Mayo VDRU has been highly successful in liberating newly ventilator-dependent patients from mechanical ventilation. The long-term survival after management in the VDRU has been excellent. In addition, the medical charges for care in the VDRU are less than intensive-care unit charges.

Electrophrenic respiration: report of six cases.

The development of electrophrenic respiration has permitted freedom from mechanical ventilation for patients who have irreversible respiratory failure in association with high-cervical spinal cord or brainstem lesions. There are three basic criteria for successful diaphragm pacing: (1) the need for long-term mechanical ventilatory assistance, (2) a functionally intact phrenic nerve-diaphragm axis, and (3) chest wall stability. Inability to achieve satisfactory pacing can be due to malfunction of equipment, instability of the chest wall, or inadequate neuromuscular responsiveness. These features of diaphragm pacing are exemplified in a series of six patients. Three achieved independence from mechanical ventilatory assistance with full-time phrenic pacing. In one patient, only limited electrophrenic respiration was achieved, and in another the method was entirely unsuccessful. Although functioning well, pacing systems were removed from the sixth patient because of infection. Diaphragm pacing can be a valuable form of respiratory support for carefully selected patients.

The clinical spectrum of critical illness polyneuropathy.

OBJECTIVE: To describe the entity of critical illness polyneuropathy and review our experience with six cases. DESIGN: We present case reports of six patients with polyneuropathy associated with critical illness, who received medical care at the Mayo Clinic between 1992 and 1994, and discuss similar cases from the literature. RESULTS: Critical illness may damage peripheral nerves. In previous studies, sepsis and multiorgan failure have been found to trigger a peripheral neuropathy. Of our six patients with critical illness polyneuropathy, all had a preceding severe bacterial infection or septic shock. In one patient who had long-term administration of vecuronium bromide and had received massive intravenous doses of corticosteroids, sural nerve and quadriceps muscle biopsy specimens were available; they revealed axonal neuropathy and notable myopathic changes, respectively. The outcome was good in patients who survived the critical illness. CONCLUSION: Polyneuropathy in critically ill patients may be a cause of severe generalized limb weakness and occurs in the setting of a sepsis syndrome. The long-term outcome is good in patients who recover from the underlying critical illness. Compression neuropathies may be a cause of permanent sequelae.

Differential mechanical ventilation in respiratory failure due to severe unilateral lung disease.

Severe unilateral lung disease that produces respiratory failure may necessitate mechanical ventilatory support to sustain gas exchange. This article describes the successful use of differential lung ventilation in the management of one patient with diffuse unilateral pneumonia and another with a postoperative bronchopleural fistula after standard methods of mechanical ventilation failed to provide adequate gas exchange for these patients.

Respiratory failure in Guillain-Barré syndrome: a 6-year experience.

Seventy-nine patients with acute Guillain-Barré syndrome were seen during a 6-year period. Twenty-one were admitted to a respiratory intensive care unit, where they remained for 58 +/- 26 days (range 14 to 105 days). Thirteen patients required nasotracheal intubation followed by tracheostomy and mechanical ventilation. The tracheostomy tube was in place for an average of 50 +/- 27 days (range 10 to 104 days). Four patients had complications of tracheostomy; two of these were significant, and one of them led directly to the patient's death. There were no complications due to mechanical ventilation, from which 11 patients were successfully weaned after a mean period of 37 +/- 29 days (range 7 to 93 days). Three of the 79 patients (3.8%) died of complications of their disease or its treatment. Respiratory failure in this condition is protracted and its complications are mainly those of prolonged endotracheal intubation with a tracheostomy tube.

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.

Assessment of prediction of mortality by using the APACHE II scoring system in intensive-care units;.

Some investigators have suggested that information on quality of care in intensive-care units (ICUs) may be inferred from mortality rates. Specifically, the ratio of actual to predicted hospital mortality (A/P) has been proposed as a valid measure for comparing ICU outcomes when predicted mortality has been derived from data collected during the first 24 hours of ICU therapy with use of a severity scoring tool, APACHE II (acute physiology and chronic health evaluation). We present a comparison of mortality ratios (A/P) in four ICUs under common management, in two hospitals within a single institution. Significant differences in A/P were detected for nonoperative patients (0.99 versus 0.67;P = 0.014) between the two hospitals. This variation was traced to uneven representation of a subset of patients who had chronic health problems related to diseases that necessitated admission to the hematology-oncology or hepatology service. No differences in A/P were seen between the two hospitals for operative patients or for nonoperative patients on services other than hematology-oncology or hepatology. Thus, differences in A/P detected by using the APACHE II system not only may reside in operational factors within the ICU organization but also may be related to weaknesses in the APACHE II model to measure factors intrinsic to the disease process in some patients. We suggest that case-mix must be examined in detail before concluding that differences in A/P are caused by differences in quality of care.

Respiratory failure in Lambert-Eaton myasthenic syndrome.

Five patients with the Lambert-Eaton myasthenic syndrome who required more than 48 hours of mechanical ventilation for respiratory failure are described. All five had small cell bronchogenic carcinoma. In one patient with associated chronic bronchitis, one with interstitial pulmonary fibrosis, and one other, respiratory failure requiring mechanical ventilation developed as a result of the Lambert-Eaton myasthenic syndrome. The two other patients had received muscle relaxant drugs, but the acute respiratory failure episode in one of the two was not clearly related to their administration. One patient had an initial response to plasmapheresis, which allowed assisted mechanical ventilation to be discontinued. This improvement was not sustained, and the patient subsequently died in respiratory failure. Three patients survived to be dismissed from the hospital after they were weaned from mechanical ventilation.

Outcome of respiratory failure in hematologic malignancy.

We reviewed records of patients with hematologic malignancy requiring mechanical ventilation (MV) from 1976 to 1985 (excluding postoperative MV less than 48 hours). There were 119 episodes in 116 patients. In-hospital mortality was 82 percent. Of 21 (18 percent) episodes survived, median duration of survival was 12 months. Survivors did not differ from nonsurvivors in age, leukocyte count, or duration of MV. Survival for chronic lymphocytic leukemia was 42 percent, for other leukemias 16 percent, Hodgkin's disease 29 percent, and non-Hodgkin's lymphomas, 6 percent. Bronchoscopy was performed in 28 patients, resulting in a diagnosis of infection, hemorrhage, or malignancy in 19 cases. Open lung biopsy (OLB) was obtained in 23 patients, yielding a diagnosis of interstitial inflammation or fibrosis (13 cases), drug effect (three), malignancy (two), hemorrhage (one), Pneumocystis (seven), aspergillosis (two), and Legionella (one). Only two patients survived following OLB. Despite intensive management and adequate diagnosis, respiratory failure in patients with hematologic malignancy carries a high mortality. Although these data may help identify groups with a limited prognosis for long-term recovery, patient care must be individualized.

Hospital and posthospital survival in patients mechanically ventilated for more than 29 days.

Experience with prolonged mechanical ventilation has improved over recent years. Retrospective analysis of the records of 104 patients older than 16 years of age who were mechanically ventilated for more than 29 days over a 29-month period from May 1986 to October 1988 revealed the following findings. The mean patient age was 66.3 +/- 15.7 years (SD). The mean number of in-hospital ventilator days was 59.9 +/- 36.7 days (range, 29 to 247 days). The mean number of days of oral or nasal endotracheal intubation prior to tracheostomy (96 patients) was 21.5 +/- 14.2 days. The mean length of hospital stay for the 104 patients was 79.9 +/- 45.4 days. The majority of the 104 patients (82.6 percent) were surgical patients. Nine patients left the hospital receiving extended mechanical ventilation. Mortality was highest in multiple organ system failure and lowest among the trauma patients. The total days of mechanical ventilation did not appear to be related to mortality if patients older than 16 years survived for seven days. Postdischarge survival of the 53 of 60 patients who survived and whom we were able to contact was 67 percent at one year and 56 percent at three years.

Preoperative pulmonary preparation of patients with chronic obstructive pulmonary disease: a prospective study.

A group of 157 patients with chronic obstructive pulmonary disease who were treated before surgery using a standardized pulmonary preparation underwent physiologic assessment both before and after the prophylactic program. The postoperative course of each patient also was evaluated to assess the incidence of respiratory morbidity and mortality. Although many physiologic values were statistically improved after the pulmonary preparation, most of the changes are of doubtful functional significance. It is difficult to determine which patients will develop pulmonary complications not requiring mechanical ventilation, but the group requiring this type of support appears to be predictable on the basis of the severity of their pulmonary functional impairment and their lack of response to the standard pulmonary preparation used. The single most reliable test for this purpose was the mean forced expiratory flow during the middle half of the forced vital capacity. The frequency of postoperative respiratory complications was related to the type of operation, with the highest incidence occurring in the group that had extensive upper-abdominal surgery. While the occurrence of these complications was significantly reduced in patients undergoing a standard preoperative pulmonary preparation, the explanation for the beneficial effect of this procedure is not apparent.

Plasmapheresis in the treatment of ventilator-dependent myasthenia gravis patients. Report of four cases.

During a 42-month period, we used plasmapheresis to treat four cases of myasthenia gravis with refractory respiratory failure. All four patients were ventilator dependent for prolonged periods and were not responding to management with cholinesterase inhibitors and corticosteroids. All four patients rapidly responded to the plasmapheresis; respiratory muscle strength returned sufficiently to allow discontinuation of assisted mechanical ventilation and removal of the artificial airway. In our experience, plasmapheresis is indicated in the treatment of the myasthenia gravis patient with respiratory failure which is refractory to conventional drug therapy.

Unexplained diaphragmatic paralysis: a harbinger of malignant disease?

The records of 103 male and 39 female patients with unexplained diaphragmatic paralysis were reviewed. A probable cause of the paralysis was not revealed by the initial history, physical examination, or review of plain chest roentgenograms. Paralysis occurred on the left in 82 patients (58%), on the right in 58 (41%), and bilaterally in two (1%). Initially, 64 patients (45%) had symptoms; dyspnea, cough, and chest wall pain were the most common. Long-term follow-up showed the best prognosis to be for patients with chest wall pain and cough (improvement in 82% and 78%, respectively); dyspnea improved in only 34% of patients with this complaint. Intrathoracic malignant lesions with phrenic nerve involvement were subsequently diagnosed in five patients (3.5%) and progressive neurogenic atrophy in one (0.7%). Roentgenographic follow-up showed return of normal diaphragmatic position in only 12 instances (9.2%). Patients with unexplained diaphragmatic paralysis are unlikely to have an underlying occult malignant or neurologic process, but recovery of diaphragmatic function is also unlikely and subsidence of related symptoms is variable.

Post-ICU weaning from mechanical ventilation: the role of long-term facilities.

A review of the largest observational studies on post-ICU weaning from prolonged mechanical ventilation yields evidence that more than half of such patients can be successfully liberated from mechanical ventilation. Success is likely to fall within a 3-month window, with late successes and partial ventilator independence still possible thereafter. There is a uniformity of practice in finishing difficult weaning with self-breathing trials of increasing duration.

Postoperative respiratory care after transsternal thymectomy in myasthenia gravis. A 3-year experience in 53 patients.

During a three-year period, 53 patients with myasthenia gravis underwent transsternal thymectomy by a partial sternum-splitting technique at our institution. This procedure was carried out (1) because an x-ray film or a computed tomography scan had suggested the presence of a thymoma or (2) to manage symptoms of myasthenia gravis. In 41 patients the endotracheal tube was removed in the post-anesthesia recovery room. The remaining 12 patients were extubated in the Respiratory Care Unit--in five, after prolonged mechanical ventilation. From our experience, the only factor useful for predicting the probable need for prolonged postoperative mechanical ventilation is the degree of bulbar involvement. Patients in Osserman classification groups 3 and 4 have an extremely high incidence of postoperative respiratory failure. Consideration should be given to the use of preoperative plasmapheresis in myasthenia gravis patients who have significant bulbar symptoms.