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Biomedical subjects

B A Staats

Publications and source records attributed to B A Staats.

At least 19 recordsLinked to original sources
PubMed1999

Successful treatment of obstructive sleep apnea with use of nasal continuous positive airway pressure in three patients with mucosal hemangiomas of the oral cavity.

Cysts and benign tumors are uncommon causes of obstructive sleep apnea (OSA), and surgical removal is usually favored. In patients in whom an operation poses a high risk, however, nasal continuous positive airway pressure (CPAP) may prove beneficial. We describe three patients with hemangiomas of the oral cavity in whom polysomnography revealed moderate to severe OSA. In all three patients, nasal CPAP effectively decreased sleep-related disordered breathing events and dramatically improved their sleep. To our knowledge, this is the first report of OSA associated with hemangiomas involving the upper airway. Our experience suggests that nasal CPAP therapy is effective and well tolerated in such patients.

Female↗
PubMed1998

"Postpolio" sequelae and sleep-related disordered breathing.

OBJECTIVE: To analyze the clinical manifestations and various types of sleep-related disordered breathing (SRDB) in patients with a history of poliomyelitis and with current "postpolio" sequelae (PPS). MATERIAL AND METHOD: We retrospectively reviewed the medical records of 108 consecutive patients with PPS and sleep disturbances encountered during an 11-year period at Mayo Clinic Rochester and abstracted the features of acute polio, PPS, and results of sleep evaluation (overnight oximetry or polysomnography). Only those patients who were not receiving ventilatory support were included in the study. RESULTS: The features of PPS were dyspnea, fatigue, new weakness, and musculoskeletal pain. Of the 108 patients, 35 fulfilled the inclusion criteria. Sleep evaluations revealed three general types of disturbances: obstructive sleep apnea (group O, N = 19); hypoventilation (group H, N = 7); and both (group OH, N = 9). The mean apnea/hypopnea index was 37, 4, and 16 per hour in patients in groups O, H, and OH, respectively (P < 0.05), and the mean arterial carbon dioxide tension was 39, 60, and 55 mm Hg in these respective study groups (P < 0.05). The overall mean age at onset of symptoms of SRDB was 47 years, and the mean latent period after acute polio was 37 years. Hypersomnolence was the commonest SRDB symptom, present in 32 of the 35 patients. Snoring was noted in 100% of patients in group O, 0% in group H, and 67% in group OH. Patients in group O were obese and had normal lung function. Patients in group H tended to have normal weights and a history of diffuse neurologic deficits involving the trunk during the acute episode of polio. Scoliosis, restricted lung function, cor pulmonale, and decreased maximal respiratory pressures were common in patients in group H. Patients in group OH had overlapping features of those in groups O and H. CONCLUSION: In patients with PPS, we identified three patterns of sleep disturbances--obstructive sleep apnea, hypoventilation, and a combination of both. These groups are characterized by clinical features and by results of arterial blood gas determinations, overnight oximetry, and polysomnography. SRDB is a late sequela of poliomyelitis, and clinical evaluation should include information about sleep.

Carbon Dioxide↗
PubMed1998

Long-term clinical experience with transtracheal oxygen catheters.

OBJECTIVE: To evaluate and discuss the use of transtracheal oxygen catheters for the treatment of chronic hypoxemia and to discuss the complications associated with the placement and care of these devices. DESIGN: We conducted a retrospective study at a tertiary medical center and reviewed the pertinent literature. MATERIAL AND METHODS: The medical records of 56 patients who received a transtracheal oxygen catheter between January 1987 and June 1992 at our institution were reviewed for demographic data, diagnosis leading to catheter placement, complications related to catheter use, reason for catheter removal, and duration of use. Follow-up results were established by documentation in the medical records or telephone interview. RESULTS: During the study period, 39 men and 17 women received a transtracheal catheter. More than half the patients (52%) had chronic obstructive pulmonary disease. The duration of use of the catheter ranged from 2 days to more than 6 years, and the most frequent cause for removal of the catheter was death. Of the 56 patients, 42 died with the catheter in place, 24 within the first year after placement. Complications ranged from mucous plugging (38 % of patients) to pneumothorax (4%), and no patient died of a catheter-related complication. Overall, 55% of patients had their catheter for less than 1 year after placement. CONCLUSION: In patients with transtracheal oxygen catheters, problems related to mucous plugging are common, but severe complications such as pneumothorax and pneumomediastinum are uncommon. Although selection factors that would identify ideal candidates for transtracheal oxygen therapy have not been established, such a catheter is best placed in highly motivated patients who can physically manage the daily care of this device.

Adult↗
PubMed1997

alpha1-antitrypsin gene mutation hot spot associated with the formation of a retained and degraded null variant [corrected; erratum to be published].

Null alpha1-antitrypsin (alpha1AT) alleles represent the end of a continuum of variants associated with profound alpha1AT deficiency and an increased risk of emphysema. This study characterizes the molecular basis of QOclayton, a new example of an alpha1AT null allele arising from a mutational hot spot in the alpha1AT gene. The QOclayton allele is identical to the normal M1(V213) alpha1AT allele except for an insertion of a cytosine. This insertion occurs in the alpha1AT sequence which normally has seven cytosines corresponding to amino acid residues 360 to 362. The QOclayton mutation is located in the same reiterated DNA sequence as the alpha1AT QObolton deletion mutation and the insertion mutation allele QOsaarbruecken. The QOclayton cytosine insertion causes a 3' frameshift and results in the formation of a termination codon at residue 376, the same consequence as the alpha1AT QOmattawa mutation (L353 T-insertion with a 3' frameshift). To determine the molecular mechanisms responsible for the absence of alpha1AT associated with the QOclayton gene, an in vitro model of QOclayton was established using Chinese hamster ovary cells (CHO) transfected with the QOclayton gene. These cells were evaluated for alpha1AT mRNA expression, protein synthesis and secretion. Although the QOclayton gene expresses a similar amount of alpha1AT mRNA as compared with the normal alpha1AT gene, no QOclayton protein is secreted. Protein trafficking and double-label immunofluorescence demonstrate that the QOclayton protein is retained in the rough endoplasmic reticulum or pre-Golgi compartment and is degraded (t1/2 = 6.5 h). Since QOmattawa, QObolton, and QOsaarbruecken have similar termination sites in the alpha1AT mRNA, they may share a similar intracellular fate.

Animals↗
PubMed1994

Unexplained dyspnea.

Dyspnea is a common symptom that is difficult to define and can result from a wide variety of causes. This complex sensation that arises from multiple stimuli involves both subjective perceptions and objective reactions. In the assessment of patients with dyspnea, use of a systematic approach to determine the precipitating factors and the degree of breathlessness is important. Although many diseases may produce dyspnea, two thirds of the cases result from a pulmonary or cardiac disorder. Neuromuscular and psychogenic causes should also be considered. A comprehensive history, physical examination, and basic laboratory tests are important in the initial assessment; however, the diagnosis may depend on specialized testing, the results of which may differ from the initial clinical impression. Initial testing should include electrocardiography, chest roentgenography, hemoglobin determination, thyroid function, and spirometry with use of a bronchodilator. More specialized evaluation includes detailed pulmonary function testing and echocardiography. As shown in our illustrative case, cardiopulmonary exercise testing is important for evaluation of unexplained dyspnea when initial test results are nondiagnostic. Accurate diagnostic data are critical for choosing appropriate treatment.

Adult↗
PubMed1992

The Cushing syndrome induced by bronchial carcinoid tumors.

OBJECTIVES: To define the clinical spectrum of bronchial carcinoid tumors in patients presenting with the Cushing syndrome, to evaluate the role of chest radiographs and computed tomography in their diagnosis, to review the characteristic histologic features, and to determine patient outcome. DESIGN: Retrospective analysis of consecutive patients. SETTING: A referral-based medical center. PATIENTS: Fifteen consecutive patients with the Cushing syndrome evaluated at the Mayo Clinic with histologically proven bronchial carcinoid tumors. MEASUREMENTS: Clinical, radiographic, and histologic features. RESULTS: The Cushing syndrome was the initial clinical presentation, and bronchial carcinoid tumors were found later in all 15 patients. The diagnosis of carcinoid tumor was proved histologically in all cases. Ten biopsies showed typical carcinoid tumors, three were histologically atypical, and three were metastatic. Corticotropin was detected by immunostaining in seven of these tumors. Biochemical analysis showed marked elevations of circulating corticotropin with a mean serum value of 156 +/- 58 pmol/L (normal, 4 to 22 pmol/L). Additional clinical features included hypokalemia in six patients and glucocorticoid response to either high-dose dexamethasone or metyrapone in 6 of 13. These hormonally active carcinoid tumors were frequently radiographically occult, with 10 of 15 patients initially having normal chest radiographs. Computed tomography was successful in locating carcinoid tumors in five patients with negative chest radiographs evaluated after 1980. All five remaining patients with normal chest radiographs evaluated before 1980 eventually developed nodular lesions on standard chest radiography from 1 to 10 years later. Ten patients achieved complete remission and two patients, partial remission of the Cushing syndrome after surgical resection. Three patients continued to have symptomatic glucocorticoid excess due to metastatic disease. CONCLUSIONS: Although uncommon, the Cushing syndrome may be the initial clinical manifestation of an otherwise indolent bronchial carcinoid tumor. Radiographic imaging of occult lesions can be successfully accomplished with computed tomography. Surgical resection is curative in most patients with this disorder.

ACTH Syndrome, Ectopic↗
PubMed1992

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.

Dyspnea↗
PubMed1991

Pulmonary mechanics in lymphangioleiomyomatosis.

Standard pulmonary function and mechanics studies were done in eight female patients with lymphangioleiomyomatosis diagnosed by open-lung biopsy. Five patients were studied before hormone treatment. The mean age of the patients was 40 +/- 3 (SEM) years. Two of the eight had a smoking history of 10 pack-years or more, but all had quit smoking several years before evaluation. There was a trend toward increased total lung capacity (114 +/- 7% expressed as mean of percentage predicted +/- SEM) and increased residual volume (207 +/- 24%). Of the eight patients seven had expiratory obstruction as evidenced by the reduced forced expiratory volume in 1 s/forced vital capacity ratio [( FEV1/FVC] 61 +/- 6%). Steady-state diffusing capacity for carbon monoxide was reduced in seven of the patients (57 +/- 12%). Pulmonary mechanics studies performed in a body plethysmograph revealed a modest reduction in retractive force both at total lung capacity and at 90% total lung capacity (67 +/- 10 and 59 +/- 9%, respectively). Static compliance tended to be increased (128 +/- 19%). Pulmonary flow resistance was markedly elevated (266 +/- 46%). Maximal flow-static recoll curves revealed that in the seven patients with expiratory obstruction the cause was predominantly airway narrowing rather than loss of lung elastic forces. We conclude that in this group of patients with lymphangioleiomyomatosis there was no evidence for significant restriction. Although there was some decrease in retractive force consistent with emphysema, expiratory flows were reduced predominantly because of airway narrowing or obstruction rather than loss of pulmonary elastic recoil forces.

Adult↗
PubMed1990

A prospective study of airway reactivity before bone marrow transplantation.

The purposes of this study were to assess baseline airway function and to determine the frequency of airway reactivity in patients before bone marrow transplantation (BMT). The ratio of the forced expiratory volume at 1 second to the forced vital capacity (FEV1/FVC) was the measure of baseline airflow. Using methacholine challenge, we tested 53 patients before conditioning chemotherapy, total-body irradiation, and BMT. All patients had a baseline FEV1/FVC of 70% or more. The mean baseline FEV1/FVC was 84(+)/- 6%. The response to methacholine challenge was defined by the change in FEV1 from baseline (delta FEV1). A positive response (delta FEV1 of 20% or more) occurred in 11 of 53 patients (21%), a borderline response of (delta FV1 of less than 20% but greater than or equal to 10%) was was found in 10 (19%), and no response (Delta FEV1 of less than 10%) was elicited in 32 (60%). In our group of patients with a positive or borderline response to methacholine, we found no significant relationship to baseline FEV1/FVC, smoking history, hematologic diagnosis or study, or major post-BMT pulmonary complications including bronchiolitis obliterans. We concluded that pretransplantation airway reactivity, as measured by methacholine challenge and in the setting of normal baseline FEV1/FVC, was common before BMT. The presence of a borderline or positive response to methacholine challenge before transplantation was not associated with the development of either clinical or pathologically proven posttransplantation bronchiolitis obliterans.

Adolescent↗
PubMed1990

Obstructive sleep apnea syndrome.

Obstructive sleep apnea syndrome is the most common cause of hypersomnolence in patients referred to sleep disorders centers. This type of sleep apnea is characterized by loud snoring, nocturnal oxyhemoglobin desaturation, and disrupted sleep that leads to daytime hypersomnolence. The anatomic configuration of the pharynx and the physiologic responses to occlusion of the upper airway play a major role in the pathogenesis of this disorder. Polysomnography can accurately identify obstructive sleep apnea, and the multiple sleep latency test allows an objective measurement of daytime alertness. Weight loss and training the patient to sleep in a lateral position are frequently used to alleviate mild cases. Nasally applied continuous positive airway pressure is an extremely effective modality for treating moderate and severe obstructive sleep apnea. Surgical correction of obvious anatomic defects has a role in diminishing obstructive sleep apnea, but the exact role of surgical intervention in patients without obvious anatomic defects remains unknown. The choice of therapy should be tailored to the individual patient with sleep apnea, and careful follow-up is essential to ensure a positive response to therapy.

Humans↗
PubMed1990

Exercise cardiorespiratory function in adolescents with pectus excavatum. Observations before and after operation.

We studied 12 children with pectus excavatum (mean age, 13.8 years) using pulmonary function and exercise testing. Eight patients had surgical repair and were studied before and after repair. Four patients did not have repair and were tested twice. The degree of chest wall deformity in the two groups was similar. All patients reached 86% or more of their maximal predicted heart rate with exercise. Total lung capacity decreased 8% (p less than 0.01) after operation. In the nonoperated control group, total lung capacity was similar during both studies. The ratio of ventilation at maximal exercise to maximal voluntary ventilation was 68% +/- 12% before and 66% +/- 9% after operation in the operated group and 69% +/- 18% and 79% +/- 30% at two studies in the nonoperated group (nonsignificant changes). Maximal oxygen uptake was 36.1 +/- 4.4 ml/kg/min preoperatively and 38.1 +/- 8.1 postoperatively and 41.2 +/- 7.3 ml/kg/min and 43.0 +/- 6.9 on two studies in the nonoperated group (nonsignificant changes). Cardiac output and stroke volume increased appropriately with exercise both before and after operation. Operation had no physiologically significant effect on the cardiorespiratory response to exercise. Slight changes in cardiorespiratory function occurred in both operated and nonoperated subjects. These results emphasize the importance of studying patients before and after operation and of using a control group.

Adolescent↗
PubMed1989

Carbon monoxide diffusing capacity of the lungs determined by single-breath and steady-state exercise methods.

We measured carbon monoxide diffusing capacity of the lungs (DL,CO) by both the resting single-breath (SB) and steady-state (SS) exercise methods in 95 patients referred for pulmonary function testing. A 10-second breath-holding method was used for the SB test. DL,CO (SS) was measured during the last minute of a 3-minute exercise test on a 9-inch step. Results of the two methods showed good agreement, the SB-SS difference averaging -0.70 (SD, 3.39) ml/min per mm Hg. The difference between the two methods was not correlated with other measurements of pulmonary function except minute ventilation during the exercise performed in the DL,CO (SS) procedure. In a separate study of laboratory personnel, the day-to-day variabilities of the two tests were similar (SD, 1.4 ml/min per mm Hg). Alveolar volume obtained by helium dilution during the SB test was comparable to total lung capacity (TLC) estimated by multiple-breath nitrogen washout in patients without severe airway obstruction. In severe airway obstruction, the mean SB alveolar volume was 13.8% less than the TLC by nitrogen washout, a difference that may be useful as an indicator of inefficiency of gas mixing in the lungs. We conclude that the SB and SS exercise methods provide similar estimates of DL,CO in patients referred to a pulmonary function laboratory.

Adult↗
PubMed1989

Factitial leg ulcers associated with an unusual sleep disorder.

A 19-year-old woman presented with a 14-month history of multiple, factitially induced, full-thickness leg ulcers. Nocturnal polysomnography with video monitoring revealed a short sleep latency and frequent sleep stage changes. Rapid eye movement sleep was absent. All stages of non-rapid eye movement sleep were associated with leg rubbing. After treatment that included avoidance of daytime naps and administration of chlorpromazine at bedtime, affect, daytime behavior, nocturnal sleep, and the ulcers improved markedly. To our knowledge, there are no reports of factitial dermatosis associated with disordered sleep. Our findings suggest that abnormal sleep may play a role in initiating or perpetuating factitial dermatoses. This case illustrates that polysomnography and video monitoring may be indicated in the evaluation of patients with factitial dermatoses.

Adult↗