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Biomedical subjects

R P Byrd

Publications and source records attributed to R P Byrd.

At least 19 recordsLinked to original sources
PubMed2002

The effect of bi-level positive airway pressure on postoperative pulmonary function following gastric surgery for obesity.

The severely obese patient has varying degrees of intrinsic reduction of expiratory flow rates and lung volumes. Thus, the severely obese patient is predisposed to postoperative atelectasis, ineffective clearing of respiratory secretions, and other pulmonary complications. This study evaluated the effect of bi-level positive airway pressure (BiPAP) on pulmonary function in obese patients following open gastric bypass surgery Patients with a body mass index (BMI) of at least 40 kg/m2 who were undergoing elective gastric bypass were eligible to be randomized to receive either BiPAP during the first 24 h postoperatively or conventional postoperative care. Patients with significant cardiovascular and pulmonary diseases were excluded from the study. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), peak expiratory flow rate (PEFR), and percent hemoglobin oxygen saturation (SpO2) were measured preoperatively, and on postoperative days 1, 2, and 3. Twenty-seven patients were entered in the study 14 received BiPAP and 13 received conventional postoperative care. There was no significant difference preoperatively between the study and control groups in regards to age, BMI, FVC, FEV1.0, PEFR or SpO2. Postoperatively expiratory flow was decreased in both groups. However, the FVC and FEV1.0 were significantly higher on each of the three consecutive postoperative days in the patients who received BiPAP therapy. The SpO2 was significantly decreased in the control group over the same time period. Prophylactic BiPAP during the first 12-24 h postoperatively resulted in significantly higher measures of pulmonary function in severely obese patients who had undergone elective gastric bypass surgery. These improved measures of pulmonary function, however, did not translate into fewer hospital days or a lower complication rate in our study population of otherwise healthy obese patients. Further study is necessary to determine if BiPAP therapy in the first 24 postoperative hours would be of benefit in severely obese patients with comorbid illnesses who have undergone elective gastric bypass.

Adult↗
PubMed2001

Utility of rifampin blood levels in the treatment and follow-up of active pulmonary tuberculosis in patients who were slow to respond to routine directly observed therapy.

STUDY OBJECTIVE: The standard daily dose of rifampin in directly observed treatment of Mycobacterium tuberculosis (TB) is 600 mg, taken orally. The purpose of this study was to assess the efficacy of standard dose rifampin therapy in patients who were slow to respond to routine directly observed therapy (DOT). METHODS: Patients with non-drug-resistant pulmonary TB who were receiving 600 mg of oral rifampin by DOT were eligible for inclusion. Patients were deemed slow to respond if their sputum smears and cultures remained positive for M tuberculosis and if the patient's condition did not improve clinically or radiographically after 3 months of treatment. Serum rifampin levels were ascertained to determine the adequacy of the standard rifampin dosing. Patients with subtherapeutic blood levels had their rifampin dose increased to 900 mg, and rifampin levels were repeated. Rifampin dosage was increased again if blood levels were still subtherapeutic. No antitubercular medications were added to the treatment regimen. The total weekly dose of the other standard treatment drugs was not increased. RESULTS: Of 124 new patients with active pulmonary TB, 6 patients were identified as slow to respond to the standard antitubercular DOT. All six patients had subtherapeutic serum rifampin levels. All six patients responded clinically, radiographically, and mycobacteriologically after an increase in rifampin dosage to reach target drug blood level. CONCLUSIONS: Standard dosing with rifampin resulted in a poor clinical response and subtherapeutic serum levels in six patients. Increasing the dosage of rifampin improved the outcome without additional side effects. In TB patients who are slow to respond to standard treatment, an inadequate dose of rifampin should be suspected. Current antituberculer drug administration does not include adjusted dosage for rifampin.

Administration, Oral↗
PubMed2001

A rare cause of dyspnea and fibrocystic pulmonary disease.

Tracheobronchomegaly (TBM) is a disorder of the major airways characterized by an enlargement of the trachea and main stem bronchi. It is thought to result from a congenital connective tissue defect that results in the trachea and main bronchi becoming flaccid. Although TBM is considered rare, it may be more common than is generally recognized, and may be a seldom-diagnosed cause of chronic lung disease.

Aged↗
PubMed2001

Influenza A pneumonia with rhabdomyolysis.

Influenza A pneumonia accounts for a significant number of the community-acquired pneumonias in the United States. While myalgia is a common complaint in influenza A infection, few cases of rhabdomyolysis associated with this virus have been described. Although it has been recently recognized that rhabdomyolysis complicating certain bacterial pneumonias has important prognostic implications, rhabdomyolysis in the setting of influenza A pneumonia does not appear to carry the same prognostic significance.

Aged↗
PubMed2001

Cat cuddler's cough.

Pasteurella multocida typically causes cutaneous infections in humans following animal bites or scratches. Primary pulmonary disease, however, can occur in humans after inhalation of airborne particles or by aspiration of colonized or infected nasopharyngeal secretions containing this organism. Symptoms of P. multocida pulmonary infection in humans are variable, ranging from cough with or without hemoptysis to severe prostration. P. multocida infection of the lower respiratory tree has a predilection for elderly patients with underlying lung pathology, especially chronic obstructive pulmonary disease and bronchiectasis. This report reminds the clinician that P. multocida can cause pulmonary infection in patients without underlying lung disease, and stresses the importance of careful history when presented with an indolent infection.

Aged↗
PubMed2001

Nontubercular mycobacterial pulmonary infection in immunocompetent men.

BACKGROUND: Nontubercular mycobacteria (NTM) are increasingly recognized to cause lung disease in immunocompetent patients. We studied the occurrence of pulmonary infection due to NTM in immunocompetent men. METHODS: We retrospectively analyzed all sputum mycobacterial cultures at our institution over a 5-year period. Charts were reviewed to identify patients who met the American Thoracic Society's criteria for mycobacterial pulmonary infection. RESULTS: From the 7,380 sputum mycobacterial cultures obtained, 46 male patients had NTM identified. Forty-two patients were immunocompetent. Five of these patients were found to have NTM--2 with Mycobacterium kansasii, 2 with Mycobacterium avium-intracellulare, and 1 with Mycobacterium gordonae. All 5 patients responded to antimycobacterial therapy. CONCLUSION: Twelve percent of our population of immunocompetent men from whom NTM were isolated from sputum were infected. This study should alert the clinician that NTM cause treatable pulmonary disease in immunocompetent men.

Aged↗
PubMed2001

Simvastatin-diltiazem drug interaction resulting in rhabdomyolysis and hepatitis.

Simvastatin, a hydroxymethyl glutarate coenzyme A (HMG-CoA) reductase inhibitor, is a commonly used cholesterol lowering agent. The long-term safety profile of simvastatin, established over ten-years of clinical use, is excellent. Both rhabdomyolysis and hepatitis, however, are recognized toxic effects of this medication, and generally occur when the patients are taking more than 40 mg of simvastatin a day. Potent inhibitors of the cytochrome P450 3A4 (CYP3A4) enzyme increase the incidence of simvastatin toxicity. Calcium channel blockers are weak inhibitors of the CYP3A4 enzyme. Diltiazem is known to increase the serum concentration of simvastatin. Many patients who take both simvastatin and diltiazem require lower doses of simvastatin to achieve the recommended reduction in cholesterol. Since diltiazem is known to increase plasma levels of lovastatin, a similar phenomenon may occur with simvastatin. Our patient had been stable for three years on simvastatin therapy. His rhabdomyolysis and hepatitis coincided with the addition of diltiazem. This is the first report of the combined toxicities of rhabdomyolysis and hepatitis being induced by the addition of diltiazem to simvastatin therapy. This patient serves as a reminder to the clinician of the potential interaction of these two commonly used drugs.

Calcium Channel Blockers↗
PubMed2001

Spontaneous resolution of a giant pulmonary bulla.

Giant bullae occur most often in individuals who chronically inhale tobacco smoke. The natural history of these bullae is unpredictable, although the majority of them increase gradually in size and cause worsening respiratory function. Complete spontaneous resolution of a giant bulla is a rare occurrence, with only eight cases reported in English literature. Most of the cases of spontaneous resolution of giant bullae are thought to have resulted from an infectious process leading to closure of the communication between the airways and the bulla. However, resolution of a bulla has been associated with adenocarcinoma of the lung.

Blister↗
PubMed2000

Difficult-to-manage asthma. How to pinpoint the exacerbating factors.

In difficult-to-manage asthma, effective control depends on identification and alleviation of exacerbating factors, such as ongoing allergen exposure, chronic sinusitis, GERD, and emotional stress. Level of compliance with the prescribed medication regimen should be evaluated in all patients. Hormonal factors (i.e., menses, use of exogenous hormones by female patients, and hyperthyroidism) also can exacerbate asthma. When aggressive management fails, the possibility of a misdiagnosis should be considered. Other conditions that can mimic asthma include COPD, congestive heart failure, airway obstruction due to various causes, vocal cord dysfunction, and esophageal spasm. Referral to an asthma specialist is advised in severe or resistant cases.

Algorithms↗
PubMed2000

Cicatricial pemphigoid with an upper airway lesion.

Cicatricial pemphigoid is an unusual mucocutaneous disease that is characterized by subepidermal blister formation involving the oral and conjunctival membranes. The oral lesions are expressed as erythema and induration and have rarely been associated with upper airway obstruction. We report the case of a patient with dyspnea and an abnormal flow-volume loop who was found to have subglottic compromise due to cicatricial pemphigoid. Immunosuppressive therapy improved his symptoms and air flow.

Humans↗
PubMed2000

Tracheal lipoma: a rare intrathoracic neoplasm.

Primary tracheal lipomas are extremely rare neoplasms. The typical patient is a middle-aged man with complaints of cough and shortness of breath. Often, the diagnosis is delayed, and patients are treated for asthma or bronchitis. The diagnosis of a tracheal lipoma is best approached by computed tomography (CT) and bronchofibroscopy. Tracheobronchial lipomas may be successfully excised endoscopically or by laser therapy. Open surgical resection is required when the lipoma extends extraluminally.

Asthma↗
PubMed2000

Noncaseating granulomatous disease in common variable immunodeficiency.

Patients with common variable immunodeficiency (CVID) are occasionally recognized to have a concurrent noncaseating granulomatous disease. The granulomatous disease (GD) associated with CVID shares many clinical properties typical of sarcoidosis. Some investigators speculate that the GD-CVID is actually sarcoidosis that is expressed atypically because of the patient's immunodeficiency. Clinical differences, however, have led other investigators to speculate that the GD-CVID is a distinct "sarcoid-like" granulomatous process.

Aged↗
PubMed2000

Reevaluation of anaerobic blood cultures in a Veteran population.

BACKGROUND: Studies suggest that the selective use of anaerobic blood cultures may represent a more cost-effective laboratory approach when anaerobic bacterial infection is suspected. METHODS: A 5-year retrospective study was done at a Veterans' Affairs hospital to determine the utility of routinely including anaerobic blood culture when sampling for bacteremia. RESULTS: A total of 22,075 anaerobic blood cultures were collected from our adult population. Significant anaerobic pathogens were isolated from only 0.14% of these blood cultures. An anaerobic infection could have been suspected in 92% of our patients. CONCLUSIONS: Significant anaerobic bloodstream infections occurred in only 0.14% of blood cultures. In addition, the majority of the patients identified with anaerobic bacteremia had clinical conditions that would have suggested a high likelihood of anaerobic bacteremia. These observations suggest that selective rather than routine use of anaerobic blood cultures may be appropriate in a veteran population.

Adult↗
PubMed2000

Re-expansion pulmonary edema following puncture of a giant bulla.

Ipsilateral pulmonary edema may occur in a lung that has been rapidly reinflated after a period of collapse. The syndrome of re-expansion pulmonary edema is associated with variable degrees of hypotension and hypoxemia. In its extreme form, it may result in cardiac arrest and death. The initial cause of uninflated pulmonary parenchyma described with re-expansion pulmonary edema has typically been either a large undrained pleural effusion or a pneumothorax. The authors describe a patient in whom re-expansion pulmonary edema developed when inadvertent puncture of large emphysematous bullae released previously atelectatic lung.

Blister↗
PubMed1999

Delayed chest radiographs and the diagnosis of pneumothorax following CT-guided fine needle aspiration of pulmonary lesions.

We prospectively studied 64 consecutive patients on whom computerized tomography-guided fine needle aspirations (CT-FNA) of pulmonary lesions were performed to determine whether obtaining a delayed chest radiography (CXR) after CT-FNA is helpful in the diagnosis of post-procedure pneumothorax (PTX). Two of the 64 patients developed a delayed PTX. Only one of the patients with a delayed PTX required chest tube drainage. If patients have no evidence of a PTX immediately after a CT-FNA by CT scan then a delayed CXR adds little to care of these patients.

Aged↗
PubMed1999

Comparison of the use and accuracy of methods for determining pleural fluid pH.

BACKGROUND: The blood gas analyzer (BGA) has been considered the "gold standard" for pleural fluid pH determination. METHODS: We report the various methods used to measure pleural fluid pH by 277 acute care institutions who responded to a mailed questionnaire. The techniques used included the BGA (32%), dip stick or pH indicator paper (56%), and a pH meter (12%). We tested 36 consecutive exudative pleural fluid samples using each method. RESULTS: The alternative methods were incomparable to accurately measuring pleural fluid pH by the BGA, with a mean difference of 0.16 pH unit. With a delay in testing, the pH of the pleural fluid was more alkalotic and variable, with a mean difference of 0.039 pH unit. CONCLUSIONS: Clinicians should be encouraged to test selected samples for pleural fluid pH by the BGA when accurate measurements will influence therapy.

Blood Gas Analysis↗