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Biomedical subjects

S A Sahn

Publications and source records attributed to S A Sahn.

At least 109 records · Page 6Linked to original sources
PubMed1989

A prospective comparison of IMV and T-piece weaning from mechanical ventilation.

Two hundred (200) consecutive medical and surgical patients requiring mechanical ventilation were entered into a prospective randomized trial of weaning by either intermittent mandatory ventilation (IMV) or T-piece. Patients in these groups were of similar age and sex and had the same total ventilation time (TVT). The study design provided equal time for each weaning mode after specific criteria for oxygenation and ventilation were satisfied (PaO2 greater than 55 mm Hg on FIO2 less than 0.5; VE less than 12 L/min and two of the following four parameters: MVV greater than 2 VE, VT greater than 5 ml/kg, FVC greater than 10 ml/kg, NIF less than or equal to -20 cm H2O). Of the original 200 patients 165 were entered into the weaning phase; 35 patients were withdrawn prior to weaning due to the discretion of the attending physician or protocol error. Weaning time was not different between the IMV (5.3 +/- 1.2 h, mean +/- SEM) and T-piece groups (5.9 +/- 1.4 h, p = NS). Of the 165 patients, 155 (93 percent) were weaned successfully by protocol, 79 in the IMV and 76 in the T-piece group. Of 155 patients, 136 (88 percent) were weaned on the first attempt by protocol. Of the 19 who were not weaned, 11 were weaned successfully on the second and five on the third trial; three patients required three-day weans. We conclude that clinically stable patients who require short-term mechanical ventilation and meet standard bedside weaning criteria can be weaned efficiently by protocol using either IMV or T-piece techniques.

Adult↗
PubMed1989

Immediate chest roentgenography following fiberoptic bronchoscopy.

It is a common practice for some clinicians to obtain a chest roentgenogram immediately following FOB in an attempt to detect complications of the procedure, particularly pneumothorax; however, the roentgenogram adds substantially to the cost of FOB. It was our clinical impression that the diagnostic and therapeutic value of immediate chest roentgenography was minimal. Therefore, we reviewed 130 chest roentgenograms taken immediately after bronchoscopy that were obtained over 36 months. One hundred fourteen (88 percent) were unchanged from the most recent roentgenogram before bronchoscopy. Ten (8 percent) showed an increase in alveolar infiltrate due to bronchoalveolar lavage or hemorrhage. Five (4 percent) had changes presumably unrelated to the procedure. Only one patient had a pneumothorax on the roentgenogram taken immediately after bronchoscopy; however, the patient was symptomatic, and the pneumothorax was detected by fluoroscopy prior to the chest roentgenogram. Management of the patient's condition was not altered in a single case based upon findings on the chest roentgenogram. We conclude that the immediately postbronchoscopic chest roentgenogram rarely provides clinically useful information or detects a complication that is not suspected clinically; furthermore, it appears to have minimal impact, if any, on the management of a patient's condition.

Bronchoscopy↗
PubMed1988

Biliopleural fistula as a complication of percutaneous biliary drainage: experimental evidence for pleural inflammation.

We describe 3 patients in whom biliopleural fistulae complicated percutaneous biliary drainage. All patients had complete obstruction of their biliary tree because of malignancy. Biliopleural fistulae developed as a complication of inadvertent catheter removal in 2 patients and of catheter dysfunction in the third. Early reinstitution of biliary drainage and successful drainage of the pleural space led to complete recovery in all patients. An animal model to evaluate the effects of bile in the pleural space in normal rabbits revealed rapid absorption of bilirubin, the production of a polymorphonuclear-predominant exudative effusion with extremely high LDH levels, and resolution with a macrophage influx. We conclude that biliopleural fistulae are heterogeneous in their presentation, depending upon the persistence of biliary drainage into the pleural space, the volume of exudative effusion, and the presence of suppurative complications.

Aged↗
PubMed1988

Clinical features and outcome in patients with acute asthma presenting with hypercapnia.

To determine the clinical features and outcome of patients with hypercapnia from acute asthma, we examined 229 (62 men, 167 women) consecutive episodes of acute asthma over a 6-yr period. Sixty-one episodes were associated with hypercapnia at presentation (PaCO2 greater than 38 mm Hg). Men more commonly presented with hypercapnia: 31 of 62 (50%) men with acute asthma had hypercapnia compared with only 30 of 167 (18%) women (p less than 0.001). Patients with hypercapnia had a longer duration of chronic asthma and were more likely to be steroid-dependent. Hypercapnic patients had greater airway obstruction, respiratory rate, and pulsus paradoxus than did nonhypercapnic patients. Findings of a quiet chest on auscultation, inability to talk, and cyanosis also suggested the presence of hypercapnia. Five hypercapnic patients required mechanical ventilation, but hypercapnia did not prolong hospitalization. In nonventilated patients, hypercapnia resolved in a mean time of 5.9 h; 50% of hypercapnic episodes resolved by 4 h, and all resolved by 16 h. No patient presenting with normocapnia progressed to hypercapnia with therapy, and there were no deaths in either the hypercapnic group or the nonhypercapnic group. In patients with more than one admission, the PaCO2 of one episode correlated with the PaCO2 on a subsequent admission, suggesting a role for individual variation in ventilatory control. With appropriate medical therapy, most patients with hypercapnia from acute asthma have rapid reversibility, and mechanical ventilation usually can be avoided. However, these patients require close inhospital observation until it is certain that the acute asthmatic episode has resolved.

Acute Disease↗
PubMed1988

Effect of patient positioning on distribution of tetracycline in the pleural space during pleurodesis.

Thoracostomy tube drainage with tetracycline (TCN) instillation is an effective technique for management of recurrent, symptomatic, malignant pleural effusions. Although patient rotation through various positions after instillation of TCN has been advocated empirically, it has not been shown scientifically to be necessary and is often uncomfortable for the patient and time-consuming for personnel. Five patients with symptomatic, malignant pleural effusions were studied during pleurodesis using radiolabelled TCN. Scintigraphic imaging was done immediately after TCN instillation prior to patient rotation. Patients were rotated through six positions and multiple images were obtained at 30 and 120 minutes. Tetracycline dispersed throughout the pleural space within seconds. Patient positioning had no effect on the intrapleural distribution of TCN in four of the five patients. In one patient with loculated hydropneumothorax and trapped lung, rotation minimally improved distribution of TCN to the apex. Rotation during pleurodesis does not appear to be necessary in patients with a relatively normal pleural space. However, patient rotation enhances distribution of TCN when the lung is separated substantially from the chest wall, as with trapped lung. Possibly, in this situation the properties of fluid mechanics and capillary action no longer apply.

Adult↗
PubMed1988

Systemic absorption of tetracycline and lidocaine following intrapleural instillation.

Seven patients with symptomatic pleural effusions (six) and recurrent pneumothorax (one) underwent attempted pleurodesis using tetracycline. Lidocaine (150 mg), followed immediately by tetracycline (20 mg/kg), was instilled into the pleural space through a chest tube. Venous blood was obtained at 0, 15, 30, 60, and 120 minutes following instillation in order to determine concentrations of lidocaine and tetracycline. The mean peak serum concentration of lidocaine was 1.3 mu/ml +/- 0.4 microgram/ml (mean +/- SE) (range, 0.3 microgram/ml to 3.2 microgram/ml), and the mean time to peak serum concentration of lidocaine was 86 +/- 13 minutes. The mean peak serum concentration of tetracycline was 3.6 microgram/ml +/- 0.9 microgram/ml (range, 1.0 microgram/ml to 5.0 micrograms/ml), and the mean time to peak serum concentration of tetracycline was 96 +/- 16 minutes. Therapeutic serum concentrations of lidocaine were found in four of the seven patients and therapeutic serum levels of tetracycline in four of five patients. With systemic absorption of lidocaine and tetracycline following intrapleural instillation, patients are at risk for potential toxic effects. If lidocaine is used in a dosage of less than 3 mg/kg, toxic levels of the drug are unlikely to occur. Furthermore, use of tetracycline or lidocaine in pleurodesis is contraindicated in patients with known sensitivity to the drugs.

Female↗
PubMed1988

Pleural fluid pH in malignant effusions. Diagnostic, prognostic, and therapeutic implications.

STUDY OBJECTIVE: To determine whether the measurement of pleural fluid pH in malignant effusions has diagnostic use, predicts survival, and has therapeutic implications. DESIGN: A prospective comparison of cytologic examinations and pleural biopsy results, survival, and response to chemical pleurodesis with tetracycline in patients with normal-pH (7.30 or greater) and low-pH (less than 7.30) malignant pleural effusions. SETTING: Academic medical center, university referral hospital, city hospital, and Veterans Administration hospital. PATIENTS: Sixty patients with malignant pleural effusions, proven at either initial thoracentesis by cytologic examination or within 4 months of initial thoracentesis by repeat thoracentesis, thoracotomy, or autopsy, were followed until death. INTERVENTION: Twenty-one patients, 12 with normal pleural fluid pH and 9 with low pleural fluid pH, were treated with tube thoracostomy and intrapleural tetracycline for symptomatic, recurrent pleural effusions. MAIN RESULTS: The 20 patients with low-pH malignant effusions had a significantly greater positivity on initial pleural fluid cytologic evaluation, a shorter mean survival, and a poorer response to tetracycline pleurodesis compared with 40 patients with normal-pH malignant effusions. CONCLUSIONS: Determination of pleural fluid pH in malignant effusions provides a rational approach to further diagnostic testing, prognostic information, and a rationale for palliative treatment.

Cytodiagnosis↗
PubMed1988

Pleural effusions in the atypical pneumonias.

Patients with atypical pneumonias, whether caused by bacterial, fungi, or viruses are associated with pleural effusions. The effusions generally are small and ipsilateral to the parenchymal infiltrate. Usually, the pleural fluid is a serous exudate with a predominance of mononuclear cells. The pleural fluid glucose and, presumably, the pleural fluid pH are not low. The etiologic organism has been isolated from pleural fluid but usually is not necessary to establish the diagnosis. Pleural biopsy is not helpful in diagnosis with the exception of acute coccidioidal pneumonia and effusion. Pleural effusions in the atypical pneumonias are more common than generally appreciated, rarely provide a definitive diagnosis, and resolve spontaneously with treatment of the pneumonia without pleural space manipulation. Furthermore, evidence of pleural effusion is a marker of the atypical pneumonias and directs the clinician along the appropriate diagnostic pathway based on the clinical presentation.

Anthrax↗
PubMed1988

The impact of respiratory failure on the diagnosis of tuberculosis.

Six patients with hypoxic respiratory failure (arterial PO2/alveolar PO2 less than 0.50) resulting from active tuberculosis were evaluated to assess the impact of respiratory failure on the diagnosis of the underlying tuberculosis. All patients demonstrated anemia (hematocrit [mean +/- SEM], 0.29 +/- 0.01 [29.0% +/- 1.0%]) and hypoalbuminemia (serum albumin, 22 +/- 2 g/L [2.2 +/- 0.2 g/dL]) and noted an illness longer than one week. Findings on chest roentgenograms varied from a miliary pattern, misinterpreted as congestive heart failure, to cavitary and noncavitary alveolar infiltrates, misdiagnosed as bacterial pneumonia. Tuberculosis was not considered as a diagnostic possibility on admission in any patient. The mean time from admission until consideration of tuberculosis was 4.7 +/- 1.0 days and the time to diagnosis was 7.2 +/- 1.7 days. In contrast, tuberculosis was considered on admission in 12 patients presenting with undiagnosed active tuberculosis without respiratory failure. We conclude that respiratory failure delays the diagnosis of active tuberculosis by suggesting nontuberculous pneumonia.

Adult↗
PubMed1987

Protected transbronchial needle aspiration and protected specimen brush in the diagnosis of pneumonia.

Protected transbronchial needle aspiration (PTBNA) of pneumonic lung theoretically could bypass dislodged upper respiratory tract flora, a potential source of contamination of protected specimen brush (PSB) cultures. To evaluate the usefulness of PSB and PTBNA in establishing the etiology of pneumonia, we prospectively studied 20 patients with acute bacterial pneumonia not receiving antibiotics. After informed consent, patients had fiberoptic bronchoscopy under fluoroscopy to localize the pneumonia, and specimens were obtained by the PSB. The protective plug of a specially devised needle for PTBNA was pneumatically dislodged and aspiration was performed within the infiltrate under fluoroscopy. Quantitative cultures were plated immediately for aerobes, anaerobes, and Legionella. Greater than 4 X 10(3) organisms/brush or 1 X 10(4) organisms/ml needle aspirate were considered to be consistent with infection. The results using PSB and PTBNA were compared in 15 of 20 patients in whom a definitive diagnosis (positive blood or pleural fluid culture) or presumptive diagnosis (expectorated sputum culture, clinical characteristics, and response to specific therapy) was established. The PSB and PTBNA cultures on uninfected control subjects (n = 5) being bronchoscoped for other reasons were negative. The PSB and PTBNA were each diagnostic in 2 of the 5 patients with definitive diagnoses. In the group with a presumptive diagnosis (n = 10), PSB was diagnostic in 7 of 10 and PTBNA in 9 of 10. The overall (definitive plus presumptive) diagnostic yield was 60% for PSB and 73% for PTBNA. Multiple organisms were isolated in high concentrations in 53% of the patients. The most common organisms recovered in addition to the primary pathogen was alpha hemolytic streptococci.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Thoracocentesis. Clinical value, complications, technical problems, and patient experience.

A prospective study of 129 consecutive thoracocentesis in 86 patients at a university medical center evaluated the clinical value, complications, and patient experience with thoracocentesis. Pleural fluid analysis in conjunction with the clinical presentation placed 78 pleural fluids into diagnostic categories: definitive 14 (18 percent), presumptive 44 (56 percent), and nondiagnostic 20 (26 percent). Fourteen of 78 (18 percent) of the nondiagnostic fluids were useful, while only six (8 percent) were not useful clinically; therefore, 92 percent of thoracocentesis provided clinically useful information. Using sequential data analysis, initial diagnostic categorizations of eight of 78 patients were upgraded from presumptive or nondiagnostic to definitive based on data available 24 hours following thoracocentesis. Thus, 70 patients were categorized based on the pleural fluid data obtained within the first 24 hours of thoracocentesis. Thirty-four objective complications occurred in 26 of 129 (20 percent) thoracocentesis. The most common complications were pneumothorax, 15 of 129 (12 percent), and cough, 12 of 129 (9 percent). Sixty-five subjective complications occurred in 56 of 123 (46 percent) thoracocentesis. Anxiety, 26 of 123 (21 percent), and site pain, 24 of 123 (20 percent), were the most common subjective complications noted. Thirty technical problems occurred in 129 (23 percent) thoracocentesis with blood contamination, 14 of 129 (11 percent), and dry tap, nine of 129 (7 percent), being the most common. We conclude that diagnostic thoracocentesis is a clinically valuable procedure if used in conjunction with the patient presentation with an understanding of its limitations for providing a specific etiologic diagnosis. When performed by physicians in training, the number of complications are substantial and the operator often underestimates the degree of patient discomfort. Awareness of the clinical value and complications of thoracocentesis should lead to improved use and safety of this procedure.

Adult↗
PubMed1987

Pulmonary hemorrhage and air embolism complicating transbronchial biopsy in pulmonary amyloidosis.

We describe a fatal complication of transbronchial biopsy in a patient with pulmonary parenchymal amyloidosis. Hemorrhage after biopsy required intubation and positive-pressure ventilation that resulted in massive arterial air embolism. Postmortem findings suggested that the bleeding and air embolism were related to persistent patency of biopsied blood vessels infiltrated with amyloid. Patients with pulmonary amyloidosis may be at increased risk of major complications after transbronchial biopsy.

Aged↗