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Biomedical subjects

Andreas H Diacon

Publications and source records attributed to Andreas H Diacon.

6 recordsLinked to original sources
PubMed2003

Accuracy of pleural puncture sites: a prospective comparison of clinical examination with ultrasound.

STUDY OBJECTIVE: To assess the value of chest ultrasonography vs clinical examination for planning of diagnostic pleurocentesis (DPC). DESIGN: Prospective comparative study. SETTING: Pulmonary unit of a tertiary teaching hospital. PATIENTS AND PARTICIPANTS: Sixty-seven consecutive patients referred to 30 physicians of varying degrees of experience for DPC. INTERVENTIONS: Based on clinical data and examination, physicians determined whether and where a DPC should be performed. Selected puncture sites were evaluated with ultrasound and considered accurate when > or = 10 mm fluid perpendicular to the skin were present. MEASUREMENTS AND RESULTS: In 172 of 255 cases (67%), a puncture site was proposed. Twenty-five sites (15%) were found to be inaccurate on ultrasound examination, and a different, accurate site was established in 20 of these cases. Physicians were unable to locate a puncture site in 83 cases (33%). Among these, ultrasound demonstrated an accurate site in 45 cases (54%), while a safe tap was truly impossible in 38 cases (46%). Overall, ultrasound prevented possible accidental organ puncture in 10% of all cases and increased the rate of accurate sites by 26%. The sensitivity and specificity for identifying a proper puncture site with clinical examination compared to ultrasound as the "gold standard" were 76.6% and 60.3% (positive and negative predictive values, 85.5% and 45.8%, respectively). Risk factors associated with inaccurate clinical site selection were as follows: small effusion (p < 0.001), evidence of fluid loculation on chest radiography (p = 0.01; relative risk, 7.8; 95% confidence interval, 1.9 to 32.9), and sharp costodiaphragmatic angle on chest radiography (p < 0.001; relative risk, 7.0; 95% confidence interval, 2.3 to 15.2). Experienced physicians did not perform better than physicians in training. CONCLUSIONS: Puncture site selection with bedside ultrasonography increases the yield of and potentially reduces complication rate in DPC. Physician experience does not predict the accuracy of selected puncture sites.

Adult↗
PubMed2003

Paraneoplastic bilateral proptosis in a case of non-small cell lung cancer.

We report the case of a 51-year-old woman with a large cell bronchial carcinoma with neuroendocrine differentiation (T3N0M0, stage IIB) and bilateral exophthalmos. A CT of the orbitae was compatible with Graves ophthalmopathy, but neither abnormalities in thyroid function nor thyroid antibodies could be found. The proptosis normalized 10 days after tumor resection. We conclude that the most likely cause of the reversible proptosis in this patient is paraneoplastic, a condition not previously described in the English-language literature.

Carcinoma, Large Cell↗
PubMed2003

Use of an ultrathin bronchoscope in the assessment of central airway obstruction.

STUDY OBJECTIVE: To assess the utility of an ultrathin bronchoscope (UB) in the assessment of central airway obstruction (CAO). DESIGN: Prospective evaluation SETTING: Tygerberg Hospital, a tertiary teaching hospital. PATIENTS: Consecutive patients referred to the Lung Unit with CAO. INTERVENTIONS: Fiberoptic bronchoscopy (FOB) was performed with a prototype UB (Olympus BF XP40; Olympus Europe; Hamburg, Germany; outer diameter, 2.8 mm; working channel, 1.2 mm). The UB was used whenever a standard bronchoscope (SB) could not pass the obstruction or could not be tolerated by the patient. MEASUREMENTS AND RESULTS: Data relating to indication and performance of FOB, patient demographics, utility in establishing a diagnosis, and planning definitive management were documented. Twenty-four patients (17 men; mean age, 46 years) were studied. Twelve patients (50%) had malignant CAO, 8 patients (33%) had benign tracheal stenosis, 3 patients (12.5%) had stent occlusion, and 1 patient (4%) had bilateral vocal cord paralysis. In 42% of patients, an initial attempt at passing the obstruction with an SB had failed. Vocal cords or trachea were involved in 62% of patients. The mean luminal occlusion was 84% of the total airway lumen (range, 50 to 100%). One complication (desaturation) led to early termination of FOB. In all but three patients with complete obstruction, the UB was able to pass the CAO and allowed assessment of the obstruction and the distal airways (87%). CONCLUSION: UB-FOB was useful and safe in the assessment of patients with CAO from both benign and malignant disease. It aided in establishing a diagnosis and/or planning of definitive management in all patients examined.

Adult↗
PubMed2002

Functional evaluation before lung resection.

Advances in operative technique and perioperative care have reduced surgical morbidity and mortality considerably after pulmonary resections. Various single and combined parameters of functional operability have been proposed to assess the surgical risk. Patients with normal or only slightly impaired pulmonary function (FEV1 and DLCO > or = 80% predicted) and no cardiovascular risk factors can undergo pulmonary resections up to a pneumonectomy without further investigation. For others, exercise testing, pulmonary split-function studies, or a combination of these methods are recommended. Cardiopulmonary exercise testing, most frequently performed as a symptom-limited test with the measurement of VO2max, assesses the pulmonary and cardiovascular reserves. A VO2max of less than 10 mL/kg/minute generally is considered prohibitive for any resection, a value of greater than 20 mL/kg/minute or greater than 75% predicted normal, safe for major resections. Split-function studies are radionuclide-based estimations of the ppo values of various parameters. The currently used ppo parameters are FEV1-ppo, DLCO-ppo, and VO2max-ppo. Suggested cutoff values for safe resection are: FEV1-ppo and DLCO-ppo 40% or greater than predicted, and V(r)O2max-ppo 35% or greater than predicted, combined with an absolute value of greater than or equal to 10 mL/kg/minute. The lowest acceptable ppo values remain to be confirmed by additional prospective studies. Resections involving not more than one lobe usually lead to an early functional deficit followed by recovery. The permanent loss in pulmonary function is small (approximately 10%) and exercise capacity is reduced only slightly or not at all. Pneumonectomy leads to an early permanent loss of about 33% in pulmonary function and approximately 20% in exercise capacity. Pulmonary function tests alone therefore overestimate the functional loss after lung resection.

Algorithms↗