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Biomedical subjects

Armin Ernst

Publications and source records attributed to Armin Ernst.

52 records · Page 3Linked to original sources
PubMed2003

Percutaneous tracheostomy--special considerations.

Percutaneous tracheostomy is safe and highly effective in well-trained hands in establishing a long-term artificial airway. Most alleged contraindications and some suggestions on how the procedures should be performed likely stem from early trials when only "perfect candidates" were chosen. Most of those contraindications should not be viewed as prohibitions, but as suggestions related to the skill level and training of the operator. We have used this technique in many situations where the small incision and tamponading effect of the tracheostomy tube has been quite beneficial, in selected patients with coagulapathies and severe venous congestion from superior cava syndromes as well as thyroid cancers, and in whom operative approaches would have been difficult. Knowing one's level of expertise and comfort in choosing and rejecting patients and procedures accordingly is the key to keeping PT a procedure with an excellent safety record. As the experience with PT grows, more and more perceived contraindications will disappear. Studies will address the role of PT in children and as a means of establishing emergent airway access. Also, the exact coagulation limits will need to be established. Few contraindications will most likely remain absolute, such as active infections over the proposed entry site, uncontrollable bleeding disorders and excessive ventilatory and oxygenation requirements. In our institution, taking into account these absolute contraindications, fewer than 5% of patients in need of a tracheostomy in the intensive care unit will undergo a primary open procedure.

Bronchoscopy↗
PubMed2003

Endobronchial ultrasound reliably differentiates between airway infiltration and compression by tumor.

OBJECTIVE: A frequent problem in patients with intrathoracic malignancies neighboring central airways is the question of whether the airway wall is infiltrated by the tumor or if it is merely compressed. This distinction can often not be made with certainty with the help of chest CT alone, but frequently necessitates surgical biopsy or exploration. We prospectively studied the utility of endobronchial ultrasound (EBUS) in this clinical circumstance. METHODS AND PATIENTS: Between May 1999 and July 2000, 131 consecutive patients with central thoracic malignancies potentially involving the airways were enrolled into the study. Patients underwent chest CT followed by standard bronchoscopy together with EBUS and subsequent surgical evaluation. The bronchoscopists did not know the radiologist's interpretation of the chest CT before performing EBUS. The ability of chest CT and EBUS to distinguish between compression and infiltration was measured against the histologic results. RESULTS: One hundred five patients completed the trial by undergoing surgery. In 81 patients (77%), the CT scan was read as consistent with tumor invasion. EBUS only showed invasion in 49 cases (47%). Histology after surgery revealed a specificity of 100%, a sensitivity of 89%, and an accuracy of 94% for EBUS. Chest CT was far inferior, with a specificity of 28%, a sensitivity of 75%, and an accuracy of 51%. CONCLUSION: We conclude that EBUS is a highly accurate diagnostic tool and superior to chest CT in evaluating the question of airway involvement by central intrathoracic tumors. In the hands of experienced endoscopists, EBUS may become the procedure of choice for this question.

Adult↗
PubMed2003

Ultrasound-guided transbronchial needle aspiration: an experience in 242 patients.

STUDY OBJECTIVES: Conventional transbronchial needle aspiration (TBNA) is a valuable procedure but remains underutilized. Recently, imaging guidance such as CT fluoroscopy has created considerable interest. As CT fluoroscopy is cumbersome and exposes patients and staff to radiation, we have examined the feasibility of endobronchial ultrasound (EBUS) in providing imaging support for TBNA. DESIGN: Prospective consecutive patient enrollment. SETTING: University-related tertiary referral centers for pulmonary diseases. RESULTS: From January 1999 to January 2000, 242 consecutive patients were entered into this prospective study (82 women and 160 men; mean age, 60.0 years). Indications for TBNA were diagnosis of enlarged lymph nodes and cancer staging. The average lymph node size was 1.7 cm (SD, 0.47; range, 0.8 to 4.3 cm). Target lymph nodes were visualized with EBUS, followed by TBNA in standard fashion. All targets could be visualized with EBUS. In 207 patients, the lymph nodes were successfully sampled (86%). This was independent of lymph node size and location. A firm diagnosis or cancer stage could be obtained in 172 patients (72%). There were no complications associated with the use of EBUS. CONCLUSION: EBUS is simply performed and if used for TBNA guidance affords an excellent yield independent of lymph node location. Randomized trials comparing standard TBNA and imaging-guided TBNA by CT fluoroscopy and EBUS are indicated.

Adult↗
PubMed2003

The role of bronchoalveolar lavage in the immunocompromised host.

Bronchoscopy with bronchoalveolar lavage (BAL) is a frequently performed, minimally invasive endoscopic examination in patients with unclear infiltrates or pulmonary infections. It can be performed safely in patients with compromised immune systems of different etiologies. This article summarizes the experience with and efficacy of BAL in different disease states in this clinical circumstance. Because human immunodeficiency virus (HIV)-related diseases and acquired immune deficiency syndrome (AIDS) patients show different characteristics when compared with patients with other reasons for immunosuppression, they are discussed separately. Clinical algorithms are presented.

AIDS-Related Opportunistic Infections↗
PubMed2002

Repeat bedside percutaneous dilational tracheostomy is a safe procedure.

OBJECTIVE: Previous tracheostomy has been considered a relative contraindication for percutaneous dilational tracheostomy. The objective of this study was to assess the safety of percutaneous dilational tracheostomy in critically ill patients with a history of previous tracheostomy. DESIGN: Retrospective, single-center case series of all consecutive patients requiring repeat tracheostomy for continued mechanical ventilatory support. SETTING: Intensive care unit of a tertiary-care referral center. SUBJECTS: Fourteen patients (eight female, six male) with a median age of 70 yrs (range, 33-94). All patients had previously undergone tracheostomy. INTERVENTION: Bedside percutaneous dilational tracheostomy. MEASUREMENT AND MAIN RESULTS: Subjects' previous tracheostomies dated back between 10 days and 8 yrs. Present intubation time before percutaneous dilational tracheostomy varied between 4 and 30 days. Bedside percutaneous dilational tracheostomy was performed successfully in all 14 patients by trained pulmonologists and surgeons. Eleven patients received an 8-mm and three received a 7-mm tracheostomy tube. There were no significant periprocedural complications, and no patient required surgical revision. The only postprocedural complication was accidental decannulation in one patient, which was managed with repeat percutaneous dilational tracheostomy. CONCLUSIONS: Trained physicians can safely perform bedside percutaneous dilational tracheostomy after previous tracheostomy. Percutaneous dilational tracheostomy offers an alternative to surgical tracheostomy in this particular patient population and should not be considered contraindicated.

Adult↗
PubMed2002

Recent advances in central airway imaging.

The purpose of this article is to familiarize chest physicians with recent advances in airway imaging, with an emphasis on the emerging role of two-dimensional reformatted and three-dimensional CT reconstructed images in the assessment of central airway disorders.

Bronchi↗
PubMed2002

Aspirin does not increase bleeding complications after transbronchial biopsy.

STUDY OBJECTIVES: The present study was performed to determine whether the risk of bleeding after transbronchial lung biopsy is increased in patients taking aspirin. DESIGN: Prospective cohort study. PATIENTS AND INTERVENTIONS: After excluding patients with other coagulation problems, 1,217 patients who had undergone transbronchial lung biopsy during a prospective 1.5-year study period were included in this study. The use of aspirin was not discontinued before the procedure. Two hundred eighty-five patients (23%) had consumed aspirin within 24 h of the procedure, and most of them (82%) used aspirin on a daily basis. Transbronchial biopsies were performed, and the bleeding incidence was compared between the groups. RESULTS: A total of 57 patients (4.7%) experienced procedure-related bleeding. Minor bleeding occurred in 5 of 285 patients (1.8%) taking aspirin and in 27 of 932 control patients (2.9%; not significant). Moderate bleeding was seen in 3 of 285 patients (1.1%) in the aspirin group and in 13 of 932 patients (1.4%) in the control group (not significant). Major bleeding occurred in only 9 patients, 2 of 285 (0.9%) in the aspirin group and 7 of 932 (0.8%) in the control group (not significant). All bleeding was controlled by endoscopic means, and there were no fatalities and no need for blood transfusions. CONCLUSIONS: We conclude that the risk of severe bleeding after transbronchial lung biopsy is small (ie, < 1%) and that the use of aspirin is not associated with any increased risk of bleeding.

Adult↗
PubMed2002

A novel instrument for the evaluation of the pleural space: an experience in 34 patients.

STUDY OBJECTIVES: To test a novel semirigid pleuroscope to be used by pulmonologists for the diagnosis and treatment of pleural diseases. DESIGN: Prospective study. SETTING: Three tertiary referral centers for pulmonary diseases. PATIENTS: Thirty-four patients who were referred for medical thoracoscopy between September 2000 and April 2001. MEASUREMENTS AND RESULTS: Thirty-six procedures were performed. The most common indications were for pleurodesis of a malignant pleural effusion (53%) or for evaluation of an exudative effusion of unknown etiology (44%). All operators found the instrument easy to use. In all but one case, the images were thought to be adequate, despite the presence of adhesions in 12 patients and loculations in 8 patients. Pleural biopsies were performed in 13 patients, and talc pleurodesis procedures were performed in 25 patients. Mean (+/- SD) duration of chest tube drainage was 2.9 +/- 1.8 days postprocedure. There were no complications. CONCLUSIONS: The prototype semirigid pleuroscope is a useful instrument in the diagnosis and management of pleural diseases. It is similar in design to a standard flexible bronchoscope, so the skills involved in operating the instrument should already be familiar to the practicing pulmonologist. It is compatible with existing video processors and light sources, so little additional equipment must be added to the endoscopy suite. The semirigid pleuroscope may allow for an increase in the performance of medical thoracoscopy by pulmonologists.

Equipment Design↗
PubMedDate not supplied

Ultrasound guidance for medical thoracoscopy: a novel approach.

BACKGROUND: Commonly, a pneumothorax is induced before medical thoracoscopy to facilitate safe entry into the pleural space. OBJECTIVE: Evaluate the use of transthoracic ultrasound to locate a safe entry site for trocar placement during medical thoracoscopy without induction of a preprocedure pneumothorax. METHOD: The study was designed as a prospective cohort study, performed in the setting of a tertiary care hospital with an active interventional pulmonology program. It included 20 consecutive patients referred for medical thoracoscopy. RESULTS: Ultrasound identified entry sites in all 20 patients. All sites were successfully used, despite the presence of adhesions in 3 patients. There were no complications. CONCLUSIONS: Ultrasound could safely and reliably identify entry sites for trocar placement during medical thoracoscopy, even in patients with pleural adhesions. The use of ultrasound may replace the practice of pneumothorax induction before medical thoracoscopy.

Aged↗
PubMedDate not supplied

State-of-the-art imaging of the central airways.

Recent technological advances in CT imaging have revolutionized non-invasive imaging of the central airways. It is now possible to image the entire central airways in a few seconds and to create elegant three-dimensional reconstructions of the airways in a few minutes. The fast speed of CT scanning now allows for a dynamic assessment of the central airways, expanding the ability to non-invasively detect functional abnormalities such as tracheobronchomalacia. The purpose of this article is to familiarize clinicians with recent advances in airway imaging. A special emphasis is placed upon advanced CT reconstruction methods and their potential contributions to the evaluation of a variety of airway disorders.

Bronchoscopy↗
PubMedDate not supplied

Electromagnetic navigation during flexible bronchoscopy.

BACKGROUND: Flexible bronchoscopy is routinely utilized in the diagnosis and treatment of various lung diseases. Nondiagnostic bronchoscopy leads to more invasive interventions, such as transthoracic needle aspiration, mediastinoscopy or even thoracotomy. Electromagnetic navigation is a novel technology that facilitates approaching peripheral lung lesions, which are difficult to sample by conventional means. The navigation system involves creating an electromagnetic field around the chest and localizing an endoscopic tool using a microsensor overlaid upon previously acquired CT images. OBJECTIVES: To determine the practicality, accuracy and safety of real-time electromagnetic navigation, coupled with previously acquired 3D CT images, in locating artificially created peripheral lung lesions in a swine model. METHODS: Peripheral lung lesions were created in four swine models by insertion of a metal tube (1 x 10 mm) via a transthoracic approach. An electromagnetic field was created by placing the animal on an electromagnetic location board. A position sensor incorporated into the distal tip of a dedicated tool was used to navigate to the various target lesions. Information gathered in real time during bronchoscopy was presented on a monitor simultaneously by displaying previously acquired CT images. Upon reaching the target lesion, biopsies were performed and the functionality and safety of the superDimension/Bronchus System was observed and documented. RESULTS: The registration accuracy expressed by the fiducial target registration error, expressing both the registration quality and the stability of fiducial (registration) points, was 4.5 mm on average. No adverse effects, such as pneumothorax or internal bleeding, were encountered in any of the animals in this study. CONCLUSIONS: Real-time electromagnetic positioning technology coupled with previously acquired CT images is an accurate technology added to standard bronchoscopy to assist in reaching peripheral lung lesions and performing biopsies.

Animals↗
PubMedDate not supplied

Contraindications and safety of transbronchial lung biopsy via flexible bronchoscopy. A survey of pulmonologists and review of the literature.

BACKGROUND: Transbronchial lung biopsy (TBLB) via flexible bronchoscopy is a common procedure performed by pulmonologists. Limited scientific data exist concerning the risk of this procedure in patients with conditions that may adversely affect the rate of procedural complications. OBJECTIVES: To evaluate the current practice pattern and attitude of pulmonologists toward the performance of TBLB in the presence of high-risk conditions. METHODS: A survey was constructed and distributed at the American College of Chest Physicians annual meeting, held in Philadelphia, USA, in November of 2001. RESULTS: A total of 227 surveys were distributed with a return of 158 (69.6%). Anticoagulation medications are temporarily held prior to TBLB by the majority of our survey respondents (98.7% for intravenous heparin, 90.5% for warfarin, and 87.3% for low-molecular-weight heparin). Medications with effect on platelet function are held by fewer pulmonologists. There is a wide variation in the pulmonologists' perception of the risk of performing TBLB when certain medical conditions coexist: pulmonary hypertension [absolute contraindication (AC), 28.7%; relative contraindication (RC) 58.6%], superior vena cava syndrome (AC 19.6%, RC 51%), mechanical ventilation (AC 17.8%, RC 58.6%) and lung cavity/abscess (AC 7%, RC 44.9%). A significant percentage of pulmonologists (55%) do not regard an elevated serum creatinine at any level as AC to TBLB. Thirty-eight percent of the survey participants administer desmopressin prior to TBLB in uremic patients to prevent excessive bleeding. CONCLUSIONS: Prior to performing bronchoscopic TBLB, the majority of pulmonologists temporarily holds anticoagulation medications. However, there is a lack of agreement in relation to perceived contraindications and safety of TBLB.

Bronchoscopy↗
PubMedDate not supplied

Role of the interventional pulmonologist in the intensive care unit.

Interventional pulmonology is a new field within the pulmonary and critical care medicine specialty with a focus on invasive diagnostic and therapeutic modalities in airway and pleural disorders. The interventional pulmonologist is highly qualified to take a prominent role in the intensive care unit in a consultative fashion to provide assistance with pleural procedures, establishment and care of artificial airways, and management of patients with respiratory failure attributable to structural central airway disorders. The presence of a dedicated operator with advanced skills facilitates access to specialized procedures in an expeditious and safe manner. Clear communication between the interventional pulmonologist and intensivist is vital to ensure a collaborative effort that delivers optimal patient care.

Airway Obstruction↗