Search PubMed⌕ Search

Biomedical subjects

H G Colt

Publications and source records attributed to H G Colt.

At least 37 records · Page 2Linked to original sources
PubMed1995

Comparison of wedge to forceps videothoracoscopic lung biopsy. Gross and histologic findings.

BACKGROUND: The decreased morbidity and rapid recovery after thoracoscopic lung biopsy compared with open lung biopsy by thoracotomy is increasingly recognized, as is the ability to obtain satisfactory diagnostic material thoracoscopically. To our knowledge, however, there has been no systematic comparison of specimen quality using different thoracoscopic biopsy techniques. The purpose of this study was to compare histologic features of lung parenchyma obtained by videothoracoscopic forceps and wedge biopsy techniques. METHODS: Five adult swine were anesthetized, intubated, and ventilated. Sequential left and right videothoracoscopies were performed to obtain biopsy specimens of lung parenchyma using 5-mm endoscopic cupped forceps. Specimens were obtained from fully inflated lung and from partially atelectatic (deflated) lung. Electrosurgery was applied during forceps biopsy for airleak closure. Limited wedge biopsy specimens were obtained using an endoscopic stapler. One hundred thirteen forceps biopsy specimens (55 inflated, 58 deflated) and 24 sections from 8 wedge biopsy specimens were examined. Specimens were assessed for overall histologic quality and ease of microscopic interpretation. Specific histologic features were then evaluated including presence of artifact, congestion and hemorrhage, degree of alveolar inflation, and number of bronchioles and vessels per cross-sectional area. Whole lungs from two animals were examined for extent and depth of lung injury at the areas of biopsy. RESULTS: No major differences in overall microscopic specimen quality were detected among the different techniques nor were significant differences noted between lung inflated and lung deflated forceps biopsy technique. Wedge sections contained more vessels per unit area (p < 0.001), perhaps reflecting the more peripheral nature of forceps biopsy. Small amounts of thermal or crush artifact were noted on the surface of forceps biopsy specimens, but did not affect overall specimen quality. CONCLUSIONS: Multiple 5-mm forceps biopsy specimens were of comparable quality to single wedge biopsy specimens obtained by endoscopic stapling. Although greater numbers of vessels were present in endoscopic stapled wedge biopsy specimens, multiple forceps biopsy specimens in fact, contain amply sufficient vessels for histologic analysis.

Animals↗
PubMed1995

Thoracoscopy. A prospective study of safety and outcome.

OBJECTIVE: To assess a standard classification of adverse events and evaluate the safety and long-term outcome of thoracoscopy in patients with pleural disease. DESIGN: Prospective nonrandomized cohort study. SETTING: The Pulmonary Special Procedures and Nd:YAG Laser Unit of the University of California San Diego Medical Center, San Diego. PATIENTS: Fifty consecutive patients undergoing thoracoscopy for diagnosis of pleural effusion or thickening, pleurodesis, or empyema drainage. INTERVENTION: A list of major and minor adverse events that could be temporally related to thoracoscopy performed for diagnosis or treatment of pleural processes was established before beginning this prospective study. Procedures were performed using multiple point-of-entry techniques and either local or general anesthesia. Most procedures were performed in the operating room using double-lumen intubation. Patients were seen daily during hospitalization and at least 7, 30, and 90 days after thoracoscopy. Long-term follow-up data were obtained by telephone calls, clinical visits, or medical chart reviews or all of these, until 12 months after procedures. MEASUREMENTS: Occurrence of major and minor adverse events possibly related to thoracoscopy was recorded prospectively. Demographic and clinical data, as well as efficacy and outcome after thoracoscopy, were also noted. RESULTS: Fifty-two procedures were performed in 50 patients. Median age was 60 years (range, 18 to 88 years). Thoracoscopy provided a diagnosis in 93% of patients with pleural disease of unclear origin. Pleurodesis by thoracoscopic talc insufflation was successful in 95% of cases and in 91% of patients with malignant pleural effusions still available for evaluation and follow-up examination 3 months after pleurodesis. Thoracoscopic drainage of empyema was successful in six of seven patients and led to referral for open decortication in one. There were no procedure-related deaths or intraoperative accidents. Open-chest surgery intervention was never required. Only 1 major adverse event occurred: a patient with scleroderma and trapped lung had recurrent pleural effusion requiring chest tube drainage 1 week after hospital discharge. Minor adverse events, however, were noted in ten instances (19%). These included fever after talc pleurodesis, asymptomatic pneumothorax after chest tube removal, and minor would infection in a patient with empyema. CONCLUSION: Using the proposed classification of major and minor adverse events, prospective evaluation demonstrated the safety, diagnostic utility, and long-term efficacy of thoracoscopy performed for diagnosis and management of pleural processes. Potential dangers, however, of thoracoscopy are acknowledged, and limitations of the procedure are addressed.

Adolescent↗
PubMed1995

AIDS-related spontaneous pneumothorax. Risk factors and treatment.

OBJECTIVE: To define risk factors and optimum therapy for AIDS-related spontaneous pneumothorax (PTX). DESIGN: Case-control study. SETTING: Tertiary care center. PATIENTS: Thirty-five patients with AIDS who developed spontaneous PTX between January 1, 1988 and December 31, 1991, of whom 27 (77.1%) did so in the setting of Pneumocystis carinii pneumonia (PCP). Forty-one patients who were diagnosed as having PCP and did not develop PTX served as the control group. RESULTS: Using logistic regression, a history of cigarette smoking, aerosolized pentamidine treatment, and the observation of pneumatoceles by chest radiography were associated with an increased risk of PTX. Although not associated with an increased risk of occurrence of PTX, the use of systemic corticosteroids for PCP treatment was associated with a longer requirement for chest tube drainage. Although chest tube drainage alone was often successful, chemical and surgical pleurodesis was often effective in treating prolonged air leaks and was associated with a lower incidence of recurrent PTX, although this difference did not achieve statistical significance (p = 0.07). CONCLUSIONS: Patients at high risk of developing AIDS-related spontaneous PTX can be identified. Systemic corticosteroids may increase the risk of morbidity from AIDS-related PTX. Chemical and surgical pleurodesis may be of value in short-term treatment and in reducing the risk of recurrence.

AIDS-Related Opportunistic Infections↗
PubMed1995

Airway stents. Present and future.

Tracheobronchial stent insertion is a relatively new technique used to palliate or cure central airways obstruction. When performed by experienced thoracic endoscopists, this procedure is both safe and effective, even if complications of indwelling stents may require repeat endoscopic intervention. Although proven clinically beneficial to many patients, airway prostheses have not yet been the subject of large comparative case studies or randomized controlled investigations. Reports are often experiential and anecdotal. Further research is needed to determine the effects of stenting on survival in patients with malignant airway disease and its degree of success in patients with benign airway strictures. Only then will airway stents truly deserve their place alongside other therapies for tracheobronchial obstruction.

Bronchial Diseases↗
PubMed1995

Thoracoscopic management of malignant pleural effusions.

Thoracoscopy has been around for decades, advocated by some, but until recently, ignored by many. Not surprisingly, its diagnostic and therapeutic efficacy in patients with suspected or proven malignant pleural effusions has withstood the test of time. Today, the potential benefits of thoracoscopy must be weighed against its cost in patients with limited life expectancy. Although diagnostic thoracoscopy requires only overnight hospitalization, pleurodesis imposes a longer hospital stay. The discomfort of an indwelling chest tube, the need for hospitalization, and the financial burden of thoracoscopic procedures compared with less-invasive means of pleural investigation and pleurodesis must be taken into account on an individual basis. Thoracoscopy should not be performed for the sake of intervention. Its indications and all diagnostic or therapeutic alternatives should always be carefully examined. Its role, however, in the diagnosis and treatment of patients with malignant pleural effusions is undeniable. The diagnostic accuracy of thoracoscopic pleural biopsy is excellent. Several studies demonstrate that thoracoscopic talc pleurodesis is more frequently successful than other methods of pleurodesis. As a staging procedure, thoracoscopy helps determine extent of disease, and possibly, prognosis in patients with metastatic pleural carcinomatosis, lung cancer, and malignant mesothelioma. As this procedure is increasingly rediscovered by our medical and surgical communities, greater clinical and experimental investigation aimed at establishing successful management strategies in patients with malignant pleural effusions will hopefully occur.

Biopsy↗
PubMed1994

"Patient-like" nude mouse metastatic model of advanced human pleural cancer.

Pleural cancer in humans is a frequently occurring tumor. Recently, clinical trials have suggested that chemotherapy and immunotherapy administered intrapleurally may elicit responses in early-stage diseases. However, at radiological and pleural endoscopic evaluation, most of the patients are found to have a visceral pleural involvement that is generally refractory to therapy and leads to a poor prognosis. The goal of this study was to construct a nude mouse model of human parietal- and visceral-pleural cancer that could reflect the clinical picture for this disease. The model could then be useful for drug discovery for pleural cancer. A well-differentiated human lung adenocarcinoma was used as intact tissue for implantation. Ten mice underwent parietal-pleural implantation and ten mice visceral-pleural implantation via a novel thoracotomy procedure we have developed. Symptoms of tumor growth were determined from weight loss, respiratory distress, or debilitation. Actual tumor growth and spread were measured at autopsy. The mouse survival curves of each group were estimated by the Kaplan-Meier method and the difference of the median survival times was assessed by the Log-rank test. The slopes of mean-mouse weight curves were compared using a standard two-sample t-test. A 100% take rate was achieved in constructing the pleural cancer models. Tumor growth was initially assessed by symptomatology and survival: the median survival time was, respectively, 27.9 days and 31 days for visceral-pleural and parietal-pleural implanted groups (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1994

Comparison of SPECT lung perfusion with transbronchial lung biopsy after lung transplantation.

The objective of this study was to evaluate the potential role for single photon-emission computed tomography (SPECT) using technetium 99m-macroaggregated albumin for diagnosing rejection in lung transplant patients. SPECT results were compared with those obtained from transbronchial biopsy (TBB) in patients undergoing bronchoscopy during routine surveillance and in cases of clinical, radiographic, or physiologic suspicion of lung rejection. This prospective, nonrandomized study was conducted by the Marseille Lung Transplant Group, Marseille University Hospitals South. It included 26 lung transplant recipients (19 double-lung, four single-lung, and three heart-lung). For each patient, SPECT lung perfusion was performed before TBB as part of routine surveillance protocol and when clinically indicated. Routine surveillance included TBB at 1, 3, 6, 9, and 12 months and every 6 months thereafter. SPECT was always performed within the 24 h preceding TBB. Whenever the SPECT was abnormal, biopsies were obtained from an area corresponding to a region of hypoperfusion. Results of the study were based on 79 paired SPECT and TBB obtained from 26 patients. Concordance between SPECT and biopsy occurred in 71 instances (89.9%). Among 25 cases of normal SPECT, TBB was normal in 24 and revealed subclinical lung rejection in one. Among 54 cases of abnormal SPECT, TBB was also abnormal in 47 (87.0%), with lung rejection being the abnormality in 23 (46%). For pairs performed as part of the routine surveillance protocol (61 pairs), clinically silent lung rejection was diagnosed in 16 (26.2%). SPECT was abnormal in 15 of 16 instances and normal in only one; this patient had minimal rejection that resolved without treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

External fixation of subglottic tracheal stents.

Bronchoscopically placed silicone stents are used increasingly for treating patients with tracheal stenosis due to benign or malignant airway disease. When stenosis occurs in the immediate subglottic region, however, complications of stent insertion, especially migration, are troublesome. The purpose of this report is to describe a technique of external fixation of subglottic stents that may be used when tracheotomy, Montgomery T-tubes, or other therapeutic measures are undesirable or have failed. This technique may also be considered in carefully selected patients with severe malacia and subglottic stenosis who have failed indwelling stent placement because of stent migration.

Aged↗
PubMed1994

Development of a disposable spray canister for talc pleurodesis. A preliminary report.

Talc pleurodesis has been used for more than 50 years in both the United States and in Europe, and it has proven to be safe and effective in patients with malignant pleural effusions as well as recurrent pneumothorax. In this preliminary report, we describe a disposable, single-use spray canister that allows intrapleural administration of sterile, asbestos-free Luzenac talc, thus facilitating thoracoscopic talc insufflation for pleurodesis, particularly in patients with recurrent malignant effusions. The talc is delivered ready to use, administered via a hollow plastic delivery catheter that can be inserted through the pleural trocars used during thoracoscopy. Use of this spray canister allows practitioners to avoid complex handling and sterilization procedures required for bulk talc powder.

Aerosols↗
PubMed1993

Thoracoscopic diagnosis of pleurolithiasis after laparoscopic cholecystectomy.

We describe a patient with right pleuritic chest pain and an enlarging exudative pleural effusion four months after laparoscopic cholecystectomy. Several radiographic imaging procedures and thoracenteses were nondiagnostic. Thoracoscopy, however, revealed bilious concretions in the parietal pleura. Thoracoscopic drainage, lysis of adhesions, and antibiotic treatment of a Klebsiella pneumoniae pleuritis resulted in relief of symptoms.

Aged↗
PubMed1993

Effects of consecutive protected specimen brushing and bronchoalveolar lavage on gas exchange and hemodynamics in ventilated patients.

OBJECTIVE: To assess cardiovascular effects and the oxygenation status of mechanically ventilated patients undergoing protected specimen brushing (PSB) and bronchoalveolar lavage (BAL) under fiberoptic bronchoscopy (FOB). DESIGN: A prospective study. SETTING: Polyvalent intensive care unit in a university hospital. PATIENTS: Twelve consecutive, critically ill, intubated, and mechanically ventilated patients with hemodynamic failure requiring invasive monitoring with an indwelling radial artery catheter and indwelling Swan-Ganz catheter were included in the study. INTERVENTIONS: Hemodynamic measurements, arterial and mixed-venous blood gas analyses, and arterial blood lactate analysis were performed before and at the end of a 10-min period of mechanical ventilation with a fractional concentration of oxygen in the inspired gas (FIO2) of 1.0. The same measurements and blood samplings were repeated at the end of the PSB procedure, at the end of the BAL procedure, and 1 h after the end of the BAL. During the study period the ECG, arterial oxygen saturation (SaO2), and mixed-venous oxygen saturation (SvO2) were continuously monitored. MAIN RESULTS: A moderate increase in both mean arterial pressure and mean pulmonary arterial pressure was observed during the FOB procedure (p < 0.05). One hour after the end of BAL, the PaO2 decreased when compared with values recorded at the beginning of the procedure with the same FIO2 (p < 0.05). An increase in intrapulmonary shunt was observed at the end of BAL (p < 0.01). A moderate increase in PaCO2 was also observed after PSB (p < 0.05) and after BAL (p < 0.01). Monitoring of SaO2 permitted us to observe a significant and sustained decrease after the end of the FOB procedure from 10 to 60 min. The decrease in SvO2 was less pronounced but reached statistical significance. CONCLUSIONS: We conclude that PSB and BAL under FOB are well tolerated in critically ill, mechanically ventilated patients with hemodynamic disturbances requiring inotropic or vasopressor agents (or both); however, a modest impairment in arterial oxygenation was observed after the end of the FOB procedure.

Adult↗
PubMed1992

Endoscopic management of bronchial stenosis after double lung transplantation.

Double lung transplantation with bilateral bronchial sutures is an increasingly popular therapeutic alternative for endstage, bilateral, septic pulmonary disease; however, surgical outcome has been hampered by mechanical complications at the level of the airway anastomoses. In our institution, therefore, the protocol for surveillance includes frequent flexible fiberoptic and rigid bronchoscopy under general anesthesia in all patients. Since 1988, there were 24 double lung transplantations (mean age, 19 yr) performed at the University of Marseille Hospitals using bilateral sutures without omental wrapping. Nineteen patients had cystic fibrosis; of the ten individuals (53 percent) with cystic fibrosis who ultimately developed bronchial stenosis, six required therapeutic endoscopic intervention including dilatation or Nd:YAG laser resection. Five patients required endobronchial silicone stents. Statistically significant risk factors for postsurgical airway narrowing included young age (mean, 14.3 yr vs 24.0 yr in patients without stenosis) and prolonged mechanical ventilation prior to transplant (all five patients ventilated before surgery developed stenosis). Results of interventional bronchoscopy were good, and an excellent level of physical activity was maintained in most patients. A team familiar with all aspects of therapeutic bronchoscopy is essential to ensure proper management of airway complications in patients after lung transplantation.

Adolescent↗
PubMed1992

Safety of interventional rigid bronchoscopy using intravenous anesthesia and spontaneous assisted ventilation. A prospective study.

STUDY OBJECTIVE: To investigate the safety of total intravenous anesthesia and spontaneous assisted ventilation during interventional rigid bronchoscopy (IRB). DESIGN: Prospective, noncomparative study. SETTING: A university hospital thoracic endoscopy and laser center. PATIENTS: Eighty-three patients underwent a total of 124 procedures (including Nd:Yag laser therapy, stent insertions, transbronchial biopsies/bronchoalveolar lavages (TBB/BALs) in transplant patients and others). Results of preanesthesia consultation, endoscopic and anesthesia intervention, perioperative complications, and time spent in recovery room were recorded prospectively. RESULTS: Respiratory complications occurred in 22 procedures (18 percent) and included severe intraoperative or postoperative oxyhemoglobin desaturations (19 cases), bronchospasms/laryngospasms (two cases), and one recurrent pneumothorax. These complications were mostly related to the endobronchial surgical procedure. Respiratory complications occurred more frequently in patients with American Society of Anesthesiologists (ASA) 3 and 4 status (p < 0.005) and in patients with a karnofsky Performance Scale (KPS) below 70 (p < 0.05). No cardiac complications were noted, although 13 patients had significant underlying heart disease. Propofol was used in 121 procedures. Etomidate was used 15 times for induction and three times for both induction and maintenance in patients with ASA status 4 or low blood pressure before induction. CONCLUSION: Total intravenous anesthesia and spontaneous assisted ventilation is a well-suited technique for IRB. Severe hypoxemia, however, may occur in approximately 15 percent of patients. This complication is usually related to the procedure itself and is easy to reverse. Propofol is well tolerated in the majority of patients but it must be used with care in patients with poor functional or cardiovascular status.

Adolescent↗
PubMed1991

Hypoxemia vs sleep fragmentation as cause of excessive daytime sleepiness in obstructive sleep apnea.

To determine the effects of intermittent hypoxemia on daytime sleepiness in the clinical setting of obstructive sleep apnea syndrome, we enrolled seven patients in a prospective, randomized, crossover study. We had two experimental conditions with NCPAP treatment as follow: (1) to correct apneas, sleep fragmentation, and hypoxemia; and (2) to correct apneas and sleep fragmentation and at the same time, induce intermittent hypoxemia. The outcome variable, daytime sleepiness, was measured objectively with the multiple sleep latency test following completion of baseline and each treatment condition. Compared with sleep latencies in the untreated condition, both experimental treatment arms prolonged sleep latencies (p less than 0.05). We found no statistically significant differences between mean MSLT scores obtained after NCPAP treatment under hypoxemic and nonhypoxemic conditions. In summary, two nights of intermittent nocturnal hypoxemia during NCPAP treatment for OSAS did not diminish the objective improvement in daytime somnolence seen with NCPAP treatment in the absence of nocturnal hypoxemia. Results lend further support to the hypothesis relating excessive daytime sleepiness to sleep fragmentation.

Adult↗
PubMed1991

[Lasers and endoprosthesis in bronchopneumology].

During the past decade lasers, especially the Neodymium: Yttrium-Aluminum-Garnet (Nd: YAG), have transformed interventional bronchoscopy. Recent improvements of tracheobronchial prostheses have further increased the therapeutic possibilities of endoscopy. Tracheobronchial obstruction by intraluminal tumeur, stenosis, or extrinsic compression can now be palliated successfully. The future of therapeutic bronchoscopy is bright. New techniques of optic spectroscopy will allow improved detection of laser induced tissue fluorescence. Refinements of laser technology and development of visualisation systems such as endoscopic echography and electronic videoendoscopy will lead to improved diagnostic and therapeutic capabilities.

Anesthesia, General↗