Preparation of the patient for awake flexible fiberoptic bronchoscopy

Videolaryngoscopy vs. flexible fibrescopy for tracheal intubation in patients with cervical spine immobilisation: a randomised controlled trial

In patients with cervical spine immobilisation, tracheal intubation devices other than a direct laryngoscope are frequently used to facilitate tracheal intubation and avoid related complications. In this randomised controlled trial, we compared videolaryngoscopic and fibrescopic tracheal intubation in patients with a cervical collar. Tracheal intubation was performed using either a videolaryngoscope with a non-channelled Macintosh blade (n = 166) or a flexible fibrescope (n = 164) in patients having elective cervical spine surgery whose neck was immobilised with a cervical collar to simulate a difficult airway. The primary outcome was the first attempt success rate of tracheal intubation. Secondary outcomes were the overall success rate of tracheal intubation; time to tracheal intubation; use of additional airway manoeuvres; and incidence and severity of tracheal intubation-related airway complications. First attempt success rate was higher in the videolaryngoscope group than in the fibrescope group (164/166 (98.8%) vs. 149/164 (90.9%), p = 0.003). Tracheal intubation was successful within three attempts in all patients. Median (IQR [range]) time to tracheal intubation was shorter (50.0 (41.0-72.0 [25.0-170.0]) s vs. 81.0 (65.0-107.0 [24.0-178.0]) s, p < 0.001) and additional airway manoeuvres were less frequent (30/166 (18.1%) vs. 91/164 (55.5%), p < 0.001) in the videolaryngoscope group compared with the fibrescope group. The incidence and severity of intubation-related airway complications were not different between the two groups. When performing tracheal intubation in patients with a cervical collar, videolaryngoscopy with a non-channelled Macintosh blade was superior to flexible fibrescopy.

The Difficult Airway

Airway management is a cornerstone of anesthetic practice, and difficulty with airway management has potentially grave implications-failure to secure a patent airway can result in hypoxic brain injury or death in a matter of minutes. The difficult airway in otolaryngologic surgery requires careful planning and close communication between the anesthesiologist and ENT or head and neck surgeon. Knowledge of predictive factors and a detailed preoperative evaluation can be used to predict which airway strategies are likely to be successful and which are likely to fail.

The respiratory microbiome in bronchial mucosa and secretions from severe IgE-mediated asthma patients

BACKGROUND

The bronchial microbiome in chronic lung diseases presents an abnormal pattern, but its microbial composition and regional differences in severe asthma have not been sufficiently addressed. The aim of the study was to describe the bacterial community in bronchial mucosa and secretions of patients with severe chronic asthma chronically treated with corticosteroids in addition to usual care according to Global Initiative for Asthma. Bacterial community composition was obtained by 16S rRNA gene amplification and sequencing, and functional capabilities through PICRUSt.

RESULTS

Thirteen patients with severe asthma were included and provided 11 bronchial biopsies (BB) and 12 bronchial aspirates (BA) suitable for sequence analyses. Bacteroidetes, Firmicutes, Proteobacteria and Actinobacteria showed relative abundances (RAs) over 5% in BB, a cutoff that was reached by Streptococcus and Prevotella at genus level. Legionella genus attained a median RA of 2.7 (interquartile range 1.1-4.7) in BB samples. In BA a higher RA of Fusobacteria was found, when compared with BB [8.7 (5.9-11.4) vs 4.2 (0.8-7.5), p = 0.037], while the RA of Proteobacteria was lower in BA [4.3 (3.7-6.5) vs 17.1 (11.2-33.4), p = 0.005]. RA of the Legionella genus was also significantly lower in BA [0.004 (0.001-0.02) vs. 2.7 (1.1-4.7), p = 0.005]. Beta-diversity analysis confirmed the differences between the microbial communities in BA and BB (R² = 0.20, p = 0.001, Adonis test), and functional analysis revealed also statistically significant differences between both types of sample on Metabolism, Cellular processes, Human diseases, Organismal systems and Genetic information processing pathways.

CONCLUSIONS

The microbiota in the bronchial mucosa of severe asthma has a specific pattern that is not accurately represented in bronchial secretions, which must be considered a different niche of bacteria growth.

Variability in the measurement of the methylation status of lung cancer-related genes in bronchial secretions

Assessment of the methylation status of genes related to the development of lung cancer (LC) in bronchial secretions has been proposed as a biomarker for early detection. Several techniques are available to detect gene methylation, and the method chosen may have an effect on the results. A cross-sectional study was conducted in which the methylation status of DAPK, CDKN2A (p16) and RASSF1A genes in sputum and bronchial washing (BW) from subjects at risk for LC was analyzed. The methylation results of both samples were compared, considering BW as the reference. Results obtained by methylation-sensitive PCR (MSP) were validated by methylation-sensitive high-resolution melting (MS-HRM). The methylation results obtained in sputum and BW samples did not show statistically significant differences for any of the three genes analyzed in 65 subjects (McNemar test>0.05). Concordant results between sputum and BW were found in 40 patients for DAPK (61%), in 52 patients for p16 (80%) and in 63 patients for RASSF1 (97%). More methylated samples were found in BW, however, and sputum sensitivities and specificities for the identification of methylation status were 44 and 72% for DAPK gene, 21 and 94% for p16 and 100 and 98% for RASSF1A, respectively. When MSP results were validated by MS-HRM, DAPK and p16 gene samples methylated by MSP appeared to be unmethylated by MS-HRM. One sample showing methylation of RASSF1A gene also showed methylation when tested following MS-HRM procedure. Sputum and BW samples may be considered equally valid for the identification of methylated genes in bronchial secretions. The low sensitivity of sputum for the assessment of the methylation status of DAPK and p16 genes, however, suggests that the analysis of two or more sputum samples, or of a BW obtained semi-invasively, would be needed to attain higher reliability, together with the use of confirmatory techniques for positive results.

Regulation of cough and action potentials by voltage-gated Na channels

The classical role ascribed to voltage-gated Na channels is the conduction of action potentials. Some excitable tissues such as cardiac muscle and skeletal muscle predominantly express a single voltage-gated Na channels isoform. Of the nine voltage-gated Na channels, seven are expressed in neurons, of these Nav 1.7, 1.8 and 1.9 are expressed in sensory neurons including vagal sensory neurons that innervate the airways and initiate cough. Nav 1.7 and Nav 1.9 are of particular interest as they represent two extremes in the functional diversity of voltage-gated Na channels. Voltage-gated Na channel isoforms expressed in airway sensory neurons produce multiple distinct Na currents that underlie distinct aspects of sensory neuron function. The interaction between voltage-gated Na currents underlies the characteristic ability of airway sensory nerves to encode encounters with irritant stimuli into action potential discharge and evoke the cough reflex.

Microbiome diversity in the bronchial tracts of patients with chronic obstructive pulmonary disease

Culture of bacteria from bronchial secretions in respiratory patients has low sensitivity and does not allow for complete assessment of microbial diversity across different bronchial compartments. In addition, a significant number of clinical studies are based on sputum samples, and it is not known to what extent they describe the real diversity of the mucosa. In order to identify previously unrecognized lower airway bacteria and to investigate the complexity and distribution of microbiota in patients with chronic obstructive pulmonary disease (COPD), we performed PCR amplification and pyrosequencing of the 16S rRNA gene in patients not showing signs or symptoms of infection. Four types of respiratory samples (sputum, bronchial aspirate, bronchoalveolar lavage, and bronchial mucosa) were taken from each individual, obtaining on average >1,000 16S rRNA sequences per sample. The total number of genera per patient was >100, showing a high diversity, with Streptococcus, Prevotella, Moraxella, Haemophilus, Acinetobacter, Fusobacterium, and Neisseria being the most commonly identified. Sputum samples showed significantly lower diversity than the other three sample types. Lower-bronchial-tree samples, i.e., bronchoalveolar lavage and bronchial mucosa, showed a very similar bacterial compositions in contrast to sputum and bronchial aspirate samples. Thus, sputum and bronchial aspirate samples are upper bronchial tree samples that are not representative of the lower bronchial mucosa flora, and bronchoalveolar lavage samples showed the results closest to those for the bronchial mucosa. Our data confirm that the bronchial tree is not sterile in COPD patients and support the existence a different microbiota in the upper and lower compartments.

Intra- and interobserver agreement among bronchial endosonographers for the description of intrathoracic lymph nodes

Several sonographic features observed by endobronchial ultrasonography have been suggested to be useful to predict malignancy in mediastinal lymph nodes. To evaluate agreement to describe sonographic features, 28 video images were evaluated twice by eight expert bronchoscopists. The observers reviewed each case for the presence of coagulation necrosis sign (CNS), central hilar structure (CHS), heterogeneity, distinct margin, round shape, size >1 cm and malignancy. Intraobserver agreement was almost perfect for size (κ = 0.826), substantial for CNS (κ = 0.721) and shape (κ = 0.615), and moderate for CHS (κ = 0.565), heterogeneity (κ = 0.441) and margin (κ = 0.407). Interobserver agreement was substantial for size (κ = 0.641), moderate for shape (κ = 0.445), and fair for CNS (κ = 0.340) and margin (κ = 0.274). In conclusion, inter- and intraobserver agreement of the endosonographic features for mediastinal or hilar lymph nodes is good for shape or size but not good enough for the other ultrasonographic features.

[Application of real time endobronchial ultrasound-guided transbronchial needle aspiration for lung cancer staging]

线性经支气管超声引导针吸活检（endobronchial ultrasound-guided transbronchial needle aspiration, EBUSTBNA）是新引进的技术，它是实时超声下可视淋巴结的针吸活检。尽管有研究显示，其为肺癌纵隔分期的有效方 法，但全世界多数机构并未应用该技术。本报道旨在分享我们应用EBUS-TBNA的经验，并对相关文献做一简要概 述。我们对有关该技术的已有文献进行综述，并特别介绍了我们应用该技术方面的经验。 EBUS-TBNA用以探查肺 癌患者的转移性纵隔淋巴结和/或肺门淋巴结是有效且安全的。在其它病理状态下，其亦为有效的诊断方法。

Sensitivity of linear endobronchial ultrasonography and guided transbronchial needle aspiration for the identification of nodal metastasis in lung cancer staging

The aim of this study is to determine the sensitivity of real-time endobronchial ultrasonography (EBUS)-guided transbronchial needle aspiration (TBNA) in lung cancer staging. Short- and long-axis node diameters were measured during EBUS in patients referred for lung cancer staging and sensitivities for the identification of nodal malignancy at TBNA determined. Three hundred fifteen real-time EBUS-guided TBNA nodal sampling procedures were performed in 161 patients and in 87 of them, N2/N3 metastasis was confirmed (50.9%), eliminating the need for mediastinoscopy. The median (interquartile range [IQR]) short-axis diameters of the sampled mediastinal and lobar nodes were 11 (8-15) and 8 (7-12) mm, respectively. TBNA provided satisfactory samples from 269 nodes (85.4%) and a sensitivity of 100% for the identification of malignant TBNA samples was reached for a short-axis diameter cut-off of 5 mm and a short- to long-axis ratio of 0.5. The probability of malignancy was over 90% for nodes with a short-axis diameter >20 mm and 55% for round nodes (short- to long-axis ratio of 1). In 18 out of 50 patients with a normal mediastinal computed tomography (CT) scan, the technique identified enlarged nodes in the mediastinum (36%), mainly in the subcarinal region and confirmed mediastinal malignancy in 8 (10%). Real-time EBUS-guided TBNA obtains satisfactory node samples in almost 90% of cases and improves the identification of enlarged nodes in patients with a normal mediastinum at CT. If sampling all nodes with a short-axis diameter of > or =5 mm and a short- to long-axis ratio > or =0.5, a sensitivity of 100% for the cytologic identification of malignant nodes can be expected.

[Diagnostic flexible bronchoscopy. Recommendations of the Endoscopy Working Group of the French Society of Pulmonary Medicine]

These guidelines on flexible bronchoscopy depict important clues to be known and taken into account while practicing flexible bronchoscopy, in adult, except in emergency situations. This is a practical clarification. Safety conditions, complications, anesthesia, infectious risks, cleaning and disinfection are detailed from a review of the literature. Intensive care practice of bronchoscopy requires more attention due to higher risks patients and is discussed extensively. Standards and performances of the various sampling techniques complete this work. Indications for bronchoscopy, therapeutic and paediatric bronchoscopy are not covered in these guidelines.

Utilidad de la ultrasonografía endobronquial con punción-aspiración en tiempo real para la estadificación de la neoplasia broncopulmonar

BACKGROUND AND OBJECTIVE

To determine the usefulness of endobronchial ultrasonography (EBUS) with real-time needle aspiration (NA) for lung cancer staging.

PATIENTS AND METHOD

All patients examined with EBUS and real-time NA to measure and sample mediastinal and lobar nodes for lung cancer staging during one year were included, independently of the size of the mediastinal nodes at computed tomography (CT).

RESULTS

Eighty two nodes > 5 mm were sampled using EBUS-NA (16.0 [7.2] mm; 23 cases <or= 10 mm, 28.0%), from 67 patients were examined for staging (64.0 [12.4] years). NA from 72 nodes was adequate (87.8%) (38 normal node, 46.3%; 31 neoplasia, 37.8%; 3 granuloma, 3.7%), and EBUS-NA found neoplasia in 4/23 nodes <or= 10 mm (17.4%). EBUS-NA showed neoplasic nodes in 5 out of 24 patients with a normal mediastinum at CT (20.8%). The use of EBUS-NA avoided mediastinoscopy in 62 of the 67 patients included in the study (92.5%).

CONCLUSIONS

The use of EBUS with real-time NA on mediastinal and lobar nodes obtain representative pathological samples and allow the avoidance of mediastinoscopy in over 90% of the patients referred for lung cancer staging.

Broncoscopia flexible en el niño: indicaciones y aspectos generales

There is considerable interhospital variability in the practice of flexible bronchoscopy in children. The present report aims to provide some recommendations that are supported by the Spanish Society of Pediatric Pulmonologists. We review the indications, contraindications, equipment, setting and personnel involved in flexible bronchoscopy, as well as the pre-procedure preparation of the patient, medications, post-procedure monitoring, complications, care and maintenance of instruments, and informed consent. These recommendations may be adopted, modified or rejected according to clinical needs and constraints.

Should patients undergoing a bronchoscopy be sedated?

BACKGROUND

The techniques, drugs and depth of sedation for flexible fiberoptic bronchoscopy is controversial, and several reports consider that the routine use of sedation is not a prerequisite. We evaluate whether the addition of sedation with propofol improves patient tolerance, compared to local anesthesic of the airway only.

METHODS

Eighteen patients with pneumonia undergoing flexible fiberoptic bronchoscopy were included in a randomized, single blind, prospective controlled study. The non-sedation group received airway topical anesthesia, whereas the sedation group received topical anesthesia and intravenous sedation with propofol. The degree of pain, cough, sensation of asphyxiation, degree of amnesia, global tolerance and acceptance of another bronchoscopy in the future were noted. Changes in blood pressure, heart rate and saturation of oxygen by pulse oximetry were also evaluated.

RESULTS

The patients in sedation group had less cough (P < 0.05), pain (P < 0.01) and sensation of asphyxiation (P < 0.001). Global tolerance to the procedure was significantly better in the group under sedation (P < 0.01). These patients had total amnesia to the procedure (P < 0.0001), thus is more probable that will accept another bronchoscopy in the future (P < 0.01). There was a significant rise in heart rate and blood pressure in the patients without sedation. There were no differences in oxygen saturation (P = 0.75).

CONCLUSIONS

Our results show that if we administer propofol for sedation, in addition to local anesthesia of the airway, the tolerance to the procedure is much better. Also it appears that sedation with propofol is safe if we carefully select and monitor the patient.

The role of anticholinergics in bronchoscopy. A randomized clinical trial

BACKGROUND

Anticholinergic medications have been utilized frequently prior to bronchoscopy and are thought to facilitate the drying of secretions to limit the amount of required topical anesthetic on the airway mucosa, prevent cardiac arrhythmias during the procedure, and increase patient comfort.

OBJECTIVE

To determine if atropine or glycopyrrolate, two anticholinergic agents utilized most frequently in this setting, have any significant role for this purpose.

DESIGN

Double-blind, placebo-controlled study, in which patients were randomly selected to receive atropine (0.01 mg/kg body weight, IM injection), glycopyrrolate (0.005 mg/kg, IM injection), or saline solution placebo (approximately 2 mL, IM injection) 15 to 45 min prior to being sedated with midazolam until judged to be lightly sedated.

SETTING

A large academic teaching hospital in the midwestern United States.

PARTICIPANTS

Two hundred seventeen outpatients referred for bronchoscopy who satisfied inclusion and exclusion criteria.

MEASUREMENTS AND RESULTS

Using a modified visual analog scale (0 to 100 mm), the bronchoscopist and the nurse anesthetist estimated the antisialagogic effect, effectiveness in cough suppression, and overall patient comfort during the procedure. The patients completed a similar questionnaire after recovering from the procedure. Patients were also monitored for complications (cardiac arrhythmias, oxygen desaturation, hypertension, wheezing, or coughing severe enough to curtail the procedure). There was no significant difference found among atropine, glycopyrrolate, and placebo for the primary end point of secretion control. In addition, there was no difference found between either medication and placebo for effectiveness of cough suppression, amount of topical anesthetic used, complication rates, or overall patient comfort.

CONCLUSION

The use of anticholinergic agents prior to bronchoscopy did not affect performance of bronchoscopy or complication rates, and there was no appreciable benefit from the resultant reduction in airway secretions in a population of patients receiving concurrent sedation with benzodiazepines.

Synchronous roentgenographically occult lung carcinoma in patients with resectable primary lung cancer

OBJECTIVE

To assess the prevalence of synchronous roentgenographically occult lung carcinoma (ROLC) in patients with resectable roentgenographically visible lung cancer (RVLC).

METHODS

Patients undergoing surgery for RVLC in the same University Hospital were prospectively evaluated before surgery by fluorescence bronchoscopy under local anesthesia to detect synchronous ROLC. All abnormal areas, with the exception of the RVLC, had biopsies made.

RESULTS

From June 1996 to January 1999, 43 patients (male/female ratio: 1.7/1.0) were evaluated before lobectomy (n = 34) or pneumonectomy (n = 10) for 44 primary RVLC. There were 10 T1N0, 19 T2N0, 1 T1N1, 9 T2N1, 1 T3N0, 3 T1N2, and 1 T3N1 lesions. The histologic type was mainly squamous carcinoma (n = 21) and adenocarcinoma (n = 14). All but two patients were smokers or ex-smokers (mean +/- SD, 48 +/- 28 pack-years). A total of 177 endobronchial biopsies were performed (4.1 +/- 2.5); 8 were too small to be informative, 43 showed non-preneoplastic alterations, and 50 were normal. There were 7 basal cell hyperplasias, 56 metaplasias, 9 dysplasias, and 4 carcinomas in situ (CIS). All the dysplasias and CIS lesions were observed in eight subjects. The synchronous CIS were treated by surgery (n = 1) or localized therapeutic modalities (n = 3).

CONCLUSIONS

The high prevalence of synchronous early lung cancers (9.3%) as well as metaplasia and dysplasia in this series of patients with resectable RVLC suggests that fluorescence bronchoscopy may be a useful adjunct in the preoperative evaluation of lung cancer.

Detection of bronchial preneoplastic lesions and early lung cancer with fluorescence bronchoscopy: a study about its ambulatory feasibility under local anaesthesis

BACKGROUND

Autofluorescence bronchoscopy (AB) enhances the bronchoscopist's ability to diagnose bronchial preneoplastic lesions and early cancer. We undertook a study to assess its feasibility and performance under local anaesthesia on a real ambulatory mode.

METHODS

Thirty-four consecutive patients at very high risk for lung cancer were prospectively studied by AB under local anaesthesia, without any sedation. Lidocaine doses, time, oxygen saturation, peak expiratory flow (PEF) and the number of cough episodes were measured. Continuous assessment of the respiratory sensation was obtained with a visual analog scale. A total of 172 biopsies were performed in abnormal and normal areas.

RESULTS

The procedure was long-lasting (mean +/- SD: 26.6 +/- 6.0 min), required high total doses of Lidocaine (660 +/- 107 mg) without any significant side effect, and was associated with significant decreases in O2 saturation from 98.5 +/- 1.4 to 96.1 +/- 2.5% and in PEF from 380 +/- 96 to 310 +/- 78 l/min. However, the cough counts were moderate and the majority of patients reported no respiratory discomfort. 62 hyperplasia, metaplasia, dysplasia and carcinoma in situ (CIS) were detected and the relative sensitivity of AB +/- white-light bronchoscopy (WLB) versus WLB alone was 3.75 for intraepithelial lesions corresponding to moderate dysplasia or worse.

CONCLUSIONS

AB, a procedure that increases our ability to recognize preneoplastic lesions and early lung cancer, can be performed under local anaesthesia, without systemic sedation in patients at very high risk for lung cancer.

Patient satisfaction with conscious sedation for bronchoscopy

STUDY OBJECTIVE

Bronchoscopic technique is not standardized. Controversies exist with regard to premedication with sedatives before the test. To evaluate safety and efficacy of conscious sedation, we studied 100 randomized patients undergoing diagnostic bronchoscopy; patients received premedication with lidocaine spray and atropine sulfate i.m. (nonsedation group; 50 patients) or lidocaine spray, atropine i.m. and diazepam i.v. (sedation group; 50 patients).

METHODS AND RESULTS

Monitoring during flexible fiberoptic bronchoscopy included continuous ECG and pulse oximetry. The procedure could not be completed in six patients. None received premedication with diazepam; among the patients who ended the examination, tolerance to the examination (visual analogue scale, 0 to 100; 0 = excellent; 100 = unbearable) was better in the sedation group. Low anxiety, male sex, but not age were also associated with improved patient tolerance to the test. Oxygen desaturation occurred in 17% of patients, and it was not more frequent after diazepam treatment.

CONCLUSIONS

In our study, sedation had a beneficial effect on patient tolerance and rarely induced significant alterations in cardiorespiratory monitoring parameters.

[Consensus guidelines for respiratory endoscopy issued by the Argentine Society of Bronchoesophagology]

The international consensus is that guidelines for respiratory endoscopy are inadequate, regarding such issues as institutional requirements, benefits, risks and limitations of the procedure, training programs and accreditation, with the result that the way or performing endoscopy varies according to how an operator was trained. The absence of precise recommendations means that practice is highly diverse and inappropriate use of the procedure has increased. The Argentine Consensus Group for Normalization of Respiratory Endoscopy was created in 1995 to unify criteria for several aspects of endoscopic practice. The official recommendations of the Group and of the Argentine Society of Bronchoesophagology define the indications (diagnostic, therapeutic and investigative) and contraindications (absolute, relative and high risk) for bronchoscopy. Required pre-bronchoscopic studies for routine and special cases are defined, as are indications for premedication, intubation and general anesthesia. Requirements for the setting, support personal and instruments are specified. Guidelines for topical anesthesia and techniques for insertion of the endoscope are suggested. The technique, indications and limitations of bronchoalveolar lavage, bronchial brushing and biopsy and transbronchial needle biopsy are defined. The utility and limitations of the various therapeutic techniques of bronchoscopy (laser, radiotherapy and stents) are defined. Norms to safeguard the patient, instruments and operator are emphasized.

Nebulized lidocaine administered to infants and children undergoing flexible bronchoscopy

STUDY OBJECTIVES

The purpose of this study was to evaluate the safety and efficacy of nebulized lidocaine hydrochloride as a topical anesthetic for use during flexible bronchoscopy in infants and children.

DESIGN

This was a prospective, randomized, double-blind study.

PATIENTS

Twenty consecutive patients scheduled for flexible bronchoscopy who were not intubated and had no known cardiac or hepatic disease comprised the study group.

INTERVENTIONS

The patients were randomized to receive either 8 mg/kg or 4 mg/kg of nebulized 2% lidocaine by face mask prior to bronchoscopy.

SETTING

The study took place in a bronchoscopy suite at an academic medical center.

MEASUREMENTS

To determine systemic absorption, serum lidocaine levels were obtained. To assess efficacy of nebulized lidocaine as a topical anesthetic, changes in heart rate and blood pressure were recorded, and the bronchoscopist (who did not know the lidocaine dose used) rated the ease of passage of the bronchoscope through nose, vocal cords, trachea, bronchi, and all sites overall, and the degree of cough.

RESULTS

Nebulized lidocaine was safe, was well-tolerated, and provided adequate anesthesia for half of the patients. The serum lidocaine levels were much lower than the levels in the toxic range. There was a trend toward easier passage of the bronchoscope in the high-dose group at all sites noted previously that were evaluated.

CONCLUSION

Nebulized lidocaine in doses up to 8 mg/kg appears to be safe and moderately effective as a topical anesthetic for flexible bronchoscopy in infants and children. The serum levels were remarkably low. Fifty percent of the subjects required no supplemental lidocaine.

A randomized, double-blind, placebo-controlled study of lorazepam as premedication for bronchoscopy

To our knowledge, no study has clearly demonstrated the advantage of sedative premedication for bronchoscopy. In a double-blind study, we evaluated the efficacy of oral lorazepam as premedication for bronchoscopy. One hundred patients were randomly assigned to receive placebo (group A) or lorazepam (2 mg) (group B) approximately 1.5 h before bronchoscopy. Immediately after the procedure and the following day, a questionnaire addressing the patient's perception of the procedure was administered. Specifically, subjects were asked to grade the bronchoscopy as very easy, easy, difficult, or very difficult to tolerate and if they would agree to a second bronchoscopy if believed necessary. In addition, their recollection of the procedure was graded as clear, indistinct, or not at all. No difference was found between the two groups for age, duration of the bronchoscopy, and the answers to the questionnaire administered immediately after the procedure. Most patients from both groups found their level of sedation adequate. On the following day, however, group B reported with lower frequency that the technique was difficult or very difficult (38.0% vs 65.3% for group A; p < 0.005) and that they would be less reluctant to a repeated bronchoscopy (30.0% vs 57.1% for group A; p < 0.015). Moreover, their recollection of the procedure was now less precise than for those who had received the placebo (p < 0.005). This suggests that the difference observed between the two groups at 24 h was related to the amnesic effect of lorazepam. We conclude that lorazepam, by improving patient's perception of the bronchoscopy, is a useful premedication and may facilitate patient's investigation when a second bronchoscopy becomes necessary.

Usefulness of miniature flexible fiberoptic bronchoscopy in children

A miniature flexible fiberoptic bronchoscope (FFB) (Olympus BF-N20) (2.2 mm diameter) was applied to 53 children (20 female subjects) ranging in age from 3 months to 15 years (mean, 4.19 years). Most common indications for bronchoscopy included stridor or weak cry and persistent wheezing or cough unresponsive to inhaled bronchodilators, chest physiotherapy, steroids, and antimicrobial agents. There were no complications. In 38 children (71.6 percent) it was diagnostically useful, particularly for the investigations of upper airway obstruction (66 percent). In 22 children (41.5 percent) it provided guidance for surgical interventions. The instrument was particularly useful during its application in infants with severe upper airway obstruction who otherwise would require open rigid-tube bronchoscopy in the operating room. It was of limited value when excessive bronchial secretions obstructed the view of the working field for which a bronchoscope with a built-in suction channel was needed. It is concluded that this miniature FFB is a useful diagnostic tool in infants and children particularly for obstructed upper airways but has limited applications in children with peripheral airway disease. The 2.2-mm bronchoscope may have its greatest advantage in preterm neonates and intubated infants, where the small glottic or endotracheal tube size renders the 3.5-mm bronchoscope useless.

Effects of thromboxane A2 agonist STA2 on rapidly adapting pulmonary stretch receptors in vagotomized rabbits

We investigated the responses of rapidly adapting pulmonary stretch receptors (RARs) and tracheal pressure (PT) to right atrial injections of the thromboxane A2 (TXA2) stable analogue STA2 (0.3, 1.0, and 3.0 microgram/kg) before and after administration of atropine sulfate (1 mg/kg), isoprenaline (200 micrograms/kg), indomethacin (1 mg/kg), or S-145 (0.5 mg/kg) in artificially ventilated, bilaterally vagotomized rabbits. The RARs increased their activity after STA2 administration, and the increase was dose-dependent. However, intraatrial injections of STA2 at all the doses examined had no significant effect on PT. The excitatory responses of RAR activity to STA2 (0.3-3.0 micrograms/kg) were not significantly altered by administration of atropine sulfate (anticholinergic agent), isoprenaline (bronchodilator), or indomethacin (cyclooxygenase inhibitor). However, S-145 treatment (TXA2 antagonist) blocked the STA2-induced RAR stimulation. To determine whether or not administration of STA2 causes release of acetylcholine (ACh), we also examined the effects of vagal efferent stimulation (10-15 V, 10 Hz, 1 ms), STA2 administration (3.0 micrograms/kg), and their combination on PT in rabbits associated with both artificial ventilation and bilateral vagotomy. The vagally mediated bronchoconstriction that led to an increase in PT was not enhanced by simultaneous administration of STA2 at 3.0 micrograms/kg in all of the tested animals. These results suggest that the stimulation of RARs by STA2 is not mediated by the release of ACh from the nerve endings but is probably due to a local inflammatory bronchoconstriction that does not significantly alter the value of PT.