Respiratory symptoms due to a twisted nasogastric tube: A case report.

Insertion of a nasogastric tube (NGT) is generally considered safe; however, it is not without risk, and in cases of misplacement, complications and even death may occur. In this article, we reported a case of NGT misplacement in a 75-year-old male, which resulted in aspiration pneumonia. We also reviewed published cases of NGT misplacement. Clinicians should pay enough attention to the confirmation of the proper placement of an NGT. A systematic approach for NGT insertion and confirmation is required to prevent misplacement.

Iranian school-aged twin registry: preliminary reports and project progress.

BACKGROUND: National Persian school-aged twin registry was established to provide a platform for twin studies. In this report, we describe defining registry characteristics, database design, and preliminary results regarding gathered data in the first phase of the registry program. METHOD: Through focus group discussions, the required data elements to design the database and data collection process were defined. First, a list of twins in school-aged groups was retrieved from the electronic database of the Ministry of Education. Tehran schools were selected for the first phase of our registry. Standard "Pea-in-Pods" questionnaire and twins' similarity questionnaires were filled out by the parents themselves in addition to demographic information. Data were analyzed using SPSS v.22. RESULTS: The first national school-aged twin registry was established in 2018. Firstly, the required data sets and data collection process were defined using focus group discussions. At the country level, the initial information on 189,738 students was retrieved from the national database of the Ministry of Education. They were born between 2003 and 2017, of which 94,997 are boys (50.1%) and 94,741 are girls (49.9%). Of them, a total of 5,642 pairs of school-aged twins participated in the first phase of our program. Our sample size comprised 9772 twins, 906 triples, and 92 quadruplets. The analysis of the zygosity questionnaire showed that 14% of twin pairs were identified as monozygotic twins. CONCLUSION: Recruiting school-aged twins through school health assistants leads to high enrollment and decreasing costs for the twin registry. The study showed a high rate of dizygotic twins that need to be verified by twin bio-sample in the next phase of studies.

Design and evaluation of a Mobile-Based decision support system to enhance lung transplant candidate assessment and management: knowledge translation integrated with clinical workflow.

BACKGROUND: Accurate and timely decision-making in lung transplantation (LTx) programs is critical. The main objective of this study was to develop a mobile-based evidence-based clinical decision support system (CDSS) to enhance the management of lung transplant candidates. METHOD: An iterative participatory software development process was employed to develop the ImamLTx CDSS. This study was accomplished in three phases. First, required data and standard clinical workflow were identified according to the literature review and expert consensus. Second, a rule-based knowledge-based CDSS application was developed. In the third phase, this CDSS was evaluated. The evaluation was done using the standard Post-Study System Usability Questionnaire (PSSUQ 18.3) and ten usability heuristics factors for user interface design. RESULTS: According to expert consensus, fifty-five data items were identified as essential data sets using the Content Validity Ratio (CVR) formula. By integrating information flow in clinical practices with clinical protocols, more than 450 rules and 500 knowledge statements were extracted. This CDSS provides clinical decision support on an Android platform regarding inclusion and exclusion referral criteria, optimum transplant time based on the type of lung disease, findings of initial assessment, and the overall evaluation of lung transplant candidates. Evaluation results showed high usability ratings due to the fact provided accuracy and sensitivity of this lung transplant CDSS with the information quality domain receiving the highest score (6.305 from 7). CONCLUSION: Through a stepwise approach, the ImamLTx CDSS was developed to provide LTx programs with timely patient data access via a mobile platform. Our results suggest integration with existing workflow to support clinical decision-making and provide patient-specific recommendations.

The effect of vestibular rehabilitation in Meniere's disease: a systematic review and meta-analysis of clinical trials.

BACKGROUND: Meniere's disease (MD) is a complex disease that can severely affect the quality of life. In this systematic review and meta-analysis, we aimed to investigate the effect of vestibular rehabilitation (VR) versus control/other interventions on the quality of life in patients with MD. METHODS: We searched six electronic databases (PubMed/MEDLINE, Web of Science, EMBASE, Scopus, ProQuest, CENTRAL) from inception to September 30, 2022 with no language restriction for publications comparing the effect of VR with control/ other interventions in patients with MD. The primary outcome was quality of life assessed by dizziness handicap inventory (DHI). RESULTS: Overall, three studies with a total of 465 patients were included in the meta-analysis. All the included studies reported immediate-term DHI scores. A medium effect (standardized mean difference [SMD] = - 0.58, 95% confidence interval [CI] - 1.12; - 0.05) was observed favoring the use of VR to improve DHI scores in patients with MD in the immediate term. Moreover, there was severe heterogeneity in immediate DHI scores among the included studies (χ2 = 22.33, P = 0.00, I2 = 82.1%). CONCLUSIONS: VR rehabilitation can improve the quality of life in patients with MD immediately after treatment. Since all the included studies had a high risk of bias and none had long-term follow-ups, further high-quality research is required to determine the short-, intermediate-, and long-term effects of VR compared to control/other interventions.

Machine learning-based techniques to improve lung transplantation outcomes and complications: a systematic review.

BACKGROUND: Machine learning has been used to develop predictive models to support clinicians in making better and more reliable decisions. The high volume of collected data in the lung transplant process makes it possible to extract hidden patterns by applying machine learning methods. Our study aims to investigate the application of machine learning methods in lung transplantation. METHOD: A systematic search was conducted in five electronic databases from January 2000 to June 2022. Then, the title, abstracts, and full text of extracted articles were screened based on the PRISMA checklist. Then, eligible articles were selected according to inclusion criteria. The information regarding developed models was extracted from reviewed articles using a data extraction sheet. RESULTS: Searches yielded 414 citations. Of them, 136 studies were excluded after the title and abstract screening. Finally, 16 articles were determined as eligible studies that met our inclusion criteria. The objectives of eligible articles are classified into eight main categories. The applied machine learning methods include the Support vector machine (SVM) (n = 5, 31.25%) technique, logistic regression (n = 4, 25%), Random Forests (RF) (n = 4, 25%), Bayesian network (BN) (n = 3, 18.75%), linear regression (LR) (n = 3, 18.75%), Decision Tree (DT) (n = 3, 18.75%), neural networks (n = 3, 18.75%), Markov Model (n = 1, 6.25%), KNN (n = 1, 6.25%), K-means (n = 1, 6.25%), Gradient Boosting trees (XGBoost) (n = 1, 6.25%), and Convolutional Neural Network (CNN) (n = 1, 6.25%). Most studies (n = 11) employed more than one machine learning technique or combination of different techniques to make their models. The data obtained from pulmonary function tests were the most used as input variables in predictive model development. Most studies (n = 10) used only post-transplant patient information to develop their models. Also, UNOS was recognized as the most desirable data source in the reviewed articles. In most cases, clinicians succeeded to predict acute diseases incidence after lung transplantation (n = 4) or estimate survival rate (n = 4) by developing machine learning models. CONCLUSION: The outcomes of these developed prediction models could aid clinicians to make better and more reliable decisions by extracting new knowledge from the huge volume of lung transplantation data.

Applied techniques for putting pre-visit planning in clinical practice to empower patient-centered care in the pandemic era: a systematic review and framework suggestion.

BACKGROUND: One of the main elements of patient-centered care is an enhancement of patient preparedness. Thus, pre-visit planning assessment tools was emerged to prepare and involve patients in their treatment process. OBJECTIVE: The main objective of this article was to review the applied tools and techniques for consideration of putting pre-visit planning into practice. METHODS: Web of Science, Scopus, IEEE, and PubMed databases were searched using keywords from January 2001 to November 2020. The review was completed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Then, qualitative analysis was done to suggest an appropriate framework by mapping the main concepts. RESULTS: Out of 385 citations were retrieved in initial database searches, 49 studies from ten countries were included. Applied pre-visit techniques can be classified into eight categories. Our results showed that almost 81% of studies were related to procedures that were done between each visit, while 42% of articles were related to before visits. Accordingly, the main approach of included articles was patient preparedness. While 38 studies reported this approach is effective, three studies reported the effectiveness of such tools as moderate, only two articles believed it had a low effect on improving patient-centered care. CONCLUSION: This survey summarized the characteristics of published studies on pre-visit planning in the proposed framework. This approach could enhance the quality of patient care alongside enhancement patient-provider communication. However, such an approach can also be helpful to control pandemic diseases by reducing unnecessary referrals.

An information-based framework for development national twin registry: Scoping review and focus group discussion.

BACKGROUND: Registries in various clinical domains have been established in the last decades. The specific genetic structure of twins has enabled researchers to find answers to the role of genetics and the environment in medical sciences. Thus, twin registries were developed across the world to support twin studies. Our main objective was to devise a conceptual model for developing the national twin registry to ensure the success of this registry. METHODS: In this descriptive and qualitative study, the combination of literature review and focus group discussions was applied to achieve suitable models for developing a national twin registry based on lessons learned from founded registries. The qualitative synthesis and reporting results were conducted based on the COREQ checklist. RESULTS: According to a systematic literature review, the characteristics and employed strategies employed by established twin registries were recognized. Moreover, based on our objectives, suitable models for registry development were defined. The source of information, the different levels of data, and the information flow were determined based on this model. CONCLUSION: Suggesting a conceptual framework for twin registry development at the national level based on the experiences of other countries could contribute to a greater understanding of twin registry implementation efficiently.

Suggesting a framework for preparedness against the pandemic outbreak based on medical informatics solutions: a thematic analysis.

BACKGROUND: When an outbreak emerged, each country needs a coherent and preventive plan to deal with epidemics. In the era of technology, adopting informatics-based solutions is essential. The main objective of this study is to propose a conceptual framework to provide a rapid and responsive surveillance system against pandemics. METHODS: A three-step approach was employed in this research to develop a conceptual framework. These three steps comprise (1) literature review, (2) extracting and coding concepts, and determining main themes based on thematic analysis using ATLAS.ti® software, and (3) mapping concepts. Later, all of the results synthesized under expert consultation to design a conceptual framework based on the main themes and identified strategies related to medical informatics. RESULTS: In the literature review phase, 65 articles were identified as eligible studies for analysis. Through line by line coding in thematic analysis, more than 46 themes were extracted as potential foremost themes. Based on the key themes and strategies were employed by studies, the proposed framework designed in three main components. The most appropriate strategies that can be used in each section were identified based on the demands of each part and the available solutions. These solutions were employed in the final framework. CONCLUSION: The presented model in this study can be the first step for a better understanding of the potential of medical informatics solutions in promoting epidemic disease management. It can be applied as a reference model for designing intelligent surveillance systems to prepare for probable future pandemics.

A novel pathogenic variant in the LRTOMT gene causes autosomal recessive non-syndromic hearing loss in an Iranian family.

BACKGROUND: Hearing loss (HL) is the most common sensorineural disorder with high phenotypic and genotypic heterogeneity, which negatively affects life quality. Autosomal recessive non-syndromic hearing loss (ARNSHL) constitutes a major share of HL cases. In the present study, Whole exome sequencing (WES) was applied to investigate the underlying etiology of HL in an Iranian patient with ARNSHL. METHODS: A proband from an Iranian consanguineous family was examined via WES, following GJB2 sequencing. WES was utilized to find possible genetic etiology of the disease. Various Bioinformatics tools were used to assess the pathogenicity of the variants. Co-segregation analysis of the candidate variant was carried out. Interpretation of variants was performed according to the American College of Medical Genetics and Genomics (ACMG) guidelines. RESULTS: WES results showed a novel frameshift (16 bp deletion) variant (p.Ala170Alafs*20) in the LRTOMT gene. This variant, which resides in exon 6, was found to be co-segregating in the family. It fulfils the criteria set by the ACMG guidelines of being pathogenic. CONCLUSION: Here, we report successful application of WES to identify the molecular pathogenesis of ARNSHL, which is a genetically heterogeneous disorder, in a patient with ARNSHL.

Whole exome sequencing identifies novel compound heterozygous pathogenic variants in the MYO15A gene leading to autosomal recessive non-syndromic hearing loss.

Autosomal recessive non-syndromic hearing loss (ARNSHL) is a highly heterogeneous disease, for which more than 70 genes have been identified. MYO15A mutations have been reported to cause congenital severe-to-profound HL. In this study, we applied the whole exome sequencing (WES) to find the cause of HL in an Iranian family. A proband from an Iranian non-consanguineous family with hearing impaired parents, was examined via WES, after excluding GJB2 mutations as the most common ARNSHL gene via Sanger sequencing. Co-segregation analysis of the candidate variant was done in the family members. Interpretation of variants was according to the American College of Medical Genetics and Genomics (ACMG) guidelines. WES results showed novel compound heterozygous variants (p.Arg1507Ter and p.Val2815Valfs*10) in the MYO15A gene. These two variants, residing in highly conserved regions, were found to be co-segregating in the family and fulfill the criteria of being categorized as pathogenic, according to the ACMG guidelines. Here, we report successful application of WES to identify the molecular pathogenesis of ARNSHL in a patient with ARNSHL, as an example of an extremely heterogeneous disease. In agreement with previous studies, MYO15A is regarded to be important in causing HL in Iran.

A Novel Cadherin 23 Variant for Hereditary Hearing Loss Reveals Additional Support for a DFNB12 Nonsyndromic Phenotype of CDH23.

BACKGROUND AND OBJECTIVES: Identification of the pathogenic mutations underlying hereditary hearing loss (HL) is difficult, since causative mutations in 60 different genes have so far been reported. METHODS: A comprehensive clinical and pedigree examination was performed on a multiplex family suffering from HL. Direct sequencing of GJB2 and genetic linkage analysis of 5 other most common recessive nonsyndromic HL (ARNSHL) genes were accomplished. Next-generation sequencing (NGS) was utilized to reveal the possible genetic etiology of the disease. RESULTS: NGS results showed a novel rare variant c.2977G>A (p.Asp993Asn) in the CDH23 gene. The variant, which is a missense in exon 26 of the CDH23 gene, fulfills the criteria of being categorized as pathogenic according to the American College of Medical Genetics and Genomics (ACMG) guideline. Electroretinography rejects the Usher syndrome in the family. CONCLUSIONS: The present study shows that an accurate molecular diagnosis based on NGS technologies largely improves molecular-diagnostic outcome and thus genetic counseling, and helps to clarify the recurrence risk in deaf families.

A Novel Pathogenic Variant in the CABP2 Gene Causes Severe Nonsyndromic Hearing Loss in a Consanguineous Iranian Family.

BACKGROUND AND OBJECTIVES: Hereditary hearing loss (HL) can originate from mutations in one of many genes involved in the complex process of hearing. CABP2 mutations have been reported to cause moderate HL. Here, we report the whole exome sequencing (WES) of a proband presenting with prelingual, severe HL in an Iranian family. METHODS: A comprehensive family history was obtained, and clinical evaluations and pedigree analysis were performed in the family with 2 affected members. After excluding mutations in the GJB2 gene and 7 other most common autosomal recessive nonsyndromic HL (ARNSHL) genes via Sanger sequencing and genetic linkage analysis in the family, WES was utilized to find the possible etiology of the disease. RESULTS: WES results showed a novel rare variant (c.311G>A) in the CABP2gene.This missense variant in the exon 4 of the CABP2gene meets the criteria of being pathogenic according to the American College of Medical Genetics and Genomics (ACMG) interpretation guidelines. CONCLUSIONS: Up to now, 3 mutations have been reported for the CABP2gene to cause moderate ARNSHL in different populations. Our results show that CABP2variantsalso cause severe ARNSHL, adding CABP2to the growing list of genes that exhibit phenotypic heterogeneity. Expanding our understanding of the mutational spectrum of HL genes is an important step in providing the correct clinical molecular interpretation and diagnosis for patients.

Effect of transcranial direct current stimulation on short-term and long-term treatment of chronic tinnitus.

OBJECTIVE: This study was conducted to investigate the effectiveness of anodal and cathodal methods in reducing the intensity of tinnitus and to compare them with the control. METHODOLOGY: This randomized double-blind clinical trial with case and control groups was conducted in Al-Zahra Hospital in Isfahan between 2015 and 2016. In this trial, 51 patients with tinnitus, for at least one year, were selected among those outpatients visiting the throat, nose and ear clinic within this period. Inclusion criteria were patients on electrical stimulation prohibition, with Ménière's disease, otosclerosis, chronic headache, and pulsatile tinnitus. Patients were randomly divided in three equal-sized groups: anodal stimulation group, cathodal stimulation group, and control group. The subjects received 20-min current stimulation (2 mA). Five subjects were selected from those with a significant difference between the stimulated states (anodal or cathodal) and/or control. They received weekly transcranial electrical stimulation for two months, and their long-term recovery from tinnitus was investigated. Data analysis was done with SPSS20. RESULTS: Findings showed no significant between-groups difference in mean scores of tinnitus before the intervention (p = .68); whereas, this difference was significant immediately after the intervention (p = .02) and 1 h after it (p = .03). The mean score of tinnitus in the anodal stimulation group was significantly lower than the control; whereas, no significant difference was observed between the anodal and cathodal stimulation groups, and between the cathodal and control groups (p < .05). Findings also showed that the mean scores of tinnitus in two cathodal stimulation groups (p = .24) and control group (p = .62) were not significantly different at three different points of time; whereas, this score was significantly different in the anodal group at these time points (p = .01). CONCLUSION: In conclusion, anodal stimulation was more effective than the cathodal and control stimulation in reducing the intensity of tinnitus in the short term.

Reflux esophagitis in war-related sulfur mustard lung disease.

UNLABELLED: Background Sulfur mustard (SM) has acute and chronic effects on skin and mucosal surfaces. The aim of the study was to evaluate the frequency of esophagitis in a historical cohort of veterans who had been exposed to SM in Iran-Iraq war nearly 25 years ago. METHODS: One hundred two veterans with dyspepsia and/or heartburn underwent esophago-gastroduodenoscopy. Of them, 52 cases had been exposed to SM and had chronic mustard lung disease. Controls included 50 veterans without SM exposure. Esophagitis was defined according to standard criteria. RESULTS: 81.6% of cases and 70.6% of controls had heart burn and/or regurgitation (p= 0.224). Esophagitis was seen in 40% of cases and 26.5% of controls (p= 0.155). CONCLUSION: Based on our findings, SM exposure seems not to be associated with increased esophagitis.

Conceptual framework for establishing twins prevention and continuous health promotion programme: a qualitative study.

BACKGROUND: Twin registries and cohorts face numerous challenges, including significant resource allocation, twins' recruitment and retention. This study aimed to assess expert feedback on a proposed pragmatic idea for launching a continuous health promotion and prevention programme (HPPP) to establish and maintain twin cohorts. DESIGN: A qualitative study incorporating an inductive thematic analysis. SETTING: Tehran University of Medical Sciences. PARTICIPANTS: Researchers with expertise in twin studies participated in our study. ANALYSIS AND DESIGN: Expert opinions were gathered through focus group discussions (FGDs). Thematic analysis was employed to analyse the findings and develop a model for designing a comprehensive, long-term health promotion programme using ATLAS.ti software. Additionally, a standardised framework was developed to represent the conceptual model of the twin HPPP. RESULTS: Eight FGDs were conducted, involving 16 experts. Thematic analysis identified eight themes and seven subthemes that encompassed the critical aspects of a continuous monitoring programme for twin health. Based on these identified themes, a conceptual framework was developed for the implementation of an HPPP tailored for twins. CONCLUSION: This study presented the initial endeavour to establish a comprehensive and practical solution in the form of a continuous HPPP designed to tackle the obstacles of twins' cohorts.

Black pigment on EBUS-TBNA sampling: A case of malignant melanoma.

The visualization of black pigment during EBUS-TBNA suggests a relapse of melanoma. This case highlights the value of EBUS-TBNA in diagnosing metastatic melanoma, particularly when the macroscopic appearance of the aspirate suggests the diagnosis.

Post-operative arrest following pectus excavatum repair: A case report with a systematic review of the published case reports.

Key Clinical Message: Common complications after PE surgery include ventricular tachycardia, cardiac arrest, pneumothorax, and bar displacement. These can lead to severe outcomes, emphasizing the need for caution and meticulous post-operative monitoring. Patients and their families should be well-informed about potential risks during the consent process. Abstract: The objective of this study was to raise awareness among medical staff and surgeons about potential complications, particularly rare and life-threatening ones, associated with pectus excavatum (PE) surgery. PE is the most common chest wall deformity, characterized by sternal depression. Patients primarily seek treatment for cosmetic concerns, but some also report exercise intolerance and shortness of breath. Although surgical repair is the standard treatment, the incidence and nature of severe complications remain unclear and underreported. This study presents a case of a lethal cardiac event following PE surgery and conducts a systematic review of published case reports. This study describes a case of a lethal complication of ventricular fibrillation and cardiac arrest following the Ravitch procedure for correction of PE in a 10-year-old boy. A systematic review of relevant cases of PE surgery complications was conducted. Of the 506 initial records retrieved, 93 case reports from 83 articles were identified over the 23 years. Among them, 72 patients were male, and 20 cases were female. The average age of patients was 19.2 ± 7.7 years (range: 5-53). Complications had occurred up to 37 years from the time of surgery, with most of the cases (22.5%) occurring during the operation. The most frequent complications included cardiothoracic issues and displacement of the implanted steel bar. In nine patients, complications led to fatal outcomes. Due to the possible risks of PE surgery, particularly in cosmetically motivated cases, surgeons must exercise extreme caution and remain vigilant for rare and potentially life-threatening complications.

The Application of Knowledge-Based Clinical Decision Support Systems to Enhance Adherence to Evidence-Based Medicine in Chronic Disease.

Among the technology-based solutions, clinical decision support systems (CDSSs) have the ability to keep up with clinicians with the latest evidence in a smart way. Hence, the main objective of our study was to investigate the applicability and characteristics of CDSSs regarding chronic disease. The Web of Science, Scopus, OVID, and PubMed databases were searched using keywords from January 2000 to February 2023. The review was completed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Then, an analysis was done to determine the characteristics and applicability of CDSSs. The quality of the appraisal was assessed using the Mixed Methods Appraisal Tool checklist (MMAT). A systematic database search yielded 206 citations. Eventually, 38 articles from sixteen countries met the inclusion criteria and were accepted for final analysis. The main approaches of all studies can be classified into adherence to evidence-based medicine (84.2%), early and accurate diagnosis (81.6%), identifying high-risk patients (50%), preventing medical errors (47.4%), providing up-to-date information to healthcare providers (36.8%), providing patient care remotely (21.1%), and standardizing care (71.1%). The most common features among the knowledge-based CDSSs included providing guidance and advice for physicians (92.11%), generating patient-specific recommendations (84.21%), integrating into electronic medical records (60.53%), and using alerts or reminders (60.53%). Among thirteen different methods to translate the knowledge of evidence into machine-interpretable knowledge, 34.21% of studies utilized the rule-based logic technique while 26.32% of studies used rule-based decision tree modeling. For CDSS development and translating knowledge, diverse methods and techniques were applied. Therefore, the development of a standard framework for the development of knowledge-based decision support systems should be considered by informaticians.

Feasibility study and determination of prerequisites of telecare programme to enhance patient management in lung transplantation: a qualitative study from the perspective of Iranian healthcare providers.

BACKGROUND: Non-adherence to treatment plans, follow-up visits and healthcare advice is a common obstacle in the management of lung transplant patients. This study aims to investigate experts' views on the needs and main aspects of telecare programmes for lung transplantation. DESIGN: A qualitative study incorporating an inductive thematic analysis. SETTING: Lung transplant clinic and thoracic research centre. PARTICIPANTS: Clinicians: four pulmonologists, two cardiothoracic surgeons, two general physicians, two pharmacotherapists, one cardiologist, one nurse and one medical informatician. METHOD: This study adopted a focus group discussion technique to gather experts' opinions on the prerequisites and features of a telecare programme in lung transplantation. All interviews were coded and combined into main categories and themes. Thematic analysis was performed to extract the key concepts using ATLAS.Ti. Ultimately, all extracted themes were integrated to devise a conceptual model. RESULTS: Ten focus groups with 13 participants were conducted. Forty-six themes and subthemes were extracted through the thematic analysis. The main features of the final programme were extracted from expert opinions through thematic analysis, such as continuous monitoring of symptoms, drug management, providing a specific care plan for each patient, educating patients module, creating an electronic medical record to collect patient information, equipping the system with decision support tools, smart electronic prescription and the ability to send messages to the care team. The prerequisites of the system were summarised in self-care activities, clinician's tasks and required technologies. In addition, the barriers and benefits of using a telecare system to enhance the quality of care were determined. CONCLUSION: Our investigation recognised the main factors that must be considered to design a telecare programme to provide ideal continuous care for lung transplant patients. Users should further explore the proposed model to support the development of telecare interventions at the point of care.

Feasibility and safety of transglottic bronchoscopy in mechanically ventilated sheep.

PURPOSE: Although bronchoscopy can be safely performed through endotracheal tube in most intubated critically ill patients, sometimes it could lead to complications such as hypoxia and high airway pressures. Theoretically, transglottic bronchoscopy (TGB) does not interfere with mechanical ventilation and could avoid these complications. In a two-period crossover study, we compared this technique with trans-endotracheal tube bronchoscopy (TEB) in normal anesthetized sheep. METHODS: In five sheep, we did TGB first. The bronchoscope was introduced through the nasal nares and passed into the trachea via space between endotracheal tube and vocal folds. Heart rate, V(T), P(peak), and O(2) saturation were recorded. One week later, we did TEB. In another five sheep, we did TEB first and TGB later. RESULTS: P(peak) increased and V(T) and O(2) saturation decreased during TEB (53.2 ± 5.7 vs. 27.6 ± 0.6, P = 0.002; 210 ± 32 vs. 285 ± 26, P = 0.002; 94.3 ± 1.3 vs. 97.5% ± 0.5, P = 0.041, respectively), but not during TGB. The only statistically significant abnormal finding during TGB was a mild tachycardia (96.7 ± 5.7 vs. 94.7 ± 5.5, P = 0.034). CONCLUSION: Although TGB is time consuming and less convenient than TEB, it has minimal interference with mechanical ventilation. Expertise with this technique could be useful in patients with anticipated significant hypoxia and high airway pressures during bronchoscopy.