Confirmation Of Placement Research Articles

A Novel Absorbable Radiopaque Hydrogel Spacer to Separate the Head of the Pancreas and Duodenum in Radiation Therapy for Pancreatic Cancer

We assessed the feasibility and theoretical dosimetric advantages of an injectable hydrogel to increase the space between the head of the pancreas (HOP) and duodenum in a human cadaveric model. Using 3 human cadaveric specimens, an absorbable radiopaque hydrogel was injected between the HOP and duodenum by way of open laparotomy in 1 case and endoscopic ultrasound (EUS) guidance in 2 cases. The cadavers were subsequently imaged using computed tomography and dissected for histologic confirmation of hydrogel placement. The duodenal dose reduction and planning target volume (PTV) coverage were characterized using pre- and postspacer injection stereotactic body radiation therapy (SBRT) plans for the 2 cadavers with EUS-guided placement, the delivery method that appeared the most clinically desirable. Modeling studies were performed using 60 SBRT plans consisting of 10 previously treated patients with unresectable pancreatic cancer, each with 6 different HOP-duodenum separation distances. The duodenal volume receiving 15Gy (V15), 20Gy (V20), and 33Gy (V33) was assessed for each iteration. In the 3 cadaveric studies, an average of 0.9cm, 1.1cm, and 0.9cm HOP-duodenum separation was achieved. In the 2 EUS cases, the V20 decreased from 3.86cm3 to 0.36cm3 and 3.75cm3 to 1.08cm3 (treatment constraint <3cm3), and the V15 decreased from 7.07cm3 to 2.02cm3 and 9.12cm3 to 3.91cm3 (treatment constraint <9cm3). The PTV coverage improved or was comparable between the pre- and postinjection studies. Modeling studies demonstrated that a separation of 8mm was sufficient to consistently reduce the V15, V20, and V33 to acceptable clinical constraints. Currently, dose escalation has been limited owing to radiosensitive structures adjacent to the pancreas. We demonstrated the feasibility of hydrogel separation of the HOP and duodenum. Future studies will evaluate the safety and efficacy of this technique with the potential for more effective dose escalation using SBRT or intensity-modulated radiation therapy to improve the outcomes in patients with unresectable pancreatic cancer.

Saline Flush versus Chest x ray in Confirmation of Central Venous Catheter Placement; a Diagnostic Accuracy Study.

Central venous catheterization (CVC) is a commonly performed procedure in critically ill patients of emergency department. This study was designed to compare the diagnostic accuracy of saline flush with CXR in confirmation of above-the-diaphragm CVC placement. This prospective cross sectional study was conducted on adult patients in need of CVC placement in emergency department. Placement Confirmation was performed with saline flush method and CXR, then chest computed tomography (CT) was performed as the gold standard. The screening performance characteristics of the two methods were calculated and compared using SPSS 21 and STATA 11. 103 cases with the mean age of 57.18±9.3 (35 -80) years were studied (52.4% male). The mean duration of procedure was 2.5±1.24 in saline flush and 32.11±5.52 minutes in CXR method (P<0.001(. The area under the ROC curves for saline flush and CXR in confirmation of CVC placement were 0.90 (95%CI: 0.70 - 0.100) and 0.80 (95%CI: 0.55 - 0.100), respectively (p = 0.317). The sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ratio of saline flush were 80%, 100%, 100, 98.9%, Infinity, and 0.01, respectively. These measures were 60%, 100%, 100%, 98%, Infinity, and 0.02 for CXR, respectively. It seems that saline flush method could be considered as a safe, rapid, and accurate bedside method for CVC placement confirmation in emergency department.

Unrecognized failed airway management using a supraglottic airway device

Background911 Emergency Medical Services (EMS) systems utilize supraglottic devices for either primary advanced airway management, or for airway rescue following failed attempts at direct laryngoscopy endotracheal intubation. There is, however, limited data on objective confirmation of supraglottic airway placement in the prehospital environment. Furthermore, the ability of EMS field providers to recognize a misplaced airway is unknown. MethodsRetrospective review of patients who underwent airway management using the King LTS-D supraglottic airway in a large urban EMS system, between 3/1/15-9/30/2015. Subjective success was defined as documentation of successful airway placement by the EMS provider. Objective success was confirmed by review of waveform capnography, with the presence of a 4-phase waveform greater than 5mmHg. Sensitivity and specificity of the field provider’s assessment of success were then calculated. ResultsA total of 344 supraglottic airway attempts were reviewed. No patients met obvious death criteria. 269 attempts (85.1%) met criteria for both subjective and objective success. 19 attempts (5.6%) were recognized failures by the EMS provider. 47 (13.8%) airways were misplaced but unrecognized by the EMS provider. 4 attempts (1.2%) were correctly placed but misidentified as failures, leading to the unnecessary removal and replacement of the airway. Sensitivity of the provider’s assessment was 98.5%; specificity was 28.7%. ConclusionThe use of supraglottic airway devices results in unrecognized failed placement. Appropriate utilization and review of waveform capnography may remedy a potential blind-spot in patient safety, and systemic monitoring/feedback processes may therefore be used to prevent unrecognized misplaced airways.

Endoscopic-Assisted Ommaya Reservoir Placement: Technical Note

Ommaya reservoir placement has been an option for patients requiring cerebrospinal fluid (CSF) access since the 1960s. It is preferred to repeat lumbar punctures, both in terms of patient comfort and the consistency of intrathecal drug concentration. Technological developments have advanced the placement technique, allowing for better accuracy and reduced complications. Freehand placement was first augmented with pneumoencephalograms and intraoperative computerized tomography (CT), then with optical-based navigation, and finally by utilizing electromagnetic neuronavigation. We outline a method of placement using electromagnetic neuronavigation and intraoperative endoscopic visualization, which allows for both real-time guidance and the confirmation of placement while maintaining tract patency for the entirety of the procedure. We make our incision and burr hole near Kocher’s point. The neuronavigation stylet is placed in a peel-away sheath (Cook Medical, Bloomington, Indiana, US), which allows us to advance into the ventricle under real-time neuronavigation guidance. After the ventricle is entered, the stylet may be withdrawn and an endoscope advanced down the sheath. The intraventricular anatomy and catheter placement are confirmed. The burr hole reservoir is attached to a ventricle catheter that has been trimmed based on trajectory measurement on preoperative imaging. The reservoir-catheter construct can then be placed and the sheath removed from around it. This method provides a high level of confidence in appropriate catheter placement.

Safety and Feasibility of Direct Magnetic Resonance Imaging-guided Transperineal Prostate Biopsy Using a Novel Magnetic Resonance Imaging-safe Robotic Device

To evaluate safety and feasibility in a first-in-human trial of a direct magnetic resonance imaging (MRI)-guided prostate biopsy using a novel robotic device. MrBot is an MRI-safe robotic device constructed entirely with nonconductive, nonmetallic, and nonmagnetic materials and developed by our group. A safety and feasibility clinical trial was designed to assess the safety and feasibility of a direct MRI-guided biopsy with MrBot and to determine its targeting accuracy. Men with elevated prostate-specific antigen levels, prior negative prostate biopsies, and cancer-suspicious regions (CSRs) on MRI were enrolled in the study. Biopsies targeting CSRs, in addition to sextant locations, were performed. Five men underwent biopsy with MrBot. Two men required Foley catheter insertion after the procedure, with no other complications or adverse events. Even though this was not a study designed to detect prostate cancer, biopsies confirmed the presence of a clinically significant cancer in 2 patients. On a total of 30 biopsy sites, the robot achieved an MRI-based targeting accuracy of 2.55 mm and a precision of 1.59 mm normal to the needle, with no trajectory corrections and no unsuccessful attempts to target a site. Robot-assisted MRI-guided prostate biopsy appears safe and feasible. This study confirms that a clinically significant prostate cancer (≥5-mm radius, 0.5 cm3) depicted in MRI may be accurately targeted. Direct confirmation of needle placement in the CSR may present an advantage over fusion-based technology and gives more confidence in a negative biopsy result. Additional study is warranted to evaluate the efficacy of this approach.

Use of Contrast-Enhanced Ultrasound for Confirmation of Central Venous Catheter Placement: Systematic Review and Meta-analysis.

The purpose of this meta-analysis was to determine the sensitivity, specificity, and positive and negative predictive values of contrast-enhanced ultrasound (US) for confirming the tip location and placement of central venous catheters in adult patients. A systematic review was performed using electronic databases, including MEDLINE, ClinicalTrials.gov, Cochrane, Embase, PubMed, and Scopus. Inclusion criteria were studies conducted on adult patients receiving an internal jugular or a subclavian central venous catheter in the emergency department or intensive care unit. Furthermore, the catheter tip location had to be checked with the use of the agitated saline contrast-enhanced US technique. A total of 2245 articles were screened by title and abstract. Seventeen articles were retrieved and assessed for the predefined inclusion criteria. Four articles and 1 abstract were used in the final analysis. Contrast-enhanced US showed pooled sensitivity of 72% (95% confidence interval, 44%-91%), pooled specificity of 100% (95% confidence interval, 99%-100%), a positive predictive value of 92.1%, and a negative predictive value of 98.5% compared with chest radiography for confirming the placement of central venous catheters. In the setting of central venous catheter placement, postprocedural contrast-enhanced US imaging is a safe, efficient, and highly specific confirmatory test for the catheter tip location compared with chest radiography.

Replacement of Dislodged Gastrostomy Tubes After Stoma Dilation in the Pediatric Emergency Department

IntroductionA dislodged gastrostomy tube (GT) is a common complaint that requires evaluation in the pediatric emergency department (ED) and, on occasion, will require stoma dilation to successfully replace the GT. The objective of this study was to describe the frequency that stoma dilation is required, the success rate of replacement, complications encountered, and the techniques used to confirm placement of the GT after dilation.MethodsWe conducted a retrospective medical record review of children 0–18 years who presented to the pediatric ED from February 2013 through February 2015 with a dislodged GT that required stoma dilation by pediatric emergency physicians with serially increasing Foley catheter sizes prior to successful placement of the GT.ResultsWe reviewed a total of 302 encounters in 215 patients, with 97 (32%) of the encounters requiring stoma dilation prior to replacing a GT. The median amount of dilation was 2 French between the initial Foley catheter size and the final GT size. There was a single complication of a mal-positioned balloon that was identified at the index visit. No delayed complications were encountered. We performed confirmation of placement in all patients. The two most common forms of confirmation were aspiration of gastric contents (56/97 [58%]) followed by contrast radiograph in 39 (40%).ConclusionThe practice of serial dilation of a gastrostomy stoma site to allow successful replacement of a gastrostomy tube in pediatric patients who present to the ED with a dislodged gastrostomy tube is generally successful and without increased complication. All patients received at least one form of confirmation for appropriate GT placement with the most common being aspiration of gastric contents.

P046: The development of a validated checklist for bougie-assisted cricothyroidotomy

Introduction: A cricothyroidotomy is a life-saving procedure and essential skill for EM physicians. The bougie-assisted cricothyroidotomy (BAC) is a newly describe technique that is both simple and reliable. There remains no consensus for the essential steps and ideal training strategy for the procedure. Using a modified Delphi process, we created an expert-derived checklist as a transferable educational tool for BAC instruction. Methods: A literature search was conducted to identify relevant articles describing the steps for BAC performance. These steps formed the first-iteration checklist for the modified Delphi process. Fourteen experts from general surgery, emergency medicine, otolaryngology, and anesthesia were recruited as participants for the Delphi process which consisted of three iterations. In the first two rounds, experts ranked each checklist step on a scale of 1-7, suggested additions, and provided comments. After each round the comments and rankings were integrated and steps with an average ranking of ≤3.0 were removed from the checklist for the next round. In the final round, consensus was sought by asking experts to indicate if this checklist was acceptable for teaching BAC to a novice learner. Results: A 22-item checklist was developed from a literature review. Following a modified Delphi methodology, the final BAC checklist contained 17 items. Internal consistency of the checklist was very good (α=0.855). In the third and final round, 86% of the participants agreed that the final iteration of the checklist. There was disagreement regarding “bougie hold up” as an appropriate method to confirm bougie position within the tracheal lumen. The checklist was modified, replacing “hold up” with digital palpation in the trachea as confirmation of successful bougie placement. With these modifications, consensus was achieved. Conclusion: Using a modified Delphi process, derived from existing literature and expert opinion, a 17-item BAC checklist was developed for novice instruction. This BAC checklist represents the first consensus-based set of steps for the procedure which may serve as a useful tool for trainee instruction and evaluation. Future research is required to test the validity of this checklist in training for a BAC and its applicability within competency-based medical education.

Utilization of Thoracic Ultrasound for Confirmation of Central Venous Catheter Placement and Exclusion of Pneumothorax: A Novel Technique in Real-Time Application.

To evaluate the safety and utility of ultrasonography as a tool to confirm central venous catheter (CVC) position and to exclude insertion-related pneumothorax in place of chest radiography (CXR) in a tertiary medical intensive care unit (ICU). We randomized 60 consecutive medical ICU patients to conventional or ultrasound groups for CVC placement. Both groups had CVCs inserted under ultrasound guidance. The intervention group underwent real-time transthoracic echocardiography to assist in catheter positioning and chest ultrasonography for exclusion of pneumothorax. Our primary end point was reduction in CXR use. The secondary end point was time elapsed from the end of procedure to the availability of CVC for use. χ2 test was used to compare the 2 groups for the primary end point. T test was used to compare the 2 groups for the secondary end point. Thirty patients were randomized to the conventional group and 30 were randomized to the ultrasound group. One patient was excluded in the control group since the procedure needed to be aborted. Patient characteristics were well matched for age, body mass index, and acute physiologic assessment and chronic health evaluation (APACHE III) scores. There was a 56.7% ( P < .0001) reduction in CXR use in the ultrasound arm. Mean time to use was 53.6 minutes in the control group and 25 minutes in the ultrasound arm ( P = .0015). Mean time required to complete the procedure was 27.7 minutes in the control group and 24.1 minutes in the ultrasound group ( P = .2053). No pneumothorax was detected in either arm. Ultrasound-guided CVC placement and positioning with a minor modification in technique reduced the use of bedside CXR and reduced the time to use of the CVC.

A New Simple, Tactile, Laryngeal Manoeuver, to Confirm Correct Placement of an Endotracheal Tube

Background: Confirmation of correct placement of the endotracheal tube is vitally important when performing endotracheal intubation. Most of the tests used to confirm the correct location of the tracheal tube have their own inherent drawbacks. Herewith, we introduce a new method which we hypothesize possesses high reliability when securing the airway.Methods: One hundred and seventy eight patients, ASA 1, non-pregnant and without head and neck abnormality were studied. Anesthesia technique and monitoring were the same for all the patients. The cricothyroid complex was manipulated using a digital maneuver both after esophageal and endotracheal intubation, for all the patients and any paradoxical movement of the endotracheal tube was recorded during the maneuver to confirm either endotracheal intubation or esophageal intubation. The test parameters included true positive, false positive, true negative, false negative, sensitivity, specificity and accuracy for paradoxical motion, based on the tracheal tube position. The relationship between the extent of tracheal tube movement and the position of tracheal tube was analyzed and a p value < 0.05 was considered to be statistically significant.Results: The mean age of the patients was 40.5 ± 14.6. The paradoxical motion test was 93.3% sensitive, and 77.5% specific, in the diagnosis of correct anatomical placement of the tracheal tube. One hundred and sixty six (93.2%) patients were diagnosed as true positive. Positive and negative predictive value of paradoxical motion was 80.6% and 92.0%, respectively, with an accuracy rate of 85.4%.Conclusions: Paradoxical movement of the endotracheal tube after digital cricothyroid complex movement, is an appropriate and a diagnostic test to confirm the insertion of the tube in the trachea, and is an additional important test to ensure correct placement of the endotracheal tube.

Nasogastric tube placement confirmation: where we are and where we should be heading

Background: Insertion of a tube via the nasal passage is a common procedure which has been practiced for many years. There are various ways to assess the position of the nasogastric tube (NGT). Objectives: The objective of this study was to discuss the advantages and limitations of each method of NGT placement confirmation, to identify gaps in literature, and provide suggestions for future research. Methods: A search was performed with Pubmed, CINAHL, and Embase. The following keywords were used: “nasogastric,” “tube,” “placement,” “insertion,” and “measurement.” The results were narrowed down to those with full text available, published in the English language, those published within the last 10 years, and those studies done in the adult population. The reference lists of those articles were also referred to and relevant articles were retrieved. A final 26 relevant articles were included in this review, including six that were published more than 10 years ago but still relevant in this review. Results: A method to confirm NGT placement that is accurate, affordable, does not require gastric aspirates, and is able to be used not only upon insertion but also at regular intervals is lacking. Conclusions: This article provides a summary of the different methods of NGT placement confirmation and discusses their advantages and limitations. Gaps in literature and suggestions for future research were also deliberated.

Ultrasonography for confirmation of gastric tube placement.

Gastric tubes are commonly used for the administration of drugs and tube feeding for people who are unable to swallow. Feeding via a tube misplaced in the trachea can result in severe pneumonia. Therefore, the confirmation of tube placement in the stomach after tube insertion is important. Recent studies have reported that ultrasonography provides good diagnostic accuracy estimates in the confirmation of appropriate tube placement. Hence, ultrasound could provide a promising alternative to X-rays in the confirmation of tube placement, especially in settings where X-ray facilities are unavailable or difficult to access. To assess the diagnostic accuracy of ultrasound for gastric tube placement confirmation. We searched the Cochrane Library (2016, Issue 3), MEDLINE (to March 2016), Embase (to March 2016), National Institute for Health Research (NIHR) PROSPERO Register (to May 2016), Aggressive Research Intelligence Facility Databases (to May 2016), ClinicalTrials.gov (to May 2016), ISRCTN registry (May 2016), World Health Organization International Clinical Trials Registry Platform (to May 2016) and reference lists of articles, and contacted study authors. We included studies that evaluated the diagnostic accuracy of naso- and orogastric tube placement confirmed by ultrasound visualization using X-ray visualization as the reference standard. We included cross-sectional studies, and case-control studies. We excluded case series or case reports. Studies were excluded if X-ray visualization was not the reference standard or if the tube being placed was a gastrostomy or enteric tube. Two review authors independently assessed the risk of bias and extracted data from each of the included studies. We contacted authors of the included studies to obtain missing data. We identified 10 studies (545 participants and 560 tube insertions) which met our inclusion criteria.No study was assigned low risk of bias or low concern in every QUADAS-2 domain. We judged only three (30%) studies to have low risk of bias in the participant selection domain because they performed ultrasound after they confirmed correct position by other methods.Few data (43 participants) were available for misplacement detection (specificity) due to the low incidence of misplacement. We did not perform a meta-analysis because of considerable heterogeneity of the index test such as the difference of echo window, the combination of ultrasound with other confirmation methods (e.g. saline flush visualization by ultrasound) and ultrasound during the insertion of the tube. For all settings, sensitivity estimates for individual studies ranged from 0.50 to 1.00 and specificity estimates from 0.17 to 1.00. For settings where X-ray was not readily available and participants underwent gastric tube insertion for drainage (four studies, 305 participants), sensitivity estimates of ultrasound in combination with other confirmatory tests ranged from 0.86 to 0.98 and specificity estimates of 1.00 with wide confidence intervals.For the studies using ultrasound alone (four studies, 314 participants), sensitivity estimates ranged from 0.91 to 0.98 and specificity estimates from 0.67 to 1.00. Of 10 studies that assessed the diagnostic accuracy of gastric tube placement, few studies had a low risk of bias. Based on limited evidence, ultrasound does not have sufficient accuracy as a single test to confirm gastric tube placement. However, in settings where X-ray is not readily available, ultrasound may be useful to detect misplaced gastric tubes. Larger studies are needed to determine the possibility of adverse events when ultrasound is used to confirm tube placement.

Development of a novel technique for bilateral rectus sheath nerve blocks under laparoscopic-guidance

BackgroundBilateral rectus sheath blocks have proven to be superior to local anesthetic infiltration for umbilical incisions and have been gaining popularity for the treatment of perioperative pain in children. We aim to develop a technique of surgeon performed rectus sheath blocks under laparoscopic-guidance alone. MethodsIn phase I, we observed the laparoscopic appearance of a rectus sheath block. The pain management team performed an ultrasound-guided rectus sheath nerve block as we visualized the posterior rectus sheath with the laparoscope. In phase II, after completion of the laparoscopic procedure, we performed a rectus sheath nerve block. Ultrasound was used to identify where the local anesthetic had been injected. ResultsNineteen patients were included in this study, accounting for 38 rectus sheath blocks. In phase I, we observed with the laparoscope the delivery of ten ultrasound-guided rectus sheath blocks. In phase II, 28 laparoscopic-guided rectus sheath blocks were completed with immediate ultrasound confirmation of correct placement. ConclusionsWe have demonstrated that the rectus sheath nerve block can be performed reliably under laparoscopic-guidance alone. The efficacy of the laparoscopic-guided nerve block compared to the ultrasound-guided approach will need further study in a prospective, randomized trial. Type of studyRetrospective review. Level of evidence3.

Is confirmation of ureteric stent placement in laparoscopic pyeloplasty necessary?

Placement of an antegrade double-J (JJ) ureteric stent is an important component of pyeloplasty. Correct siting of distal end of the stent in the bladder is essential for ease of removal. To date, no studies have compared methods for confirming stent position. This study aims to address that void in the literature. Eligible patients underwent laparoscopic pyeloplasty with antegrade stent placement at our institution from 2007 to 2015 inclusive. Methods to verify distal stent position of rigid cystoscopy, artificial bladder filling or no confirmation were compared. Effectiveness was determined by the proportion of malpositioned stents detected intra-operatively compared to the total found malpositioned, both intra-operatively and during follow-up. A total of 75 patients underwent laparoscopic pyeloplasty. Forty-six (61.3%) patients had distal stent position assessed intra-operatively, comprising 27 by cystoscopy and 19 by artificial bladder filling, while for 29 (38.7%) patients no verification method was used. Cystoscopy, artificial bladder filling and no confirmation detected intra-operatively 2, 1 and 0 malpositioned stents, from malpositioned stent totals of 2, 2 and 1, respectively. Malposition of JJ ureteric stent is uncommon, and omitting intra-operative position verification appears reasonable in select cases. Artificial bladder filling can help detect malpositioned JJ stents without repositioning the patient for cystoscopy. However, our results suggest both may be unreliable. If stent malposition is suspected, certainty is desired or extended operative duration is less critical, then the surgeon should proceed with cystoscopy.

Implementation of NAP4 emergency airway management recommendations in a quaternary-level pediatric hospital.

Emergency airway management, particularly outside of the operating room, is associated with a high incidence of life-threatening adverse events. Based on the recommendations of the 4th National Audit Project, we aimed to develop hospital-wide systems changes to improve the safety of emergency airway management. We describe a framework for governance in the form of a hospital airway special interest group. We describe the development and implementation of the following systems changes: 1. A local intubation algorithm modified from the Difficult Airway Society's plan A-B-C-D approach, including clear pathways for airway escalation, and emphasizing the concepts of resuscitation prior to intubation, planning for failure, and avoidance of fixation error. 2. Simplified and standardized airway equipment located in identical airway carts in all critical care areas. 3. A preintubation checklist and equipment template to standardize preparation for airway management. 4. Availability of continuous waveform endtidal capnography in all critical care areas for confirmation of correct endotracheal tube placement. 5. Multidisciplinary team training to address the technical and nontechnical aspects of nonoperating room intubation. In addition, we describe methodology for ongoing monitoring of performance through a quality assurance framework. In conclusion, changes in the process of emergency airway management at a hospital level are feasible through collaboration. Their impact on patient-based outcomes requires further study.

Service development of a nurse-led community-based PICC insertion service.

Patients receiving intravenous therapy require reliable venous access. Typically patients with poor peripheral access or requiring long-term treatment from an outpatient antibiotic therapy (OPAT) service need to receive secondary care input for safe central line placement, and radiological confirmation of the correct line tip placement where necessary, if treatment is to proceed as planned. Technological developments that enable accurate ultrasound-guided vein selection and electrocardiograph (ECG)-guided central line tip placement have eliminated the need for radiological or fluoroscopic confirmation of correct tip placement for peripherally placed central catheters (PICCs). This article outlines the development of an out-of-hospital nurse-led PICC insertion service using the Sherlock 3CG® Tip Confirmation System (C.R Bard) to meet the needs of patients requiring long-term intravenous treatment from an OPAT service, and its impact on reducing treatment delays and the need for secondary care intervention.

Endotracheal tube placement confirmation: 100% sensitivity and specificity with sustained four-phase capnographic waveforms in a cadaveric experimental model

BackgroundWaveform capnography is considered the gold standard for verification of proper endotracheal tube placement, but current guidelines caution that it is unreliable in low-perfusion states such as cardiac arrest. Recent case reports found that long-deceased cadavers can produce capnographic waveforms. The purpose of this study was to determine the predictive value of waveform capnography for endotracheal tube placement verification and detection of misplacement using a cadaveric experimental model. MethodsWe conducted a controlled experiment with two intubated cadavers. Tubes were placed within the trachea, esophagus, and hypopharynx utilizing video laryngoscopy. We recorded observations of capnographic waveforms and quantitative end-tidal carbon dioxide (ETCO2) values during tracheal versus extratracheal (i.e., esophageal and hypopharyngeal) ventilations. Results106 and 89 tracheal ventilations delivered to cadavers one and two, respectively (n=195) all produced characteristic alveolar waveforms (positive) with ETCO2 values ranging 2–113mmHg. 42 esophageal ventilations (36 to cadaver one and 6 to cadaver two), and 6 hypopharyngeal ventilations (4 to cadaver one and 2 to cadaver two) all resulted in non-alveolar waveforms (negative) with ETCO2 values of 0mmHg. Esophageal and hypopharyngeal measurements were categorized as extratracheal (n=48). A binary classification test showed no false negatives or false positives, indicating 100% sensitivity (NPV 1.0, 95%CI 0.98–1.00) and 100% specificity (PPV 1.0, 95%CI 0.93–1.00). ConclusionThough current guidelines question the reliability of waveform capnography for verifying endotracheal tube location during low-perfusion states such as cardiac arrest, our findings suggest that it is highly sensitive and specific.

A forgotten nasogastric feeding tube that refuses to get out

Key Clinical MessageNasogastric tubes (NGT) are extensively used and generally harmless, yet loop formation and malpositioning are often reported especially when using thin NGT for enteral feeding which placed blindly; therefore, diligent follow‐up of NGT is required with confirmation of right placement, changing it to PEG if long use of NGT needed.

Optimization of Ultrasound Transducer Positioning for Endotracheal Tube Placement Confirmation in Cadaveric Model

Sonography has been suggested as a possible means of endotracheal tube (ETT) placement confirmation. However, optimum ultrasound transducer placement has not been established. Using a cadaveric model, ETT placement by the sonographic appearance at the thyroid cartilage, cricoid cartilage, and suprasternal notch in the upper airway was assessed to determine which ultrasound transducer placement offered the most optimal images for ETT confirmation in the airway. One provider intubated 5 cadavers, with the ultrasound transducer at each of the 3 levels, for a total of 30 intubations per specimen, while 2 providers assigned a visual score of 1 (subtle), 2 (clear), or 3 (pronounced) to each sonogram of the ETT in the airway. At the level of the thyroid cartilage, tracheal intubation was detected at a rate of 40%, with a median visualization scale of 1 (subtle movement). At the level of the cricoid cartilage, the visualization scale improved to a median of 2 (clear movement), with a 70% intubation detection rate. At the level of the suprasternal notch, 100% of the tracheal intubations were visualized on sonography, with a median score of 3 (pronounced movement). In comparing sonographic detection of ETT placement at 3 levels of the upper airway in a cadaveric model, our results clearly indicate that visualization was superior at the level of the suprasternal notch, with 100% of intubations detected with the best visualization scores.

Screening Characteristics of Bedside Ultrasonography in Confirming Endotracheal Tube Placement; a Diagnostic Accuracy Study.

Confirmation of proper endotracheal tube placement is one of the most important and lifesaving issues of tracheal intubation. The present study was aimed to evaluate the accuracy of tracheal ultrasonography by emergency residents in this regard. This was a prospective, cross sectional study for evaluating the diagnostic accuracy of ultrasonography in endotracheal tube placement confirmation compared to a combination of 4 clinical confirmation methods of chest and epigastric auscultation, direct laryngoscopy, aspiration of the tube, and pulse oximetry (as reference test). 150 patients with the mean age of 58.52 ± 1.73 years were included (56.6% male). Sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratio of tracheal ultrasonography in endotracheal tube confirmation were 96 (95% CI: 92-99), 88 (95% CI: 62-97), 98 (95% CI: 94-99), 78 (95% CI: 53-93), 64 (95% CI: 16-255), and 0.2 (95% CI: 0.1-0.6), respectively. The present study showed that tracheal ultrasonography by trained emergency medicine residents had excellent sensitivity (>90%) and good specificity (80-90) for confirming endotracheal tube placement. Therefore, it seems that ultrasonography is a proper screening tool in determining endotracheal tube placement.