Endotracheal Research Articles

A Novel Photoplethysmography Sensor for Vital Signs Monitoring from the Human Trachea.

Current pulse oximeter sensors can be challenged in working accurately and continuously in situations of reduced periphery perfusion, especially among anaesthetised patients. A novel tracheal photoplethysmography (PPG) sensor has been developed in an effort to address the limitations of current pulse oximeters. The sensor has been designed to estimate oxygen saturation (SpO2) and pulse rate, and has been manufactured on a flexible printed circuit board (PCB) that can adhere to a standard endotracheal (ET) tube. A pilot clinical trial was carried out as a feasibility study on 10 anaesthetised patients. Good quality PPGs from the trachea were acquired at red and infrared wavelengths in all patients. The mean SpO2 reading for the ET tube was 97.1% (SD 1.0%) vs. the clinical monitor at 98.7% (SD 0.7%). The mean pulse rate for the ET sensor was 65.4 bpm (SD 10.0 bpm) vs. the clinical monitor at 64.7 bpm (SD 9.9 bpm). This study supports the hypothesis that the human trachea could be a suitable monitoring site of SpO2 and other physiological parameters, at times where the periphery circulation might be compromised.

The Sensing Endotracheal Tube.

Current pulse oximetry sensors are not very well suited to use in anaesthetised patients as it has been shown that during episodes of reduced peripheral circulation they do not function correctly or fail all together [1], [2]. To address this problem a new design for a photoplethysmography (PPG) endotracheal (ET) sensor to monitor pulse rate and oxygen saturation (SpO2) internally is presented. Flexible printed circuit board (PCB) technology and miniature optoelectronic components have been implemented and integrated with a custom instrumentation system [3]. The sensor adheres and conforms to the curvature of standard french-gauge 7 and 8 ET tubes at the point just above the inflatable cuff within the laryngeal positioning markings. A 3D-modelled, optically clear, soft silicon encapsulation electronically and thermally isolates the electronic components whilst providing a smooth surface to aid the insertion on the ET tube during standard intubation procedures. A pilot study with 5 patients (3 Female, 2 Male), undergoing abdominal and limb laproscopic procedures has demonstrated the operation of the sensing ET tube, showing good quality red and infra-red PPG signals. Preliminary signal analysis reveals heart rate can be measured via PPG successfully, with saturation (SpO2) readings in close agreement with the commercial monitors of 97.9 % (STD 0.2 %) and 98.6 % (STD 0.8 %) respectively.

Glottic Stenosis: An Anatomic Analysis and New Treatment With a Self-Retaining Interarytenoid Spring.

Endotracheal (ET) intubation is a common cause of acquired glottic stenosis. Severe cases often require an irreversible arytenoidectomy/cordectomy, which typically results in poor voice quality. Adult human cadaver larynges were studied to gain insights about ET tube-induced posterior glottic injuries, hoping to create a less invasive remedy. Human cadaver investigation and case reports. Microlaryngeal assessments were done on 10 human cadaver larynges (5 men, 5 women) with and without ET tubes. After supracricoid soft tissue resection, measurements were obtained, including the distance between the outer diameter of the ET tube and the medial aspect of the cricoarytenoid joint facet. Additionally, measurements of the circumferential arc of differently sized ET tubes were made alongside both cricoarytenoid joint capsules. This information was used to design a silastic stent that would function as a self-retaining interarytenoid spring to treat posterior glottic stenosis in 5 patients. Four of 5 patients included in the clinical study were tracheotomy dependent, primarily because of glottic stenosis. The human surgical technique is described in detail. The shortest distance between the outer diameter of the ET tube to the medial cricoid facet averaged 5.02 mm in men and 3.62 mm in women. On the basis of the diameter of the intralaryngeal component of the initially round stent, and the position of the cricoarytenoid joint facets, the interarytenoid spring would have a subtended arc between 110° and 175°. These data helped fashion parameters for modifying a conventional T-tube to form a new self-retaining silastic interarytenoid spring. The first 5 human cases have been successful, allowing effective tracheotomy tube decannulation and excellent voice quality. The anatomic investigation herein provided key insights into ET tube-induced glottic stenosis and facilitated a new straightforward procedure to surgically improve the airway yet preserve excellent vocal function in patients with acquired glottic stenosis. Level of Evidence: NA.

Bioavailability of endotracheal epinephrine in an ovine model of neonatal resuscitation.

Distressed infants in the delivery room and those that have completed postnatal transition are both resuscitated according to established neonatal resuscitation guidelines, often with endotracheal (ET) epinephrine at the same dose. We hypothesized that ET epinephrine would have higher bioavailability in a post-transitional compared to transitioning newborn model due to absence of fetal lung liquid and intra-cardiac shunts. 15 term fetal (transitioning newborn) and 6 postnatal lambs were asphyxiated by umbilical cord and ET tube occlusion respectively. Lambs were resuscitated after 5 min of asystole. ET epinephrine (0.1 mg/kg) was administered after 1 min of positive pressure ventilation (PPV) and chest compressions, and repeated 3 min later, followed by intravenous (IV) epinephrine (0.03 mg/kg) every 3 min until return of spontaneous circulation (ROSC). Serial plasma epinephrine concentrations were measured. Peak plasma epinephrine concentrations were lower in transitioning newborns as compared to postnatal lambs: after a single ET dose (145.36 ± 135.5 ng/ml vs 553.54 ± 215 ng/ml, p < 0.01) and after two ET doses (443 ± 192.49 ng/ml vs 1406 ± 420.8 ng/ml, p < 0.01). The rates of ROSC with a single ET dose were similar in both groups (40% vs 50% in newborn and postnatal respectively, p > 0.99). There was a higher incidence of post-ROSC tachycardia and increased carotid blood flow in the postnatal group. In the postnatal period, ET epinephrine at currently recommended doses resulted in higher peak epinephrine concentrations, post-ROSC tachycardia and cerebral reperfusion without significant differences in incidence of ROSC. Further studies evaluating the optimal dose of ET epinephrine during the postnatal period are warranted.

Confirmation of endotracheal tube placement using disposable fiberoptic bronchoscopy in the emergent setting.

Patients intubated in the prehospital setting require quick and definitive confirmation of endotracheal (ET) tube placement upon arrival to the emergency department (ED). Direct and adjunct strategies exist, but each has limitations and there is no definitive gold standard. The utility of bronchoscopy in ED intubation has been studied, but scant literature exists on its use for ET tube confirmation. This study aims to assess effectiveness, ease and speed with which ET tube placement can be confirmed with disposable fiberoptic bronchoscopy. Emergency medicine residents recruited from a 3-year urban residency program received 5 minutes of active learning on a simulation mannequin using a disposable, flexible Ambu aScope interfaced with a monitor. With residents blinded, the researcher randomly placed the ET tube in the trachea, esophagus or right mainstem. Residents identified ET tube position by threading the bronchoscope through the tube and viewing distal anatomy. Each resident underwent 4 trials. Accuracy, speed and perceptions of difficulty were measured. Residents accurately identified the location of the ET tube in 88 out of 92 trials (95.7%). The median time-to-guess was 7.0 seconds, IQR (5.0-10.0). Average perceived difficulty was 1.6 on a scale from 1-5 (1 being very easy and 5 being very difficult). No tubes were damaged or dislodged. While simulation cannot completely replicate the live experience, fiberoptic bronchoscopy appears to be a quick and accurate method for ET tube confirmation. Further studies directly comparing this novel approach to established practices on actual patients are warranted.

Ideal Length of Oral Endotracheal Tube for Critically Ill Intubated Patients in an Asian Population: Comparison to Current Western Standards.

BackgroundEndotracheal (ET) intubation is used to maintain the airway patency of patients during mechanical ventilation and is inserted at a particular depth into the trachea through the nose, mouth, or through an incision in the neck. The aim of our study was to validate the ideal length of an oral endotracheal tube (ETT) in the Asian population compared to Western standards.MethodsPatient records with an oral ETT inserted between April 2011 and June 2015 in the Intensive Care Unit (ICU) of a hospital were retrospectively analyzed. The key variables included demographics, height, and ideal body weight of the patient, length of the oral ETT, and chest X-rays. Statistical analyses were performed using R software (https://cran.r-project.org/).ResultsThere were 876 incidences of oral cuffed ETT insertions in 708 adult patients ≥ 18 years of age. The median ETT depth in all the ethnic groups (Chinese, Malay, Indians, and others) was 22 cm. The median depth of oral ETTs was 22 cm in males and 21 cm in females as compared to Western standards (males: P < 0.0001; females: P = 0.93). In ICU patients intubated with an ETT at an acceptable distance from the carina (2 - 5 cm), the median ETT depth was different in males (P < 0.0001) but was similar in females (P = 0.87).ConclusionWe suggest that males and females in the Asian population, especially in South East Asia, should have their ETTs secured at the corner of mouth by at least 1 cm less in comparison to the Western population (22 cm in males and 20 cm in females).

Reducing Unplanned Extubations Across a Children's Hospital Using Quality Improvement Methods.

Children who require an endotracheal (ET) tube for care during critical illness are at risk of unplanned extubations (UE), or the unintended dislodgement or removal of an ET tube that can lead to significant patient harm. A proposed national benchmark is 1 UE per 100 ventilator days. We aimed to reduce the rate of UEs in our intensive care units (ICUs) from 1.20 per 100 ventilator days to below the national benchmark within 2 years. We identified several key drivers including ET securement standardization, safety culture, and strategies for high-risk situations. We employed quality improvement methodologies including apparent cause analysis and plan-do-study-act cycles to improve our processes and outcomes. Over 2 years, we reduced the rate of UEs hospital-wide by 75% from 1.2 to 0.3 per 100 ventilator days. We eliminated UEs in the pediatric ICU during the study period, while the UE rate in the neonatal ICU also decreased from 1.2 to 0.3 per 100 ventilator days. We demonstrated that by using quality improvement methodology, we successfully reduced our rate of UE by 75% to a level well below the proposed national benchmark.

Yield of meconium in non-vigorous neonates undergoing endotracheal suctioning and profile of all neonates born through meconium-stained amniotic fluid: a prospective observational study

ABSTRACTBackground: Delivery room management of infants born via meconium-stained amniotic fluid (MSAF) is quite controversial. No study has tried to quantify the amount of meconium that can be aspirated from the trachea of a non-vigorous neonate born through MSAF.Aims: To study the yield of meconium in non-vigorous neonates born through MSAF undergoing endotracheal (ET) suctioning.Methods: This was a prospective observational study conducted from 1 March 2015 to 31 October 2015. A total of 760 neonates born through MSAF were enrolled. All non-vigorous neonates underwent ET suctioning. Meconium aspirated was quantified as nil (no meconium aspirated), insignificant (when only streaks of meconium were present in the ET tube), minimal (when the whole length of ET tube was filled with meconium) and significant (when the whole ET tube was filled with meconium and it poured into the suction tubing or when repeat suctioning was required).Results: The amount of meconium aspirated from the trachea was nil to insignificant in 46% of the neonates who underwent tracheal suctioning. Only 14.4% of the neonates had significant meconium aspirated from the trachea. Almost 46% of the non-vigorous infants underwent tracheal suctioning without any important amount of meconium being aspirated from the trachea.Conclusion: The study further supports the recommendation put forth by the International Liaison Committee on Resuscitation (ILCOR) 2015 that selective intubation and tracheal suctioning of non-vigorous MSAF neonates might be of limited benefit.Abbreviations: ET: endotracheal; ILCOR: International Liaison Committee on Resuscitation; HIE: hypoxic ischaemic encephalopathy; LMIC: low- and middle-income countries; MAS: meconium aspiration syndrome; MSAF: meconium-stained amniotic fluid; NRP: neonatal resuscitation programme; PPHN: persistent pulmonary hypertension of the newborn; RCT: randomised controlled trial.

A Comparative Study to Assess the Effectiveness of Endotracheal Suctioning with and without Normal Saline Instillation in Terms of Physiological Parameters and Patient Outcome Measures among Mechanically Ventilated Patients in Selected Hospital of New Delhi

Intubated patients are unable to cough sufficiently to remove pulmonary secretion. Nurses occasionally encounter thick and tenacious secretions during endotracheal (ET) suctioning. To manage these secretions, normal saline instillation (NSI) is used throughout the world. The use of NSI before endotracheal suctioning is intended to lubricate the catheter, liquefy and soften secretions, and stimulate coughing. The objectives of the study were to assess the effectiveness of endotracheal suctioning with normal saline instillation in terms of physiological parameters and patient outcome among mechanically ventilated patients; to assess the effectiveness of endotracheal suctioning without normal saline instillation in terms of physiological parameters and patient outcome among mechanically ventilated patients; and to compare the effectiveness in terms of physiological parameters and patient outcome in mechanically ventilated patients with and without normal saline instillation. Methods: A quantitative research approach with comparative descriptive design was used for the study. The study was conducted in Max Super specialty Hospital, Saket and New Delhi. Purposive sampling was used for selecting 60 mechanically ventilated patients, from which 30 had undergone ET suctioning with normal saline instillation and 30 had undergone ET suctioning without normal saline instillation. Physiological parameters were assessed by using an observation checklist. Patient outcomes were assessed through observations made at 0–72 hours. Results: The significant findings of the study revealed that mechanically ventilated patients, who had undergone ET suctioning with NSI in comparison to patients who had undergone ET suctioning without NSI, were significant in terms of ventilator tidal volume at 18 hours, p value was 0.005 (p1), similarly systolic blood pressure at 6 hours and 12 hours were 0.001 and 0.049 respectively, significant at 0.05 level of significance. p value of temperature at 12 hours was 0.031, p values of ABG PaO2 at 0 hour, 6 hours,12 hours and 18 hours were 0.036, 0.005, 0.022 and 0.043 respectively, significant at 0.05 level of significance, p values of ABG Na+ at 6 hours and 12 hours were 0.003 and 0.001 respectively, significant at 0.05 level of significance, p values of ABG K+ at 6 hours were 0.046, p values of ABG Ca++ at 0 hour and 12 hours were 0.044 and 0.045 which were significant at 0.05 level respectively; however, the p2 value calculated by ANOVA test from 0–72 hours of patient outcome was not significant at 0.05 level of significance. Conclusion: The findings of the present study conclude that normal saline instillation while ET suctioning was effective in comparison to ET suctioning without normal saline instillation among mechanically ventilated patients in terms of respiratory parameters.

Estimation of length of endotracheal tube insertion by foot length in newborns

Background: Intubation is a common procedure for neonates. This study was designed to determine whether the foot length (FL) can predict the depth of endotracheal (ET) tube insertion in newborns.Methods: This one year prospective cross-sectional study was done on 50 neonates admitted to NICU under the Department of Paediatrics, Rajarajeswari Medical College and Hospital, Bangalore from January 2016 to June 2017. The FL was measured and compared with the optimal depth of ET tube insertion. The data was analysed using SPSS version 20.0.Results: The mean FL was 7.42±0.75cms and mean optimal ET tube length was 7.70±0.71cm. The correlation between optimal ET tube length and foot length was noted in 70% of the babies and significant strong positive correlation was noted between optimal ET tube length and FL (r=0.780; p&lt;0.001; R2=0.607). Significant differences were noted in mean FL and mean optimal depth of ET tube in term newborns (p=0.013) and those with normal weight (p=0.016).Conclusions: Foot length could be used as a simple and easy predictor in the estimation of endotracheal tube length in newborns.

Airway challenges in laryngotracheoplasty with Montgomery T-tube for subglottic stenosis

Airway challenges in laryngotracheoplasty with Montgomery T-tube for subglottic stenosis

Effect of intravenous midazolam on intracranial pressure during endotracheal suctioning in patients with severe head injury

Abstract Background: Patients with severe traumatic brain injury (TBI) require elective ventilation and sedation to decrease intracranial pressure (ICP) and any increase in ICP may be detrimental for the outcome in these patients. Methods: This prospective study was done in a neurotrauma intensive care unit ( ICU )of a level 1 trauma centre in India over a one month period. All adult male patients with severe TBI on mechanical ventilation and monitored for ICP were included in this study. Baseline ICP was measured before starting endotracheal (ET) suctioning and serial readings were taken during and after ET suctioning. Patients were divided into two groups (control and intervention) with intervention group receiving intravenous bolus dose of 2 mg of midazolam before ET suction. Results: A total of 20 patients were enrolled during the study period. Both groups were well matched with regards to age and admission Glasgow coma scale (GCS). There were 10 patients in the midazolam group and 10 patients in the control group. The mean rise of ICP following ET suctioning in control group was found to be 24.1mm Hg ±11.1 as compared to 18.25 mm Hg ±-9.29 in the midazolam group ( P&lt; 0.05). Conclusions: Significant rise in ICP from baseline occurs following ET suctioning in ventilated, severe TBI patients. Our study suggests that additional intravenous bolus of midazolam prior to suctioning may significantly reduce the rise in ICP and should be practiced by ICU nurses.

Iatrogenic Tracheoesophageal Fistula After Cardiopulmonary Resuscitation (CPR)

Iatrogenic tracheoesophageal (TE) fistula is a rare diagnosis that has high morbidity and mortality and requires a high index of suspicion. We report the first case of TE fistula formed during cardiac resuscitation and traumatic endotracheal (ET) intubation. A 77-year-old man with hypertension and atrial fibrillation presented after aspirating steak resulting in cardiac arrest. He went into asystole after unsuccessful abdominal thrusts. After 20 minutes of CPR by EMS and ET tube placement, return of spontaneous circulation was achieved. In the ED, he was comatose, hypotensive, and hypoxic. Chest X-ray showed rib fractures with the ET tube in the right main stem bronchus. Despite repositioning the ET tube, he remained hypoxic. Bronchoscopy showed erythema, but no foreign body. CT scan suggested food in the esophagus. Endoscopy revealed food contents in the upper third of the esophagus. After removal of the food with forceps, the scope was advanced without resistance. At 25 cm from the incisors, the ET tube balloon was seen within the esophageal lumen, suggestive of a TE fistula. Given the patient's clinical status and poor prognosis, endoscopic placement of an esophageal stent and surgical repair were deferred. On day 6 of hospitalization, he was declared brain dead and expired. Iatrogenic TE fistula can occur as a complication of prolonged ET intubation or trauma, usually taking 21-30 and 5-15 days, respectively, to develop. This is the first report of a TE fistula as an immediate complication of CPR and ET tube insertion, occurring mainly due to two factors: manipulation of the airway in the presence of food and compression of mediastinal contents between the sternum and vertebrae. Other risk factors are high ET tube cuff pressure, high airway pressures, and excessive motion of the ET tube. Tachypnea, hypoxia, and gastric distention suggest a TE fistula. Outcomes may be good when TE fistulas are detected early with prompt treatment. However, TE fistula in our patient was not detected on CT and bronchoscopy, the standard diagnostic procedures for its diagnosis. Esophageal stent placement and endoscopic suturing are potential alternatives to invasive surgical options and have good outcomes by preventing hypoxia and aspiration. This case demonstrates that a TE fistula can be an immediate complication of CPR associated with ET intubation, and although rare, it is associated with a high morbidity and mortality.Figure: Image 1 and 2: Upper endoscopy showing food at the epiglottisFigure: Image 3 and 4: ETT and balloon at the mid-esophagus

Incidence and severity of postoperative sore throat: a randomized comparison of Glidescope with Macintosh laryngoscope

BackgroundPostoperative sore throat (POST) is a common problem following endotracheal (ET) intubation during general anesthesia. The objective was to compare the incidence and severity of POST during routine intubation with Glidescope (GL) and Macintosh laryngoscope (MCL).MethodsOne hundred forty adult patients ASA I and II with normal airway, scheduled to undergo elective surgery under GA requiring ET intubation were enrolled in this prospective randomized study and were randomly divided in two groups, GL and MCL. Incidence and severity of POST was evaluated at 0, 6, 12 and 24 h after surgery.ResultsAt 0 h, the incidence of POST was more in MCL than GL (n = 41 v.s n = 22, P = 0.001), and also at 6 h after surgery (n = 37 v.s n = 23, P = 0.017). Severity of POST was more at 0, 6 and 12 h after surgery in MCL (P < 0.001, P = 0.001, P = 0.004 respectively).ConclusionsRoutine use of GL for ET tube placement results in reduction in the incidence and severity of POST compared to MCL.Trial regisrationClinicalTrials.gov NCT02848365. Retrospectively Registered (Date of registration: July, 2016).

Instillation of Endotracheal Tube Cuff with Lignocaine to reduce Post-extubation Morbidity A Randomized Control Study

Objectives: The use of endotracheal (ET) intubation is associated with post extubation emergence phenomenon comprising of sore throat, hoarseness and cough. This has been attributed to the physical effects of the tube cuff on tracheal mucosa, and thus any means to reduce this pressure effect can significantly improve on adverse symptoms. This study thus aims to compare the effects of instillation of air versus lignocaine into the ET tube cuff, on the post extubation morbidity. Methods: Fifty patients were randomized into two groups of 25 members each group A (air) and group L (lignocaine). In the former, air was filled in ET cuff, while in latter, lidocaine (4%) 5ml was instilled keeping the cuff pressure between 20-22 mmHg. Cough and hemodynamic parameters were noted at and after extubation. Extubation related morbidities were compared between the two groups. Results: With both groups showing similar demographics, there was statistically significant difference in incidence of post-operative sore throat (60% and 22.7%, p=0.003) and hoarseness (44% and 16%, p=0.029) in group A and group L respectively. The cuff volumes of agents were found to be lesser (p<0.05) with lignocaine, indicating net diffusion across cuff membrane. Post operative nausea and vomiting were also appreciably reduced after lignocaine instillation (p=0.69, 0.43). Conclusion: Instillation of Lignocaine in ET tube cuff is better in reducing post extubation sore throat, hoarseness and cough in comparison to air. It has a simple, easily reproducible and inexpensive means to alleviate emergence phenomenon.

Deep Convolutional Neural Networks for Endotracheal Tube Position and X-ray Image Classification: Challenges and Opportunities

The goal of this study is to evaluate the efficacy of deep convolutional neural networks (DCNNs) in differentiating subtle, intermediate, and more obvious image differences in radiography. Three different datasets were created, which included presence/absence of the endotracheal (ET) tube (n = 300), low/normal position of the ET tube (n = 300), and chest/abdominal radiographs (n = 120). The datasets were split into training, validation, and test. Both untrained and pre-trained deep neural networks were employed, including AlexNet and GoogLeNet classifiers, using the Caffe framework. Data augmentation was performed for the presence/absence and low/normal ET tube datasets. Receiver operating characteristic (ROC), area under the curves (AUC), and 95% confidence intervals were calculated. Statistical differences of the AUCs were determined using a non-parametric approach. The pre-trained AlexNet and GoogLeNet classifiers had perfect accuracy (AUC 1.00) in differentiating chest vs. abdominal radiographs, using only 45 training cases. For more difficult datasets, including the presence/absence and low/normal position endotracheal tubes, more training cases, pre-trained networks, and data-augmentation approaches were helpful to increase accuracy. The best-performing network for classifying presence vs. absence of an ET tube was still very accurate with an AUC of 0.99. However, for the most difficult dataset, such as low vs. normal position of the endotracheal tube, DCNNs did not perform as well, but achieved a reasonable AUC of 0.81.

Monitoring of the posterior cricoarytenoid muscle represents another option for neural monitoring during thyroid surgery: Normative vagal and recurrent laryngeal nerve posterior cricoarytenoid muscle electromyographic data.

Intraoperative neural monitoring (IONM) of laryngeal nerves using electromyography (EMG) is routinely performed using endotracheal tube surface electrodes adjacent to the vocalis muscles. Other laryngeal muscles such as the posterior cricoarytenoid muscle (PCA) are indirectly monitored. The PCA may be directly and reliably monitored through an electrode placed in the postcricoid region. Herein, we describe the method and normative data for IONM using PCA EMG. Retrospective review. Data were reviewed retrospectively for thyroid and parathyroid surgery patients with IONM of laryngeal nerves from January to August 2016. Recordings of vocalis and PCA EMG amplitudes and latencies with stimulation of laryngeal nerves were obtained using endotracheal (ET) tube-based and postcricoid surface electrodes. Data comprised EMG responses in vocalis and PCA recording channels with stimulation of the vagus, recurrent laryngeal nerve (RLN), and external branch of the superior laryngeal nerve from 20 subjects (11 left, 9 right), as well as PCA EMG threshold data with RLN stimulation from 17 subjects. Mean EMG amplitude was 725.69 ± 108.58 microvolts (µV) for the ipsilateral vocalis and 329.44 ± 34.12 µV for the PCA with vagal stimulation, and 1,059.75 ± 140.40 µV for the ipsilateral vocalis and 563.88 ± 116.08 µV for the PCA with RLN stimulation. There were no statistically significant differences in mean latency. For threshold cutoffs of the PCA with RLN stimulation, mean minimum and maximum threshold intensities were 0.37 milliamperes (mA) and 0.84 mA, respectively. This study shows robust and reliable PCA EMG waveforms with direct nerve stimulation. Further studies will evaluate feasibility and application of the PCA electrode as a complementary quantitative tool in IONM. 4. Laryngoscope, 128:283-289, 2018.

Tracking of Mesenchymal Stem Cells with Fluorescence Endomicroscopy Imaging in Radiotherapy-Induced Lung Injury

Mesenchymal stem cells (MSCs) have potential for reducing inflammation and promoting organ repair. However, limitations in available techniques to track them and assess this potential for lung repair have hindered their applicability. In this work, we proposed, implemented and evaluated the use of fluorescence endomicroscopy as a novel imaging tool to track MSCs in vivo. MSCs were fluorescently labeled and injected into a rat model of radiation-induced lung injury via endotracheal (ET) or intravascular (IV) administration. Our results show that MSCs were visible in the lungs with fluorescence endomicroscopy. Moreover, we developed an automatic cell counting algorithm to quantify the number of detected cells in each condition. We observed a significantly higher number of detected cells in ET injection compared to IV and a slight increase in the mean number of detected cells in irradiated lungs compared to control, although the latter did not reach statistical significance. Fluorescence endomicroscopy imaging is a powerful new minimally invasive and translatable tool that can be used to track and quantify MSCs in the lungs and help assess their potential in organ repair.

Emergence of Carbapenem Resistant Non-Fermenting Gram-Negative Bacilli Isolated in an ICU of a Tertiary Care Hospital.

The emergence and spread of Multi-Drug Resistant (MDR) Non-Fermenting Gram-Negative Bacilli (NFGNB) in Intensive Care Units (ICU) and their genetic potential to transmit diverse antibiotic resistance regardless of their ability to ferment glucose poses a major threat in hospitals. The complex interplay of clonal spread, persistence, transmission of resistance elements and cell-cell interaction leads to the difficulty in controlling infections caused by these multi drug-resistant strains. Among non-fermenting Gram-negative rods, the most clinically significant species Pseudomonas aeruginosa, Acinetobacter baumannii and Stenotrophomonas maltophilia are increasingly acquiring resistant to carbapenems. Carbapenems once considered as a backbone of treatment of life threatening infections appears to be broken as the resistance to carbapenems is on rise. To document the prevalence of carbapenem resistance in non-fermenting Gram-negative bacilli isolated from patients with respiratory tract infections in the ICU of Himalayan Institute of Medical Sciences, Dehradun. This is a cross-sectional study conducted in ICU patients between October 2015 to March 2016. A total of 366 lower respiratory tract samples were collected from 356 patients with clinical evidence of lower respiratory tract infections in form of Endotracheal (ET) aspirate, Tracheal Tube (TT) aspirate and Bronchoalveolar Lavage (BAL) specimen. Organism identification and the susceptibility testing was done by using an automated system VITEK 2. Out of 366 samples received 99 NFGNB were isolated and most common sample was ET aspirate sample 256 (64.5%). Acinetobacter baumannii was the most common NFGNB isolated 63 (63.63%) followed by Pseudomonas aeruginosa 25 (25.25%), Elizabethkingia meningoseptica seven (7.07%) and Strenotrophomonas maltophilia four (4.04%). We observed that 90.5% Acinetobacter baumannii were resistant to imipenem and 95.2% resistant to meropenem, Pseudomonas aeruginosa came out to be 52% resistant to imipenem and 56% resistant to meropenem while Stenotrophomonas maltophilia and Elizabethkingia meningoseptica were 100% resistant to carbapenems as they are intrinsically resistant to carbapenems. The resistance rate of carbapenems for NFGNB infections is very high in our study and variable in different regions. Overall carbapenem resistance is on rise. So, the infection control team and microbiologist needs to work together to determine the risk carried by multi drug resistant non-fermenting gram-negative infections and the resistance surveillance programs are mandatory to control these bacteria in ICU settings.

A Simple Technique to Improve Standard Nasotracheal Intubation

NTI is included in the ASA difficult airway algorithm. However, even with the assistance of a Magill forceps, it might be difficult to place the endotracheal (ET) tube in the trachea because of the angle at which the tube approaches the glottis opening and the inability to bend the tube secondary to the ET-tubes compliance. By placing a soft suction catheter thru the ET-tube, and placing the suction catheter into the trachea first and sliding the tube over the catheter this problem can be avoided. In addition, grabbing the suction catheter rather than the ET-tube, also prevents the rupturing of the ET-tube balloon by the Magill forceps.