Vasovagal Pre-Syncope Induced by Epidural Electrical Stimulation Test: A Rare Case Report in a 61-Year-Old Woman Undergoing Ventral Hernia Repair.

BACKGROUND Thoracic epidural analgesia is a commonly applied technique for perioperative pain management in major thoraco-abdominal surgery, but is complicated by high failure rates. The epidural electrical stimulation test (EEST) or "Tsui test" is a safe and effective method whereby low electrical current is used to confirm correct epidural catheter position and decrease the variability in analgesic effectiveness of the neuraxial technique. CASE REPORT We present the case of a 61-year-old woman with no prior cardiac or pulmonary comorbidities who was scheduled to undergo a ventral and parastomal hernia repair with component separation. The patient was offered a low thoracic epidural for perioperative analgesia. Technical aspects of the siting of the epidural catheter were uneventful and a confirmatory Tsui test was planned. At the initiation of electrical stimulation via the epidural catheter to confirm optimal catheter positioning, the patient experienced symptomatic bradycardia and hemodynamic instability that persisted despite terminating the electrical stimulation, and required pharmacologic intervention. CONCLUSIONS This report describes a rare case of vasovagal pre-syncope associated with the EEST or Tsui test. Although vasovagal reactions can be commonly associated with neuraxial procedures due to augmented venous return or severe emotional stress, we raise the possibility that through direct electrical stimulation in the epidural space, the EEST may have the potential to trigger such a physiologic response.

Evaluating the Impact of Assessment Metrics for Simulated Central Venous Catheterization Training.

INTRODUCTION: Performance assessment and feedback are critical factors in successful medical simulation-based training. The Dynamic Haptic Robotic Trainer (DHRT) allows residents to practice ultrasound-guided needle insertions during simulated central venous catheterization (CVC) procedures while providing detailed feedback and assessment. A study was performed to examine the effectiveness of the DHRT in training the important skills of needle tip tracking and aspiration and how these skills impact procedural complications in simulated CVC. METHODS: The DHRT data were collected for 163 residents at 2 hospitals for 6 simulated needle insertions. Users were given automated feedback on 5 performance metrics, which measure aspiration rate, arterial punctures, punctures through and through the vein, loss of access to the vein, and successful access to the vein. Aspiration rates and tip tracking rates were analyzed to determine their significance in preventing CVC complications and improving performance. RESULTS: Tip tracking rates higher than 40% were 2.3 times more likely to result in successful venous access than rates less than 10%. Similarly, aspiration rates higher than 80% were 2.6 times more likely to result in successful venous access than rates less than 10%. Proper tip tracking and aspiration both reduced mechanical complications. Resident performance improved for all metrics except tip tracking. CONCLUSIONS: Proper tip tracking and aspiration both reduced complications and increased the likelihood of success. However, the skill of tip tracking was not effectively learned through practice without feedback. Therefore, ultrasound-guided needle-based procedures, including CVC, can be improved by providing specific feedback to users on their ultrasound usage to track needle insertions.

Resistance to local anesthesia in people with the Ehlers-Danlos Syndromes presenting for dental surgery.

BACKGROUND: People with the Ehlers-Danlos Syndromes (EDS), a group of heritable disorders of connective tissue, often report experiencing dental procedure pain despite local anesthetic (LA) use. Clinicians have been uncertain how to interpret this apparent LA resistance, as comparison of EDS and non-EDS patient experience is limited to anecdotal evidence and small case series. The primary goal of this hypothesis-generating study was to investigate the recalled adequacy of pain prevention with LA administered during dental procedures in a large cohort of people with and without EDS. A secondary exploratory aim asked people with EDS to recall comparative LA experiences. METHODS: We administered an online survey through various social media platforms to people with EDS and their friends without EDS, asking about past dental procedures, LA exposures, and the adequacy of procedure pain prevention. Among EDS respondents who both received LA and recalled the specific LA used, we compared agent-specific pain prevention for lidocaine, procaine, bupivacaine, mepivacaine, and articaine. RESULTS: Among the 980 EDS respondents who had undergone a dental procedure LA, 88% (n = 860) recalled inadequate pain prevention. Among 249 non EDS respondents only 33% (n = 83) recalled inadequate pain prevention (P < 0.001 compared to EDS respondents). The agent with the highest EDS-respondent reported success rate was articaine (30%), followed by bupivacaine (25%), and mepivacaine (22%). CONCLUSIONS: EDS survey respondents reported nearly three times the rate of LA non-response compared to non-EDS respondents, suggesting that LAs were less effective in preventing their pain associated with routine office dental procedures.

Impact of the NaV1.8 variant, A1073V, on post-sigmoidectomy pain and electrophysiological function in rat sympathetic neurons.

NaV1.8 channels play a crucial role in regulating the action potential in nociceptive neurons. A single nucleotide polymorphism in the human NaV1.8 gene SCN10A, A1073V (rs6795970, G>A), has been linked to the diminution of mechanical pain sensation as well as cardiac conduction abnormalities. Furthermore, studies have suggested that this polymorphism may result in a "loss-of-function" phenotype. In the present study, we performed genomic analysis of A1073V polymorphism presence in a cohort of patients undergoing sigmoid colectomy who provided information regarding perioperative pain and analgesic use. Homozygous carriers reported significantly reduced severity in postoperative abdominal pain compared with heterozygous and wild-type carriers. Homozygotes also trended toward using less analgesic/opiates during the postoperative period. We also heterologously expressed the wild-type and A1073V variant in rat superior cervical ganglion neurons. Electrophysiological testing demonstrated that the mutant NaV1.8 channels activated at more depolarized potentials compared with wild-type channels. Our study revealed that postoperative abdominal pain is diminished in homozygous carriers of A1073V and that this is likely due to reduced transmission of action potentials in nociceptive neurons. Our findings reinforce the importance of NaV1.8 and the A1073V polymorphism to pain perception. This information could be used to develop new predictive tools to optimize patient pain experience and analgesic use in the perioperative setting.NEW & NOTEWORTHY We present evidence that in a cohort of patients undergoing sigmoid colectomy, those homozygous for the NaV1.8 polymorphism (rs6795970) reported significantly lower abdominal pain scores than individuals with the homozygous wild-type or heterozygous genotype. In vitro electrophysiological recordings also suggest that the mutant NaV1.8 channel activates at more depolarizing potentials than the wild-type Na+ channel, characteristic of hypoactivity. This is the first report linking the rs6795970 mutation with postoperative abdominal pain in humans.

Simulating Ultrasound Tissue Deformation Using Inverse Mapping.

Ultrasound guidance is used for a variety of surgical needle insertion procedures, but there is currently no standard for the teaching of ultrasound skills. Recently, computer ultrasound simulation has been introduced as an alternative teaching method to traditional manikin and cadaver training because of its ability to provide diverse scenario training, quantitative feedback, and objective assessment. Current computer ultrasound training simulation is limited in its ability to image tissue deformation caused by needle insertions, even though tissue deformation identification is a critical skill in performing an ultrasound-guided needle insertion. To fill this need for improved simulation, a novel method of simulating ultrasound tissue-needle deformation is proposed and evaluated. First, a cadaver study is conducted to obtain ultrasound video of a peripheral nerve block. Then, optical flow analysis is conducted on this video to characterize the tissue movement due to the needle insertion. Tissue movement is characterized into three zones of motion: tissue near the needle being pulled, and zones above and below the needle where the tissue rolls. The rolling zones were centered 1.34 mm above and below the needle and 4.53 mm behind the needle. Using this characterization, a vector field is generated mimicking these zones. This vector field is then applied to an ultrasound image using inverse mapping to simulate tissue movement. The resulting simulation can be processed at 3.1 frames per second. This methodology can be applied through future optimized graphical processing to allow for accurate real time needle tissue simulation.

Transmuscular quadratus lumborum versus lumbar plexus block for total hip arthroplasty: A retrospective propensity score matched cohort study.

BACKGROUND AND AIMS: Cadaveric studies have shown that injectate from transmuscular quadratus lumborum block (QLB) can spread to the lumbar plexus. Our aim was to compare analgesic efficacy of transmuscular QLB with lumbar plexus block (LPB) for patients undergoing total hip arthroplasty (THA). MATERIAL AND METHODS: Thirty patients receiving transmuscular QLB were propensity score matched with 30 patients receiving LPB for age, sex, ASA score, BMI, operative time, preoperative oxycodone, and intraoperative opioid use. The primary outcome was postoperative opioid consumption during the first 24 postoperative hours. Secondary outcomes included static pain scores at 0-12, 12-24, and 24-48 h intervals, opioid consumption at 0-12, 12-24, and 24-48 h intervals and the length of hospital stay. The incidence of severe adverse events was also compared. RESULTS: Opioid consumption (median [IQR]) in the first 24 h was similar between the transmuscular QLB and LPB patient groups-33.6 mg (22.9-48.5) versus 32.8 mg (24.8-58.3) intravenous morphine equivalents. There was no difference between groups in static pain scores or opioid consumption during any time interval up to 48 h postoperatively. Length of hospital stay (median [IQR]) was similar between the transmuscular QLB and LPB groups-55.6 h (53.7-60.3) versus 57.9 h (54.3-79.1). CONCLUSIONS: This study suggests that transmuscular QLB provides similar analgesia to LPB following THA. Prospective studies are needed to confirm this.

Pharmacogenomics of analgesics in anesthesia practice: A current update of literature.

The field of pharmacogenomics seeks to understand how an individual's unique gene sequence can affect their response to certain drugs. It is particularly relevant in anesthesia when the interindividual response to pain medication is essential. Codeine and tramadol are prodrugs metabolized by CYP2D6, polymorphisms of which can cause dangerous or even fatal levels of their metabolites, or decrease the level of metabolites to decrease their analgesic effect. Many other opioids are metabolized by CYP2D6 or CYP3A5, of which loss-of-function variants can cause dangerous levels of these drugs. The OCT1 transporter facilitates the movement of drugs into hepatocytes for metabolism, and variants of this transporter can increase serum levels of morphine and O-desmethyltramadol. Many NSAIDs are metabolized by CYP2C9, and there is concern that variants of this enzyme may lead to high serum levels of these drugs, causing gastrointestinal bleeding, however the data does not strongly support this. The ABCB1 gene encodes for P-glycoprotein which facilitates efflux of opioids away from their target receptors. The C3435T SNP may increase the concentration of opioids at target receptors, although the data is not conclusive. Catechol-O-Methyltransferase (COMT) is shown to indirectly upregulate opioid receptors. Certain haplotypes of COMT have been demonstrated to have an effect on opioid requirements. The OPRM1 gene codes for the mu-opioid receptor, and there is conflicting data regarding its effect on analgesia and opioid requirements. Overall, there is a fair amount of conflicting data in the above topics, suggesting that there is still a lot of research to be done on these topics, and that pain perception is multifactorial, likely including many common genetic variants.

Liposomal Bupivacaine Use in Transversus Abdominis Plane Blocks Reduces Pain and Postoperative Intravenous Opioid Requirement After Colorectal Surgery.

BACKGROUND: Enhanced recovery protocols frequently use multimodal postoperative analgesia to improve postoperative outcomes in patients undergoing colorectal surgery. OBJECTIVE: The purpose of this study was to evaluate liposomal bupivacaine use in transversus abdominis plane blocks on postoperative pain scores and opioid use after colorectal surgery. DESIGN: This was a retrospective cohort study comparing outcomes between patients receiving nonliposomal anesthetic (n = 104) and liposomal bupivacaine (n = 303) blocks. SETTINGS: The study was conducted at a single tertiary care center. PATIENTS: Patients included those identified within an institutional database as inpatients undergoing colorectal procedures between 2013 and 2015 who underwent transversus abdominis plane block for perioperative analgesia. MAIN OUTCOME MEASURES: The study measured postoperative pain scores and opioid requirements. RESULTS: Patients receiving liposomal bupivacaine had significantly lower pain scores for the first 24 to 36 postoperative hours. Pain scores were similar after 36 hours. The use of intravenous opioids among the liposomal bupivacaine group decreased by more than one third during the hospitalization (99.1 vs 64.5 mg; p = 0.040). The use of ketorolac was also decreased (49.0 vs 18.3 mg; p < 0.001). In subgroup analysis, the decrease in opioid use was observed between laparoscopic and robotic procedures but not with laparotomies. No significant differences were noted in the use of oral opioids, acetaminophen, or ibuprofen. Postoperative length of stay and total cost were decreased in the liposomal bupivacaine group but did not achieve statistical significance. LIMITATIONS: The study was limited by its retrospective, single-center design and heterogeneity of block administration. CONCLUSIONS: Attenuated pain scores observed with liposomal bupivacaine use were associated with significantly lower intravenous opioid and ketorolac use, suggesting that liposomal bupivacaine-containing transversus abdominis plane blocks are well aligned with the opioid-reducing goals of many enhanced recovery protocols.

The Erector Spinae Plane Block: A Novel Analgesic Technique in Thoracic Neuropathic Pain.

Thoracic neuropathic pain is a debilitating condition that is often poorly responsive to oral and topical pharmacotherapy. The benefit of interventional nerve block procedures is unclear due to a paucity of evidence and the invasiveness of the described techniques. In this report, we describe a novel interfascial plane block, the erector spinae plane (ESP) block, and its successful application in 2 cases of severe neuropathic pain (the first resulting from metastatic disease of the ribs, and the second from malunion of multiple rib fractures). In both cases, the ESP block also produced an extensive multidermatomal sensory block. Anatomical and radiological investigation in fresh cadavers indicates that its likely site of action is at the dorsal and ventral rami of the thoracic spinal nerves. The ESP block holds promise as a simple and safe technique for thoracic analgesia in both chronic neuropathic pain as well as acute postsurgical or posttraumatic pain.

Body Mass Index More Than 45 kg/m(2) as a Cutoff Point Is Associated With Dramatically Increased Postoperative Complications in Total Knee Arthroplasty and Total Hip Arthroplasty.

BACKGROUND: Higher body mass index (BMI) has been associated with postoperative complications in total knee arthroplasty (TKA) and total hip arthroplasty (THA). However, the association of incremental increases of BMI and its effects on postoperative complications has not been well studied. We hypothesize that there is a BMI cutoff at which there is a significant increase of the risk of postoperative complications. METHODS: We studied the American College of Surgeons National Surgical Quality Improvement Program from 2006 to 2013. The final cohort included 77,785 primary TKA and 49,475 primary THA subjects, respectively. Patients were separated into 7 groups based on BMI (18.5-24.9 kg/m(2), 25.0-29.9 kg/m(2), 30.0-34.9 kg/m(2), 35.0-39.9 kg/m(2), 40.0-44.9 kg/m(2), 45.0-49.9 kg/m(2), and >50.0 kg/m(2)). We analyzed data on five 30-day composite complication variables, including any complication, major complication, wound infection, systemic infection, and cardiac and/or pulmonary complication. RESULTS: The odds ratio for 4 (any complication, major complication, wound infection, and systemic infection) of 5 composite complications started to increase exponentially once BMI reached 45.0 kg/m(2) or higher in TKA. Similarly, the odds ratio in 3 (any complication, systemic infection, and wound infection) of 5 composite complications showed similar trends in THA patients. These findings were further confirmed with propensity score matching and entropy balancing. CONCLUSIONS: Our study suggested that there was a positive correlation between BMI and incidences of 30-day postoperative complications in both TKA and THA. The odds of complications increased dramatically once BMI reached 45.0 kg/m(2).

A Survey of Ultrasound Training in U.S. and Canadian Chronic Pain Fellowship Programs.

OBJECTIVE: To assess the current state of ultrasound training in U.S. and Canadian Chronic Pain Fellowship programs. DESIGN: U.S. as well as Canadian chronic pain fellowship programs were contacted via email and program directors were asked to complete a survey. The surveys were completed online using a questionnaire. SETTING: Questionnaire via email. PATIENTS: None. INTERVENTIONS: None. OUTCOME: To assess the current state of ultrasound training in U.S. and Canadian Chronic Pain Fellowship programs. MEASURES: Current teaching structure, types, and numbers of ultrasound-guided interventional pain procedures. RESULTS: Thirty-one responses (30.7%) from the 97 U.S. and four Canadian programs surveyed. Of the 31 programs that responded, 26 offered ultrasound training; five did not. These 31 programs averaged 4.1 fellows per year, majority 96.2% of the 26 programs taught ultrasound throughout the fellowship year. The type of ultrasound training varied, with the large majority 96.2% being patient based. Among 26 programs, 96.2% used ultrasound for peripheral nerve blocks, 76.9% used ultrasound for non-axial musculoskeletal injections, and 53.8% used ultrasound for axial nerve blocks. CONCLUSIONS: Chronic pain fellowships were teaching ultrasound-guided procedures to their fellows. The majority of the fellowships offered ultrasound training throughout the fellowship year. A majority of training was accomplished via hands-on experience with patients. Chronic pain fellows were receiving a majority of ultrasound training for peripheral nerve blocks, followed by nonaxial musculoskeletal blocks, with few axial nerve blocks being taught.

Osteopathic musculoskeletal examination and subarachnoid anesthetic administration in a patient with severe scoliosis.

Physicians primarily use palpation of anatomical landmarks to guide the placement of needles when administering neuraxial anesthetics. For patients with anatomical abnormalities such as scoliosis, it is also important for physicians to understand Fryette mechanics and spinal curvature anatomy, as well as preprocedural radiography and ultrasonography, to ensure accuracy in neuraxial anesthetic procedures. The authors report the case of a patient with severe scoliosis who required neuraxial anesthesia for total hip arthroplasty. Using palpation and imaging, his physicians were able to successfully administer a subarachnoid anesthetic injection on the first attempt. The authors discuss considerations for improving success rates of neuraxial anesthetic administration in these patients.

Infraclavicular brachial plexus block for regional anaesthesia of the lower arm.

BACKGROUND: Several approaches exist to produce local anaesthetic blockade of the brachial plexus. It is not clear which is the technique of choice for providing surgical anaesthesia of the lower arm, although infraclavicular blockade (ICB) has several purported advantages. We therefore performed a systematic review of ICB compared to the other brachial plexus blocks (BPBs). This review was originally published in 2010 and was updated in 2013. OBJECTIVES: The objective of this review was to evaluate the efficacy and safety of infraclavicular block (ICB) compared to other approaches to the brachial plexus in providing regional anaesthesia for surgery on the lower arm. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2013, Issue 5); MEDLINE (1966 to June 2013) via OvidSP; and EMBASE (1980 to June 2013) via OvidSP. We also searched conference proceedings (from 2004 to 2012) and the www.clinicaltrials.gov trials registry. The searches for the original review were performed in September 2008. SELECTION CRITERIA: We included any randomized controlled trials (RCTs) that compared ICB with other BPBs as the sole anaesthetic technique for surgery on the lower arm. DATA COLLECTION AND ANALYSIS: The primary outcome was adequate surgical anaesthesia within 30 minutes of block completion. Secondary outcomes included sensory block of individual nerves, tourniquet pain, onset time of sensory blockade, block performance time, block-associated pain and complications related to the block. MAIN RESULTS: In our original review we included 15 studies with 1020 participants and excluded two. In this updated review we included seven new studies and excluded six, bringing the total number of included studies to 22 and involving 1732 participants. The control group intervention was the axillary block in 14 studies, supraclavicular block in six studies, mid-humeral block in two studies, and parascalene block in one study. One study compared ICB to both axillary and supraclavicular blocks. Nine studies employed ultrasound-guided ICB. The risk of failed surgical anaesthesia 30 minutes after block completion was similar for ICB and all other BPBs (11.4% versus 12.9%, risk ratio (RR) 0.88, 95% CI 0.51 to 1.52, P = 0.64), but tourniquet pain was less likely with ICB (11.9% versus 18.0%; RR of experiencing tourniquet pain 0.66, 95% CI 0.47 to 0.92, P = 0.02). Subgroup analysis by method of nerve localization, and by control group intervention, did not show any statistically significant differences in the risk of failed surgical anaesthesia. However when compared to a single-injection axillary block, ICB was better at providing complete sensory block of the musculocutaneous nerve (RR for failure 0.46, 95% CI 0.27 to 0.60, P < 0.0001). ICB had a slightly longer sensory block onset time (mean difference (MD) 1.9 min, 95% CI 0.2 to 3.6, P = 0.03) but was faster to perform than multiple-injection axillary (MD -2.7 min, 95% CI -3.4 to -2.0, P < 0.00001) or mid-humeral (MD -4.8 min, 95% CI -6.0 to -3.6, P < 0.00001) blocks. AUTHORS' CONCLUSIONS: ICB is as safe and effective as any other BPBs, regardless of whether ultrasound or neurostimulation guidance is used. The advantages of ICB include a lower likelihood of tourniquet pain during surgery, more reliable blockade of the musculocutaneous nerve when compared to a single-injection axillary block, and a significantly shorter block performance time compared to multi-injection axillary and mid-humeral blocks.

The effects of anaesthetic agents on cortical mapping during neurosurgical procedures involving eloquent areas of the brain.

BACKGROUND: In patients presenting for surgical resection of lesions involving, or adjacent to, the functionally important eloquent cortical areas, it is vital to achieve complete or near complete resection of the pathology without damaging the healthy surrounding tissues.The eloquent areas that the surgeons are concerned with are the primary motor, premotor cortex, supplementary motor cortex and speech areas. If the lesions are within these regions surgeons could either take a biopsy or do a intracapsular decompression without damaging the mentioned areas to avoid postoperative dysfunction. If the lesions are adjacent to the above mentioned areas, the normal anatomy would get distorted. However, proper identification of the above mentioned areas would enable the surgeon to radically remove the tumours. Intraoperative mapping of the cortex with stimulating and recording electrodes is termed as electrophysiological (EP) mapping.The EP mapping of motor, sensory and language cortex is widely employed in the resection of lesions involving or adjacent to the eloquent areas. Both intravenous and inhalational agents are known to affect these EP mapping techniques. OBJECTIVES: The aim of this review was to evaluate the effect of anaesthetic agents on intra-operative EP mapping in patients undergoing neurosurgical procedures involving, or adjacent to, the functional areas of the cortex under general anaesthesia. SEARCH METHODS: We searched the Cochrane Epilepsy Group Specialized Register (7 March 2011), The Cochrane Central Register of Controlled Trials (CENTRAL issue 1 of 4, The Cochrane Library 2011), MEDLINE (Ovid, 1948 to February week 4, 2011), PsycINFO (EBSCOhost, 7 March 2011), and the National Research Register Archive and UK Clinical Research Network (7 March 2011). We also contacted other researchers in the field in an attempt to ascertain unpublished studies. SELECTION CRITERIA: We planned to include randomised and quasi randomised controlled trials irrespective of blinding in patients of any age or gender undergoing neurosurgery under general anaesthesia where cortical mapping was attempted to identify eloquent areas using either somatosensory evoked potentials (SSEPs), or direct cortical stimulation (DCS) triggered muscle motor evoked potentials (mMEPs), or both. We excluded patients from trials where the anaesthetic effects were evaluated during spinal cord surgery or where MEPs were recorded from modes other than direct cortical stimulation such as transcranial electrical stimulation (TcMEPs), MEPs derived from epidural electrodes (D waves) and magnetic stimulation and trials involving awake craniotomies or the asleep-awake-asleep technique during cortical mapping. DATA COLLECTION AND ANALYSIS: Two review authors planned to independently apply the inclusion criteria and extract data. MAIN RESULTS: No RCTs were found for this study population. AUTHORS' CONCLUSIONS: This review highlights the need for well-designed randomised controlled trials to assess the effect of anaesthetic agents on cortical mapping during neurosurgical procedures involving eloquent areas of the brain.

The effect of bronchoscope rotation on tracheal tube orientation at the glottic level in a mannequin.

PURPOSE: This study examined the effect of external fibreoptic bronchoscope (FOB) rotations on endotracheal tube (ETT) orientations at the glottic level. METHODS: Using a mannequin, a nasal FOB was inserted for image capture. A second FOB with a preloaded ETT taped to its top was inserted orally into mid-trachea. The FOB with the taped ETT was rotated as a unit in the axial plane to five different external angles (-90°, -45°, 0°, +45°, +90°). At each external rotation, the ETT was advanced into the trachea. The image of the ETT at the glottic level was captured. Endotracheal tube orientation was quantified according to the glottic zone faced by the ETT. The ETT orientations were compared amongst the five external FOB rotations using the Kruskal-Wallis Test, while the ETT orientations at -90°, -45°, +45°, and +90° FOB rotations were compared with 0° rotation using the Mann-Whitney U test. RESULTS: There was a significant difference in the ETT orientations amongst the five FOB rotations (P < 0.001). The ETT orientations at -90°, -45°, +45°, and +90° FOB rotations were different from the 0° rotation (P < 0.001 for all comparisons). A -90° FOB rotation was most effective in turning the ETT tip away from the right laryngeal structures and the interarytenoid tissue. CONCLUSION: With the ETT loaded on a FOB, rotation of the FOB prior to advancing the ETT is effective in changing the ETT orientation at the glottis. A -90° FOB rotation is most effective in turning the ETT tip away from the right laryngeal structures and interarytenoid tissue.