Incidence Of Impingement Research Articles

Abstract No. : ABS1445: Comparative evaluation of two different endotrachealtubes for ease of orotracheal intubation in adults using flexible bronchoscope.

Background & Aims:Successful bronchoscopy does not mean successful intubation. Advancement of the ETT is blind and often difficult. Using the two-scope technique, we compared the polyvinylchloride tube with the flexometallic tube to determine which one was easier to railroad over the flexoscope.Methods:A radomised comparative study was conducted on 40 patients aged 18-65 years of American Society of Anesthesiologists physical status I-II, undergoing elective surgery under general anaesthesia. Patients with anticipated difficult airway, oral, head or neck surgery and pregnant women were excluded. A paediatric flexoscope was inserted through the nostril till the glottis was visible. An adult flexoscope was inserted till carina for orotracheal intubation and railroading of the endotracheal tube was done under vision of the paediatric flexoscope. Incidence and site of impingement were noted. Manoeuvres used to relieve impingement were jaw lift, withdrawal and 90° anti-clockwise tube rotation. Intubation time was also noted.Results:The overall incidence of impingement was 25% (10/40). Incidence of impingement was 35% (7/20) in polyvinylchloride group and 15% (3/20) in the flexometallic group (p>0.05). The 10% difference in impingement rates between the two groups was statistically non-significant. The site of impingement was at right arytenoids in 90% (9/10) cases. 90° anti-clockwise rotation relieved impingement in all cases where it was used (9/9). There was no significant difference in the time taken for intubation with the PVC and flexometallic tubes.Conclusion:Polyvinylchloride and flexometallic tubes are comparable in terms of ease of orotracheal intubation using a flexoscope. The commonest site of obstruction to the advancement of endotracheal tube is the right arytenoid. The 90° anticlockwise rotational-manoeuvre relieved impingement.GroupImpingementTotal NoYesPolyvinylchloride Count13720 %within Group65.0%35.0%100.0%Flexometallic Count17320 %within Group85.0%15.0%100.0%Total Count301040 %within Group75.0%25.0%100.0%

Tracheal intubation with King Vision video laryngoscope in patients with cervical spine instability-Comparison of straight versus curved reinforced endotracheal tubes.

Background and Aims:King Vision video laryngoscope is commonly used to facilitate intubation in corrective surgery for cervical spine instability patients due to less manipulation. Curved and straight reinforced tracheal tubes are regularly used in this surgery as neck of the patient is likely to be flexed. We aimed to compare intubation characteristics between the curved and straight reinforced tubes through King Vision video laryngoscope in patients to be operated for cervical spine instability with the primary objective being intubation time.Methods:Sixty patients undergoing cervical spine surgery were enroled in this prospective randomised comparative clinical study. All were intubated after applying manual in-line stabilisation of the neck, using either curved (group C) or straight (group S) reinforced endotracheal tubes through King Vision video laryngoscope. The intubation time, number of attempts, incidence of tube impingement with arytenoids/aryepiglottic folds, optimisation manoeuvres required and complications were observed. Unpaired ‘t’ test and Chi-square test were used to analyse the data using MedCalc software, version 12.5.Results:Time taken for intubation was shorter with curved compared to straight reinforced tube (16.24 ± 3.09 vs. 29.08 ± 5.48 seconds, P < 0.0001) The first attempt success rate was higher using curved than straight reinforced tube (93.3% vs. 70%, P = 0.02). Incidences of impingement with arytenoids/ aryepiglottic folds and optimisation manoeuvres required more with the straight reinforced tube.Conclusion:The intubation was fast and with higher first attempt success rate with curved than with straight reinforced tube through King Vision videolaryngoscope when used in patients with cervical spine instability.

Analysis of Impingement between Patella Bone and Bearing Post in Cruciate-Substituting High-Flexion Total Knee Arthroplasty.

BackgroundWe investigated the causes of impingement between the patella bone and the bearing post during high flexion in cruciate-substituting total knee arthroplasty and proposed a treatment strategy.MethodsThis prospective cohort study included 218 cases that had undergone cruciate-substituting total knee arthroplasty from February 2014 to January 2015; a single surgeon performed the operation using the same method without patellar resurfacing in all patients.Results In these patients, the occurrence of impingement was determined by performing more than 120° high knee flexion after inserting a bearing perioperatively. The incidence of impingement was significantly associated with bearing design, femoral implant size, patella bone length, and patella inferior pole angle (p < 0.05). The impingement was resolved by resection of the lower articular side of the patella bone.ConclusionsIn the cruciate-substituting high-flexion total knee arthroplasty, impingement between the patella bone and bearing post was more common in patients with mobile bearing, small-size femoral component, and a long patella or a large inferior pole angle. In cases of intraoperative impingement between the patella bone and the bearing post, resection in the lower portion of the patella prevented impingement of the bearing with soft tissue or the patella by widening the space between the patella and the bearing post, which in turn prevented postoperative reduction in range of motion.

Tracheal intubation with the AirwayScope™ videolaryngoscope using straight vs curved reinforced tubes

To the Editor, The AirwayScope (AWS-S100; IMI Co., LTD., Koshigaya Saitama, Japan) is proposed as an alternative to the classical Macintosh laryngoscope for tracheal intubation in patients with cervical spine instability and/or neck stiffness, because it offers a better laryngeal view with less cervical spine movement. Its introducer, the INTLOCK, gives the straight reinforced tube a downward orientation, whereas the curved tube points upwards. Therefore, intubation difficulties may be more frequent with the straight tube because of more likely impingement with the arytenoids (Fig. 1). We compared straight and curved reinforced endotracheal tubes in terms of intubation success rate, delay of intubation, incidence of impingement with the arytenoids, and postoperative sore throat and hoarseness. After obtaining approval from the Research Ethics Committee of Wakayama Medical University and written informed patient consent, 55 patients (45–84 yr) American Society of Anesthesiologists’ physical status I–III undergoing lumbar spine surgery had their tracheal intubation performed with an AWS using a tube size 7.5 for females (F) and 8.0 for males (M). Patients were assigned to the curved group (curved reinforced tube; Covidien, Mansfield, MA, USA), n = 25, M/F = 14/11, or to the straight group (straight reinforced tube; Fuji Systems Co., Bunkyo-ku, Tokyo, Japan), n = 30, M/F = 14/16. If intubation did not succeed at the first attempt, another insertion was allowed by adjusting the AWS direction upward. Twenty-four hours after surgery, severity of sore throat and hoarseness were graded. Sample size calculation was performed using the time from laryngeal view to intubation as the primary end point. Twenty-five patients were needed for an 89% power to detect changes of 4.8 sec at a significance level of 0.05; standard deviation (SD) = 5.2. Statistical analysis was performed using the Mann–Whitney U test or the v test. Patients in both groups had similar characteristics, including sex ratio, age, body mass index, Mallampati score, and duration of anesthesia. The intubation success rate was greater in the curved group than in the straight group (100% vs 83.3%, respectively; P 0.05). When failure of tracheal intubation occurred in the straight group, it was due to the arytenoid cartilages interfering with the tube advancement and not due to an inadequate view of the larynx. The time from laryngeal view to intubation lasted longer in the straight group than in the curved group (11.1 ± 5.2 sec vs 6.3 ± 4.7 sec, respectively; mean ± SD; P 0.05), whereas the time until the glottic view did not differ between groups (10.2 ± 7.0 sec vs 9.8 ± 5.9 sec, respectively). These results suggest that intubation delay in the straight group was not due to the inadequate laryngeal view. The number of insertion attempts was greater in the straight group than in the curved group (2.4 ± 1.4 attempts vs 1.2 ± 0.5 attempts, respectively; P 0.05), reflecting the need for more upward adjustments of the introducer tip T. Minonishi, MD H. Kinoshita, MD, PhD (&) K. Tange, MD Y. Hatano, MD, PhD Wakayama Medical University, Wakayama, Japan e-mail: hkinoshi@nike.eonet.ne.jp; hkinoshi@wakayama-med.ac.jp

The EndoFlex® Tube Enhances Navigability Through the Nasal Cavity During Nasotracheal Intubation

To the Editor: During nasotracheal intubation, the distal tip of the endotracheal tube (ETT) is inserted from the naris into the oropharynx and can impinge on the posterior wall of the nasopharynx, where the nasal passage curves perpendicularly. If excess force is applied, the ETT tip may perforate the retropharyngeal mucosa and, in rare cases, be inserted into the retropharyngeal space. Retropharyngeal laceration is a serious complication of nasotracheal intubation.1 Therefore, a number of methods have been reported to enhance the navigability of ETTs.2–4 The EndoFlex® tube (Merlyn Associates, Tustin, CA) is equipped with a distal-tip flexing mechanism.5 By pulling the friction lock upward, the distal tip of the tube is flexed anteriorly. Conceivably, anterior flexion of the distal tip can be easily adjusted to follow the anatomical curve of the nasopharynx. We compared the EndoFlex tube and the standard ETT (Portex® Blue Line Tracheal Tube) with regard to navigability through the nasal passage. The Clinical Ethical Committee at our hospital approved the study protocol, and informed consent was obtained from all patients. Sixty patients, aged 17–77 yr, scheduled to undergo elective oral surgery, were enrolled in the study. Patients with a history of nasal surgery, trauma, or recurrent epistaxis were excluded. Anesthesia was induced with thiopental (4–5 mg · kg−1) or propofol (1–2 mg · kg−1) and vecuronium (0.1 mg · kg−1) was IV administered. After the nasal cavity was examined using cotton swabs soaked with a vasoconstrictor,6 either the Portex tube (Portex tube group; n = 30) or the EndoFlex tube (EndoFlex tube group; n = 30) was randomly chosen and then gently inserted into the nasal cavity. The navigability of the tube on the first attempt was defined as either smooth or impinged.3,4 Data were analyzed by the χ2 test. A P value <0.05 was considered statistically significant. The ETT was judged to have impinged navigability in 13 of 30 patients in the Portex tube group. In these patients, the ETT was rotated counterclockwise and a bent stylet was used on the second or third attempt. Severe epistaxis impeding intubation was observed in one patient. In contrast, in all 30 patients in the EndoFlex tube group, ETT navigability was smooth, no repeated attempts were required, and no severe epistaxis occurred. The incidence of impingement was significantly different between these two groups (P < 0.001). These results suggest that the anteriorly flexed tip of the EndoFlex tube can improve navigability through the nasal passage without impinging on the posterior wall of the nasopharynx (Figure 1). Manipulating the friction lock of the EndoFlex tube facilitates reliable advancement of the ETT tip through the nasal cavity into the oropharynx and may reduce the incidence of retropharyngeal injuries.Figure 1.: Placement of the EndoFlex® tube in the nasopharynx. The distal tip of the tube can be adjusted to follow the anatomical curve of the nasopharynx by pulling the friction lock upward.Kazuna Sugiyama, DDS, PhD Naoki Takahashi, DDS, PhD Atsushi Kohjitani, DDS, PhD Department of Dental Anesthesiology Kagoshima University Graduate School of Medical and Dental Sciences Sakuragaoka, Kagoshima Japan [email protected]

Randomized, controlled trial of the double setup tracheal tube during fibreoptic orotracheal intubation under general anaesthesia

Impingement of the tracheal tube (ETT) on upper airway structures during railroading over the fibreoptic bronchoscope (FOB) occurs commonly. Potential complications of impingement include prolonged intubation time, leading to arterial desaturation, failed intubation and laryngeal trauma. The objective of this randomized, controlled trial was to assess the effect of the double setup ETT (a paediatric ETT is placed inside an adult ETT) on the incidence of impingement during orotracheal fibreoptic intubation. Two hundred patients were randomized to have a single ETT or double setup ETT. After induction of anaesthesia, fibreoptic orotracheal intubation was performed. The degree of impingement of the ETT during advancement over the FOB was assessed using a standardized scoring system based on the manoeuvres required to overcome the impingement. The incidence of impingement was lower using the double setup ETT compared with the single ETT (18 vs 93%, P<0.001). The double setup ETT also reduced the incidence of impingement requiring more than a simple 90 degrees counterclockwise rotation to achieve intubation (3 vs 14%, P=0.01) and reduced the median intubation time (31 vs 35 s, P=0.046). The double setup ETT is effective in reducing ETT impingement and in reducing intubation time. We did not find an association between ETT impingement and arterial desaturation.

Observations on the direction of wear in Charnley sockets retrieved at revision

The direction of wear in the acetabular socket has implications for the amount of debris that is generated during movement, for the magnitude of eccentric loading and for the incidence of impingement of the neck. We observed the direction of penetration with respect to a global co-ordinate system in 84 acetabular components retrieved at reoperation. The mean direction of wear relative to the open face of the sockets was found to be 37° with a range from 0° to 87°. For those values determined using the inclination of the socket on the prerevision radiograph, the mean direction of penetration in the coronal plane had a lateral, rather than a medial, component. The mean angle was 84° (SD 17°) with respect to the horizontal. The angle of penetration was found to correlate significantly with the depth, in that the lateral component became larger as the wear progressed. There was also a significant correlation between the rate of penetration and the direction of wear. Despite the theoretical advantage of penetration in the superolateral direction, i.e., along the margin of the socket, in reducing the probability of impingement of the neck, no significant correlation was seen between the angle of penetration and the period of use in vivo. This may suggest that impingement of the femoral neck on the rim of the socket may not be the dominant factor in loosening of the socket but can still be important in a few cases.