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Application of a flexible lightwand during percutaneous dilatational tracheotomy
Journal of Critical Care 41 (2017) 320–321
Contents lists available at ScienceDirect
Journal of Critical Care journal homepage: www.jccjournal.org
Application of a flexible lightwand during percutaneous dilatational tracheotomy Keywords: Lightwand Percutaneous dilatational tracheotomy Incision determination
To the Editor: The recent article by Zhao and colleagues [1] using a flexible lightwand to guide endotracheal tube (ETT) withdrawal and incision site determination during the percutaneous dilatational tracheotomy (PDT) in a randomized controlled study was of great interest. They show that this method compared with the traditional technique can effectively obtain precise ETT repositioning and provide incision site confirmation with less intra- and postoperative complications. Other than the limitations described in the discussion, however, we noted several issues of this study that need to be clarified and discussed. First, the authors did not clearly describe the manufacturer's details of the flexible lightwand used in this study. It is unclear whether this flexible lightwand is a registered medical device and how interested authors can purchase this device. Such information is useful for others who would like to try the PDT with this device. Moreover, the readers were not provided with details of the flexible lightwand, especially its outer diameter. According to Fig. 2 provided by authors, the outer diameter of the flexible lightwand should be N4.0 mm. We are concerned that when such thick flexible lightwand is inserted into the ETT to reposition the ETT and confirm the incision site, ventilation resistance will be significantly increased with adverse outcomes, especially for critical ill patients requiring a PDT [2]. Second, the authors stated that the distance between ETT tip and cuff root was 3 finger widths (about 4.8 cm). However, the size and manufacturer of ETT used in this study were not provided. It must be emphasized that the distance between ETT tip and cuff root is significantly different among ETTs of various sizes from same manufacturer and among same size ETTs from various manufacturers [3]. Thus, the findings of this study may be not meaningfully extrapolated to other ETTs besides that used in this study. Third, it is generally recommended that during intubation, the ETT tip is passed through the glottis, stopping 2 cm after the cuff completely passes the glottis; alternatively, when the external tube markings of 22 to 24 cm are at the upper incisors, the tube tip is at the midtrachea [4]. In this study, for Group W patients, the
0883-9441/© 2017 Elsevier Inc. All rights reserved.
ETT was withdrawn to a depth at the upper incisors of 17 cm in males and 15 cm in females, suggesting that the ETT tip has been at the level of the cricothyroid membrane. However, for Group L patients, the ETT was withdrawn until the cuff root was located at the level of the thyroid cartilage. The incidences of inadvertent extubation, ETT puncture and cuff rupture were significantly higher in the Group W compared to the Group L. In the results, the readers were not provided with the tube depth after withdrawal of ETT in the Group L. Is a higher incidence of complications in the Group W attributed to a more withdrawal of ETT? If so, we argue that more ETT puncture and cuff rupture events in the Group W cannot occur as the ETT tip is above the incision site. Furthermore, it was unclear whether head and neck position of patients during PDT was comparable with the two groups. The available evidence shows that head and neck extension, rotation and flexion can result in significant cephalad and caudal ETT movements and unpredictable tube displacements [5]. Fourth, in discussion, the authors stated that compared with the fiberoptic bronchoscope (FOB)-based technique, the flexible lightwand-based method reduces the time of ventilation interruption and may allow for a more precise determination of ETT location. Because this study did not compare the two techniques, this is evidently a subjective assumption without evidence. In fact, as a blind technique, the authors cannot provide that the flexible lightwand method provides a precise withdrawal of ETT and an accurate determination of incision site. The most significant advantage of FOB-based technique over flexible lightwand method is that the FOB can convert the ‘blind’ airway procedure into the operation under visual control. The recent evidence shows that the relation of ETT tip with the glottis, tracheal rings or carina can easy be determined by the FOB inserted into ETT [6]. Furthermore, combined PDT with FOB is a time-saving, easy-to-operate technique with few complications and can deal with the problems of tracheal wall injury or perforation, tracheoesophageal fistula, and hypoxia [7]. Finally, as a randomized controlled design, the readers were not provided with sample size calculation, though it is crucial to prevent type I and type II statistical errors [8]. We believe that addressing the above issues would further clarify the transparency of this study and improve interpretation of the findings of this study. Acknowledgement All the authors have no financial support and potential conflicts of interest for this work.
Letter / Journal of Critical Care 41 (2017) 320–321
Hui-Xian Li, MD Fu-Shan Xue, MD* Ya-Yang Liu, MD Gui-Zhen Yang, MD Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China ⁎Corresponding author at: Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 33 Ba-Da-Chu Road, Shi-Jing-Shan District, Beijing 100144, China. E-mail addresses: [email protected], [email protected]. http://dx.doi.org/10.1016/j.jcrc.2017.07.037 References [1] Zhao Z, Pan S, Wang D, Wang C, Li Z. Application of a flexible lightwand in percutaneous dilatational tracheotomy. J Crit Care 2017;42:25–9. [2] Lawson RW, Peters JI, Shelledy DC. Effects of fiberoptic bronchoscopy during mechanical ventilation in a lung model. Chest 2000;118:824–31.
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[3] Weiss M, Dullenkopf A, Gysin C, Dillier CM, Gerber AC. Shortcomings of cuffed paediatric tracheal tubes. Br J Anaesth 2004;92:78–88. [4] Berry JM. Conventional (laryngoscopic) orotracheal and nasotracheal intubation (single-lumen tube). In: Hagberg CA, editor. Benumof's airway management: principles and practice. 2nd edn. St Louis, MO: Mosby; 2007. p. 390–1. [5] Tailleur R, Bathory I, Dolci M, Frascarolo P, Kern C, Schoettker P. Endotracheal tube displacement during head and neck movements. Observational clinical trial. J Clin Anesth 2016;32:54–8. [6] Cherng CH, Wong CS, Hsu CH, Ho ST. Airway length in adults: estimation of the optimal endotracheal tube length for orotracheal intubation. J Clin Anesth 2002;14: 271–4. [7] Zhang H, Xu Y, Li H, Zhang Y, Cui L, Zhao L, et al. Application of modified percutaneous rotating dilative tracheostomy with fiberoptic bronchoscope in critical patients of ICU: a control study for four kinds of tracheostomy [article in Chinese]. Zhonghua Wei Zhong Bing Ji Jiu Yi Xue, 29; 2017 61–5. [8] Abdulatif M, Mukhtar A, Obayah G. Pitfalls in reporting sample size calculation in randomized controlled trials published in leading anaesthesia journals: a systematic review. Br J Anaesth 2015;115:699–707.
Contents lists available at ScienceDirect
Journal of Critical Care journal homepage: www.jccjournal.org
Application of a flexible lightwand during percutaneous dilatational tracheotomy Keywords: Lightwand Percutaneous dilatational tracheotomy Incision determination
To the Editor: The recent article by Zhao and colleagues [1] using a flexible lightwand to guide endotracheal tube (ETT) withdrawal and incision site determination during the percutaneous dilatational tracheotomy (PDT) in a randomized controlled study was of great interest. They show that this method compared with the traditional technique can effectively obtain precise ETT repositioning and provide incision site confirmation with less intra- and postoperative complications. Other than the limitations described in the discussion, however, we noted several issues of this study that need to be clarified and discussed. First, the authors did not clearly describe the manufacturer's details of the flexible lightwand used in this study. It is unclear whether this flexible lightwand is a registered medical device and how interested authors can purchase this device. Such information is useful for others who would like to try the PDT with this device. Moreover, the readers were not provided with details of the flexible lightwand, especially its outer diameter. According to Fig. 2 provided by authors, the outer diameter of the flexible lightwand should be N4.0 mm. We are concerned that when such thick flexible lightwand is inserted into the ETT to reposition the ETT and confirm the incision site, ventilation resistance will be significantly increased with adverse outcomes, especially for critical ill patients requiring a PDT [2]. Second, the authors stated that the distance between ETT tip and cuff root was 3 finger widths (about 4.8 cm). However, the size and manufacturer of ETT used in this study were not provided. It must be emphasized that the distance between ETT tip and cuff root is significantly different among ETTs of various sizes from same manufacturer and among same size ETTs from various manufacturers [3]. Thus, the findings of this study may be not meaningfully extrapolated to other ETTs besides that used in this study. Third, it is generally recommended that during intubation, the ETT tip is passed through the glottis, stopping 2 cm after the cuff completely passes the glottis; alternatively, when the external tube markings of 22 to 24 cm are at the upper incisors, the tube tip is at the midtrachea [4]. In this study, for Group W patients, the
0883-9441/© 2017 Elsevier Inc. All rights reserved.
ETT was withdrawn to a depth at the upper incisors of 17 cm in males and 15 cm in females, suggesting that the ETT tip has been at the level of the cricothyroid membrane. However, for Group L patients, the ETT was withdrawn until the cuff root was located at the level of the thyroid cartilage. The incidences of inadvertent extubation, ETT puncture and cuff rupture were significantly higher in the Group W compared to the Group L. In the results, the readers were not provided with the tube depth after withdrawal of ETT in the Group L. Is a higher incidence of complications in the Group W attributed to a more withdrawal of ETT? If so, we argue that more ETT puncture and cuff rupture events in the Group W cannot occur as the ETT tip is above the incision site. Furthermore, it was unclear whether head and neck position of patients during PDT was comparable with the two groups. The available evidence shows that head and neck extension, rotation and flexion can result in significant cephalad and caudal ETT movements and unpredictable tube displacements [5]. Fourth, in discussion, the authors stated that compared with the fiberoptic bronchoscope (FOB)-based technique, the flexible lightwand-based method reduces the time of ventilation interruption and may allow for a more precise determination of ETT location. Because this study did not compare the two techniques, this is evidently a subjective assumption without evidence. In fact, as a blind technique, the authors cannot provide that the flexible lightwand method provides a precise withdrawal of ETT and an accurate determination of incision site. The most significant advantage of FOB-based technique over flexible lightwand method is that the FOB can convert the ‘blind’ airway procedure into the operation under visual control. The recent evidence shows that the relation of ETT tip with the glottis, tracheal rings or carina can easy be determined by the FOB inserted into ETT [6]. Furthermore, combined PDT with FOB is a time-saving, easy-to-operate technique with few complications and can deal with the problems of tracheal wall injury or perforation, tracheoesophageal fistula, and hypoxia [7]. Finally, as a randomized controlled design, the readers were not provided with sample size calculation, though it is crucial to prevent type I and type II statistical errors [8]. We believe that addressing the above issues would further clarify the transparency of this study and improve interpretation of the findings of this study. Acknowledgement All the authors have no financial support and potential conflicts of interest for this work.
Letter / Journal of Critical Care 41 (2017) 320–321
Hui-Xian Li, MD Fu-Shan Xue, MD* Ya-Yang Liu, MD Gui-Zhen Yang, MD Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China ⁎Corresponding author at: Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 33 Ba-Da-Chu Road, Shi-Jing-Shan District, Beijing 100144, China. E-mail addresses: [email protected], [email protected]. http://dx.doi.org/10.1016/j.jcrc.2017.07.037 References [1] Zhao Z, Pan S, Wang D, Wang C, Li Z. Application of a flexible lightwand in percutaneous dilatational tracheotomy. J Crit Care 2017;42:25–9. [2] Lawson RW, Peters JI, Shelledy DC. Effects of fiberoptic bronchoscopy during mechanical ventilation in a lung model. Chest 2000;118:824–31.
321
[3] Weiss M, Dullenkopf A, Gysin C, Dillier CM, Gerber AC. Shortcomings of cuffed paediatric tracheal tubes. Br J Anaesth 2004;92:78–88. [4] Berry JM. Conventional (laryngoscopic) orotracheal and nasotracheal intubation (single-lumen tube). In: Hagberg CA, editor. Benumof's airway management: principles and practice. 2nd edn. St Louis, MO: Mosby; 2007. p. 390–1. [5] Tailleur R, Bathory I, Dolci M, Frascarolo P, Kern C, Schoettker P. Endotracheal tube displacement during head and neck movements. Observational clinical trial. J Clin Anesth 2016;32:54–8. [6] Cherng CH, Wong CS, Hsu CH, Ho ST. Airway length in adults: estimation of the optimal endotracheal tube length for orotracheal intubation. J Clin Anesth 2002;14: 271–4. [7] Zhang H, Xu Y, Li H, Zhang Y, Cui L, Zhao L, et al. Application of modified percutaneous rotating dilative tracheostomy with fiberoptic bronchoscope in critical patients of ICU: a control study for four kinds of tracheostomy [article in Chinese]. Zhonghua Wei Zhong Bing Ji Jiu Yi Xue, 29; 2017 61–5. [8] Abdulatif M, Mukhtar A, Obayah G. Pitfalls in reporting sample size calculation in randomized controlled trials published in leading anaesthesia journals: a systematic review. Br J Anaesth 2015;115:699–707.