We thank Dr Desai [1] for his interest in our paper [2]. He raises some interesting points and we would like to clarify some of the interpretations. Our publication uses Bayesian statistics to evaluate six different local anaesthetics and combinations in terms of onset time for surgical anaesthesia. The league table referred to in the letter represents ‘credible intervals’, which differ from conventional confidence intervals commonly used when reporting trial outcomes. Credible intervals generated via Bayesian analysis incorporate problem-specific contextual information from the prior distribution, whereas confidence intervals are basedonly on thedata available. Credible intervals, although they may have overlaps, are used to generate a conservative probability rank order. This is reported as a ‘rankogram’, which essentially reports the probability of a treatment being best (rather than stating that the treatment is the best, as in conventional frequentist statistics). As Dr Desai suggests, it is difficult to grade the efficacy of one treatment being better than the other for ‘incidence of hypotension’ solely based on the values in the league table because there were only minor differences (or significant overlap) in the reported credible intervals. The result of this minor difference is actually apparent in the rankogram as the probability of being the best treatment is distributed with only a small difference across all the interventions evaluated (dark blue) (Fig. 1). The reported preference order in our paper is

Background: Use of electronic medical record systems has increased in the recent years. Epic is one such system gaining popularity in the USA. Epic is a private company, which invented the electronic documentation system adopted in our hospital. In spite of many presumed advantages, its use is not critically analyzed. Some of the perceived advantages are increased efficiency and protection against litigation as a result of accurate documentation. Materials and Methods: In this study, retrospective data of 305 patients who underwent endoscopic retrograde cholangiopancreatography (wherein electronic charting was used - "Epic group") were compared with 288 patients who underwent the same procedure with documentation saved on a paper chart ("paper group"). Time of various events involved in the procedure such as anesthesia start, endoscope insertion, endoscope removal, and transfer to the postanesthesia care unit were routinely documented. From this data, the various time durations were calculated. Results: Both "anesthesia start to scope insertion" times and "scope removal to transfer" times were significantly less in the Epic group compared to the paper group. Use of Epic system led to a saving of 4 min of procedure time per patient. However, the mean oxygen saturation was significantly less in the Epic group. Conclusion: In spite of perceived advantages of Epic documentation system, significant hurdles remain with its use. Although the system allows seamless flow of patients, failure to remove all artifacts can lead to errors and become a source of potential litigation hazard.

Editor—A Montgomery tube (MT) is a silicone tube that is used to stent the airway open after laryngeo-tracheal stenosis.1Prasanna Kumar S Ravikumar A Senthil K Somu L Nazrin MI Role of Montgomery T-tube stent for laryngotracheal stenosis.Auris Nasus Larynx. 2014; 41: 195-200Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar Owing to its infrequent use, working knowledge of the present-day anaesthesiologists is extremely limited. The scarcely available literature just sums up possible methods of securing airway in these patients for intraoperative positive pressure ventilation.2Agrawal S Payal YS Sharma JP Meher R Varshney S Montgomery T-tube: anesthetic management.J Clin Anesth. 2007; 19: 135-137Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar 3Guha A Mostafa SM Kendall JB The Montgomery T-tube: anaesthetic problems and solutions.Br J Anaesth. 2001; 87: 787-790Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar However, like any other airway devices [tracheal tube (TT) or tracheostomy tube], its preoperative evaluation is critical. The lack of first-hand experience and available literature often leads to underestimation of possible complications and thus preoperative planning fails to foresee associated hazards. We present a child with an MT who underwent general anaesthesia and was subject to significant preventable morbidity as a result of undiagnosed obstruction in the upper limb of the MT. A 4-yr-old male child developed tracheal stenosis 6 months ago for which an MT was inserted to alleviate the stridor in order to stent the subglottic tracheal narrowing. Presently, bronchoscopic assessment of the upper airway was planned under general anaesthesia. During pre-anaesthesia workup, the child/parents reported no complication related to the MT or any breathing difficulty. An i.v. line was secured on the dorsum of the hand using a eutectic mixture of local anesthetics (EMLA) in parental presence in the preoperative area. Midazolam 0.5 mg i.v. was given and the child was transferred to the operating theatre where routine monitoring was attached. A flexometallic TT was kept at hand to replace the MT after induction of anaesthesia. To pre-oxygenate, oxygen tubing from the auxiliary oxygen source from anaesthesia machine was connected to the external limb of the MT. As the child resisted the connection (which was assumed due to anxiety), small aliquots of propofol were given to sedate the child. During the process, oxygen-connecting tubing from the MT ‘popped off’ seeming like a high pressure build up leading to disconnection. The child started to desaturate rapidly, so mask ventilation on occlusion of the anterior limb of MT was tried. However, no ventilation/chest rise could be achieved. The pulse oximeter saturation continued to decrease till 20% and heart rate began to decrease. The skin over the anterior limb was scarred and fibrosed removing the MT and inserting a tracheostomy/flexometallic TT required surgical incision on the scar tissue. The surgeon was asked to rapidly assist in emergency removal of the MT by incising the scar tissue. Meanwhile, considering the circumstantial possibility of block of the upper end of the MT, the anaesthesia circuit (circle system) was connected to the anterior limb of MT using an appropriate size TT connecter. This enabled us to ventilate the child without any leak from the upper end of the MT. The pulse oximeter saturation picked up (on 100% oxygen) and a visible chest rise could be appreciated (although the chest compliance seemed poor on bag ventilation). After ventilation for a few minutes, the haemodynamics became stable and ventilation was continued from the external limb without any detectable oral leak. An endoscopic assessment of the upper airway revealed mucosal overgrowth completely obstructing the top lumen of the MT (Fig. 1). The MT was removed and replaced with the flexometallic TT inserted through the orifice initially accommodating the external limb of the MT. An intraoperative fluoroscopic chest assessment to evaluate the possible cause of decreased compliance showed bilateral lung lower zone loculated pneumothorax. The airway was finally secured using a tracheostomy tube and on consultation with a chest physician, a computed tomography (CT)-guided chest tube/pigtail catheter insertion was planned subsequently. The present case illustrates that an apparently normal functioning MT after operation could lead to a potentially life-threatening hazard. The child had no predictors suggestive of difficult mask ventilation and had no respiratory obstruction after operation. The possibility of occlusion of the upper end of the MT could only be considered when bag-mask ventilation completely failed. Such a complication with an MT has not previously been reported. As a remedy to prevent such accidents, we suggest that during preoperative evaluation, the anterior limb of the MT should be occluded and ensured that the child continues to breathe normally without developing signs of respiratory distress/airway obstruction. In situations like the present case where tissue overgrows the upper end of the MT, occlusion of the anterior limb shall block the only patent airway path, thus presenting with signs of distress. Moreover, this will not only detect complete occlusion but can also predict a partial occlusion significant enough to cause intraoperative ventilatory difficulties. None declared.