Murphy Eye Research Articles

Unmasking hidden dangers: A manufacturing defect in Murphy's eye of an endotracheal tube.

Unmasking hidden dangers: A manufacturing defect in Murphy's eye of an endotracheal tube.

Behavior of Endotracheal Tube Cuff Pressure During a Routine Control Maneuver With Different Manometers.

The main functions of the endotracheal tube (ETT) cuff are to prevent aspiration and to allow pressurization of the respiratory system. For this purpose, it is essential to maintain adequate pressure inside the cuff, thus reducing the risks for the patient. It is regularly checked using a manometer and is considered the best alternative. The objective of this study was to evaluate the cuff pressure behavior of different ETTs during the simulation of an inflation maneuver using different manometers. A bench study was performed. Four brands of 8-mm internal diameter single lumen with a Murphy eye ETT with cuff and 3 different brands of manometers were used. In addition, a pulmonary mechanics monitor was connected to the inside of the cuff through the body of the distal end of the ETT. A total of 528 measurements were made on the 4 ETTs. During the complete procedure (connection and disconnection), there was a significant pressure drop of 7 ± 1.4 cm H2O from the initial pressure (Pinitial) (P < .001), of which 6 ± 1.4 cm H2O was lost during connection (difference between Pinitial and Pconnection). The Preconnection value was 19.1 ± 1.6 cm H2O, showing a significant total pressure drop of 11 ± 1.6 cm H2O (difference between Pinitial and Preconnection) (P < .001). The Pfinal mean was 29.6 ± 1.3 cm H2O. Significant differences were found between manometers according to the time of measurement. A similar phenomenon was evidenced when analyzing different ETTs. Significant pressure changes occur secondary to ETT cuff measurement, which has important implications for patient safety.

E&amp;P Notes (December 2022)

E&amp;P Notes (December 2022)

Pediatric Microcuff Tube for Neurosurgical Procedures: A Boon or Bane?

AbstractPediatric Microcuff endotracheal tubes have come into vogue in the last few years. It overcomes the problems faced with the uncuffed or conventional cuffed tubes used in the pediatric population. In addition, the more distal placement of the polyurethane cuffs in these tubes eliminates the risk of airway mucosal injury and hence postoperative stridor. This makes it an attractive option for neurosurgical patients where there is a high incidence of cranial nerve deficit, airway edema, and the requirement of prolonged postoperative ventilation. But due to this particular design, Murphy's eye is not incorporated in the tube, which can potentially hamper ventilation, especially when used for long duration surgery. With the help of our case report, we would like to warn the readers regarding this life-threatening complication that resulted in hypoxia in a 1-year-old child in the postoperative period.

Adverse event using Medtronic NIM™ EMG endotracheal tube on a patient receiving anesthesia for hemithyroidectomy: a case report

BackgroundThe neural integrity monitor (NIM) electromyogram (EMG) endotracheal (ET) tube is a widely used device to monitor neural response through muscle activity. It is helpful in surgical procedures with high risk of damaging delicate structures in the head and neck. This case provides a thorough analysis of an adverse event that was encountered in the operating room, which others can hopefully learn from.Case presentationWe are reporting a case in which a patient undergoing hemithyroidectomy had experienced an adverse event using the Medtronic NIM™ EMG endotracheal tube. After successful induction and intubation, confirming the proper positioning of the electrode wires was necessary before the incision could be made. Upon reexamination, the patient suddenly became difficult to ventilate with increased peak airway pressure, decreased tidal volume, and end tidal CO2. This episode lasted approximately 15 min and the patient’s condition remained stable despite low tidal volumes. The problem was unexpectedly resolved upon deflation of the cuff of the ET tube.ConclusionsThere are several similar reports of these endotracheal tubes causing obstruction, especially those in which overinflation of the cuff caused cuff herniation and blockage of the Murphy eye and the bevel. It is currently believed that the design of this tube allowed for the obstruction to occur. The patient’s short body habitus may have also been a small contributing factor. The distance that the electrodes must sit within the vocal cords to the tip of the bevel is longer in this type of ET tube compared with a standard ET tube. The distance from the true vocal cords to where the cuff sits in the trachea is also greater in this model NIM EMG tube. There was no confirmation of the exact obstructive process that took place, however, confirming the tube and cuff positioning would have been optimal.

Retrograde nasal intubation for an anticipated difficult intubation

A 58-year-old female patient with recurrence of carcinoma in the angle of the mouth on the left side was posted for composite resection and Pectoralis major myocutaneous flap reconstruction. The patient had carcinoma left buccal mucosa 1 year back and had undergone left partial mandiblectomy and radiotherapy. On airway examination (MPG) could not be assessed; on mouth opening one-and-half finger was admitted.There was a 4 cm × 4 cm ulceroproliferative growth in the left angle of the mouth extending to lower lip, which was bleeding on touch. After shifting to the operating theatre, venous access was secured with a with a wide-bore cannula. Standard monitoring was connected and preoxygenation was done. Under strict aseptic precaution under local anaesthesia, trachea located with Touhy's needle. Epidural catheter passed through the needle into the larynx and taken out through the oral cavity and Ryle's tube, which the patient already had for feeds, was pulled and taken out of the oral cavity. Catheter tip was tied to it and pulled out through the nostril and passed through murphy's eye of 6.5 mm (ID ETT) and lower end pulled, thereby pulling ETT into the trachea, cuff was inflated and tube fixed at 25 cm. General anaesthesia was administered. Thorough airway assessment, preparat ion and counselling of patient help in reducing airway-related morbidity and mortality.

Simulated dimensional compatibility of uncuffed and cuffed tracheal tubes for selective endobronchial intubation in children.

Cuffed tracheal tubes have recently been recommended for selective endobronchial intubation to establish single-lung ventilation even in smaller children. This implies that, compared with uncuffed tracheal tubes, the cuffed tracheal tubes selected will be smaller and therefore have a shorter length. We hypothesized that cuffed tracheal tubes might be of insufficient length for selective endobronchial intubation if the tube cuff were fully immersed in the left or right mainstem bronchus. The distance from the proximal end of the tracheal tube to the upper border of the cuff in cuffed tracheal tubes and to the upper margin of the Murphy eye in uncuffed tracheal tubes, respectively, was assessed in sizes 3.0-7.0mm internal diameter. The raw data sets of two previously performed studies obtained from 337 children aged from birth to 16years, including the distances "teeth to tracheal tube tip" and "tracheal tube tip to carina," were used to calculate age-, weight-, and height-related data for the distance from "teeth to carina." Tracheal tube dimensions were compared with age-related distances from "teeth to carina," applying published recommendations for the selection of uncuffed and cuffed tracheal tubes for selective endobronchial intubation in children. The differences between the length of the age-related tracheal tube and the tracheal tube insertion length required to guarantee full insertion of the tracheal tube cuff or the Murphy eye within the mainstem bronchus ranged from -3.5 to 52.6mm in cuffed tracheal tubes and from 42.3 to 83.3mm in uncuffed tracheal tubes. For many age groups of patients requiring selective endobronchial intubation, the lengths of cuffed tracheal tubes, in contrast to those of uncuffed tracheal tubes, were revealed to be critically short for safe taping outside the oral cavity with the cuff placed completely within the right or left mainstem bronchus.

Entrapment of an EZ-Blocker in the Murphy Eye of an Endotracheal Tube

Entrapment of an EZ-Blocker in the Murphy Eye of an Endotracheal Tube

Intubação seletiva do brônquio principal esquerdo em unidade de terapia intensiva neonatal

Selective neonatal left mainstem bronchial intubation to treat right lung disease is typically achieved with elaborate maneuvers, instrumentation and devices. This is often attributed to bronchial geometry which favors right mainstem entry of an endotracheal tube deliberately advanced beyond the carina.A neonate with severe bullous emphysema affecting the right lung required urgent non-ventilation of that lung. We achieved left mainstem bronchial intubation by turning the endotracheal tube 180° such that the Murphy's eye faced the left instead of the right, and simulated a left-handed intubation by slightly orientating the endotracheal tube such that its concavity faced the left instead of the right as in a conventional right-handed intubation.Urgent intubation of the left mainstem bronchus with an endotracheal tube can be easily achieved by recognizing that it is the position of the endotracheal tube tip and the direction of its concavity that are the chief determinants of which bronchus an endotracheal tube goes when advanced. This is important in critically ill neonates as the margin of safety and time window are small, and the absence of double-lumen tubes. Use of fiberoptic bronchoscope and blockers should be reserved as backup plans.

Inadvertent passage of a tracheostomy tube through Murphy's eye during percutaneous tracheostomy tube insertion

SummaryPercutaneous tracheostomies are commonly performed at the bedside in Critical Care Units. The use of bronchoscopy during the procedure is variable. We describe a case of inadvertent cannulation of Murphy's eye with a tracheostomy which initially went unrecognised. Recommendations from the NCEPOD report “On the right Trach” related to the use of bronchoscopy during percutaneous tracheostomy insertion and awareness of the nuances of different endotracheal tubes may have prevented this complication.

Keep an eye on Murphy's eye during percutaneous dilatational tracheostomy.

Sir, The report by Panigrahi etal. made for interesting reading.[1] We would like to make certain observations regarding such a complication. The polyvinyl chloride tracheal tube(TT) possesses a preformed contour. When we keep the tube in such a position that the inherent curve of the tube faces anteriorly, the attachment of the pilot balloon also faces anteriorly. In this position, beveled distal end of the tube faces to the left and the Murphy's eye to the right. When a right-handed anesthesiologist intubates the trachea with this tube, he performs laryngoscopy along the right border of the tongue and fixes the TT at the right corner of the mouth. In general, the TT curve is tilted toward right and the Murphy's eye faces posteriorly in this situation. Before performing percutaneous dilatational tracheostomy, the TT is withdrawn so that it does not come in the way of the introducer needle. If the TT is withdrawn in the same position as described above, it is extremely unlikely that the guidewire will enter the Murphy's eye without piercing the TT first. If the tube is rotated by 90° to the left by bringing its inherent curve anteriorly, there is again very little space for the guidewire to enter the Murphy's eye. Only if the TT is further rotated 90° to the left, the Murphy's eye is exposed to guidewire entry. This position of the TT is not the usual position in which the withdrawn tube is kept by most of the clinicians. Moreover, if the TT has been initially placed and subsequently withdrawn in such a position that its curve and pilot balloon attachment faced to the left, the Murphy's eye becomes directly exposed to guidewire entry leading to the problems described. Hence, we should be careful during the withdrawal of TT that it should not lie in a position that exposes the Murphy's eye to the path of the introducer needle. Another way in which the guidewire can enter the Murphy's eye is retrogradely. If the J-tip of the guidewire faces cephalad during insertion, it may move cephalad and enter the Murphy's eye. On looking closely at the two figures, we can conclude that in the second case, the guidewire had directly entered the Murphy's eye and not retrogradely. We are also concerned that during withdrawal of the TT, the guidewire was allowed to come out along with the tube. Loss of a correctly placed guidewire can be catastrophic in certain situations and attempts should be made to retain it in position. Finally, the introducer needle has no scope to “pierce” the Murphy's eye. All it can do is to “pass” through it! Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Procedural improvisation to prevent guidewire kinking in Griggs percutaneous tracheostomy without bronchoscopic guidance.

Sir, We read with great interest the case report titled, “Inadvertent migration of guidewire into Murphy's eye of endotracheal tube during percutaneous dilatational tracheostomy” by Binita et al.[1] We wish to highlight procedural modification we are doing in our Intensive Care Unit to tackle such inadvertent complication. We agree with the authors that migration of guidewire into the Murphy's eye of endotracheal tube during percutaneous tracheostomy without bronchoscopic guidance is a rare complication, which we also encounter rarely but we follow a procedural improvisation by ensuring free movement of guidewire back and forth at each step, thus ensuring proper placement of guidewire. In case of guidewire inside the Murphy's eye, there will be kinking of guidewire after dilatation with metal/plastic dilator, thus the free back and forth movement of the guidewire will not be appreciated, or in other words, if the free movement of guidewire not felt, a possible diagnosis of guidewire kinking is made. In our case series of 300 cases of percutaneous tracheostomy without bronchoscopic guidance, we had 18 cases where guidewire got kinked, hampering the free back and forth movement during the procedure.[2] We removed the guidewire and again a fresh puncture of trachea done to complete the procedure. Few possible reasons for guidewire kinking are such as cephalic migration or migration into the Murphy's eye or false passage can be easily diagnosed and rectified by ensuring the free back and forth movement of guidewire during each step of the procedure. In our case series, we have highlighted two important steps:First one by withdrawing of the endotracheal tube with inflated cuff while monitoring expired tidal volume on ventilator and the second one by ensuring free mobility of guidewire during each step of the procedure, thereby ensuring a safe placement of the tracheostomy tube in trachea. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Airway management in patient with continuous bleeding lesion of the trachea: a case report

Hemoptysis requires proper treatment to prevent blood aspiration and asphyxiation. If the patient loses consciousness or is anesthetized, the bleeding inside the trachea may continuously flow into the distal part, which may be fatal. Fatal damage resulting from hemoptysis is mainly caused by asphyxiation, and it is important to find the exact location of the bleeding in order to prevent it from spreading to both lungs. However, endotracheal intubation may increase the bleeding by stimulating the bleeding lesion in the respiratory track, and can make airway management more difficult. We report a successful case of airway management using the cuff and Murphy eye of the endotracheal tube in a patient with tracheal bleeding.

Evaluation of intubating conditions using stylet by conventional through-tube technique and through Murphy's eye in patients with high Mallampati scores.

Background:Difficult intubation is always a nightmare for an Anaesthetist. This study was planned to study the alternative method of stylet use during difficult oro-tracheal intubation. Outcome measures assessed were ease of intubation, hemodynamic stability and reducing complications.Materials and Methods:A cohort of 60 patients of Mallampati class III patients was formed and patients were divided into two groups. In group 1 patients, conventional through tube method was used for inserting stylet, whereas, in group 2 patients, Murphy's eye was used for inserting malleable flexi tip stylet.Results:Hemodynamic stability in terms of mean arterial blood pressure and heart rate was observed in group 2. Intubating time, number of attempts of successful intubation and post operative pharyngo-laryngeal complications was also low in group 2 patients.Conclusion:The use of Murphy's eye to pass stylet during difficult airway manoeuvre is a safe alternative over conventional rail-road technique.

Pneumoperitoneum in a patient with Larsen syndrome

To the Editor: Larsen syndrome is a congenital disorder, which consists of a skeletal dysplasia with multiple joint dislocations and a characteristic face [1]. The basis of the abnormalities is considered to be a generalized mesenchymal disorder involving connective tissues [2]. We describe a patient with Larsen syndrome who suffered from pneumoperitoneum during mechanical ventilation. A 16-year-old boy with Larsen syndrome was admitted because of respiratory failure. Immediately after admission, his airway was established using a cuffed 6.0-mm tracheal tube without a Murphy eye. His chest X-ray showed severe scoliosis and implied a possibility of endobronchial shift or carinal impingement of the tracheal tube. His deformity allowed only a margin of 1.0–0.5 cm between the tube end and the carina. Expiratory tidal volumes depended on patient positioning because of severe scoliosis. On the next day, his abdomen became tense and distended. A chest-abdominal X-ray revealed free air under the diaphragm and subcutaneous emphysema. In addition, carinal impingement of the tracheal tube was confirmed (Supplementary Fig. 1). A chest-abdominal CT showed free peritoneal air and emphysema in the anterior abdominal wall (Supplementary Fig. 2). Pneumomediastinum and massive subcutaneous emphysema were confirmed (Supplementary Fig. 3). We attempted to correct the position of the tracheal tube, which impinged on the carina. With careful management regarding the tube position, his respiratory status finally improved. The air leak was probably derived from a micro-tear of the trachea, because carinal impingement of the tracheal tube was repeatedly observed. The background status, which in this case means weakness of connective tissues due to Larsen syndrome, seemed to predispose to the air leak. Air may leak into the mediastinum and then into the retroperitoneal space and the peritoneum by the diaphragmatic openings [3]. After correction of the tube position, positive pressure was effectively delivered to alveoli instead of directly to the tracheal wall, which appeared to decrease the air leak and free peritoneal air.

Efficiency, Efficacy, and Safety of EZ-Blocker Compared with Left-sided Double-lumen Tube for One-lung Ventilation

Double-lumen tubes (DLTs) or bronchial blockers are commonly used for one-lung ventilation. DLTs are sometimes difficult or even impossible to introduce, and the incidence of postoperative hoarseness and airway injuries is higher. Bronchial blockers are more difficult to position and need more frequent intraoperative repositioning. The design of a Y-shaped bronchial blocker, the EZ-Blocker (Teleflex Life Sciences Ltd., Athlone, Ireland) (EZB), combines some advantages of both techniques. The objective of this study was to assess whether EZB performs clinically better than left-sided DLTs (Broncho-cath; Mallinckrodt, Athlone, Ireland) without causing more injury. Primary outcome was the frequency of initial malpositions. Eligible patients were adults scheduled for surgery requiring one-lung ventilation who met criteria for placement of both devices. In this parallel trial, 100 consecutive and blinded patients were assigned randomly using a computer-generated list to two groups. The incidence of malposition and ease and time of placement were recorded. Blinded assessors investigated quality of lung deflation, postoperative complaints, and damage to the airway. Placement of a DLT was unsuccessful twice. The incidence of initial malposition was high and comparable between EZBs (37 of 50) and DLTs (42 of 49) (P = 0.212). Placing single-lumen tubes and EZBs took more time but was rated easier. Quality of lung deflation was comparable. Fewer patients in the EZB group complained of sore throat at day 1. There was a higher incidence of tracheal hematoma and redness and bronchial hematoma in the DLT group. The EZB is an efficient and effective device for one-lung ventilation and causes less injury and sore throat than a DLT.

Unrecognized bronchial intubation associated with the uncuffed pediatric tracheal tube with bilateral Murphy eyes

Unreliability of breath sounds auscultation after intubation is reportedly mainly related to the presence of the Murphy eye. This study was performed to ascertain whether an uncuffed pediatric tracheal tube with bilateral Murphy eyes increases the risk of unrecognized bronchial intubation, compared to an uncuffed tube without eyes. Following induction of anesthesia in 50 toddlers, either an uncuffed tube without eyes or an uncuffed tube with bilateral eyes was inserted into the trachea. The tube was then slowly advanced while breath sounds were auscultated using a stethoscope. In study 1, when breath sounds changed and disappeared, the distance from the carina to the tube tip was measured using a fiberoptic bronchoscope. In study 2, when breath sounds changed, the tracheal tube was withdrawn 5, 10, 15 and 20 mm while using a fiberoptic bronchoscope to ascertain whether bronchial intubation had occurred. When breath sounds changed and disappeared, the tip of the tube with bilateral eyes was positioned more deeply below the carina than that of the tube without eyes. When the tube was withdrawn 10 mm from the point at which breath sounds changed, frequencies of bronchial intubation were 13% and 80% in the no eyes and double eyes groups, respectively. An uncuffed pediatric tracheal tube with bilateral Murphy eyes reduces the ability of breath sounds auscultation to detect bronchial intubation and may increase the risk of unrecognized bronchial intubation compared to an uncuffed tube without eyes.

Endotracheal tube fire during tracheostomy

Endotracheal tube fire during tracheostomy

Provision of stable lung isolation in an unstable patient: an endobronchial blocker through the Murphy eye of the in situ endotracheal tube

Shortly after repair of a type A aortic dissection, resternotomy was required because of tamponade. During the exploration, it was discovered that the source of bleeding was in the right pleura. Collapse of the right lung was requested. A double-lumen tube would have necessitated changing the endotracheal tube (ETT) in an unstable patient in the middle of surgery. Instead, a Coopdech endobronchial blocker was passed into the right lung through the lumen of the in situ ETT. To ensure that the blocker did not migrate into the trachea, it was deliberately passed through the Murphy eye of the ETT, which had been deliberately passed distally to almost touch the carina. This arrangement provided reliable right-lung collapse to facilitate right pleural hemostasis.

Frank J. Murphy, M.D., C.M., 1900–1972

Frank J. Murphy, M.D., C.M., 1900–1972