An initial experience with an Extraluminal EZ-Blocker® : A new alternative for 1-lung ventilation in pediatric patients

Hypoxemia in School-age Children Undergoing One-lung Ventilation: A Retrospective Cohort Study from the Multicenter Perioperative Outcomes Group

BACKGROUND

Risk factors for hypoxemia in school-age children undergoing one-lung ventilation remain poorly understood. The hypothesis was that certain modifiable and nonmodifiable factors may be associated with increased risk of hypoxemia in school-age children undergoing one-lung ventilation and thoracic surgery.

METHODS

The Multicenter Perioperative Outcomes Group database was queried for children 4 to 17 yr of age undergoing one-lung ventilation. Patients undergoing vascular or cardiac procedures were excluded. The original cohort was divided into two cohorts: 4 to 9 and 10 to 17 yr of age inclusive. All records were reviewed electronically for the primary outcome of hypoxemia during one-lung ventilation, which was defined as an oxygen saturation measured by pulse oximetry (Spo2) less than 90% for 3 min or longer continuously, while severe hypoxemia was defined as Spo2 less than 90% for 5 min or longer. Potential modifiable and nonmodifiable risk factors associated with these outcomes were evaluated using separate multivariable least absolute shrinkage and selection operator regression analyses for each cohort. The covariates evaluated included age, extremes of weight, American Society of Anesthesiologists Physical Status of III or higher, duration of one-lung ventilation, preoperative Spo2 less than 98%, approach to one-lung ventilation, right operative side, video-assisted thoracoscopic surgery, lower tidal volume ventilation (defined as tidal volume of 6 ml/kg or less and positive end-expiratory pressure of 4 cm H2O or greater for more than 80% of the duration of one-lung ventilation), and procedure type.

RESULTS

The prevalence of hypoxemia in the 4- to 9-yr-old cohort and the 10- to 17-yr-old cohort was 24 of 228 (10.5% [95% CI, 6.5 to 14.5%]) and 76 of 1,012 (7.5% [95% CI, 5.9 to 9.1%]), respectively. The prevalence of severe hypoxemia in both cohorts was 14 of 228 (6.1% [95% CI, 3.0 to 9.3%]) and 47 of 1,012 (4.6% [95% CI, 3.3 to 5.8%]). Initial Spo2 less than 98% was associated with hypoxemia in the 4- to 9-yr-old cohort (odds ratio, 4.20 [95% CI, 1.61 to 6.29]). Initial Spo2 less than 98% (odds ratio, 2.76 [95% CI, 1.69 to 4.48]), extremes of weight (odds ratio, 2.18 [95% CI, 1.29 to 3.61]), and right-sided cases (odds ratio, 2.33 [95% CI, 1.41 to 3.92]) were associated with an increased risk of hypoxemia in the older cohort. Increasing age (1-yr increment; odds ratio, 0.88 [95% CI, 0.80 to 0.97]) was associated with a decreased risk of hypoxemia.

CONCLUSIONS

An initial room air oxygen saturation of less than 98% was associated with an increased risk of hypoxemia in all children 4 to 17 yr of age. Extremes of weight, right-sided cases, and decreasing age were associated with an increased risk of hypoxemia in children 10 to 17 yr of age.

EDITOR’S PERSPECTIVE

Preoperative preparation and postoperative care in children in thoracic surgery

Anesthesia for pediatric patients undergoing thoracic surgery continues to be distinctive due to differing anatomical and physiological characteristics compared to adults. Adequate preoperative preparation, appropriate tool selection for providing one-lung ventilation, perioperative pain management, and a multidisciplinary approach can ensure higher quality postoperative care. In this review, the perioperative anesthesia management for pediatric patients undergoing thoracic surgery will be discussed, starting from the preoperative preparation phase. Additionally, the issues related to the application and management of one-lung ventilation will also be assessed.

A Practical Guide for Using the EZ-Blocker Endobronchial Blocker: Tips and Tricks After 10 Years of Experience

The EZ-Blocker (EZB) is a "Y-shaped," semirigid endobronchial blocker used for lung isolation and one-lung ventilation during thoracic surgery. Like many medical tools, initial efforts to use this endobronchial blocker may prove challenging for the uninitiated. However, some tips and tricks can be applied fairly rapidly to aid the clinician in properly placing the device, and, furthermore, may help the clinician get the most out of this innovative device. This article focuses on some of the technical aspects of its placement that the authors have developed over time. Additionally, other facets and potential pitfalls are discussed that relate to intraprocedural issues that may sometimes arise when using this device. The following aspects of the EZB as a lung-isolation device are discussed: standard positioning techniques, alternative positioning techniques, use in pediatric patients, approaches to achieving exceptional lung isolation, advanced uses, and limitations and potential issues. Although some information was taken from the authors' rather extensive experience with using this endobronchial blocker, some of the relevant literature are also reviewed, with the goal of being to improve the reader's knowledge of the device and improve the likelihood of its successful placement. The underlying design of the EZB remains unique among commercially available bronchial blockers in improving positional stability. The Y-shaped conformation, however, can lead to challenges when positioning the device in some patients. Therefore, some very practical tips and tricks are provided to assist the clinician in correctly positioning the device and other hints to improve the quality of lung isolation and surgical conditions.

Comparison of left double lumen tube and y-shaped and double-ended bronchial blocker for one lung ventilation in thoracic surgery—a randomised controlled clinical trial

Background

Double lumen tube (DLT) intubation is the most commonly used technique for one lung ventilation. Bronchial blockers (BB) are an alternative, especially for difficult airways. The EZ-bronchial blocker (EZB) is an innovative y-shaped and double-ended device of the BB family.

Methods

A randomised, controlled trial was conducted in 80 patients undergoing elective thoracic surgery using DLT or EZB for one lung ventilation (German Clinical Trial Register DRKS00014816). The objective of the study was to compare the clinical performance of EZB with DLT. Primary endpoint was total time to obtain successful one lung ventilation. Secondary endpoints were time subsections, quality of lung collapse, difficulty of intubation, any complications during the procedure, incidence of objective trauma of the oropharynx and supraglottic space and intubation-related subjective symptoms.

Results

74 patients were included, DLT group (n = 38), EZB group (n = 36). Median total time to obtain one lung ventilation [IQR] in the DLT group was 234 s [207 to 294] versus 298 s [243 to 369] in the EZB group (P = 0.007). Median total time was relevantly influenced by different preparation times. Quality of lung collapse was equal in both groups, DLT group 89.5% were excellent vs. 83.3% in the EZB group (P = 0.444). Inadequate lung collapse in five patients of the EZB group resulted in unsuccessful repositioning attempts and secondary DLT placement. Endoscopic examinations revealed significantly more carina trauma (P = 0.047) and subglottic haemorrhage (P = 0.047) in the DLT group. Postoperative subjective symptoms (sore throat, hoarseness) were more common in the DLT group, as were speech problems.

Conclusions

Using EZB prima facie results in prolonged time to obtain one lung ventilation with equal quality of lung collapse for the thoracic surgeon. If preparation times are omitted in the analysis, the time difference is statistically and clinically not relevant. Our data showed only little evidence for reducing objective airway trauma as well as subjective complaints. In summary both procedures were comparable in terms of times and clinical applicability. Therefore decisions for DLT or EZB should depend more on individual experience, in-house equipment and the individual patient, than on any times that are neither clinically significant nor relevant.

Trial registration

German Clinical Trial Register DRKS00014816, prospectively registered on 07.06.2018

Challenge of Lung Isolation in Patients with Vocal Cord Implants

Glottic closure insufficiency increases the risk of aspiration and pneumonia, particularly in the elderly. Medialization thyroplasty is an open surgical procedure for treating glottic incompetency by approximating both vocal folds. The vocal fold medialization is achieved by inserting an implant to bring the nonmobile fold to the unaffected side. Lung isolation in patients with vocal cord implantation poses a unique challenge. Understanding the risks of different modalities of lung isolation and their impacts on the vocal cord implant is crucial to implementing a specifically tailored plan. Preoperative bronchoscopy, intraoperative video laryngoscopy, and bronchoscopy are ideal methods for assessing the vocal fold implants and guiding the lung isolation technique. Bronchial blocker through a single-lumen endotracheal tube may be the preferred choice to avoid the injury of the stretched vocal cords and dislodgement of the implant by a larger diameter double-lumen tube.

Use of Fogarty catheter as bronchial blocker for lung isolation in children undergoing thoracic surgery: A single centre experience of 15 cases

Background and Aim:

Various devices such as single lumen tubes, balloon-tipped bronchial blockers, and double-lumen tubes can be used for lung isolation in children, but no particular device is ideal. As such, there is a wide variation in lung isolation techniques employed by anaesthesiologists in this cohort of patients. This study aims to describe our experience with Fogarty catheters for lung isolation in children.

Methods:

This was a single centre, retrospective review of 15 children, below the age of 8 years, undergoing thoracic surgeries and requiring lung isolation. Demographic details, clinical parameters, complications during Fogarty catheter placement, number of attempts for placement, time taken for satisfactory lung isolation, and intraoperative complications were collected.

Results:

Successful lung isolation was achieved in all 15 children with Fogarty catheters of various sizes with the help of flexible bronchoscopy. Desaturation and bradycardia were the commonest complications seen during placement of the catheters but resolved with bag-mask ventilation. On average, 2 attempts were required for successful Fogarty placement. The mean time for successful lung isolation was 6.9 ± 1.3 minutes. The commonest intraoperative complication noted was desaturation, which resolved with an increase in FiO₂and positive end expiratory pressure. 2 children had migration of the device proximally to the trachea causing airway obstruction. The devices were successfully repositioned in both cases.

Conclusion:

Fogarty catheters can be used for successful lung isolation in children less than 8 years of age, undergoing thoracic surgery.

Anesthesia for thoracic surgery in infants and children

The management of infants and children presenting for thoracic surgery poses a variety of challenges for anesthesiologists. A thorough understanding of the implications of developmental changes in cardiopulmonary anatomy and physiology, associated comorbid conditions, and the proposed surgical intervention is essential in order to provide safe and effective clinical care. This narrative review discusses the perioperative anesthetic management of pediatric patients undergoing noncardiac thoracic surgery, beginning with the preoperative assessment. The considerations for the implementation and management of one-lung ventilation (OLV) will be reviewed, and as will the anesthetic implications of different surgical procedures including bronchoscopy, mediastinoscopy, thoracotomy, and thoracoscopy. We will also discuss pediatric-specific disease processes presenting in neonates, infants, and children, with an emphasis on those with unique impact on anesthetic management.

Effects of bronchial blockers on gas exchange in infants with one-lung ventilation: a single-institutional experience of 22 cases

BACKGROUND

One-lung ventilation (OLV) in infants is a commonly used airway technique during thoracic surgery. Current research has primarily focused on the operation of the airways and the occurrence of complications. However, there has been minimal data on the pulmonary gas exchange in infants before and after OLV. This study aimed to assess the efficacy of bronchial blockers (BBs) on the pulmonary gas exchange in infants with OLV.

METHODS

A total of 22 infants requiring OLV from January 2017 to August 2019 were included in this study. OLV was achieved by placing BBs outside the endotracheal tube, and all surgeries were performed by the same experienced anesthesiologist. Numerous clinical features, including the oxygenation index (OI), alveolar-arterial oxygen tension gradient (P_A-aO₂), pulmonary dynamic compliance (Cdyn), OLV time, pulmonary collapse time, degree of pulmonary collapse at the operative side, operative time, and immediate hemodynamic indexes before and after intubation were assessed. Data from the arterial blood gases and the ventilator's parameters were obtained at three time points: 15 minutes before OLV (pre-OLV), 15 minutes after the initiation of OLV (during OLV), and 15 minutes after the termination of OLV (post-OLV).

RESULTS

For all patients, the pulmonary gas exchange during OLV was significantly different from both pre-OLV and post-OLV. However, no significant changes of pulmonary function were observed before and after OLV. Extended OLV time was associated with decreased OI and Cdyn, and increased P_A-aO₂ gradient (P<0.001). In addition, no significant changes of hemodynamic indexes before and after intubation were detected. The degree of lung collapse on the operational side during OLV was optimal.

CONCLUSIONS

In this study, the efficacy of BBs on the pulmonary gas exchange in infants with OLV was assessed. The results suggested that although each parameter of pulmonary function pre-OLV were similar to those of post-OLV, an extended period of OLV may lead to compromised lung function.

A Randomized Comparison of Positional Stability: The EZ-Blocker Versus Left-Sided Double-Lumen Endobronchial Tubes in Adult Patients Undergoing Thoracic Surgery

OBJECTIVE

To assess if there is a difference in the repositioning rate of the EZ-Blocker versus a left-sided double-lumen endobronchial tube (DLT) in patients undergoing thoracic surgery and one-lung ventilation.

DESIGN

Prospective, randomized.

SETTING

Single center, university hospital.

PARTICIPANTS

One hundred sixty-three thoracic surgery patients.

INTERVENTIONS

Patients were randomized to either EZ-Blocker or a DLT.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was positional stability of either the EZ-Blocker or a left-sided double-lumen endobronchial tube, defined as the number of repositionings per hour of surgery and one-lung ventilation. Secondary outcomes included an ordinal isolation score from 1 to 3, in which 1 was poor, up to 3, which represented excellent isolation, and a visual analog postoperative sore throat score (0-100) on postoperative days (POD) one and two. Rate of repositionings per hour during one-lung ventilation and surgical manipulation in left-sided cases was similar between the two devices: 0.08 ± 0.15 v 0.11 ± 0.3 (p = 0.72). In right-sided cases, the rate of repositioning was higher in the EZ-Blocker group compared with DLT: 0.38 ± 0.65 v 0.09 ± 0.21 (p = 0.03). Overall, mean isolation scores for the EZ-Blocker versus the DLT were 2.76 v 2.92 (p = 0.04) in left-sided cases and 2.70 v 2.83 (p = 0.22) in right-sided cases. Median sore throat scores for left sided cases were 0 v 5 (p = 0.13) POD one and 0 v 5 (p = 0.006) POD two for the EZ-Blocker and left-sided DLT, respectively.

CONCLUSION

For right-sided procedures, the positional stability of the EZ-Blocker is inferior to a DLT. In left-sided cases, the rate of repositioning for the EZ-Blocker and DLT are not statistically different.

Selective bronchial intubation for one-lung ventilation and independent-lung ventilation in pediatric age: state of the art

Selective bronchial intubation (SBI) to ventilate a single lung (one-lung ventilation, OLV) or to apply separate lung ventilation (independent-lung ventilation, ILV) can be frequently required under general anesthesia in pediatrics, mainly in video assisted thoracoscopy surgery, in the postoperative care of cardio-thoracic surgery, and for the treatment of lung pathologies with unilateral prevalence in intensive care. In children over 6-8 years of age SBI, OLV and ILV can be performed using marketed double-lumen tubes (DLTs). In neonates, infants and younger children the application of ILV is limited due to the lack of DLTs. For children of this age, a specific DLT for ILV was developed (Marraro Paediatric Endobronchial Bilumen Tube®) but is currently available only as a special product. The DLT represents the device of choice for OLV and ILV while the use of bronchial blocker is suggested as an alternative to achieve the SBI and the OLV when suitable DLTs are not available. Different catheters types can be used as bronchial blocker. If SBI is not possible using DLT or bronchial blocker, a conventional single-lumen tube of adequate length can allow SBI in all pediatric ages. Using the bronchial blocker and single lumen tube it is possible to perform OLV but it is impossible to apply ILV. The main complications of SBI and DLT are largely due to limited operator experience. Airway trauma, dislodgment and obstruction of the devices are quite frequent and can lead to severe hypoxia if not recognized and treated early.

Successful use of an EZ-blocker for lung isolation and management in a hemoptysis patient

When massive hemoptysis develops suddenly, patients typically die due to hypovolemia or airway obstruction. Intubation, endobronchial blocking, and elimination of blood clots are urgently required. However, existing double-lumen tubes and single endobronchial balloon systems are inadequate. We herein report successful EZ-blocker-mediated one-lung ventilation of a patient with a massive hemoptysis who required emergency life-saving surgery.

Selective pulmonary lobe isolation with Arndt pediatric endobronchial blocker for an infant: A case report

INTRODUCTION

Attaining lung isolation in the infant is a challenge for anesthesia care providers. Pulmonary lobe isolation is more challenging. We describe an approach to performing selective pulmonary lobe isolation using the pediatric endobronchial blocker in an infant in the absence of appropriate auxiliary guidance tool.

PATIENT CONCERNS

An 8-month-old and 9.5 kg male infant was admitted because of repeated cough with fever for 3 months and a large cyst of his right lung for 2 weeks. He had been living in a pastoral area with his parents.

DIAGNOSIS

Based on the chest computed tomography (CT) and his history about long-term residence in the pastoral area, this patient's diagnosis was considered as right middle lobe hydatid cyst.

INTERVENTIONS

Guided by a fiberoptic bronchoscope, a cuffed 4.0-mm inside diameter (ID) endotracheal tube was successfully placed into the right main bronchus of this infant. Then, pediatric 5-French (Fr) endobronchial blocker was placed into the right middle and lower lobes through the endotracheal tube without navigation of fiberoptic bronchoscope.

OUTCOMES

Lobe isolation was successfully achieved for right middle lobectomy. This approach allows clinicians to perform lobe isolation in the absence of fiberoptic bronchoscope with very small outer diameter.

CONCLUSION

This technique is relatively easy to use and less dependent on equipment with small outer diameter in the selective pulmonary lobe isolation in infants and small children.

The EZ-blocker for one-lung ventilation in patients undergoing thoracic surgery: clinical applications and experience in 100 cases in a routine clinical setting

Background

In certain clinical situations the insertion of a double-lumen tube (DLT) for one-lung ventilation (OLV) is not feasible or unfavorable. In these cases, the EZ-Blocker (EZB) may serve as an alternative. The aim of our analysis was to report on the clinical applications and our experience with the EZB for one-lung ventilation in 100 patients undergoing thoracic surgery.

Methods

All anesthetic records from patients older than 18 years of age undergoing general anesthesia in the department of thoracic surgery with intraoperative use of an EZB for OLV at the University Hospital of Erlangen in four consecutive years were analyzed retrospectively.

Results

Most frequently, EZB was used in difficult airway (27%) and for surgical procedures with high risk for left recurrent laryngeal nerve injury (21%), followed by application in intubated (12%) or tracheostomized (11%) patients. 11% of the patients had an increased risk of gastric regurgitation. Almost all EZBs were placed free of complications (99%). Clinically sufficient lung collapse was achieved in all patients. No serious airway injuries or immediate complications were documented.

Conclusions

The EZB is an efficient, easy-to-use and safe airway device and enables OLV in several clinical situations, when conventional DLTs are not feasible or less favorable. Three major applications were depicted from the data: expected difficult airway, surgical procedures with necessity of intraoperative recurrent laryngeal nerve monitoring and already intubated or tracheostomized patients.