A novel combined approach to placement of a double lumen endobronchial tube using a video laryngoscope and fiberoptic bronchoscope: a retrospective chart review.

BACKGROUND: The objective of this study was to evaluate a modern combined video laryngoscopy and flexible fiberoptic bronchoscope approach to placement of a double lumen endobronchial tube and further characterize potential strengths and weaknesses of this approach. METHODS: Retrospective chart review was conducted at our single institution, academic medical center, tertiary-care hospital. Patients aged 18 years of age or older were evaluated who underwent thoracic surgery and one-lung ventilation with placement of a double lumen endobronchial tube using a novel combined video laryngoscopy and flexible fiberoptic bronchoscope approach. No interventions were performed. RESULTS: Demographics and induction and intubation documentation were reviewed for 21 patients who underwent thoracic surgery and one-lung ventilation with placement of a double lumen endobronchial tube using a novel combined video laryngoscopy and flexible fiberoptic bronchoscope approach. First pass success using the combined approach was 86% (18/21). The five patients with an anticipated difficult airway had successful double lumen endobronchial tube placement on the first attempt. There were no instances of desaturation during double lumen endobronchial tube placement. No airway complications related to double lumen endobronchial tube placement were recorded. CONCLUSION: Use of a combined approach employing video laryngoscopy and a flexible fiberoptic bronchoscope may represent a reliable alternative approach to placement of double lumen endobronchial tubes.

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.

Alfentanil Pretreatment for Electroconvulsive Therapy-Associated Hemodynamic Lability: A Prospective Randomized Crossover Trial.

OBJECTIVES: Electroconvulsive therapy (ECT) is frequently associated with significant hemodynamic changes that increase myocardial oxygen demand including significant hypertension poststimulus. This raises concern about the cumulative effect of repetitive stress from ECT. Historically, various agents have been used to blunt this response and reduce hemodynamic fluctuations in these patients with varying degrees of efficacy. We hypothesized that bolus alfentanil administration timed with the ECT stimulus may reduce near-term hypertension and heart rate (HR) increases in patients undergoing ECT. METHODS: A randomized, double-blind, placebo-controlled AB/BA crossover trial of 87 patients 18 years or older with mood disorders was carried out. Patients received a standardized anesthetic regimen including induction with methohexital and succinylcholine and were randomized to receive either 20 µg/kg ideal bodyweight of alfentanil or placebo 60 seconds before the ECT stimulus for the first treatment and then crossed over to the other group for the second treatment. The primary outcome was the within-individual difference in preinduction systolic blood pressure and the first systolic blood pressure after the ECT stimulus. RESULTS: Eighty-seven patients completed the protocol. The primary outcome of increase in systolic blood pressure pre-ECT to post-ECT was 16.9 mm Hg less in the alfentanil group than the placebo group (95% confidence interval, -26.0 to -7.8; P < 0.001). The maximum HR was 6.5 beats per minute lower (95% confidence interval, -12.1 to -0.9; P = 0.024) when patients received alfentanil compared with placebo. CONCLUSIONS: Premedication with alfentanil reduces poststimulus hypertension and increased HR in patients receiving ECT and therefore, may reduce morbidity related to this in susceptible patients.

Near-Infrared Spectroscopy for Determination of Cardiac Output Augmentation in a Swine Model of Ischemia-Reperfusion Injury.

CONTEXT: Near infrared spectroscopy (NIRS) is a noninvasive tool for assessing local oxygen balance. In circulatory shock, the microcirculatory environment as measured by NIRS during resuscitation may provide additional diagnostic tools of value to the critical care physician. HYPOTHESIS: To assess whether a relative increase in peripheral NIRS was correlated with a clinically relevant increase in cardiac output following a fluid bolus in a swine model of shock. METHODS AND MODELS: Nine healthy young adult swine with median weight 80 kg (interquartile range, 75-83 kg) were anesthetized and surgically instrumented. They underwent a controlled hemorrhage of 20% of their blood volume followed by partial or complete aortic occlusion to create a variable ischemia-reperfusion injury. Next, the animals underwent four 500-mL plasmalyte boluses over 9 minutes each followed by a 6-minute pause. The animal then underwent a 25% mixed auto/homologous blood transfusion followed by four more 500 mL plasmalyte boluses over 9 minutes. Finally, the animals underwent a 25% mixed auto/homologous blood transfusion followed by an additional four rounds of 500-mL plasmalyte boluses over 9 minutes. Left thoracic limb NIRS, descending thoracic aortic flow (dAF), arterial blood pressure (MAP), central venous pressure (CVP), and mixed central venous oxygen saturation (Svo2) were measured continuously for comparison. RESULTS: The area under the receiver operating curve for an increase in dAF of 10% in response to a 500 mL bolus based on a percent increase in the proximal NIRS was 0.82 with 95% CI, 0.72-0.91; Svo2, 0.86 with 95% CI, 0.78-0.95; MAP, 0.75 with 95% CI, 0.65-0.85 and CVP, 0.64 with 95% CI, 0.53-0.76. INTERPRETATION AND CONCLUSIONS: A dynamic relative increase in NIRS in response to a crystalloid challenge has moderate discriminatory power for cardiac output augmentation during shock in a swine model of ischemia-reperfusion injury. NIRS performed as well as invasive measurements (Svo2 and MAP) and better than CVP.

Endobronchial Intubation to Facilitate Extraluminal Bronchial Blocker Placement in Young Children: A Retrospective Case Series.

OBJECTIVES: Extraluminal bronchial blocker placement has become a well-accepted approach to one-lung ventilation in young children. In some cases, technical issues with placement may require alternative approaches to correct bronchial blocker positioning. The primary aim of this study was to review the authors' experience with using endobronchial intubation to facilitate extraluminal bronchial blocker placement in young children. DESIGN: Single-center case series of pediatric patients undergoing thoracic surgery and one-lung ventilation using a bronchial blocker. SETTING: Tertiary academic medical center. PARTICIPANTS: Pediatric patients < three years of age undergoing thoracic surgery and one-lung ventilation who underwent bronchial blocker placement using endobronchial intubation to facilitate blocker placement. In all patients, the bronchial blocker was inserted through a selectively mainstemmed endotracheal tube to facilitate blocker positioning. INTERVENTIONS: No interventions were performed. MEASUREMENTS AND MAIN RESULTS: Fifteen patients were identified after a query of the local electronic health record. There were five right-sided and ten left-sided placements in this cohort. Bronchial blocker placement was successful in 14 of 15 patients using endobronchial intubation to facilitate bronchial blocker placement. In one patient, the bronchial blocker was discovered in the nonsurgical bronchus, following placement with this technique. The bronchial blocker was repositioned manually into the desired mainstem bronchus prior to lateral positioning. CONCLUSIONS: Mainstem intubation can be used to facilitate bronchial blocker placement in young children and represents an alternative approach to extraluminal bronchial blocker placement.

Risk assessment and optimization strategies to reduce perioperative respiratory adverse events in pediatric anesthesia-Part 1 patient and surgical factors.

Pediatric surgery cases are increasing worldwide. Within pediatric anesthesia, perioperative respiratory adverse events are the most common precipitant leading to serious complications. They can have intraoperative impact on the surgical procedure itself, lead to premature case termination and in addition may have postoperative impact resulting in longer hospitalization stays and costs. Although most perioperative respiratory adverse events can be promptly detected and managed, and will not lead to any sequelae, the risk of life-threatening progression remains. The incidence of respiratory adverse events increases in children with comorbid respiratory and/or nonrespiratory illnesses. Optimized perioperative patient care, risk-stratified care level choice, and practitioners with appropriate training allow for risk mitigation. This review will discuss patient and surgical risk factors with a focus on common patient comorbid illnesses and review scoring systems to quantify risk.

Hypoxemia in Young Children Undergoing One-lung Ventilation: A Retrospective Cohort Study.

BACKGROUND: One-lung ventilation in children remains a specialized practice with low case numbers even at tertiary centers, preventing an assessment of best practices. The authors hypothesized that certain case factors may be associated with a higher risk of intraprocedural hypoxemia in children undergoing thoracic surgery and one-lung ventilation. METHODS: The Multicenter Perioperative Outcomes database and a local quality improvement database were queried for documentation of one-lung ventilation in children 2 months to 3 yr of age inclusive between 2010 and 2020. Patients undergoing vascular or other cardiac procedures were excluded. All records were reviewed electronically for the presence of hypoxemia, oxygen saturation measured by pulse oximetry (Spo2) less than 90% for 3 min or more continuously, and severe hypoxemia, Spo2 less than 90% for 5 min or more continuously during one-lung ventilation. Records were also assessed for hypercarbia, end-tidal CO2 greater than 60 mmHg for 5 min or more or a Paco2 greater than 60 on arterial blood gas. Covariates assessed for association with these outcomes included age, weight, American Society of Anesthesiologists (Schaumburg, Illinois) Physical Status 3 or greater, duration of one-lung ventilation, preoperative Spo2 less than 98%, bronchial blocker versus endobronchial intubation, left operative side, video-assisted thoracoscopic surgery, lower tidal volume ventilation (tidal volume less than or equal to 6 ml/kg plus positive end expiratory pressure greater than or equal to 4 cm H2O for more than 80% of the duration of one-lung ventilation), and type of procedure. RESULTS: Three hundred six cases from 15 institutions were included for analysis. Hypoxemia and severe hypoxemia occurred in 81 of 306 (26%) patients and 56 of 306 (18%), respectively. Hypercarbia occurred in 153 of 306 (50%). Factors associated with lower risk of hypoxemia in multivariable analysis included left operative side (odds ratio, 0.45 [95% CI, 0.251 to 0.78]) and bronchial blocker use (odds ratio, 0.351 [95% CI, 0.177 to 0.67]). Additionally, use of a bronchial blocker was associated with a reduced risk of severe hypoxemia (odds ratio, 0.290 [95% CI, 0.125 to 0.62]). CONCLUSIONS: Use of a bronchial blocker was associated with a lower risk of hypoxemia in young children undergoing one-lung ventilation.

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.

A Retrospective Evaluation of Airway Anatomy in Young Children and Implications for One-Lung Ventilation.

OBJECTIVE: One-lung ventilation (OLV) in children remains a niche practice with few studies to guide best practices. The objective of this study was to describe lower airway anatomy relevant to establishment of OLV in young children. DESIGN: Retrospective, observational study using pre-existing studies in the electronic health record. SETTING: Single institution, academic medical center, tertiary-care hospital. PARTICIPANTS: Pediatric patients <8 years old. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Chest computed tomographic scans of 111 children 4 days to 8 years of age were reviewed. Measurements were taken from the thyroid isthmus to the carina, carina to first lobar branch on the left and right, diameter of the trachea at the carina, and diameter of the left and right mainstem bronchi. Dimensions were correlated with the outer diameter of endotracheal tubes and bronchial blockers. The left mainstem bronchus is consistently smaller than the right. Lung isolation using a mainstem technique on the left should use an endotracheal tube a half size smaller than would be used for tracheal intubation. The length from the carina to the first lobar branch on the left is consistently 3 times longer than on the right. Further, age-delineated bronchial diameters suggest that the clinician should transition from a 5F to a 7F Arndt bronchial blocker at 3-to-4 years of age. CONCLUSION: A more detailed and accurate understanding of pediatric lower airway anatomy may assist the clinician in successfully performing OLV in young children.

An Update on One-Lung Ventilation in Children.

One-lung ventilation in children continues to present technical and sometimes physiologic challenges to the clinician. The rarity of these cases at any single institution, however, has led to very few prospective trials to guide best practices. As a result, most clinicians continue to be guided by local tradition and preference. That said, the development of new bronchial blockers such as the EZ-Blocker or blocking devices such as the Univent tube have continued to evolve the practice of lung isolation in children. Further, the development of a variety of extraluminal blocker techniques has led to innovations in practice through a relatively diverse landscape of published case series offering different approaches to one-lung ventilation during the past 15 years. The Arndt bronchial blocker continues to represent the most well documented of these devices. Additionally, recent advances have occurred in our understanding of the relevant anatomic constraints of the lower pediatric airway. This review is intended to provide a comprehensive and practical update to practicing pediatric anesthesiologists to further their understanding of the modern practice of one-lung ventilation for thoracic surgery in children.

Bronchial Blocker Entrapment in a 7-Month-Old Infant: A Case Report.

We present the case of a 7-month-old infant undergoing thoracotomy and left lower lobe lobectomy who experienced a significant complication related to lung isolation with a bronchial blocker. Despite good isolation and seemingly appropriate positioning, the bronchial blocker became entrapped within the staple line at the bronchial stump. Fortunately, the surgeon was able to free the blocker. Going forward, we recommend clinicians be vigilant in positioning the blocker just distal to the carina in all cases and, further, consider retracting the blocker into the trachea before surgical intervention on the airway to avoid inadvertent entrapment of the device.

Experience with a "Feed and Swaddle" program in infants up to six months of age.

BACKGROUND: Feed and swaddle is a technique in which an infant is fed and allowed to fall asleep to facilitate diagnostic imaging. This study reviews our experience and diagnostic success in premature and term infants up to 6 months old undergoing brain magnetic resonance imaging (MRI) using a feed and swaddle technique and with comparable patients imaged under anesthesia. METHODS: We reviewed the charts of all infants ≤6 months who underwent brain MRI at our institution between 1 January 2013 and 31 March 2016. We recorded and analyzed demographic information, scan indication, scan length, prematurity status, anesthetic technique if used, complications, and diagnostic success or failure. RESULTS: One hundred and sixty-four term infants underwent brain MRI using a feed and swaddle technique. The success rate in term infants <90 days was 91.1% (113/124) versus 95.0% (38/40) in infants ≥90 days and ≤181 days old. Fifty-three premature infants underwent feed and swaddle for brain MRI with a diagnostic success rate of 92.5% (49/53). No complications were noted in any feed and swaddle patients. Those who received anesthesia had a diagnostic success rate of 100% (70/70) but experienced complications including hypoxemia, 14.3% (10/70); hypothermia, 18.9% (10/53); bradycardia, 10.1% (7/69); and hypotension, 4.2% (3/70). CONCLUSION: Given the high rate of success and absence of complications with feed and swaddle in children ≤6 months for brain MRI and the presence of anesthesia-related complications, most infants should undergo a trial of feed and swaddle prior to undergoing brain MRI with anesthesia.

Anesthesia for Percutaneous Radiofrequency Tumor Ablation (PRFA): A Review of Current Practice and Techniques.

Percutaneous radiofrequency ablation (PRFA) of solid tumors is a minimally invasive procedure used to treat primary or metastatic cancer lesions via needle targeted thermal energy transfer. Some of the most common tumor lesions treated using PRFA include those within the liver, lungs and kidneys. Additionally, bone, thyroid, and breast lesions can also be treated. In most cases, this procedure is performed outside of the operating room in a specialized radiology suite. As a result, the clinician must adapt in many cases to the specific environmental issues attendant to providing anesthesia outside the operating room, including the lack of availability of an anesthesia machine in some cases, and frequently a lack of adequate scavenging and other specialized monitoring and equipment. At this time, routine practice and anesthetic prescriptions for PRFA can vary widely, ranging from patients receiving local anesthesia alone, to monitored anesthesia care, to regional anesthesia, to combined regional and general anesthesia. The choice of anesthetic technique will depend on tumor location and practitioner experience. This review aims to summarize the current state of the art in terms of anesthetic techniques for patients undergoing PRFA of solid tumors.

Assessment of Common Criteria for Awake Extubation in Infants and Young Children.

BACKGROUND: Practice patterns surrounding awake extubation of pediatric surgical patients remain largely undocumented. This study assessed the value of commonly used predictors of fitness for extubation to determine which were most salient in predicting successful extubation following emergence from general anesthesia with a volatile anesthetic in young children. METHODS: This prospective, observational study was performed in 600 children from 0 to 7 yr of age. The presence or absence of nine commonly used extubation criteria in children were recorded at the time of extubation including: facial grimace, eye opening, low end-tidal anesthetic concentration, spontaneous tidal volume greater than 5 ml/kg, conjugate gaze, purposeful movement, movement other than coughing, laryngeal stimulation test, and oxygen saturation. Extubations were graded as Successful, Intervention Required, or Major Intervention Required using a standard set of criteria. The Intervention Required and Major Intervention Required outcomes were combined as a single outcome for analysis of predictors of success. RESULTS: Successful extubation occurred in 92.7% (556 of 600) of cases. Facial grimace odds ratio, 1.93 (95% CI, 1.03 to 3.60; P = 0.039), purposeful movement odds ratio, 2.42 (95% CI, 1.14 to 5.12; P = 0.022), conjugate gaze odds ratio, 2.10 (95% CI, 1.14 to 4.01; P = 0.031), eye opening odds ratio, 4.44 (95% CI, 1.06 to 18.64; P= 0.042), and tidal volume greater than 5 ml/kg odds ratio, 2.66 (95% CI, 1.21 to 5.86; P = 0.015) were univariately associated with the Successful group. A stepwise increase in any one, in any order, of these five predictors being present, from one out of five and up to five out of five yielded an increasing positive predictive value for successful extubation of 88.3% (95% CI, 82.4 to 94.3), 88.4% (95% CI, 83.5 to 93.3), 96.3% (95% CI, 93.4 to 99.2), 97.4% (95% CI, 94.4 to 100), and 100% (95% CI, 90 to 100). CONCLUSIONS: Conjugate gaze, facial grimace, eye opening, purposeful movement, and tidal volume greater than 5 ml/kg were each individually associated with extubation success in pediatric surgical patients after volatile anesthetic. Further, the use of a multifactorial approach using these predictors, may lead to a more rational and robust approach to successful awake extubation.