Negative pressure suction test: An intraoperative airway maneuver to assess effectiveness of surgical correction of tracheobronchomalacia.

BACKGROUND: Surgical correction of tracheobronchomalacia (TBM) has evolved greatly over the past decade, with select pediatric institutions establishing dedicated surgery and anesthesia teams to navigate the complexities and challenges of surgical airway repairs. Although anesthetic techniques have evolved internally over many years to improve patient safety and outcomes, many of these methods remain undescribed in literature. TECHNIQUE: In this article, we describe the intraoperative negative pressure suction test. This simulates the negative pressure seen in awake and spontaneously breathing patients, including the higher pressures seen during coughing which induce airway collapse in patients with TBM. Also known as the Munoz maneuver in surgical literature, this test has been performed on over 300 patients since 2015. DISCUSSION: The negative pressure suction test allows for controlled intraoperative assessment of surgical airway repairs, replaces the need for risky intraoperative wake-up tests, increases the chances of a successful surgical repair, and improves anesthetic management for emergence and extubation. We provide a guide on how to perform the test and videos demonstrating its efficacy in intraoperative airway evaluation. CONCLUSIONS: As surgeries to repair TBM become more prevalent in other pediatric institutions, we believe that pediatric patients and anesthesia providers will benefit from the insights and methods described here.

Population Pharmacokinetics of Intraperitoneal Bupivacaine Using Manual Bolus Atomization Versus Micropump Nebulization and Morphine Requirements in Young Children.

BACKGROUND: Intraperitoneal (IP) administration of local anesthetics is used in adults and children for postoperative analgesia after laparoscopic surgery. Population pharmacokinetics (PK) of IP bupivacaine has not been determined in children. Objectives of this study were (1) to develop a population PK model to compare IP bupivacaine administered via manual bolus atomization and micropump nebulization and (2) to assess postoperative morphine requirements after intraoperative administration. We hypothesized similar PK profiles and morphine requirements for both delivery methods. METHODS: This was a prospective, sequential, observational study. After institutional review board (IRB) approval and written informed parental consent, 67 children 6 months to 6 years of age undergoing robot-assisted laparoscopic urological surgery received IP bupivacaine at the beginning of surgery. Children received a total dose of 1.25 mg/kg bupivacaine, either diluted in 30-mL normal saline via manual bolus atomization over 30 seconds or undiluted bupivacaine 0.5% via micropump nebulization into carbon dioxide (CO2) insufflation tubing over 10-17.4 minutes. Venous blood samples were obtained at 4 time points between 1 and 120 minutes intraoperatively. Samples were analyzed by liquid chromatography with mass spectrometry. PK parameters were calculated using noncompartmental and compartmental analyses. Nonlinear regression modeling was used to estimate PK parameters (primary outcomes) and Mann-Whitney U test for morphine requirements (secondary outcomes). RESULTS: Patient characteristics between the 2 delivery methods were comparable. No clinical signs of neurotoxicity or cardiotoxicity were observed. The range of peak plasma concentrations was 0.39-2.44 µg/mL for the manual bolus atomization versus 0.25-1.07 µg/mL for the micropump nebulization. IP bupivacaine PK was described by a 1-compartment model for both delivery methods. Bupivacaine administration by micropump nebulization resulted in a significantly lower Highest Plasma Drug Concentration (Cmax) and shorter time to reach Cmax (Tmax) (P < .001) compared to manual bolus atomization. Lower plasma concentrations with less interpatient variability were observed and predicted by the PK model for the micropump nebulization (P < .001). Adjusting for age, weight, and sex as covariates, Cmax and area under the curve (AUC) were significantly lower with micropump nebulization (P < .001). Regardless of the delivery method, morphine requirements were low at all time points. There were no differences in cumulative postoperative intravenous/oral morphine requirements between manual bolus atomization and micropump nebulization (0.14 vs 0.17 mg/kg; P = .85) measured up to 24 hours postoperatively. CONCLUSIONS: IP bupivacaine administration by micropump nebulization demonstrated lower plasma concentrations, less interpatient variability, low risk of toxicity, and similar clinical efficacy compared to manual bolus atomization. This is the first population PK study of IP bupivacaine in children, motivating future randomized controlled trials to determine efficacy.

Effect of Posterior Tracheopexy on Risk of Recurrence in Children after Recurrent Tracheo-Esophageal Fistula Repair.

BACKGROUND: A recurrent tracheo-esophageal fistula can complicate esophageal atresia and tracheo-esophageal fistula (TEF) repair in children. Therapeutic approaches and the rate of recurrence vary widely. Most reports are limited by small cohorts and short-term follow-up, and rates of re-recurrence are substantial, making it difficult to select the treatment of choice. We aimed to review our experience with the treatment of recurrent TEF using posterior tracheopexy, focusing on operative risks and long-term outcomes. STUDY DESIGN: We conducted a retrospective review of patients with esophageal atresia TEF with recurrent TEF treated at 2 institutions from 2011 to 2020. We approach recurrent TEFs surgically. Once the TEF is divided and repaired, the membranous trachea is sutured to the anterior longitudinal ligament of the spine (posterior tracheopexy) and the esophagus is rotated into the right chest (rotational esophagoplasty), separating the suture lines widely. To detect re-recurrence, patients undergo endoscopic surveillance during follow-up. RESULTS: Sixty-two patients with a recurrent TEF were surgically treated (posterior tracheopexy/rotational esophagoplasty) at a median age of 14 months. All had significant respiratory symptoms. On referral, 24 had earlier failed endoscopic and/or surgical attempts at repair. Twenty-nine required a concomitant esophageal anastomotic stricturoplasty or stricture resection. Postoperative morbidity included 3 esophageal leaks, and 1 transient vocal cord dysfunction. We have identified no recurrences, with a median follow-up of 2.5 years, and all symptoms have resolved. CONCLUSIONS: The surgical treatment of recurrent TEFs that incorporates a posterior tracheopexy and rotational esophagoplasty is highly effective for preventing re-recurrence with low perioperative morbidity.

Intraoperative Recurrent Laryngeal Nerve Monitoring During Pediatric Cardiac and Thoracic Surgery: A Mini Review.

Objective: Review techniques for intraoperative recurrent laryngeal nerve (RLN) monitoring during pediatric surgery for esophageal atresia, tracheoesophageal fistula, tracheobronchomalacia, and cardiac surgery. Summary Background Data: Literature was reviewed for reports of intraoperative recurrent laryngeal nerve monitoring in cervical, thoracic, and cardiac surgical procedures which place the RLNs at risk for injury. Methods: Review paper. Results: The RLN is at risk during pediatric surgery for esophageal atresia, tracheoesophageal fistula, tracheobronchomalacia, and cardiac surgery. Intraoperative nerve monitoring has decreased rates of RLN injury in thyroid surgery. Intraoperative RLN monitoring techniques appropriate for pediatric surgery are discussed, including endotracheal tubes with integrated surface electrodes, adhesive surface electrodes for smaller endotracheal tubes, endolaryngeal electrodes, and automatic periodic continuous intra-operative stimulation. Conclusions: Multiple techniques exist to monitor the RLN in children undergoing cervical, cardiac, and thoracic surgery. Monitoring the RLN during procedures that place the RLNs at risk may help decrease the rate of RLN injury.