Tracheostomy Practices and Outcomes in Children During Respiratory Extracorporeal Membrane Oxygenation.

OBJECTIVES: Children receiving prolonged extracorporeal membrane oxygenation (ECMO) support may benefit from tracheostomy during ECMO by facilitating rehabilitation; however, the procedure carries risks, especially hemorrhagic complications. Knowledge of tracheostomy practices and outcomes of ECMO-supported children who undergo tracheostomy on ECMO may inform decision-making. DESIGN: Retrospective cohort study. SETTING: ECMO centers contributing to the Extracorporeal Life Support Organization registry. PATIENTS: Children from birth to 18 years who received ECMO support for greater than or equal to 7 days for respiratory failure from January 1, 2015, to December 31, 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Three thousand six hundred eighty-five children received at least 7 days of ECMO support for respiratory failure. The median duration of ECMO support was 13.0 days (interquartile range [IQR], 9.3-19.9 d), and inhospital mortality was 38.7% (1,426/3,685). A tracheostomy was placed during ECMO support in 94/3,685 (2.6%). Of those who received a tracheostomy on ECMO, the procedure was performed at a median 13.2 days (IQR, 6.3-25.9 d) after initiation of ECMO. Surgical site bleeding was documented in 26% of children who received a tracheostomy (12% after tracheostomy placement). Among children who received a tracheostomy, the median duration of ECMO support was 24.2 days (IQR, 13.0-58.7 d); inhospital mortality was 30/94 (32%). Those that received a tracheostomy before 14 days on ECMO were older (median age, 15.8 yr [IQR, 4.7-15.5] vs 11.7 yr [IQR, 11.5-17.3 yr]; p =0.002) and more likely to have been supported on venovenous-ECMO (84% vs 52%; p = 0.001). Twenty-two percent (11/50) of those who received a tracheostomy before 14 days died in the hospital, compared with 19/44 (43%) of those who received a tracheostomy at 14 days or later (p = 0.03). CONCLUSIONS: Tracheostomies during ECMO were uncommon in children. One in four patients who received a tracheostomy on ECMO had surgical site bleeding. Children who had tracheostomies placed after 14 days were younger and had worse outcomes, potentially representing tracheostomy as a "secondary" strategy for prolonged ECMO support.

Bubble bilevel ventilation facilitates gas exchange in anesthetized rabbits.

BACKGROUND: Bubble continuous positive airway pressure is an established therapy for infants in respiratory distress. In resource-limited settings, few treatment options exist for infants requiring further respiratory support. A bubble bilevel device has been developed to provide nonelectric, time-cycled, pressure-limited respiratory support. We compared the efficacy of bubble bilevel ventilation with conventional mechanical ventilation in sedated rabbits. METHODS: Six adult rabbits under inhaled isoflurane general anesthesia were ventilated by alternating intervals of conventional and bubble bilevel ventilation for three 10-15-min periods. During each period, interval arterial blood gas (ABG) measurements were obtained after at least 10 min on the respective mode of ventilation. RESULTS: The bubble bilevel system was able to deliver the following pressures: 20/7, 15/5, 12/5, 8/5 cm H2O. The estimated differences in arterial blood gas values on bubble bilevel vs. ventilator were as follows (normalized values): pH 7.41 vs. 7.40, pCO2 37.7 vs. 40, pO2 97.6 vs. 80. In addition, the bubble bilevel ventilation delivered consistent pressure waveforms without interruption for over 60 min on two rabbits. CONCLUSION: This study demonstrates promising in vivo results on the efficacy of a novel bubble bilevel device, which may prove useful for infants in respiratory distress. IMPACT: Given the lack of personnel, funds or infrastructure to provide neonatal mechanical ventilation in resource-limited settings, additional low-cost, low-tech treatments are necessary to save infant lives. Bubble bilevel ventilation reliably delivers two levels of airway pressure to anesthetized rabbits resulting in normalization of blood gases comparable to those achieved on a traditional ventilator. If proven effective, simple technologies like this device have the potential to significantly impact neonatal mortality due to respiratory distress globally.

Venogram before long-interval repeat cannulation for pediatric extracorporeal membrane oxygenation.

It is rare for children to receive more than one course of support with extracorporeal membrane oxygenation, and in those who do undergo multiple episodes, the interval is usually days to weeks between events. Little data exists on re-cannulation years after an initial extracorporeal membrane oxygenation run, and late repeat cannulation can pose unique challenges. We report the case of a 10-year-old male patient with right jugular vein occlusion due to a previous course of extracorporeal membrane oxygenation as a neonate, who was successfully supported via central cannulation. This case demonstrates the importance of adequate imaging of target vasculature prior to attempting re-cannulation of a previously used vessel. Establishing a thoughtful strategy for late repeat cannulation is essential to achieve safe access in unusual and challenging situations.

Inflammatory Effects of Blood-Air Interface in a Porcine Cardiopulmonary Bypass Model.

Cardiopulmonary bypass (CPB) causes a systemic inflammatory response syndrome (SIRS) associated with multiorgan injury. A model was developed to test whether a blood-air interface (BAI) in the CPB circuit causes blood element activation and inflammation. Ten healthy swine were placed on partial CPB for 2 hours via the cervical vessels and monitored for 96 hours postoperatively. Five pigs (control group) had minimal air exposure in the circuit, while five were exposed to a BAI simulating cardiotomy suction. There were no significant differences in bypass flow or hemodynamics between the groups. In the BAI group, there was an increase in hemolysis after bypass (plasma-free hemoglobin 5.27 ± 1.2 vs. 0.94 ± 0.8 mg/dl; p = 0.01), more aggressive platelet consumption (28% vs. 83% of baseline; p = 0.009), leukocyte consumption (71% vs. 107% of baseline; p = 0.02), and increased granulocyte CD11b expression (409% vs. 106% of baseline; p = 0.009). These data suggest the inflammatory pattern responsible for the CPB-SIRS phenomenon may be driven by blood-air interaction. Future efforts should focus on BAI-associated mechanisms for minimizing blood trauma and inflammation during CPB.

A Model of Pediatric End-Stage Lung Failure in Small Lambs <20 kg.

One in five children with end-stage lung failure (ESLF) die while awaiting lung transplant. No suitable animal model of ESLF exists for the development of artificial lung devices for bridging to transplant. Small lambs weighing 15.7 ± 3.1 kg (n = 5) underwent ligation of the left anterior pulmonary artery (PA) branch, and gradual occlusion of the right main PA over 48 hours. All animals remained hemodynamically stable. Over seven days of disease model conditions, they developed pulmonary hypertension (mean PA pressure 20 ± 5 vs. 33 ± 4 mm Hg), decreased perfusion (SvO2 66 ± 3 vs. 55 ± 8%) with supplemental oxygen requirement, and severe tachypneic response (45 ± 9 vs. 82 ± 23 breaths/min) (all p < 0.05). Severe right heart dysfunction developed (tricuspid annular plane systolic excursion 13 ± 3 vs. 7 ± 2 mm, fractional area change 36 ± 6 vs. 22 ± 10 mm, ejection fraction 51 ± 9 vs. 27 ± 17%, all p < 0.05) with severe tricuspid regurgitation and balloon-shaped dilation of the right ventricle. This model of pediatric ESLF reliably produces pulmonary hypertension, right heart strain, and impaired gas exchange, and will be used to develop a pediatric artificial lung.

Does Surgical Management Alter Outcome in Necrotizing Enterocolitis?

Necrotizing enterocolitis occurs in 14% of infants less than 1000 g. Preoperative management varies widely, and the only absolute indication for surgery is pneumoperitoneum. Multiple biomarkers and scoring systems are under investigation, but clinical practice is still largely driven by surgeon judgment. Outcomes in panintestinal disease are poor, and multiple creative approaches are used to preserve bowel length. Overall, recovery is complicated in the short and long term. Major sequelae are stricture, short gut syndrome, and neurodevelopmental impairment. Resolving controversies in surgical necrotizing enterocolitis care requires multicenter collaboration for centralized data and tissue repositories, benchmarking, and carrying out prospective randomized controlled trials.

Retroperitoneal exploration with Vicryl mesh and fibrin tissue sealant for refractory chylous ascites.

BACKGROUND: Congenital chylous ascites poses a significant challenge in neonatal care, and often results in prolonged, complex hospital stays and increased mortality. Few effective options exist in refractory cases. METHODS: Patients aged 0 to 12 months with refractory chylous ascites underwent retroperitoneal exploration after medical treatment and minimally invasive therapies were unsuccessful. The retroperitoneum was completely exposed via left and right medial visceral rotation and opening the lesser sac. Visible leaks were ligated, and alternating layers of fibrin glue and Vicryl mesh were used to cover the entire retroperitoneum. RESULTS: All 4 patients had resolution of their chylous ascites. None required reoperation or reintervention for chyle leaks. All achieved goal enteral feeds at a median of 29 days postoperatively and were discharged from hospital at a median of 42 days postoperatively. CONCLUSIONS: Management of chylous ascites is extremely challenging in refractory cases. Complete retroperitoneal exposure with fibrin glue and Vicryl mesh application offers a definitive, reliable therapy for achieving cessation of lymphatic leakage and ultimate recovery for patients who fail all nonoperative approaches. STUDY TYPE: Therapeutic. LEVEL OF EVIDENCE: IV.

Evaluation of Continuous Lactate Monitoring Systems within a Heparinized In Vivo Porcine Model Intravenously and Subcutaneously.

We present an animal model used to evaluate the in vivo performance of electrochemical amperometric continuous lactate sensors compared to blood gas instruments. Electrochemical lactate sensors were fabricated, placed into 5 Fr central venous catheters (CVCs), and paired with wireless potentiostat devices. Following in vivo evaluation and calibration, sensors were placed within the jugular and femoral veins of a porcine subject as a preliminary assessment of in vivo measurement accuracy. The mobile electronic circuit potentiostat devices supplied the operational voltage for the sensors, measured the resultant steady-state current, and recorded the sensor response values in internal memory storages. An in vivo time trace of implanted intravenous (IV) sensors demonstrated lactate values that correlated well with the discrete measurements of blood samples on a benchtop point-of-care sensor-based instrument. Currents measured continuously from the implanted lactate sensors over 10 h were converted into lactate concentration values through use of a two-point in vivo calibration. Study shows that intravenously implanted sensors had more accurate readings, faster peak-reaching rates, and shorter peak-detection times compared to subcutaneously placed sensors. IV implanted and subcutaneously placed sensors closer to the upper body (in this case neck) showed faster response rates and more accurate measurements compared to those implanted in the lower portion of the porcine model. This study represents an important milestone not only towards continuous lactate monitoring for early diagnosis and intervention in neonatal patients with congenital heart disease undergoing cardiopulmonary bypass surgeries, but also in the intervention of critical ill patients in the Intensive Care Units or during complex surgical procedures.

Fetal intervention for congenital chylothorax is associated with improved outcomes in early life.

BACKGROUND: Congenital chylothorax (CC) can have devastating consequences for neonates. We sought to determine the outcomes of cases treated at our institution and evaluate the role of fetal intervention. MATERIALS AND METHODS: With Institutional Review Board approval, patients treated at our institution 09/2006-04/2016 with CC were reviewed. History and outcomes were compared between patients undergoing fetal intervention (fetal group) and patients who did not (control group). RESULTS: Twenty-three patients were identified. Mean gestational age at birth was 35 wk. Overall mortality was 30% (7 patients). Nineteen patients (83%) were prenatally diagnosed, and 10 patients (43%) underwent fetal intervention. Birth weight was significantly lower in the fetal group compared to the control group (median interquartile range [IQR]; 2.5 [2.3-3.0] versus 3.3 [2.6-3.7] kg, P = 0.02). Apgar scores were significantly higher in the fetal group than the control group at 1 and 5 min (median [IQR]; 6 [4-8] versus 1 [1-2], P = 0.005 and 8 [7-9] versus 2 [2-6], P = 0.008, respectively). For those patients with prenatal diagnosis of CC and hydrops fetalis, thrombosis and lymphopenia were both improved in the fetal group (thrombosis 0% versus 40%, P = 0.03; lymphocyte nadir [median {IQR}] 1.5 [0.6-2.9] versus 0.1 [0.05-0.2], P = 0.02). Duration of support with mechanical ventilation was significantly shorter in the fetal group (median [IQR]; 1 [0-40] versus 41 [29-75] d, P = 0.04). CONCLUSIONS: Fetal intervention for CC is associated with improved Apgar scores and decreased ventilator days and complications in patients with hydrops fetalis. Fetuses with chylothorax, especially those with hydrops, should be referred to a fetal center for evaluation.

Cut or Do Not Cut? Assessing Perceptions of Safety During Laparoscopic Cholecystectomy Using Surgical Videos.

OBJECTIVE: Bile duct injury remains a serious complication of laparoscopic cholecystectomy despite established criteria for the critical view of safety (CVS). Using surgical videos, we compared surgeons' willingness to divide critical structures based on their assessment of the CVS dissection. DESIGN: Participants reviewed 20 operative videos lasting 1 minute each, edited at various points of the CVS dissection. Participants stated whether the structures were safe to divide, and if not, what steps they would take to achieve an adequate dissection. Videos were independently scored using a validated scale and categorized as an "adequate" or "inadequate" dissection based on the score. Participants were blinded to CVS score and adequacy. Cohen's kappa statistic was used to evaluate inter-rater agreement and responses were compared by univariate analysis. SETTING: University of Michigan, Ann Arbor, Michigan. Tertiary care university hospital. PARTICIPANTS: General surgery residents (n = 13) and faculty (n = 13) at the study institution. RESULTS: There was minimal agreement on willingness to divide critical structures among all participants (κ = 0.25), among faculty (κ = 0.30), and among residents (κ = 0.21). Participants were more willing to divide critical structures when videos showed an adequate CVS dissection (CVS score ≥ 4) than an inadequate dissection (CVS score ≤ 3) (60.4% vs. 16.3%, p = 0.043). For inadequate dissections, participants most commonly recommended further dissection of the hepatocystic triangle (30.8%). There was no significant difference in the rate of unsafe practices (choosing to divide critical structures for videos with an "inadequate" dissection) between faculty and residents (14.2% vs. 18.3%, p = 0.781). CONCLUSIONS: There was minimal agreement on what constituted a safe CVS dissection and there was no difference in the rate of unsafe practices between trainees and faculty. Education may play a more important role than experience when building a culture of safety for laparoscopic cholecystectomy.

Effects of an artificial placenta on brain development and injury in premature lambs.

PURPOSE: We evaluated whether brain development continues and brain injury is prevented during Artificial Placenta (AP) support utilizing extracorporeal life support (ECLS). METHODS: Lambs at EGA 118days (term=145; n=4) were placed on AP support (venovenous ECLS with jugular drainage and umbilical vein reinfusion) for 7days and sacrificed. Early (EGA 118; n=4) and late (EGA 127; n=4) mechanical ventilation (MV) lambs underwent conventional MV for up to 48h and were sacrificed, and early (n=5) and late (n=5) tissue control (TC) lambs were sacrificed at delivery. Brains were harvested, formalin-fixed, rehydrated, and studied by magnetic resonance imaging (MRI). The gyrification index (GI), a measure of cerebral folding complexity, was calculated for each brain. Diffusion-weighted imaging was used to determine fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in multiple structures to assess white matter (WM) integrity. RESULTS: No intracranial hemorrhage was observed. GI was similar between AP and TC groups. ADC and FA did not differ between AP and late TC groups in any structure. Compared to late MV brains, AP brains demonstrated significantly higher ADC (0.45±0.08 vs. 0.27±0.11, p=0.02) and FA (0.61±0.04 vs. 0.44±0.05; p=0.006) in the cerebral peduncles. CONCLUSIONS: After 7days of AP support, WM integrity is preserved relative to mechanical ventilation. TYPE OF STUDY: Research study.

Early appendectomy reduces costs in children with perforated appendicitis.

BACKGROUND: Perforated appendicitis can be managed with early appendectomy, or nonoperative management followed by interval appendectomy. We aimed to identify the strategy with the lowest health care utilization and cost. METHODS: We retrospectively reviewed the medical records of all children ≤18 years old with perforated appendicitis admitted to a single institution between January 2009 and March 2016. After excluding immunosuppressed patients and transfers from outside hospitals, we grouped the remaining patients by early or interval appendectomy. Cost accounting data were obtained from our institutional database. The primary outcome was total hospital cost over 2 y from initial admission for appendicitis. Other outcomes analyzed included initial admission costs, number of admissions, emergency room and clinic visits, percutaneous procedures, cross-sectional and overall imaging studies, and length of stay. RESULTS: A total of 203 children with perforated appendicitis were identified. After exclusion of immunosuppressed patients and outside hospital transfers, 94 patients were included in the study. Thirty-nine underwent early appendectomy and 55 initial nonoperative management; of these, 54 underwent elective interval appendectomy. Five of 55 patients (9%) failed initial nonoperative management and required earlier-than-planned appendectomy. Total cost over 2 y was significantly lower with early appendectomy than initial nonoperative management ($19,300 ± 14,300 versus $26,000 ± 17,500; P = 0.05). Early appendectomy resulted in fewer hospital admissions, clinic visits, invasive procedures, and imaging studies. CONCLUSIONS: Early appendectomy results in lower hospital costs and less health care utilization compared with initial nonoperative management with elective interval appendectomy. A prospective study will shed more light on this question and can assess the role of nonoperative management without interval appendectomy in children with perforated appendicitis.