Extracorporeal Membrane Oxygenation for COVID-19-Associated Multisystem Inflammatory Syndrome in a 5-year-old.

Severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) is associated with multisystem inflammatory syndrome in children (MIS-C) that ranges from mild symptoms to cardiopulmonary collapse. A 5-year-old girl presented with shock and a rapid decline in left ventricular function requiring intubation. SARS-CoV-2 was diagnosed by viral Polymerase Chain Reaction (PCR), and she received remdesivir and COVID-19 convalescent plasma. Initial echocardiogram (ECHO) demonstrated low normal left ventricular function and mild left anterior descending coronary artery dilation. She remained hypotensive, despite high-dose epinephrine and norepinephrine infusions as well as stress-dose hydrocortisone. Admission SARS-CoV-2 IgG assay was positive, meeting the criteria for MIS-C. An ECHO 9 hours after admission demonstrated a severe decline in left ventricular function. Due to severe cardiogenic shock, she was cannulated for venoarterial extracorporeal support (ECMO). During her ECMO course, she was treated with remdesivir, intravenous methylprednisolone, intravenous immunoglobulin, and anakinra. She was decannulated on ECMO day 7, extubated the following day, and discharged home 2 weeks later without respiratory or cardiac support. The use of ECMO for cardiopulmonary support for pediatric patients with MIS-C is feasible and should be considered early as part of the treatment algorithm for patients with severe cardiopulmonary dysfunction.

Danger in the vapor? ECMO for adolescents with status asthmaticus after vaping.

Introduction: Electronic nicotine delivery systems (ENDS) use is on the rise in the adolescent and young adult populations, especially in the wake of sweet flavored ENDS solutions and youth-targeted marketing. While the extent of effect of ENDS use and aerosolized flavorings on airway epithelium is not known, there remains significant concern that use of ENDS adversely affects airway epithelial function, particularly in populations with asthma.Case Study: In this case series, we review two cases of adolescents with history of recent and past ENDS use and asthma who required veno-venous extracorporeal membrane oxygenation (VV-ECMO) for status asthmaticus in the year 2018.Results: Both patients experienced hypercarbic respiratory failure requiring VV-ECMO secondary to their status asthmaticus, with slow recovery on extensive bronchodilator and steroid regimens. They both recovered back to respiratory baseline and were counseled extensively on cessation of ENDS use.Conclusion: While direct causation by exposure to ENDS cannot be determined, exposure likely contributed to symptoms. Based on the severity of these cases and their potential relationship with ENDS use, we advocate for increased physician screening of adolescents for ENDS use, patient and parent education on the risks of use, and family cessation counseling.

Ventilator triggering.

Allowing spontaneous respiration during mechanical ventilation requires that the ventilator system can interpret a trigger signal from the patient and then deliver a synchronous breath. The majority of current ventilators are triggered by preset changes in pressure or flow detected in the system as a patient is initiating a breath. However, other triggers such as chest wall motion, waveform alteration, and diaphragmatic electromyograms have also been utilized. The time between initiation of a breath by a patient and delivery of a breath by the ventilator is known as trigger delay. Most trigger delay is inherent in the mechanics of the patient-ventilator interaction. However, recent advances in technology have captured a neural signal from the diaphragm to trigger the ventilator to deliver a breath, reducing trigger delay. Understanding trigger delay is important as it may lead to increased work of breathing and patient-ventilator asynchrony. Types of asynchrony related to the triggering phase are ineffective triggering, double triggering, and autotriggering. The presence of asynchrony has been shown to have deleterious effects on patients, including duration of mechanical ventilation and increased length of hospital stay. Recognizing asynchrony and understanding how to manipulate the trigger variable will reduce adverse effects on patients.

Validation of volume delivery with the use of heliox in mechanical ventilation.

Using a mixture of helium and oxygen (heliox) while mechanically ventilating patients to relieve lower airway obstruction is commonly practiced in intensive care units. The use of heliox with commercially available mechanical ventilators is usually accomplished by connecting the heliox mixture to the air inlet of the ventilator. Since most ventilators do not compensate for the difference in gas densities, particular attention to the delivered tidal volume (V T ) is required. We utilized a commercially available mechanical ventilator with an internal blending system that is capable of delivering heliox instead of medical air. It identifies and compensates for the gas mixture, theoretically enhancing stability in delivered and monitored parameters. Intubated, sedated male domestic pigs (n = 7) were ventilated with a mechanical ventilator equipped with an internal heliox blending system utilizing pressure assist control, pressure regulated volume control, and pressure support ventilation modes. Accuracy of volume delivery was assessed by comparing delivered V T measured at the patient wye using the variable orifice flow sensor connected to the ventilator and a heated 0-35 L/min pneumotachograph that was calibrated for flow, pressure, and volume, with a 0.80/0.20 heliox mix and 0.50 oxygen. A paired t-test was utilized with a P < 0.05. Pigs mean weight 9.0 ± 0.9 kg. Mean exhaled tidal volume for all modes and was 66 ± 16 mL. When comparing all modes for the 0.50 oxygen to the heliox mix, we found that exhaled tidal volume % difference increased when using heliox ( P ≤ 0.037). This study confirms that clinicians should be vigilant in monitoring delivered V T using a commercially available ventilator equipped with an internal heliox blending system. Accuracy of delivered V T can vary greatly with the use of heliox in this system, as well as other configurations.

Neurally triggered breaths have reduced response time, work of breathing, and asynchrony compared with pneumatically triggered breaths in a recovering animal model of lung injury.

OBJECTIVE: Our objective was to compare response time, pressure time product as a reflection of work of breathing, and incidence and type of asynchrony in neurally vs. pneumatically triggered breaths in a spontaneously breathing animal model with resolving lung injury. DESIGN: Prospective animal study. SETTING: Experimental laboratory. SUBJECTS: Male Yorkshire pigs. INTERVENTIONS: Intubated, sedated pigs were ventilated using neurally adjusted ventilatory assist and pressure support ventilation with healthy and sick/recruited lungs. After injury, the lung was recruited using a computer-driven protocol. Respiratory mechanics were determined using a forced oscillation technique, and airway flow and pressure waveforms were acquired using a pneumotachograph. MEASUREMENTS AND MAIN RESULTS: Waveforms were analyzed for trigger delay, pressure time product, and asynchrony. Trigger delay was defined as the time interval (ms) from initiation of a breath to the beginning of ventilator pressurization. Pressure time product was measured as the area of the pressure curve for animal effort (area A) and ventilator response (area B). Asynchrony was classified according to triggering problems, adequacy of flow delivery, and adequate breath termination. Mean values were compared using the Wilcoxon signed-ranks test (p < .05). Trigger delay (ms) was less in neurally triggered breaths (pressure support ventilation healthy 104 ± 27 vs. neurally adjusted ventilatory assist healthy 72 ± 30, pressure support ventilation sick/recruited 77 ± 18 vs. neurally adjusted ventilatory assist sick/recruited 38 ± 18, p < .01). Pressure time product areas A and B were decreased for neurally triggered breaths compared with pressure support ventilation in both healthy and recruited animals (p ≤ .02). Overall, the percentage of asynchrony was less for neurally adjusted ventilatory assist breaths in the recruited animals (pressure support ventilation 27% and neurally adjusted ventilatory assist 6%). CONCLUSIONS: Neurally triggered breaths have reduced asynchrony, trigger delay, and pressure time product, which may indicate reduced work of breathing associated with less effort to trigger the ventilator and faster response to effort. Further study is required to demonstrate if these differences will lead to decreased days of ventilation and less use of sedation in patients.

Neurally triggered breaths reduce trigger delay and improve ventilator response times in ventilated infants with bronchiolitis.

PURPOSE: Neurally adjusted ventilatory assist (NAVA) is a mode of ventilation designed to improve patient-ventilator interaction by interpreting a neural signal from the diaphragm to trigger a supported breath. We hypothesized that neurally triggered breaths would reduce trigger delay, ventilator response times, and work of breathing in pediatric patients with bronchiolitis. METHODS: Subjects with a clinical diagnosis of bronchiolitis were studied in volume support (pneumatic trigger) and NAVA (pneumatic and neural trigger) in a crossover design. Airway flow and pressure waveforms were obtained with a pneumotachograph and computerized digital recorder and were recorded for 120 s for each experiment. RESULTS: Neurally triggered breaths had less trigger delay (ms) (40 ± 27 vs. 98 ± 34; p < 0.001) and reduced ventilator response times (ms) (15 ± 7 vs. 36 ± 25; p < 0.001) compared with pneumatically triggered breaths. Neurally triggered breaths had reduced pressure-time product (PTP) area A (cmH(2)O * s), the area of the pressure curve from initiation of breath to start of ventilator pressurization (0.013 ± 0.010; p < 0.001), and reduced PTP area B (cmH(2)O * s), the area of the pressure curve from start of ventilator pressurization to return of baseline pressure (0.008 ± 0.006 vs. 0.023 ± 0.009; p = 0.003). Reduced PTP may indicate decreased work of breathing. CONCLUSION: Neurally triggered breaths reduce trigger delay, improve ventilator response times, and may decrease work of breathing in children with bronchiolitis. Further analysis is required to determine if neurally triggered breaths will improve patient-ventilator synchrony.

Single-institution experience with interhospital extracorporeal membrane oxygenation transport: A descriptive study.

OBJECTIVE: Patients with refractory cardiopulmonary failure may benefit from extracorporeal membrane oxygenation, but extracorporeal membrane oxygenation is not available in all medical centers. We report our institution's nearly 20-yr experience with interhospital extracorporeal membrane oxygenation transport. DESIGN: Retrospective review. SETTING: Quaternary care children's hospital. PATIENTS: All patients undergoing interhospital extracorporeal membrane oxygenation transport by the Arkansas Children's Hospital extracorporeal membrane oxygenation team. INTERVENTIONS: Data (age, weight, diagnosis, extracorporeal membrane oxygenation course, hospital course, mode of transport, and outcome) were obtained and compared with the most recent Extracorporeal Life Support Organization Registry report. RESULTS: Interhospital extracorporeal membrane oxygenation transport was provided to 112 patients from 1990 to 2008. Eight were transferred between outside facilities (TAXI group); 104 were transported to our hospital (RETURN group). Transport was by helicopter (75%), ground (12.5%), and fixed wing (12.5%). No patient died during transport. Indications for extracorporeal membrane oxygenation in RETURN patients were cardiac failure in 46% (48 of 104), neonatal respiratory failure in 34% (35 of 104), and other respiratory failure in 20% (21 of 104). Overall survival from extracorporeal membrane oxygenation for the RETURN group was 71% (74 of 104); overall survival to discharge was 58% (61 of 104). Patients with cardiac failure had a 46% (22 of 48) rate of survival to discharge. Neonates with respiratory failure had an 80% (28 of 35) rate of survival to discharge. Other patients with respiratory failure had a 62% (13 of 21) rate of survival to discharge. None of these survival rates were statistically different from survival rates for in-house extracorporeal membrane oxygenation patients or for survival rates reported in the international Extracorporeal Life Support Organization Registry (p > .1 for all comparisons). CONCLUSIONS: Outcomes of patients transported by an experienced extracorporeal membrane oxygenation team to a busy extracorporeal membrane oxygenation center are very comparable to outcomes of nontransported extracorporeal membrane oxygenation patients as reported in the Extracorporeal Life Support Organization registry. As has been previously reported, interhospital extracorporeal membrane oxygenation transport is feasible and can be accomplished safely. Other experienced extracorporeal membrane oxygenation centers may want to consider developing interhospital extracorporeal membrane oxygenation transport capabilities to better serve patients in different geographic regions.