Face mask versus nasal prong or nasopharyngeal tube for neonatal resuscitation in the delivery room: a systematic review and meta-analysis.

IMPORTANCE: The current neonatal resuscitation guidelines recommend positive pressure ventilation via face mask or nasal prongs at birth. Using a nasal interface may have the potential to improve outcomes for newborn infants. OBJECTIVE: To determine whether nasal prong/nasopharyngeal tube versus face mask during positive pressure ventilation of infants born <37 weeks' gestation in the delivery room reduces in-hospital mortality and morbidity. DATA SOURCES: MEDLINE (through PubMed), Google Scholar and EMBASE, Clinical Trials.gov and the Cochrane Central Register of Controlled Trials through August 2019. STUDY SELECTION: Randomised controlled trials comparing nasal prong/nasopharyngeal tube versus face mask during positive pressure ventilation of infants born <37 weeks' gestation in the delivery room. DATA ANALYSIS: Risk of bias was assessed using the Covidence Collaboration Tool, results were pooled into a meta-analysis using a random effects model. MAIN OUTCOME: In-hospital mortality. RESULTS: Five RCTs enrolling 873 infants were combined into a meta-analysis. There was no statistical difference in in-hospital mortality (risk ratio (RR 0.98, 95% CI 0.63 to 1.52, p=0.92, I2=11%), rate of chest compressions in the delivery room (RR 0.37, 95% CI 0.10 to 1.33, p=0.13, I2=28%), rate of intraventricular haemorrhage (RR 1.54, 95% CI 0.88 to 2.70, p=0.13, I2=0%) or delivery room intubations in infants ventilated with a nasal prong/tube (RR 0.63, 95% CI 0.39,1.02, p=0.06, I2=52%). CONCLUSION: In infants born <37 weeks' gestation, in-hospital mortality and morbidity were similar following positive pressure ventilation during initial stabilisation with a nasal prong/tube or a face mask.

Coronavirus Disease 2019: Anesthesia Machine Circuit Pressure During Use as an Improvised Intensive Care Unit Ventilator.

BACKGROUND: Use of anesthesia machines as improvised intensive care unit (ICU) ventilators may occur in locations where waste anesthesia gas suction (WAGS) is unavailable. Anecdotal reports suggest as much as 18 cm H2O positive end-expiratory pressure (PEEP) being inadvertently applied under these circumstances, accompanied by inaccurate pressure readings by the anesthesia machine. We hypothesized that resistance within closed anesthesia gas scavenging systems (AGSS) disconnected from WAGS may inadvertently increase circuit pressures. METHODS: An anesthesia machine was connected to an anesthesia breathing circuit, a reference manometer, and a standard bag reservoir to simulate a lung. Ventilation was initiated as follows: volume control, tidal volume (TV) 500 mL, respiratory rate 12, ratio of inspiration to expiration times (I:E) 1:1.9, fraction of inspired oxygen (Fio2) 1.0, fresh gas flow (FGF) rate 2.0 liters per minute (LPM), and PEEP 0 cm H2O. After engaging the ventilator, PEEP and peak inspiratory pressure (PIP) were measured by the reference manometer and the anesthesia machine display simultaneously. The process was repeated using prescribed PEEP levels of 5, 10, 15, and 20 cm H2O. Measurements were repeated with the WAGS disconnected and then were performed again at FGF of 4, 6, 8, 10, and 15 LPM. This process was completed on 3 anesthesia machines: Dräger Perseus A500, Dräger Apollo, and the GE Avance CS2. Simple linear regression was used to assess differences. RESULTS: Utilizing nonparametric Bland-Altman analysis, the reference and machine manometer measurements of PIP demonstrated median differences of -0.40 cm H2O (95% limits of agreement [LOA], -1.00 to 0.55) for the Dräger Apollo, -0.40 cm H2O (95% LOA, -1.10 to 0.41) for the Dräger Perseus, and 1.70 cm H2O (95% LOA, 0.80-3.00) for the GE Avance CS2. At FGF 2 LPM and PEEP 0 cm H2O with the WAGS disconnected, the Dräger Apollo had a difference in PEEP of 0.02 cm H2O (95% confidence interval [CI], -0.04 to 0.08; P = .53); the Dräger Perseus A500, <0.0001 cm H2O (95% CI, -0.11 to 0.11; P = 1.00); and the GE Avance CS2, 8.62 cm H2O (95% CI, 8.55-8.69; P < .0001). After removing the hose connected to the AGSS and the visual indicator bag on the GE Avance CS2, the PEEP difference was 0.12 cm H2O (95% CI, 0.059-0.181; P = .0002). CONCLUSIONS: Displayed airway pressure measurements are clinically accurate in the setting of disconnected WAGS. The Dräger Perseus A500 and Apollo with open scavenging systems do not deliver inadvertent continuous positive airway pressure (CPAP) with WAGS disconnected, but the GE Avance CS2 with a closed AGSS does. This increase in airway pressure can be mitigated by the manufacturer's recommended alterations. Anesthesiologists should be aware of the potential clinically important increases in pressure that may be inadvertently delivered on some anesthesia machines, should the WAGS not be properly connected.

ResUHUrge: A Low Cost and Fully Functional Ventilator Indicated for Application in COVID-19 Patients.

Although the cure for the SARS-CoV-2 virus (COVID-19) will come in the form of pharmaceutical solutions and/or a vaccine, one of the only ways to face it at present is to guarantee the best quality of health for patients, so that they can overcome the disease on their own. Therefore, and considering that COVID-19 generally causes damage to the respiratory system (in the form of lung infection), it is essential to ensure the best pulmonary ventilation for the patient. However, depending on the severity of the disease and the health condition of the patient, the situation can become critical when the patient has respiratory distress or becomes unable to breathe on his/her own. In that case, the ventilator becomes the lifeline of the patient. This device must keep patients stable until, on their own or with the help of medications, they manage to overcome the lung infection. However, with thousands or hundreds of thousands of infected patients, no country has enough ventilators. If this situation has become critical in the Global North, it has turned disastrous in developing countries, where ventilators are even more scarce. This article shows the race against time of a multidisciplinary research team at the University of Huelva, UHU, southwest of Spain, to develop an inexpensive, multifunctional, and easy-to-manufacture ventilator, which has been named ResUHUrge. The device meets all medical requirements and is developed with open-source hardware and software.

Electrical impedance tomography to titrate positive end-expiratory pressure in COVID-19 acute respiratory distress syndrome.

RATIONALE: Patients with coronavirus disease-19-related acute respiratory distress syndrome (C-ARDS) could have a specific physiological phenotype as compared with those affected by ARDS from other causes (NC-ARDS). OBJECTIVES: To describe the effect of positive end-expiratory pressure (PEEP) on respiratory mechanics in C-ARDS patients in supine and prone position, and as compared to NC-ARDS. The primary endpoint was the best PEEP defined as the smallest sum of hyperdistension and collapse. METHODS: Seventeen patients with moderate-to-severe C-ARDS were monitored by electrical impedance tomography (EIT) and evaluated during PEEP titration in supine (n = 17) and prone (n = 14) position and compared with 13 NC-ARDS patients investigated by EIT in our department before the COVID-19 pandemic. RESULTS: As compared with NC-ARDS, C-ARDS exhibited a higher median best PEEP (defined using EIT as the smallest sum of hyperdistension and collapse, 12 [9, 12] vs. 9 [6, 9] cmH2O, p < 0.01), more collapse at low PEEP, and less hyperdistension at high PEEP. The median value of the best PEEP was similar in C-ARDS in supine and prone position: 12 [9, 12] vs. 12 [10, 15] cmH2O, p = 0.59. The response to PEEP was also similar in C-ARDS patients with higher vs. lower respiratory system compliance. CONCLUSION: An intermediate PEEP level seems appropriate in half of our C-ARDS patients. There is no solid evidence that compliance at low PEEP could predict the response to PEEP.

A novel inline PEEP valve design for differential multi-ventilation.

BACKGROUND: Ventilator sharing is one option to emergently increase ventilator capacity during a crisis but has been criticized for its inability to adjust for individual patient needs. Newer ventilator sharing designs use valves and restrictors to control pressures for each patient. A key component of these designs is an inline Positive End Expiratory Pressure (PEEP) Valve but these are not readily available. Creating an inline PEEP valve by converting a standard bag-valve-mask PEEP valve is possible with the addition of a 3D printed collar. METHODS: This was a feasibility study assessing the performance and safety of a method for converting a standard PEEP valve into an inline PEEP valve. A collar was designed and printed that covers the exhaust ports of the valve and returns exhaled gases to the ventilator. RESULTS: The collar piece was simple to print and easily assembled with the standard PEEP valve. In bench testing it successfully created differential pressures in 2 simulated expiratory limbs without leaking to the atmosphere at pressures greater than 60 cm of H2O. CONCLUSION: Our novel inline PEEP valve design shows promise as an option for building a safer ventilator sharing system.

Invasive mechanical ventilation using a bilevel PAP ST device in a healthy swine model.

PURPOSE: The Coronavirus Disease 2019 (COVID-19) pandemic may cause an acute shortage of ventilators. Standard noninvasive bilevel positive airway pressure devices with spontaneous and timed respirations (bilevel PAP ST) could provide invasive ventilation but evidence on their effectiveness in this capacity is limited. We sought to evaluate the ability of bilevel PAP ST to effect gas exchange via invasive ventilation in a healthy swine model. METHODS: Two single limb respiratory circuits with passive filtered exhalation were constructed and evaluated. Next, two bilevel PAP ST devices, designed for sleep laboratory and home use, were tested on an intubated healthy swine model using these circuits. These devices were compared to an anesthesia ventilator. RESULTS: We evaluated respiratory mechanics, minute ventilation, oxygenation, and presence of rebreathing for all of these devices. Both bilevel PAP ST devices were able to control the measured parameters. There were noted differences in performance between the two devices. Despite these differences, both devices provided effective invasive ventilation by controlling minute ventilation and providing adequate oxygenation in the animal model. CONCLUSIONS: Commercially available bilevel PAP ST can provide invasive ventilation with a single limb respiratory circuit and in-line filters to control oxygenation and ventilation without significant rebreathing in a swine model. Further study is needed to evaluate safety and efficacy in clinical disease models. In the setting of a ventilator shortage during the COVID-19 pandemic, and in other resource-constrained situations, these devices may be considered as an effective alternative means for invasive ventilation.

PEEP/ FIO2 ARDSNet Scale Grouping of a Single Ventilator for Two Patients: Modeling Tidal Volume Response.

BACKGROUND: The COVID-19 pandemic is creating ventilator shortages in many countries that is sparking a conversation about placing multiple patients on a single ventilator. However, on March 26, 2020, six leading medical organizations released a joint statement warning clinicians that attempting this technique could lead to poor outcomes and high mortality. Nevertheless, hospitals around the United States and abroad are considering this technique out of desperation (eg, New York), but there is little data to guide their approach. The overall objective of this study is to utilize a computational model of mechanically ventilated lungs to assess how patient-specific lung mechanics and ventilator settings impact lung tidal volume (VT). METHODS: We developed a lumped-parameter computational model of multiple patients connected to a shared ventilator and validated it against a similar experimental study. We used this model to evaluate how patient-specific lung compliance and resistance would impact VT under 4 ventilator settings of pressure control level, PEEP, breathing frequency, and inspiratory:expiratory ratio. RESULTS: Our computational model predicts VT within 10% of experimental measurements. Using this model to perform a parametric study, we provide proof-of-concept for an algorithm to better match patients in different hypothetical scenarios of a single ventilator shared by > 1 patient. CONCLUSIONS: Assigning patients to preset ventilators based on their required level of support on the lower PEEP/higher [Formula: see text] scale of the National Institute of Health's National Heart, Lung, and Blood Institute ARDS Clinical Network (ARDSNet), secondary to lung mechanics, could be used to overcome some of the legitimate concerns of placing multiple patients on a single ventilator. We emphasize that our results are currently based on a computational model that has not been validated against any preclinical or clinical data. Therefore, clinicians considering this approach should not look to our study as an exact estimate of predicted patient VT values.