Retrograde Tracheal Intubation: Indications, Stages, Technique

Retrograde tracheal intubation occupies an important place in modern clinical practice and experimental studies when performing artificial lung ventilation to maintain vital functions of the human and mammalian body. Retrograde tracheal intubation has a very rich history (more than 50 years), and during this time this method has been repeatedly modified and optimized. This article discusses the indications and contraindications, equipment, stages and techniques of retrograde tracheal intubation.

Applying a Hydrophilic Modified Hollow Fiber Membrane to Reduce Fouling in Artificial Lungs

Membranes for use in high gas exchange lung applications are riddled with fouling. The goal of this research is to create a membrane that can function in an artificial lung until the actual lung becomes available for the patient. The design of the artificial lung is based on new hollow fiber membranes (HFMs), due to which the current devices have short and limited periods of low fouling. By successfully modifying membranes with attached peptoids, low fouling can be achieved for longer periods of time. Hydrophilic modification of porous polysulfone (PSF) membranes can be achieved gradually by polydopamine (PSU-PDA) and peptoid (PSU-PDA-NMEG5). Polysulfone (PSU-BSA-35Mg), polysulfone polydopamine (PSUPDA-BSA-35Mg) and polysulfone polydopamine peptoid (PSU-PDA-NMEG5-BSA35Mg) were tested by potting into the new design of gas exchange modules. Both surfaces of the modified membranes were found to be highly resistant to protein fouling permanently. The use of different peptoids can facilitate optimization of the low fouling on the membrane surface, thereby allowing membranes to be run for significantly longer time periods than has been currently achieved.

Bioengineering Progress in Lung Assist Devices

Artificial lung technology is advancing at a startling rate raising hopes that it would better serve the needs of those requiring respiratory support. Whether to assist the healing of an injured lung, support patients to lung transplantation, or to entirely replace native lung function, safe and effective artificial lungs are sought. After 200 years of bioengineering progress, artificial lungs are closer than ever before to meet this demand which has risen exponentially due to the COVID-19 crisis. In this review, the critical advances in the historical development of artificial lungs are detailed. The current state of affairs regarding extracorporeal membrane oxygenation, intravascular lung assists, pump-less extracorporeal lung assists, total artificial lungs, and microfluidic oxygenators are outlined.

Low Cost Traınıng Models For Videothoracoscopic Surgical Training

Objective: We designed novel practical simulation models for VATS lung nodule palpation and vessel dissection, subsequently evaluated the performances of the residents in our thoracic surgery program to account for an appropriate level of difficulty, and grade the learning experience. Methods: Artificial lung nodules were formed by injecting sheep heart-lung blocks with either cyanoacrylate or construction-grade silicone diluted with synthetic thinner. An artificial lung and vessel environment was formed using a sponge, tube balloon placed inside a tunnel within the sponge and fixed with a flexible glue. Both models were placed in a standard laparoscopy training box; both conventional and minimally invasive surgery instruments were used as applicable per the attendee's discretion. Results: In the lung nodule simulation, among 4 residents (postgraduate year (PGY) 1, 3, 4, and 4) average time to palpating the first nodule was 57 seconds, the average time of whole lung palpation was 7,7 minutes. In the vascular dissection model, five residents (PGY 4, 3, 3, 3, 1) median distance dissected at the first attempt was 3,1 cm (1-4,7), and it was shorter 2,5 cm (2-3,2) in the second attempt. Median dissection duration was shorter in the second attempt (5 vs 3 minutes). All residents were able to complete the dissection of the balloon from the sponge within 9 attempts. Conclusion: Surgical simulation models can be created with minimal resources, allowing for enough difficulty to maintain engagement and progressive skill accomplishment through practice. As clinics shift case volume to minimally invasive procedures, resident exposure to open cases can become more scarce, so simulation training in thoracic surgery can not be perceived as a luxury. It has to be accessible even though the learning environment does not have the resources to invest in virtual reality sets or computerized simulators.

Validation of transcutaneous carbon dioxide monitoring using an artificial lung during adult pulsatile cardiopulmonary bypass

Measurements of transcutaneous carbon dioxide (tcCO2) have been used in multiple venues, such as during procedures utilizing jet ventilation, hyperbaric oxygen therapy, as well as both the adult and neo-natal ICUs. However, tcCO2 measurements have not been validated under conditions which utilize an artificial lung, such cardiopulmonary bypass (CPB). The purpose of this study was to (1) validate the use of tcCO2 using an artificial lung during CPB and (2) identify a location for the sensor that would optimize estimation of PaCO2 when compared to the gold standard of blood gas analysis. tcCO2 measurements ( N = 185) were collected every 30 min during 54 pulsatile CPB procedures. The agreement/differences between the tcCO2 and the PaCO2 were compared by three sensor locations. Compared to the earlobe or the forehead, the submandibular PtcCO2 values agreed best with the PaCO2 and with a median difference of –.03 mmHg (IQR = 5.4, p < 0.001). The small median difference and acceptable IQR support the validity of the tcCO2 measurement. The multiple linear regression model for predicting the agreement between the submandibular tcCO2 and PaCO2 included the SvO2, the oxygenator gas to blood flow ratio, and the native perfusion index ( R2 = 0.699, df = 1, 60; F = 19.1, p < 0.001). Our experience in utilizing tcCO2 during CPB has demonstrated accuracy in estimating PaCO2 when compared to the gold standard arterial blood gas analysis, even during CO2 flooding of the surgical field.