Material Used in Capnography
One of the obstacles to the utilization of expired CO2 monitoring resides in the disparity of the material used by emergency physicians. To clarify this situation, it is important to distinguish whether the patient is artificially ventilated or breathing spontaneously. As for the rest, the different techniques used for analysis no longer have an implication on clinical results and efficiency.
This statement stands in the case of the traditional distinction between sidestream and mainstream capnography. These two techniques measure CO2 using infrared waves; the sidestream system uses an aspiration pump to transport CO2 from the mouth to the detector situated in the monitor, while the mainstream system measures CO2 directly in a small chamber situated at the mouth of the patient and connected to the monitor by a cable. Traditionally, the sidestream system is used for patients breathing spontaneously as the system is lighter, and the mainstream system, a little bulkier, is connected directly to the endotracheal tube in intubated patients. Technological advances in the last years have fundamentally reduced the differences between mainstream and sidestream systems. New technology is pointing towards the microstream system, which is a sort of 'enhanced sidestream system' in which CO2 travels along a thin tube before reaching the chamber where the detector is located, allowing a smaller transition period between the mouth and the detection chamber and thus a capnography curve that is almost synchronized with the passage of air at the mouth. So, let us have a look at what distinguishes the choice of material, as explained in the second half of the video sequence:
<ul>
	<li>If the physician wishes to monitor a patient in spontaneous ventilation so as to precocely detect apnea (during procedural sedation, or after medical intoxication), then only the form of the curve is essential, the actual value of ETCO2 being of less importance. In this case, he physician can choose between nasal prongs or a capnomask combining oxygen administration and CO2 aspiration, or a thin CO2 aspiration tube that can be placed under a classical mask.</li>
	<li>If the physician wishes to precisely analyse ETCO2 in order to adapt the parameters on a respirator, to verify the correct positioning of an endotracheal tube, or to evaluate the prognosis during cardiac arrest, he must use the material than can be adapted for use with an endotracheal tube (always placed behind the filter so as secretions from the patient do not block the tube).</li>
</ul>
The Capnography Curve
A typical capnography curve during three expirations is given in Figure 1. The curve regains the x-axis (0 value) at each inspiration, as there is virtually no CO2 in inspired air.
 <img src="/files/ftp_upload/2508/2508fig1.jpg" alt="Figure 1" /> 
 Figure 1: alternance inspiration-expiration
Differences Between PaCO2 and ETCO2
It would be eutopic to believe that non-invasive monitoring of expired CO2 can replace in all circumstances the need for arterial blood gas (ABG) measures, considered to be the gold standard for the measurement of PaCO2. All depends on the indications for the measurement of expired CO2 and the patient's cardio-respiratory condition. If the indication is the monitoring of respiratory activity to prevent hypoventilation and apnea during sedation, a simple analysis of the curve is sufficient, whatever the value of ETCO2. On the other hand, if the indication is to monitor the adequate ventilation of a head trauma patient with no history of cardio-respiratory disorders, we can expect the ETCO2 value to be close to the PaO2 value, though the necessity of a precise PaCO2 value imposes at least one ABG sample, which also allows us to confirm that indeed ETCO2 is close to PaCO2 in the present case.
Finally, if we are faced with the case of a patient that is intubated and ventilated due to respiratory distress, ETCO2 values will evidently not be a good approximation of PaCO2. The reason is simple; as soon as there is a disturbance in ventilation-perfusion ratios, regardless of what the cardio-pulmonary disorder present is, an obstacle to the correct elimination of CO2 by the lungs is created. As a result, CO2 accumulates in the blood, and naso-buccal elimination is reduced, creating a PaCO2 - ETCO2 gradient. In this circumstance, it is crucial to know the value of PaCO2 before any interpretation of the ETCO2 value.
The first part of the video sequencedescribes the procedure to be followed for interpreting the difference between PaCO2 and ETCO2. We see that the measure of ETCO2 is obtained immediately and in a non-invasive manner, but at this stage cannot allow the adaptation of the respirator's parameters. This implies having to measure the PaCO2 that can then be compared with the ETCO2. The PaCO2 value remains the referral value for the appreciation of patient ventilation.
<ul>
	<li>If PaCO2 measured is higher than the desired value, for example 60mmHg instead of 40mmHg, this signifies that the patient is hypoventilated. The respirator's parameters can then be adapted; either the respiratory rate or the tidal volume can be increased in order to increase the ventilation and thus decrease PaCO2. The objective consists in reducing the ETCO2 by 20mmHg, regardless of the initial ETCO2 value. For example, it can be possible that the ETCO2 value is 50mmHg when the PaCO2 is measured at 60mmHg, due to a PaCO2 -ETCO2 gradient created by the presence of a cardio-respiratory disease. When the adaptation of the respirator's parameters allows the ETCO2 to drop from 50mmHg to 30mmHg, we can safely suppose that the patient is adequately ventilated with a PaCO2 value having dropped from 60mmHg to 40mmHg.</li>
	<li>Inversely, if the PaCO2 is lower than the target value, the patient is hyperventilated and consequently respiratory rate or tidal volume must be reduced to attain the target value. If PaCO2 is 20 mmHg lower than the targeted value, one has to increase the ETCO2 by 20mmHg through modification of the respirator's parameters.</li>
</ul>
Artifacts and Traps in Capnography.
If the technology for CO2 measurement has become reliable in terms of precision, reproducibility, response time and curve quality, it still presents, as for any monitored parameter, certain limits:
<ul>
	<li>The first limitation is due to lack of correct knowledge concerning the physiopathology of CO2 by the physician, who then is reluctant to use the technique. We hope that this explanation and the video sequences accompanying will help resolve this limitation.</li>
	<li>In the case of the spontaneously breathing patient, the adjunction of oxygenotherapy via the mask will dilute the expired CO2, which will significantly modify the capnogram and the ETCO2 will drop. The video sequence demonstrates this phenomenon.</li>
	<li>If one wishes to monitor for hypoventilation, or an apnea event, during procedural sedation, we expect ETCO2, in correlation to PaCO2, to increase in parallel to hypoventilation of the patient. Paradoxally, a hypoventilation event in a patient breathing spontaneously is translated by a drop in ETCO2, because the patient is then only breathing with a very small tidal volume, which essentially corresponds to the dead volume of the tracheo-bronchal space; and as we know, this space does not participate in gaseous exchange and thus contains very little CO2.</li>
	<li>During mechanical ventilation, the pitfall is that one forgets that ETCO2 does not necessarily reflect PaCO2 (see previous chapter).</li>
</ul>

<ol>
	<li>Gravenstein, J. S., Jaffe, M. B., Paulus, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Capnography, Clinical aspects. , (2004).</li><li>Kupnik, D., Skok, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capnometry+in+the+prehospital+setting:+are+we+using+its+potential.">Capnometry in the prehospital setting: are we using its potential.</a> Emerg Med J. 24, 614-617 (2007).</li><li>Delorio, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Continuous+end-tidal+carbon+dioxide+monitoring+for+confirmation+of+endotracheal+tube+placement+is+neither+widely+available+nor+consistently+applied+by+emergency+physicians.">Continuous end-tidal carbon dioxide monitoring for confirmation of endotracheal tube placement is neither widely available nor consistently applied by emergency physicians.</a> Emerg Med J. 22, 490-493 (2005).</li><li>Burton, J. H., Harrah, J. D., Germann, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Does+end-tidal+carbon+dioxide+monitoring+detect+respiratory+events+prior+to+current+sedation+monitoring+practices?.">Does end-tidal carbon dioxide monitoring detect respiratory events prior to current sedation monitoring practices?.</a> Acad Emerg Med. 13, 500-504 (2006).</li><li>Fletcher, R., Jonson, B., Cumming, G., Brew, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+concept+of+deadspace+with+special+reference+to+the+single+breath+test+for+carbon+dioxide.">The concept of deadspace with special reference to the single breath test for carbon dioxide.</a> Br J Anaesth. 53, 77-78 (1981).</li></ol>

No conflicts of interest declared.

Importance of CO2 for the Organism
Before exploring expired CO2 monitoring, it is essential to put into perspective the general role played by CO2 in the human body. Produced at a rate of approximately 200 ml per minute, CO2 is not just a wasted by-product of cellular metabolism. If our medullar chemoreceptors have the role of maintaining the arterial CO2 partial pressure (PaCO2) at 40mmHg, it is because CO2 has other functions in the organi...

expired co2 measurement in intubated or spontaneously breathing patients from the emergency department

Carbon dioxide (CO2) along with oxygen (O2) share the role of being the most important gases in the human body. The measuring of expired CO2 at the mouth has solicited growing clinical interest among physicians in the emergency department for various indications: (1) surveillance et monitoring of the intubated patient; (2) verification of the correct positioning of an endotracheal tube; (3) monitoring of a patient in cardiac arrest; (4) achieving normocapnia in intubated head trauma patients; (5) monitoring ventilation during procedural sedation. The video allows physicians to familiarize themselves with the use of capnography and the text offers a review of the theory and principals involved. In particular, the importance of CO2 for the organism, the relevance of measuring expired CO2, the differences between arterial and expired CO2, the material used in capnography with their artifacts and traps, will be reviewed. Since the main reluctance in the use of expired CO2 measurement is due to lack of correct knowledge concerning the physiopathology of CO2 by the physician, we hope that this explanation and the video sequences accompanying will help resolve this limitation.

Watch this Scientific Journal Video about Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department at JoVE.com

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department

This video describes how to perform CO2 measurement in intubated as well as spontaneously breathing patients. The main clinical indications refer to emergency situations: (1) verifying adequate positioning of an endotracheal tube; (2) achieving normocapnia in trauma patients; (3) monitoring ventilation in the case of procedural sedation.

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department

Carbon dioxide (CO2) along with oxygen (O2) share the role of being the most important gases in the human body. The measuring of expired CO2 at the mouth ...

expired-co2-measurement-intubated-or-spontaneously-breathing-patients

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16.1K Views.  Universit Catholique de Louvain Cliniques Universitaires Saint-Luc. This video describes how to perform CO2 measurement in intubated as well as spontaneously breathing patients. The main clinical indications refer to emergency situations: (1) verifying adequate positioning of an endotracheal tube; (2) achieving normocapnia in trauma patients; (3) monitoring ventilation in the case of procedural sedation.

Video: Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department

Isolation and Excision of Murine Aorta; A Versatile Technique in the Study of Cardiovascular Disease

Cardiovascular disease is a broad term describing disease of the heart and/or blood vessels. The main blood vessel supplying the body with oxygenated blood is the aorta. The aorta may become affected in diseases such as atherosclerosis and aneurysm. Researchers investigating these diseases would benefit from direct observation of the aorta to characterize disease progression as well as to evaluate efficacy of potential therapeutics. The goal of this protocol is to describe proper isolation and excision of the aorta to aid investigators researching cardiovascular disease. Isolation and excision of the aorta allows investigators to look at gross morphometric changes as wells as allowing them to preserve and stain the tissue to look at histologic changes if desired. The aorta may be used for molecular studies to evaluate protein and gene expression to discover targets of interest and mechanisms of action. This technique is superior to imaging modalities as they have inherent limitations in technology and cost. Additionally, primary isolated cells from a freshly isolated and excised aorta can allowing researchers to perform further in situ and in vitro assays. The isolation and excision of the aorta has the limitation of having to sacrifice the animal however, in this case the benefits outweigh the harm as it is the most versatile technique in the study of aortic disease.

Pathology of the aorta can lead to severe morbidity and mortality, therefore research of disease progression and potential therapies is warranted. Here, we present a protocol to isolate and excise the murine aorta to aid researchers in their investigation of cardiovascular disease.

Cardiovascular disease is a broad term describing disease of the heart and/or blood vessels. The main blood vessel supplying the body with oxygenated ...

Scleral Cross-linking Using Riboflavin and Ultraviolet-A Radiation for Prevention of Axial Myopia in a Rabbit Model

Myopic individuals, especially those with severe myopia, are at higher-than-normal risk of cataract, glaucoma, retinal detachment and chorioretinal abnormalities. In addition, pathological myopia is a common irreversible cause of visual impairment and blindness1-3. Our study demonstrates the effect of scleral crosslinking using riboflavin and ultraviolet-A radiation on the development of axial myopia in a rabbit model. The axial length of the eyeball was measured by A-scan ultrasound in New Zealand white rabbits aged 13 days (male and female). The eye then underwent 360&#176; conjunctival peritomy with scleral crosslinking, followed by tarsorrhaphy. Axial elongation was induced in 13 day-old New Zealand rabbits by suturing their right eye eyelids (tarsorrhaphy). The eyes were divided into quadrants, and every quadrant had two scleral irradiation zones, each with an area of 0.2 cm&#178; and a radius of 4 mm. Crosslinking was performed by dropping 0.1% dextran-free riboflavin-5-phosphate onto the irradiation zones 20 sec before ultraviolet-A irradiation and every 20 sec during the 200 sec irradiation time. UVA radiation (370 nm) was applied perpendicular to the sclera at 57 mW/cm&#178; (total UVA light dose, 57 J/cm&#178;). Tarsorrhaphies were removed on day 55, followed by repeated axial length measurements. This study demonstrates that scleral crosslinking with riboflavin and ultraviolet-A radiation effectively prevents occlusion-induced axial elongation in a rabbit model.

We demonstrate the effect of scleral crosslinking with riboflavin and UVA on an axial elongation rabbit eye. Axial elongation was induced in 13 day-old New Zealand rabbits (male and female) by suturing their right eye eyelids (tarsorrhaphy).

Myopic individuals, especially those with severe myopia, are at higher-than-normal risk of cataract, glaucoma, retinal detachment and chorioretinal ...

Setting Up a Stroke Team Algorithm and Conducting Simulation-based Training in the Emergency Department - A Practical Guide

Time is of the essence when caring for an acute stroke patient. The ultimate goal is to restore blood flow to the ischemic brain. This can be&#160;achieved by either&#160;thrombolysis with recombinant tissue-plasminogen activator (rt-PA), the standard therapy for stroke patients who present within the first hours of symptom onset without contraindications, or by an endovascular approach, if a proximal brain vessel occlusion is detected. As the efficacy of both therapies declines over time, every minute saved along the way will improve the patient&#39;s outcome.
This critical situation requires thorough work and precise communication with the patient, the family and colleagues from different professions to acquire all relevant information and reach the right decision while carefully monitoring the patient. This is a high fidelity situation. In nonmedical high-fidelity environments such as aviation, Crew Resource Management (CRM) is used to enhance safety and team efficiency.
This guide shows how a Stroke Team algorithm, which is transferable to other hospital settings, was established and how regular simulation-based trainings were performed. It requires determination and endurance to maintain these time-consuming simulation trainings on a regular basis over the course of time. However, the resulting improvement of team spirit and excellent door-to-needle times will benefit both the patients and the work environment in any hospital.
A dedicated Stroke Team of 7 persons who are notified 24/7 by a collective call via speed dial and run a binding algorithm that takes approximately 20 min, was established. To train everybody involved in this algorithm, a simulation-based team training for all new Stroke Team members was conceived and conducted at monthly intervals. This led to a relevant and sustained reduction of the mean door-to-needle time to 25 min, and enhanced the feeling of stroke readiness especially in junior doctors and nurses.

Every min counts in acute stroke care. This guide shows how to establish a Stroke Team algorithm and enhance its performance with regular simulation training. The principles of Crew Resource Management (CRM) facilitate a straight workflow, reduce door-to-needle times and increase staff satisfaction.

Time is of the essence when caring for an acute stroke patient. The ultimate goal is to restore blood flow to the ischemic brain. This can ...

Emergency Undocking in Robotic Surgery: A Simulation Curriculum

The following is a training platform to allow robotic surgeons to develop the skills necessary to lead an interprofessional team in emergency undocking of a robotic system. In traditional robotic training for surgeons, a brief web based overview of performing an emergency undocking is provided during initial introductory training to the robotics system. During such a process, there is no training in delineation of interdisciplinary roles for operating room (OR) personnel. The training presented here uses formative simulation and debriefing followed by a lecture. For the simulation, a modified gynecologic simulator is draped in a steep trendelenburg position consistent with most gynecologic laparoscopic surgery. The training torso is modified using tubing hooked to pressure bags of red food colored IV fluid used to simulate a catastrophic vessel injury on demand. Positioned throughout the operating room setting is an interprofessional team consisting of embedded standardized persons (ESPs) to fulfill the roles of a circulating nurse, scrub nurse, anesthesiologist, and bedside assist surgeon. Robotic surgeons are presented a case scenario necessitating emergency undocking, and given control of the robotic instruments. The scenario is terminated following either successful completion of an emergency undock, or at five minutes due to the emergent nature of the case. A debriefing session with hands on training of the steps to emergency undocking, necessary equipment, troubleshooting techniques, and operating room personnel roles follows the simulation. The learners are presented with a short lecture reemphasizing the material presented in the debriefing for their own self-study. This training results in improved time accessing the patient, improved knowledge, confidence, and completion of critical actions, and can be replicated in most institutions. All robotic surgeons should be able to demonstrate competence in this crucial intervention. A limitation of the curriculum is ability to access the in-situ environment for training purposes.

This training platform is designed to allow robotic surgeons to develop the skills necessary to lead an interprofessional team in emergency undocking of the robotic system. Training includes the utilization of the technology and equipment to perform an emergency undocking, as well as delineation of roles for such a scenario.

The following is a training platform to allow robotic surgeons to develop the skills necessary to lead an interprofessional team in emergency undocking of ...

Setup and Execution Of the Blindfolded Code Training Exercise

Miscommunication is the most common cause of preventable patient harm in medicine. Currently, there is limited knowledge of innovative techniques to improve resident physician communication and leadership strategies in high-acuity situations. The blindfolded code training exercise removes visual stimuli from the team leader, forcing the team leader to effectively utilize closed-loop communication. The simple act of blindfolding the team leader creates a learning environment where the leader must utilize a conceptual framework and critical thinking strategies to organize the team and manage the resuscitation. An advantage to this teaching technique is that it does not require any special simulation equipment, making it a low-cost approach. The blindfolded code training exercise can be applied to the management of any critically ill patient where the primary objective is to focus on developing communication skills in acute resuscitations. The purpose of the description of the blindfolded code training exercise is to provide guidance on how to perform this innovative teaching technique to force effective closed-loop communication.

The blindfolded code training exercise, which blindfolds the team leader in a code resuscitation simulation, is an advanced teaching technique to improve closed-loop communication, organizational skills, and critical thinking.&#160;

Miscommunication is the most common cause of preventable patient harm in medicine. Currently, there is limited knowledge of innovative techniques to ...

CO2-Lasertonsillotomy Under Local Anesthesia in Adults

Tonsil-related complaints are very common among the adult population. Tonsillectomy under general anesthesia is currently the most performed surgical treatment in adults for such complaints. Unfortunately, tonsillectomy is an invasive treatment associated with a high complication rate and a long recovery time. Complications and a long recovery time are mostly related to removing the vascular and densely innervated capsule of the tonsils. Recently, CO2-lasertonsillotomy under local anesthesia has been demonstrated to be a viable alternative treatment for tonsil-related disease with a significantly shorter and less painful recovery period. The milder side-effect profile of CO2-lasertonsillotomy is likely related to leaving the tonsil capsule intact. The aim of the current report is to present a concise protocol detailing the execution of CO2-lasertonsillotomy under local anesthesia. This intervention has been performed successfully in our hospital in more than 1,000 patients and has been found to be safe and to be associated with a steep learning curve.

CO2-Lasertonsillotomy Under Local Anesthesia in Adults

CO2-lasertonsillotomy under local anesthesia is an interesting alternative treatment method for tonsillectomy under general anesthesia for tonsil-related complaints in adults. This report presents a step-by-step protocol detailing the execution of CO2-lasertonsillotomy under local anesthesia.

Tonsil-related complaints are very common among the adult population. Tonsillectomy under general anesthesia is currently the most performed surgical ...

Cooling or Warming the Esophagus to Reduce Esophageal Injury During Left Atrial Ablation in the Treatment of Atrial Fibrillation

Ablation of the left atrium using either radiofrequency (RF) or cryothermal energy is an effective treatment for atrial fibrillation (AF) and is the most frequent type of cardiac ablation procedure performed. Although generally safe, collateral injury to surrounding structures, particularly the esophagus, remains a concern. Cooling or warming the esophagus to counteract the heat from RF ablation, or the cold from cryoablation, is a method that is used to reduce thermal esophageal injury, and there are increasing data to support this approach. This protocol describes the use of a commercially available esophageal temperature management device to cool or warm the esophagus to reduce esophageal injury during left atrial ablation. The temperature management device is powered by standard water-blanket heat exchangers, and is shaped like a standard orogastric tube placed for gastric suctioning and decompression. Water circulates through the device in a closed-loop circuit, transferring heat across the silicone walls of the device, through the esophageal wall. Placement of the device is analogous to the placement of a typical orogastric tube, and temperature is adjusted via the external heat-exchanger console.

The goal of this protocol is to describe the use of esophageal temperature modulation to counteract esophageal thermal injury from left atrial ablation for the treatment of atrial fibrillation.

Ablation of the left atrium using either radiofrequency (RF) or cryothermal energy is an effective treatment for atrial fibrillation (AF) and is the most ...

Real-Time Monitoring of Neurocritical Patients with Diffuse Optical Spectroscopies

Neurophysiological monitoring is an important goal in the treatment of neurocritical patients, as it may prevent secondary damage and directly impact morbidity and mortality rates. However, there is currently a lack of suitable non-invasive, real-time technologies for continuous monitoring of cerebral physiology at the bedside. Diffuse optical techniques have been proposed as a potential tool for bedside measurements of cerebral blood flow and cerebral oxygenation in case of neurocritical patients. Diffuse optical spectroscopies have been previously explored to monitor patients in several clinical scenarios ranging from neonatal monitoring to cerebrovascular interventions in adults. However, the feasibility of the technique to aid clinicians by providing real-time information at the bedside remains largely unaddressed. Here, we report the translation of a diffuse optical system for continuous real-time monitoring of cerebral blood flow, cerebral oxygenation, and cerebral oxygen metabolism during intensive care. The real-time feature of the instrument could enable treatment strategies based on patient-specific cerebral physiology rather than relying on surrogate metrics, such as arterial blood pressure. By providing real-time information on the cerebral circulation at different time scales with relatively cheap and portable instrumentation, this approach may be especially useful in low-budget hospitals, in remote areas and for&#160;monitoring in open fields (e.g., defense and sports).

Presented here is a protocol for non-invasively monitoring cerebral hemodynamics of neurocritical patients in real-time and at the bedside using diffuse optics. Specifically, the proposed protocol uses a hybrid diffuse optical systems to detect and display real-time information on cerebral oxygenation, cerebral blood flow and cerebral metabolism.

Neurophysiological monitoring is an important goal in the treatment of neurocritical patients, as it may prevent secondary damage and directly impact ...

Measurement of Tissue Oxygenation Using Near-Infrared Spectroscopy in Patients Undergoing Hemodialysis

Near-infrared spectroscopy (NIRS) has recently been applied as a tool to measure regional oxygen saturation (rSO2), a marker of tissue oxygenation, in clinical settings including cardiovascular and brain surgery, neonatal monitoring and prehospital medicine. The NIRS monitoring devices are real-time and noninvasive, and have mainly been used for evaluating cerebral oxygenation in critically ill patients during an operation or intensive care. Thus far, the use of NIRS monitoring in patients with chronic kidney disease (CKD) including hemodialysis (HD) has been limited; therefore, we investigated rSO2 values in some organs during HD. We monitored rSO2 values using a NIRS device transmitting near-infrared light at 2 wavelengths of attachment. The HD patients were placed in a supine position, with rSO2 measurement sensors attached to the foreheads, the right hypochondrium and the lower legs to evaluate rSO2 in the brain, liver and lower leg muscles, respectively. NIRS monitoring could be a new approach to clarify changes in organ oxygenation during HD or factors affecting tissue oxygenation in CKD patients. This article describes a protocol to measure tissue oxygenation represented by rSO2 as applied in HD patients.

We present a protocol to measure regional oxygen saturation (rSO2) in hemodialysis (HD) patients by using a near-infrared spectroscopy monitor. The rSO2 value is an index of tissue oxygenation. This noninvasive and real-time monitoring could be useful for confirming changes in organ oxygenation during HD.

Near-infrared spectroscopy (NIRS) has recently been applied as a tool to measure regional oxygen saturation (rSO2), a marker of tissue oxygenation, in ...

A Novel Inhalation Mask System to Deliver High Concentrations of Nitric Oxide Gas in Spontaneously Breathing Subjects

Nitric Oxide (NO) is administered as gas for inhalation to induce selective pulmonary vasodilation. It is a safe therapy, with few potential risks even if administered at high concentration. Inhaled NO gas is routinely used to increase systemic oxygenation in different disease conditions. The administration of high concentrations of NO also exerts a virucidal effect in vitro. Owing to its favorable pharmacodynamic and safety profiles, the familiarity in its use by critical care providers, and the potential for a direct virucidal effect, NO is clinically used in patients with coronavirus disease-2019 (COVID-19). Nevertheless, no device is currently available to easily administer inhaled NO at concentrations higher than 80 parts per million (ppm) at various inspired oxygen fractions, without the need for dedicated, heavy, and costly equipment. The development of a reliable, safe, inexpensive, lightweight, and ventilator-free solution is crucial, particularly for the early treatment of non-intubated patients outside of the intensive care unit (ICU) and in a limited-resource scenario. To overcome such a barrier, a simple system for the non-invasive NO gas administration up to 250 ppm was developed using standard consumables and a scavenging chamber. The method has been proven safe and reliable in delivering a specified NO concentration while limiting nitrogen dioxide levels. This paper aims to provide clinicians and researchers with the necessary information on how to assemble or adapt such a system for research purposes or clinical use in COVID-19 or other diseases in which NO administration might be beneficial.

This simple and highly adaptable system device for the inhalation of high-concentration nitric oxide (NO) gas does not require mechanical ventilators, positive pressure, or high gas flows. Standard medical consumables and a snug-fitting mask are used to safely deliver NO gas to spontaneously breathing subjects.

Nitric Oxide (NO) is administered as gas for inhalation to induce selective pulmonary vasodilation. It is a safe therapy, with few potential risks even if ...