This study was supported in part by the grants from the Ministry of Science and Technology, Taiwan (MOST 103-2511-S-002-007). The authors would like to thank Dr. Chih-Hsien Wu and Mr. Jen-Chih Sung for helping the preparation of the photographs and film.

This procedure was approved by the Institutional Review Board of the National Taiwan University Hospital and registered at ClinicalTrials.gov (NCT02952768).
1. Instrumentation
<ol>
	<li>Use a US machine equipped with a curvilinear 2&#8211;5 MHz probe. A portable US is more suitable for CPR.</li>
</ol>
2. Personnel and their roles in the resuscitation team
<ol>
	<li>Ideally, a resuscitation team should be comprised of six members: 1) a leader; 2) a member for airway management (A) and ventilation (B); 3) one for chest compressions (C); 4) one for defibrillation (D); 5) one for intravenous (IV) catheterization and medication; and 6) a recorder.</li>
	<li>If the personnel is limited, have the roles overlap. When US is integrated into the CPR process, the sonographer should be an independent member of the team who is well trained and experienced in resuscitation US and can intervene and interpret the US images in a timely manner without interrupting or delaying resuscitation efforts. However, the leader can also be the sonographer. He or she can use US to search for any potentially reversible causes of resuscitation failure as early as possible while leading the whole CPR process.</li>
</ol>
3. Cardiopulmonary resuscitation process
<ol>
	<li>Perform all resuscitation procedures according to the ALS guidelines6.</li>
	<li>When US is integrated into the CPR process, strict control to minimize interruption of the chest compressions is the highest priority. Restrict the hands-off interval for pulse checks/rhythm analysis and simultaneous US evaluation to no longer than 10 s.
	<ol>
		<li>Use a timer with preset alarms to remind the sonographer of the time intervals. Set the alarm for every 2 min of CPR and 10 s for pulse checks.</li>
	</ol>
	</li>
</ol>
4. US-CAB protocol
<ol>
	<li>US-C: Use cardiac US (US-C) at the start of CPR and at the end of the first five cycles of chest compressions.
	<ol>
		<li>Use the subxiphoid four-chamber view (Figure 1A) to check pericardial effusion, the size of the right and left ventricles, and sonographic cardiac activity.</li>
		<li>Turn the probe 90&#176; (parallel to the long axis of the patient) to measure the diameter of the IVC (Figure 1B).</li>
	</ol>
	</li>
	<li>US-A: Use US-A to check the endotracheal tube location after intubation.
	<ol>
		<li>Place the probe transversely at the suprasternal notch (Figure 1C).</li>
		<li>Note the one air-mucosal interface with one comet-tail artifact (single tract sign) for tracheal intubation.</li>
		<li>Move the probe to the lateral side of the neck to reconfirm the single tract sign.</li>
		<li>Perform reintubation if there are two air-mucosal interfaces with two comet-tail artifacts (double tract sign)12.</li>
	</ol>
	</li>
	<li>US-B: Use US-B to check proper ventilation.
	<ol>
		<li>Put the probe on either side of the chest at the 4th&#8211;5th intercostal spaces over the midaxillary line (Figure 1D).</li>
		<li>Detect lung sliding to evaluate pulmonary ventilation11,13.</li>
		<li>If lung sliding is absent on one side, adjust the depth of the endotracheal tube until bilateral lung sliding is noticed.</li>
	</ol>
	</li>
	<li>US-C: Repeat US-C every 2 min when chest compression is stopped for pulse checks.</li>
	<li>Repeat US-AB after transportation and bed transfer of the patient.</li>
</ol>
5. Settings and approach during CPR
<ol>
	<li>Keep the US machine ready in the resuscitation room of the emergency department. In cases of in-hospital cardiac arrest, a portable US device can be brought to the scene immediately, and turned on instantly.</li>
	<li>Because a lot of resuscitation procedures are performed around the head, neck, and chest of the patient (e.g., chest compressions, defibrillation, intubation, ventilation, etc.), place the US machine in the caudal area of the patient (Figure 2). For example, it should be located over the patient&#8217;s right side for a right-handed sonographer and vice versa. This way the sonographer can get the probe ready and immediately assess the patient&#8217;s condition.</li>
</ol>
6. Image acquisition and recording
<ol>
	<li>Have the US images interpreted by the sonographer and print or store important images for medical records and further discussion with the resuscitation team.</li>
	<li>Ideally, store the US images in the hard disk of the US machine for regular (e.g., monthly) review, either for quality assurance or teaching purposes. Video recording is even better, as it not only provides important information that is less well characterized by still photos but also offers materials for training or subsequent analysis.</li>
</ol>
7. Data interpretation and analysis
<ol>
	<li>Have the sonographer interpret the US images during CPR on-site to help with clinical judgement and decision making. A sonographer, after structured training and continued practice, can perform sonographic evaluation and interpret the data in real CPR scenarios. The interpretation and discussion of the data can also be done by all resuscitation team members during debriefing immediately after the post-CPR phase. The discussion focuses not only on US diagnosis, but on the therapeutic interventions and impact on CPR outcomes following the US examination.</li>
	<li>For research purposes, also have interpretation done afterwards by blinded researchers.</li>
</ol>

<ol>
	<li>Soar, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=European+Resuscitation+Council+Guidelines+for+Resuscitation+2015:+Section+3.+Adult+advanced+life+support.">European Resuscitation Council Guidelines for Resuscitation 2015: Section 3. Adult advanced life support.</a> Resuscitation. 95, 100-147 (2015).</li><li>Takeda, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+assessment+of+three+methods+to+verify+tracheal+tube+placement+in+the+emergency+setting.">The assessment of three methods to verify tracheal tube placement in the emergency setting.</a> Resuscitation. 56 (2), 153-157 (2003).</li><li>Levine, R., Wayne, M., Miller, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=End-tidal+carbon+dioxide+and+outcome+of+out-of-hospital+cardiac+arrest.">End-tidal carbon dioxide and outcome of out-of-hospital cardiac arrest.</a> New England Journal of Medicine. 337, 301-306 (1997).</li><li>Moule, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Checking+the+carotid+pulse:+diagnostic+accuracy+in+students+of+the+healthcare+professions.">Checking the carotid pulse: diagnostic accuracy in students of the healthcare professions.</a> Resuscitation. 44 (3), 195-201 (2000).</li><li>Sitzwohl, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endobronchial+intubation+detected+by+insertion+depth+of+endotracheal+tube,+bilateral+auscultation,+or+observation+of+chest+movements:+randomised+trial.">Endobronchial intubation detected by insertion depth of endotracheal tube, bilateral auscultation, or observation of chest movements: randomised trial.</a> British Medical Journal. 341, 5943 (2010).</li><li>Monsieurs, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=European+Resuscitation+Council+Guidelines+for+Resuscitation+2015:+Section+1.+Executive+summary.">European Resuscitation Council Guidelines for Resuscitation 2015: Section 1. Executive summary.</a> Resuscitation. 95, 1-80 (2015).</li><li>Breitkreutz, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Focused+echocardiographic+evaluation+in+life+support+and+peri-resuscitation+of+emergency+patients:+a+prospective+trial.">Focused echocardiographic evaluation in life support and peri-resuscitation of emergency patients: a prospective trial.</a> Resuscitation. 81 (11), 1527-1533 (2010).</li><li>Hernandez, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=C.A.U.S.E.:+Cardiac+arrest+ultra-sound+exam--a+better+approach+to+managing+patients+in+primary+non-arrhythmogenic+cardiac+arrest.">C.A.U.S.E.: Cardiac arrest ultra-sound exam--a better approach to managing patients in primary non-arrhythmogenic cardiac arrest.</a> Resuscitation. 76 (2), 198-206 (2008).</li><li>Perera, P., Mailhot, T., Riley, D., Mandavia, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+RUSH+exam:+Rapid+Ultrasound+in+SHock+in+the+evaluation+of+the+critically+lll.">The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically lll.</a> Emergency Medicine Clinics of North America. 28 (1), 29-56 (2010).</li><li>Blyth, L., Atkinson, P., Gadd, K., Lang, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bedside+focused+echocardiography+as+predictor+of+survival+in+cardiac+arrest+patients:+a+systematic+review.">Bedside focused echocardiography as predictor of survival in cardiac arrest patients: a systematic review.</a> Academic Emergency Medicine. 19, 1119-1126 (2012).</li><li>Lien, W. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=US-CAB+protocol+for+ultrasonographic+evaluation+during+cardiopulmonary+resuscitation:+validation+and+potential+impact.">US-CAB protocol for ultrasonographic evaluation during cardiopulmonary resuscitation: validation and potential impact.</a> Resuscitation. 127, 125-131 (2018).</li><li>Chou, H. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-time+tracheal+ultrasonography+for+confirmation+of+endotracheal+tube+placement+during+cardiopulmonary+resuscitation.">Real-time tracheal ultrasonography for confirmation of endotracheal tube placement during cardiopulmonary resuscitation.</a> Resuscitation. 84 (12), 1708-1712 (2013).</li><li>Sim, S. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasonographic+lung+sliding+sign+in+confirming+proper+endotracheal+intubation+during+emergency+intubation.">Ultrasonographic lung sliding sign in confirming proper endotracheal intubation during emergency intubation.</a> Resuscitation. 83 (3), 307-312 (2012).</li><li>Lien, W. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+US-CAB+protocol+for+ultrasonographic+evaluation+during+cardiopulmonary+resuscitation.">A novel US-CAB protocol for ultrasonographic evaluation during cardiopulmonary resuscitation.</a> Resuscitation. 115, 1-2 (2017).</li><li>Roelandt, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound+stethoscopy.">Ultrasound stethoscopy.</a> European Journal of Internal Medicine. 15, 337-347 (2004).</li><li>Lien, W. C., Chang, W. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Potential+Pitfall+of+Tracheal+Ultrasound+for+the+Confirmation+of+Endotracheal+Intubations.">A Potential Pitfall of Tracheal Ultrasound for the Confirmation of Endotracheal Intubations.</a> Journal of Ultrasound in Medicine. , (2019).</li><li>Huis In't Veld, M. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound+use+during+cardiopulmonary+resuscitation+is+associated+with+delays+in+chest+compressions.">Ultrasound use during cardiopulmonary resuscitation is associated with delays in chest compressions.</a> Resuscitation. 119, 95-98 (2017).</li><li>Clattenburg, E. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Point-of-care+ultrasound+use+in+patients+with+cardiac+arrest+is+associated+prolonged+cardiopulmonary+resuscitation+pauses:+A+prospective+cohort+study.">Point-of-care ultrasound use in patients with cardiac arrest is associated prolonged cardiopulmonary resuscitation pauses: A prospective cohort study.</a> Resuscitation. 122 (1), 65-68 (2018).</li><li>Lien, W. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Data+on+evaluation+of+proficiency+for+the+US-CAB+curriculum.">Data on evaluation of proficiency for the US-CAB curriculum.</a> Data in Brief. 16 (17), 965-968 (2017).</li><li>Lien, W. C., Chang, W. T., Ma, M. H., Chen, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasonography+during+CPR:+Hands-off+or+hands-on.">Ultrasonography during CPR: Hands-off or hands-on.</a> Resuscitation. 125, 8-10 (2018).</li></ol>

The authors have nothing to disclose.

US is a noninvasive, real-time, and readily available imaging modality in emergency and critical care settings. Application of US during CPR plays an important role in diagnosis, guidance of therapeutic intervention, or monitoring15. While many US protocols have been introduced for use with CPR, the US-CAB protocol complies with the sequence of advanced life support (ALS). It integrates important US techniques to detect possibly reversible causes of any issues, and to evaluate the C-A-B status dur...

Effective cardiopulmonary resuscitation (CPR) for cardiac arrest is key to successful revival of a patient. Circulation (C), airway (A), and breathing (B) are the three crucial components in either basic (BLS) or advanced life support (ALS). The evaluation of the C-A-B status during CPR basically relies on pulse checks, auscultation, and capnography1. In true clinical conditions, however, CPR is often complex and chaotic, and these methods may have limitations2,3. For example, the accuracy of pulse checks is often suboptimal even when performed by healthcare providers4. More than half of one lung intubations might be misdirected if guided by auscultation alone5. Even wave capnography can be affected by factors such as low cardiac output, low pulmonary flow, and use of epinephrine during CPR2. Therefore, more effective, accurate evaluation of the C-A-B status is mandatory.
When trying to search for the etiology of cardiac arrest or any potentially reversible factors during CPR, medical history and physical examination are often insufficient. The detection of reversible causes, such as the 5Hs (i.e., hypoxia, hypovolemia, hyperkalemia/hypokalemia, acidosis, and hypothermia) and the 5Ts (i.e., cardiac tamponade, tension pneumothorax, pulmonary thromboembolism, coronary thrombosis, and toxins or tablets), often requires advanced examinations.
Ultrasound (US) is a useful imaging modality in emergency and critical care settings. The European Resuscitation Council (ERC) Guidelines suggest that US can be an integral part of resuscitation6. US can readily identify critical but potentially reversible factors that negatively affect CPR, such as cardiac tamponade, pulmonary thromboembolism, and hypovolemia7,8,9. US also helps rule out pneumothorax and acute coronary syndrome. Moreover, US confers prognostic implications even when CPR is being performed. The presence of sonographic cardiac activity during CPR has been reported to confer higher chances of ROSC, survival, and hospital discharge10,11. In addition to sonographic evaluation of the heart and circulation status, tracheal US is employed for confirmation of proper endotracheal intubation12, while lung US is applied to confirm proper bilateral pulmonary ventilation13.
While high-quality CPR with minimal interruptions to the compressions is the most important factor for resuscitation, it is important to understand how to seamlessly integrate US into the process of resuscitation without interfering with CPR. We therefore developed a novel, ALS-compliant US-CAB protocol for use during CPR14. This paper presents a detailed description of the settings, personnel, and instruments necessary for better integration of the US protocol into the regular CPR process that first-line physicians can easily incorporate and implement into their practice.

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			<td class="xl65" height="21" style="height:15.75pt;width:162pt" width="216">Ultrasound</td>
			<td class="xl65" style="width:140pt" width="186">Cannon, Japan</td>
			<td class="xl65" style="width:89pt" width="119">SSA-550A</td>
			<td class="xl66" style="width:125pt" width="167">nil</td>
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ultrasonographic assessment during cardiopulmonary resuscitation

The US-CAB (Ultrasound, Circulation/Airway/Breathing) protocol integrates several sonographic techniques into a structured assessment of the circulation, airway, and breathing status of a patient during cardiopulmonary resuscitation (CPR) in an advanced life support-compliant manner. US-C provides a subxiphoid view of the heart, to look for potentially reversible causes of disease, such as pericardial effusion, pulmonary embolism, hypovolemia, and acute coronary thrombosis. Sonographic cardiac activity during CPR not only helps differentiate pseudo-pulseless electrical activity (PEA) from true PEA but also represents a higher chance of the return of spontaneous circulation (ROSC) and survival. Evaluation of the inferior vena cava (IVC) shows the fluid status of the patient and indicates the best methods to use for fluid resuscitation. If aortic dissection is suspected, a subxiphoid view of the aorta is suggested for identifying an intimal flap. Once intubation is done, tracheal ultrasound (US-A) at the suprasternal notch helps differentiate endotracheal intubation (one air-mucosal interface with one comet-tail) from esophageal intubation (double tract sign). Immediately following US-A, bilateral lung US (US-B) should be done to confirm proper bilateral ventilation using the lung sliding sign. In addition, US-C can be serially followed to see the dynamic changes in the cardiac chambers and IVC, or any cardiac contraction suggestive of ROSC. US-B can also detect coexisting lung or pleural pathologies without interfering with the performance of CPR. The main concern when implementing this method is maintaining high-quality CPR without delays in chest compressions when performing US-CAB. Rigorous training and continued practice are key to minimize any interruptions during resuscitation.

US-C with subxiphoid evaluation of the heart displays a cardiac four-chamber view as shown in Figure 3A. At this point, detection of any of the three typical patterns suggestive of specific etiologies or reversible factors is possible.
Identify the presence and characters of pericardial effusion: If pericardial effusion is present, notice if the right heart chambers (i.e., the right atrium or even the right ventricle) are compressed. If compression of the right at...

Watch this Scientific Journal Video about Ultrasonographic Assessment During Cardiopulmonary Resuscitation at JoVE.com

Ultrasonographic Assessment During Cardiopulmonary Resuscitation

Here, we present a US-CAB (Ultrasound, Circulation/Airway/Breathing) protocol for use during cardiopulmonary resuscitation (CPR). US-C evaluates the subxiphoid view of the heart and inferior vena cava. After intubation, tracheal US (US-A) and lung US (US-B) help confirm endotracheal intubation and proper ventilation.

The US-CAB (Ultrasound, Circulation/Airway/Breathing) protocol integrates several sonographic techniques into a structured assessment of the circulation, ...

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6.3K Views.  National Taiwan University Hospital and College of Medicine. Here, we present a US-CAB (Ultrasound, Circulation/Airway/Breathing) protocol for use during cardiopulmonary resuscitation (CPR). US-C evaluates the subxiphoid view of the heart and inferior vena cava. After intubation, tracheal US (US-A) and lung US (US-B) help confirm endotracheal intubation and proper ventilation.

Video: Ultrasonographic Assessment During Cardiopulmonary Resuscitation

Normothermic Cardiac Arrest and Cardiopulmonary Resuscitation: A Mouse Model of Ischemia-Reperfusion Injury

Acute Kidney Injury (AKI) is a common, highly lethal, complication of critical illness which has a high mortality1-4 and which is most 
frequently caused by whole-body hypoperfusion.5,6 Successful reproduction of whole-body hypoperfusion in rodent models has been fraught with 
difficulty.7-9,9,10 Models which employ focal ischemia have repeatedly demonstrated results which do not translate to the clinical setting, and larger 
animal models which allow for whole body hypoperfusion lack access to the full toolset of genetic manipulation possible in the mouse.11,12 However, in recent 
years a mouse model of cardiac arrest and cardiopulmonary resuscitation has emerged which can be adapted to model AKI.13 This model reliably reproduces 
physiologic, functional, anatomic, and histologic outcomes seen in clinical AKI, is rapidly repeatable, and offers all of the significant advantages of a murine surgical 
model, including access to genetic manipulative techniques, low cost relative to large animals, and ease of use. Our group has developed extensive experience 
with use of this model to assess a number of organ-specific outcomes in AKI.14,15

A powerful model for perioperative and critical care related acute kidney injury is presented. Using whole body hypoperfusion induced by cardiac arrest it is possible to nearly replicate the histologic and functional changes of clinical AKI.

Acute Kidney Injury (AKI) is a common, highly lethal, complication of critical illness which has a high mortality1-4 and which is most 
frequently caused ...

A Rat Model of Ventricular Fibrillation and Resuscitation by Conventional Closed-chest Technique

A rat model of electrically-induced ventricular fibrillation followed by cardiac resuscitation using a closed chest technique that incorporates the basic components of cardiopulmonary resuscitation in humans is herein described. The model was developed in 1988 and has been used in approximately 70 peer-reviewed publications examining a myriad of resuscitation aspects including its physiology and pathophysiology, determinants of resuscitability, pharmacologic interventions, and even the effects of cell therapies. The model featured in this presentation includes: (1) vascular catheterization to measure aortic and right atrial pressures, to measure cardiac output by thermodilution, and to electrically induce ventricular fibrillation; and (2) tracheal intubation for positive pressure ventilation with oxygen enriched gas and assessment of the end-tidal CO2. A typical sequence of intervention entails: (1) electrical induction of ventricular fibrillation, (2) chest compression using a mechanical piston device concomitantly with positive pressure ventilation delivering oxygen-enriched gas, (3) electrical shocks to terminate ventricular fibrillation and reestablish cardiac activity, (4) assessment of post-resuscitation hemodynamic and metabolic function, and (5) assessment of survival and recovery of organ function. A robust inventory of measurements is available that includes &#8211; but is not limited to &#8211; hemodynamic, metabolic, and tissue measurements. The model has been highly effective in developing new resuscitation concepts and examining novel therapeutic interventions before their testing in larger and translationally more relevant animal models of cardiac arrest and resuscitation.

This article describes a rat model of electrically-induced ventricular fibrillation and resuscitation by chest compression, ventilation, and delivery of electrical shocks that simulates an episode of sudden cardiac arrest and conventional cardiopulmonary resuscitation. The model enables gathering insights on the pathophysiology of cardiac arrest and exploration of new resuscitation strategies.

A rat model of electrically-induced ventricular fibrillation followed by cardiac resuscitation using a closed chest technique that incorporates the basic ...

Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise

Exercise is a stress to the pulmonary vasculature. With incremental exercise, the pulmonary diffusing capacity (DLCO) must increase to meet the increased oxygen demand; otherwise, a diffusion limitation may occur. The increase in DLCO with exercise is due to increased capillary blood volume (Vc) and membrane diffusing capacity (Dm). Vc and Dm increase secondary to the recruitment and distension of pulmonary capillaries, increasing the surface area for gas exchange and decreasing pulmonary vascular resistance, thereby attenuating the increase in pulmonary arterial pressure. At the same time, the recruitment of intrapulmonary arteriovenous anastomoses (IPAVA) during exercise may contribute to gas exchange impairment and/or prevent large increases in pulmonary artery pressure.
We describe two techniques to evaluate pulmonary diffusion and circulation at rest and during exercise. The first technique uses multiple-fraction of inspired oxygen (FIO2) DLCO breath holds to determine Vc and Dm at rest and during exercise. Additionally, echocardiography with intravenous agitated saline contrast is used to assess IPAVAs recruitment.
Representative data showed that the DLCO, Vc, and Dm increased with exercise intensity. Echocardiographic data showed no IPAVA recruitment at rest, while contrast bubbles were seen in the left ventricle with exercise, suggesting exercise-induced IPAVA recruitment.
The evaluation of pulmonary capillary blood volume, membrane diffusing capacity, and IPAVA recruitment using echocardiographic methods is useful to characterize the ability of the lung vasculature to adapt to the stress of exercise in health as well as in diseased groups, such as those with pulmonary arterial hypertension and chronic obstructive pulmonary disease.

To assess the pulmonary diffusion and vasculature responses to exercise, we describe the multiple-inspired oxygen diffusion capacity technique to determine capillary blood volume and membrane diffusing capacity, as well as agitated saline contrast echocardiography to assess the recruitment of intrapulmonary arteriovenous anastomoses.

Exercise is a stress to the pulmonary vasculature. With incremental exercise, the pulmonary diffusing capacity (DLCO) must increase to meet the increased ...

Cardiopulmonary Bypass in a Mouse Model: A Novel Approach

As prolonged cardiopulmonary bypass becomes more essential during cardiac interventions, an increasing clinical demand arises for procedure optimization and for minimizing organ damage resulting from prolonged extracorporal circulation. The goal of this paper was to demonstrate a fully functional and clinically relevant model of cardiopulmonary bypass in a mouse. We report on the device design, perfusion circuit optimization, and microsurgical techniques. This model is an acute model, which is not compatible with survival due to the need for multiple blood drawings. Because of the range of tools available for mice (e.g., markers, knockouts, etc.), this model will facilitate investigation into the molecular mechanisms of organ damage and the effect of cardiopulmonary bypass in relation to other comorbidities.

This paper describes how to perform cardiopulmonary bypass in mice. This novel model will facilitate the investigation of the molecular mechanisms involved in organ damage.

As prolonged cardiopulmonary bypass becomes more essential during cardiac interventions, an increasing clinical demand arises for procedure optimization ...

Microscopy Based Methods for the Assessment of Epithelial Cell Migration During In Vitro Wound Healing

Cell migration is a mandatory aspect for wound healing. Creating artificial wounds on research animal models often results in costly and complicated experimental procedures, while potentially lacking in precision. In vitro culture of epithelial cell lines provides a suitable platform for researching the cell migratory behavior in wound healing and the impact of treatments on these cells. The physiology of epithelial cells is often studied in non-confluent conditions; however, this approach may not resemble natural wound healing conditions. Disrupting the epithelium integrity by mechanical means generates a realistic model, but may impede the application of molecular techniques. Consequently, microscopy based techniques are optimal for studying epithelial cell migration in vitro. Here we detail two specific methods, the artificial wound scratch assay and the artificial migration front assay, that can obtain quantitative and qualitative data, respectively, on the migratory performance of epithelial cells.

Microscopy Based Methods for the Assessment of Epithelial Cell Migration During  In Vitro Wound Healing

This manuscript describes how incision-like lesions made on cultured epithelial cell monolayers conveniently model wound healing in vitro, allowing for imaging by confocal or laser scanning microscopy, and which can provide high-quality quantitative and qualitative data for studying both cell behavior and the mechanisms involved in migration.

Cell migration is a mandatory aspect for wound healing. Creating artificial wounds on research animal models often results in costly and complicated ...

The Perinatal Asphyxiated Lamb Model: A Model for Newborn Resuscitation

Birth asphyxia accounts for nearly one million deaths worldwide each year, and is one of the primary causes of early neonatal morbidity and mortality. Many aspects of the current neonatal resuscitation guidelines remain controversial given the difficulties in conducting randomized clinical trials owing to the infrequent and often unpredictable need for extensive resuscitation. Most studies on neonatal resuscitation stem from manikin models that fail to truly reflect physiologic changes or piglet models that have cleared their lung fluid and that have completed the transition from fetal to neonatal circulation. The present protocol provides a detailed step-by-step description on how to create a perinatal asphyxiated fetal lamb model. The proposed model has a transitioning circulation and fluid-filled lungs, which mimics human newborns following delivery, and is, therefore, an excellent animal model to study newborn physiology. An important limitation to lamb experiments is the higher associated cost.

Invasive instrumentation of the fetal lamb provides accurate physiologic measurements of the transitioning circulation in a model that closely mimics the newly born infant.

Birth asphyxia accounts for nearly one million deaths worldwide each year, and is one of the primary causes of early neonatal morbidity and mortality. ...

Providing Visual Biofeedback Using Brightness Mode Ultrasound During a Golf Swing

Using ultrasound biofeedback in conjunction with verbal cueing can increase muscle thickness more than verbal cueing alone and may augment traditional rehabilitation techniques in an athletic, physically active population. Brightness mode (B-mode) ultrasound can be applied using frame-by-frame analysis synchronized with video to understand muscle thickness changes during these dynamic tasks. Visual biofeedback with ultrasound has been established in static positions for the muscles of the lateral abdominal wall. However, by securing the transducer to the abdomen using an elastic belt and foam block, biofeedback can be applied during more specific tasks prevalent in lifetime sports, such as golf. To analyze muscle activity during a golf swing, muscle thickness changes can be compared. The thickness must increase throughout the task, indicating that the muscle is more active. This methodology allows clinicians to immediately replay ultrasound videos for patients as a visual tool to instruct proper activity of the muscles of interest. For example, ultrasound can be used to target the external and internal obliques, which play an important role in swinging a golf club or any other rotational sport or activity. This methodology aims to increase oblique muscle thickness during the golf swing. Additionally, the timing of muscle contraction can be targeted by instructing the patient to contract the abdominal muscles at specific time points, such as the beginning of the downswing, with the goal of improving muscle firing patterns during tasks.

Brightness mode ultrasound can be used to provide visual biofeedback of the muscles of the lateral abdominal wall during a golf swing. Post-swing visual and verbal instruction can increase the muscle activation and timing of the external and internal obliques.

Using ultrasound biofeedback in conjunction with verbal cueing can increase muscle thickness more than verbal cueing alone and may augment traditional ...

Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured between fascial borders at a given time point during an exercise. This selected time point produces a one-dimensional image resulting in real-time, live observation of anatomy. Ultrasound used during functional movement can be referred to as dynamic ultrasound; this is feasible and reliable with the use of a linear transducer, elastic belt, and foam block to secure consistent transducer placement. The lateral abdominal wall is commonly investigated using ultrasound due to the overlapping nature of the muscles. Surface electromyography (sEMG) can complement M-mode ultrasound imaging because it measures the electrical representation of muscle activation. There is minimal evidence using M-mode ultrasound and sEMG simultaneously during core exercise. Exercises that challenge the core musculature involve both isometric holds (e.g., side plank), as well as oscillatory extremity movements (e.g., dead bug). In this study, both instruments will be used simultaneously to measure core muscle function during exercise. Ultrasound measurements will be obtained using a linear transducer and ultrasound unit, and sEMG measurements will be acquired from a wireless sEMG system. To make comparisons between participants and exercises, normalization methods using static, exercise starting positions for both instruments will be used. An activation ratio will be used for ultrasound and calculated by dividing the contracted thickness (thickness during a time point of exercise) by the rested (starting position) thickness. Muscle thickness will be measured in centimeters from the superior inferior fascial border to inferior superior fascial border. These methods aim to offer an innovative and practical measurement of muscle function with M-mode ultrasound and sEMG during core endurance exercises.

This protocol uses motion mode ultrasound and surface electromyography simultaneously to measure muscle function of the core. Muscle thickness and activation of the local stabilizers (e.g., transverse abdominis, internal oblique) and global movers (e.g., external oblique) is achievable during specific time points of the side plank and dead bug exercises.

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured ...

Functional Assessment of the Donor Heart During Ex Situ Perfusion: Insights from Pressure-Volume Loops and Surface Echocardiography

Heart transplantation remains the gold standard treatment for advanced heart failure. However, the current critical organ shortage has resulted in the allocation of a growing number of donor hearts with extended criteria. These marginal grafts are associated with a high risk of primary graft failure and may benefit from ex situ perfusion before transplant. This technology allows for extended organ preservation using warm oxygenated blood perfusion with continuous metabolic monitoring. The only NESP device currently available for clinical practice perfuses the organ in an unloaded non-working state, which does not allow for functional assessment of the beating heart. We therefore developed an original platform of NESP in working mode conditions with adjustment of left ventricular preload and afterload. This protocol was applied in porcine hearts. Ex situ functional assessment of the heart was achieved with intracardiac conductance catheterization and surface echocardiography. Along with a description of the experimental protocol, we herein report the main results, as well as pearls and pitfalls associated with the acquisition of pressure-volume loops and myocardial power during NESP. Correlations between hemodynamic findings and ultrasound variables are of major interest, especially for further rehabilitation of donor hearts before transplantation. This protocol aims to improve the assessment of donor hearts to both increase the donor pool and reduce the incidence of primary graft failure.

Functional Assessment of the Donor Heart During Ex Situ Perfusion: Insights from Pressure-Volume Loops and Surface Echocardiography

A reliable noninvasive approach for functional assessment of the donor heart during normothermic ex situ heart perfusion (NESP) is lacking. We herein describe a protocol for ex situ assessment of myocardial performance using the epicardial echocardiography and conductance catheter method.

Heart transplantation remains the gold standard treatment for advanced heart failure. However, the current critical organ shortage has resulted in the ...

Extracorporeal Cardiopulmonary Resuscitation in Animal Model After Cardiac Arrest

Pediatric Animal Model of Extracorporeal Cardiopulmonary Resuscitation After Prolonged Circulatory Arrest

Congenital heart disease (CHD) is the most prevalent congenital malformation, with about one million births impacted worldwide per year. Comprehensive investigation of this disease requires appropriate and validated animal models. Piglets are commonly used for translational research due to their analogous anatomy and physiology. This work aimed to describe and validate a neonatal piglet model of cardiopulmonary bypass (CPB) with circulatory and cardiac arrest (CA) as a tool for studying severe brain damage and other complications of cardiac surgery. In addition to including a list of materials, this work provides a roadmap for other investigators to plan and execute this protocol. After experienced practitioners performed several trials, the representative results of the model demonstrated a 92% success rate, with failures attributed to small piglet size and variant vessel anatomy. Furthermore, the model allowed practitioners to select from a wide variety of experimental conditions, including varying times in CA, temperature alterations, and pharmacologic interventions. In summary, this method uses materials readily available in most hospital settings, is reliable and reproducible, and can be widely employed to enhance translational research in children undergoing heart surgery.

Author Spotlight: Simulating Pediatric Cardiac Surgery Using a Neonatal Piglet Model

This protocol describes a neonatal porcine model of cardiopulmonary bypass (CPB), with circulatory and cardiac arrest as a tool for studying severe brain damage and other complications secondary to CPB.

Congenital heart disease (CHD) is the most prevalent congenital malformation, with about one million births impacted worldwide per year. Comprehensive ...