Name: hemodynamic precision in the neonatal intensive care unit using targeted neonatal echocardiography
Uploaded: 2023-01-27T12:45:00
Description: Watch this Scientific Journal Video about Hemodynamic Precision in the Neonatal Intensive Care Unit using Targeted Neonatal Echocardiography at JoVE.com

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. M.M. is supported by the National Institute on Minority Health and Health Disparities of the National Institutes of Health under Award Number R25MD011564.
Resources for the figures, reference values, and training recommendations were adapted from Ruoss et al.30, the TnECHO teaching manual47, the Neonatal Hemodynamics Research Center (NHRC)48, and the Targeted neonatal echocardiography application49.

This protocol was approved by the institution&#39;s human research ethics committee, and written consent was obtained from the patient before the procedure.
1. Preparation
<ol>
	<li>For image acquisition, use ultrasound systems that include two-dimensional (2D), M-mode, and full Doppler capabilities, as well as simultaneous electrocardiographic tracing display ability.</li>
	<li>Ensure that multi-frequency probes, 5-6 MHz (for infants &#62;2 kg) and 8-12 MHz (for infants &#6...

TnECHO-guided care has been adopted in many neonatal intensive care units as an adjunct to the clinical assessment of hemodynamic instability in infants by neonatologists4. Accredited training programs have been developed in accordance with the 2011 ASE3 with a focus on a competence-based approach to training. The unique vulnerability of the immature cardiovascular system and the complexity of cardiovascular adaptation during the postnatal transition are key determinants of...

Targeted neonatal echocardiography (TnECHO) refers to the bedside use of echocardiography to longitudinally assess myocardial function, systemic and pulmonary blood flow, and intracardiac and extracardiac shunts1. When TnECHO is integrated with clinical findings, it can provide vital information in diagnosis, the guidance of therapeutic interventions, and the dynamic monitoring of response to treatments2.&#160;TnECHO is frequently performed by trained neonatologists in response to a specific clinical question with the goal of acquiring hemodynamics information that can complement and provide physiologic insights into the clinical status of the patients, resulting in precise cardiovascular care3. Over the past 10-15 years, TnECHO services have been incorporated in multiple tertiary neonatal intensive care units (NICUs) in Australia, New Zealand, Europe, and North America, especially in the management of complex high-acuity cases4,5,6,7,8.&#160;To date, there are eight centers in the USA with trained practitioners providing TnECHO services and a growing number of centers involved in neonatal hemodynamics research. Furthermore, the establishment of the neonatal hemodynamics and TnECHO special interest group (SIG) at the American Society of Echocardiography (ASE) reinforces the academic collaboration with pediatric cardiology and creates a strong political platform for further growth in the field9.
Neonatal hemodynamics training is designed to ensure that individuals who have received the training can achieve high-level imaging and provide comprehensive cardiovascular decision-making. In 2011, training recommendations for TnECHO, endorsed by European and North American professional organizations, were published3. Currently, more than 50 North American neonatologists have completed formal training in TnECHO; of note, more than 50% of hemodynamic clinicians are considered emerging academic leaders in the field, which is an unanticipated but much-needed benefit of formal training. Figure 1 summarizes hemodynamics training and accreditation.
The essential elements of a TnECHO service include access to a dedicated echocardiography machine. This ensures immediate availability for image acquisition and allows longitudinal follow-up (Figure 2 and Figure 3). The database/image archive must include the ability to provide immediate playback without video degradation, standardized reports, and long-term storage as per the recommendations of the Intersocietal Commission for the Accreditation of Echocardiography Laboratories10. A standard TnECHO includes key measurements that allow comprehensive assessments of intricate cardiovascular physiology during the neonatal period. This includes left ventricular (LV) function, right ventricular (RV) function, intracardiac shunt (atrial-level shunt and ductal-level shunt), the hemodynamic effects of patent ductus arteriosus (PDA), right ventricular systolic pressure (RVSp)/pulmonary artery (PA) pressure, systemic and pulmonary blood flow, the presence of pericardial fluid, thrombus, and central line position. Table 1 shows the commonly used echocardiographic terms utilized to acquire some of the data for these measurements. The evaluation may be performed for both symptom- and disease-based indications. Supplementary File 1 and Table 2 outline the comprehensive neonatal echocardiography assessments with recommended measurements, interpretation, and reference ranges for term neonates in the first 7 postnatal days.
The evaluation of LV systolic function is a key component as it assists in the delineation of the etiology and management of hemodynamic instability in critically ill neonates. Quantitative assessment is recommended as qualitative assessment is prone to inter-observer and intra-observer variability11. The calculation of the ejection fraction using a multi-plane method such as Simpson&#39;s biplane or the area-length method is superior to M-mode estimations, which may miss regional wall motion abnormalities and is inaccurate in the presence of septal flattening12. LV diastolic dysfunction is an emerging concept in neonatal hemodynamics. However, the data remain limited13.
An assessment of RV function is crucial in neonatal life because the RV is the dominant ventricle in transitional circulation, and many neonatal diseases are associated with right heart pathology. For a similar reason, in the assessment of LV systolic function, subjective assessment should be avoided14. However, due to the RV&#39;s unusual shape, highly trabeculated surface, and position wrapped around the LV, the measurement of RV function is more difficult. Despite this, several reliable quantitative parameters have been studied, and normative data have been published15,16. Fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE) are two of the recommended quantitative measurements used17.
Intracardiac shunt (atrial and ductal level) is another important aspect of the comprehensive neonatal echocardiography assessment. In most situations, left atrial pressures are higher in comparison to right atrial (RA) pressures, resulting in a left-to-right shunt. However, in the neonatal period, a bidirectional shunt can still be normal. Elevated right-sided filling pressures, especially in association with pulmonary hypertension (PH), should be considered when there is right-to-left shunting at the atrial level, but this should not be used in isolation given that variation in ventricular compliance/pressure may also influence atrial pressure at various points during the cardiac cycle.
An assessment of patent ductus arteriosus (PDA) should include the determination of ductal shunt direction and the measurement of ductal pressure gradients, which are used to assist in treatment decisions. An arch-sidedness evaluation is also important, especially when there is consideration of surgical PDA ligation. PDA shunt direction is reflective of the difference between aortic and PA pressures, as well as the relative resistance of the pulmonary and systemic circulation. One factor used to adjudicate hemodynamic significance is the presence of holodiastolic retrograde flow in the descending thoracic or abdominal aorta18. Hemodynamic significance can be further assessed by quantifying the degree of volume overload by comprehensive measurements19. Scoring systems that assess the surrogate consequences of volume loading on the heart and the systemic hypoperfusion associated with PDA shunt, such as the Iowa PDA score, have been published (Table 3)19,20,21 The Iowa PDA score has been adopted clinically at the University of Iowa to enhance objectivity in determining the hemodynamic significance of a PDA shunt. A score of more than 6 is suggestive of a hemodynamically significant patent ductus arteriosus (hsPDA)19.
In the assessment of pulmonary hemodynamics, the absolute value of RVSp is estimated by the measurement of the tricuspid regurgitant (TR) gradient. Continuous wave Doppler is used to measure the maximal tricuspid regurgitation velocity through the tricuspid valve, referred to as the tricuspid regurgitant peak velocity. An assumed RA pressure of 5 mmHg is typically used for the calculation. The RVSp is then calculated using the simplified Bernoulli equation22:
RVSp = 4 &#215; (tricuspid regurgitant peak velocity [m/s])2 + RA pressure
Occasionally an alternative, the Doppler-derived pressure gradient across a PDA, is used for the calculation of PA (pulmonary artery) pressures23. However, a TR jet is only present in approximately 50% of patients with chronic PH24,25,26. In these situations, measurements such as the end-systolic eccentricity index (sEI), which is a measure of LV circularity, may indicate the relative pressure between the ventricles. This measurement should be interpreted with caution in patients with systemic hypertension as the mild disease may go undetected due to elevated LV end-diastolic pressure. Figure 4 gives an example of an algorithm and comprehensive neonatal echocardiography assessment guidelines for pulmonary hypertension.
For the assessment of LV stroke volume, a pulse Doppler tracing in an apical five-chamber view at the level of the aortic valve is measured to obtain the time-velocity integral (TVI). This is combined with a measurement of aortic annulus diameter in the parasternal long-axis view. A calculation with the following formula is used to estimate LV output27:
LV output (mL/min/kg) = (TVI [cm] &#215; &#960; x [D/2]2 [cm2] &#215; heart rate)/weight.
However, in the presence of a PDA, the LV output measurement is not reflective of systemic blood flow secondary to the shunting at the PDA level3. The diastolic flow to peripheral organs by Doppler interrogation of the celiac artery, superior mesenteric artery, and middle cerebral artery can give an indication of a systemic steal by a PDA but may, alternately, reflect organ resistance, with low or absent diastolic flow seen in the setting of high resistance.
TnECHO can also be utilized to assist in detecting the presence of intracardiac thrombus, pericardial fluid, and its hemodynamic significance, guiding pericardiocentesis, as well as assisting in the placement of peripheral arterial lines, peripherally inserted central catheters, and umbilical venous catheters28.&#160;Here, to show the comprehensive approach to obtaining TnECHO and the hemodynamics information, we describe the imaging protocol and the elements of a TnECHO service (Figure 3).

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			<td>DICOM VIEWER EP</td>
			<td>GEHealthcare</td>
			<td>H45581CC</td>
			<td>DICOM Viewer on MediaThis option provides the ability to export DICOM images including a DICOM viewer to storage media (USB, DVD), for easy access to patient images on offline computers.</td>
		</tr>
		<tr>
			<td>2D Strain</td>
			<td>GEHealthcare</td>
			<td>H45561WF</td>
			<td>Automated 2D EF Measurement tool based upon 2D-Speckle tracking algorithm.</td>
		</tr>
		<tr>
			<td>EchoPAC* Software Only v203</td>
			<td>GEHealthcare</td>
			<td>H8018PF</td>
			<td></td>
		</tr>
		<tr>
			<td>EchoPAC* Advanced Bundle Package</td>
			<td>GEHealthcare</td>
			<td>H8018PG</td>
			<td>Advanced QScan provides dedicated parametric imaging applications for quantitative display of regional wall deformation.</td>
		</tr>
		<tr>
			<td>Multi-Link 3-lead ECG Care cable neonatal DIN, AHA (3.6 m/12 feet)</td>
			<td>GEHealthcare</td>
			<td>H45571RD</td>
			<td>Multi-Link 3-lead ECG Care cable neonatal DIN, AHA (3.6 m/12 feet) Used together with neonatal leads H45571RJ</td>
		</tr>
		<tr>
			<td>Myocardial Work</td>
			<td></td>
			<td>H45591AG&#160;</td>
			<td>Myocardial Work adjusts the AFI (strain) results using the systolic and diastolic blood pressure measured immediately prior to the 
			echo exam. Using the Myocardial Work feature helps achieve a less load dependent strain/ pressure curve and work efficiency index</td>
		</tr>
		<tr>
			<td>12S-D Phased Array Probe</td>
			<td>GEHealthcare</td>
			<td>H45021RT</td>
			<td></td>
		</tr>
		<tr>
			<td>6S-D Phased Array Probe</td>
			<td>GEHealthcare</td>
			<td>H45021RR</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterile ultrasound gel</td>
			<td>Parker labs</td>
			<td>PM-010-0002D</td>
			<td>sterile water solubel single packet ultrasound transmission gel</td>
		</tr>
		<tr>
			<td>Ultrasound gel warmer</td>
			<td>Parker Labs</td>
			<td>SKU 83-20</td>
			<td>ultrasound gel warmer for single gel package.</td>
		</tr>
		<tr>
			<td>Wireless USB adapter</td>
			<td></td>
			<td>H45591HS</td>
			<td>Wireless external G type USB adapter with extension cable and hardware for mounting on the rear panel.</td>
		</tr>
		<tr>
			<td>Vivid* E90 v203 Console Package</td>
			<td>GEHealthcare</td>
			<td>H8018EB</td>
			<td>Vivid E90 w/OLED monitor v203 Console</td>
		</tr>
	</tbody>
</table>

hemodynamic precision in the neonatal intensive care unit using targeted neonatal echocardiography

Targeted neonatal echocardiography (TnECHO) refers to the use of comprehensive echocardiographic evaluation and physiologic data to obtain accurate, reliable, and real-time information on developmental hemodynamics in sick newborns. The comprehensive assessment is based on a multiparametric approach that overcomes the reliability issues of individual measurements, allows for earlier recognition of cardiovascular compromise and promotes enhanced diagnostic precision and timely management. TnECHO-driven research has led to an enhanced understanding of the mechanisms of illness and the development of predictive models to identify at-risk populations. This information may then be used to formulate a diagnostic impression and provide individualized guidance for the selection of cardiovascular therapies. TnECHO is based on the expert consultative model in which a neonatologist, with advanced training in neonatal hemodynamics, performs comprehensive and standardized TnECHO assessments. The distinction from point of care ultrasonography (POCUS), which provides limited and brief one-time assessments, is important. Neonatal hemodynamics training is a 1-year structured program designed to optimize image acquisition, measurement analysis, and hemodynamic knowledge (physiology, pharmacotherapy) to support cardiovascular decision-making. Neonatologists with hemodynamic expertise are trained to recognize deviations from normal anatomy and appropriately refer cases of possible structural abnormalities. We provide an outline of neonatal hemodynamics training, the standardized TnECHO imaging protocol, and an example of representative echo findings in a hemodynamically significant patent ductus arteriosus.

The following representative results outline the evaluation of a hemodynamically significant patent ductus arteriosus (hsPDA) as an example of the use of TnECHO in clinical settings. As mentioned earlier, a comprehensive assessment with multiple measurements is performed to adjudicate hemodynamic significance. The Iowa PDA score (Table 3) is one of the scoring systems adopted into clinical use as it assists in quantifying the consequences of volume loading and systemic hypoperfusion associated with PDA s...

Watch this Scientific Journal Video about Hemodynamic Precision in the Neonatal Intensive Care Unit using Targeted Neonatal Echocardiography at JoVE.com

Hemodynamic Precision in the Neonatal Intensive Care Unit using Targeted Neonatal Echocardiography

Presented here is a protocol to perform comprehensive neonatal echocardiography by trained neonatologists in the neonatal intensive care unit. The trained individuals provide longitudinal assessments of heart function, systemic and pulmonary hemodynamics in a consultative role. The manuscript also describes the requirements to become a fully trained neonatal hemodynamics specialist.

Targeted neonatal echocardiography (TnECHO) refers to the use of comprehensive echocardiographic evaluation and physiologic data to obtain accurate, ...

hemodynamic-precision-neonatal-intensive-care-unit-using-targeted

Research

JoVE Journal

Medicine

A Piglet Model of Neonatal Hypoxic-Ischemic Encephalopathy

Birth asphyxia, which causes hypoxic-ischemic encephalopathy (HIE), accounts for 0.66 million deaths worldwide each year, about a quarter of the world&#8217;s 2.9 million neonatal deaths. Animal models of HIE have contributed to the understanding of the pathophysiology in HIE, and have highlighted the dynamic process that occur in brain injury due to perinatal asphyxia. Thus, animal studies have suggested a time-window for post-insult treatment strategies. Hypothermia has been tested as a treatment for HIE in pdiglet models and subsequently proven effective in clinical trials. Variations of the model have been applied in the study of adjunctive neuroprotective methods and piglet studies of xenon and melatonin have led to clinical phase I and II trials1,2. The piglet HIE model is further used for neonatal resuscitation- and hemodynamic studies as well as in investigations of cerebral hypoxia on a cellular level. However, it is a technically challenging model and variations in the protocol may result in either too mild or too severe brain injury. In this article, we demonstrate the technical procedures necessary for establishing a stable piglet model of neonatal HIE. First, the newborn piglet (&#60; 24 hr old, median weight 1500 g) is anesthetized, intubated, and monitored in a setup comparable to that found in a neonatal intensive care unit. Global hypoxia-ischemia is induced by lowering the inspiratory oxygen fraction to achieve global hypoxia, ischemia through hypotension and a flat trace amplitude integrated EEG (aEEG) indicative of cerebral hypoxia. Survival is promoted by adjusting oxygenation according to the aEEG response and blood pressure. Brain injury is quantified by histopathology and magnetic resonance imaging after 72 hr.

Hypoxic-ischemic encephalopathy following perinatal asphyxia can be studied using animal models. We demonstrate the procedures necessary for establishing a piglet model of neonatal hypoxic-ischemic encephalopathy.

Birth asphyxia, which causes hypoxic-ischemic encephalopathy (HIE), accounts for 0.66 million deaths worldwide each year, about a quarter of the ...

Protocol and Guidelines for Point-of-Care Lung Ultrasound in Diagnosing Neonatal Pulmonary Diseases Based on International Expert Consensus

Ultrasound is a safe bedside imaging tool that obviates the use of ionizing radiation diagnostic procedures. Due to its convenience, the lung ultrasound has received increasing attention from neonatal physicians. Nevertheless, clear reference standards and guideline limits are needed for accurate application of this diagnostic modality. This document aims to summarize expert opinions and to provide precise guidance to help facilitate the use of the lung ultrasound in the diagnosis of neonatal lung diseases.

Lung ultrasound is a noninvasive and valuable tool for bedside evaluation of neonatal lung diseases. However, a relative lack of reference standards, protocols and guidelines may limit its application. Here, we aim to develop a standardized neonatal lung ultrasound diagnostic protocol to be used in clinical decision-making.

Ultrasound is a safe bedside imaging tool that obviates the use of ionizing radiation diagnostic procedures. Due to its convenience, the lung ultrasound ...

A Protocol to Set Up Needle-Free Connector with Positive Displacement on Central Venous Catheter in Intensive Care Unit

Needle-free connectors were initially designed and promoted to avoid blood exposure for healthcare workers. Some recent data suggest that the latest generation of connectors (with positive displacement) may be of interest for reducing central venous line infections. We have been using needle-free connectors for several years in our intensive care unit and here we present a protocol for installing these connectors on central venous catheters. After insertion of the catheter and control of the permeability of the lines, the connectors must be purged with 0.9% NaCl before being connected. The connectors replace all disposable caps used on infusion stopcocks and manifolds. All the connectors are changed every 7 days as recommended by the manufacturer (except when there is macroscopic contamination, which requires an immediate change of the connector). Before each injection, the connector must be disinfected for at least 3 seconds with 70% isopropyl alcohol. The connectors must not be disconnected (unless changed), as the injection is done through the device. Setting up the connectors slightly increases the total time required to place the catheter and there is no formal evidence that these connectors reduce the incidence of infectious or thrombotic complications. However, these devices simplify the management of central venous lines and prevent the catheter circuit from &#34;opening&#34; once it has been sterilely installed.

We present a protocol to show the installation of a needle-free connector with positive displacement on a central venous catheter.

Needle-free connectors were initially designed and promoted to avoid blood exposure for healthcare workers. Some recent data suggest that the latest ...

Clinical Practice Protocol of Creative Music Therapy for Preterm Infants and Their Parents in the Neonatal Intensive Care Unit

Creative music therapy for preterm infants and their parents (CMT) has emerged as a promising family-integrated early intervention involving communicative musicality to improve infant development, parental well-being, and bonding. It aims at relaxing and nurturing the infant as well as promoting safety and social interaction for the parent-infant dyad. A music therapist specially trained in CMT hums or sings in an infant-directed, improvised, lullaby style continually adjusting to the individual needs, expressions, and breathing pattern of the preterm infant. Based on the principles of family-integrated care, the family is incorporated individually in the therapeutic process, namely by delivering CMT during kangaroo care (KC) and by motivating and facilitating parental vocal interaction with their infant to strengthen the parent-infant bonding. CMT aims at relaxing, stimulating, and coregulating premature infants at a time when many other interventions are still risky and can overwhelm the vulnerable patient group. CMT may be advantageous not by educating and teaching parents, but rather by uncovering the intuitive capacities of parenting that are often overshadowed by the traumatic experience of preterm birth. However, CMT can only be provided when the infants are clinically stable. CMT with parental integration is feasible when parents are available and receptive to participate. This paper presents a detailed protocol on how to use CMT to empower preterm infants and their families.

Creative music therapy for preterm infants and their parents has emerged as a promising family-integrated early intervention. We present a detailed protocol on how to use vocal interaction, humming, or singing to empower preterm infants and their families.

Creative music therapy for preterm infants and their parents (CMT) has emerged as a promising family-integrated early intervention involving communicative ...

International Expert Consensus and Recommendations for Neonatal Pneumothorax Ultrasound Diagnosis and Ultrasound-guided Thoracentesis Procedure

Pneumothorax (PTX) represents accumulation of the air in the pleural space. A large or tension pneumothorax can collapse the lung and cause hemodynamic compromise, a life-threatening disorder. Traditionally, neonatal pneumothorax diagnosis has been based on clinical images, auscultation, transillumination, and chest X-ray findings. This approach may potentially lead to a delay in both diagnosis and treatment. The use of lung US in diagnosis of PTX together with US-guided thoracentesis results in earlier and more precise management. The recommendations presented in this publication are aimed at improving the application of lung US in guiding neonatal PTX diagnosis and management.

Pneumothorax is a common emergency and critical disease in newborn infants that needs rapid, clear diagnosis and timely treatment. Diagnosis and treatment based on chest X-rays are associated with delayed management and radiation damage. Lung ultrasound (US) provides useful guidance for rapid, accurate diagnosis and the precise thoracentesis of pneumothorax.

Pneumothorax (PTX) represents accumulation of the air in the pleural space. A large or tension pneumothorax can collapse the lung and cause hemodynamic ...

Halogenated Agent Delivery in Porcine Model of Acute Respiratory Distress Syndrome via an Intensive Care Unit Type Device

Acute respiratory distress syndrome (ARDS) is a common cause of hypoxemic respiratory failure and death in critically ill patients, and there is an urgent need to find effective therapies. Preclinical studies have shown that inhaled halogenated agents may have beneficial effects in animal models of ARDS. The development of new devices to administer halogenated agents using modern intensive care unit (ICU) ventilators has significantly simplified the dispensing of halogenated agents to ICU patients. Because previous experimental and clinical research suggested potential benefits of halogenated volatiles, such as sevoflurane or isoflurane, for lung alveolar epithelial injury and inflammation, two pathophysiologic landmarks of diffuse alveolar damage during ARDS, we designed an animal model to understand the mechanisms of the effects of halogenated agents on lung injury and repair. After general anesthesia, tracheal intubation, and the initiation of mechanical ventilation, ARDS was induced in piglets via the intratracheal instillation of hydrochloric acid. Then, the piglets were sedated with inhaled sevoflurane or isoflurane using an ICU-type device, and the animals were ventilated with lung-protective mechanical ventilation during a 4 h period. During the study period, blood and alveolar samples were collected to evaluate arterial oxygenation, the permeability of the alveolar-capillary membrane, alveolar fluid clearance, and lung inflammation. Mechanical ventilation parameters were also collected throughout the experiment. Although this model induced a marked decrease in arterial oxygenation with altered alveolar-capillary permeability, it is reproducible and is characterized by a rapid onset, good stability over time, and no fatal complications.
We have developed a piglet model of acid aspiration that reproduces most of the physiological, biological, and pathological features of clinical ARDS, and it will be helpful to further our understanding of the potential lung-protective effects of halogenated agents delivered through devices used for inhaled ICU sedation.

We describe a model of hydrochloric acid-induced acute respiratory distress syndrome (ARDS) in piglets receiving sedation with halogenated agents, isoflurane and sevoflurane, through a device used for inhaled intensive care sedation. This model can be used to investigate the biological mechanisms of halogenated agents on lung injury and repair.

Acute respiratory distress syndrome (ARDS) is a common cause of hypoxemic respiratory failure and death in critically ill patients, and there is an urgent ...

Organ Ischemia-Reperfusion Injury by Simulating Hemodynamic Changes in Rat Liver Transplant Model

Orthotopic liver transplantation (OLT) in rats is a tried and proven animal model used for preoperative, intraoperative, and postoperative studies, including ischemia-reperfusion injury (IRI) of extrahepatic organs. This model requires numerous experiments and devices. The duration of anhepatic phase is closely related to the time to develop IRI after transplantation. In this experiment, we used hemodynamic changes to induce extrahepatic organ damage in rats and determined the maximum tolerance time. The time until the most severe organ injury varied for different organs. This method can easily be replicated and can also be used to study IRI of the extrahepatic organs after liver transplantation.

This paper provides a detailed description of how to build an animal model of the anhepatic phase (liver ischemia) in rats to facilitate basic research into ischemia-reperfusion injury after liver transplantation.

Orthotopic liver transplantation (OLT) in rats is a tried and proven animal model used for preoperative, intraoperative, and postoperative studies, ...

Blind Endotracheal Intubation in Neonatal Rabbits

The newborn rabbit is a useful animal model for various pathologies and procedures. Airway management of the rabbit is complex due to its anatomical characteristics, which is further complicated in the case of the newborn. Of the different methods of advanced airway management, endotracheal intubation is less aggressive than tracheostomy, and is more feasible than supraglottic management given the lack of supraglottic devices of such a small size. As direct glottis visualization is very difficult in animals this size, this blind intubation model is presented as an effective alternative, especially for experiments requiring prolonged anesthesia. Using this method, we performed blind intubations with a 90% success rate.

We describe a technique of endotracheal intubation in newborn rabbits after esophageal catheterization with a gastric tube.

The newborn rabbit is a useful animal model for various pathologies and procedures. Airway management of the rabbit is complex due to its anatomical ...

A Reproducible Intensive Care Unit-Oriented Endotoxin Model in Rats

Sepsis and septic shock remain the leading cause of death in intensive care units. Despite significant improvements in sepsis management, mortality still ranges between 20 and 30%. Novel treatment approaches in order to reduce sepsis-related multiorgan failure and death are urgently needed. Robust animal models allow for one or multiple treatment approaches as well as for testing their effect on physiological and molecular parameters. In this article, a simple animal model is presented.
First, general anesthesia is induced in animals either with the use of volatile or by intraperitoneal anesthesia. After placement of an intravenous catheter (tail vein), tracheostomy, and insertion of an intraarterial catheter (tail artery), mechanical ventilation is started. Baseline values of mean arterial blood pressure, arterial blood oxygen saturation, and heart rate are recorded.
The injection of lipopolysaccharides (1 milligram/kilogram body weight) dissolved in phosphate-buffered saline induces a strong and reproducible inflammatory response via the toll-like receptor 4. Fluid corrections as well as the application of norepinephrine are performed based on well-established protocols.
The animal model presented in this article is easy to learn and strongly oriented towards clinical sepsis treatment in an intensive care unit with sedation, mechanical ventilation, continuous blood pressure monitoring, and repetitive blood sampling. Also, the model is reliable, allowing for reproducible data with a limited number of animals in accordance with the 3R (reduce, replace, refine) principles of animal research. While animal experiments in sepsis research cannot easily replaced, repetitive measurements allow for a reduction of animals and keeping septic animals anesthetized diminishes suffering.

Here, we present a reproducible intensive care unit-oriented endotoxin model in rats.

Sepsis and septic shock remain the leading cause of death in intensive care units. Despite significant improvements in sepsis management, mortality still ...

Effect of Hyaluronic Acid 35 kDa on an In Vitro Model of Preterm Small Intestinal Injury and Healing Using Enteroid-Derived Monolayers

In vitro scratch wound assays are commonly used to investigate the mechanisms and characteristics of epithelial healing in a variety of tissue types. Here, we describe a protocol to generate a two-dimensional (2D) monolayer from three-dimensional (3D) non-human primate enteroids derived from intestinal crypts of the terminal ileum. These enteroid-derived monolayers were then utilized in an in vitro scratch wound assay to test the ability of hyaluronan 35 kDa (HA35), a human milk HA mimic, to promote cell migration and proliferation along the epithelial wound edge. After the monolayers were grown to confluency, they were manually scratched and treated with HA35 (50 &#181;g/mL, 100 &#181;g/mL, 200 &#181;g/mL) or control (PBS). Cell migration and proliferation into the gap were imaged using a transmitted-light microscope equipped for live-cell imaging. Wound closure was quantified as percent wound healing using the Wound Healing Size Plugin in ImageJ.&#160;The scratch area and rate of cell migration and the percentage of wound closure were measured over 24 h. HA35 in vitro accelerates wound healing in small intestinal enteroid monolayers, likely through a combination of cell proliferation at the wound edge and migration to the wound area. These methods can potentially be used as a model to explore intestinal regeneration in the preterm human small intestine.

Effect of Hyaluronic Acid 35 kDa on an In Vitro Model of Preterm Small Intestinal Injury and Healing Using Enteroid-Derived Monolayers

This protocol describes a method to establish and perform a scratch wound assay on two-dimensional (2D) monolayers derived from three-dimensional (3D) enteroids isolated from non-human primate ileum.

In vitro scratch wound assays are commonly used to investigate the mechanisms and characteristics of epithelial healing in a variety of tissue types. ...