We would like to acknowledge all the colleagues in the NICU for their work.

This protocol was approved by the Institutional Review Board of Renji Hospital, Shanghai Jiaotong University School of Medicine.
1. Preparation of the Patient
NOTE: ICP sensor is placed in the patient by a surgical operation (Figure 1). The sensor is placed in the epidural space, subdural space, parenchyma, or ventricular system.
<ol>
	<li>Connect the ICP monitoring machine with the bedside monitor via a specific communication cable.</li>
	<li>Adjust the reference of patient&#39;s bedside monitor, so that the data from the bedside monitor are in accordance with the ICP monitoring machine.</li>
	<li>Perform an arterial line placement on patient&#39;s left or right radial artery20.</li>
	<li>Connect the arterial line with the baroreceptor.</li>
	<li>Connect the pressure transducer with patient&#39;s bedside monitor via a communication cable.</li>
	<li>Zero adjust the bedside monitor so that the measured blood pressure coincides with the actual value.</li>
</ol>
2. Recording of Physiological Parameters
<ol>
	<li>Connect the patient&#39;s bedside monitor with the data collecting and storing device via a network cable.</li>
	<li>Press the power button to turn on the data collecting device.</li>
	<li>Wait for a few seconds until the multimodality monitoring software runs automatically.</li>
	<li>Enter the information of the patient, including the name, ID, diagnosis, and initial Glasgow Coma Scale (GCS).</li>
	<li>Click the &#34;Save and start monitoring&#34; button to start data collecting and storing.</li>
	<li>Click the &#34;Turn off&#34; button on the screen at the end of the data acquisition (Figure 2).</li>
	<li>Enter the final GCS.</li>
</ol>
3. Parameter Analysis
<ol>
	<li>Dump the stored data to a U-disk through universal serial bus (USB) interfaces on the host.</li>
	<li>Enter a user name and password to log in to the analysis server.</li>
	<li>Click the &#34;Create new record&#34; button and select the data file in the U-disk to start uploading.</li>
	<li>Wait for around 10 to 20 min before the data are analyzed (depending on the data size).</li>
	<li>Click the &#34;Detail&#34; button of each record to see the result.</li>
	<li>Click the &#34;Chart viewing&#34; to see the final diagram.</li>
	<li>Drag the timeline to see more detail.</li>
	<li>Click the &#34;scattergram&#34; button to see the distribution of the parameters.</li>
</ol>

<ol>
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Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Head+trauma+in+China.">Head trauma in China.</a> Injury. 44 (11), 1453-1457 (2013).</li><li>Hu, X., Xu, P., Asgari, S., Vespa, P., Bergsneider, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Forecasting+ICP+elevation+based+on+prescient+changes+of+intracranial+pressure+waveform+morphology.">Forecasting ICP elevation based on prescient changes of intracranial pressure waveform morphology.</a> IEEE Trans Biomed Eng. 57 (5), 1070-1078 (2010).</li><li>Di Ieva, A., Schmitz, E. M., Cusimano, M. 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K., Sorteberg, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Association+among+intracranial+compliance,+intracranial+pulse+pressure+amplitude+and+intracranial+pressure+in+patients+with+intracranial+bleeds.">Association among intracranial compliance, intracranial pulse pressure amplitude and intracranial pressure in patients with intracranial bleeds.</a> Neurol Res. 29 (8), 798-802 (2007).</li><li>Czosnyka, M., Czosnyka, Z. H., Whitfield, P. C., Donovan, T., Pickard, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age+dependence+of+cerebrospinal+pressure-volume+compensation+in+patients+with+hydrocephalus.">Age dependence of cerebrospinal pressure-volume compensation in patients with hydrocephalus.</a> J Neurosurg. 94 (3), 482-486 (2001).</li><li>Howells, T., Lewen, A., Skold, M. 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D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monitoring+and+interpretation+of+intracranial+pressure.">Monitoring and interpretation of intracranial pressure.</a> J Neurol Neurosurg Psychiatry. 75 (6), 813-821 (2004).</li><li>Sorrentino, E., 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=Critical+thresholds+for+cerebrovascular+reactivity+after+traumatic+brain+injury.">Critical thresholds for cerebrovascular reactivity after traumatic brain injury.</a> Neurocrit Care. 16 (2), 258-266 (2012).</li><li>Carrera, E., 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=What+shapes+pulse+amplitude+of+intracranial+pressure.">What shapes pulse amplitude of intracranial pressure.</a> J Neurotrauma. 27 (2), 317-324 (2010).</li><li>Eide, P. 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=Pressure-derived+versus+pressure+wave+amplitude-derived+indices+of+cerebrovascular+pressure+reactivity+in+relation+to+early+clinical+state+and+12-month+outcome+following+aneurysmal+subarachnoid+hemorrhage.">Pressure-derived versus pressure wave amplitude-derived indices of cerebrovascular pressure reactivity in relation to early clinical state and 12-month outcome following aneurysmal subarachnoid hemorrhage.</a> J Neurosurg. 116 (5), 961-971 (2012).</li><li>Lazaridis, 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=Patient-specific+thresholds+of+intracranial+pressure+in+severe+traumatic+brain+injury.">Patient-specific thresholds of intracranial pressure in severe traumatic brain injury.</a> J Neurosurg. 120 (4), 893-900 (2014).</li><li>Czosnyka, M., 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=Monitoring+and+interpretation+of+intracranial+pressure+after+head+injury.">Monitoring and interpretation of intracranial pressure after head injury.</a> Acta Neurochir Suppl. 96, 114-118 (2006).</li><li>Steiner, L. 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=Continuous+monitoring+of+cerebrovascular+pressure+reactivity+allows+determination+of+optimal+cerebral+perfusion+pressure+in+patients+with+traumatic+brain+injury.">Continuous monitoring of cerebrovascular pressure reactivity allows determination of optimal cerebral perfusion pressure in patients with traumatic brain injury.</a> Crit Care Med. 30 (4), 733-738 (2002).</li><li>Tegtmeyer, K., Brady, G., Lai, S., Hodo, R., Braner, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Videos+in+Clinical+Medicine.+Placement+of+an+arterial+line.">Videos in Clinical Medicine. Placement of an arterial line.</a> N Engl J Med. 354 (15), 13 (2006).</li><li>Chesnut, R. M., 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+trial+of+intracranial-pressure+monitoring+in+traumatic+brain+injury.">A trial of intracranial-pressure monitoring in traumatic brain injury.</a> N Engl J Med. 367 (26), 2471-2481 (2012).</li></ol>

No financial support was received.

This aim of this article is to introduce the new multimodality monitoring and analyzing system for neurosurgical critical patients, which can be used to monitor physiological parameters, analyze the current clinical status and, hopefully, predict the prognosis of the neurosurgical critical patients. Nowadays, the focus of ICP monitoring is mainly on the mean ICP value while ignoring other parameters, which may carry risks of inaccuracy or delay4,5,<sup...

ICP monitoring is widely used to evaluate intracranial status in neurosurgery department, especially in neurosurgical critical patients1,2,3. Besides mean ICP value, the ICP derived parameters such as ICP waveform, AMP, RAP, PRx, IAAC, and so on, can reflect the status of intracerebral circulation, cerebrospinal compensatory reserve, and brain compliance4,5,6,7,8,9,10,11,12,13. They can be indicative of impending neurological deterioration and even outcome of patients14,15,16,17,18. They can also be used as guidance of proper treatment19. However, most of the clinicians focus only on the mean ICP value while ignoring these parameters. This is partly because there are few specific devices that are suitable for clinicians in their daily clinical work.
To address these drawbacks, we have recently developed a multimodality monitoring system. We use an automatic data collecting and storing device to continuously acquire patients&#39; physiological information such as blood pressure, ICP, and oxygen saturation, and analyze these physiological parameters in order to reveal the current clinical status and, hopefully, predict the prognosis of the neurosurgical critical patients. This multimodality monitoring system has several advantages: (1) it can collect real-time data at high frequency, (2) it can record multiple parameters, i.e., ICP waveform, PRx, RAP, and IAAC, (3) it can achieve long term continuous monitoring, and (4) it is portable and easy to learn.
The objective of this article, therefore, is to show a detailed method of how to use the multimodality monitoring system to record various physiological parameters in neurosurgical critical patients.

<table><tbody><tr><td>Bedside monitor</td><td>Philips</td><td>IntelliVue MP40 M8003A</td><td>With interfacing module</td></tr><tr><td>ICP monitoring machine</td><td>&amp;nbsp;Johnson &amp;amp; Johnson or Sophysa</td><td></td><td></td></tr><tr><td>Arterial cannula</td><td>BD</td><td>REF682245</td><td></td></tr><tr><td>Pressure transducer</td><td>Haisheng Medical</td><td>DBPT-0103</td><td></td></tr><tr><td>Data collection device</td><td>Shanghai Haoju</td><td>Neumatic</td><td></td></tr><tr><td>Computer</td><td></td><td></td><td>Requires Windows operating system</td></tr></tbody></table>

a detailed protocol for physiological parameters acquisition and analysis in neurosurgical critical patients

Intracranial pressure (ICP) monitoring is now widely used in neurosurgical critical patients. Besides mean ICP value, the ICP derived parameters such as ICP waveform, amplitude of pulse (AMP), the correlation of ICP amplitude and ICP mean (RAP), pressure reactivity index (PRx), ICP and arterial blood pressure (ABP) wave amplitude correlation (IAAC), and so on, can reflect intracranial status, predict prognosis, and can also be used as guidance of proper treatment. However, most of the clinicians focus only on the mean ICP value while ignoring these parameters because of the limitations of the current devices. We have recently developed a multimodality monitoring system to address these drawbacks. This portable, user-friendly system will use a data collecting and storing device to continuously acquire patients&#39; physiological parameters first, i.e., ABP, ICP, and oxygen saturation, and then analyze these physiological parameters. We hope that the multimodality monitoring system will be accepted as a key measure to monitor physiological parameters, to analyze the current clinical status, and to predict the prognosis of the neurosurgical critical patients.

This new multimodality monitoring system was applied on 22 neurosurgical critical patients (15 males). 12 of them (54.55%) had suffered from traumatic brain injury (TBI), 9 of them (40.91%) had intracranial hemorrhage and 1 of them (4.55%) had severe cerebral infarction. The total monitoring time is more than 1,900 h (about 88 h per patient). After successful surgery, we continuously monitored and analyzed their ICP, BP, CPP, PRx, RAP, and IAAC. Figure 3 show...

Watch this Scientific Journal Video about A Detailed Protocol for Physiological Parameters Acquisition and Analysis in Neurosurgical Critical Patients at JoVE.com

A Detailed Protocol for Physiological Parameters Acquisition and Analysis in Neurosurgical Critical Patients

Recently, we have developed a portable multimodality monitoring system for the monitoring of various physiological parameters in neurosurgical critical patients. Detailed protocols on how to use this multimodality monitoring system are presented here.

Intracranial pressure (ICP) monitoring is now widely used in neurosurgical critical patients. Besides mean ICP value, the ICP derived parameters such as ...

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Medicine

6.8K Views.  Shanghai Jiaotong University School of Medicine. Recently, we have developed a portable multimodality monitoring system for the monitoring of various physiological parameters in neurosurgical critical patients. Detailed protocols on how to use this multimodality monitoring system are presented here.

Video: A Detailed Protocol for Physiological Parameters Acquisition and Analysis in Neurosurgical Critical Patients

Performing Behavioral Tasks in Subjects with Intracranial Electrodes

Patients having stereo-electroencephalography (SEEG) electrode, subdural grid or depth electrode implants have a multitude of electrodes implanted in different areas of their brain for the localization of their seizure focus and eloquent areas. After implantation, the patient must remain in the hospital until the pathological area of brain is found and possibly resected. During this time, these patients offer a unique opportunity to the research community because any number of behavioral paradigms can be performed to uncover the neural correlates that guide behavior. Here we present a method for recording brain activity from intracranial implants as subjects perform a behavioral task designed to assess decision-making and reward encoding. All electrophysiological data from the intracranial electrodes are recorded during the behavioral task, allowing for the examination of the many brain areas involved in a single function at time scales relevant to behavior. Moreover, and unlike animal studies, human patients can learn a wide variety of behavioral tasks quickly, allowing for the ability to perform more than one task in the same subject or for performing controls. Despite the many advantages of this technique for understanding human brain function, there are also methodological limitations that we discuss, including environmental factors, analgesic effects, time constraints and recordings from diseased tissue. This method may be easily implemented by any institution that performs intracranial assessments; providing the opportunity to directly examine human brain function during behavior.

Patients implanted with intracranial electrodes provide a unique opportunity to record neurological data from multiple areas of the brain while the patient performs behavioral tasks. Here, we present a method of recording from implanted patients that can be reproducible at other institutions with access to this patient population.

Patients having stereo-electroencephalography (SEEG) electrode, subdural grid or depth electrode implants have a multitude of electrodes implanted in ...

Behavior

Combined Invasive Subcortical and Non-invasive Surface Neurophysiological Recordings for the Assessment of Cognitive and Emotional Functions in Humans

In spite of the success in applying non-invasive electroencephalography (EEG), magneto-encephalography (MEG) and functional magnetic resonance imaging (fMRI) for extracting crucial information about the mechanism of the human brain, such methods remain insufficient to provide information about physiological processes reflecting cognitive and emotional functions at the subcortical level. In this respect, modern invasive clinical approaches in humans, such as deep brain stimulation (DBS), offer a tremendous possibility to record subcortical brain activity, namely local field potentials (LFPs) representing coherent activity of neural assemblies from localized basal ganglia or thalamic regions. Notwithstanding the fact that invasive approaches in humans are applied only after medical indication and thus recorded data correspond to altered brain circuits, valuable insight can be gained regarding the presence of intact brain functions in relation to brain oscillatory activity and the pathophysiology of disorders in response to experimental cognitive paradigms. In this direction, a growing number of DBS studies in patients with Parkinson&#39;s disease (PD) target not only motor functions but also higher level processes such as emotions, decision-making, attention, memory and sensory perception. Recent clinical trials also emphasize the role of DBS as an alternative treatment in neuropsychiatric disorders ranging from obsessive compulsive disorder (OCD) to chronic disorders of consciousness (DOC). Consequently, we focus on the use of combined invasive (LFP) and non-invasive (EEG) human brain recordings in assessing the role of cortical-subcortical structures in cognitive and emotional processing trough experimental paradigms (e.g. speech stimuli with emotional connotation or paradigms of cognitive control such as the Flanker task), for patients undergoing DBS treatment.

The present protocol aims at assessing cognitive-emotional functions in the basal ganglia by simultaneous neurophysiological recording of local field potentials and non-invasive brain cortical activity (EEG). The procedure is exemplified by the use of paradigms involving speech stimuli with emotional connotation or the Flanker task involving cognitive control.

In spite of the success in applying non-invasive electroencephalography (EEG), magneto-encephalography (MEG) and functional magnetic resonance imaging ...

Electrophysiology on Isolated Brainstem-spinal Cord Preparations from Newborn Rodents Allows Neural Respiratory Network Output Recording

While it is well known that the central respiratory drive is located in the brainstem, several aspects of its basic function, development, and response to stimuli remain to be fully understood. To overcome the difficulty of accessing the brainstem in the whole animal, isolation of the brainstem and part of the spinal cord is performed. This preparation is maintained in artificial cerebro-spinal fluid where gases, concentrations, and temperature are controlled and monitored. The output signal from the respiratory network is recorded by a suction electrode placed on the fourth ventral root. In this manner, stimuli can be directly applied onto the brainstem, and the effect can be recorded directly. The signal recorded is linked to the inspiratory signal sent to the diaphragm via the phrenic nerve, and can be described as bursts (around 8 bursts per minute). Analysis of these bursts (frequency, amplitude, length, and area under the curve) allows precise characterization of the stimulus effect on the respiratory network. The main limitation of this method is the viability of the preparation beyond the early post-natal stages. Thus, this method greatly focuses on the study of the whole network without the peripheral inputs in the newborn rat.

The central respiratory drive is located in the brainstem. Spontaneous respiratory motor output from an isolated brainstem-spinal cord is recorded by placing an electrode on the fourth ventral root. This experimental approach is valuable for pharmacological investigations or the assessment of respiratory challenges and genetic manipulations on rhythmic motor behavior.

While it is well known that the central respiratory drive is located in the brainstem, several aspects of its basic function, development, and response to ...

Neuroscience

Simultaneous Recordings of Cortical Local Field Potentials, Electrocardiogram, Electromyogram, and Breathing Rhythm from a Freely Moving Rat

Monitoring the physiological dynamics of the brain and peripheral tissues is necessary for addressing a number of questions about how the brain controls body functions and internal organ rhythms when animals are exposed to emotional challenges and changes in their living environments. In general experiments, signals from different organs, such as the brain and the heart, are recorded by independent recording systems that require multiple recording devices and different procedures for processing the data files. This study describes a new method that can simultaneously monitor electrical biosignals, including tens of local field potentials in multiple brain regions, electrocardiograms that represent the cardiac rhythm, electromyograms that represent awake/sleep-related muscle contraction, and breathing signals, in a freely moving rat. The recording configuration of this method is based on a conventional micro-drive array for cortical local field potential recordings in which tens of electrodes are accommodated, and the signals obtained from these electrodes are integrated into a single electrical board mounted on the animal's head. Here, this recording system was improved so that signals from the peripheral organs are also transferred to an electrical interface board. In a single surgery, electrodes are first separately implanted into the appropriate body parts and the target brain areas. The open ends of all of these electrodes are then soldered to individual channels of the electrical board above the animal's head so that all of the signals can be integrated into the single electrical board. Connecting this board to a recording device allows for the collection of all of the signals into a single device, which reduces experimental costs and simplifies data processing, because all data can be handled in the same data file. This technique will aid the understanding of the neurophysiological correlates of the associations between central and peripheral organs.

This study introduces a method for the simultaneous recording of local field potentials in the brain, electrocardiograms, electromyograms, and breathing signals of a freely moving rat. This technique, which reduces experimental costs and simplifies data analysis, will contribute to the understanding of the interactions between the brain and peripheral organs.

Monitoring the physiological dynamics of the brain and peripheral tissues is necessary for addressing a number of questions about how the brain controls ...

A Bedside, Single Burr Hole Approach to Multimodality Monitoring in Severe Brain Injury

Intracranial pressure (ICP) monitoring is a cornerstone of the intensive care management of patients with severe acute brain injuries, including traumatic brain injury. While elevations in ICP are common, data regarding the measurement and treatment of these ICP elevations are conflicting. There is increasing recognition that changes in the balance between supply and demand of brain tissue are critically important and therefore the measurement of multiple modalities is required. Approaches are not standard, and therefore this article provides a description of a bedside, single burr hole approach to multimodality monitoring that allows the passage of probes designed to measure not only ICP but brain tissue oxygen, blood flow, and intracranial electroencephalography. Patient selection criteria, operative procedures, and practical considerations for securing probes during critical care are described. This method is readily performed, safe, secure, and flexible for the adoption of a variety of multimodality monitoring approaches aimed at detecting or preventing secondary brain injuries.

A method of recording multimodality monitoring signals in patients with severe brain injuries using a bedside, single burr hole technique is described.

Intracranial pressure (ICP) monitoring is a cornerstone of the intensive care management of patients with severe acute brain injuries, including traumatic ...

Standardized Hemorrhagic Shock Induction Guided by Cerebral Oximetry and Extended Hemodynamic Monitoring in Pigs

Hemorrhagic shock ranks among the main reasons for severe injury-related death. The loss of circulatory volume and oxygen carriers can lead to an insufficient oxygen supply and irreversible organ failure. The brain exerts only limited compensation capacities and is particularly at high risk of severe hypoxic damage.This article demonstrates the reproducible induction of life-threatening hemorrhagic shock in a porcine model by means of calculated blood withdrawal. We titrate shock induction guided by near-infrared spectroscopy&#160;and extended hemodynamic monitoring to display systemic circulatory failure, as well as cerebral microcirculatory oxygen depletion. In comparison to similar models that primarily focus on predefined removal volumes for shock induction, this approach highlights a titration by means of the resulting failure of macro- and microcirculation.

Hemorrhagic shock is a severe complication in seriously injured patients, which leads to life-threatening oxygen undersupply. We present a standardized method to induce hemorrhagic shock via blood withdrawal in pigs that is guided by hemodynamics and microcirculatory cerebral oxygenation.

Hemorrhagic shock ranks among the main reasons for severe injury-related death. The loss of circulatory volume and oxygen carriers can lead to an ...

Assessing Cerebral Autoregulation via Oscillatory Lower Body Negative Pressure and Projection Pursuit Regression

The process by which cerebral perfusion is maintained constant over a wide range of systemic pressures is known as &#8220;cerebral autoregulation.&#8221; Effective dampening of flow against pressure changes occurs over periods as short as ~15 sec and becomes progressively greater over longer time periods. Thus, slower changes in blood pressure are effectively blunted and faster changes or fluctuations pass through to cerebral blood flow relatively unaffected. The primary difficulty in characterizing the frequency dependence of cerebral autoregulation is the lack of prominent spontaneous fluctuations in arterial pressure around the frequencies of interest (less than ~0.07 Hz or ~15 sec). Oscillatory lower body negative pressure (OLBNP) can be employed to generate oscillations in central venous return that result in arterial pressure fluctuations at the frequency of OLBNP. Moreover, Projection Pursuit Regression (PPR) provides a nonparametric method to characterize nonlinear relations inherent in the system without a priori assumptions and reveals the characteristic non-linearity of cerebral autoregulation. OLBNP generates larger fluctuations in arterial pressure as the frequency of negative pressure oscillations become slower; however, fluctuations in cerebral blood flow become progressively lesser. Hence, the PPR shows an increasingly more prominent autoregulatory region at OLBNP frequencies of 0.05 Hz and below (20 sec cycles). The goal of this approach it to allow laboratory-based determination of the characteristic nonlinear relationship between pressure and cerebral flow and could provide unique insight to integrated cerebrovascular control as well as to physiological alterations underlying impaired cerebral autoregulation (e.g., after traumatic brain injury, stroke, etc.).

Cerebral perfusion is maintained across a range of pressures via cerebral autoregulation. However, characterizing autoregulation requires prominent pressure fluctuations at regulated frequencies. The described protocol will show how oscillatory lower body negative pressure can generate pressure fluctuations to provide data for projection pursuit regression for quantification of the autoregulatory curve.

The process by which cerebral perfusion is maintained constant over a wide range of systemic pressures is known as &#8220;cerebral autoregulation.&#8221; ...

Biology

How to Administer Near-Infrared Spectroscopy in Critically ill Neonates, Infants, and Children

Near infrared spectroscopy (NIRS) calculates regional tissue oxygenation (rSO2) using the different absorption spectra of oxygenated and deoxygenated hemoglobin molecules. A probe placed on the skin emits light that is absorbed, scattered, and reflected by the underlying tissue. Detectors in the probe sense the amount of reflected light: this reflects the organ-specific ratio of oxygen supply and consumption - independent of pulsatile flow. Modern devices enable the simultaneous monitoring at different body sites. A rise or dip in the rSO2 curve visualizes changes in oxygen supply or demand before vital signs indicate them. The evolution of rSO2 values in relation to the starting point is more important for interpretation than are absolute values.
A routine clinical application of NIRS is the surveillance of somatic and cerebral oxygenation during and after cardiac surgery. It is also administered in preterm infants at risk for necrotizing enterocolitis, newborns with hypoxic ischemic encephalopathy and a potential risk of impaired tissue oxygenation. In the future, NIRS could be increasingly used in multimodal neuromonitoring, or applied to monitor patients with other conditions (e.g., after resuscitation or traumatic brain injury).

This protocol is designed to assist clinicians to measure regional tissue oxygenation at different body sites in infants and children. It can be used in situations where tissue oxygenation is potentially compromised, particularly during cardiopulmonary bypass, when using non-pulsatile cardiac-assist devices, and in critically ill neonates, infants and children.

Near infrared spectroscopy (NIRS) calculates regional tissue oxygenation (rSO2) using the different absorption spectra of oxygenated and deoxygenated ...

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 ...

Intra-Abdominal Pressure Measurements in Neurocritical Patients

Intra-abdominal pressure (IAP) is increasingly being recognized as an indispensable and significant physiological parameter in intensive care units (ICU). IAP has been measured in a variety of ways with the development of many techniques in recent years. The level of intra-abdominal pressure under normal conditions is generally equal to or less than 12 mmHg. Accordingly, abdominal hypertension (IAH) is defined as two consecutive IAP measurements higher than 12 mmHg within 4-6 h. When IAH deteriorates further with IAP higher than 20 mmHg along with organ dysfunction and/or failure, this clinical manifestation can be diagnosed as abdominal compartment syndrome (ACS). IAH and ACS are associated with gastrointestinal ischemia, acute renal failure, and lung injury, leading to severe morbidity and mortality. Elevated IAP and IAH may affect the cerebral venous return and outflow of the cerebrospinal fluid by increasing the intrathoracic pressure (ITP), ultimately leading to increased intracranial pressure (ICP). Therefore, it is essential to monitor IAP in critically ill patients. The reproducibility and accuracy of intra-bladder pressure (IBP) measurements in previous studies need to be further improved, although the indirect measurement of IAP is now a widely used technique. To address these limitations, we recently used a set of IAP monitoring systems with advantages of convenience, continuous monitoring, digital visualization, and long-term IAP recording and data storage in critically ill patients. This IAP monitoring system can detect intra-abdominal hypertension and potentially analyze clinical status in real time. The recorded IAP data and other physiological indicators, such as intracranial pressure, can be further used for correlation analysis to guide treatment and predict a patient&#39;s possible prognosis.

This protocol details the use of a set of intra-abdominal pressure monitoring systems with advantages of convenience, continuous monitoring, digital visualization, and long-term IAP recording and data storage in neurocritical patients to detect intra-abdominal hypertension, which is used for correlation analysis to guide treatment and predict prognoses.

Intra-abdominal pressure (IAP) is increasingly being recognized as an indispensable and significant physiological parameter in intensive care units (ICU). ...