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1.
Neuropsychopharmacology ; 48(1): 54-60, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35995973

RESUMO

Neuronal and synaptic plasticity are widely used terms in the field of psychiatry. However, cellular neurophysiologists have identified two broad classes of plasticity. Hebbian forms of plasticity alter synaptic strength in a synapse specific manner in the same direction of the initial conditioning stimulation. In contrast, homeostatic plasticities act globally over longer time frames in a negative feedback manner to counter network level changes in activity or synaptic strength. Recent evidence suggests that homeostatic plasticity mechanisms can be rapidly engaged, particularly by fast-acting antidepressants such as ketamine to trigger behavioral effects. There is increasing evidence that several neuropsychoactive compounds either directly elicit changes in synaptic activity or indirectly tap into downstream signaling pathways to trigger homeostatic plasticity and subsequent behavioral effects. In this review, we discuss this recent work in the context of a wider paradigm where homeostatic synaptic plasticity mechanisms may provide novel targets for neuropsychiatric treatment advance.


Assuntos
Ketamina , Sinapses , Plasticidade Neuronal/fisiologia , Homeostase/fisiologia , Neurônios , Ketamina/farmacologia
2.
Neuron ; 110(22): 3645-3647, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36395749

RESUMO

In this issue of Neuron, Orr et al.1 demonstrate a detailed molecular cascade that drives presynaptic homeostatic plasticity and enhances presynaptic vesicle fusion in response to reduced postsynaptic activity. Two large presynaptic signaling complexes are central hubs.


Assuntos
Neurônios , Transdução de Sinais , Homeostase/fisiologia , Neurônios/fisiologia , Transdução de Sinais/fisiologia
3.
Physiol Rep ; 10(21): e15495, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36325592

RESUMO

Chronic Kidney Disease (CKD) patients experience an elevated risk for cerebrovascular disease. One factor that may contribute to this heightened risk is an impairment in dynamic cerebral autoregulation, the mechanism by which cerebral vessels modulate cerebral blood flow during fluctuations in arterial pressure. We hypothesized that dynamic cerebral autoregulation would be impaired in CKD. To test this hypothesis, we compared dynamic cerebral autoregulation between CKD patients stages III-IV and matched controls (CON) without CKD. Fifteen patients with CKD and 20 CON participants performed 2, 5-minute bouts of repeated sit-to-stand maneuvers at 0.05 Hz and 0.10 Hz while mean arterial pressure (MAP, via finger photoplethysmography) and middle cerebral artery blood velocity (MCAv, via transcranial Doppler ultrasound) were measured continuously. Cerebral autoregulation was characterized by performing a transfer function analysis (TFA) on the MAP-MCAv relationship to derive coherence, phase, gain, and normalized gain (nGain). We observed no group differences in any of the TFA metrics during the repeated sit-to-stand maneuvers. During the 0.05 Hz maneuver, Coherence: CKD = 0.83 ± 0.13, CON = 0.85 ± 0.12, Phase (radians): CKD = 1.39 ± 0.41, CON = 1.25 ± 0.30, Gain (cm/s/mmHg): CKD = 0.69 ± 0.20, CON = 0.71 ± 0.22, nGain (%/mmHg): CKD = 1.26 ± 0.35, CON = 1.20 ± 0.28, p ≥ 0.24. During the 0.10 Hz maneuver (N = 6 CKD and N = 12 CON), Coherence: CKD = 0.61 ± 0.10, CON = 0.67 ± 0.11, Phase (radians): CKD = 1.43 ± 0.26, CON = 1.30 ± 0.23, Gain (cm/s/mmHg): CKD = 0.75 ± 0.15, CON = 0.84 ± 0.26, nGain (%/mmHg): CKD = 1.50 ± 0.28, CON = 1.29 ± 0.24, p ≥ 0.12. Contrary to our hypothesis, dynamic cerebral autoregulation remains intact in CKD stages III-IV. These findings suggest that other mechanisms likely contribute to the increased cerebrovascular disease burden experienced by this population. Future work should determine if other cerebrovascular regulatory mechanisms are impaired and related to cerebrovascular disease risk in CKD.


Assuntos
Circulação Cerebrovascular , Insuficiência Renal Crônica , Humanos , Velocidade do Fluxo Sanguíneo/fisiologia , Homeostase/fisiologia , Circulação Cerebrovascular/fisiologia , Ultrassonografia Doppler Transcraniana , Artéria Cerebral Média/fisiologia , Pressão Sanguínea/fisiologia
4.
J Cell Sci ; 135(21)2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36349897

RESUMO

The intestine, a rapidly self-renewing organ, is part of the gastrointestinal system. Its major roles are to absorb food-derived nutrients and water, process waste and act as a barrier against potentially harmful substances. Here, we will give a brief overview of the primary functions of the intestine, its structure and the luminal gradients along its length. We will discuss the dynamics of the intestinal epithelium, its turnover, and the maintenance of homeostasis. Finally, we will focus on the characteristics and functions of intestinal mesenchymal and immune cells. In this Cell Science at a Glance article and the accompanying poster, we aim to present the most recent information about gut cell biology and physiology, providing a resource for further exploration.


Assuntos
Mucosa Intestinal , Nutrientes , Homeostase/fisiologia
5.
Int J Mol Sci ; 23(20)2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36293048

RESUMO

Sleep is a fundamental, evolutionarily conserved, plastic behavior that is regulated by circadian and homeostatic mechanisms as well as genetic factors and environmental factors, such as light, humidity, and temperature. Among environmental cues, temperature plays an important role in the regulation of sleep. This review presents an overview of thermoreception in animals and the neural circuits that link this process to sleep. Understanding the influence of temperature on sleep can provide insight into basic physiologic processes that are required for survival and guide strategies to manage sleep disorders.


Assuntos
Ritmo Circadiano , Sono , Animais , Ritmo Circadiano/fisiologia , Temperatura , Sono/fisiologia , Homeostase/fisiologia , Plásticos
6.
Curr Opin Crit Care ; 28(6): 715-724, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36302199

RESUMO

PURPOSE OF REVIEW: This review will highlight the latest research relevant to the clinical care of traumatic brain injury (TBI) patients over the last 2 years while underscoring the implications of these advances in the understanding of diagnosis, treatment, and prognosis of TBI. RECENT FINDINGS: Brain tissue oxygenation monitoring can identify hypoperfusion as an adjunct to intracerebral pressure monitoring. Multiple biomarker assays are now available to help clinicians screen for mild TBI and biomarker elevations correlate with the size of intracranial injury. Beta-blocker exposure following TBI has demonstrated a survival benefit in those with TBI though the mechanism for this remains unknown. The optimal timing for venous thromboembolism prophylaxis for TBI patients is still uncertain. SUMMARY: The current characterization of TBI as mild, moderate, or severe fails to capture the complexity of the disease process and helps little with prognostication. Molecular biomarkers and invasive monitoring devices including brain tissue oxygenation and measures of cerebral autoregulation are being utilized more commonly and can help guide therapy. Extracranial complications following TBI are common and include infection, respiratory failure, coagulopathy, hypercoagulability, and paroxysmal sympathetic hyperactivity.


Assuntos
Lesões Encefálicas Traumáticas , Tromboembolia Venosa , Humanos , Pressão Intracraniana/fisiologia , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/terapia , Encéfalo , Tromboembolia Venosa/tratamento farmacológico , Tromboembolia Venosa/etiologia , Homeostase/fisiologia
7.
Curr Biol ; 32(22): 4957-4966.e5, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36240772

RESUMO

How the homeostatic drive for sleep accumulates over time and is released remains poorly understood. In Drosophila, we previously identified the R5 ellipsoid body (EB) neurons as putative sleep drive neurons1 and recently described a mechanism by which astrocytes signal to these cells to convey sleep need.2 Here, we examine the mechanisms acting downstream of the R5 neurons to promote sleep. EM connectome data demonstrate that R5 neurons project to EPG neurons.3 Broad thermogenetic activation of EPG neurons promotes sleep, whereas inhibiting these cells reduces homeostatic sleep rebound. Perforated patch-clamp recordings reveal that EPG neurons exhibit elevated spontaneous firing following sleep deprivation, which likely depends on an increase in extrinsic excitatory inputs. Our data suggest that cholinergic R5 neurons participate in the homeostatic regulation of sleep, and epistasis experiments indicate that the R5 neurons act upstream of EPG neurons to promote sleep. Finally, we show that the physical and functional connectivity between the R5 and EPG neurons increases with greater sleep need. Importantly, dual patch-clamp recordings demonstrate that activating R5 neurons induces cholinergic-dependent excitatory postsynaptic responses in EPG neurons. Moreover, sleep loss triggers an increase in the amplitude of these responses, as well as in the proportion of EPG neurons that respond. Together, our data support a model whereby sleep drive strengthens the functional connectivity between R5 and EPG neurons, triggering sleep when a sufficient number of EPG neurons are activated. This process could enable the proper timing of the accumulation and release of sleep drive.


Assuntos
Privação do Sono , Sono , Animais , Sono/fisiologia , Homeostase/fisiologia , Neurônios Colinérgicos , Drosophila , Colinérgicos
8.
Trends Neurosci ; 45(12): 942-954, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36272823

RESUMO

The hypothalamus is a brain region that integrates signals from the periphery and the environment to maintain organismal homeostasis. To do so, specialized hypothalamic neuropeptidergic neurons control a range of processes, such as sleep, feeding, the stress response, and hormone release. These processes are altered with age, which can affect longevity and contribute to disease status. Technological advances, such as single-cell RNA sequencing, are upending assumptions about the transcriptional identity of cell types in the hypothalamus and revealing how distinct cell types change with age. In this review, we summarize current knowledge about the contribution of hypothalamic functions to aging. We highlight recent single-cell studies interrogating distinct cell types of the mouse hypothalamus and suggest ways in which single-cell 'omics technologies can be used to further understand the aging hypothalamus and its role in longevity.


Assuntos
Hipotálamo , Neurônios , Animais , Camundongos , Hipotálamo/metabolismo , Neurônios/fisiologia , Homeostase/fisiologia , Envelhecimento , Encéfalo
9.
Physiol Rep ; 10(19): e15484, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36200318

RESUMO

The maternal cardiovascular system, led by renal volume regulatory responses, changes during pregnancy to ensure an adequate circulation for fetal development and growth. Circulatory maladjustment predisposes to hypertensive complications during pregnancy. Mathematical models can be used to gain insight in the gestational cardiovascular physiology. In this study, we developed an accurate, robust, and transparent model for renal autoregulation implemented in an existing circulatory gestational model. This renal autoregulation model aims to maintain steady glomerular pressure by the myogenic response, and glomerular filtration rate by tubuloglomerular feedback, both by inducing a change in the radius, and thus resistance, of the afferent arteriole. The modeled response of renal blood flow and the afferent arteriole following blood pressure increase were compared to published observations in rats. With solely the myogenic response, our model had a maximum deviation of 7% in change in renal blood flow and 7% in renal vascular resistance. When both the myogenic response and tubuloglomerular feedback were concurrently activated, the maximum deviation was 7% in change in renal blood flow and 5% in renal vascular resistance. These results show that our model is able to represent renal autoregulatory behavior comparable to empirical data. Further studies should focus on extending the model with other regulatory mechanisms to understand the hemodynamic changes in healthy and complicated pregnancy.


Assuntos
Rim , Circulação Renal , Animais , Pressão Sanguínea/fisiologia , Taxa de Filtração Glomerular/fisiologia , Hemodinâmica , Homeostase/fisiologia , Ratos , Circulação Renal/fisiologia
10.
BMC Neurol ; 22(1): 364, 2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-36138338

RESUMO

BACKGROUND: Existing data suggest that cerebral autoregulation (CA) varies among different subtypes of ischaemic stroke. CA is globally impaired in patients with small artery occlusion (SAO). However, the factors influencing CA impairment in patients remains to be elucidated. METHODS: Stroke patients with SAO who underwent brain magnetic resonance imaging (MRI) were prospectively studied. Within 7 days after stroke onset, CA was recorded from the middle cerebral artery blood flow velocity and arterial blood pressure was simultaneously measured. Transfer function analysis was used to derive CA parameters, including gain and phase. Clinical characteristics, mean arterial pressure (MAP), biochemical findings, and cerebral small vessel disease (CSVD) markers on MRI were assessed in each patient. Factors associated with CA parameters were investigated. Univariate and multivariate linear regression analyses were conducted to determine the relationship between clinical factors and CA parameters. RESULTS: Sixty-three SAO patients (age, 56.3 ± 9.9 years; 55 men) were enrolled in the study. In the multiple linear regression analysis, after controlling for relevant clinical factors, MAP on admission (ipsilateral OR = 0.99 and contralateral OR = 0.99, both P < 0.005) was a significant independent predictor of bilateral gain. MAP > 105 mmHg on admission (OR = 0.77, P = 0.019) was significantly associated with ipsilateral gain. Diabetes mellitus was a significant predictive factor for bilateral gain (ipsilateral OR = 1.32 and contralateral OR = 1.22, both P < 0.005). No correlations were found between CA parameters and CSVD characteristics. CONCLUSION: In SAO-related ischaemic stroke, patients with MAP > 105 mmHg on admission tended to have better ipsilateral CA. Diabetes mellitus appears to be an independent risk factor for CA impairment in patients with SAO-related stroke. CSVD may not be the main factor affecting bilateral CA in patients with SAO.


Assuntos
Isquemia Encefálica , Doenças de Pequenos Vasos Cerebrais , AVC Isquêmico , Acidente Vascular Cerebral , Idoso , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Doenças de Pequenos Vasos Cerebrais/complicações , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Homeostase/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem
11.
Int J Mol Sci ; 23(18)2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36142548

RESUMO

The importance of gut barrier integrity in intestinal homeostasis and the consequences of its alteration in the etiology of human pathologies have been subjects of exponentially growing interest during the last decade [...].


Assuntos
Mucosa Intestinal , Homeostase/fisiologia , Humanos
13.
Anesth Analg ; 135(4): 734-743, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36108190

RESUMO

In this Pro-Con commentary article, we discuss whether the lower limit of cerebral autoregulation is clinically relevant for anesthesiologists. The central question regarding this issue is whether mean arterial blood pressure below the lower limit of autoregulation is detrimental for the brain. The Pro side argues that continuous monitoring of cerebral autoregulation has revealed an association between going below the lower limit and mortality in the critically ill patient. Conversely, the Con side argues that cerebral autoregulation is only one of various defense mechanisms of the brain that protect against cerebral hypoperfusion, and that cerebral autoregulation may be more important to protect against intracranial hypertension.


Assuntos
Circulação Cerebrovascular , Hipertensão Intracraniana , Anestesiologistas , Encéfalo/fisiologia , Circulação Cerebrovascular/fisiologia , Homeostase/fisiologia , Humanos
14.
Adv Neurobiol ; 28: 45-61, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36066820

RESUMO

Maturation of GABA/Glycine chloride-mediated synaptic inhibitions is crucial for the establishment of a balance between excitation and inhibition. GABA and glycine are excitatory neurotransmitters on immature neurons that exhibit elevated [Cl-]i. Later in development [Cl-]i drops leading to the occurrence of inhibitory synaptic activity. This ontogenic change is closely correlated to a differential expression of two cation-chloride cotransporters that are the Cl- channel K+/Cl- co-transporter type 2 (KCC2) that extrudes Cl- ions and the Na+-K+-2Cl- cotransporter NKCC1 that accumulates Cl- ions. The classical scheme built from studies performed on cortical and hippocampal networks proposes that immature neurons display high [Cl-]i because NKCC1 is overexpressed compared to KCC2 and that the co-transporters ratio reverses in mature neurons, lowering [Cl-]i. In this chapter, we will see that this classical scheme is not true in motoneurons (MNs) and that an early alteration of the chloride homeostasis may be involved in pathological conditions.


Assuntos
Cloretos , Simportadores , Cloretos/metabolismo , Glicina/metabolismo , Homeostase/fisiologia , Humanos , Neurônios Motores/metabolismo , Membro 2 da Família 12 de Carreador de Soluto/metabolismo , Simportadores/metabolismo , Ácido gama-Aminobutírico/metabolismo
15.
Adv Neurobiol ; 28: 87-107, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36066822

RESUMO

Homeostatic plasticity represents a set of compensatory mechanisms that are engaged following a perturbation to some feature of neuronal or network function. Homeostatic mechanisms are most robustly expressed during development, a period that is replete with various perturbations such as increased cell size and the addition/removal of synaptic connections. In this review we look at numerous studies that have advanced our understanding of homeostatic plasticity by taking advantage of the accessibility of developing motoneurons. We discuss the homeostatic regulation of embryonic movements in the living chick embryo and describe the spinal compensatory mechanisms that act to recover these movements (homeostatic intrinsic plasticity) or stabilize synaptic strength (synaptic scaling). We describe the expression and triggering mechanisms of these forms of homeostatic plasticity and thereby gain an understanding of their roles in the motor system. We then illustrate how these findings can be extended to studies of developing motoneurons in other systems including the rodents, zebrafish, and fly. Furthermore, studies in developing drosophila have been critical in identifying some of the molecular signaling cascades and expression mechanisms that underlie homeostatic intrinsic membrane excitability. This powerful model organism has also been used to study a presynaptic form of homeostatic plasticity where increases or decreases in synaptic transmission are associated with compensatory changes in probability of release at the neuromuscular junction. Further, we describe studies that demonstrate homeostatic adjustments of ion channel expression following perturbations to other kinds of ion channels. Finally, we discuss work in xenopus that shows a homeostatic regulation of neurotransmitter phenotype in developing motoneurons following activity perturbations. Together, this work illustrates the importance of developing motoneurons in elucidating the mechanisms and roles of homeostatic plasticity.


Assuntos
Plasticidade Neuronal , Peixe-Zebra , Animais , Embrião de Galinha , Homeostase/fisiologia , Neurônios Motores , Junção Neuromuscular/fisiologia
16.
Adv Neurobiol ; 28: 111-130, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36066823

RESUMO

The mammalian neuromuscular junction (NMJ) is an ideal preparation to study synaptic plasticity. Its simplicity- one input, one postsynaptic target- allows experimental manipulations and mechanistic analyses that are impossible at more complex synapses. Homeostatic synaptic plasticity attempts to maintain normal function in the face of perturbations in activity. At the NMJ, 3 aspects of activity are sensed to trigger 3 distinct mechanisms that contribute to homeostatic plasticity: Block of presynaptic action potentials triggers increased quantal size secondary to increased release of acetylcholine from vesicles. Simultaneous block of pre- and postsynaptic action potentials triggers an increase in the probability of vesicle release. Block of acetylcholine binding to acetylcholine receptors during spontaneous fusion of single vesicles triggers an increase in the number of releasable vesicles as well as increased motoneuron excitability. Understanding how the NMJ responds to perturbations of synaptic activity informs our understanding of its response to diverse neuromuscular diseases.


Assuntos
Acetilcolina , Junção Neuromuscular , Acetilcolina/metabolismo , Animais , Homeostase/fisiologia , Humanos , Mamíferos/metabolismo , Junção Neuromuscular/metabolismo , Plasticidade Neuronal , Sinapses/metabolismo , Transmissão Sináptica/fisiologia
17.
EMBO J ; 41(20): e112383, 2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36097740

RESUMO

Distinct plasticity mechanisms enable neurons to effectively process information also when facing global perturbations in network activity. In this issue of The EMBO Journal, Dubes et al (2022) provide a molecular mechanism whereby individual synapses during periods of chronic inactivity are "tagged" for future strengthening. These results lend further support to the idea that local, nonmultiplicative mechanisms play an important role in homeostatic synaptic plasticity as has been demonstrated for Hebbian-like synaptic plasticity.


Assuntos
Plasticidade Neuronal , Sinapses , Homeostase/fisiologia , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia , Sinapses/fisiologia
18.
J Cereb Blood Flow Metab ; 42(12): 2354-2356, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36113047

RESUMO

Over the past years, a wide range of studies have provided evidence of asymmetry in the response of static and dynamic cerebral autoregulation (CA) during increasing and decreasing pressure challenges. The main message is that CA is stronger during transient increases of arterial blood pressure rather than decreases. Here we do not argue against the presence of CA asymmetry but we seek to raise questions regarding the measurement of the effect and whether this effect needs to be taken into account, especially in clinical settings.


Assuntos
Circulação Cerebrovascular , Ultrassonografia Doppler Transcraniana , Circulação Cerebrovascular/fisiologia , Pressão Sanguínea/fisiologia , Homeostase/fisiologia , Velocidade do Fluxo Sanguíneo/fisiologia
19.
Neuron ; 110(20): 3302-3317.e7, 2022 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-36070750

RESUMO

Homeostatic plasticity (HP) encompasses a suite of compensatory physiological processes that counteract neuronal perturbations, enabling brain resilience. Currently, we lack a complete description of the homeostatic processes that operate within the mammalian brain. Here, we demonstrate that acute, partial AMPAR-specific antagonism induces potentiation of presynaptic neurotransmitter release in adult hippocampus, a form of compensatory plasticity that is consistent with the expression of presynaptic homeostatic plasticity (PHP) documented at peripheral synapses. We show that this compensatory plasticity can be induced within minutes, requires postsynaptic NMDARs, and is expressed via correlated increases in dendritic spine volume, active zone area, and docked vesicle number. Further, simultaneous postsynaptic genetic reduction of GluA1, GluA2, and GluA3 in triple heterozygous knockouts induces potentiation of presynaptic release. Finally, induction of compensatory plasticity at excitatory synapses induces a parallel, NMDAR-dependent potentiation of inhibitory transmission, a cross-modal effect consistent with the anti-epileptic activity of AMPAR-specific antagonists used in humans.


Assuntos
Receptores de N-Metil-D-Aspartato , Sinapses , Humanos , Animais , Sinapses/fisiologia , Receptores de N-Metil-D-Aspartato/metabolismo , Hipocampo/fisiologia , Homeostase/fisiologia , Neurotransmissores/metabolismo , Plasticidade Neuronal/fisiologia , Mamíferos/metabolismo
20.
Paediatr Anaesth ; 32(12): 1320-1329, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36083106

RESUMO

BACKGROUND: Advances in the treatment of pediatric congenital heart disease have increased survival rates. Despite efforts to prevent neurological injury, many patients suffer from impaired neurodevelopmental outcomes. Compromised cerebral autoregulation can increase the risk of brain injury following pediatric cardiac surgery with cardiopulmonary bypass. Monitoring autoregulation and maintaining adequate cerebral blood flow can help prevent neurological injury. AIMS: Our objective was to evaluate autoregulation parameters and to define the optimal blood pressure as well as the lower and upper blood pressure limits of autoregulation. METHODS: Autoregulation was monitored prospectively in 36 infants after cardiopulmonary bypass surgery for congenital heart defects between January and December 2019. Autoregulation indices were calculated by correlating invasive arterial blood pressure, cortical oxygen saturation, and relative tissue hemoglobin levels with near-infrared spectroscopy parameters. RESULTS: The mean patient age was 4.1 ± 2.8 months, and the mean patient weight was 5.2 ± 1.8 kg. Optimal mean arterial pressure could be identified in 88.9% of patients via the hemoglobin volume index and in 91.7% of patients via the cerebral oxygenation index, and a lower limit of autoregulation could be found in 66.7% and 63.9% of patients, respectively. No significant changes in autoregulation indices at the beginning or end of the monitoring period were observed. In 76.5% ± 11.1% and 83.8% ± 9.9% of the 8 and 16 h monitoring times, respectively, the mean blood pressure was inside the range of intact autoregulation (below in 21.5% ± 25.4% and 11.3% ± 16.5% and above in 8.7% ± 10.4% and 6.0% ± 11.0%, respectively). The mean optimal blood pressure was 57.4 ± 8.7 mmHg and 58.2 ± 7.9 mmHg and the mean lower limit of autoregulation was 48.8 ± 8.3 mmHg and 45.5 ± 6.7 mmHg when generated via the hemoglobin volume index and cerebral oxygenation index, respectively. CONCLUSIONS: Postoperative noninvasive autoregulation monitoring after cardiac surgery in children can be reliably and safely performed using the hemoglobin volume index and cerebral oxygenation index and provides robust data. This monitoring can be used to identify individual hemodynamic targets to optimize autoregulation, which differs from those recommended in the literature. Further evaluation of this subject is needed.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Cardiopatias Congênitas , Humanos , Lactente , Pressão Sanguínea/fisiologia , Circulação Cerebrovascular/fisiologia , Cardiopatias Congênitas/cirurgia , Hemoglobinas , Homeostase/fisiologia , Monitorização Intraoperatória , Projetos Piloto
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