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Jovin DG, Katlaps KG, Ellis BK, Dharmaraj B. Neuroprotection against stroke and encephalopathy after cardiac surgery. Interv Med Appl Sci 2019; 11:27-37. [PMID: 32148901 PMCID: PMC7044570 DOI: 10.1556/1646.11.2019.01] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Cerebral ischemia in the perioperative period is a major risk factor for stroke, encephalopathy, and cognitive decline after cardiothoracic surgery. After coronary artery bypass grafting, both stroke and encephalopathy can result in poor patient outcomes and increased mortality. Neuroprotection aims to lessen the severity and occurrence of further injury mediated by stroke and encephalopathy and to aid the recovery of conditions already present. Several pharmacological and non-pharmacological methods of neuroprotection have been investigated in experimental studies and in animal models, and, although some have shown effectiveness in protection of the central nervous system, for most, clinical research is lacking or did not show the expected results. This review summarizes the value and need for neuroprotection in the context of cardiothoracic surgery and examines the use and effectiveness of several agents and methods with an emphasis on clinical trials and clinically relevant neuroprotectants.
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Affiliation(s)
- Daniel G Jovin
- Cardiothoracic Research, Department of Surgery, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, USA
| | - Karl G Katlaps
- Cardiothoracic Research, Department of Surgery, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, USA
| | - Ben K Ellis
- Cardiothoracic Research, Department of Surgery, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, USA
| | - Benita Dharmaraj
- Cardiothoracic Research, Department of Surgery, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA, USA
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2
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Kolevzon A, Bush L, Wang AT, Halpern D, Frank Y, Grodberg D, Rapaport R, Tavassoli T, Chaplin W, Soorya L, Buxbaum JD. A pilot controlled trial of insulin-like growth factor-1 in children with Phelan-McDermid syndrome. Mol Autism 2014; 5:54. [PMID: 25685306 PMCID: PMC4326443 DOI: 10.1186/2040-2392-5-54] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 11/20/2014] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Autism spectrum disorder (ASD) is now understood to have multiple genetic risk genes and one example is SHANK3. SHANK3 deletions and mutations disrupt synaptic function and result in Phelan-McDermid syndrome (PMS), which causes a monogenic form of ASD with a frequency of at least 0.5% of ASD cases. Recent evidence from preclinical studies with mouse and human neuronal models of SHANK3 deficiency suggest that insulin-like growth factor-1 (IGF-1) can reverse synaptic plasticity and motor learning deficits. The objective of this study was to pilot IGF-1 treatment in children with PMS to evaluate safety, tolerability, and efficacy for core deficits of ASD, including social impairment and restricted and repetitive behaviors. METHODS Nine children with PMS aged 5 to 15 were enrolled in a placebo-controlled, double-blind, crossover design study, with 3 months of treatment with IGF-1 and 3 months of placebo in random order, separated by a 4-week wash-out period. RESULTS Compared to the placebo phase, the IGF-1 phase was associated with significant improvement in both social impairment and restrictive behaviors, as measured by the Aberrant Behavior Checklist and the Repetitive Behavior Scale, respectively. IGF-1 was found to be well tolerated and there were no serious adverse events in any participants. CONCLUSIONS This study establishes the feasibility of IGF-1 treatment in PMS and contributes pilot data from the first controlled treatment trial in the syndrome. Results also provide proof of concept to advance knowledge about developing targeted treatments for additional causes of ASD associated with impaired synaptic development and function.
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Affiliation(s)
- Alexander Kolevzon
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, Box 1230, New York, NY 10029 USA ; Friedman Brain Institute, New York, NY USA ; Mindich Child Health Institute, New York, NY USA ; Departments of Psychiatry, New York, NY USA ; Departments of Pediatrics, New York, NY USA ; Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Lauren Bush
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, Box 1230, New York, NY 10029 USA ; Departments of Psychiatry, New York, NY USA ; Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - A Ting Wang
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, Box 1230, New York, NY 10029 USA ; Friedman Brain Institute, New York, NY USA ; Departments of Psychiatry, New York, NY USA ; Departments of Neuroscience, New York, NY USA ; Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Danielle Halpern
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, Box 1230, New York, NY 10029 USA ; Departments of Psychiatry, New York, NY USA ; Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Yitzchak Frank
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, Box 1230, New York, NY 10029 USA ; Departments of Psychiatry, New York, NY USA ; Departments of Pediatrics, New York, NY USA ; Departments of Neurology, New York, NY USA ; Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - David Grodberg
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, Box 1230, New York, NY 10029 USA ; Departments of Psychiatry, New York, NY USA ; Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Robert Rapaport
- Departments of Pediatrics, New York, NY USA ; Departments of Endocrinology and Diabetes, New York, NY USA ; Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Teresa Tavassoli
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, Box 1230, New York, NY 10029 USA ; Departments of Psychiatry, New York, NY USA ; Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - William Chaplin
- Department of Psychology, St John's University, New York, NY USA
| | - Latha Soorya
- Department of Psychiatry, Rush University Medical Center, Chicago, IL USA
| | - Joseph D Buxbaum
- Seaver Autism Center for Research and Treatment, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, Box 1230, New York, NY 10029 USA ; Friedman Brain Institute, New York, NY USA ; Mindich Child Health Institute, New York, NY USA ; Departments of Psychiatry, New York, NY USA ; Departments of Neuroscience, New York, NY USA ; Departments of Genetics and Genomic Sciences, New York, NY USA ; Icahn School of Medicine at Mount Sinai, New York, NY USA
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Stretti F, Gotti M, Pifferi S, Brandi G, Annoni F, Stocchetti N. Body temperature affects cerebral hemodynamics in acutely brain injured patients: an observational transcranial color-coded duplex sonography study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2014; 18:552. [PMID: 25311035 PMCID: PMC4213544 DOI: 10.1186/s13054-014-0552-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 09/23/2014] [Indexed: 11/18/2022]
Abstract
Introduction Temperature changes are common in patients in a neurosurgical intensive care unit (NICU): fever is frequent among severe cases and hypothermia is used after cardiac arrest and is currently being tested in clinical trials to lower intracranial pressure (ICP). This study investigated cerebral hemodynamics when body temperature varies in acute brain injured patients. Methods We enrolled 26 patients, 14 with acute brain injury who developed fever and were given antipyretic therapy (defervescence group) and 12 who underwent an intracranial neurosurgical procedure and developed hypothermia in the operating room; once admitted to the NICU, still under anesthesia, they were re-warmed before waking (re-warming group). We measured cerebral blood flow velocity (CBF-V) and pulsatility index (PI) at the middle cerebral artery using transcranial color-coded duplex sonography (TCCDS). Results In the defervescence group mean CBF-V decreased from 75 ± 26 (95% CI 65 to 85) to 70 ± 22 cm/s (95% CI 61 to 79) (P = 0.04); the PI also fell, from 1.36 ± 0.33 (95% CI 1.23 to 1.50) to 1.16 ± 0.26 (95% CI 1.05 to 1.26) (P = 0.0005). In the subset of patients with ICP monitoring, ICP dropped from 16 ± 8 to 12 ± 6 mmHg (P = 0.003). In the re-warming group mean CBF-V increased from 36 ± 10 (95% CI 31 to 41) to 39 ± 13 (95% CI 33 to 45) cm/s (P = 0.04); the PI rose from 0.98 ± 0.14 (95% CI 0.91 to 1.04) to 1.09 ± 0.22 (95% CI 0.98 to 1.19) (P = 0.02). Conclusions Body temperature affects cerebral hemodynamics as evaluated by TCCDS; when temperature rises, CBF-V increases in parallel, and viceversa when temperature decreases. When cerebral compliance is reduced and compensation mechanisms are exhausted, even modest temperature changes can greatly affect ICP.
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Tan CO, Hamner JW, Taylor JA. The role of myogenic mechanisms in human cerebrovascular regulation. J Physiol 2013; 591:5095-105. [PMID: 23959681 DOI: 10.1113/jphysiol.2013.259747] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Although myogenic mechanisms have been hypothesized to play a role in cerebrovascular regulation, previous data from both animals and humans have not provided an unequivocal answer. However, cerebral autoregulation is explicitly non-linear and most prior work relied on simple linear approaches for assessment, potentially missing important changes in autoregulatory characteristics. Therefore, we examined cerebral blood flow responses to augmented arterial pressure oscillations with and without calcium channel blockade (nicardipine) during blood pressure fluctuations (oscillatory lower body negative pressure, OLBNP) across a range of frequencies in 16 healthy subjects. Autoregulation was characterized via a robust non-linear method (projection pursuit regression, PPR). Blockade resulted in significant tachycardia, a modest but significant elevation in mean arterial pressure, and reductions in mean cerebral blood flow and end-tidal CO2 during OLBNP. The reductions in flow were directly related to the reductions in CO2 (r = 0.57). While linear cross-spectral analysis showed that the relationship between pressure-flow fluctuations was preserved after blockade, PPR showed that blockade significantly altered the non-linearity between pressure and flow, particularly at the slowest fluctuations. At 0.03 Hz, blockade reduced the range of pressure fluctuations that can be buffered (7.5 ± 1.0 vs. 3.7 ± 0.8 mmHg) while increasing the autoregulatory slope (0.10 ± 0.05 vs. 0.24 ± 0.08 cm s(-1) mmHg(-1)). Furthermore, the same rate of change in pressure elicited a change in flow more than twice as large as at baseline. Thus, our results show that myogenic mechanisms play a significant role in cerebrovascular regulation but this may not be appreciated without adequately characterizing the non-linearities inherent in cerebrovascular regulation.
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Affiliation(s)
- Can Ozan Tan
- C. O. Tan: Cardiovascular Research Laboratory, SW052, Spaulding Hospital Cambridge, Cambridge, MA 02138, USA.
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5
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Schatlo B, Gläsker S, Zauner A, Thompson BG, Oldfield EH, Pluta RM. Continuous neuromonitoring using transcranial Doppler reflects blood flow during carbon dioxide challenge in primates with global cerebral ischemia. Neurosurgery 2009; 64:1148-54; discussion 1154. [PMID: 19487895 DOI: 10.1227/01.neu.0000343542.61238.df] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE At present, there is no consensus on the optimal monitoring method for cerebral blood flow (CBF) in neurointensive care patients. The aim of the present study was to investigate whether continuous transcranial Doppler (TCD) monitoring with modulation of partial pressure of CO2 reflects CBF changes. This hypothesis was tested in 2 pathological settings in which cerebral ischemia can be imminent: after an episode of cerebral ischemia and during vasospasm after subarachnoid hemorrhage. METHODS Sixteen cynomolgus monkeys were divided into 3 groups: 1) chemoregulation in control animals to assess the physiological range of CBF regulation, 2) chemoregulation during vasospasm after subarachnoid hemorrhage, and 3) chemoregulation after transient cerebral ischemia. We surgically placed a thermal CBF probe over the cortex perfused by the right middle cerebral artery. Corresponding TCD values were acquired simultaneously while partial pressure of CO2 was changed within a range of 25 to 65 mm Hg (chemoregulation). A correlation coefficient of CBF with TCD values of greater than r equals 0.8 was considered clinically relevant. RESULTS CBF and CBF velocity correlated strongly after cerebral ischemia (r = 0.83, P < 0.001). Correlations were poor in chemoregulation controls (r = 0.2) and in the vasospasm group (r = 0.55). CONCLUSION The present study provides experimental support that, in clearly defined conditions, continuous TCD monitoring combined with chemoregulation testing may provide an estimate of CBF in the early postischemic period.
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Affiliation(s)
- Bawarjan Schatlo
- Surgical Neurology Branch, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA
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Hernandez G, Peña H, Cornejo R, Rovegno M, Retamal J, Navarro JL, Aranguiz I, Castro R, Bruhn A. Impact of emergency intubation on central venous oxygen saturation in critically ill patients: a multicenter observational study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2009; 13:R63. [PMID: 19413905 PMCID: PMC2717418 DOI: 10.1186/cc7802] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Revised: 04/17/2009] [Accepted: 05/04/2009] [Indexed: 01/20/2023]
Abstract
INTRODUCTION Central venous oxygen saturation (ScvO2) has emerged as an important resuscitation goal for critically ill patients. Nevertheless, growing concerns about its limitations as a perfusion parameter have been expressed recently, including the uncommon finding of low ScvO2 values in patients in the intensive care unit (ICU). Emergency intubation may induce strong and eventually divergent effects on the physiologic determinants of oxygen transport (DO2) and oxygen consumption (VO2) and, thus, on ScvO2. Therefore, we conducted a study to determine the impact of emergency intubation on ScvO2. METHODS In this prospective multicenter observational study, we included 103 septic and non-septic patients with a central venous catheter in place and in whom emergency intubation was required. A common intubation protocol was used and we evaluated several parameters including ScvO2 before and 15 minutes after emergency intubation. Statistical analysis included chi-square test and t test. RESULTS ScvO2 increased from 61.8 +/- 12.6% to 68.9 +/- 12.2%, with no difference between septic and non-septic patients. ScvO2 increased in 84 patients (81.6%) without correlation to changes in arterial oxygen saturation (SaO2). Seventy eight (75.7%) patients were intubated with ScvO2 less than 70% and 21 (26.9%) normalized the parameter after the intervention. Only patients with pre-intubation ScvO2 more than 70% failed to increase the parameter after intubation. CONCLUSIONS ScvO2 increases significantly in response to emergency intubation in the majority of septic and non-septic patients. When interpreting ScvO2 during early resuscitation, it is crucial to consider whether the patient has been recently intubated or is spontaneously breathing.
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Affiliation(s)
- Glenn Hernandez
- Departamento de Medicina Intensiva, Pontificia Universidad Católica de Chile, Marcoleta 367, Santiago, Chile.
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Kotani Y, Shimazawa M, Yoshimura S, Iwama T, Hara H. The experimental and clinical pharmacology of propofol, an anesthetic agent with neuroprotective properties. CNS Neurosci Ther 2008; 14:95-106. [PMID: 18482023 PMCID: PMC6494023 DOI: 10.1111/j.1527-3458.2008.00043.x] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Propofol (2,6-diisopropylphenol) is a versatile, short-acting, intravenous (i.v.) sedative-hypnotic agent initially marketed as an anesthetic, and now also widely used for the sedation of patients in the intensive care unit (ICU). At the room temperature propofol is an oil and is insoluble in water. It has a remarkable safety profile. Its most common side effects are dose-dependent hypotension and cardiorespiratory depression. Propofol is a global central nervous system (CNS) depressant. It activates gamma-aminobutyric acid (GABA A) receptors directly, inhibits the N-methyl-d-aspartate (NMDA) receptor and modulates calcium influx through slow calcium-ion channels. Furthermore, at doses that do not produce sedation, propofol has an anxiolytic effect. It has also immunomodulatory activity, and may, therefore, diminish the systemic inflammatory response believed to be responsible for organ dysfunction. Propofol has been reported to have neuroprotective effects. It reduces cerebral blood flow and intracranial pressure (ICP), is a potent antioxidant, and has anti-inflammatory properties. Laboratory investigations revealed that it might also protect brain from ischemic injury. Propofol formulations contain either disodium edetate (EDTA) or sodium metabisulfite, which have antibacterial and antifungal properties. EDTA is also a chelator of divalent ions such as calcium, magnesium, and zinc. Recently, EDTA has been reported to exert a neuroprotective effect itself by chelating surplus intracerebral zinc in an ischemia model. This article reviews the neuroprotective effects of propofol and its mechanism of action.
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Affiliation(s)
- Yoshinori Kotani
- Department of Biofunctional Evaluation, Molecular Pharmacology, Gifu Pharmaceutical University, Gifu 502-8585, Japan
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Abstract
This review focuses on the effects of cardiac surgery and cardiopulmonary bypass on the brain, with special emphasis on the results of recently conducted studies. The incidence of postoperative neurological and neuropsychological deficits and risk factors for cerebral injury are reviewed. The relationships between cerebral embolic load, release of biochemical markers of brain injury and cognitive dysfunction after cardiac surgery are also reviewed. Finally, recently gained information on the management of cardiopulmonary bypass is discussed, along with the results of recent pharmacological neuroprotective trials in patients undergoing cardiac surgery.
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Affiliation(s)
- S E Ricksten
- Department of Cardiothoracic Anesthesia and Intensive Care, Sahlgrenska University, Göteborg, Sweden.
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9
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Abstract
Interventions in the intensive care unit often require that the patient be sedated. Propofol is a widely used, potent sedative agent that is popular in critical care and operating room settings. In addition to its sedative qualities, propofol has neurovascular, neuroprotective, and electroencephalographical effects that are salutory in the patient in neurocritical care. However, the 15-year experience with this agent has not been entirely unbesmirched by controversy: propofol also has important adverse effects that must be carefully considered. This article discusses and reviews the pharmacology of propofol, with specific emphasis on its use as a sedative in the neuro-intensive care unit. A detailed explanation of central nervous system and cardiovascular mechanisms is presented. Additionally, the article reviews the literature specifically pertaining to neurocritical care use of propofol.
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Affiliation(s)
- Michael P Hutchens
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR 97239, USA.
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Hu X, Nenov V, Glenn TC, Steiner LA, Czosnyka M, Bergsneider M, Martin N. Nonlinear Analysis of Cerebral Hemodynamic and Intracranial Pressure Signals for Characterization of Autoregulation. IEEE Trans Biomed Eng 2006; 53:195-209. [PMID: 16485748 DOI: 10.1109/tbme.2005.862546] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The objective of this study was to determine whether or not the underlying physiological systems that generates spontaneous arterial blood pressure (ABP), cerebral blood flow velocity (CBFV), and intracranial pressure signals could be adequately approximated as a linear stochastic process. Furthermore, a new measure (C) capable of capturing the degree of nonlinear dependency between two ABP and CBFV signals (including a time-varying situation) was proposed for quantifying the degree of cerebral blood flow autoregulation. A surrogate data test of fifteen ABP, CBFV, and intracranial pressure (ICP) segments was conducted for detecting whether there exists a statistically significant deviation from the null hypothesis of linear signals. The extension of the established block computation method of C measure to an adaptive one was achieved. This new algorithm was then applied to study the C evolution using brain injury patients data from a hyperventilation study and two propofol studies. Nonlinearity has not been detected for all the fifteen recordings, neither has nonlinear dependency between CBFV and ABP. However, their presences in some of the signal segments justified the adoption of a nonlinear measure of dependency capable of characterizing both linear and nonlinear correlations for inferring autoregulation status. C measure started to decrease with the introduction of hypocapnia state indicating that hyperventilation may reduce the dependency of CBFV on ABP fluctuations. On the other hand, complex patterns of C measure evolution were observed among 14 cases of propofol data indicating a nontrivial effect of propofol on the dependency of CBFV on ABP.
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Affiliation(s)
- Xiao Hu
- Brain Monitoring and Modeling Laboratory, Division of Neurosurgery, University of California, Los Angeles 90034, USA.
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11
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Han TH, Lee JH, Kwak IS, Kil HY, Han KW, Kim KM. The relationship between bispectral index and targeted propofol concentration is biphasic in patients with major burns. Acta Anaesthesiol Scand 2005; 49:85-91. [PMID: 15675988 DOI: 10.1111/j.1399-6576.2004.00532.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Many pathophysiologic alterations in major burns can cause changes in the distribution of, and perhaps response to, drugs commonly used in anesthesia practice. This study was conducted to assess changes in bispectral index (BIS) caused by increasing the target propofol effect-site concentration during a target-controlled infusion (TCI) in major burns. METHODS Eighteen patients, ASA physical status 2 or 3, aged from 20 to 55 years old, weighing 50-70 kg, with major burns, scheduled for elective early escharectomy less than a week after injury were recruited. A further 18 ASA physical status class 1 or 2, non-burns, age, sex- and weight-matched adult patients scheduled for elective surgery under general anesthesia were recruited as controls. During anesthesia induction, target propofol effect-site concentrations were increased by increments of 0.5 microg ml(-1) up to 4.5 microg ml(-1). The BIS responses to each target concentration using TCI were compared in both groups. RESULTS In the burns group, significantly greater BIS values relating to increasing propofol TCI were noted at deeper anesthesia when compared with controls; at > or =3.5 microg ml(-1); mean BIS remained at a plateau of about 50. Patients with burns had higher cardiac indices, and lower hemoglobin and albumin concentrations than the controls. They consumed more vecuronium to maintain the same degree of neuromuscular blockade than the controls. CONCLUSIONS In major burns, the final biphasic BIS responses appeared to be determined by numerous other variables such as BIS algorithm, TCI performance, and altered propofol pharmacokinetics and pharmacodynamics. According to our results the importance of an individually tailored approach, including careful anesthetic titration, based upon the patient's clinical condition and responses can not be overemphasized.
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Affiliation(s)
- T-H Han
- Department of Anesthesiology and Pain Medicine, Hangang Sacred Heart Hospital, Hallym University, College of Medicine, Seoul, Korea.
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Lagace A, Karsli C, Luginbuehl I, Bissonnette B. The effect of remifentanil on cerebral blood flow velocity in children anesthetized with propofol. Paediatr Anaesth 2004; 14:861-5. [PMID: 15385016 DOI: 10.1111/j.1460-9592.2004.01323.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Cerebrovascular stability and rapid anesthetic emergence are desirable features of a neuroanesthetic regimen. In this randomized crossover study the effect of a low-dose remifentanil infusion on cerebral blood flow velocity (CBFV) in children anesthetized with propofol was evaluated. METHODS Twenty healthy children aged 1-6 years undergoing urological surgery were enrolled. Following face mask induction with sevoflurane, anesthesia was maintained with a standardized propofol infusion. Rocuronium was used to facilitate tracheal intubation and normothermia, and normocapnia were maintained. All children received a caudal epidural block, and a transcranial Doppler probe was placed to measure middle cerebral artery blood flow velocity (Vmca). Each patient received a remifentanil regimen of 0.5 microg x kg(-1) followed by 0.2 microg x kg(-1) x min(-1) in a predetermined order of remifentanil + propofol or propofol alone. Vmca, mean arterial pressure (MAP) and heart rate (HR) were recorded simultaneously at equilibrium with and without remifentanil. RESULTS The combination of remifentanil and propofol caused an 8.1% decrease in MAP (P = 0.0005) and an 11.8% decrease in HR (P < 0.0001) compared with propofol alone. Vmca was not different between the two groups (P = 0.4041). CONCLUSION The addition of remifentanil to propofol anesthesia in children causes a reduction in MAP and HR without affecting CBFV. This may imply that cerebral blood pressure autoregulation is preserved in children under propofol and remifentanil anesthesia.
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Affiliation(s)
- Annie Lagace
- Department of Anaesthesia, University of Toronto, Toronto, Ontario, Canada
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Steiner LA, Johnston AJ, Chatfield DA, Czosnyka M, Coleman MR, Coles JP, Gupta AK, Pickard JD, Menon DK. The effects of large-dose propofol on cerebrovascular pressure autoregulation in head-injured patients. Anesth Analg 2003; 97:572-576. [PMID: 12873955 DOI: 10.1213/01.ane.0000070234.17226.b0] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
UNLABELLED In healthy individuals, cerebrovascular pressure autoregulation is preserved or even improved when propofol is infused. We examined the effect of an increase in propofol plasma concentration on pressure autoregulation in 10 head-injured patients. Using target-controlled infusions, the static rate of autoregulation was determined at a moderate (2.3 +/- 0.4 microg/mL) and a large (4.3 +/- 0.04 microg/mL) plasma target concentration of propofol. Using norepinephrine to control cerebral perfusion pressure, transcranial Doppler measurements from the middle cerebral artery were made at a cerebral perfusion pressure of 70 and 85 mm Hg at each propofol concentration. Middle cerebral artery flow velocities at the large propofol concentration were significantly lower than at the moderate concentration, without any concurrent increase in arterio-jugular difference in oxygen content, a finding compatible with maintained flow-metabolism coupling. Despite this, static rate of autoregulation decreased significantly from 54% +/- 36% to 28% +/- 35% (P = 0.029). Our data suggest that after head injury, the cerebrovascular effects of propofol are different from those observed in healthy individuals. We propose that large doses of propofol should be used cautiously in head-injured patients, because there is the potential to increase the injured brain's vulnerability to secondary insults. IMPLICATIONS Propofol is used for sedation and control of intracranial pressure in head-injured patients. In contrast to previous data from healthy individuals, we show a deterioration of cerebrovascular pressure autoregulation with fast propofol infusion rates after head injury. Large propofol doses may increase the injured brain's vulnerability to secondary insults.
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Affiliation(s)
- Luzius A Steiner
- *Academic Neurosurgery, †University Department of Anaesthesia, and ‡Wolfson Brain Imaging Centre, Addenbrooke's Hospital, Cambridge, United Kingdom
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Abstract
Cerebral pressure autoregulation, a sensitive homeostatic mechanism important for the control of cerebral blood flow, is impaired by disease pathology and some drugs commonly used during anaesthesia. Therefore, the assessment of cerebral pressure autoregulation can help optimize cerebral blood flow in patients who have suffered neurological insults. In this article, we outline the means available for testing cerebral pressure autoregulation, thus allowing the reader to decide on the best strategy to adopt in their particular operating theatre and intensive care setting.
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Affiliation(s)
- Frank A Rasulo
- Department of Anaesthesia, Addenbrookes Hospital, Cambridge CB2 2QQ, UK
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15
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Tobias JD. Propofol: Effects on the Central Nervous System. J Intensive Care Med 2000. [DOI: 10.1046/j.1525-1489.2000.00237.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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