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Dynamic cerebral autoregulation during step-wise increases in blood pressure during anaesthesia: A nonrandomised interventional trial. Eur J Anaesthesiol 2023; 40:407-417. [PMID: 36655712 PMCID: PMC10155696 DOI: 10.1097/eja.0000000000001798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Classically, cerebral autoregulation (CA) entails cerebral blood flow (CBF) remaining constant by cerebrovascular tone adapting to fluctuations in mean arterial pressure (MAP) between ∼60 and ∼150 mmHg. However, this is not an on-off mechanism; previous work has suggested that vasomotor tone is proportionally related to CA function. During propofol-based anaesthesia, there is cerebrovascular vasoconstriction, and static CA remains intact. Sevoflurane-based anaesthesia induces cerebral vasodilation and attenuates CA dose-dependently. It is unclear how this translates to dynamic CA across a range of blood pressures in the autoregulatory range. OBJECTIVE The aim of this study was to quantify the effect of step-wise increases in MAP between 60 and 100 mmHg, using phenylephrine, on dynamic CA during propofol- and sevoflurane-based anaesthesia. DESIGN A nonrandomised interventional trial. SETTING Single centre enrolment started on 11 January 2019 and ended on 23 September 2019. PATIENTS We studied American Society of Anesthesiologists (ASA) I/II patients undergoing noncardiothoracic, nonneurosurgical and nonlaparoscopic surgery under general anaesthesia. INTERVENTION In this study, cerebrovascular tone was manipulated in the autoregulatory range by increasing MAP step-wise using phenylephrine in patients receiving either propofol- or sevoflurane-based anaesthesia. MAP and mean middle cerebral artery blood velocity (MCA Vmean ) were measured in ASA I and II patients, anaesthetised with either propofol ( n = 26) or sevoflurane ( n = 28), during 10 mmHg step-wise increments of MAP between 60 and 100 mmHg. Static CA was determined by plotting 2-min averaged MCA Vmean versus MAP. Dynamic CA was determined using transfer function analysis and expressed as the phase lead (°) between MAP and MCA Vmean oscillations, created with positive pressure ventilation with a frequency of 6 min -1 . MAIN OUTCOMES The primary outcome of this study was the response of dynamic CA during step-wise increases in MAP during propofol- and sevoflurane-based anaesthesia. RESULTS MAP levels achieved per step-wise increments were comparable between anaesthesia regiment (63 ± 3, 72 ± 2, 80 ± 2, 90 ± 2, 100 ± 3 mmHg, and 61 ± 4, 71 ± 2, 80 ± 2, 89 ± 2, 98 ± 4 mmHg for propofol and sevoflurane, respectively). MCA Vmean increased more during step-wise MAP increments for sevoflurane compared to propofol ( P ≤0.001). Dynamic CA improved during propofol (0.73° mmHg -1 , 95% CI 0.51 to 0.95; P ≤ 0.001)) and less pronounced during sevoflurane-based anaesthesia (0.21° mmHg -1 (95% CI 0.01 to 0.42, P = 0.04). CONCLUSIONS During general anaesthesia, dynamic CA is dependent on MAP, also within the autoregulatory range. This phenomenon was more pronounced during propofol anaesthesia than during sevoflurane. TRIAL REGISTRATION NCT03816072 ( https://clinicaltrials.gov/ct2/show/NCT03816072 ).
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Vedaei F, Alizadeh M, Tantawi M, Romo V, Mohamed FB, Wu C. Vascular and neuronal effects of general anesthesia on the brain: An fMRI study. J Neuroimaging 2023; 33:109-120. [PMID: 36097249 DOI: 10.1111/jon.13049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/30/2022] [Accepted: 08/30/2022] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND AND PURPOSE A number of functional magnetic resonance imaging (fMRI) studies rely on application of anesthetic agents during scanning that can modulate and complicate interpretation of the measured hemodynamic blood oxygenation level-dependent (BOLD) response. The purpose of the present study was to investigate the effect of general anesthesia on two main components of BOLD signal including neuronal activity and vascular response. METHODS Breath-holding (BH) fMRI was conducted in wakefulness and under anesthesia states in 9 patients with drug-resistant epilepsy who needed to get scanned under anesthesia during laser interstitial thermal therapy. BOLD and BOLD cerebrovascular reactivity (BOLD-CVR) maps were compared using t-test between two states to assess the effect of anesthesia on neuronal activity and vascular factors (p < .05). RESULTS Overall, our findings revealed an increase in BOLD-CVR and decrease in BOLD response under anesthesia in several brain regions. The results proposed that the modulatory mechanism of anesthetics on neuronal and vascular components of BOLD signal may work in different ways. CONCLUSION This experiment for the first human study showed that anesthesia may play an important role in dissociation between neuronal and vascular responses contributed to hemodynamic BOLD signal using BH fMRI imaging that may assist the implication of general anesthesia and interpretation of outcomes in clinical setting.
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Affiliation(s)
- Faezeh Vedaei
- Jefferson Integrated Magnetic Resonance Imaging Center, Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Mahdi Alizadeh
- Jefferson Integrated Magnetic Resonance Imaging Center, Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.,Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Mohamed Tantawi
- Jefferson Integrated Magnetic Resonance Imaging Center, Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Victor Romo
- Department of Anesthesiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Feroze B Mohamed
- Jefferson Integrated Magnetic Resonance Imaging Center, Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Chengyuan Wu
- Jefferson Integrated Magnetic Resonance Imaging Center, Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.,Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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Comparison of cerebral oxygen desaturation events between children under general anesthesia and chloral hydrate sedation - a randomized controlled trial. BMC Pediatr 2022; 22:720. [PMID: 36529729 PMCID: PMC9762051 DOI: 10.1186/s12887-022-03739-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 11/08/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND During pediatric general anesthesia (GA) and sedation, clinicians aim to maintain physiological parameters within normal ranges. Accordingly, regional cerebral oxygen saturation (rScO2) should not drop below preintervention baselines. Our study compared rScO2 desaturation events in children undergoing GA or chloral hydrate sedation (CHS). METHODS Ninety-two children undergoing long auditory assessments were randomly assigned to two study arms: CHS (n = 40) and GA (n = 52). Data of 81 children (mean age 13.8 months, range 1-36 months) were analyzed. In the GA group, we followed a predefined 10 N concept (no fear, no pain, normovolemia, normotension, normocardia, normoxemia, normocapnia, normonatremia, normoglycemia, and normothermia). In this group, ENT surgeons performed minor interventions in 29 patients based on intraprocedural microscopic ear examinations. In the CHS group, recommendations for monitoring and treatment of children undergoing moderate sedation were met. Furthermore, children received a double-barreled nasal oxygen cannula to measure end-tidal carbon dioxide (etCO2) and allow oxygen administration. Chloral hydrate was administered in the parent's presence. Children had no intravenous access which is an advantage of sedation techniques. In both groups, recommendations for fasting were followed and an experienced anesthesiologist was present during the entire procedure. Adverse event (AE) was a decline in cerebral oxygenation to below 50% or below 20% from the baseline for ≥1 min. The primary endpoint was the number of children with AE across the study arms. Secondary variables were: fraction of inspired oxygen (FIO2), oxygen saturation (SpO2), etCO2, systolic and mean blood pressure (BP), and heart rate (HR); these variables were analyzed for their association with drop in rScO2 to below baseline (%drop_rScO2). RESULTS The incidence of AE across groups was not different. The analysis of secondary endpoints showed evidence that %drop_rScO2 is more dependent on HR and FIO2 than on BP and etCO2. CONCLUSIONS This study highlights the strong association between HR and rScO2 in children aged < 3 years, whereas previous studies had primarily discussed the role of BP and etCO2. Prompt HR correction may result in shorter periods of cerebral desaturation. TRIAL REGISTRATION The study was retrospectively registered with the German Clinical Trials Registry (DRKS00024362, 04/02/2021).
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Dos Santos e Santos C, dos S. e Santos G, Araujo Tuma Santos C. Anesthetic Management for Resection of a Cerebellar Hemangioblastoma Leading to Brainstem Compression in a Patient With Von Hippel-Lindau Disease. Cureus 2021; 13:e20608. [PMID: 35103184 PMCID: PMC8782097 DOI: 10.7759/cureus.20608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2021] [Indexed: 11/23/2022] Open
Abstract
Von Hippel-Lindau (VHL) disease is a complex genetic syndrome characterized by multisystemic vascular neoplastic disorder. The affected population tends to develop tumors mainly involving the central nervous system, adrenal glands, pancreas, and kidneys. We describe anesthetic management for the resection of a cerebellar mass compressing the brainstem in a recently diagnosed 25-year-old female patient with a history of von Hippel-Lindau (VHL) syndrome. An uneventful occipital craniectomy for cerebellar tumor resection was performed under total intravenous anesthesia, without complications. The patient was discharged home on postoperative day five. This case depicts a situation in which a brainstem compressing lesion needs to be addressed urgently, and the pharmacological neuroprotective technique utilized for this procedure.
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Propofol/Remifentanil Anesthesia Might Not Alter the Middle Cerebral Artery Diameter by Digital Subtraction Angiography. Neurocrit Care 2020; 31:338-345. [PMID: 30877554 DOI: 10.1007/s12028-019-00699-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Transcranial Doppler (TCD) of the middle cerebral artery (MCA) enables the measurement of the mean blood velocity (MCAVm) and the estimation of the cerebral blood flow (CBF), provided that no significant changes occur in the MCA diameter (MCADiam). Previous studies described a decrease in the MCAVm associated with the induction of total intravenous anesthesia (TIVA) by propofol and remifentanil. This decrease in blood velocity might be interpreted as a decrease in the CBF only where the MCADiam is not modified across TCD examinations. METHODS In this observational study, we measured the MCADiam of 24 subjects (almost exclusively females) on digital subtraction angiography under awake and TIVA conditions. RESULTS Across the two phases, we observed a decrease in the mean arterial blood pressure (from 84 ± 9 to 71 ± 6 mmHg; p < 0.001) and heart rate (76 ± 10 vs. 65 ± 8 beats/min; p < 0.001), and a concomitant decrease in the MCAVm (61 vs. 42 cm/s; p < 0.001). In contrast, the MCADiam did not vary in association with TIVA (2.3 ± 0.2 vs. 2.3 ± 0.2 mm; p = 0.52). CONCLUSIONS Those results suggested that in this population, no significant changes in the MCADiam are associated with TIVA.
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Internal Carotid Artery Blood Flow Response to Anesthesia, Pneumoperitoneum, and Head-up Tilt during Laparoscopic Cholecystectomy. Anesthesiology 2019; 131:512-520. [DOI: 10.1097/aln.0000000000002838] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Abstract
Editor’s Perspective
What We Already Know about This Topic
What This Article Tells Us That Is New
Background
Little is known about how implementation of pneumoperitoneum and head-up tilt position contributes to general anesthesia-induced decrease in cerebral blood flow in humans. We investigated this question in patients undergoing laparoscopic cholecystectomy, hypothesizing that cardiorespiratory changes during this procedure would reduce cerebral perfusion.
Methods
In a nonrandomized, observational study of 16 patients (American Society of Anesthesiologists physical status I or II) undergoing laparoscopic cholecystectomy, internal carotid artery blood velocity was measured by Doppler ultrasound at four time points: awake, after anesthesia induction, after induction of pneumoperitoneum, and after head-up tilt. Vessel diameter was obtained each time, and internal carotid artery blood flow, the main outcome variable, was calculated. The authors recorded pulse contour estimated mean arterial blood pressure (MAP), heart rate (HR), stroke volume (SV) index, cardiac index, end-tidal carbon dioxide (ETco2), bispectral index, and ventilator settings. Results are medians (95% CI).
Results
Internal carotid artery blood flow decreased upon anesthesia induction from 350 ml/min (273 to 410) to 213 ml/min (175 to 249; −37%, P < 0.001), and tended to decrease further with pneumoperitoneum (178 ml/min [127 to 208], −15%, P = 0.026). Tilt induced no further change (171 ml/min [134 to 205]). ETco2 and bispectral index were unchanged after induction. MAP decreased with anesthesia, from 102 (91 to 108) to 72 (65 to 76) mmHg, and then remained unchanged (Pneumoperitoneum: 70 [63 to 75]; Tilt: 74 [66 to 78]). Cardiac index decreased with anesthesia and with pneumoperitoneum (overall from 3.2 [2.7 to 3.5] to 2.3 [1.9 to 2.5] l · min−1 · m−2); tilt induced no further change (2.1 [1.8 to 2.3]). Multiple regression analysis attributed the fall in internal carotid artery blood flow to reduced cardiac index (both HR and SV index contributing) and MAP (P < 0.001). Vessel diameter also declined (P < 0.01).
Conclusions
During laparoscopic cholecystectomy, internal carotid artery blood flow declined with anesthesia and with pneumoperitoneum, in close association with reductions in cardiac index and MAP. Head-up tilt caused no further reduction. Cardiac output independently affects human cerebral blood flow.
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Hirata A, Kasahara M, Matsuura N, Ichinohe T. Remifentanil decreases oral tissue blood flow while maintaining internal carotid artery blood flow during sevoflurane anesthesia in rabbits. J Vet Med Sci 2017; 80:354-360. [PMID: 29269709 PMCID: PMC5836777 DOI: 10.1292/jvms.17-0319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to investigate the effect of remifentanil infusion on oral
tissue blood flow including submandibular gland tissue blood flow (SBF) and internal
carotid artery blood flow (ICBF) in rabbits during sevoflurane anesthesia. Twelve male
Japan White rabbits were anesthetized with sevoflurane and remifentanil. Remifentanil was
infused at 0.2 and 0.4 µg/kg/min. Measurements included circulatory
variables, common and external carotid artery blood flow (CCBF, ECBF), ICBF, tongue
mucosal blood flow (TMBF), masseter muscle tissue blood flow (MBF), mandibular bone marrow
tissue blood flow (BBF), tongue muscle tissue blood flow (TBF) and SBF. Vascular
resistances for each tissue, including the tongue mucosa, masseter muscle, mandibular bone
marrow, tongue muscle and submandibular gland, were calculated by dividing the mean
arterial pressure by the respective tissue blood flow. Remifentanil infusion decreased
oral tissue blood flow and circulatory variables. CCBF, ECBF and ICBF did not change. The
calculated vascular resistance in each oral tissue, except for the tongue mucosa,
increased in an infusion-rate-dependent manner. These results showed that remifentanil
infusion reduced TMBF, MBF, BBF, TBF and SBF in an infusion-rate-dependent manner without
affecting ICBF under sevoflurane anesthesia.
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Affiliation(s)
- Atsushi Hirata
- Department of Dental Anesthesiology, Tokyo Dental College, Tokyo 101-0061, Japan
| | - Masataka Kasahara
- Department of Pharmacology, Tokyo Dental College, Tokyo 101-0061, Japan
| | - Nobuyuki Matsuura
- Department of Dental Anesthesiology, Tokyo Dental College, Tokyo 101-0061, Japan
| | - Tatsuya Ichinohe
- Department of Dental Anesthesiology, Tokyo Dental College, Tokyo 101-0061, Japan
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Gökçek E, Kaydu A, Akdemir MS, Akil F, Akıncı IO. Early postoperative recovery after intracranial surgical procedures. Comparison of the effects of sevoflurane and desflurane. Acta Cir Bras 2016; 31:638-644. [DOI: 10.1590/s0102-865020160090000010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 08/23/2016] [Indexed: 12/26/2022] Open
Affiliation(s)
- Erhan Gökçek
- Diyarbakır Selahaddini Eyyubi State Hospital, Turkey
| | - Ayhan Kaydu
- Diyarbakır Selahaddini Eyyubi State Hospital, Turkey
| | | | - Ferit Akil
- Diyarbakır Selahaddini Eyyubi State Hospital, Turkey
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Orliaguet G. [Sedation and analgesia in emergency structure. Paediatry: Which sedation and analgesia for pediatric patients? Pharmacology]. ANNALES FRANCAISES D'ANESTHESIE ET DE REANIMATION 2012; 31:359-368. [PMID: 22445224 DOI: 10.1016/j.annfar.2012.01.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- G Orliaguet
- Département d'anesthésie-réanimation, hôpital Necker-Enfants-malades, université Paris Descartes, Paris 5, 149, rue de Sèvres, 75730 Paris cedex 15, France.
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Barak M, Greenberg Z, Danino J. Delayed awakening following inadvertent high-dose remifentanil infusion in a 13 year old patient. J Clin Anesth 2011; 23:322-4. [PMID: 21663820 DOI: 10.1016/j.jclinane.2010.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2009] [Revised: 05/27/2010] [Accepted: 07/24/2010] [Indexed: 10/18/2022]
Abstract
We report the case of a 13 year old patient who received 3.0 mg of remifentanil during a 50-minute surgical procedure as a result of a dosage miscalculation. The patient failed to awaken at the conclusion of the procedure and showed signs of opioid overdose. She recovered spontaneously two hours later.
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Affiliation(s)
- Michal Barak
- Department of Anesthesiology, Rambam Health Care Campus, affiliated with the Bruce Rappaport Faculty of Medicine, Technion, Haifa 31096, Israel.
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Calvo Vecino JM, Abad Gurumeta A, Garrido Reche E, Chao Novo K, Orts Castro A, Tomás Lachos J. [Transcranial Doppler ultrasound, bispectral index, and electroencephalographic monitoring of entropy during pediatric total intravenous anesthesia]. REVISTA ESPANOLA DE ANESTESIOLOGIA Y REANIMACION 2010; 57:621-629. [PMID: 22283014 DOI: 10.1016/s0034-9356(10)70298-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND AND OBJECTIVE Transcranial Doppler ultrasound is a noninvasive technique for monitoring the velocity of blood flow in the main intracranial arteries, particularly those in the circle of Willis. Our aim was to assess whether changes in cerebral arterial blood flow in anesthetized pediatric patients detected by pulsed Doppler ultrasound correlate with changes in the bispectral (BIS) index and electroencephalographic state and response entropy (ES and ER, respectively). MATERIAL AND METHODS Prospective, blinded observational study of 36 pediatric patients (age range, 5 to 11 years) under total intravenous anesthesia for minor surgical procedures. Propofol and fentanyl were used for induction; propofol and remifentanil in continuous perfusion and a single dose of cisatracurium were used for maintenance. In all patients we monitored hemodynamic and respiratory patterns, gases, temperature, and hypnosis (BIS, ES and ER) as well as cerebral blood flow estimated by pulsed Doppler ultrasound in the middle cerebral artery. Raw data were subjected to statistical smoothing. The resistance index, pulsatility index, mean velocity, and estimated baseline cerebral blood flow were calculated from the Doppler sonogram. We then studied the correlations between the Doppler-derived values and BIS, ES, ER, fraction of end-tidal carbon dioxide, and temperature. The variables were entered into logistic regression. RESULTS The pattern at induction indicated high resistance (low mean velocities and high pulsatility indexes) until the lowest BIS and ES values of 31 and 29, respectively, were reached. During maintenance, the Doppler sonogram pattern was slower (normalization of the pulsatility index, the resistance index, and mean velocity). Changes in flow and absolute entropy and BIS values were statistically correlated (Pearson's r values > or = 0.91); there was 95.6% agreement between Doppler values and BIS and agreement between BIS and ES values of 35-45. On awakening, flow velocities approached baseline values when BIS and ES rose to between 90 and 98. The estimated cerebral blood flow underwent fluctuations coinciding with an approximately concomitant increase or decrease in BIS (r > 0.95); the response of BIS was slightly delayed by no more than a minute but there was no corresponding response of entropy measurements. CONCLUSIONS We report Doppler ultrasound patterns during anesthesia with propofol. Systems for monitoring hypnosis could be considered indirect measurements of cerebral blood flow; BIS measurements are more sensitive to flow change. Transcranial Doppler ultrasound facilitates the observation of changes in blood flow that occur at different levels of hypnosis during anesthesia.
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Affiliation(s)
- J M Calvo Vecino
- Servicio de Anestesiología y Reanimación, Complejo Hospitalario de Vallecas, Hospital Infanta Leonor, Vallecas, Madrid.
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Abad Gurumeta A, Calvo Vecino JM, Abad Motos A, Olidén Gutiérrez L, García Alvarez R, Nieto Moreno A. [Transcranial Doppler ultrasound, bispectral index, and electroencephalographic monitoring of entropy during sevoflurane anesthesia in children]. REVISTA ESPANOLA DE ANESTESIOLOGIA Y REANIMACION 2010; 57:630-638. [PMID: 22283015 DOI: 10.1016/s0034-9356(10)70299-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND AND OBJECTIVE Transcranial Doppler ultrasound is a noninvasive technique for monitoring the velocity of blood flow in the main intracranial arteries, particularly those in the circle of Willis. Our aim was to assess whether changes in cerebral arterial blood flow in pediatric patients under sevoflurane anesthesia demonstrated by pulsed Doppler ultrasound correlate with changes in the bispectral (BIS) index and electroencephalographic state and response entropy (ES and ER, respectively). MATERIAL AND METHODS Prospective, blinded observational study of 36 pediatric patients (age range, 5 to 11 years; ASA physical status classification, 1-2) under sevoflurane anesthesia for minor surgical procedures. Anesthesia was induced with sevoflurane and maintained with 2.5% sevoflurane in an inspired oxygen fraction of 50% in air. A continuous perfusion of remifentanil was provided for analgesia. In all patients we monitored hemodynamic and respiratory patterns, gases, temperature, and hypnosis (BIS, ES and ER) as well as cerebral blood flow estimated by pulsed Doppler ultrasound in the middle cerebral artery. The resistance index, pulsatility index, mean velocity, and estimated baseline cerebral blood flow were calculated from the Doppler sonogram. Correlations (Pearson's r) were calculated between BIS, ES, ER, the pulsatility index, resistance index, mean flow velocity, estimated cerebral blood flow, fraction of end-tidal carbon dioxide, and temperature. A regression model was constructed. RESULTS Induction caused a pattern of high velocity (elevated mean velocity and normal or reduced pulsatility index) until the lowest BIS and ES values of 31 and 29, respectively, were reached. During maintenance, the Doppler sonogram pattern was slower (normalization of the pulsatility index, the resistance index, and mean velocity). Changes in flow and absolute entropy and BIS values were statistically correlated (Pearson's r values > or = 0.91); there was 95.6% agreement between Doppler values and BIS and agreement between BIS and ES values of 35 to 45. On awakening, flow velocities approached baseline values when BIS and ES rose to between 90 and 98. The estimated cerebral blood flow underwent fluctuations coinciding with an approximately concomitant increase or decrease in BIS (r > 0.95); the BIS response occurred with a slight delay of no more than a minute. The entropy measurements did not reflect the fluctuations. CONCLUSIONS We show Doppler ultrasound patterns during anesthetic induction with sevoflurane. Systems for monitoring hypnosis could be considered indirect measurements of cerebral blood flow; BIS measurements are more sensitive to change. Transcranial Doppler ultrasound facilitates the observation of changes in blood flow that occur at different levels of hypnosis during anesthesia.
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Affiliation(s)
- A Abad Gurumeta
- Servicio de Anestesiología y Reanimación del Hospital Infanta Sofía, Madrid
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Stroumpos C, Manolaraki M, Paspatis GA. Remifentanil, a different opioid: potential clinical applications and safety aspects. Expert Opin Drug Saf 2010; 9:355-64. [PMID: 20175702 DOI: 10.1517/14740331003672579] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD Opioids play an important role in every aspect of modern anesthetic practice. Remifentanil is an ultra-short-acting opioid featuring a unique pharmacokinetic profile allowing clinical versatility and improved control of its action. In this review, we assess the pharmacology of remifentanil, its clinical uses as well as safety issues on its action on the major organ systems and in particular clinical settings. AREAS COVERED IN THIS REVIEW A synthesis of evidence from a MEDLINE search for articles from 1993 to 2009 for available up-to-date information on remifentanil and its current applications and safety profile. WHAT THE READER WILL GAIN A synopsis of the unique pharmacokinetic properties of remifentanil and its action on major organ systems will provide insight on the safe and effective use of the drug in a variety of clinical settings. TAKE HOME MESSAGE Remifentanil is a valuable opioid in the armamentarium of the clinician, providing great clinical flexibility and safety but vigilance is required to avoid pitfalls.
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Affiliation(s)
- Charalampos Stroumpos
- Department of Gastroenterology, Benizelion General Hospital, L Knossou, Heraklion, Crete 71409, Greece.
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Abstract
Remifentanil has gained the confidence of anesthesiologists and has given a real opportunity to change the way anesthesia is given. It can be considered the ideal opioid despite many obstacles to pediatric use: the condition of 'off-label', the lack of wide randomized clinical trials, and the fear of adverse events because of its high potency. Experiences in the field with this opioid over the years encouraged its use. Use has been associated with N(2)0 and volatile agents for general anesthesia and with propofol for total intravenous anesthesia (TIVA). It seems very useful for sedation inside and outside the operating room and in intensive care for both short painful procedures and synchronization with mechanical ventilation. However, its unique pharmacokinetic characteristics causing rapid onset and offset of effect appear unchanged in small children and even in premature neonates and need to be really confirmed by further pharmacokinetic studies. Moreover, the real risks of tolerance and hyperalgesia should be evaluated in the pediatric population. In this review, we go through the newer aspects of this versatile drug that has been proposed as 'the pediatric anesthetist's opiate'.
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Affiliation(s)
- Maria Sammartino
- Department of Anaesthesia and Intensive Care, Catholic University of Sacred Heart, Rome, Italy.
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Abstract
BACKGROUND AND AIM Remifentanil is an ultra-short-acting opioid, increasingly used today in neuroanesthesia and neurointensive care. Its characteristics make remifentanil a potentially ideal agent, but previous data have cast a shadow on this opioid, supporting potentially toxic effects on the ischemic brain. The aim of the present concise review is to survey available up-to-date information on the effects of remifentanil on the central nervous system. METHOD A MEDLINE search within the past seven years for available up-to-date information on remifentanil and brain was performed. RESULTS Concise up-to-date information on the effects of remifentanil on the central nervous system was reported, with a particular emphasis on the following topics: cerebral metabolism, electroencephalogram, electrocorticography, motor-evoked potentials, regional cerebral blood flow, cerebral blood flow velocity, arterial hypotension and hypertension, intracranial pressure, cerebral perfusion pressure, cerebral autoregulation, cerebrovascular CO(2) reactivity, cerebrospinal fluid, painful stimulation, analgesia and hyperalgesia, neuroprotection, neurotoxicity and hypothermia. CONCLUSION The knowledge of the influence of remifentanil on brain functions is crucial before routine use in neuroanesthesia to improve anesthesia performance and patient safety as well as outcome.
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Affiliation(s)
- V Fodale
- Department of Neuroscience, Psychiatric and Anesthesiological Sciences, University of Messina, Messina, Italy.
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Fodale V, Schifilliti D, Conti A, Lucanto T, Pino G, Santamaria LB. Transcranial Doppler and anesthetics. Acta Anaesthesiol Scand 2007; 51:839-47. [PMID: 17635391 DOI: 10.1111/j.1399-6576.2007.01355.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Transcranial Doppler (TCD) is widely used to investigate the effects of anesthetic drugs on cerebral blood flow. Its repeatability and non-invasivity makes it an ideal, first choice method. Anesthesia providers are required to be conscious of the cerebral hemodynamic effects of drugs given in their practice, especially in neurosurgery and in subjects with impaired brain functions. The purpose of this review is to present the basic concepts of the TCD technique and the effects on cerebral hemodynamics of the most popular anesthetic drugs evaluated using TCD ultrasonography.
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Affiliation(s)
- V Fodale
- Department of Neuroscience, Psychiatric and Anesthesiological Sciences, University of Messina, Messina, Italy.
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Steinmetz J, Holm-Knudsen R, Sørensen MK, Eriksen K, Rasmussen LS. Hemodynamic differences between propofol-remifentanil and sevoflurane anesthesia for repair of cleft lip and palate in infants. Paediatr Anaesth 2007; 17:32-7. [PMID: 17184429 DOI: 10.1111/j.1460-9592.2006.01999.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Propofol-remifentanil anesthesia is widely used in adults but few studies are available in infants. We aimed at comparing the hemodynamic effects of propofol-remifentanil vs sevoflurane-fentanyl anesthesia. In addition, we sought to investigate recovery and whether remifentanil induced acute opioid tolerance. METHODS In total, 39 infants 4-6 months old were prospectively enrolled and randomized to receive either a combination of remifentanil and propofol (n = 17) or a sevoflurane-fentanyl anesthesia (n = 22) for surgical repair of cleft lip and palate. In both groups, sevoflurane was used for induction of anesthesia and fentanyl was administered before tracheal extubation. Mean arterial blood pressure and heart rate were recorded every 5 min after induction. We also recorded time from termination of surgery to tracheal extubation, postoperative behavior and the need for analgesia for the first 24 h after surgery. Postoperative observations were blinded. RESULTS In the remifentanil-propofol group, the mean arterial blood pressure was higher [58 (51-65) vs 51 (45-55), P = 0.02] and the mean heart rate was lower [111 (108-113) vs 128 (122-143), P < 0.0001]. There were no differences in recovery time or behavior after surgery. In the remifentanil group, a median fentanyl dose of 4 microg x kg(-1) was required to insure a smooth recovery, but there was no difference in morphine consumption during the first 24 h after surgery. CONCLUSIONS A high-dose remifentanil-propofol infusion was associated with a higher blood pressure and lower heart rate than sevoflurane-fentanyl anesthesia in infants. Postoperative morphine consumption, recovery time and quality were similar.
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Affiliation(s)
- Jacob Steinmetz
- Department of Anesthesia, Centre of Head and Orthopedics, Copenhagen University Hospital, Copenhagen, Denmark.
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Smith JH, Karsli C, Lagacé A, Luginbuehl I, Barlow R, Bissonnette B. Cerebral blood flow velocity increases when propofol is changed to desflurane, but not when isoflurane is changed to desflurane in children. Acta Anaesthesiol Scand 2005; 49:23-7. [PMID: 15675977 DOI: 10.1111/j.1399-6576.2004.00535.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND Children may exhibit delayed emergence following maintenance of anesthesia with propofol or isoflurane. Desflurane is often used towards the end of procedures to facilitate emergence. This study evaluated the effect on middle cerebral artery blood flow velocity (Vmca) in anesthetized children when propofol or isoflurane was substituted with desflurane. METHODS Forty-two healthy children aged 1-6 years were enrolled. A standardized anesthetic induction was used. Anesthesia was maintained with remifentanil (0.5 microg.kg(-1) bolus followed by an infusion of 0.2 microg.kg(-1).min(-1)) and a randomly selected sequence of propofol/desflurane/propofol, desflurane/propofol/desflurane, isoflurane/desflurane/isoflurane or desflurane/isoflurane/desflurane. Propofol was administered to maintain a steady-state serum concentration of 3 microg.ml(-1). Desflurane and isoflurane were administered at age-corrected 1 MAC. Hemodynamic stability was maintained. Transcranial Doppler sonography was used to measure Vmca. Hemodynamic variables as well as Vmca were measured 30 min after skin incision and repeated 30 min after each change in anesthetic maintenance agent. RESULTS The mean age and weight was 2.3 +/- 1.3 years and 13.0 +/- 3.7 kg, respectively. The Vmca (mean) increased by 35% from 37.7 +/- 10.5 cm s(-1) to 57.8 +/- 14.6 cm s(-1) (P < 0.0001) when propofol was changed to desflurane but was unaffected when desflurane replaced isoflurane. CONCLUSION When propofol is changed to desflurane, cerebral blood flow velocity increases significantly in normal children. This cerebral vasodilatory effect may have important implications in the neurosurgical setting.
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Affiliation(s)
- J H Smith
- Department of Anesthesia, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada
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Barlow R, Karsli C, Luginbuehl I, Bissonnette B. Desflurane increases cerebral blood flow velocity when used for rapid emergence from propofol anesthesia in children. Can J Anaesth 2004; 51:824-8. [DOI: 10.1007/bf03018457] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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