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Denchev K, Gomez J, Chen P, Rosenblatt K. Traumatic Brain Injury: Intraoperative Management and Intensive Care Unit Multimodality Monitoring. Anesthesiol Clin 2023; 41:39-78. [PMID: 36872007 DOI: 10.1016/j.anclin.2022.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
Traumatic brain injury is a devastating event associated with substantial morbidity. Pathophysiology involves the initial trauma, subsequent inflammatory response, and secondary insults, which worsen brain injury severity. Management entails cardiopulmonary stabilization and diagnostic imaging with targeted interventions, such as decompressive hemicraniectomy, intracranial monitors or drains, and pharmacological agents to reduce intracranial pressure. Anesthesia and intensive care requires control of multiple physiologic variables and evidence-based practices to reduce secondary brain injury. Advances in biomedical engineering have enhanced assessments of cerebral oxygenation, pressure, metabolism, blood flow, and autoregulation. Many centers employ multimodality neuromonitoring for targeted therapies with the hope to improve recovery.
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Affiliation(s)
- Krassimir Denchev
- Department of Anesthesiology, Wayne State University, 44555 Woodward Avenue, SJMO Medical Office Building, Suite 308, Pontiac, MI 48341, USA
| | - Jonathan Gomez
- Department of Anesthesiology & Critical Care Medicine, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Phipps 455, Baltimore, MD 21287, USA
| | - Pinxia Chen
- Department of Anesthesiology and Critical Care Medicine, St. Luke's University Health Network, 801 Ostrum Street, Bethlehem, PA 18015, USA
| | - Kathryn Rosenblatt
- Department of Anesthesiology & Critical Care Medicine, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Phipps 455, Baltimore, MD 21287, USA; Department of Neurology, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Phipps 455, Baltimore, MD 21287, USA.
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Slupe AM, Kirsch JR. Effects of anesthesia on cerebral blood flow, metabolism, and neuroprotection. J Cereb Blood Flow Metab 2018; 38:2192-2208. [PMID: 30009645 PMCID: PMC6282215 DOI: 10.1177/0271678x18789273] [Citation(s) in RCA: 172] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 06/11/2018] [Accepted: 06/25/2018] [Indexed: 12/12/2022]
Abstract
Administration of anesthetic agents fundamentally shifts the responsibility for maintenance of homeostasis from the patient and their intrinsic physiological regulatory mechanisms to the anesthesiologist. Continuous delivery of oxygen and nutrients to the brain is necessary to prevent irreversible injury and arises from a complex series of regulatory mechanisms that ensure uninterrupted cerebral blood flow. Our understanding of these regulatory mechanisms and the effects of anesthetics on them has been driven by the tireless work of pioneers in the field. It is of paramount importance that the anesthesiologist shares this understanding. Herein, we will review the physiological determinants of cerebral blood flow and how delivery of anesthesia impacts these processes.
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Affiliation(s)
- Andrew M Slupe
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, USA
| | - Jeffrey R Kirsch
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, USA
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Pelentritou A, Kuhlmann L, Cormack J, Woods W, Sleigh J, Liley D. Recording Brain Electromagnetic Activity During the Administration of the Gaseous Anesthetic Agents Xenon and Nitrous Oxide in Healthy Volunteers. J Vis Exp 2018. [PMID: 29364232 DOI: 10.3791/56881] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Anesthesia arguably provides one of the only systematic ways to study the neural correlates of global consciousness/unconsciousness. However to date most neuroimaging or neurophysiological investigations in humans have been confined to the study of γ-Amino-Butyric-Acid-(GABA)-receptor-agonist-based anesthetics, while the effects of dissociative N-Methyl-D-Aspartate-(NMDA)-receptor-antagonist-based anesthetics ketamine, nitrous oxide (N2O) and xenon (Xe) are largely unknown. This paper describes the methods underlying the simultaneous recording of magnetoencephalography (MEG) and electroencephalography (EEG) from healthy males during inhalation of the gaseous anesthetic agents N2O and Xe. Combining MEG and EEG data enables the assessment of electromagnetic brain activity during anesthesia at high temporal, and moderate spatial, resolution. Here we describe a detailed protocol, refined over multiple recording sessions, that includes subject recruitment, anesthesia equipment setup in the MEG scanner room, data collection and basic data analysis. In this protocol each participant is exposed to varying levels of Xe and N2O in a repeated measures cross-over design. Following relevant baseline recordings participants are exposed to step-wise increasing inspired concentrations of Xe and N2O of 8, 16, 24 and 42%, and 16, 32 and 47% respectively, during which their level of responsiveness is tracked with an auditory continuous performance task (aCPT). Results are presented for a number of recordings to highlight the sensor-level properties of the raw data, the spectral topography, the minimization of head movements, and the unequivocal level dependent effects on the auditory evoked responses. This paradigm describes a general approach to the recording of electromagnetic signals associated with the action of different kinds of gaseous anesthetics, which can be readily adapted to be used with volatile and intravenous anesthetic agents. It is expected that the method outlined can contribute to the understanding of the macro-scale mechanisms of anesthesia by enabling methodological extensions involving source space imaging and functional network analysis.
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Affiliation(s)
| | - Levin Kuhlmann
- Centre for Human Psychopharmacology, Swinburne University of Technology
| | - John Cormack
- Department of Anaesthesia and Pain Management, St. Vincent's Hospital Melbourne
| | - Will Woods
- Brain and Psychological Science Research Centre, Swinburne University of Technology
| | - Jamie Sleigh
- Department of Anaesthesiology, University of Auckland
| | - David Liley
- Centre for Human Psychopharmacology, Swinburne University of Technology;
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Pronicka E. Hypocapnic hypothesis of Leigh disease. Med Hypotheses 2017; 101:23-27. [PMID: 28351484 DOI: 10.1016/j.mehy.2017.01.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 01/05/2017] [Accepted: 01/26/2017] [Indexed: 11/15/2022]
Abstract
Leigh syndrome (LS) is a neurogenetic disorder of children caused by mutations in at least 75 genes which impair mitochondrial bioenergetics. The changes have typical localization in basal ganglia and brainstem, and typical histological picture of spongiform appearance, vascular proliferation and gliosis. ATP deprivation, free radicals and lactate accumulation are suspected to be the causes. Hypocapnic hypothesis proposed in the paper questions the energy deprivation as the mechanism of LS. We assume that the primary harmful factor is hypocapnia (decrease in pCO2) and respiratory alkalosis (increase in pH) due to hyperventilation, permanent or in response to stress. Inside mitochondria, the pH signal of high pH/low bicarbonate ion (HCO-3) is transmitted by soluble adenyl cyclase (sAC) through cAMP dependent manner. The process can initiate brain lesions (necrosis, apoptosis, hypervascularity) in OXPHOS deficient cells residing at the LS area of the brain. The major message of the article is that it is not the ATP depletion but intracellular alkalization (and/or hyperoxia?) which seem to be the cause of LS. The paper includes suggestions concerning the methodology for further research on the LS mechanism and for therapeutic strategy.
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Affiliation(s)
- Ewa Pronicka
- The Children's Memorial Health Institute, Department of Pediatrics, Nutrition and Metabolic Diseases, Aleja Dzieci Polskich 20, 04-730 Warsaw, Poland.
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5
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de Vasconcellos K, Sneyd JR. Nitrous oxide: are we still in equipoise? A qualitative review of current controversies. Br J Anaesth 2013; 111:877-85. [PMID: 23801743 DOI: 10.1093/bja/aet215] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
This review considers the current position of nitrous oxide in anaesthetic practice and balances potential beneficial and disadvantageous effects. The classic adverse characteristics of nitrous oxide, such as diffusion hypoxia, expansion of gas-filled spaces, and postoperative nausea and vomiting, are often cited as reasons to avoid this old drug. Recent concerns regarding neurotoxicity, adverse cardiovascular outcomes, and wound complications have further hardened many practitioners against nitrous oxide. New evidence and underpinning mechanistic data, however, suggest potential beneficial effects on the central nervous system, cardiovascular system, and acute and chronic pain. While we await the outcome of large studies including ENIGMA-II, many clinicians have already decided against this agent. The authors argue that this abandonment may be premature. Clinical Trial Registration None required.
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Affiliation(s)
- K de Vasconcellos
- Department of Anaesthetics and Critical Care, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
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Greene NH, Lee LA. Modern and Evolving Understanding of Cerebral Perfusion and Autoregulation. Adv Anesth 2012; 30:97-129. [PMID: 28275288 DOI: 10.1016/j.aan.2012.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Nathaniel H Greene
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA 98195-6540, USA
| | - Lorri A Lee
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA 98195-6540, USA; Department of Neurological Surgery, University of Washington, Seattle, WA 98195-6540, USA
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Is nitrous oxide use appropriate in neurosurgical and neurologically at-risk patients? Curr Opin Anaesthesiol 2010; 23:544-50. [PMID: 20689409 DOI: 10.1097/aco.0b013e32833e1520] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE OF REVIEW To address controversial issues surrounding the use of nitrous oxide as a component of anesthesia in neurosurgical and neurologically at-risk patients. RECENT FINDINGS Nitrous oxide has been used as a component of general anesthesia for over 160 years and has contributed to countless apparently uneventful anesthetics in neurologically at-risk patients. Avoidance of nitrous oxide in specific circumstances, such as pre-existing pneumocephalus, during acute venous air embolism, and in patients with disorders of folate metabolism, is warranted. However, various controversies exist regarding the use of this drug in the general neurosurgical population. Specifically, some suggest a possible association between nitrous oxide and the postoperative development of tension pneumocephalus despite lack of data to support this notion. Additionally, data describing alterations of cerebral hemodynamics and metabolism and exacerbation of ischemic neurologic injury by nitrous oxide are inconsistent. Recent data derived from humans having cerebral aneurysm clipping failed to show any long-term adverse effect from the use of nitrous oxide on gross neurologic or cognitive function. SUMMARY Except in a few specific circumstances, there exists no conclusive evidence to support the dogmatic avoidance of nitrous oxide in neurosurgical patients.
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Szabó EZ, Luginbuehl I, Bissonnette B. Impact of anesthetic agents on cerebrovascular physiology in children. Paediatr Anaesth 2009; 19:108-18. [PMID: 19040505 DOI: 10.1111/j.1460-9592.2008.02826.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The role of the pediatric neuroanesthetist is to provide comprehensive care to children with neurologic pathologies. The cerebral physiology is influenced by the developmental stage of the child. The understanding of the effects of anesthetic agents on the physiology of cerebral vasculature in the pediatric population has significantly increased in the past decade allowing a more rationale decision making in anesthesia management. Although no single anesthetic technique can be recommended, sound knowledge of the principles of cerebral physiology and anesthetic neuropharmacology will facilitate the care of pediatric neurosurgical patients.
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Affiliation(s)
- Elöd Z Szabó
- Department of Anaesthesia, University of Toronto, Toronto, ON, Canada.
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Reinstrup P, Ryding E, Ohlsson T, Sandell A, Erlandsson K, Ljunggren K, Salford L, Strand S, Uski T. Regional cerebral metabolic rate (positron emission tomography) during inhalation of nitrous oxide 50% in humans. Br J Anaesth 2008; 100:66-71. [DOI: 10.1093/bja/aem334] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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11
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Cole CD, Gottfried ON, Gupta DK, Couldwell WT. TOTAL INTRAVENOUS ANESTHESIA. Oper Neurosurg (Hagerstown) 2007; 61:369-77; discussion 377-8. [DOI: 10.1227/01.neu.0000303996.74526.30] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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12
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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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Abstract
The volatile anaesthetics sevoflurane and desflurane feature new and promising properties. Their low blood and tissue solubility enables rapid onset of and emergence from anaesthesia, thus enhancing patient safety and comfort. This article is designed as an up-to-date review of the pharmacokinetic and pharmacodynamic properties of modern volatile anaesthetics. The first part focuses on pharmacokinetic issues such as substance properties, uptake and elimination. The second part covers the effects of inhaled anaesthetics on organ systems, with emphasis on the central nervous system, the cardiovascular system, the respiratory tract, liver and kidneys.
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Affiliation(s)
- Benedikt Preckel
- Department of Anaesthesiology, Düsseldorf University Hospital, Düsseldorf, Germany.
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Iacopino DG, Conti A, Battaglia C, Siliotti C, Lucanto T, Santamaria LB, Tomasello F. Transcranial Doppler ultrasound study of the effects of nitrous oxide on cerebral autoregulation during neurosurgical anesthesia: a randomized controlled trial. J Neurosurg 2003; 99:58-64. [PMID: 12854745 DOI: 10.3171/jns.2003.99.1.0058] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Nitrous oxide has an adverse effect on cerebrovascular hemodynamics. Increased intracranial pressure, cerebral blood flow (CBF), cerebral metabolic rate of O2 (CMRO2), and reduced autoregulation indices have been reported, but their magnitudes are still being debated. This study was designed to evaluate the effect of N2O on CBF and autoregulatory indexes during N2O-sevoflurane anesthesia in a prospective randomized controlled series of patients. METHODS Two groups of 20 patients were studied on the basis of the use of N2O in the anesthetic gas mixture. The transient hyperemic response test, which relies on transcranial Doppler ultrasound techniques, was used to assess cerebral hemodynamics. The time-averaged mean flow velocity, considered to be an index of actual CBF, increased significantly (p < 0.001) after introduction of N2O. The hyperemic response, considered as the index of autoregulatory potential, decreased significantly after introduction of N2O into the gas mixture (p < 0.001). CONCLUSIONS The increase in CBF and the reduction in autoregulatory indices suggest caution in using N2O during sevoflurane anesthesia, especially in patients with reduced autoregulatory reserve and during neurosurgical interventions. Transcranial Doppler ultrasonography is an efficacious method to evaluate the effects of anesthetic agents on CBF.
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Affiliation(s)
- Domenico G Iacopino
- Neurosurgical Clinic, University of Messina School of Medicine, Messina, Italy.
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15
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Barr G, Anderson R, Jakobsson J. The effects of nitrous oxide on the auditory evoked potential index during sevoflurane anaesthesia. Anaesthesia 2002; 57:736-9. [PMID: 12133083 DOI: 10.1046/j.1365-2044.2002.02693.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have studied the effects of nitrous oxide on the auditory evoked response index (AAI-index) derived from the A-line monitoring device during sevoflurane anaesthesia in 21 patients undergoing minor ambulatory surgery. During sevoflurane anaesthesia with an AAI-index < 30, the addition or withdrawal of nitrous oxide in a concentration of 66% end tidal did not show any linear dose dependent change in AAI-index . However, comparing nitrous oxide > 40% to nitrous oxide < 10% end tidal concentration the AAI-index did decrease, p < 0.05. The AAI-index is either non-linear at deeper anaesthetic levels or is insensitive to the anaesthetic effects of nitrous oxide in terms of MAC-multiples.
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Affiliation(s)
- G Barr
- Department of Cardiothoracic Anaesthetics and Intensive Care, Karolinska Hospital, Stockholm, Sweden
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Muñoz HR, Núñez GE, de la Fuente JE, Campos MG. The effect of nitrous oxide on jugular bulb oxygen saturation during remifentanil plus target-controlled infusion propofol or sevoflurane in patients with brain tumors. Anesth Analg 2002; 94:389-92, table of contents. [PMID: 11812705 DOI: 10.1097/00000539-200202000-00030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
UNLABELLED During propofol/fentanyl anesthesia, a large percentage of patients have jugular bulb oxygen saturation (SjO(2)) <50%. The incidence is less with isoflurane/N(2)O. We evaluated the effect of N(2)O on SjO(2) during remifentanil-based anesthesia with concurrent propofol or sevoflurane in 20 adults undergoing brain tumor surgery. Anesthesia was randomized: Group 1 (n = 10), target-controlled infusion propofol; and Group 2 (n = 10), thiopental 2-3 mg/kg followed by sevoflurane 0.9% end-tidal. Jugular bulb and arterial blood samples for gas analysis were withdrawn during the administration of oxygen 33% with nitrogen 67% and then with N(2)O 67%. All samples were drawn before surgery and 20 min after the addition of the study gas and with an ETCO(2) 26-28 mm Hg and mean arterial pressure >90 mm Hg. Both groups had similar demographic and physiologic data. In the Propofol group, SjO(2) was 50% +/- 10% with nitrogen and 52% +/- 9% with N(2)O (not significant); in the Sevoflurane group, however, N(2)O 67% increased SjO(2) from 56% +/- 13% to 66% +/- 12% (P < 0.01). This indicates that N(2)O does not reduce the incidence of low SjO(2) values during propofol anesthesia. IMPLICATIONS This study demonstrates that nitrous oxide can increase jugular bulb venous oxygen saturation when added to sevoflurane/remifentanil anesthesia, but not to propofol/remifentanil anesthesia, in patients with brain tumors.
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Affiliation(s)
- Hernán R Muñoz
- Department of Anesthesiology, Catholic University School of Medicine, Santiago, Chile.
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Muñoz HR, Núñez GE, de la Fuente JE, Campos MG. The Effect of Nitrous Oxide on Jugular Bulb Oxygen Saturation During Remifentanil Plus Target-Controlled Infusion Propofol or Sevoflurane in Patients with Brain Tumors. Anesth Analg 2002. [DOI: 10.1213/00000539-200202000-00030] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
Anaesthesia for the surgical treatment of supratentorial tumours requires an understanding of: the pathophysiology of a localised or generalised increase in intracranial pressure (ICP), the regulation and maintenance of intracerebral perfusion, avoidance of secondary systemic insults to the brain, and the effects of anaesthetic drugs on ICP, cerebral perfusion and cerebral metabolism. Knowledge of the therapeutic options available for decreasing ICP, brain bulk and brain tension perioperatively is also essential. Potential complications which may present during supratentorial neurosurgery include massive intraoperative haemorrhage and seizures. The fact that the surgeon is operating on a tensed brain is also a potential source of difficulty. The need to monitor brain function and environment during surgery poses a challenge to the anaesthesiologist, as does the achievement of rapid emergence from anaesthesia with the adequate use of anaesthetic drugs.
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Affiliation(s)
- P Ravussin
- Département d' Anaesthésiologie et de Réanimation, Hôpital de Sion, Switzerland.
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Pronicka E, Piekutowska-Abramczuk DH, Popowska E, Pronicki M, Karczmarewicz E, Sykut-Cegielskâ Y, Taybert J. Compulsory hyperventilation and hypocapnia of patients with Leigh syndrome associated with SURF1 gene mutations as a cause of low serum bicarbonates. J Inherit Metab Dis 2001; 24:707-14. [PMID: 11804207 DOI: 10.1023/a:1012937204315] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Experimental data show that elevation of intracellular pH leads to severe lesions of brain cells. Acidification of intracellular fluid by accumulation of lactate may compensate the effect of respiratory alkalosis. Increased serum pH, and low PCO2, associated with hyperlactataemia (sometimes incorrectly called 'acidosis') have been reported in children with Leigh syndrome (LS). The aim of the study was to determine whether respiratory alkalosis is characteristic of patients with LS due to SURF1 mutations. All venous blood gas data (88 samples) of 18 spontaneously breathing LS patients with recently established SURF1 mutations, hospitalized during 1986-2000, were retrospectively reviewed. The data of an affected boy who survived on a respirator for more than 3 months (79 daily samples) were analysed separately. In spontaneously breathing patients, the data indicated that the patients had compensated or partially compensated respiratory alkalosis (pH 7.388+/-0.060, Pco2 29.2+/-5.7 mmHg, HCO3- 17.4+/-3.0 mmol/L, BE -6.7+/-3.2 mmol/L). Bicarbonate excretion was detected in urine of two examined LS cases in spite of decreased serum HCO3-. In the affected child maintained on a respirator, simple manipulation of the inspired CO2 tension to establish a normal pressure of 35-45 mmHg automatically caused an increase of serum HCO3- concentration to a normal value of 26.3+/-2.9 mmol/L (and BE to +2.2+/-3.1 mmol/L), in spite of cytochrome oxidase (COX) deficiency due to a confirmed SURF1 mutation. We suggest that respiratory alkalosis (hypocapnia) of Leigh syndrome patients with SURF1 mutations results from compulsory hyperventilation and speculate that hypocapnia may contribute to Leigh-like brain damage in the SURF1-deficient patients as well as in other patients presenting with Leigh-like syndrome. The supposition that accumulation of lactate may protect the brain of LS patients from alkalosis-related damage requires further study. Avoidance of any factors stimulating hyperventilation of LS patients and caution when attempting to correct low plasma bicarbonate are suggested.
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Affiliation(s)
- E Pronicka
- Department of Metabolic Diseases, Children's Memorial Health Institute, Warsaw, Poland.
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Bowie RA, O’Connor PJ, Hardman JG, Mahajan RP. The Effect of Continuous Positive Airway Pressure on Cerebral Blood Flow Velocity in Awake Volunteers. Anesth Analg 2001. [DOI: 10.1213/00000539-200102000-00026] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Bowie RA, O'Connor PJ, Hardman JG, Mahajan RP. The effect of continuous positive airway pressure on cerebral blood flow velocity in awake volunteers. Anesth Analg 2001; 92:415-7. [PMID: 11159243 DOI: 10.1097/00000539-200102000-00026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We measured the effect of 5 and 10 cm H(2)O continuous positive airways pressure (CPAP) on middle cerebral artery blood flow velocity (FV) in 15 awake, healthy volunteers by using transcranial Doppler ultrasonography. Mean, systolic, and diastolic FV plus pulsatility index were recorded. No significant change in any measured variable was observed with the application of 5 or 10 cm H(2)O CPAP. These results are in contrast to those of a previous study, which found a significant increase in mean FV and a decrease in pulsatility index during the application of 12 cm H(2)O CPAP.
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Affiliation(s)
- R A Bowie
- University Department of Anaesthesia and Intensive Care, City Hospital, Nottingham, UK
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Jugular Bulb Oxygen Saturation During Propofol and Isoflurane/Nitrous Oxide Anesthesia in Patients Undergoing Brain Tumor Surgery. Anesth Analg 1999. [DOI: 10.1213/00000539-199908000-00021] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Jansen GF, van Praagh BH, Kedaria MB, Odoom JA. Jugular bulb oxygen saturation during propofol and isoflurane/nitrous oxide anesthesia in patients undergoing brain tumor surgery. Anesth Analg 1999; 89:358-63. [PMID: 10439748 DOI: 10.1097/00000539-199908000-00021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
UNLABELLED We investigated, in brain tumor patients, the jugular bulb venous oxygen partial pressure (PjO2) and hemoglobin saturation (SjO2), the arterial to jugular bulb venous oxygen content difference (AJDO2), and middle cerebral artery blood flow velocity (Vmca) during anesthesia, and the effect of hyperventilation on these variables. Twenty patients were randomized to receive either isoflurane/ nitrous oxide/fentanyl (Group 1) or propofol/fentanyl (Group 2). At normoventilation (PacO2 35 +/- 2 mm Hg in Group 1 and 33 +/- 3 mm Hg in Group 2), SjO2 and PjO2 were significantly higher in Group 1 than in Group 2 (SjO2 60% +/- 6% and 49% +/- 13%, respectively; P = 0.019) (PjO2 32 +/- 3 and 27 +/- 5 mm Hg, respectively; P = 0.027). In Group 2, 5 of 10 patients had SjO2 < 50%, and 3 of these patients had SjO2 < 40% and AJDO2 > 9 mL/dL. All patients in Group 1 had SjO2 > 50%. During hyperventilation, there were no differences in SjO2, PjO2, or AJDO2 between the two groups. On hyperventilation, there was no correlation between the relative decreases of Vmca and 1/AJDO2 (r = 0.21, P = 0.41). The results indicate during propofol anesthesia, half of the brain tumor patients showed signs of cerebral hypoperfusion, but not during isoflurane/nitrous oxide anesthesia. Furthermore, during PacO2 manipulations, shifts in Vmca are inadequate to evaluate brian oxygen delivery in these patients. IMPLICATIONS During propofol anesthesia at normoventilation, 50% of brain tumor patients showed signs suggesting cerebral hypoperfusion, but this could not be demonstrated during isoflurane/nitrous oxide anesthesia. During PacO2 manipulations, consecutive measurements of the cerebral blood flow velocity may be inadequate to assess cerebral oxygenation.
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Affiliation(s)
- G F Jansen
- Department of Anesthesiology, Academic Medical Centre, University of Amsterdam, The Netherlands
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The Effects of Sevoflurane and Nitrous Oxide on Middle Cerebral Artery Blood Flow Velocity and Transient Hyperemic Response. Anesth Analg 1999. [DOI: 10.1213/00000539-199907000-00030] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Bedforth NM, Girling KJ, Harrison JM, Mahajan RP. The effects of sevoflurane and nitrous oxide on middle cerebral artery blood flow velocity and transient hyperemic response. Anesth Analg 1999; 89:170-4. [PMID: 10389798 DOI: 10.1097/00000539-199907000-00030] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
UNLABELLED We studied the effects of sevoflurane, with and without nitrous oxide, on the indices of cerebral autoregulation (transient hyperemic response ratio and the strength of autoregulation) derived from the transient hyperemic response (THR) test. Twelve patients (ASA physical status I or II) aged 18-40 yr presenting for routine non-neurosurgical procedures were recruited. The middle cerebral artery blood flow velocity was continuously recorded using transcranial Doppler ultrasonography. Preinduction THR tests were performed before the patients were anesthetized with alfentanil, propofol, and vecuronium. End-tidal carbon dioxide concentration and mean arterial pressure (to within 10% with a phenylephrine infusion) were maintained at their preinduction values. THR tests were performed sequentially at the following end-tidal sevoflurane concentrations: 2.2% in oxygen, 3.4% in oxygen, 3.4% with 50% nitrous oxide in oxygen, and 2.2% with 50% nitrous oxide in oxygen. Neither 2.2% nor 3.4% sevoflurane significantly affected cerebral autoregulation. The addition of 50% nitrous oxide to the 2.2%, but not the 3.4%, concentration of sevoflurane increased middle cerebral artery blood flow velocity and decreased autoregulatory indices significantly. IMPLICATIONS Transient hyperemic response is preserved during sevoflurane anesthesia but is significantly impaired when nitrous oxide is added to the lower concentration of sevoflurane (2.2%). These findings have implications for neurosurgical patients undergoing general anesthesia.
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Affiliation(s)
- N M Bedforth
- University Department of Anaesthesia and Intensive Care, Queen's Medical Centre and City Hospital NHS Trust, Nottingham, United Kingdom
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Oriot D, Nassimi A. [Intracranial hypertension in the infant: from its physiopathology to its therapeutic management]. Arch Pediatr 1998; 5:773-82. [PMID: 9759278 DOI: 10.1016/s0929-693x(98)80066-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The pathophysiology of elevated intracranial pressure (ICP) is assessed from a three cerebral compartment model and from brain compliance. The mechanisms leading to elevated ICP (expanding process, cerebral edema, brain swelling, hydrocephalus) and their consequences (brain herniation, ischemia-anoxia phenomenon, Cushing reaction and neurogenic pulmonary edema) are overviewed. The causes of elevated ICP in children are reported with emphasis on traumatology. Diagnostic procedures include clinical assessment, fundoscopy, cerebral computerized tomography scan and specific problems of cerebrospinal fluid investigation. Methods and results of intracranial pressure monitoring are reported. The treatment of elevated ICP is based upon clinical follow-up and monitoring of ICP. General therapeutic rules consist of adequate position, suppression of any neck, skull and abdominal compression, stimuli limitation and fluid restriction. Specific treatments include mechanical ventilation, sedation and analgesia, barbiturates, anticonvulsant drugs, mannitol, corticosteroids, hypothermia, enteral nutrition, and antibiotics.
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Affiliation(s)
- D Oriot
- Service de pédiatrie, hôpital Jean-Bernard, CHU, Poitiers, France
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Costello TG, Cormack JR. Clonidine Premedication Decreases Hemodynamic Responses to Pin Head-Holder Application During Craniotomy. Anesth Analg 1998. [DOI: 10.1213/00000539-199805000-00017] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Costello TG, Cormack JR. Clonidine premedication decreases hemodynamic responses to pin head-holder application during craniotomy. Anesth Analg 1998; 86:1001-4. [PMID: 9585285 DOI: 10.1097/00000539-199805000-00017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
UNLABELLED The aim of this study was to compare hemodynamic responses to intubation and pin head-holder application in two groups of neurosurgical patients given oral clonidine (3 microg/kg) or oral temazepam (10-20 mg) 90 min before the induction of anesthesia. Fifty patients undergoing elective craniotomy were randomized to either group. Anesthesia was induced with i.v. propofol 1500 mg/h, fentanyl 4 microg/kg, vecuronium 0.15 mg/kg, and lidocaine 1.5 mg/kg and was maintained with propofol 6 mg x kg(-1) x h(-1). Mean arterial blood pressure (MAP) and heart rate were recorded before the induction of anesthesia and before and after intubation and application of the pin head holder. Interventions required to maintain hemodynamic stability were compared between groups. Preinduction sedation scores and MAP values were similar between groups. MAP was significantly lower (P = 0.031) in the clonidine group after pin head-holder application. Interventions to stabilize MAP were not significantly different between groups (P = 0.11). We conclude that clonidine is effective in reducing the MAP increase with pin head-holder application in patients undergoing craniotomy. IMPLICATIONS In this study, we investigated an approach to the prevention of increased blood pressure often seen during the early part of anesthesia for brain surgery. Oral clonidine was effective in reducing the mean arterial blood pressure increase resulting from pin head-holder application. Clonidine, a blood pressure-reducing drug, was given to 25 patients before anesthesia. Their blood pressure measurements were then compared with those of 25 patients not given clonidine.
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Affiliation(s)
- T G Costello
- St. Vincent's Hospital, Fitzroy, Melbourne, Australia
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Porkkala T, Jäntti V, Kaukinen S, Häkkinen V. Nitrous oxide has different effects on the EEG and somatosensory evoked potentials during isoflurane anaesthesia in patients. Acta Anaesthesiol Scand 1997; 41:497-501. [PMID: 9150778 DOI: 10.1111/j.1399-6576.1997.tb04730.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Electroencephalogram (EEG) and somatosensory evoked potentials (SEPs) are altered by inhalation anaesthesia. Nitrous oxide is commonly used in combination with volatile anaesthetics. We have studied the effects of nitrous oxide on both EEG and SEPs simultaneously during isoflurane burst-suppression anaesthesia. METHODS Twelve ASA I-II patients undergoing abdominal or orthopaedic surgery were anaesthetized with isoflurane by mask. After intubation and relaxation the isoflurane concentration was increased to a level at which an EEG burst-suppression pattern occurred (mean isoflurane end-tidal concentration 1.9 (SD 0.2) %. With a stable isoflurane concentration, the patients received isoflurane-air-oxygen and isoflurane-nitrous oxide-oxygen (FiO2 0.4) in a randomized cross-over manner. EEG and SEPs were simultaneously recorded before, and after wash-out or wash-in periods for nitrous oxide. The proportion of EEG suppressions as well as SEP amplitudes for cortical N20 were calculated. RESULTS The proportion of EEG suppressions decreased from 53.5% to 34% (P < 0.05) when air was replaced by nitrous oxide. At the same time, the cortical N20 amplitude was reduced by 69% (P < 0.01). CONCLUSION The results suggest that during isoflurane anaesthesia, nitrous oxide has a different effect on EEG and cortical SEP at the same time. The effects of nitrous oxide may be mediated by cortical and subcortical generators.
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Affiliation(s)
- T Porkkala
- Department of Anaesthesia and Intensive Care, Tampere University Hospital, Finland
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Hahn RG, Riddez L, Brismar B, Strandberg A, Hedenstierna G. Haemodynamics during inhalation of a 50% nitrous-oxide-in-oxygen mixture with and without hypovolaemia. Acta Anaesthesiol Scand 1997; 41:485-91. [PMID: 9150776 DOI: 10.1111/j.1399-6576.1997.tb04728.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Inhalation of a gas mixture containing 50% nitrous oxide in oxygen (N2O/O2) is widely used for pain relief in emergency situations, which may also be associated with blood loss. The aim of this study was to evaluate the haemodynamic effects of this gas mixture in normo- and hypovolaemic subjects. METHODS Six healthy males were studied during inhalation of N2O/O2 before and after withdrawal of 900 ml of blood. On each occasion, we measured systemic and pulmonary arterial pressures, cardiac output, blood gases, extravascular lung water, and the blood flow and oxygen consumption in the whole body, liver and kidneys. RESULTS Inhalation of N2O/O2 reduced the stroke volume and increased peripheral resistance. Oxygen uptake decreased in the liver (-30%) and in the whole body (-23%). Blood withdrawal reduced the pulmonary arterial and central venous pressures (-30 to -50%) and further decreased stroke volume and the blood flows to the liver and the kidney (-15%). The extravascular lung water tended to increase both during inhalation of N2O/O2 and during hypovolaemia. CONCLUSION N2O/O2 aggravated the hypokinetic circulation induced by hypovolaemia. However, the oxygen consumption decreased only during inhalation of N2O/O2. This opens up the possibility that the cardiodepression associated with N2O/O2 is caused by a change in metabolic demands.
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Affiliation(s)
- R G Hahn
- Department of Anaesthesia, Huddinge University Hospital, Stockholm, Sweden
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Enlund M, Mentell O, Edmark L, Ronquist G. Low frequency of adenylate kinase release into cerebrospinal fluid during balanced, normotensive anaesthesia and a non-orthognathic surgical procedure. J Int Med Res 1997; 25:92-7. [PMID: 9100164 DOI: 10.1177/030006059702500206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Activity of strictly intracellular enzymes in the cerebrospinal fluid (CSF) may indicate leakage from dysfunctional brain cells. Increased activity of adenylate kinase (AK) in the CSF is indicative of brain cell injury arising from several sources, among them orthognathic surgery. The mechanism in the latter case is obscure, but the use of an oscillating saw which generates vibrations, and the site of surgery close to the brain may be contributing factors. Anaesthesia may also play a role. In the present study, CSF-AK activity was measured after hysterectomy and was compared with activity after orthognathic surgery in two other studies. Four of 19 patients (21%) in the present study expressed pathological activity, compared with 34 of 47 (72%) orthognathic patients in the two other studies. No firm conclusion may be drawn from historical comparisons, and the difference in activity seen between the two types of surgery might not necessarily be the result of surgical factors. Until this is investigated further, however, we conclude that there may be a difference in postoperative CSF-AK activity between orthognathic and lower abdominal surgery.
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Affiliation(s)
- M Enlund
- Department of Anaesthesia and Intensive Care, Central Hospital, Västerås, Sweden
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Inada T, Shingu K, Uchida M, Kawachi S, Tsushima K, Niitsu T. Changes in the cerebral arteriovenous oxygen content difference by surgical incision are similar during sevoflurane and isoflurane anaesthesia. Can J Anaesth 1996; 43:1019-24. [PMID: 8896853 DOI: 10.1007/bf03011903] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
PURPOSE To investigate changes of cerebral arteriovenous oxygen content difference (AVDO2) induced by surgical incision and to determine carbon dioxide (CO2) reactivity of the cerebral circulation during sevoflurane and isoflurane anaesthesia. METHODS Twenty-one ASA 1-2 patients undergoing elective surgery for supratentorial tumours were randomly allocated to receive either 1.3 MAC sevoflurane/N2O anaesthesia (n = 10) or equi-MAC isoflurane/N2O anaesthesia (n = 11). Before and after incision, haemodynamic measurements and AVDO2 determinations were performed. After opening the dura, AVDO2 was determined before and after the respiration rate was increased by 50%. RESULTS Incision produced an increase in mean arterial pressure from 69 +/- 11 to 97 +/- 22 mmHg (mean +/- SD) (P < 0.0005) and from 71 +/- 6 to 89 +/- 12 mmHg (P < 0.0001) in the sevoflurane and isoflurane groups, respectively, whereas the heart rate increased from 60 +/- 9 to 72 +/- 8 bpm (P < 0.001) and from 65 +/- 6 to 70 +/- 7 bpm (P < 0.001), respectively. Arterial carbon dioxide tension (PaCO2) was increased from 33.6 +/- 2.3 to 34.6 +/- 1.8 mmHg (P < 0.05) with incision in the sevoflurane group. The AVDO2 was decreased from 6.5 +/- 1.6 to 5.3 +/- 1.6 vol% (P < 0.0005) in the sevoflurane group and from 6.7 +/- 1.1 to 6.0 +/- 1.1 vol% (P < 0.01) in the isoflurane group. The % change of AVDO2 was larger in the sevoflurane group than in the isoflurane group (-18.3 +/- 8.4% vs -9.1 +/- 9.0%; P < 0.05) but no difference remained after the post-incisional AVDO2 value of the sevoflurane group was corrected for pre-incisional PaCO2. Carbon dioxide reactivity, calculated as the percent change in AVDO2 per mmHg change in PaCO2, was 6.1 +/- 3.0%.mmHg-1 in the sevoflurane group and 5.9 +/- 2.4%.mmHg-1 in the isoflurane group (P = NS). CONCLUSIONS Sevoflurane and isoflurane are associated with similar impairment of cerebral flow-metabolism coupling at incision, while CO2 reactivity is maintained during both anaesthetics.
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Affiliation(s)
- T Inada
- Department of Anesthesiology, Kansai Medical University Hospital, Osaka, Japan
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Enlund M, Mentell O, Engström C, Horneman G, Ronquist G. Occurrence of adenylate kinase in cerebrospinal fluid after isoflurane anaesthesia and orthognathic surgery. Ups J Med Sci 1996; 101:97-111. [PMID: 8740929 DOI: 10.3109/03009739609178916] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
UNLABELLED The study objective was, firstly, to investigate whether anaesthesia with induced arterial hypotension would cause leakage of a biochemical marker of neuronal injury, adenylate kinase (AK), into the cerebrospinal fluid (CSF). ( DEFINITION arterial hypotension = mean arterial pressure (MAP) 50-65 mmHg during > or = 10 min). Secondly, a subgroup of patients was examined with a limited battery of psychometric tests. Patients, scheduled for orthognathic surgery, were allocated to either hypotension (n = 20) or normotension (n = 20). Seventeen patients were subjected to psychometry. Arterial blood pressure was recorded continuously and controlled by adjustments of the administered concentration of the inhalational anaesthetic isoflurane. Fentanyl, an opioid, was given equally in both groups. A lumbar puncture was performed approximately 20 h post-operatively for a CSF sample, later analysed for AK activity. Neuropsychological tests were performed the day before surgery and the fourteenth day postoperatively. The CSF-AK value was pathologically increased ( > 0.040 U/L) in 24 patients (65%), of whom 9 were normotensive. There was no significant difference between the CSF-AK values in the hypotensive and normotensive groups, mean values were 0.082 (s.d. 0.051) and 0.066 (s.d. 0.059) U/L, respectively. The overall correlation between the 10 min MAP levels and the CSF-AK values was close to zero. In the pilot neuropsychological investigation some abnormalities were observed, indicating clinically significant adverse effects in four hypotensive patients, of whom two displayed pathologically increased CSF-AK values. At the group level, the correlation between the changes in psychometry and the measured CSF-AK values was poor. Increases in CSF-AK activities may be a non-specific occurrence in the perioperative interval, possibly indicating an adverse effect on the brain. Arterial hypotension could not be proven to explain the CSF-AK outcome.
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Affiliation(s)
- M Enlund
- Department of Anaesthesia and Intensive Care, Central Hospital, Västerås, Sweden
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Strebel S, Kaufmann M, Anselmi L, Schaefer HG. Nitrous oxide is a potent cerebrovasodilator in humans when added to isoflurane. A transcranial Doppler study. Acta Anaesthesiol Scand 1995; 39:653-8. [PMID: 7572016 DOI: 10.1111/j.1399-6576.1995.tb04143.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Nitrous oxide during neurosurgical procedures is almost always given in combination with either volatile or intravenous anesthetics. The modifying influence of such interventions has been studied clinically and in experimental settings; the reported findings, however, are inconsistent. The present study compares the cerebrovascular effects of MAC equivalent concentrations of isoflurane alone and isoflurane plus nitrous oxide. Twenty lumbar laminectomy patients randomized either to receive isoflurane or isoflurane plus nitrous oxide were investigated over a dose range from 0.5 to 1.5 MAC. A transcranial Doppler (TCD) ultrasonography device was used to measure cerebral blood flow velocity (CBFV) in the right middle cerebral artery (MCA) as an index of anesthetic-induced alterations in cerebral blood flow (CBF). A small but marginally significant decrease in CBFV at 1 MAC and no change at 1.5 MAC occurred in the isoflurane anesthetized patients. In contrast, a small but significant increase in CBFV at 1 MAC and a very significant increase at 1.5 MAC occurred in the isoflurane plus nitrous oxide anesthetized patients. Nitrous oxide added to an isoflurane anesthetic regimen is concluded to be a potent vasodilator. In addition, the vasodilating effects of nitrous oxide were not uniform; they progressively increased with an increasing isoflurane concentration.
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Affiliation(s)
- S Strebel
- Department of Anaesthesia, University of Basel/Kantonsspital, Switzerland
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Van Aken H, Van Hemelrijck J, Verhaegen M. [Anesthetics: total intravenous anesthesia or inhalation anesthesia in neurosurgery]. ANNALES FRANCAISES D'ANESTHESIE ET DE REANIMATION 1995; 14:56-69. [PMID: 7677289 DOI: 10.1016/s0750-7658(05)80152-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In this review article the pro's and contra's of the use of either inhalational or intravenous anaesthetics for neurosurgical procedures are discussed. The objective is to stimulate thoughts concerning controversial subjects, rather than to resolve issues. It is much less complicated to approach the practice of neuroanaesthesia with a few straight forward "rules" based on laboratory measurements (such as intravenous drugs are good because they reduce CBF and ICP, whereas inhalational agents are bad because they increase CBF and ICP). It should also be noted that whereas statements about potential detrimental or beneficial effects of different anaesthetic agents are relatively common, there is a dearth of well-designed prospective studies of sufficient power to substantiate the outcome advantages or disadvantages. The choice of an anaesthetic should include more than just a consideration of the potential intracranial effects of a drug: it should also include experience with a drug and, more important a consideration of the patient as a whole.
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Affiliation(s)
- H Van Aken
- Department of Anesthesiology, Universitaire Ziekenhuizen, Katholieke Universiteit Leuven, Belgium
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Nonvasodilating Vasodilating Anesthetics? Anesth Analg 1995. [DOI: 10.1097/00000539-199501000-00044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lam AM. Nonvasodilating Vasodilating Anesthetics? Anesth Analg 1995. [DOI: 10.1213/00000539-199501000-00044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
The literature concerning the interactions between volatile anaesthetics, nitrous oxide and other compounds is reviewed. The majority are well known and most can be managed by careful dosage of the anaesthetics. The following interactions should be stressed since these are less predictable or potentially fatal. Of the cardiovascular drugs mainly the Ca++ channel blockers require attention. The volatile anaesthetics act synergistically with these drugs on the inhibition of cardiac conduction and may induce cardiac arrest. Aminoglycoside therapy should prompt an alternative to enflurane because of increased nephrotoxicity with this combination. Thiopentone induction makes the dog heart more susceptible to arrhythmias, especially during anaesthesia with volatile anaesthetics. Probably pentobarbitone, etomidate or a benzodiazepine should be preferred as an alternative to thiopentone when the use of adrenergic drugs peroperatively is anticipated. Nitrous oxide augments the sequelae after coronary air emboli and impaired cerebral perfusion in animals. The necessity of this drug should therefore be considered when anaesthetizing patients undergoing open heart surgery and patients with severe carotid or cerebral arteriosclerosis.
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Affiliation(s)
- L Q Christensen
- Department of Infectious Diseases M, Rigshospitalet, University of Copenhagen, Denmark
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