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Mirra A, Gamez Maidanskaia E, Carmo LP, Levionnois O, Spadavecchia C. How is depth of anaesthesia assessed in experimental pigs? A scoping review. PLoS One 2023; 18:e0283511. [PMID: 36952576 PMCID: PMC10035875 DOI: 10.1371/journal.pone.0283511] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 03/09/2023] [Indexed: 03/25/2023] Open
Abstract
BACKGROUND Despite the large number of pigs involved in translational studies, no gold standard depth of anaesthesia indicators are available. We undertook a scoping review to investigate and summarize the evidence that sustains or contradicts the use of depth of anaesthesia indicators in this species. METHODS Medline, Embase and CAB abstract were searched up to September 22nd 2022. No limits were set for time, language and study type. Only original articles of in vivo studies using pigs or minipigs undergoing general anaesthesia were included. The depth of anaesthesia indicators reported in the selected papers were divided in two categories: A, indicators purposely investigated as method to assess depth of anaesthesia; B, indicators reported but not investigated as method to assess depth of anaesthesia. RESULTS Out of 13792 papers found, 105 were included after the screening process. Category A: 17 depth of anaesthesia indicators were found in 19 papers. Studies were conducted using inhalant anaesthetics as the main anaesthetic agent in the majority of the cases (13/19 = 68.4%), while 3/19 (15.8%) used propofol. The most investigated depth of anaesthesia indicators were bispectral index (8/19 = 42.1%) and spectral edge frequency 95% (5/19 = 26.3%). Contrasting results about the specific usefulness of each depth of anaesthesia indicators were reported. Category B: 23 depth of anaesthesia indicators were found in 92 papers. The most reported depth of anaesthesia indicators were: motor response following a stimulus (37/92 = 40.2%), depth of anaesthesia scores (21/92 = 23.3%), bispectral index (16/92 = 17.8%) and spectral edge frequency 95% (9/92 = 9.8%). CONCLUSION Results highlight the lack of scientifically valid and reliable indicators to ensure adequate depth of anaesthesia in pigs.
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Affiliation(s)
- Alessandro Mirra
- Anaesthesiology and Pain Therapy Section, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Ekaterina Gamez Maidanskaia
- Anaesthesiology and Pain Therapy Section, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Luís Pedro Carmo
- Department of Clinical Research und Public Health (DCR-VPH), Vetsuisse Faculty, Veterinary Public Health Institute, University of Bern, Bern, Switzerland
- Norwegian Veterinary Institute, Ås, Norway
| | - Olivier Levionnois
- Anaesthesiology and Pain Therapy Section, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Claudia Spadavecchia
- Anaesthesiology and Pain Therapy Section, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland
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Van Hese L, Al tmimi L, Devroe S, Sanders R, Fieuws S, Rex S. Neuroprotective properties of xenon in different types of CNS injury. Br J Anaesth 2018; 121:1365-1368. [DOI: 10.1016/j.bja.2018.08.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/23/2018] [Accepted: 08/27/2018] [Indexed: 01/13/2023] Open
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Stuth EAE, Stucke AG, Zuperku EJ. Effects of anesthetics, sedatives, and opioids on ventilatory control. Compr Physiol 2013; 2:2281-367. [PMID: 23720250 DOI: 10.1002/cphy.c100061] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This article provides a comprehensive, up to date summary of the effects of volatile, gaseous, and intravenous anesthetics and opioid agonists on ventilatory control. Emphasis is placed on data from human studies. Further mechanistic insights are provided by in vivo and in vitro data from other mammalian species. The focus is on the effects of clinically relevant agonist concentrations and studies using pharmacological, that is, supraclinical agonist concentrations are de-emphasized or excluded.
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Affiliation(s)
- Eckehard A E Stuth
- Medical College of Wisconsin, Anesthesia Research Service, Zablocki VA Medical Center, Milwaukee, Wisconsin, USA.
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LIU X, DINGLEY J, ELSTAD M, SCULL-BROWN E, STEEN PA, THORESEN M. Minimum alveolar concentration (MAC) for sevoflurane and xenon at normothermia and hypothermia in newborn pigs. Acta Anaesthesiol Scand 2013; 57:646-53. [PMID: 23316707 DOI: 10.1111/aas.12055] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2012] [Indexed: 12/21/2022]
Abstract
BACKGROUND Neuroprotection from therapeutic hypothermia increases when combined with the anaesthetic gas xenon in animal studies. A clinical feasibility study of the combined treatment has been successfully undertaken in asphyxiated human term newborns. It is unknown whether xenon alone would be sufficient for sedation during hypothermia eliminating or reducing the need for other sedative or analgesic infusions in ventilated sick infants. Minimum alveolar concentration (MAC) of xenon is unknown in any neonatal species. METHODS Eight newborn pigs were anaesthetised with sevoflurane alone and then sevoflurane plus xenon at two temperatures. Pigs were randomised to start at either 38.5°C or 33.5°C. MAC for sevoflurane was determined using the claw clamp technique at the preset body temperature. For xenon MAC determination, a background of 0.5 MAC sevoflurane was used, and 60% xenon added to the gas mixture. The relationship between sevoflurane and xenon MAC is assumed to be additive. Xenon concentrations were changed in 5% steps until a positive clamp reaction was noted. Pigs' temperature was changed to the second target, and two MAC determinations for sevoflurane and 0.5 MAC sevoflurane plus xenon were repeated. RESULTS MAC for sevoflurane was 4.1% [95% confidence interval (CI): 3.65-4.50] at 38.5°C and 3.05% (CI: 2.63-3.48) at 33.5°C, a significant reduction. MAC for xenon was 120% at 38.5°C and 116% at 33.5°C, not different. CONCLUSION In newborn swine sevoflurane, MAC was temperature dependent, while xenon MAC was independent of temperature. There was large individual variability in xenon MAC, from 60% to 120%.
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Affiliation(s)
- X. LIU
- Neonatal Neuroscience; School of Clinical Sciences; University of Bristol; Bristol; UK
| | - J. DINGLEY
- Anesthetics; Swansea Medical School; University of Swansea; Swansea; UK
| | - M. ELSTAD
- Department of Physiology; Institute of Basic Medical Sciences; University of Oslo; Oslo; Norway
| | - E. SCULL-BROWN
- Neonatal Neuroscience; School of Clinical Sciences; University of Bristol; Bristol; UK
| | - P. A. STEEN
- Clinic for Emergencies and Critical Care; University of Oslo and Oslo University Hospital; Norway
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A xenon recirculating ventilator for the newborn piglet: developing clinical applications of xenon for neonates. Eur J Anaesthesiol 2013; 29:577-85. [PMID: 22922476 DOI: 10.1097/eja.0b013e3283583c4b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
CONTEXT The clinical applications of xenon for the neonate include both anaesthesia and neuroprotection. However, due to the limited natural availability of xenon, special equipment is required to administer and recapture the gas to develop xenon as a therapeutic agent. OBJECTIVE In order to test the xenon recirculating ventilator for the application of neuroprotection in a preclinical trial, our primary objective was to test the efficiency, reliability and safety of administering 50% xenon for 24 h in hypoxic ischaemic piglets. DESIGN A prospective observational study. SETTING Institute for Women's Health, University College London, January 2008 to March 2008. ANIMALS Four anaesthetised male piglets, less than 24 h old, underwent a global hypoxic ischaemic insult for approximately 25 min prior to switching to the xenon recirculating ventilator. INTERVENTION Between 2 and 26 h after hypoxic ischaemia, anaesthetised piglets were administered a mixture of 50% xenon, air, oxygen and isoflurane. MAIN OUTCOME MEASURES The primary outcome measure was blood gas PaCO2 (kPa) and secondary outcome measure was xenon gas use (l h), over the 24-h duration of xenon administration. RESULTS The xenon recirculating ventilator provided effective ventilation, automated control of xenon/air gas mixtures, and stable blood gas PaCO2 (4.5 to 6.3 kPa) for 24 h of ventilation with the xenon recirculating ventilator. Total xenon use was minimal at approximately 0.6 l h at a cost of approximately &OV0556;8 h. Additional features included an isoflurane scavenger and bellows height alarm. CONCLUSION Stable gas delivery to a piglet with minimal xenon loss and analogue circuitry made the xenon recirculating ventilator easy to use and it could be modified for other large animals and noble gas mixtures. The technologies, safety and efficiency of xenon delivery in this preclinical system have been taken forward in the development of neonatal ventilators for clinical use in phase II clinical trials for xenon-augmented hypothermia and for xenon anaesthesia.
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Hein M, Baumert JH, Roehl AB, Pasch L, Schnoor J, Coburn M, Rossaint R. Xenon alters right ventricular function. Acta Anaesthesiol Scand 2008; 52:1056-63. [PMID: 18840104 DOI: 10.1111/j.1399-6576.2008.01696.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND In contrast to other volatile anesthetics, xenon produces less cardiovascular depression with fewer fluctuations of various hemodynamic parameters, but reduces cardiac output (CO) in vivo. Besides an increase in left ventricular afterload and reduction of heart rate, an impairment of the right ventricular function might be an additional pathophysiological mechanism for the reduction of CO. Therefore, we used an animal model to study the effects of xenon as a supplemental anesthetic on right ventricular function, especially right ventricular afterload. METHODS Right ventricular function was monitored with a volumetric pulmonary artery catheter in 11 pigs during general anesthesia with thiopental. Six animals received additional 70% (volume) xenon (equivalent to 0.55 MAC minimum alveolar concentration). Parameters for systolic function, afterload, and preload were calculated at baseline and during 50 min of xenon application, and in a corresponding control group. Significant differences were detected by multivariate analyses of variance for repeated measures. RESULTS Xenon reduced CO on average by 30% and increased pulmonary arterial elastance by 60%, which led to a reduction of the right ventricular ejection fraction by 25%. Whereas right ventricular preload remained stable, maximal slope of pulmonary artery pressure and the right ventricular elastance increased. No effect on the ratio of stroke work and end-diastolic volume was found. CONCLUSION The reduction in CO during xenon anesthesia was partly due to an impairment of the right ventricular function, mainly caused by an increased afterload, without an impairment of systolic ventricular function.
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Affiliation(s)
- M Hein
- Department of Anesthesiology, University Hospital of Aken, Aachen, Germany.
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Eger EI, Tang M, Liao M, Laster MJ, Solt K, Flood P, Jenkins A, Raines D, Hendrickx JF, Shafer SL, Yasumasa T, Sonner JM. Inhaled anesthetics do not combine to produce synergistic effects regarding minimum alveolar anesthetic concentration in rats. Anesth Analg 2008; 107:479-85. [PMID: 18633026 DOI: 10.1213/01.ane.0000295805.70887.65] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND We hypothesized that pairs of inhaled anesthetics having divergent potencies [one acting weakly at minimum alveolar anesthetic concentration (MAC); one acting strongly at MAC] on specific receptors/channels might act synergistically, and that such deviations from additivity would support the notion that anesthetics act on multiple sites to produce anesthesia. METHODS Accordingly, we studied the additivity of MAC for 11 anesthetic pairs divergently (one weakly, one strongly) affecting a specific receptor/channel at MAC. By "divergently," we usually meant that at MAC the more strongly acting anesthetic enhanced or blocked the in vitro receptor or channel at least twice (and usually more) as much as did the weakly acting anesthetic. The receptors/channels included: TREK-1 and TASK-3 potassium channels; and gamma-aminobutyric acid type A, glycine, N-methyl-D-aspartic acid, and acetylcholine receptors. We also studied the additivity of cyclopropane-benzene because the N-methyl-D-aspartic acid blocker MK-801 had divergent effects on the MACs of these anesthetics. We also studied four pairs that included nitrous oxide because nitrous oxide had been reported to produce infraadditivity (antagonism) when combined with isoflurane. RESULTS All combinations produced a result within 10% of that which would be predicted by additivity except for the combination of isoflurane with nitrous oxide where infraadditivity was found. CONCLUSIONS Such results are consistent with the notion that inhaled anesthetics act on a single site to produce immobility in the face of noxious stimulation.
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Affiliation(s)
- Edmond I Eger
- Department of Anesthesia, S-455, University of California, San Francisco, CA 94143-0464, USA.
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Hendrickx JFA, Eger EI, Sonner JM, Shafer SL. Is Synergy the Rule? A Review of Anesthetic Interactions Producing Hypnosis and Immobility. Anesth Analg 2008; 107:494-506. [PMID: 18633028 DOI: 10.1213/ane.0b013e31817b859e] [Citation(s) in RCA: 185] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Abstract
Of all the inert gases, only xenon has considerable anaesthetic properties under normobaric conditions. Its very low blood/gas partition coefficient makes induction of and emergence from anaesthesia more rapid compared with other inhalational anaesthetics. In experimental and clinical studies the safety and efficiency of xenon as an anaesthetic has been demonstrated. Xenon causes several physiological changes, which mediate protection of the brain or myocardium. The use of xenon might therefore be beneficial in certain clinical situations, as in patients at high risk for neurological or cardiac damage.
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Affiliation(s)
- Benedikt Preckel
- Department of Anaesthesiology, Dusseldorf University Hospital, P.O. Box 10 10 07, D-40001 Düsseldorf, Germany.
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Baumert JH, Hecker KE, Hein M, Reyle-Hahn M, Horn NA, Rossaint R. Effects of xenon anaesthesia on the circulatory response to hypoventilation. Br J Anaesth 2005; 95:166-71. [PMID: 15908452 DOI: 10.1093/bja/aei153] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Circulatory response to hypoventilation is aimed at eliminating carbon dioxide and maintaining oxygen delivery (DO(2)) by increasing cardiac output (CO). The hypothesis that this increase is more pronounced with xenon than with isoflurane anaesthesia was tested in pigs. METHODS Twenty pigs received anaesthesia with xenon 0.55 MAC/remifentanil 0.5 microg kg(-1) min(-1) (group X, n=10) or isoflurane 0.55 MAC/remifentanil 0.5 microg kg(-1)min(-1) (group I, n=10). CO, heart rate (HR), mean arterial pressure (MAP) and left ventricular fractional area change (FAC) were measured at baseline, after 5 and 15 min of hypoventilation and after 5, 15 and 30 min of restored ventilation. RESULTS CO increased by 10-20% with both anaesthetics, with an equivalent rise in HR, maintaining DO(2) in spite of a 20% reduction in arterial oxygen content. Decreased left ventricular (LV) afterload during hypoventilation increased FAC, and this was more marked with xenon (0.60-0.66, P<0.05 compared with baseline and isoflurane). This difference is attributed to negative inotropic effects of isoflurane. Increased pulmonary vascular resistance during hypoventilation was found with both anaesthetics. CONCLUSION The cardiovascular effects observed in this model of moderate hypoventilation were sufficient to maintain DO(2). Although the haemodynamic response appeared more pronounced with xenon, differences were not clinically relevant. An increase in FAC with xenon is attributed to its lack of negative inotropic effects.
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Affiliation(s)
- J-H Baumert
- Anaesthesiology Clinic, Universitaetsklinikum Aachen, Germany.
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Baumert JH, Hecker KE, Hein M, Reyle-Hahn SM, Horn NA, Rossaint R. Haemodynamic effects of haemorrhage during xenon anaesthesia in pigs. Br J Anaesth 2005; 94:727-32. [PMID: 15805140 DOI: 10.1093/bja/aei127] [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: 12/24/2022] Open
Abstract
BACKGROUND It was hypothesized that xenon would stabilize mean arterial pressure (MAP) in haemorrhagic shock, recovery, and volume resuscitation, because a higher MAP has been observed with xenon, when compared with isoflurane anaesthesia. The responses to haemorrhage and subsequent volume replacement were therefore compared between xenon and isoflurane anaesthesia, in pigs. METHODS Pigs were randomized to anaesthesia with xenon 0.55 MAC (group Xe, n=9) or isoflurane 0.55 MAC (group Iso, n=9), each with remifentanil 0.5 microg kg(-1) min(-1). MAP, heart rate, cardiac output (CO), and left ventricular fractional area change (FAC) were collected at control (1), after haemorrhage (20 ml kg(-1)) (2), after 10 min of recovery (3), after volume replacement (4), and 30 min later (5). Data were analysed by two-way repeated measures anova. RESULTS Blood loss decreased MAP (Xe: 103 [21] to 53 [24] mm Hg; Iso: 92 [18] to 55 [14] mm Hg) and CO (Xe: 4.1 [0.8] to 2.6 [0.5] litre min(-1); Iso: 5.1 [1.1] to 3.8 [1.2] litre min(-1)), in spite of significant tachycardia. MAP and CO recovered to about 75% of control, and subsequent volume replacement completely reversed symptoms in both groups, but increased FAC only with xenon. CONCLUSION Haemodynamic response to acute haemorrhage appeared faster with xenon/remifentanil than with isoflurane/remifentanil anaesthesia. In particular MAP decrease and short-term recovery were more marked with xenon (P<0.02). In the xenon group, volume replacement increased FAC compared with control and isoflurane (P<0.02).
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Affiliation(s)
- J-H Baumert
- Klinik fuer Anaesthesiologie, Universitaetsklinikum Aaachen, Pauwelsstrasse 30, D-52074 Aachen, Germany.
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Schmidt M, Marx T, Armbruster S, Reinelt H, Schirmer U. Effect of Xenon on elevated intracranial pressure as compared with nitrous oxide and total intravenous anesthesia in pigs. Acta Anaesthesiol Scand 2005; 49:494-501. [PMID: 15777297 DOI: 10.1111/j.1399-6576.2005.00609.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Xenon in low concentrations has been investigated in neuroradiology to measure cerebral blood flow (CBF). Several reports have suggested that inhalation of Xenon might increase intracranial pressure (ICP) by increasing the cerebral blood flow and blood volume, raising concerns about using Xenon as an anesthetic in higher concentrations for head-injured patients. A porcine study is presented in which the effects of inhaled 75% Xenon on elevated ICP, cerebral perfusion pressure and the efficacy of hyperventilation for ICP treatment were compared with nitrous oxide anesthesia and total intravenous anesthesia (TIVA). METHODS Twenty-one pentobarbital-anesthetized pigs (age: 12-16 weeks) were randomly assigned to three groups to receive either 4 h of Xenon-oxygen ventilation, nitrous oxide-oxygen ventilation or air-oxygen (75%/25%) ventilation, respectively. After instrumentation for parenchymal ICP measurement and ICP manipulation, an epidurally placed 6-F balloon catheter was inflated until a target ICP of 20 mmHg was achieved. After 4 h of anesthesia hyper- and hypoventilation maneuvers were performed and consecutive ICP and CBF changes were investigated. RESULTS Intracranial pressure and CBF increased significantly in the nitrous oxide group as compared with the controls. There was no increase of ICP or CBF in the Xenon or control group. Intracranial pressure changed in all three groups corresponding to hyper- and hypoventilation. CONCLUSIONS During Xenon anesthesia, elevated ICP is not increased further and is partially reversible by hyperventilation. Our study suggests that inhalation of 75% Xenon seems not to be contraindicated in patients with elevated ICP.
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Affiliation(s)
- M Schmidt
- Department Cardiac Anesthesia, University of Ulm, Ulm, Germany.
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Schwarzkopf K, Schreiber T, Gaser E, Preussler NP, Hueter L, Schubert H, Rek H, Karzai W. The effects of xenon or nitrous oxide supplementation on systemic oxygenation and pulmonary perfusion during one-lung ventilation in pigs. Anesth Analg 2005; 100:335-339. [PMID: 15673852 DOI: 10.1213/01.ane.0000142118.84049.80] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
During experimental one-lung ventilation (OLV), the type of anesthesia may alter systemic hemodynamics, lung perfusion, and oxygenation. We studied whether xenon (Xe) or nitrous oxide (N(2)O) added to propofol anesthesia would affect oxygenation, lung perfusion, and systemic and pulmonary hemodynamics during OLV in a pig model. Nine pigs were anesthetized, tracheally intubated, and mechanically ventilated. After placement of arterial and pulmonary artery catheters, a left-sided double-lumen tube was placed via tracheotomy. IV anesthesia with propofol was supplemented in random order with N(2)O/O(2) 60:40 or Xe/O(2) 60:40 or N(2)/O(2) 60:40. All measurements were made after stabilization at each concentration. Differential lung perfusion was measured with colored microspheres. Oxygenation (Pao(2): 90 +/- 17, 95 +/- 20, and 94 +/- 20 mm Hg for N(2)/O(2), N(2)O/O(2), and Xe/O(2)) and left lung perfusion (16% +/- 5%, 14% +/- 6%, and 18.8% for N(2)/O(2), N(2)O/O(2), and Xe/O(2)) during OLV did not differ among the 3 groups. However, mean arterial blood pressure (78 +/- 25, 62 +/- 23, and 66 +/- 23 mm Hg for N(2)/O(2), N(2)O/O(2), and Xe/O(2)) and mixed venous saturation (55% +/- 12%, 48% +/- 12%, and 50% +/- 12% for N(2)/O(2), N(2)O/O(2), and Xe/O(2)) were reduced during N(2)O/O(2) as compared with the control group (N(2)/O(2)). Supplementation of IV anesthesia with Xe or N(2)O does not impair oxygenation nor alter lung perfusion during experimental OLV.
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Affiliation(s)
- Konrad Schwarzkopf
- *Department of Anesthesiology and Intensive Care Medicine and †Institute for Experimental Animals, University of Jena; and ‡Department of Anesthesiology and Intensive Care Medicine, Zentralklinik Bad Berka, Germany
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Vagts DA, Hecker K, Iber T, Roesner JP, Spee A, Otto B, Rossaint R, Nöldge-Schomburg GFE. Effects of xenon anaesthesia on intestinal oxygenation in acutely instrumented pigs. Br J Anaesth 2004; 93:833-41. [PMID: 15465844 DOI: 10.1093/bja/aeh271] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Xenon is a narcotic gas that might be able to replace volatile anaesthetics or nitrous oxide due to its favourable pharmacological properties, such as providing haemodynamic stability. Intestinal oxygenation is affected by most volatile anaesthetics as a result of cardiodepressive effects. Reducing oxygenation of the gut might be a factor leading to perioperative organ dysfunction. This animal study was designed to assess the effects of xenon on intestinal oxygenation. METHODS After ethical approval, 24 anaesthetized, acutely instrumented pigs were randomly assigned to three groups: nine animals received xenon anaesthesia with inspiratory concentrations of 0, 20, 50 and 65% in addition to their basic i.v. anaesthesia, nine animals served as a study control group, and five animals were used to assess model stability. Measurement of systemic and regional haemodynamic and oxygenation parameters was made 30 min after changing the xenon concentration. RESULTS Xenon elicited dose-dependent systemic haemodynamic changes: heart rate and cardiac output decreased by 30%, while mean arterial pressure was stable. Superior mesenteric artery blood flow was lower in the xenon group. Vascular resistance of the superior mesenteric artery increased. The small intestinal oxygen supply decreased with increasing xenon concentration; the mucosal tissue oxygen partial pressure decreased but did not reach hypoxic (<5 mm Hg) values. Serosal tissue oxygen partial pressure was maintained. CONCLUSIONS Xenon, in addition to basic i.v. anaesthesia, elicited a decrease in cardiac output and maintained mean arterial pressure. Intestinal oxygenation was maintained, although regional macrohaemodynamic perfusion decreased. Xenon does not impair intestinal oxygenation under physiological conditions.
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Affiliation(s)
- D A Vagts
- Klinik und Poliklinik für Anästhesiologie und Intensivtherapie, Universität Rostock, Schillingallee 35, D-18055 Rostock, Germany.
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