1
|
Chalifoux N, Ko T, Slovis J, Spelde A, Kilbaugh T, Mavroudis CD. Cerebral Autoregulation: A Target for Improving Neurological Outcomes in Extracorporeal Life Support. Neurocrit Care 2024:10.1007/s12028-024-02002-5. [PMID: 38811513 DOI: 10.1007/s12028-024-02002-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 04/18/2024] [Indexed: 05/31/2024]
Abstract
Despite improvements in survival after illnesses requiring extracorporeal life support, cerebral injury continues to hinder successful outcomes. Cerebral autoregulation (CA) is an innate protective mechanism that maintains constant cerebral blood flow in the face of varying systemic blood pressure. However, it is impaired in certain disease states and, potentially, following initiation of extracorporeal circulatory support. In this review, we first discuss patient-related factors pertaining to venovenous and venoarterial extracorporeal membrane oxygenation (ECMO) and their potential role in CA impairment. Next, we examine factors intrinsic to ECMO that may affect CA, such as cannulation, changes in pulsatility, the inflammatory and adaptive immune response, intracranial hemorrhage, and ischemic stroke, in addition to ECMO management factors, such as oxygenation, ventilation, flow rates, and blood pressure management. We highlight potential mechanisms that lead to disruption of CA in both pediatric and adult populations, the challenges of measuring CA in these patients, and potential associations with neurological outcome. Altogether, we discuss individualized CA monitoring as a potential target for improving neurological outcomes in extracorporeal life support.
Collapse
Affiliation(s)
- Nolan Chalifoux
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Department of Anesthesiology and Critical Care Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Tiffany Ko
- Department of Anesthesiology and Critical Care Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Julia Slovis
- Department of Anesthesiology and Critical Care Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Audrey Spelde
- Department of Anesthesiology and Critical Care Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Todd Kilbaugh
- Department of Anesthesiology and Critical Care Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Constantine D Mavroudis
- Division of Cardiothoracic Surgery, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| |
Collapse
|
2
|
Provitera L, Amelio GS, Tripodi M, Raffaeli G, Macchini F, Amodeo I, Gulden S, Cortesi V, Manzoni F, Cervellini G, Tomaselli A, Zuanetti G, Lonati C, Battistin M, Kamel S, Parente V, Pravatà V, Villa S, Villamor E, Mosca F, Cavallaro G. Veno-Arterial Extracorporeal Membrane Oxygenation (ECMO) Impairs Bradykinin-Induced Relaxation in Neonatal Porcine Coronary Arteries. Biomedicines 2022; 10:biomedicines10092083. [PMID: 36140183 PMCID: PMC9495700 DOI: 10.3390/biomedicines10092083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/18/2022] [Accepted: 08/19/2022] [Indexed: 11/26/2022] Open
Abstract
Extracorporeal membrane oxygenation (ECMO) is a lifesaving support for respiratory and cardiovascular failure. However, ECMO induces a systemic inflammatory response syndrome that can lead to various complications, including endothelial dysfunction in the cerebral circulation. We aimed to investigate whether ECMO-associated endothelial dysfunction also affected coronary circulation. Ten-day-old piglets were randomized to undergo either 8 h of veno-arterial ECMO (n = 5) or no treatment (Control, n = 5). Hearts were harvested and coronary arteries were dissected and mounted as 3 mm rings in organ baths for isometric force measurement. Following precontraction with the thromboxane prostanoid (TP) receptor agonist U46619, concentration−response curves to the endothelium-dependent vasodilator bradykinin (BK) and the nitric oxide (NO) donor (endothelium-independent vasodilator) sodium nitroprusside (SNP) were performed. Relaxation to BK was studied in the absence or presence of the NO synthase inhibitor Nω-nitro-L-arginine methyl ester HCl (L-NAME). U46619-induced contraction and SNP-induced relaxation were similar in control and ECMO coronary arteries. However, BK-induced relaxation was significantly impaired in the ECMO group (30.4 ± 2.2% vs. 59.2 ± 2.1%; p < 0.0001). When L-NAME was present, no differences in BK-mediated relaxation were observed between the control and ECMO groups. Taken together, our data suggest that ECMO exposure impairs endothelium-derived NO-mediated coronary relaxation. However, there is a NO-independent component in BK-induced relaxation that remains unaffected by ECMO. In addition, the smooth muscle cell response to exogenous NO is not altered by ECMO exposure.
Collapse
Affiliation(s)
- Livia Provitera
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Giacomo S. Amelio
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Matteo Tripodi
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Genny Raffaeli
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
- Correspondence:
| | - Francesco Macchini
- Department of Pediatric Surgery, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Department of Pediatric Surgery, ASST Grande Ospedale Metropolitano (GOM) Niguarda, 20162 Milan, Italy
| | - Ilaria Amodeo
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Silvia Gulden
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Valeria Cortesi
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
| | - Francesca Manzoni
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
| | - Gaia Cervellini
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
| | - Andrea Tomaselli
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
| | - Gabriele Zuanetti
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
| | - Caterina Lonati
- Center for Preclinical Investigation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Michele Battistin
- Center for Preclinical Investigation, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Shady Kamel
- Betamed Perfusion Service, 00192 Rome, Italy
| | | | - Valentina Pravatà
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Stefania Villa
- Transfusion Center and Blood Component Bank of Rare Groups, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Eduardo Villamor
- Department of Pediatrics, Maastricht University Medical Center (MUMC+), School for Oncology and Reproduction (GROW), University of Maastricht, 6229 Maastricht, The Netherlands
| | - Fabio Mosca
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
| | - Giacomo Cavallaro
- Neonatal Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| |
Collapse
|
3
|
Håheim B, Kondratiev T, Dietrichs ES, Tveita T. Comparison Between Two Pharmacologic Strategies to Alleviate Rewarming Shock: Vasodilation vs. Inodilation. Front Med (Lausanne) 2020; 7:566388. [PMID: 33282886 PMCID: PMC7689197 DOI: 10.3389/fmed.2020.566388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 10/05/2020] [Indexed: 11/13/2022] Open
Abstract
Rewarming from hypothermia is often challenged by coexisting cardiac dysfunction, depressed organ blood flow (OBF), and increased systemic vascular resistance. Previous research shows cardiovascular inotropic support and vasodilation during rewarming to elevate cardiac output (CO). The present study aims to compare the effects of inodilatation by levosimendan (LS) and vasodilation by nitroprusside (SNP) on OBF and global oxygen transport during rewarming from hypothermia. We used an in vivo experimental rat model of 4 h 15°C hypothermia and rewarming. A stable isotope-labeled microsphere technique was used to determine OBF. Cardiac and arterial pressures were monitored with fluid-filled pressure catheters, and CO was measured by thermodilution. Two groups were treated with either LS (n = 7) or SNP (n = 7) during the last hour of hypothermia and throughout rewarming. Two groups served as hypothermic (n = 7) and normothermic (n = 6) controls. All hypothermia groups had significantly reduced CO, oxygen delivery, and OBF after rewarming compared to their baseline values. After rewarming, LS had elevated CO significantly more than SNP (66.57 ± 5.6/+30% vs. 54.48 ± 5.2/+14%) compared to the control group (47.22 ± 3.9), but their ability to cause elevation of brain blood flow (BBF) was the same (0.554 ± 0.180/+81 vs. 0.535 ± 0.208/+75%) compared to the control group (0.305 ± 0.101). We interpret the vasodilator properties of LS and SNP to be the primary source to increase organ blood flow, superior to the increase in CO.
Collapse
Affiliation(s)
- Brage Håheim
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromsø, Norway
| | - Timofei Kondratiev
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromsø, Norway
| | - Erik Sveberg Dietrichs
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromsø, Norway.,Experimental and Clinical Pharmacology Research Group, Department of Medical Biology, UiT, The Arctic University of Norway, Tromsø, Norway
| | - Torkjel Tveita
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway
| |
Collapse
|
4
|
Chan B, Aneman A. A prospective, observational study of cerebrovascular autoregulation and its association with delirium following cardiac surgery. Anaesthesia 2018; 74:33-44. [DOI: 10.1111/anae.14457] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2018] [Indexed: 12/18/2022]
Affiliation(s)
- B. Chan
- Faculty of Medicine; University of New South Wales; Sydney NSW Australia
| | - A. Aneman
- Intensive Care Unit; Liverpool Hospital; Liverpool NSW Australia
| |
Collapse
|
5
|
Håheim B, Kondratiev T, Dietrichs ES, Tveita T. The beneficial hemodynamic effects of afterload reduction by sodium nitroprusside during rewarming from experimental hypothermia. Cryobiology 2017; 77:75-81. [PMID: 28479295 DOI: 10.1016/j.cryobiol.2017.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/02/2017] [Accepted: 05/03/2017] [Indexed: 01/13/2023]
Abstract
BACKGROUND Rewarming from hypothermia is associated with depressed cardiac function, known as hypothermia-induced cardiac dysfunction (HCD), and increased systemic vascular resistance (SVR). Previous studies on pharmacological treatment of HCD have demonstrated beneficial effects when using drugs with the combined effects; cardiac inotropic support and peripheral vasodilation. The presented study aims to investigate the isolated effects of arterial dilatation on cardiac functional variables during rewarming from hypothermia using sodium nitroprusside (SNP). METHODS We utilized a rat model designed to induce HCD following 4 h at 15 °C and rewarming. To study effects on left ventricular (LV) functional variables in response to afterload reduction by SNP during rewarming a conductance catheter was used. Index of LV contractility, preload recruitable stroke work (PRSW), was obtained with inferior vena cava occlusions at 37 °C before and after hypothermia. Pressure signals from a catheter in the left femoral artery was used to pharmacologically adjust SVR. RESULTS After rewarming both animal groups showed significant reduction in both SV and CO as a manifestation of HCD. However, compared to saline controls, SV and CO in SNP-treated animals increased significantly during rewarming in response to afterload reduction displayed as reduced SVR, mean arterial- and end-systolic pressures. The cardiac contractility variable PRSW was equally reduced after rewarming in both groups. CONCLUSION When rewarming the present model of HCD a significant increase in SVR takes place. In this context, pharmacologic intervention aimed at reducing SVR show clear positive results on CO and SV. However, a reduction in SVR alone is not sufficient to fully alleviate CO during HCD, and indicate the need of additional inotropic support.
Collapse
Affiliation(s)
- Brage Håheim
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Timofey Kondratiev
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, 9037 Tromsø, Norway.
| | - Erik Sveberg Dietrichs
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, 9037 Tromsø, Norway; Department of Research and Education, Norwegian Air Ambulance Foundation, 1441 Drøbak, Norway.
| | - Torkjel Tveita
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, 9037 Tromsø, Norway; Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, 9038 Tromsø, Norway.
| |
Collapse
|
6
|
Donndorf P, Kühn F, Vollmar B, Rösner J, Liebold A, Gierer P, Steinhoff G, Kaminski A. Comparing microvascular alterations during minimal extracorporeal circulation and conventional cardiopulmonary bypass in coronary artery bypass graft surgery: A prospective, randomized study. J Thorac Cardiovasc Surg 2012; 144:677-83. [DOI: 10.1016/j.jtcvs.2012.05.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 04/04/2012] [Accepted: 05/15/2012] [Indexed: 10/28/2022]
|
7
|
Real-time continuous neuromonitoring combines transcranial cerebral Doppler with near-infrared spectroscopy cerebral oxygen saturation during total aortic arch replacement procedure: a pilot study. ASAIO J 2012; 58:122-6. [PMID: 22370681 DOI: 10.1097/mat.0b013e318241abd3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The purpose of this investigation was to use combined transcranial cerebral Doppler (TCD) and near-infrared spectroscopy cerebral oxygen saturation (NIRS) during total aortic arch replacement (TAAR) to monitor middle cerebral artery blood flow velocity and regional cerebral oximetry (rSO(2)) changes to provide a clinical basis for protective measures that may decrease injury of the central nervous system. Consecutive 12 adult patients underwent deep hypothermic circulatory arrest (DHCA) and antegrade selective cerebral perfusion (ASCP) during TAAR. A TCD probe was placed at the temporal windows after induction of anesthesia and the NIRS probe placed on the forehead of patients to collect perioperative, intraoperative, and postoperative hemodynamic parameters, and cerebral blood flow (CBF) and rSO(2) during cardiopulmonary bypass (CPB). In this retrospective case series, all patients survived, and there were no postoperative neurologic complications. There was no significant correlation between the mean arterial pressure and rSO(2). The middle cerebral artery mean velocity (VmMCA) and rSO(2) were significantly correlated, and main pump flow significantly correlated with rSO(2). After ASCP, VmMCA, rSO(2), and venous oxygen saturation were significantly lower than before ASCP, but VmMCA and rSO(2) returned to pre-CPB levels postoperatively. After off pump, the flow of ASCP showed a significant positive correlation with VmMCA and rSO(2). During DHCA when ASCP flow was lower than 5 ml/kg/min, TCD could not detect the MCA blood flow signal. When the flow of ASCP was above keeping around 10 ml/kg/min, MCA CBF velocity was maintained and rSO(2) > 45%. The combination of TCD and NIRS can be effective in monitoring brain function during DHCA with ASCP and may provide a guide for decreasing brain injury during the TAAR procedure.
Collapse
|
8
|
Brady K, Joshi B, Zweifel C, Smielewski P, Czosnyka M, Easley RB, Hogue CW. Real-time continuous monitoring of cerebral blood flow autoregulation using near-infrared spectroscopy in patients undergoing cardiopulmonary bypass. Stroke 2010; 41:1951-6. [PMID: 20651274 DOI: 10.1161/strokeaha.109.575159] [Citation(s) in RCA: 254] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Individualizing mean arterial blood pressure targets to a patient's cerebral blood flow autoregulatory range might prevent brain ischemia for patients undergoing cardiopulmonary bypass (CPB). This study compares the accuracy of real-time cerebral blood flow autoregulation monitoring using near-infrared spectroscopy with that of transcranial Doppler. METHODS Sixty adult patients undergoing CPB had transcranial Doppler monitoring of middle cerebral artery blood flow velocity and near-infrared spectroscopy monitoring. The mean velocity index (Mx) was calculated as a moving, linear correlation coefficient between slow waves of middle cerebral artery blood flow velocity and mean arterial blood pressure. The cerebral oximetry index was calculated as a similar coefficient between slow waves of cerebral oximetry and mean arterial blood pressure. When cerebral blood flow is autoregulated, Mx and cerebral oximetry index vary around zero. Loss of autoregulation results in progressively more positive Mx and cerebral oximetry index. RESULTS Mx and cerebral oximetry index showed significant correlation (r=0.55, P<0.0001) and good agreement (bias, 0.08+/-0.18, 95% limits of agreement: -0.27 to 0.43) during CPB. Autoregulation was disturbed in this cohort during CPB (average Mx 0.38, 95% CI 0.34 to 0.43). The lower cerebral blood flow autoregulatory threshold (defined as incremental increase in Mx >0.45) during CPB ranged from 45 to 80 mm Hg. CONCLUSIONS Cerebral blood flow autoregulation can be monitored continuously with near-infrared spectroscopy in adult patients undergoing CPB. Real-time autoregulation monitoring may have a role in preventing injurious hypotension during CPB. Clinical Trials Registration- at www.clinicaltrials.gov (NCT00769691).
Collapse
Affiliation(s)
- Kenneth Brady
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Hospital, Baltimore, MD, USA.
| | | | | | | | | | | | | |
Collapse
|
9
|
Impaired autoregulation of cerebral blood flow during rewarming from hypothermic cardiopulmonary bypass and its potential association with stroke. Anesth Analg 2009; 110:321-8. [PMID: 20008083 DOI: 10.1213/ane.0b013e3181c6fd12] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Patient rewarming after hypothermic cardiopulmonary bypass (CPB) has been linked to brain injury after cardiac surgery. In this study, we evaluated whether cooling and then rewarming of body temperature during CPB in adult patients is associated with alterations in cerebral blood flow (CBF)-blood pressure autoregulation. METHODS One hundred twenty-seven adult patients undergoing CPB during cardiac surgery had transcranial Doppler monitoring of the right and left middle cerebral artery blood flow velocity. Eleven patients undergoing CPB who had arterial inflow maintained at >35 degrees C served as controls. The mean velocity index (Mx) was calculated as a moving, linear correlation coefficient between slow waves of middle cerebral artery blood flow velocity and mean arterial blood pressure. Intact CBF-blood pressure autoregulation is associated with an Mx that approaches 0. Impaired autoregulation results in an increasing Mx approaching 1.0. Comparisons of time-averaged Mx values were made between the following periods: before CPB (baseline), during the cooling and rewarming phases of CPB, and after CPB. The number of patients in each phase of CPB with an Mx >4.0, indicative of impaired CBF autoregulation, was determined. RESULTS During cooling, Mx (left, 0.29 +/- 0.18; right, 0.28 +/- 0.18 [mean +/- SD]) was greater than that at baseline (left, 0.17 +/- 0.21; right, 0.17 +/- 0.20; P <or= 0.0001). Mx increased during the rewarming phase of CPB (left, 0.40 +/- 0.19; right, 0.39 +/- 0.19) compared with baseline (P <or= 0.001) and the cooling phase (P <or= 0.0001), indicating impaired CBF autoregulation. After CPB, Mx (left, 0.27 +/- 0.20; right, 0.28 +/- 0.21) was higher than at baseline (left, P = 0.0004; right, P = 0.0003), no different than during the cooling phase, but lower than during rewarming (left, P <or= 0.0001; right, P <or= 0.0005). Forty-three patients (34%) had an Mx >or=0.4 during the cooling phase of CPB and 68 (53%) had an average Mx >or=0.4 during rewarming. Nine of the 11 warm controls had an average Mx >or=0.4 during the entire CPB period. There were 7 strokes and 1 TIA after surgery. All strokes were in patients with Mx >or= 0.4 during rewarming (P = 0.015). The unadjusted odds ratio for any neurologic event (stroke or transient ischemic attack) for patients with Mx >or= 0.4 during rewarming was 6.57 (95% confidence interval, 0.79 to 55.0, P < 0.08). CONCLUSIONS Hypothermic CPB is associated with abnormal CBF-blood pressure autoregulation that is worsened with rewarming. We found a high rate of strokes in patients with evidence of impaired CBF autoregulation. Whether a pressure-passive CBF state during rewarming is associated with risk for ischemic brain injury requires further investigation.
Collapse
|
10
|
Schmoker JD, Terrien C, McPartland KJ, Boyum J, Wellman GC, Trombley L, Kinne J. Cerebrovascular response to continuous cold perfusion and hypothermic circulatory arrest. J Thorac Cardiovasc Surg 2009; 137:459-64. [PMID: 19185170 DOI: 10.1016/j.jtcvs.2008.08.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 07/25/2008] [Accepted: 08/13/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Clinical and laboratory studies have documented changes in cerebrovascular resistance after hypothermic circulatory arrest, both with and without adjunctive cerebral perfusion modalities. This study was designed to clarify whether these changes are due to cerebral edema, resistance vessel abnormalities, or alterations in the cerebral microcirculation. METHODS Four mature swine underwent hypothermic circulatory arrest for 60 minutes, and 7 mature swine underwent cold cerebral perfusion for 60 minutes to simulate antegrade selective perfusion. All were rewarmed and weaned from cardiopulmonary bypass. Pial vascular diameter and reactivity were measured in vivo through a cranial window and ex vivo in an organ chamber; cerebral microvascular endothelium was studied in culture for release of vasoactive mediators. Cerebral water content was recorded. RESULTS Cold perfusion caused pial arteriole and venule constriction, whereas hypothermic circulatory arrest alone caused pial arteriole and venule dilatation. Cold perfusion caused a temporal loss of endothelium-dependent vasodilatation, most notably to bradykinin. Hypothermic circulatory arrest caused a loss of nitric oxide-mediated endothelium-dependent vasodilatation. Endothelium-independent vasoreactivity remained intact in both groups. Endothelial cells from the cold group had a vasoconstrictive secretory phenotype, whereas endothelial cells from the hypothermic circulatory arrest group had a vasodilatory phenotype. Cerebral water content was the same in both groups. CONCLUSION The increase in cerebrovascular resistance observed after cold cerebral perfusion is caused by resistance vessel constriction and may be promoted by an altered microcirculation. Hypothermic circulatory arrest alone is associated with endothelium-dependent vasoparesis. Both could contribute to cerebral injury in the early hours after operation.
Collapse
Affiliation(s)
- Joseph D Schmoker
- Department of Surgery, The University of Vermont College of Medicine, Burlington, VT, USA
| | | | | | | | | | | | | |
Collapse
|
11
|
Raja SG, Dreyfus GD. Current Status of Off-Pump Coronary Artery Bypass Surgery. Asian Cardiovasc Thorac Ann 2008; 16:164-78. [DOI: 10.1177/021849230801600220] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The expanding indications for angioplasty coupled with the successful short and mid-term results of randomized controlled trials of drug-eluting stents have already had an unquestionable impact on the practice of coronary revascularization operations. However, coronary artery bypass grafting remains a major mode of therapy for coronary artery disease. It is likely that surgery will continue to be preferred for more complex subsets and that surgeons will have to continue to maintain good results in patients with more complex problems. Concerns regarding morbidity associated with conventional surgical myocardial revascularization on cardiopulmonary bypass have led to a resurgence of interest in off-pump bypass surgery during the last decade, with the expectation that it would be safer if cardiopulmonary bypass could be avoided. This review summarizes the impact of off-pump bypass surgery in reducing the morbidity and mortality associated with conventional coronary artery bypass on cardiopulmonary bypass by evaluating the current best-available evidence from randomized controlled trials and meta-analyses comparing off-pump surgery with conventional bypass grafting.
Collapse
|
12
|
Meybohm P, Hoffmann G, Renner J, Boening A, Cavus E, Steinfath M, Scholz J, Bein B. Measurement of Blood Flow Index During Antegrade Selective Cerebral Perfusion with Near-Infrared Spectroscopy in Newborn Piglets. Anesth Analg 2008; 106:795-803, table of contents. [DOI: 10.1213/ane.0b013e31816173b4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
13
|
Yamazaki M, Aeba R, Yozu R, Kobayashi K. Use of hemoglobin vesicles during cardiopulmonary bypass priming prevents neurocognitive decline in rats. Circulation 2006; 114:I220-5. [PMID: 16820576 DOI: 10.1161/circulationaha.105.000562] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Homologous blood use is considered to be the gold standard for cardiopulmonary bypass (CPB) priming in infants despite exposure of the patient to potential cellular and humoral antigens. However, the use of hemoglobin vesicles (HbVs), artificial oxygen carriers that encapsulate a concentrated hemoglobin solution within phospholipid bilayer membranes, for CPB priming may prevent neurocognitive decline in infants. The goal of this study was to determine whether HbV use offsets hemodilution caused by patient/priming volume-mismatched CPB and thereby prevents the development of postoperative neurocognitive deficits. METHODS AND RESULTS CPB was established in 28 male Sprague-Dawley rats (age, 14 to 16 weeks; weight, 450 grams) after cannulation of the tail artery and right atrium. The animals were randomly assigned to 1 of 3 groups: sham surgery (n=9), HbV (-) prime (n=10), or HbV (+) prime (n=9). CPB was conducted for 90 minutes at 200 mL/kg per minute. The hematocrit during CPB was 10.0+/-1.2% in the HbV (+) prime group and 9.9+/-1.3% in the HbV (-) prime group (P=not significant). Learning and memory function were evaluated using 2 different maze tests (Maze-1 and Maze-2, in which the arrival times to the target were measured on the first, third, fifth, and seventh postoperative days). Learning and memory function were significantly better in the HbV (+) prime group than in the HbV (-) prime group (Maze-1, P=0.012; Maze-2, P=0.042); there was no difference between the HbV (+) prime and the sham surgery group. CONCLUSIONS The use of HbV for CPB priming may serve as a substitute for homologous blood to prevent the unacceptable hemodilution and contribute to maintenance of intact neurocognitive function.
Collapse
Affiliation(s)
- Masataka Yamazaki
- Division of Cardiovascular Surgery, Keio University, 35 Shinanomachi, Shinjuku, Tokyo, 160-8582, Japan
| | | | | | | |
Collapse
|
14
|
Ingyinn M, Rais-Bahrami K, Viswanathan M, Short BL. Altered cerebrovascular responses after exposure to venoarterial extracorporeal membrane oxygenation: role of the nitric oxide pathway. Pediatr Crit Care Med 2006; 7:368-73. [PMID: 16738508 DOI: 10.1097/01.pcc.0000225372.38460.12] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Previous studies in our laboratory on newborn lambs have shown cerebral autoregulation impairment after exposure to venoarterial extracorporeal membrane oxygenation (VA ECMO), with additional studies showing an altered cerebrovascular response to NG-nitro-L-arginine methyl ester in lamb cerebral vessels in this same model. OBJECTIVE To further study the mechanisms involved in altered cerebrovascular responses in vessels exposed to VA ECMO. DESIGN Prospective study. SETTING Research Animal Facility at Children's National Medical Center, Washington, DC. SUBJECT Newborn lambs, 1-7 days of age, 4.76 +/- 0.8 kg (n = 10). METHODS Animals randomly assigned two groups, control and VA ECMO, were anesthetized, ventilated, heparinized, and kept in a normal physiologic condition. Control animals were continued on ventilatory support, whereas animals in the VA ECMO groups were placed on VA ECMO, with bypass flows maintained between 120 and 200 mL x kg x min(-1) for 2.5 hrs. Isolated third-order branches of the middle cerebral arteries were studied for myotonic reactivity to increasing intraluminal pressure changes, response to acetylcholine, an endothelium-dependent vasodilator, 3-morpholinyl-sydnoneimine chloride, an endothelium-independent vasodilator, and serotonin, a direct vascular vasoconstrictor. Arterial caliber was monitored using video microscopy. RESULTS Myogenic constriction response was significantly decreased in the VA ECMO group compared with the control group (p = .03). Intraluminal acetylcholine caused concentration-dependent arterial dilation in the control group, whereas it resulted in vasoconstriction in the VA ECMO group (p = .008). There were no significant differences in dilation responses to 3-morpholinyl-sydnoneimine chloride and contractile responses to serotonin among the groups. CONCLUSION Cerebral arteries exposed to VA ECMO had impaired myogenic responses combined with altered endothelial function. The endothelial alteration seems to be mediated through the nitric oxide pathway, with recovery noted after addition of a nitric oxide donor. It can be postulated that these changes may reflect the mechanisms for the impairment of cerebral autoregulation previously reported in this lamb model.
Collapse
Affiliation(s)
- Ma Ingyinn
- Department of Neonatology, Children's National Medical Center, Washington, DC, USA
| | | | | | | |
Collapse
|
15
|
Abstract
Extracorporeal membrane oxygenation (ECMO) therapy has significantly improved outcome in the newborn, pediatric, and adult patient in respiratory and cardiac failure. Despite this therapy providing a life-saving technology, the morbidity in patients treated with ECMO therapy is primarily related to neurologic alterations and not pulmonary findings. For ECMO, this is not unexpected since most patients are being placed on ECMO support because of severe hypoxemia, with ECMO being considered a rescue therapy for respiratory failure in most instances. As use of ECMO becomes common place for infants and children in respiratory failure, our investigations into the outcome of these children must focus not only on survival versus nonsurvival, but on the causes of morbidity in this population. A further understanding of factors associated with morbidity may allow us to alter techniques used in extracorporeal life support (ECLS), hopefully to improve our long-term outcome in this population, while allowing us to expand use of these technologies to other populations such as the premature infant. This article will focus on the effect of ECMO on the brain, with the following chapter by Dr. Richard Jonas outlining the effect of cardiopulmonary bypass on the brain.
Collapse
Affiliation(s)
- Billie Lou Short
- Division of Neonatology, Children's National Medical Center, 111 Michigan Ave., NW, Washington, DC 20010, USA.
| |
Collapse
|
16
|
Iida H, Iida M, Ohata H, Nagase K, Dohi S. Hypothermia Attenuates the Vasodilator Effects of Dexmedetomidine on Pial Vessels in Rabbits In Vivo. Anesth Analg 2004; 98:477-482. [PMID: 14742391 DOI: 10.1213/01.ane.0000099365.30804.42] [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: 11/05/2022]
Abstract
UNLABELLED Studies have indicated that mild to moderate hypothermia or dexmedetomidine may have neuroprotective properties in animal models. In this study, we investigated the effects of hypothermia on dexmedetomidine-induced responses in cerebral vessels in anesthetized rabbits by using the cranial-window preparation. After instrumentation under pentobarbital anesthesia, 12 rabbits were assigned to 1 of 2 equal groups: normothermic (nasopharyngeal and intrawindow temperature, 38.5 degrees C-39.5 degrees C) or hypothermic (33.0 degrees C-34.0 degrees C). Each rabbit received three different concentrations (10(-7), 10(-5), and 10(-3) M) of dexmedetomidine under the window, and cerebral pial vessel diameters were measured in a sequential manner. In the normothermic group, dexmedetomidine induced a significant concentration-dependent dilation in both large and small arterioles. In the hypothermia group, dexmedetomidine produced a U-shaped dose-response in both large and small cerebral arterioles (concentration-related vasoconstriction at 10(-7) and 10(-5) M, but vasodilation at 10(-3) M). In cerebral venules, a similar pattern of results was obtained, but changes were generally smaller than in arterioles. In conclusion, topically applied dexmedetomidine induces concentration-dependent dilation in cerebral arterioles in normothermic rabbits anesthetized with pentobarbital, but mild to moderate hypothermia attenuates these responses, with smaller dexmedetomidine concentrations causing vasoconstriction. IMPLICATIONS In normothermic rabbits anesthetized with pentobarbital, topically applied dexmedetomidine induces a concentration-dependent dilation in both large and small cerebral arterioles, but mild to moderate hypothermia attenuates these responses.
Collapse
Affiliation(s)
- Hiroki Iida
- *Department of Anesthesiology and Critical Care Medicine and †Second Department of Internal Medicine and Anesthesiology, Gifu University School of Medicine, Gifu, Japan
| | | | | | | | | |
Collapse
|
17
|
Hoffman GM, Stuth EA, Jaquiss RD, Vanderwal PL, Staudt SR, Troshynski TJ, Ghanayem NS, Tweddell JS. Changes in cerebral and somatic oxygenation during stage 1 palliation of hypoplastic left heart syndrome using continuous regional cerebral perfusion. J Thorac Cardiovasc Surg 2004; 127:223-33. [PMID: 14752434 DOI: 10.1016/j.jtcvs.2003.08.021] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Stage 1 palliation of hypoplastic left heart syndrome requires the interruption of whole-body perfusion. Delayed reflow in the cerebral circulation secondary to prolonged elevation in vascular resistance occurs in neonates after deep hypothermic circulatory arrest. We examined relative changes in cerebral and somatic oxygenation with near-infrared spectroscopy while using a modified perfusion strategy that allowed continuous cerebral perfusion. METHODS Nine neonates undergoing stage 1 palliation for hypoplastic left heart syndrome had regional tissue oxygenation continuously measured by frontal cerebral and thoraco-lumbar (T10-L2) somatic (renal) reflectance oximetry probes (rSO(2), INVOS; Somanetics, Troy, Mich). Surgery was accomplished using cardiopulmonary bypass with whole-body cooling (18 degrees C-20 degrees C) and regional cerebral perfusion through the innominate artery at flow rates guided by estimated minimum flow requirements and measured rSO(2) during reconstruction of the aortic arch. Data were logged at 1-minute intervals and analyzed using repeated measures analysis of variance. RESULTS A total of 3176 minutes of data were analyzed. Prebypass cerebral rSO(2) was 65.4 +/- 8.9, and somatic rSO(2) was 58.9 +/- 12.4 (P <.001, cerebral vs somatic). During regional cerebral perfusion, cerebral rSO(2) was 80.7 +/- 8.6, and somatic rSO(2) was 41.4 +/- 7.1 (P <.001). Postbypass cerebral rSO(2) was 53.2 +/- 14.9, and somatic rSO(2) was 76.4 +/- 7.7 (P <.001). The risk of cerebral desaturation was significantly increased after cardiopulmonary bypass. CONCLUSIONS Cerebral oxygenation was maintained during regional cerebral perfusion at prebypass levels with deep hypothermia. However, after rewarming and separation from cardiopulmonary bypass, cerebral oxygenation was lower compared with prebypass or somatic values. These results indicate that cerebrovascular resistance is increased after deep hypothermic cardiopulmonary bypass, even with continuous perfusion techniques, placing the cerebral circulation at risk postoperatively.
Collapse
Affiliation(s)
- George M Hoffman
- Department of Pediatric Anesthesiology, Children's Hospital of Wisconsin and Medical College of Wisconsin, Milwaukee 53226, USA.
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Suehiro E, Ueda Y, Wei EP, Kontos HA, Povlishock JT. Posttraumatic hypothermia followed by slow rewarming protects the cerebral microcirculation. J Neurotrauma 2003; 20:381-90. [PMID: 12866817 DOI: 10.1089/089771503765172336] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In the clinical and laboratory setting, multiple reports have suggested the efficacy of hypothermia in blunting the damaging consequences of traumatic brain injury (TBI). With the use of posttraumatic hypothermia, it has been recognized that the time of initiation and duration of hypothermia are important variables in determining the degree of neuroprotection provided. Further, it has been recently recognized that the rate of posttraumatic rewarming is an important variable, with rapid rewarming exacerbating neuronal/axonal damage in contrast to slow rewarming which appears to provide enhanced neuroprotection. Although these findings have been confirmed in the brain parenchyma, no information exists for the cerebral microcirculation on the potential benefits of posttraumatic hypothermia followed by either slow or rapid rewarming. In the current communication we assess these issues in the pial circulation using a well-characterized model of TBI. Rats were prepared for the placement of cranial widows for direct assessment of the pial microcirculation prior to and after the induction of impact acceleration injury followed by moderate hypothermia with either subsequent slow or rapid rewarming strategies. The cranial windows allowed for the measurement of pial vessel diameter to assess ACh-dependent and CO2 reactivity in the chosen paradigms. ACh was applied topically to assess ACh-dependent dilation, while CO2 reactivity was assessed by changing the concentration of the inspired gas. Through this approach, it was found that posttraumatic hypothermia followed by slow rewarming maintained normal arteriolar vascular responses in terms of ACh-dependent dilation and CO2 reactivity. In contrast, arterioles subjected to TBI followed by normothermia or hypothermia and rapid rewarming showed impaired vasoreactivity in terms of their ACh-dependent and CO2 responses. This study provides additional evidence of the benefits of posttraumatic hypothermia followed by slow rewarming, demonstrating for the first time that the previously described neuroprotective effects extend to the cerebral microcirculation.
Collapse
Affiliation(s)
- Eiichi Suehiro
- Department of Anatomy and Neurobiology, Medical College of Virginia Campus of Virginia Commonwealth University, Richmond, Virginia 23298-0709, USA
| | | | | | | | | |
Collapse
|
19
|
Scumpia PO, Sarcia PJ, DeMarco VG, Stevens BR, Skimming JW. Hypothermia attenuates iNOS, CAT-1, CAT-2, and nitric oxide expression in lungs of endotoxemic rats. Am J Physiol Lung Cell Mol Physiol 2002; 283:L1231-8. [PMID: 12388361 DOI: 10.1152/ajplung.00102.2002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Endotoxemia stimulates endogenous nitric oxide formation, induces transcription of arginine transporters, and causes lung injury. Hypothermia inhibits nitric oxide formation and is used as a means of organ preservation. We hypothesized that hypothermia inhibits endotoxin-induced intrapulmonary nitric oxide formation and that this inhibition is associated with attenuated transcription of enzymes that regulate nitric oxide formation, such as inducible nitric oxide synthase (iNOS) and the cationic amino acid transporters 1 (CAT-1) and 2 (CAT-2). Rats were anesthetized and randomized to treatment with hypothermia (18-24 degrees C) or normothermia (36-38 degrees C). Endotoxin was administered intravascularly. Concentrations of iNOS, CAT-1, CAT-2 mRNA, iNOS protein, and nitrosylated proteins were measured in lung tissue homogenates. We found that hypothermia abrogated the endotoxin-induced increase in exhaled nitric oxide and lung tissue nitrotyrosine concentrations. Western blot analyses revealed that hypothermia inhibited iNOS, but not endothelial nitric oxide synthase, protein expression in lung tissues. CAT-1, CAT-2, and iNOS mRNA concentrations were lower in the lungs of hypothermic animals. These findings suggest that hypothermia protects against intrapulmonary nitric oxide overproduction and nitric oxide-mediated lung injury by inhibiting transcription of iNOS, CAT-1, and CAT-2.
Collapse
Affiliation(s)
- Philip O Scumpia
- Departments of Pediatrics and Physiology and Functional Genomics, University of Florida, Gainesville, Florida 32610, USA
| | | | | | | | | |
Collapse
|
20
|
Inoue S, Kawaguchi M, Kurehara K, Sakamoto T, Kitaguchi K, Furuya H. Effect of mild hypothermia on inodilator-induced vasodilation of pial arterioles in cats. THE JOURNAL OF TRAUMA 2002; 53:646-53. [PMID: 12394861 DOI: 10.1097/00005373-200210000-00005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Mild hypothermia has been proposed as a means of providing cerebral protection after traumatic brain injury. However, hypothermia has been shown to alter not only physiologic but also pharmacologic responses. The purpose of this study was to investigate whether mild hypothermia (3-4 degrees C temperature reduction) could alter cerebral vasodilation induced by inodilators, which are characterized by having an inotropic effect in addition to a vasodilatory effect. Isoproterenol (a beta-adrenergic receptor agonist), colforsin dapropate (an adenylate cyclase stimulant), and amrinone (a phosphodiesterase inhibitor) were chosen as inodilators. METHODS The cranial window technique, combined with microscopic video recording, was used. Forty-eight cats were randomly assigned to either a normothermic or a hypothermic group (33 degrees C). Isoproterenol, colforsin dapropate, or amrinone was topically applied in the cranial window and the diameter of pial arterioles was measured. RESULTS Topical administration of isoproterenol, colforsin dapropate, and amrinone produced a significant dilation in a dose-dependent manner during normothermia. The vasodilation induced by these inodilators was not affected by mild hypothermia. CONCLUSION The vasodilation induced by topical administration of isoproterenol, colforsin dapropate, and amrinone was not affected by mild hypothermia.
Collapse
Affiliation(s)
- Satoki Inoue
- Department of Anesthesiology, Nara Medical University, Kashihara, Japan
| | | | | | | | | | | |
Collapse
|
21
|
Ueno K, Takamoto S, Miyairi T, Morota T, Shibata K, Murakami A, Kotsuka Y. Cerebral metabolism of nitric oxide during retrograde cerebral perfusion. Asian Cardiovasc Thorac Ann 2002; 10:223-7. [PMID: 12213744 DOI: 10.1177/021849230201000307] [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: 11/15/2022]
Abstract
The aim of this study was to determine whether alpha- or pH-stat protects the brain during deep hypothermic retrograde cerebral perfusion. Fifteen anesthetized dogs on cardiopulmonary bypass were cooled to 18 degrees C under alpha-stat and underwent retrograde cerebral perfusion for 90 minutes under alpha-stat or pH-stat, or underwent antegrade cardiopulmonary bypass under alpha-stat as the control. Cerebral blood flow of the cortex was monitored and serial analyses of blood gases and total nitric oxide oxidation products made. Cerebral blood flow and cerebral metabolic rate for oxygen were significantly higher and plasma levels of nitric oxide oxidation products in the outflow from the brain were significantly lower in retrograde cerebral perfusion under pH-stat than under alpha-stat. This study shows that reduced levels of nitric oxide oxidation products may protect against neuronal damage induced by nitric oxide and that increased cerebral blood flow under pH-stat may lead to a reduction of nitric oxide oxidation products. Under retrograde cerebral perfusion, pH-stat is thus better than alpha-stat for protecting the brain.
Collapse
Affiliation(s)
- Katsuhito Ueno
- Department of Cardiothoracic Surgery Faculty of Medicine University of Tokyo Tokyo, Japan.
| | | | | | | | | | | | | |
Collapse
|
22
|
Inoue S, Kawaguchi M, Kurehara K, Sakamoto T, Kishi K, Einaga T, Kitaguchi K, Furuya H. Mild hypothermia can enhance pial arteriolar vasodilation induced by isoflurane and sevoflurane in cats. Crit Care Med 2002; 30:1863-9. [PMID: 12163807 DOI: 10.1097/00003246-200208000-00032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Volatile anesthetics have been shown to dilate cerebral vessels. Recent evidence suggests that mild hypothermia can alter vascular reactivity of the cerebral vessels. However, the effect of mild hypothermia on volatile anesthetic-induced vasodilation of cerebral vessels is unknown. In the present study, we investigated the effect of mild hypothermia on pial arteriolar vasodilation induced by isoflurane and sevoflurane in cats. DESIGN Prospective, randomized, experimental study with repeated measures. SETTING Investigational animal laboratory. SUBJECTS Forty cats were used for the study of systemic administration of volatile anesthetics, and 22 cats were used for the study of topical administration of volatile anesthetics. INTERVENTIONS This study was approved by the Animal Experiment Committee of Nara Medical University. Animals were anesthetized with pentobarbital to maintain suppressive electroencephalographic patterns, which were introduced to measure direct effects of anesthetic agents after removing metabolic effects. The cranial window technique, combined with microscopic video recording, was used for the measurement of small (50-100 microm) and large (100-200 microm) pial arteriolar diameter in an experiment. Animals were randomly assigned to either a normothermic (37 degrees C) or a hypothermic group (33 degrees C). Desired temperatures were maintained by using a water blanket. In the first phase of the study, the effect of hypothermia on pial arteriolar vasodilation induced by systemic administration of isoflurane or sevoflurane was assessed. Each cat received isoflurane or sevoflurane at 0.5, 1.0, 1.5, and 2.0 minimum alveolar anesthetic concentrations, and the diameter of pial arterioles was measured. In the second group of animals, the direct effect of isoflurane and sevoflurane on pial vessels was evaluated. The artificial cerebrospinal fluid bubbled with isoflurane or sevoflurane (minimum alveolar anesthetic concentrations of 1 or 3) was topically administered in the cranial window. MEASUREMENTS AND MAIN RESULTS Systemic and topical administration of isoflurane and sevoflurane produced significant dilation of both small and large pial arterioles in a dose-dependent manner during normothermia. In the hypothermic group, vasodilation of small pial arterioles by systemic administration of isoflurane and sevoflurane at a high concentration was significantly larger than in the normothermic group (p <.05). Vasodilation of both small and large pial arterioles by topical administration of isoflurane and sevoflurane was significantly greater in the hypothermic group than in the normothermic group (p <.05). CONCLUSIONS These results suggest that pial arteriolar vasodilation induced by isoflurane and sevoflurane can be enhanced by mild hypothermia in cats anesthetized with pentobarbital.
Collapse
Affiliation(s)
- Satoki Inoue
- Department of Anesthesiology, Nara Medical University, Nara, Japan
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Matthew CB, Sils IV, Bastille AM. Tissue-specific extravasation of albumin-bound Evans blue in hypothermic and rewarmed rats. Can J Physiol Pharmacol 2002; 80:233-43. [PMID: 11991235 DOI: 10.1139/y02-044] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The effects of hypothermia and rewarming on endothelial integrity were examined in intestines, kidney, heart, gastrocnemius muscle, liver, spleen, and brain by measuring albumin-bound Evans blue loss from the vasculature. Ten groups of twelve rats, normothermic with no pentobarbital, normothermic sampled at 2, 3, or 4 h after pentobarbital, hypothermic to 20, 25, or 30 degrees C, and rewarmed from 20, 25, or 30 degrees C, were cooled in copper coils through which water circulated. Hypothermic rats were cooled to the desired core temperature and maintained there for 1 h; rewarmed rats were cooled to the same core temperatures, maintained there for 1 h, and then rewarmed. Following Evans blue administration, animals were euthanized with methoxyflurane, tissues removed, and Evans blue extracted. Because hypothermia and rewarming significantly decrease blood flow, organ-specific flow rates for hypothermic and rewarmed tissues were used to predict extravasation. Hypothermia decreased extravasation in tissues with continuous endothelium (brain, muscle) and increased it in tissues with discontinuous endothelium (liver, lung, spleen). All tissues exhibited significant (p < 0.05) differences from normothermic controls. These differences are attributed to a combination of anesthesia, flow, and (or) change in endothelial permeability, suggesting that appropriate choice of organ and temperature would facilitate testing pharmacological means of promoting return to normal perfusion.
Collapse
Affiliation(s)
- Candace B Matthew
- U.S. Army Research Institute of Environmental Medicine (USARIEM), Natick, MA 01760-5007, USA.
| | | | | |
Collapse
|
24
|
Inoue S, Kawaguchi M, Kurehara K, Sakamoto T, Kitaguchi K, Furuya H. Effect of mild hypothermia on nicorandil-induced vasodilation of pial arterioles in cats. Crit Care Med 2001; 29:2162-8. [PMID: 11700414 DOI: 10.1097/00003246-200111000-00019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Nicorandil is characterized as hybrid between nitrates and potassium channel activators. Recent evidence suggested that mild hypothermia may alter cerebral vasodilation induced by a nitrate agent and potassium channel opener. However, the effect of mild hypothermia on nicorandil-induced vasodilation is not known. The present study was conducted to investigate whether mild hypothermia could alter nicorandil-induced cerebral vasodilation. In addition, the effects of mild hypothermia on cerebral vasodilation induced by nitroglycerin, a nitrate agent, and cromakalim, a selective adenosine 5'-triphosphate-sensitive potassium channel opener, were assessed in the same model. DESIGN Prospective, randomized, experimental study with repeated measures. SETTING Investigational animal laboratory. SUBJECTS Twenty-four cats. INTERVENTIONS Animals were anesthetized with pentobarbital. The cranial window technique, combined with microscopic video recording, was used to measure small (50-100 microm) and large (100-200 microm) pial arteriolar diameter in an experiment. Animals were assigned randomly to either a normothermic (37 degrees C) or a hypothermic (33 degrees C) group. Nicorandil, nitroglycerin, or cromakalim at concentrations of 10(-8), 10(-6), or 10(-4) mol/L was applied topically in the cranial window, and the diameter of pial arterioles was measured. MEASUREMENTS AND MAIN RESULTS Topical administration of nicorandil, nitroglycerin, and cromakalim significantly dilated both small and large pial arterioles in a dose-dependent manner during normothermia. Nicorandil-induced vasodilation of either large or small pial arterioles was not affected by hypothermia. However, hypothermia significantly attenuated nitroglycerine-induced vasodilation in both large and small pial arterioles and enhanced cromakalim-induced vasodilation in both large and small pial arterioles. CONCLUSIONS Nicorandil-induced vasodilation of cerebral pial arterioles was not affected by mild hypothermia. By contrast, mild hypothermia significantly attenuated nitroglycerin-induced vasodilation and enhanced cromakalim-induced vasodilation.
Collapse
Affiliation(s)
- S Inoue
- Department of Anesthesiology, Nara Medical University, Kashihara, Nara, Japan
| | | | | | | | | | | |
Collapse
|
25
|
Dahdah NS, Russo P, Wagerle LC. Phosphorylation in coronary artery cold-induced contraction in the newborn lamb. Cryobiology 2001; 42:40-8. [PMID: 11336488 DOI: 10.1006/cryo.2001.2299] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myocardial dysfunction after hypothermic protection has been linked to various mechanisms. Coronary vasospasm in particular may be responsible for ischemic injury during reperfusion. Herein we hypothesized that coronary arteries (CA) sustain a cold-induced contraction during hypothermia mediated by a protein tyrosine kinase (PTK)-/protein tyrosine phosphatase (PTP)-dependent pathway. Isolated newborn lamb CA rings were studied in a tissue bath for isometric contraction during 2-h profound (17 degrees C) or ultra-profound (7 degrees C) hypothermia. In parallel, protein tyrosine phosphorylation was evaluated by use of the Western blot technique. Na-orthovanadate (SOV) and genestein (GEN) were used separately and in combination to evaluate the effect of PTK/PTP activation on CA contraction and tyrosine phosphorylation during cooling (17 or 7 degrees C) vs 37 degrees C. Cooling from 37 to 7 degrees C induced transient contraction at approximately 17 degrees C (29% KCl response), which was more prominent during rewarming to 37 degrees C (36% KCl). Cooling to 17 degrees C resulted in sustained contraction (7-10% KCl), which was reversible upon rewarming. Cold-induced contraction was significantly enhanced by SOV (7- to 10-fold at 17 degrees C; 2-fold at 7 degrees C) and abolished by GEN. Concurrently, tyrosine phosphorylation of 33-, 45-, and 104-kDa proteins increased during cooling (35-100% at 17 degrees C; 46-66% at 7 degrees C). Tyrosine phosphorylation was similarly enhanced by SOV (1.7- to 2.3-fold at 17 degrees C; 2.9- to 3.9-fold at 7 degrees C) and abolished by GEN in the presence or absence of SOV. These results support a prominent role for the PTK/PTP signal transduction pathway in the coronary artery cold-induced contraction. This information provides one possible biomolecular mechanism linked to ischemia/reperfusion pathophysiology of CA in neonatal hearts exposed to hypothermic myocardial protection.
Collapse
Affiliation(s)
- N S Dahdah
- Department of Pediatrics, MetroHealth Medical Center, Cleveland, Ohio 44109, USA
| | | | | |
Collapse
|
26
|
Morelos M, Amyot R, Picano E, Rodriguez O, Mazzone AM, Glauber M, Biagini A. Effect of coronary bypass and cardiac valve surgery on systemic endothelial function. Am J Cardiol 2001; 87:364-6, A10. [PMID: 11165982 DOI: 10.1016/s0002-9149(00)01380-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Seventeen patients scheduled for a cardiac procedure necessitating cardiopulmonary bypass underwent serial perioperative assessment of brachial artery flow-mediated dilation. Patients who underwent coronary bypass surgery had a sustained systemic endothelial dysfunction in the perioperative period, whereas those undergoing cardiac valve surgery experienced transient postoperative systemic endothelial dysfunction.
Collapse
Affiliation(s)
- M Morelos
- CNR, Institute of Clinical Physiology, Pisa, Italy
| | | | | | | | | | | | | |
Collapse
|
27
|
Ingyinn M, Lee J, Short BL, Viswanathan M. Venoarterial extracorporeal membrane oxygenation impairs basal nitric oxide production in cerebral arteries of newborn lambs. Pediatr Crit Care Med 2000; 1:161-5. [PMID: 12813269 DOI: 10.1097/00130478-200010000-00013] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Based on previous studies in our laboratory showing that exposure of newborn lambs to venoarterial extracorporeal membrane oxygenation (ECMO) alters cerebral blood flow autoregulation, we postulated that this altered vascular reactivity is mediated through changes in endothelial function caused by the pumping systems used in venoarterial ECMO. We tested that hypothesis in this study. DESIGN Prospective, controlled, laboratory trial. SETTING Animal research laboratory. SUBJECTS Two groups of newborn lambs. INTERVENTIONS One group of animals was exposed to venoarterial ECMO (n = 6) and another group of control animals (n = 5) was maintained under similar conditions for 2 hrs on the ventilator without ECMO. MEASUREMENTS AND MAIN RESULTS Third-order branches of the middle cerebral arteries (140-300 microm diameter) were isolated from animals at the end of the experiment, mounted on glass cannulae in an arteriograph, and superfused with Krebs-Ringer buffer. Decrease in the diameter of the arteries induced by exposure of the vessels to nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (200 micromol/L) for 30 mins was significantly less (p <.05) in arteries from lambs exposed to ECMO compared with control animals. There were no significant differences between the two groups in myogenic response or in the contractile activity of the arteries to increasing concentrations of serotonin. CONCLUSIONS These results demonstrate that 2 hrs of exposure of newborn lambs to venoarterial ECMO leads to a decrease in basal production of nitric oxide in cerebral arteries, and suggest that venoarterial ECMO selectively impairs cerebral arterial endothelial function.
Collapse
Affiliation(s)
- M Ingyinn
- Department of Neonatology, Children's Research Institute, Washington, DC 20010-2970, USA
| | | | | | | |
Collapse
|
28
|
Cooper WA, Duarte IG, Thourani VH, Nakamura M, Wang NP, Brown WM, Gott JP, Vinten-Johansen J, Guyton RA. Hypothermic circulatory arrest causes multisystem vascular endothelial dysfunction and apoptosis. Ann Thorac Surg 2000; 69:696-702; discussion 703. [PMID: 10750746 DOI: 10.1016/s0003-4975(99)01524-6] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Multiple organ failure after deep hypothermic circulatory arrest (DHCA) may occur secondary to endothelial dysfunction and apoptosis. We sought to determine if DHCA causes endothelial dysfunction and apoptosis in brain, kidney, lungs, and other tissues. METHODS Anesthetized pigs on cardiopulmonary bypass were: (1) cooled to 18 degrees C, and had their circulation arrested (60 minutes) and reperfused at 37 degrees C for 90 minutes (DHCA, n = 8); or (2) time-matched normothermic controls on bypass (CPB, n = 6). Endothelial function in cerebral, pulmonary, and renal vessels was assessed by vasorelaxation responses to endothelial-specific bradykinin (BK) or acetylcholine (ACh), and smooth muscle-specific nitroprusside. RESULTS In vivo transcranial vasorelaxation responses to ACh were similar between the two groups. In small-caliber cerebral arteries, endothelial relaxation (BK) was impaired in CPB vs DHCA (maximal 55% +/- 2% [p < 0.05] vs 100% +/- 6%). Pulmonary artery ACh responses were comparable between CPB (110% +/- 10%) and DHCA (83% +/- 6%), but responses in pulmonary vein were impaired in DHCA (109% +/- 3%, p < 0.05) relative to CPB (137% +/- 6%). In renal arteries, endothelial (ACh) responses were impaired in DHCA (71% +/- 13%) relative to CPB (129% +/- 14%). Apoptosis (DNA laddering) occurred primarily in duodenal tissue, with a greater frequency in DHCA (56%, p < 0.05) compared with normothermic CPB (17%) and nonbypass controls (0%). CONCLUSIONS DHCA is associated with endothelial dysfunction in cerebral microvessels but not in the in vivo transcranial vasculature; in addition, endothelial dysfunction was noted in large-caliber renal arteries and pulmonary veins. DHCA is also associated with duodenal apoptosis. Vascular endothelial dysfunction and apoptosis may be involved in the pathophysiology of multisystem organ failure after DHCA.
Collapse
Affiliation(s)
- W A Cooper
- Cardiothoracic Research Laboratory, Carlyle Fraser Heart Center of Crawford Long Hospital, and Emory University School of Medicine, Atlanta, Georgia 30365, USA
| | | | | | | | | | | | | | | | | |
Collapse
|