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Lautz L, Dorne J, Oldenkamp R, Hendriks A, Ragas A. Generic physiologically based kinetic modelling for farm animals: Part I. Data collection of physiological parameters in swine, cattle and sheep. Toxicol Lett 2020; 319:95-101. [DOI: 10.1016/j.toxlet.2019.10.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/09/2019] [Accepted: 10/22/2019] [Indexed: 11/30/2022]
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King MR, Anderson TA, Sui J, He G, Poon KYT, Coté CJ. Age-related incidence of desaturation events and the cardiac responses on stroke index, cardiac index, and heart rate measured by continuous bioimpedance noninvasive cardiac output monitoring in infants and children undergoing general anesthesia. J Clin Anesth 2016; 32:181-8. [PMID: 27290971 DOI: 10.1016/j.jclinane.2016.02.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 02/12/2016] [Accepted: 02/18/2016] [Indexed: 12/31/2022]
Abstract
STUDY OBJECTIVE To assess the effects of desaturation on stroke index (SI), cardiac index (CI), and heart rate (HR) using the ICON continuous noninvasive cardiac output monitor in children undergoing general anesthesia. DESIGN Retrospective analysis of a prospectively collected data set. SETTING Pediatric operating rooms in a tertiary academic medical center. PATIENTS Children younger than 20 years who experienced desaturation while undergoing general anesthesia. INTERVENTION All records were retrospectively searched for desaturation events defined as a recorded Spo2 ≤ 90%. We compared the data from the prior 4 minutes (baseline) with mild, moderate, and severe levels of desaturation. MEASUREMENTS The relationship between Spo2 and percent change in SI, CI, and HR from baseline was assessed using a generalized linear model with repeated measures and the least-squares method. MAIN RESULTS Data from 446 patients were reviewed; 38 events were eligible for analysis after exclusions. There were significant decreases in SI at all saturation ranges below 95%: -6.5% (P < .001) for 85%-95%, -8.9% (P = .002) for 71%-84%, and -11% (P < .001) for ≤70%. Based on the result from the regression, Spo2 was associated with change in SI with borderline significance (P = .053) but not that of HR and CI. There was a strong relationship to desaturation events with young age (P < .001), particularly infants younger than 6 months. CONCLUSION Events associated with desaturation in children under general anesthesia were significantly associated with decreased SI with a greater effect with lower saturation nadirs. It is unclear if other concurrent events could have also contributed to adverse hemodynamic responses during desaturation. In most children, a compensatory increase in HR generally offsets concurrent decreases in CI. It would appear that bradycardia is a late manifestation of hypoxemia.
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Affiliation(s)
- Michael R King
- Department of Anesthesiology and Critical Care, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
| | - T Anthony Anderson
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Jinghu Sui
- Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Guoluo He
- Department of Anesthesia, Jiangxi Province General Hospital, Nanchang, China
| | - Kwun Yee T Poon
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Charles J Coté
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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Abstract
The neonatal gastrointestinal tract is a site of intense anabolic and metabolic activity, as it is responsible for the assimilation of nutritional intake and exhibits accelerated growth shortly after birth. The hypermetabolic state of the gastrointestinal tract requires sufficient blood flow and oxygen delivery to sustain adequate oxygen consumption to meet these metabolic needs. Therefore, an understanding of the mechanisms regulating intestinal vascular perfusion in the normal state and during pathophysiological conditions in the perinatal period is important to elucidate potential contributions to the development of intestinal pathologies in the neonate. The goal of this review is to summarize the available literature on the regulation of intestinal blood flow and oxygenation in the fetus and newborn in normal states and during pathological stress.
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Affiliation(s)
- Hala Chaaban
- Department of Pediatrics, Oklahoma University Health Sciences Center, Oklahoma City, OK, USA
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Effect of Body Positions on Hemodynamics and Gas Exchange in Anesthetized Pigs Shortly After Pneumonectomy. Shock 2010; 34:482-7. [DOI: 10.1097/shk.0b013e3181dc0812] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Effects of Spontaneous Breathing During Airway Pressure Release Ventilation on Cerebral and Spinal Cord Perfusion in Experimental Acute Lung Injury. J Neurosurg Anesthesiol 2010; 22:323-9. [DOI: 10.1097/ana.0b013e3181e775f1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Stevens JP, Churchill T, Fokkelman K, Haase E, Idikio H, Korbutt G, Bigam DL, Cheung PY. Oxidative stress and matrix metalloproteinase-9 activity in the liver after hypoxia and reoxygenation with 21% or 100% oxygen in newborn piglets. Eur J Pharmacol 2007; 580:385-93. [PMID: 18154950 DOI: 10.1016/j.ejphar.2007.11.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Revised: 08/08/2007] [Accepted: 11/15/2007] [Indexed: 11/26/2022]
Abstract
We designed a randomized controlled study to identify and compare the liver tissue responses in systemic hypoxia and resuscitation with 21% and 100% oxygen using an animal model of neonatal hypoxia and reoxygenation. Twenty-seven piglets (1-3 days old, weight 1.5-2.0 kg) were acutely instrumented and mechanically ventilated. The animals underwent 2 h of normocapnic alveolar hypoxia (10-15% oxygen) then reoxygenation with 21% or 100% oxygen for 1 h, then 1 h with 21% oxygen. Controls were sham-operated without hypoxia-reoxygenation. After 2 h of reoxygenation liver tissue samples were immediately processed for histological and biochemical analyses of markers of oxidative stress and tissue injury. Two hours of hypoxia caused a significant reduction in mean arterial pressure with cardiogenic shock and metabolic acidemia, with similar recovery upon resuscitation with 21% and 100% oxygen. After 2 h of reoxygenation, the hepatic GSSG:total glutathione ratio and matrix metalloproteninase-9 activity, which correlated with the portal venous oxygenation at 15 min of reoxygenation, were greater in the 100% group and hepatic lactate level was higher in the 21% group than the controls (all P<0.05). Both hypoxic-reoxygenated groups had similarly elevated hepatic Bcl-2 levels. Apart from more non-distinct mitochondria identified in the 100% group, hepatic tissue adenylate energy charge and plasma transaminases levels did not differ among groups. We concluded that in this acute model of neonatal hypoxia and reoxygenation, resuscitation using 21% oxygen avoids the excess oxidative stress and elevated matrix metalloproteninase-9 activity in the liver when 100% oxygen was used. The study supports the conservative use of oxygen in optimizing post-hypoxic hepatic recovery.
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Stevens JP, Haase E, Churchill T, Bigam DL, Cheung PY. RESUSCITATION WITH 21% OR 100% OXYGEN IS EQUALLY EFFECTIVE IN RESTORING PERFUSION AND OXYGEN METABOLISM IN THE LIVER OF HYPOXIC NEWBORN PIGLETS. Shock 2007; 27:657-62. [PMID: 17505306 DOI: 10.1097/shk.0b013e31802b63a4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The differential effects of the use of high or low oxygen levels during resuscitation on the neonatal liver are unknown. We compared the hepatic hemodynamics and oxygen metabolism in hypoxic newborn piglets resuscitated with 21% or 100% oxygen. Twenty-seven piglets (age, 1-3 days; weight, 1.5-2.0 kg) were acutely instrumented to measure cardiac output, hepatic artery, and portal venous blood flows (hepatic artery flow index [HAFI] and portal venous flow index [PVFI], respectively). The animals underwent 2 h of hypoxia (fraction of inspired oxygen, 0.10-0.15), then reoxygenation with 21% (n = 9) or 100% (n = 9) oxygen for 1 h, then 1 h with 21% oxygen. The controls (n = 9) were sham-operated without hypoxia-reoxygenation. Oxygen transport and plasma lactate concentrations were studied. Hypoxic animals had hypotension and decreased cardiac index with metabolic acidosis (mean pH, 7.00-7.02; P < 0.05 vs. controls). The PVFI and the total hepatic blood flow (THFI = PVFI + HAFI), despite the absence of significant change in HAFI, decreased to 16 +/- 2 mL/min/kg and 19 +/- 3 mL/min/kg, respectively (versus 24 +/- 2 mL/min/kg and 28 +/- 2 mL/min/kg of controls; P < 0.05). Fifteen minutes after reoxygenation, the cardiac index improved, PVFI recovered, HAFI was maintained, and THFI was not different between the groups. The hepatic oxygen consumption decreased (59%; P < 0.05) and the extraction increased (89%; P < 0.001) during hypoxia. Similarly, on reoxygenation, the hepatic oxygen consumption improved; however, extraction decreased versus controls on 100% but not on 21% oxygen (P < 0.05). The plasma lactate concentrations increased in both groups with hypoxia and were not different during reoxygenation between the group administered with 21% oxygen and the group administered with 100% oxygen. The hypoxic neonatal liver has reduced hepatic blood flow but has relatively preserved HAFI, and oxygen consumption recovered similarly on reoxygenation with 21% and 100% oxygen. The increased oxygen extraction during hypoxia normalized in 21% but reduced in 100% reoxygenation, with no differences in plasma lactate concentrations.
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Affiliation(s)
- Jonathan P Stevens
- Departments of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
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Ricci M, Lombardi P, Galindo A, Vasquez A, Zuccarelli J, Rosenkranz E. Distribution of cardiac output and oxygen delivery in an acute animal model of single-ventricle physiology. J Thorac Cardiovasc Surg 2005; 130:1062-70. [PMID: 16214521 DOI: 10.1016/j.jtcvs.2005.05.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2005] [Revised: 04/11/2005] [Accepted: 05/19/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND When single-ventricle physiology is established acutely (ie, after a Norwood procedure), the combination of limited cardiac output and hypoxemia could result in limited oxygen transport to systemic organs. This study investigates the regional distribution of cardiac output and oxygen delivery after creation of single-ventricle physiology. METHODS Single-ventricle physiology was created in 8 piglets, and 8 other piglets served as sham control animals. Aortopulmonary shunt, echocardiography-guided atrial septostomy, tricuspid valve avulsion, and pulmonary artery occlusion allowed the left ventricle to support systemic and pulmonary circulations. Physiologic parameters and regional blood flow were determined at baseline and at 30 and 120 minutes after conversion to single-ventricle physiology. Parameters were compared by means of 1-way and 2-way analysis of variance. RESULTS Single-ventricle physiology resulted in lower diastolic arterial pressure, oxygen saturation, and arterial oxygen saturation (P < .05), whereas hemoglobin was unchanged. Cerebral blood flow increased markedly in control animals (P = .04). In contrast, in single-ventricle physiology regional blood flow was unchanged in the brain, higher in the myocardium (P = .1), and mildly reduced in low-priority organs (liver, kidneys, and bowel). Cerebral oxygen delivery increased in control animals, whereas in animals with single-ventricle physiology, oxygen delivery decreased in the brain, liver, kidneys, and bowel (P < .05) and was unchanged in the myocardium. Total-body oxygen delivery decreased in animals with single-ventricle physiology (P < .001) but not in control animals. Total-body oxygen consumption was unchanged in both groups. CONCLUSIONS This study shows that in acute single-ventricle physiology hypoxemia and limited regional blood flow reduce oxygen transport to low-priority organs and partly to the brain. These findings might contribute to the understanding of gastrointestinal and neurologic complications in children with single-ventricle physiology.
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Affiliation(s)
- Marco Ricci
- Holtz Children's Hospital, University of Miami Miller School of Medicine, Miami, Fla 33136, USA.
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Ricci M, Lombardi P, Galindo A, Coscarella E, Vasquez A, Rosenkranz E. Single-Ventricle Physiology Reduces Cerebral Oxygen Delivery in a Piglet Model. Ann Thorac Surg 2005; 80:686-93; discussion 694. [PMID: 16039229 DOI: 10.1016/j.athoracsur.2005.03.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Revised: 02/28/2005] [Accepted: 03/04/2005] [Indexed: 11/23/2022]
Abstract
BACKGROUND In single-ventricle physiology, cerebral blood flow and oxygen (O2) delivery may be inadequate. This study tests the hypotheses that in acute univentricular physiology (1) cerebral blood flow increases inadequately to maintain O2 delivery, (2) the brain is incapable of increasing O2 extraction due to hypoxemia, and (3) cerebral O2 delivery diminishes selectively in different brain regions. MATERIAL AND METHODS Univentricular physiology was created in 8 piglets, while 8 animals were sham controls. Aortopulmonary shunt, echocardiography-guided atrial septostomy, tricuspid valve avulsion, and pulmonary artery occlusion were performed to allow the left ventricle to support systemic and pulmonary circulations. Cerebral blood flow (microspheres), cerebral O2 and lactate metabolism, and cerebral O2 saturation were measured at baseline, 30 minutes, and 120 minutes after conversion to univentricular physiology. RESULTS Cerebral blood flow increased in the cerebrum and subtentorium in controls (p < 0.05), whereas it remained unchanged in univentricular piglets. Cerebral O2 delivery at 30 and 120 minutes was lower in univentricular physiology than in controls (p = 0.05). Fractional oxygen extraction was unchanged in both groups. Cerebral O2 consumption trended lower in univentricular physiology (p = not significant), while it was unchanged in controls. Lactate cerebral metabolic rate (CMRLactate) increased at 30 and 120 minutes in both groups. The decline in O2 delivery was variable, but present in nearly all brain regions. CONCLUSIONS This study confirms the hypothesis that, in univentricular physiology, hypoxemia and limited cerebral blood flow reduce cerebral O2 availability in nearly all regions. These findings contribute to the understanding of brain abnormalities in infants with univentricular physiology.
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Affiliation(s)
- Marco Ricci
- Division of Cardiothoracic Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA.
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Hoffman GM, Ghanayem NS, Kampine JM, Berger S, Mussatto KA, Litwin SB, Tweddell JS. Venous saturation and the anaerobic threshold in neonates after the Norwood procedure for hypoplastic left heart syndrome. Ann Thorac Surg 2000; 70:1515-20; discussion 1521. [PMID: 11093480 DOI: 10.1016/s0003-4975(00)01772-0] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND Reduction in oxygen delivery can lead to organ dysfunction and death by cellular hypoxia, detectable by progressive (mixed) venous oxyhemoglobin desaturation until extraction is limited at the anaerobic threshold. We sought to determine the critical level of venous oxygen saturation to maintain aerobic metabolism in neonates after the Norwood procedure (NP) for the hypoplastic left heart syndrome (HLHS). METHODS A prospective perioperative database was maintained for demographic, hemodynamic, and laboratory data. Invasive arterial and atrial pressures, arterial saturation, oximetric superior vena cava (SVC) saturation, and end-tidal CO2 were continuously recorded and logged hourly for the first 48 postoperative hours. Arterial and venous blood gases and cooximetry were obtained at clinically appropriate intervals. SVC saturation was used as an approximation of mixed venous saturation (SvO2). A standard base excess (BE) less than -4 mEq/L (BElo), or a change exceeding -2 mEq/L/h (deltaBElo), were used as indicators of anaerobic metabolism. The relationship between SvO2 and BE was tested by analysis of variance and covariance for repeated measures; the binomial risk of BElo or deltaBElo at SvO2 strata was tested by the likelihood ratio test and logistic regression, with cutoff at p < 0.05. RESULTS Complete data were available in 48 of 51 consecutive patients undergoing NP yielding 2,074 valid separate determinations. BE was strongly related to SvO2 (model R2 = 0.40, p < 0.0001) with minimal change after adjustment for physiologic covariates. The risk of anaerobic metabolism was 4.8% overall, but rose to 29% when SvO2 was 30% or below (p < 0.0001). Survival was 100% at 1 week and 94% at hospital discharge. CONCLUSIONS Analysis of acid-base changes revealed an apparent anaerobic threshold when SvO2 fell below 30%. Clinical management to maintain SvO2 above this threshold yielded low mortality.
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Affiliation(s)
- G M Hoffman
- Department of Anesthesiology, Children's Hospital of Wisconsin and Medical College of Wisconsin, Milwaukee 53226, USA.
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Goldstein M, Rehan VK, Oh W, Stonestreet BS. Cerebral and intestinal perfusion and metabolism in normocythemic hyperviscous hypoxic newborn pigs. J Appl Physiol (1985) 2000; 88:2107-15. [PMID: 10846024 DOI: 10.1152/jappl.2000.88.6.2107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We studied the effects of hypoxia on cerebral cortical and intestinal perfusion and metabolism in normocythemic hyperviscous newborn pigs. Seven pigs were made hyperviscous by an injection of cryoprecipitate, increasing viscosity from 5.8 +/- 0.9 to 9.0 +/- 1. 2 (SD) cycles/s. Six normoviscous pigs received 0.9% NaCl. Reducing the inspired O(2) decreased the arterial O(2) content (Ca(O(2))) from 9.5 +/- 1.6 to 3.6 +/- 1.3 ml O(2)/100 ml. Increases in brain and decreases in gastrointestinal blood flow at the lower Ca(O(2)) values were similar between the groups. During hypoxia, blood flow to stomach, distal intestinal mucosa, and large intestines was lower (-50, -23, and -28%, respectively) in the hyperviscous than normoviscous group. At the lower Ca(O(2)) values, cerebral cortical vascular resistance decreased in both groups and intestinal vascular resistance increased (+257%) in the hyperviscous but not in the normoviscous group. During hypoxia, systemic oxygen delivery decreased, extraction increased, and uptake did not change; cerebral cortical O(2) delivery, extraction, and uptake did not change; and intestinal O(2) delivery decreased, extraction increased, and uptake did not change in both groups. Our study demonstrated that 1) during hypoxia, increases in systemic O(2) extraction compensated for decreases in delivery and systemic uptake did not change; vasodilation sustained cerebral cortical O(2) delivery and preserved metabolism; increases in intestinal oxygen extraction offset decreases in delivery and uptake was preserved; and 2) nonpolycythemic hyperviscosity did not have a major influence on cardiovascular or metabolic responses to hypoxia, except for modest effects on intestinal resistance and perfusion to certain gastrointestinal regions. We conclude that, under normocythemic conditions, a moderate increase in viscosity does not have a major impact on hemodynamic or metabolic adjustments to hypoxia in newborn pigs.
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Affiliation(s)
- M Goldstein
- Department of Pediatrics, Women and Infants' Hospital of Rhode Island, Brown University School of Medicine, Providence 02905, USA
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