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Morgan CG, Neidert LE, Hathaway EN, Rodriguez GJ, Schaub LJ, Cardin S, Glaser JJ. Evaluation of prolonged 'Permissive Hypotension': results from a 6-hour hemorrhage protocol in swine. Trauma Surg Acute Care Open 2019; 4:e000369. [PMID: 31803845 PMCID: PMC6887504 DOI: 10.1136/tsaco-2019-000369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/11/2019] [Accepted: 10/25/2019] [Indexed: 11/17/2022] Open
Abstract
Background Tactical Combat Casualty Care guidelines for hemorrhage recommend resuscitation to systolic blood pressure (SBP) of 85±5 mm Hg during prehospital care. Success depends on transport to definitive care within the ‘golden hour’. As future conflicts may demand longer prehospital/transport times, we sought to determine safety of prolonged permissive hypotension (PH). Methods Adult male swine were randomized into three experimental groups. Non-shock (NS)/normotensive underwent anesthesia only. NS/PH was bled to SBP of 85±5 mm Hg for 6 hours of prolonged field care (PFC) with SBP maintained via crystalloid, then recovered. Experimental group underwent controlled hemorrhage to mean arterial pressure 30 mm Hg until decompensation (Decomp/PH), followed by 6 hours of PFC. Hemorrhaged animals were then resuscitated with whole blood and observed for 24 hours. Physiologic variables, blood, tissue samples, and neurologic scores were collected. Results Survival of all groups was 100%. Fluid volumes to maintain targeted SBP in PFC were significantly higher in the hemorrhage group than sham groups. After 24 hours’ recovery, no significant differences were observed in neurologic scores or cerebrospinal fluid markers of brain injury. No significant changes in organ function related to treatment were observed during PFC through recovery, as assessed by serum chemistry and histological analysis. Conclusions After 6 hours, a prolonged PH strategy showed no detrimental effect on survival or neurologic outcome despite the increased ischemic burden of hemorrhage. Significant fluid volume was required to maintain SBP—a potential logistic burden for prehospital care. Further work to define maximum allowable time of PH is needed. Study type Translational animal model. Level of evidence N/A.
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Affiliation(s)
- Clifford G Morgan
- Expeditionary and Trauma Medicine, Naval Medical Research Unit San Antonio, Fort Sam Houston, San Antonio, Texas, USA
| | - Leslie E Neidert
- Expeditionary and Trauma Medicine, Naval Medical Research Unit San Antonio, Fort Sam Houston, San Antonio, Texas, USA
| | - Emily N Hathaway
- Division of Trauma Critical Care, San Antonio Military Medical Center, San Antonio, Texas, USA
| | - Gerardo J Rodriguez
- Expeditionary and Trauma Medicine, Naval Medical Research Unit San Antonio, Fort Sam Houston, San Antonio, Texas, USA
| | - Leasha J Schaub
- Expeditionary and Trauma Medicine, Naval Medical Research Unit San Antonio, Fort Sam Houston, San Antonio, Texas, USA
| | - Sylvain Cardin
- Expeditionary and Trauma Medicine, Naval Medical Research Unit San Antonio, Fort Sam Houston, San Antonio, Texas, USA
| | - Jacob J Glaser
- Expeditionary and Trauma Medicine, Naval Medical Research Unit San Antonio, Fort Sam Houston, San Antonio, Texas, USA.,Division of Trauma Critical Care, San Antonio Military Medical Center, San Antonio, Texas, USA
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Ren L, Yu K, Tan Y. Monitoring and Assessing the Degradation Rate of Magnesium-Based Artificial Bone In Vitro Using a Wireless Magnetoelastic Sensor. SENSORS 2018; 18:s18093066. [PMID: 30213118 PMCID: PMC6165446 DOI: 10.3390/s18093066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 08/29/2018] [Accepted: 09/10/2018] [Indexed: 11/24/2022]
Abstract
A magnetoelastic-based (MB) sensor was employed as a novel method to monitor and assess the degradation rate of magnesium-based artificial bone (MBAB) in vitro, which can be used as an implant to repair a bone defect, providing a quantitative method to depict the degradation rate of MBAB. MBABs were fabricated by the Pro/Engineering software and a precision machine tool using high-purity (HP) magnesium. The MB sensor was embedded in the neutral surface of MBAB by an unharmful quick adhesive, forming the MB sensor-embedded MBAB (EMBAB). The modified simulated body fluid (MSBF) media (PH = 7.4), mimicking the human internal environment, and the NaOH media (PH = 12), accelerating EMBAB’s degradation, were used to immerse the EMBAB for 15 days at 37 °C. The EMBAB was then tested daily on a self-developed experimental platform to monitor the relative output power under a 100 N external force. The results showed that the relative output power of the sensing coil gradually increased with the EMBAB’s degradation. The degradation rate of the EMBAB could be calculated on the basis of the changes of the relative output power caused by the MB sensor and of the degradation time. With the EMBAB’s degradation, an increasing strain directly worked on the MB sensor, significantly changing the value of the relative output power, which means that the EMBAB was characterized by a quick degradation rate. During the 15 days of the experiment, the degradation rates on the 7th and 15th days were 0.005 dbm/day and 0.02 dbm/day, and 0.02 dbm/day and 0.04 dbm/day in MSBF and alkaline media, respectively. Therefore, the MB sensor provides a wireless and passive method to monitor and assess the degradation rate of bone implants in vitro.
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Affiliation(s)
- Limin Ren
- School of Mechanical Engineering, Northeast Electric Power University, Jilin 132012, China.
| | - Kun Yu
- School of Mechanical Engineering, Northeast Electric Power University, Jilin 132012, China.
| | - Yisong Tan
- School of Mechanical Engineering, Northeast Electric Power University, Jilin 132012, China.
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Kord Forooshani P, Lee BP. Recent approaches in designing bioadhesive materials inspired by mussel adhesive protein. JOURNAL OF POLYMER SCIENCE. PART A, POLYMER CHEMISTRY 2017; 55:9-33. [PMID: 27917020 PMCID: PMC5132118 DOI: 10.1002/pola.28368] [Citation(s) in RCA: 349] [Impact Index Per Article: 49.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 09/03/2016] [Indexed: 12/11/2022]
Abstract
Marine mussels secret protein-based adhesives, which enable them to anchor to various surfaces in a saline, intertidal zone. Mussel foot proteins (Mfps) contain a large abundance of a unique, catecholic amino acid, Dopa, in their protein sequences. Catechol offers robust and durable adhesion to various substrate surfaces and contributes to the curing of the adhesive plaques. In this article, we review the unique features and the key functionalities of Mfps, catechol chemistry, and strategies for preparing catechol-functionalized polymers. Specifically, we reviewed recent findings on the contributions of various features of Mfps on interfacial binding, which include coacervate formation, surface drying properties, control of the oxidation state of catechol, among other features. We also summarized recent developments in designing advanced biomimetic materials including coacervate-forming adhesives, mechanically improved nano- and micro-composite adhesive hydrogels, as well as smart and self-healing materials. Finally, we review the applications of catechol-functionalized materials for the use as biomedical adhesives, therapeutic applications, and antifouling coatings. © 2016 The Authors. Journal of Polymer Science Part A: Polymer Chemistry Published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 9-33.
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Affiliation(s)
- Pegah Kord Forooshani
- Department of Biomedical EngineeringMichigan Technological UniversityHoughtonMichigan49931
| | - Bruce P. Lee
- Department of Biomedical EngineeringMichigan Technological UniversityHoughtonMichigan49931
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Comparison of Noninvasive pH and Blood Lactate as Predictors of Mortality in a Swine Hemorrhagic Shock with Restricted Volume Resuscitation Model. Shock 2016; 44 Suppl 1:90-5. [PMID: 25526374 PMCID: PMC4498648 DOI: 10.1097/shk.0000000000000307] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Recent clinical studies have demonstrated that high blood lactate in the prehospital setting and poor lactate clearance in the emergency department are predictive of in-hospital mortality. This analysis of data collected from a swine model of hemorrhage and restricted volume resuscitation investigated the hypotheses that noninvasive muscle pH (pHm) and H+ clearance would predict mortality, and the responses would be similar between pHm and lactate. Data from a set of 57 swine were analyzed over the first 2 h after controlled hemorrhage and uncontrolled splenic bleeding. Surviving animals were ones that lived for the full 5-h experimental period. Venous lactate was determined at baseline, shock, and at 30, 60, and 120 min after injury. Spectra were collected continuously from the posterior thigh using a prototype CareGuide 1100 Oximeter and pHm calculated from the spectra; H+ concentration was determined from pHm. Lactate clearance rate was calculated from the difference in lactate concentration at 120 min and shock, and H+ clearance was calculated in a similar manner. Comparison of the area under the receiver operator characteristic curves was used to assess prediction of survival at 5 h after injury. At 120 min after injury, lactate, lactate clearance, noninvasive pHm, and noninvasive H+ clearance were equivalent predictors of mortality each with a receiver operator characteristic area under the curve of 0.87. Thresholds for single lactate (<3.8 mmol/L) or pHm (>7.30) determinations were found to be consistent with a resuscitation goal targeted to reverse acidosis. Continuous, noninvasive pHm monitoring may provide a substitute for lactate measurement in trauma patients, particularly in the prehospital and emergency department settings.
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Lin MH, Anderson J, Pinnaratip R, Meng H, Konst S, DeRouin AJ, Rajachar R, Ong KG, Lee BP. Monitoring the Long-Term Degradation Behavior of Biomimetic Bioadhesive Using Wireless Magnetoelastic Sensor. IEEE Trans Biomed Eng 2016; 62:1838-42. [PMID: 26087077 DOI: 10.1109/tbme.2015.2405251] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The degradation behavior of a tissue adhesive is critical to its ability to repair a wound while minimizing prolonged inflammatory response. Traditional degradation tests can be expensive to perform, as they require large numbers of samples. The potential for using magnetoelastic resonant sensors to track bioadhesive degradation behavior was investigated. Specifically, biomimetic poly (ethylene glycol)- (PEG-) based adhesive was coated onto magnetoelastic (ME) sensor strips. Adhesive-coated samples were submerged in solutions buffered at multiple pH levels (5.7, 7.4 and 10.0) at body temperature (37 °C) and the degradation behavior of the adhesive was tracked wirelessly by monitoring the changes in the resonant amplitude of the sensors for over 80 days. Adhesive incubated at pH 7.4 degraded over 75 days, which matched previously published data for bulk degradation behavior of the adhesive while utilizing significantly less material (∼10(3) times lower). Adhesive incubated at pH 10.0 degraded within 25 days while samples incubated at pH 5.7 did not completely degrade even after 80 days of incubation. As expected, the rate of degradation increased with increasing pH as the rate of ester bond hydrolysis is higher under basic conditions. As a result of requiring a significantly lower amount of samples compared to traditional methods, the ME sensing technology is highly attractive for fully characterizing the degradation behavior of tissue adhesives in a wide range of physiological conditions.
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Cencer M, Murley M, Liu Y, Lee BP. Effect of Nitro-Functionalization on the Cross-Linking and Bioadhesion of Biomimetic Adhesive Moiety. Biomacromolecules 2014; 16:404-10. [PMID: 25495043 PMCID: PMC4294588 DOI: 10.1021/bm5016333] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
![]()
Dopamine
mimics the exceptional moisture-resistant adhesive properties
of the amino acid, DOPA, found in adhesive proteins secreted by marine
mussels. The catechol side chain of dopamine was functionalized with
a nitro-group, and the effect of the electron withdrawing group modification
on the cross-linking chemistry and bioadhesive properties of the adhesive
moiety was evaluated. Both nitrodopamine and dopamine were covalently
attached as a terminal group onto an inert, 4-armed poly(ethylene
glygol) (PEG-ND and PEG-D, respectively). PEG-ND and PEG-D exhibited
different dependence on the concentration of NaIO4 and
pH, which affected the curing rate, mechanical properties, and adhesive
performance of these biomimetic adhesives differently. PEG-ND cured
instantly and its bioadhesive properties were minimally affected by
the change in pH (5.7–8) within the physiological range. Under
mildly acidic conditions (pH 5.7 and 6.7), PEG-ND outperformed PEG-D
in lap shear adhesion testing using wetted pericardium tissues. However,
nitrodopamine only formed dimers, which resulted in the formation
of loosely cross-linked network and adhesive with reduced cohesive
properties. UV–vis spectroscopy further confirmed nitrodopamine’s
ability for rapid dimer formation. The ability for nitrodopamine to
rapidly cure and adhere to biological substrates in an acidic pH make
it suitable for designing adhesive biomaterials targeted at tissues
that are more acidic (i.e., subcutaneous, dysoxic, or tumor tissues).
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Affiliation(s)
- Morgan Cencer
- Departments of †Chemistry and ‡Biomedical Engineering, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Meridith Murley
- Departments of †Chemistry and ‡Biomedical Engineering, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Yuan Liu
- Departments of †Chemistry and ‡Biomedical Engineering, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Bruce P. Lee
- Departments of †Chemistry and ‡Biomedical Engineering, Michigan Technological University, Houghton, Michigan 49931, United States
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A Review of the Role of the Partial Pressure of Carbon Dioxide in Mechanically Loaded Tissues: The Canary in the Cage Singing in Tune with the Pressure Ulcer Mantra. Ann Biomed Eng 2014; 43:336-47. [DOI: 10.1007/s10439-014-1233-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 12/17/2014] [Indexed: 10/24/2022]
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Cencer M, Liu Y, Winter A, Murley M, Meng H, Lee BP. Effect of pH on the rate of curing and bioadhesive properties of dopamine functionalized poly(ethylene glycol) hydrogels. Biomacromolecules 2014; 15:2861-9. [PMID: 25010812 PMCID: PMC4130238 DOI: 10.1021/bm500701u] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 07/09/2014] [Indexed: 12/20/2022]
Abstract
The remarkable underwater adhesion strategy employed by mussels has inspired bioadhesives that have demonstrated promise in connective tissue repair, wound closure, and local delivery of therapeutic cells and drugs. While the pH of oxygenated blood and internal tissues is typically around 7.4, skin and tumor tissues are significantly more acidic. Additionally, blood loss during surgery and ischemia can lead to dysoxia, which lowers pH levels of internal tissues and organs. Using 4-armed PEG end-capped with dopamine (PEG-D) as a model adhesive polymer, the effect of pH on the rate of intermolecular cross-linking and adhesion to biological substrates of catechol-containing adhesives was determined. Adhesive formulated at an acidic pH (pH 5.7-6.7) demonstrated reduced curing rate, mechanical properties, and adhesive performance to pericardium tissues. Although a faster curing rate was observed at pH 8, these adhesives also demonstrated reduced mechanical and bioadhesive properties when compared to adhesives buffered at pH 7.4. Adhesives formulated at pH 7.4 demonstrated a good balance of fast curing rate, elevated mechanical properties and interfacial binding ability. UV-vis spectroscopy evaluation revealed that the stability of the transient oxidation intermediate of dopamine was increased under acidic conditions, which likely reduced the rate of intermolecular cross-linking and bulk cohesive properties for hydrogels formulated at these pH levels. At pH 8, competing cross-linking reaction mechanisms and reduced concentration of dopamine catechol due to auto-oxidation likely reduced the degree of dopamine polymerization and adhesive strength for these hydrogels. pH plays an important role in the adhesive performance of mussel-inspired bioadhesives and the pH of the adhesive formulation needs to be adjusted for the intended application.
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Affiliation(s)
- Morgan Cencer
- Department
of Chemistry and Department of Biomedical Engineering, Michigan
Technological University, Houghton, Michigan 49931, United States
| | - Yuan Liu
- Department
of Chemistry and Department of Biomedical Engineering, Michigan
Technological University, Houghton, Michigan 49931, United States
| | - Audra Winter
- Department
of Chemistry and Department of Biomedical Engineering, Michigan
Technological University, Houghton, Michigan 49931, United States
| | - Meridith Murley
- Department
of Chemistry and Department of Biomedical Engineering, Michigan
Technological University, Houghton, Michigan 49931, United States
| | - Hao Meng
- Department
of Chemistry and Department of Biomedical Engineering, Michigan
Technological University, Houghton, Michigan 49931, United States
| | - Bruce P. Lee
- Department
of Chemistry and Department of Biomedical Engineering, Michigan
Technological University, Houghton, Michigan 49931, United States
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Ellerby GEC, Smith CP, Zou F, Scott P, Soller BR. Validation of a spectroscopic sensor for the continuous, noninvasive measurement of muscle oxygen saturation and pH. Physiol Meas 2013; 34:859-71. [PMID: 23859848 DOI: 10.1088/0967-3334/34/8/859] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
New patient monitoring technologies can noninvasively and directly provide an assessment of the adequacy of tissue perfusion through the simultaneous determination of muscle oxygen saturation (SmO2) and muscle pH (pHm). Non-pulsatile near infrared spectroscopy is used to determine these microvascular parameters. Two separate studies were conducted using an isolated perfused swine limb preparation to widely vary venous blood oxygen saturation (SviO2) and pH (pHvi) to assess the accuracy of a noninvasive sensor with the capability to simultaneously measure both parameters. The isolated limb model is necessary to establish equilibrium between the venous output of the perfusion circuit and the venule measurement of the spectroscopic sensor. The average absolute difference between SmO2 and SviO2 determined over 50 conditions of SviO2 between 13% and 83% on 3 pig limbs was 3.8% and the coefficient of determination (R(2)) was 0.95. The average absolute difference between pHm and pHvi determined over 69 conditions of pHvi between pHvi 6.9 and pHvi 7.5 on 3 pig limbs was 0.045 pH units with an R(2) of 0.92. Measured accuracy was acceptable to support clinically relevant decision making for the assessment of impaired tissue perfusion and acidosis. Sensors were also evaluated on human subjects. There was no statistical difference in SmO2 by gender or location when multiple sensors were evaluated on the right and left calf, deltoid, and thigh of resting men and women (N = 33). SmO2 precision for subjects at rest was 5.6% over the six locations with four different sensors.
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Affiliation(s)
- G E C Ellerby
- Reflectance Medical Inc., 116 Flanders Road, Suite 1000, Westborough, MA 01581, USA
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10
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Oxygen transport characterization of a human model of progressive hemorrhage. Resuscitation 2010; 81:987-93. [PMID: 20418009 DOI: 10.1016/j.resuscitation.2010.03.027] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 03/18/2010] [Accepted: 03/24/2010] [Indexed: 11/23/2022]
Abstract
BACKGROUND Hemorrhage continues to be a leading cause of death from trauma sustained both in combat and in the civilian setting. New models of hemorrhage may add value in both improving our understanding of the physiologic responses to severe bleeding and as platforms to develop and test new monitoring and therapeutic techniques. We examined changes in oxygen transport produced by central volume redistribution in humans using lower body negative pressure (LBNP) as a potential mimetic of hemorrhage. METHODS AND RESULTS In 20 healthy volunteers, systemic oxygen delivery and oxygen consumption, skeletal muscle oxygenation and oral mucosa perfusion were measured over increasing levels of LBNP to the point of hemodynamic decompensation. With sequential reductions in central blood volume, progressive reductions in oxygen delivery and tissue oxygenation and perfusion parameters were noted, while no changes were observed in systemic oxygen uptake or markers of anaerobic metabolism in the blood (e.g., lactate, base excess). While blood pressure decreased and heart rate increased during LBNP, these changes occurred later than the reductions in tissue oxygenation and perfusion. CONCLUSIONS These findings indicate that LBNP induces changes in oxygen transport consistent with the compensatory phase of hemorrhage, but that a frank state of shock (delivery-dependent oxygen consumption) does not occur. LBNP may therefore serve as a model to better understand a variety of compensatory physiological changes that occur during the pre-shock phase of hemorrhage in conscious humans. As such, LBNP may be a useful platform from which to develop and test new monitoring capabilities for identifying the need for intervention during the early phases of hemorrhage to prevent a patient's progression to overt shock.
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Aspergillus fumigatus survival in alkaline and extreme zinc-limiting environments relies on the induction of a zinc homeostasis system encoded by the zrfC and aspf2 genes. EUKARYOTIC CELL 2009; 9:424-37. [PMID: 20038606 DOI: 10.1128/ec.00348-09] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Aspergillus fumigatus has three zinc transporter-encoding genes whose expression is regulated by both pH and the environmental concentration of zinc. We have previously reported that the zrfA and zrfB genes of A. fumigatus are transcribed at higher levels and are required for fungal growth under acidic zinc-limiting conditions whereas they are dispensable for growth in neutral or alkaline zinc-limiting media. Here we report that the transporter of the zinc uptake system that functions in A. fumigatus growing in neutral or alkaline environments is encoded by zrfC. The transcription of zrfC occurs divergently with respect to the adjacent aspf2 gene, which encodes an immunodominant antigen secreted by A. fumigatus. The two genes-zrfC and aspf2-are required to different extents for fungal growth in alkaline and extreme zinc-limiting media. Indeed, these environmental conditions induce the simultaneous transcription of both genes mediated by the transcriptional regulators ZafA and PacC. ZafA upregulates the expression of zrfC and aspf2 under zinc-limiting conditions regardless of the ambient pH, whereas PacC represses the expression of these genes under acidic growth conditions. Interestingly, the mode of action of PacC for zrfC-aspf2 transcription contrasts with the more widely accepted model for PacC function, according to which under alkaline growth conditions PacC would activate the transcription of alkaline-expressed genes but would repress the transcription of acid-expressed genes. In sum, this report provides a good framework for investigating several important aspects of the biology of species of Aspergillus, including the repression of alkaline genes by PacC at acidic pH and the interrelationship that must exist between tissue pH, metal availability in the host tissue, and fungal virulence.
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Werner C, Riegel J, Wicke M. Slaughter Performance of Four Different Turkey Strains, with Special Focus on the Muscle Fiber Structure and the Meat Quality of the Breast Muscle. Poult Sci 2008; 87:1849-59. [DOI: 10.3382/ps.2007-00188] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Audonnet-Blaise S, Krafft MP, Smani Y, Mertes PM, Marie PY, Labrude P, Longrois D, Menu P. Resuscitation of severe but brief haemorrhagic shock with PFC in rabbits restores skeletal muscle oxygen delivery and does not alter skeletal muscle metabolism. Resuscitation 2006; 70:124-32. [PMID: 16759782 DOI: 10.1016/j.resuscitation.2005.11.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Accepted: 11/01/2005] [Indexed: 11/23/2022]
Abstract
Studies have demonstrated that perfluorocarbon (PFC) emulsions associated with hyperoxia improved whole body oxygen delivery during resuscitation of acute haemorrhagic shock (HS). Nevertheless the microcirculatory effects of PFC and the potential deleterious effects of hyperoxic reperfusion are still of concern. We investigated (i) the ability of a newly formulated, small sized and highly stable PFC emulsion to increase skeletal muscle oxygen delivery and (ii) the effect of hyperoxic reperfusion on skeletal muscle metabolism after a brief period of ischaemia using an original, microdialysis-based method that allowed simultaneous measurement tissue oxygen pressure (PtiO2) and interstitial lactate and pyruvate. These measurements were carried out in anaesthetised and ventilated (FiO2 = 1) rabbits subjected to acute HS (50% of blood volume withdrawal) and either resuscitated with a PFC emulsion diluted with a 5% albumin solution (16.2 g PFC per kg body weight) (n = 10) or with a modified fluid gelatin solution (Gelofusine) (n = 10). We found no difference between the two groups for the haemodynamic and haematological variables (except for the venous oxygen partial pressure). However, a significant difference was observed in the slope of the regression linear relationship exhibited between the mean arterial pressure (MAP) and the PtiO2, PFC group showing a much steeper slope than Gelofusine group. In addition, PtiO2 values increased linearly with decreasing haematocrit (Hct) values in PFC-resuscitated animals and decreased linearly with decreasing Hct values in Gelofusine-resuscitated animals. There were no differences between the two groups concerning the blood and interstitial lactate/pyruvate ratios suggesting no deleterious effect of hyperoxic resuscitation in skeletal muscle. In conclusion these results suggest that resuscitation of severe, but brief, HS with PFC increased skeletal muscle oxygen delivery without measurable deleterious effects.
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Affiliation(s)
- Sandra Audonnet-Blaise
- Laboratoire d'Hématologie et de Physiologie, EA 3452, Faculté de Pharmacie, Université Henri Poincaré, 5 rue Albert Lebrun, B.P. 403, F-54001 Nancy Cedex, France.
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14
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Affiliation(s)
- Carl J Hauser
- Department of Surgery, Division of Trauma, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, NJ 07103, USA.
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Clavijo-Alvarez JA, Sims CA, Menconi M, Shim I, Ochoa C, Puyana JC. Bladder Mucosa pH and Pco2 as a Minimally Invasive Monitor of Hemorrhagic Shock and Resuscitation. ACTA ACUST UNITED AC 2004; 57:1199-209; discussion 1209-10. [PMID: 15625450 DOI: 10.1097/01.ta.0000145484.40534.3b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Continuous monitoring of pH, Pco2, and Po2 using fiberoptic sensor technology has been proposed recently as a clinical monitor of the severity of shock and impaired tissue perfusion. Surrogates of gut tissue perfusion such as gastric tonometry, although cumbersome, have been used to indirectly quantify the degree of gut ischemia. The purpose of this study was to demonstrate the feasibility of monitoring bladder mucosa (BM) and to compare urinary bladder mucosa and proximal jejunum mucosa interstitial pH and Pco2 during hemorrhagic shock and resuscitation. METHODS Eleven male miniature swine (25-35 kg) (control, n = 4; shock, n = 7) underwent jejunal tonometry and cystostomy. A multisensor probe was placed adjacent to the BM. Urine was diverted. Normocarbia was maintained. Animals were hemorrhaged and kept at a mean arterial pressure of 40 mm Hg. When a constant infusion was required to maintain the mean arterial pressure at 40 mm Hg (decompensation), animals were resuscitated with shed blood plus two times the shed volume in lactated Ringer's solution (20 minutes) and observed for 2 hours. RESULTS During decompensation, BM pH values decreased significantly from 7.33 +/- 0.08 to 7.01 +/- 0.2 (p < 0.01) and recovered to 7.11 +/- 0.19 at 120 minutes after completion of resuscitation. During decompensation, BM Pco2 values increased significantly compared with baseline (from 49 +/- 6 mm Hg to 71 +/- 19 mm Hg, p < 0.05) and returned to baseline with resuscitation. Jejunum mucosa and BM interstitial Pco2 correlated throughout shock and resuscitation (r = 0.49). Bland-Altman analysis demonstrated significant differences between jejunum mucosa (intramucosal pH) and BM interstitial pH. CONCLUSION Shock-induced changes in the Pco2 of the BM are comparable to tonometric changes in the gut. These data suggest that continuous fiberoptic multisensor probe monitoring of the BM could potentially provide a minimally invasive method for the assessment of impaired tissue perfusion of the splanchnic circulation during shock and resuscitation.
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Affiliation(s)
- Julio A Clavijo-Alvarez
- Harvard Center for Minimally Invasive Surgery, Center of Integration of Medicine and Innovative Technology, Boston, Massachusetts, USA
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