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Klemcke HG, Calderon ML, Crimmins SL, Ryan KL, Xiang L, Hinojosa-Laborde C. Effects of ketamine analgesia on cardiorespiratory responses and survival to trauma and hemorrhage in rats. J Appl Physiol (1985) 2021; 130:1583-1593. [PMID: 33830812 DOI: 10.1152/japplphysiol.00476.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ketamine is the recommended analgesic on the battlefield for soldiers with hemorrhage, despite a lack of supportive evidence from laboratory or clinical studies. Hence, this study determined the effects of ketamine analgesia on cardiorespiratory responses and survival to moderate (37% blood volume; n = 8/group) or severe hemorrhage (50% blood volume; n = 10/group) after trauma in rats. We used a conscious hemorrhage model with extremity trauma (fibular fracture + soft tissue injury) while measuring mean arterial pressure (MAP), heart rate (HR), and body temperature (Tb) by telemetry, and respiration rate (RR), minute volume (MV), and tidal volume (TV) via whole body plethysmography. Male rats received saline (S) or 5.0 mg/kg ketamine (K) (100 µL/100 g body wt) intra-arterially after trauma and hemorrhage. All rats survived 37% hemorrhage. For 50% hemorrhage, neither survival times [180 min (SD 78) vs. 209 min (SD 66)] nor percent survival (60% vs. 80%) differed between S- and K-treated rats. After 37% hemorrhage, K (compared with S) increased MAP and decreased Tb and MV. After 50% hemorrhage, K (compared with S) increased MAP but decreased HR and MV. K effects on cardiorespiratory function were time dependent, significant but modest, and transient at the analgesic dose given. K effects on Tb were also significant but modest and more prolonged. With the use of this rat model, our data support the use of K as an analgesic in injured, hypovolemic patients.NEW & NOTEWORTHY Ketamine administration at a dose shown to alleviate pain in nonhemorrhaged rats with extremity trauma had only modest and transient effects on multiple aspects of cardiorespiratory function after both moderate (37%) and severe (50%) traumatic hemorrhages. Such effects did not alter survival.
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Affiliation(s)
- Harold G Klemcke
- United States Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - Mariam L Calderon
- United States Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - Stephen L Crimmins
- United States Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - Kathy L Ryan
- United States Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
| | - Lusha Xiang
- United States Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
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Xia W, Huang ZJ, Guo ZL, Feng YW, Zhang CY, He GY, Tang AZ. Plasma volume, cell volume, total blood volume and F factor in the tree shrew. PLoS One 2020; 15:e0234835. [PMID: 32881864 PMCID: PMC7470369 DOI: 10.1371/journal.pone.0234835] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 08/18/2020] [Indexed: 12/21/2022] Open
Abstract
In this study, the physiological values of volumes of plasma, cells, total blood and the F blood factors were identified in 24 adult tree shrews (Tupaia belangeri; 12 male and 12 female; average BW of 123.9±19.19 g). The two-compartment model method of Evans Blue dye was used to obtain the plasma volume and the venous hematocrit was measured by microhematocrit method. To establish the relationship between body weight (BW) and blood volume of tree shrews, We performed linear fitting for these two datasets. Results were analyzed according to gender and weight (<120g vs.>120g). Statistical significance was assessed using the unpaired student t test and one-way ANOVA. The average volumes per 100g body weight of plasma, red blood cell (RBC) and total blood were 5.42±0.543, 3.24±0.445, and 8.66±0.680ml respectively. The mean body hematocrit, cardiac hematocrit, jugular vein hematocrit, femoral vein hematocrit, and tail vein hematocrit was 37.43±4.096, 39.72±3.219, 43.04±4.717, 40.84±3.041, and 38.71±3.442% respectively. The F cardiac was 0.94±0.072, F jugular vein 0.88±0.118, F femoral vein 0.92±0.111, and the F tail vein 0.97±0.117. Blood volume (ml) was 85.89103×BW (kg). This is the first study to provide the parameters of plasma volume, cell volume, total blood volume and F factor and a baseline for future research on blood physiology of tree shrews.
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Affiliation(s)
- Wei Xia
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Ministry of Education, Nanning, Guangxi, China
| | - Zong-jian Huang
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Ministry of Education, Nanning, Guangxi, China
| | - Zhao-liang Guo
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Ministry of Education, Nanning, Guangxi, China
| | - Yi-wei Feng
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Ministry of Education, Nanning, Guangxi, China
| | - Chao-yin Zhang
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Ministry of Education, Nanning, Guangxi, China
| | - Guang-yao He
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Ministry of Education, Nanning, Guangxi, China
- * E-mail: (GH); (AT)
| | - An-zhou Tang
- Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Ministry of Education, Nanning, Guangxi, China
- * E-mail: (GH); (AT)
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Tokunaga A, Miyamoto H, Fumoto S, Nishida K. Effect of renal ischaemia/reperfusion-induced acute kidney injury on pharmacokinetics of midazolam in rats. ACTA ACUST UNITED AC 2019; 71:1792-1799. [PMID: 31579949 DOI: 10.1111/jphp.13167] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/29/2019] [Accepted: 09/01/2019] [Indexed: 12/18/2022]
Abstract
OBJECTIVES This study aimed to investigate the effects of renal ischaemia/reperfusion (I/R)-induced acute kidney injury (AKI) on the distribution of midazolam (MDZ), a probe drug for cytochrome P450 3A (CYP3A) activity. METHODS We established an AKI model inducing ischaemia of both renal pedicles for 60 min followed by 24-h reperfusion. MDZ was administered intravenously (i.v.) to the rats via the jugular vein, and then, blood samples were collected to determine the plasma concentration of MDZ. KEY FINDINGS While the plasma concentration of MDZ after i.v. administration was decreased in the I/R rats, the tissue concentration was not altered. In addition, the tissue-to-plasma (T/P) ratio of MDZ was increased in the I/R rats. The unbound fraction of MDZ and the level of indoxyl sulphate (IS) in plasma were elevated in the I/R rats. Furthermore, the unbound fraction of MDZ was significantly increased by the addition of IS. CONCLUSIONS These results indicated that the displacement of albumin-bound MDZ by IS changed the unbound fraction of MDZ and elevated the T/P ratio of MDZ in I/R rats.
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Affiliation(s)
- Ayako Tokunaga
- Department of Pharmaceutics, Graduate, School of Biomedical Science, Nagasaki University, Nagasaki, Japan
| | - Hirotaka Miyamoto
- Department of Pharmaceutics, Graduate, School of Biomedical Science, Nagasaki University, Nagasaki, Japan
| | - Shintaro Fumoto
- Department of Pharmaceutics, Graduate, School of Biomedical Science, Nagasaki University, Nagasaki, Japan
| | - Koyo Nishida
- Department of Pharmaceutics, Graduate, School of Biomedical Science, Nagasaki University, Nagasaki, Japan
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Weber B, Lackner I, Haffner-Luntzer M, Palmer A, Pressmar J, Scharffetter-Kochanek K, Knöll B, Schrezenemeier H, Relja B, Kalbitz M. Modeling trauma in rats: similarities to humans and potential pitfalls to consider. J Transl Med 2019; 17:305. [PMID: 31488164 PMCID: PMC6728963 DOI: 10.1186/s12967-019-2052-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 08/29/2019] [Indexed: 12/27/2022] Open
Abstract
Trauma is the leading cause of mortality in humans below the age of 40. Patients injured by accidents frequently suffer severe multiple trauma, which is life-threatening and leads to death in many cases. In multiply injured patients, thoracic trauma constitutes the third most common cause of mortality after abdominal injury and head trauma. Furthermore, 40-50% of all trauma-related deaths within the first 48 h after hospital admission result from uncontrolled hemorrhage. Physical trauma and hemorrhage are frequently associated with complex pathophysiological and immunological responses. To develop a greater understanding of the mechanisms of single and/or multiple trauma, reliable and reproducible animal models, fulfilling the ethical 3 R's criteria (Replacement, Reduction and Refinement), established by Russell and Burch in 'The Principles of Human Experimental Technique' (published 1959), are required. These should reflect both the complex pathophysiological and the immunological alterations induced by trauma, with the objective to translate the findings to the human situation, providing new clinical treatment approaches for patients affected by severe trauma. Small animal models are the most frequently used in trauma research. Rattus norvegicus was the first mammalian species domesticated for scientific research, dating back to 1830. To date, there exist numerous well-established procedures to mimic different forms of injury patterns in rats, animals that are uncomplicated in handling and housing. Nevertheless, there are some physiological and genetic differences between humans and rats, which should be carefully considered when rats are chosen as a model organism. The aim of this review is to illustrate the advantages as well as the disadvantages of rat models, which should be considered in trauma research when selecting an appropriate in vivo model. Being the most common and important models in trauma research, this review focuses on hemorrhagic shock, blunt chest trauma, bone fracture, skin and soft-tissue trauma, burns, traumatic brain injury and polytrauma.
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Affiliation(s)
- Birte Weber
- Department of Traumatology, Hand-, Plastic-, and Reconstructive Surgery, Center of Surgery, University of Ulm Medical School, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | - Ina Lackner
- Department of Traumatology, Hand-, Plastic-, and Reconstructive Surgery, Center of Surgery, University of Ulm Medical School, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | - Melanie Haffner-Luntzer
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | - Annette Palmer
- Institute of Clinical and Experimental Trauma-Immunology, University of Ulm, Ulm, Germany
| | - Jochen Pressmar
- Department of Traumatology, Hand-, Plastic-, and Reconstructive Surgery, Center of Surgery, University of Ulm Medical School, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | | | - Bernd Knöll
- Institute of Physiological Chemistry, University of Ulm, Ulm, Germany
| | - Hubert Schrezenemeier
- Institute of Transfusion Medicine, University of Ulm and Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service Baden-Württemberg – Hessen and University Hospital Ulm, Ulm, Germany
| | - Borna Relja
- Department of Trauma, Hand and Reconstructive Surgery, Goethe University Frankfurt, Frankfurt, Germany
- Department of Radiology and Nuclear Medicine, Experimental Radiology, Otto-von-Guericke University, Magdeburg, Germany
| | - Miriam Kalbitz
- Department of Traumatology, Hand-, Plastic-, and Reconstructive Surgery, Center of Surgery, University of Ulm Medical School, Albert-Einstein-Allee 23, 89081 Ulm, Germany
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Richalet JP, Marchant D, Macarlupu JL, Voituron N. Modeling the Evans Blue Dilution Method for the Measurement of Plasma Volume in Small Animals: A New Optimized Method. Ann Biomed Eng 2018; 46:2189-2195. [PMID: 30136152 DOI: 10.1007/s10439-018-02114-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/10/2018] [Indexed: 11/28/2022]
Abstract
The measurement of plasma volume (Vp) in humans and animals is frequently performed by the Evans blue dye dilution method. However, after injection of Evans blue into the circulation, no steady state is observed because of delayed mixing and progressive leakage of dye out of vascular space. Various methods of calculation have been proposed, either with a single blood sampling 5-10 min after dye injection (Single point method), or with extrapolation at time zero of a logarithmic decay (Log linear method). We propose a method based on a two-compartment hypothesis taking into account the initial mixing and the leakage phase in the time course of dye concentration. Nineteen Sprague-Dawley rats were studied in various conditions and blood sampling was performed before and 2, 4 and 6 min after injection of 200 μg Evans blue. A mathematical model was designed to describe the two-compartment hypothesis and allowed the calculation of Vp and Kout (rate of disappearance of dye from vascular space). A Bland and Altman representation evidenced an overestimation of Vp with previous methods and the great dispersion of results with the single point method, especially when using the 6 min point. Calculation of Kout revealed more accurate with the model than the Log linear method, especially when the mixing rate is slow. We suggest using the two-compartment model to measure Vp with Evans blue technique in rats. This method also allows precise evaluation of the rate of dye leakage, which could be a good marker of vascular permeability to albumin.
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Affiliation(s)
- Jean-Paul Richalet
- Laboratoire "Hypoxie et poumon" EA2363, Université Paris 13, 74 rue Marcel Cachin, 93017, Bobigny Cedex, France. .,Laboratoire d'excellence, GReX, Paris, France.
| | - Dominique Marchant
- Laboratoire "Hypoxie et poumon" EA2363, Université Paris 13, 74 rue Marcel Cachin, 93017, Bobigny Cedex, France
| | - Jose-Luis Macarlupu
- Laboratorio de Fisiologia Comparada, Universidad Cayetano Heredia, Lima, Peru
| | - Nicolas Voituron
- Laboratoire "Hypoxie et poumon" EA2363, Université Paris 13, 74 rue Marcel Cachin, 93017, Bobigny Cedex, France.,Laboratoire d'excellence, GReX, Paris, France
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Abstract
Trauma mortality may be increased in the presence of preexisting diseases such as chronic hypertension. We hypothesized that systemic and microvascular alterations accompanying chronic hypertension would increase the vulnerability to hemorrhage relative to normotensive controls in a rat model of hemorrhagic shock. We present a novel comparative hemorrhage model of shock vulnerability, quantified by "vulnerability curves" expressing physiological response to hemorrhage as a function of three matched shock metrics: cumulative blood volume, mean arterial pressure (MAP), and oxygen delivery (Do2). Responses were central hemodynamics and respiratory and muscle oxygenation obtained for one hypertensive (spontaneously hypertensive [SHR]) and two normotensive (Sprague-Dawley, Wistar-Kyoto) rat strains. Hemorrhagic shock was induced by incremental (0.5 mL) hemorrhage to cardiovascular collapse in anesthetized and mechanically ventilated animals. Shock vulnerability of SHR rats was primarily pressure-driven; in general, SHR exhibited the expected patterns of more rapid deterioration in MAP and Vo2 over smaller ranges of blood loss and Do2. Sternotomy-related depression of CO and thus Do2 in SHR meant that we could not test hypotheses related to the role of Do2 and contribution to perfusion differences between normotensive and hypertensive subjects. Insensitivity of lactate to strain effects suggests that lactate may be a reliable biomarker of shock status. Unexpected similarities between Wistar-Kyoto and SHR suggest strain-related effects other than those related to hypertension per se contribute to hemorrhage response; body size effects and genetic relationships could not be ruled out. Future studies should incorporate phylogenetically based methods to examine the role of hypertension and physiological response to hemorrhage across multiple strains.
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Rose R, Kheirabadi BS, Klemcke HG. Arterial blood gases, electrolytes, and metabolic indices associated with hemorrhagic shock: inter- and intrainbred rat strain variation. J Appl Physiol (1985) 2013; 114:1165-73. [PMID: 23471949 DOI: 10.1152/japplphysiol.01293.2012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have previously shown interstrain variation (indicating a genetic basis), and intrastrain variation in survival time after hemorrhage (STaH) among inbred rat strains. To assist in understanding physiological mechanisms associated with STaH, we analyzed various arterial blood measures (ABM; pH, Paco2, oxygen content, sodium, potassium, glucose, bicarbonate, base excess, total CO2, and ionized calcium) in inbred rats. Rats from five inbred strains (n = 8-10/strain) were catheterized and, ≈ 24 h later, subjected to a conscious, controlled, 47% hemorrhage. ABM were measured at the start (initial) and end (final) of hemorrhage. Inter- and intrainbred strain variations of ABM were quantified and compared, and correlations of ABM with STaH were determined. All final ABM values and some initial ABM values were different among strains. Most ABM changed (Δ) during hemorrhage, and these changes differed among strains (P <0.03). Some strain-dependent correlations (r ≥ 0.7; P ≤ 0.05) existed between ΔABM and STaH (e.g., BN/Mcwi, ΔK(+), r = -0.84). Dark Agouti rats (longest STaH) had the smallest ΔPaco2, ΔHCO3(-), and Δbase excess, and the highest final glucose. High coefficients of variation (CVs, >10%), strain-specific CVs, and low intraclass correlation coefficients (rI < 0.5) defined the large intrastrain ABM variation that exceeded interstrain variation for most ABM. These results suggest that some ABM (K(+), Paco2, glucose, oxygen content) could predict subsequent STaH in an inbred rat strain-dependent manner. We speculate that whereas genetic differences may be responsible for interstrain variation, individual-specific epigenetic processes (e.g., DNA methylation) may be partly responsible for both inter- and intrastrain ABM variation.
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Affiliation(s)
- Rajiv Rose
- U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas 78234, USA
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Klemcke HG, DeKroon RM, Mocanu M, Robinette JB, Alzate O. Cardiac mitochondrial proteomic expression in inbred rat strains divergent in survival time after hemorrhage. Physiol Genomics 2013; 45:243-55. [PMID: 23386204 DOI: 10.1152/physiolgenomics.00118.2012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We have previously identified inbred rat strains differing in survival time to a severe controlled hemorrhage (StaH). In efforts to identify cellular mechanisms and ultimately genes that are important contributors to enhanced STaH, we conducted a study to characterize potential differences in cardiac mitochondrial proteins in these rats. Inbred rats from three strains [Brown Norway/Medical College of Wisconsin (BN); Dark Agouti (DA), and Fawn Hooded Hypertensive (FHH)] with different StaH (DA = FHH > BN) were assigned to one of three treatment groups (n = 4/strain): nonoperated controls, surgically catheterized rats, or rats surgically catheterized and hemorrhaged 24 h postsurgery. Rats were euthanized 30 min after handling or 30 min after initiation of a 26 min hemorrhage. After euthanasia, hearts were removed and mitochondria isolated. Differential protein expression was determined using 2D DIGE-based Quantitative Intact Proteomics and proteins identified by MALDI/TOF mass spectrometry. Hundreds of proteins (791) differed among inbred rat strains (P ≤ 0.038), and of these 81 were identified. Thirty-eight were unique proteins and 43 were apparent isoforms. For DA rats (longest STaH), 36 proteins increased and 30 decreased compared with BN (shortest STaH). These 81 proteins were associated with lipid (e.g., acyl CoA dehydrogenase) and carbohydrate (e.g., fumarase) metabolism, oxidative phosphorylation (e.g., ubiquinol-cytochrome C reductase), ATP synthesis (F1 ATPase), and H2S synthesis (3-mercaptopyruvate sulfurtransferase). Although we cannot make associations between these identified mitochondrial proteins and StaH, our data do provide evidence for future candidate proteins with which to consider such associations.
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Affiliation(s)
- Harold G Klemcke
- U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas 78234, USA.
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Ryan KL, Rickards CA, Hinojosa-Laborde C, Cooke WH, Convertino VA. Sympathetic responses to central hypovolemia: new insights from microneurographic recordings. Front Physiol 2012; 3:110. [PMID: 22557974 PMCID: PMC3337468 DOI: 10.3389/fphys.2012.00110] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 04/03/2012] [Indexed: 11/13/2022] Open
Abstract
Hemorrhage remains a major cause of mortality following traumatic injury in both military and civilian settings. Lower body negative pressure (LBNP) has been used as an experimental model to study the compensatory phase of hemorrhage in conscious humans, as it elicits central hypovolemia like that induced by hemorrhage. One physiological compensatory mechanism that changes during the course of central hypovolemia induced by both LBNP and hemorrhage is a baroreflex-mediated increase in muscle sympathetic nerve activity (MSNA), as assessed with microneurography. The purpose of this review is to describe recent results obtained using microneurography in our laboratory as well as those of others that have revealed new insights into mechanisms underlying compensatory increases in MSNA during progressive reductions in central blood volume and how MSNA is altered at the point of hemodynamic decompensation. We will also review recent work that has compared direct MSNA recordings with non-invasive surrogates of MSNA to determine the appropriateness of using such surrogates in assessing the clinical status of hemorrhaging patients.
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Affiliation(s)
- Kathy L Ryan
- U.S. Army Institute of Surgical Research Fort Sam Houston, TX, USA11
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Hinojosa-Laborde C, Rickards CA, Ryan KL, Convertino VA. Heart Rate Variability during Simulated Hemorrhage with Lower Body Negative Pressure in High and Low Tolerant Subjects. Front Physiol 2011; 2:85. [PMID: 22125539 PMCID: PMC3221414 DOI: 10.3389/fphys.2011.00085] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 11/01/2011] [Indexed: 11/30/2022] Open
Abstract
Heart rate variability (HRV) decreases during hemorrhage, and has been proposed as a new vital sign to assess cardiovascular stability in trauma patients. The purpose of this study was to determine if any of the HRV metrics could accurately distinguish between individuals with different tolerance to simulated hemorrhage. Specifically, we hypothesized that (1) HRV would be similar in low tolerant (LT) and high tolerant (HT) subjects at presyncope when both groups are on the verge of hemodynamic collapse; and (2) HRV could distinguish LT subjects at presyncope from hemodynamically stable HT subjects (i.e., at a submaximal level of hypovolemia). Lower body negative pressure (LBNP) was used as a model of hemorrhage in healthy human subjects, eliciting central hypovolemia to the point of presyncopal symptoms (onset of hemodynamic collapse). Subjects were classified as LT if presyncopal symptoms occurred during the −15 to −60 mmHg levels of LBNP, and HT if symptoms occurred after LBNP of −60 mmHg. A total of 20 HRV metrics were derived from R–R interval measurements at the time of presyncope, and at one level prior to presyncope (submax) in LT and HT groups. Only four HRV metrics (Long-range Detrended Fluctuation Analysis, Forbidden Words, Poincaré Plot Descriptor Ratio, and Fractal Dimensions by Curve Length) supported both hypotheses. These four HRV metrics were evaluated further for their ability to identify individual LT subjects at presyncope when compared to HT subjects at submax. Variability in individual LT and HT responses was so high that LT responses overlapped with HT responses by 85–97%. The sensitivity of these HRV metrics to distinguish between individual LT from HT subjects was 6–33%, and positive predictive values were 40–73%. These results indicate that while a small number of HRV metrics can accurately distinguish between LT and HT subjects using group mean data, individual HRV values are poor indicators of tolerance to hypovolemia.
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Klemcke HG, Joe B, Rose R, Ryan KL. Life or death? A physiogenomic approach to understand individual variation in responses to hemorrhagic shock. Curr Genomics 2011; 12:428-42. [PMID: 22379396 PMCID: PMC3178911 DOI: 10.2174/138920211797248574] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 06/29/2011] [Accepted: 07/06/2011] [Indexed: 11/22/2022] Open
Abstract
Severe hemorrhage due to trauma is a major cause of death throughout the world. It has often been observed that some victims are able to withstand hemorrhage better than others. For decades investigators have attempted to identify physiological mechanisms that distinguish survivors from nonsurvivors for the purpose of providing more informed therapies. As an alternative approach to address this issue, we have initiated a research program to identify genes and genetic mechanisms that contribute to this phenotype of survival time after controlled hemorrhage. From physiogenomic studies using inbred rat strains, we have demonstrated that this phenotype is a heritable quantitative trait, and is therefore a complex trait regulated by multiple genes. Our work continues to identify quantitative trait loci as well as potential epigenetic mechanisms that might influence survival time after severe hemorrhage. Our ultimate goal is to improve survival to traumatic hemorrhage and attendant shock via regulation of genetic mechanisms and to provide knowledge that will lead to genetically-informed personalized treatments.
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Affiliation(s)
- Harold G Klemcke
- U.S. Army Institute of Surgical Research, Fort Sam Houston, TX 78234, USA
| | - Bina Joe
- Physiological Genomics Laboratory, Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH 43614, USA
| | - Rajiv Rose
- U.S. Army Institute of Surgical Research, Fort Sam Houston, TX 78234, USA
| | - Kathy L Ryan
- U.S. Army Institute of Surgical Research, Fort Sam Houston, TX 78234, USA
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