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Semenov YS, Melnikov IS, Luzhnov PV, Dyachenko AI. Oscillations of Hemodynamic Parameters Induced by Negative Pressure Breathing in Healthy Humans. Aerosp Med Hum Perform 2024; 95:297-304. [PMID: 38790119 DOI: 10.3357/amhp.6419.2024] [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: 05/26/2024]
Abstract
INTRODUCTION: Negative pressure breathing is breathing with decreased pressure in the respiratory tract without lowering pressure acting on the torso. We lowered air pressure only during inspiration (NPBin). NPBin, used to increase venous return to the heart, is considered a countermeasure against redistribution of body fluids toward the head during spaceflight. We studied NPBin effects on circulation in healthy humans with an emphasis on NPBin-induced oscillations of hemodynamic parameters synchronous with breathing. We propose an approach to analyze the oscillations based on coherent averaging.METHODS: Eight men ages 24-42 yr participated in the NPBin and control series. During the series, to reproduce fluids shift observed under microgravity, subjects were supine and head down (-8°). Duration of NPBin was 20 min, rarefaction -20 cm H₂O. Hemodynamic parameters were measured by Finometer. Electrical impedance measurements were used to estimate changes in blood filling of cerebral vessels.RESULTS: Mean values of hemodynamic parameters virtually did not change under NPBin, but NPBin induced oscillations of the parameters synchronous with respiration. Peak-to-peak amplitude under NPBin were: mean arterial pressure, 4 ± 1 (mmHg); stroke volume, 7 ± 3 (mL); and heart rate, 4 ± 1 (bpm). Electrical impedance of the head increased during inspiration. The increase under NPBin was three times greater than under normal breathing.DISCUSSION: Analysis of oscillations gives more information than analysis of mean values. NPBin induces short-term decrease in left ventricle stroke volume and arterial blood pressure during each inspiration; the decrease is compensated by increase after inspiration. NPBin facilitates redistribution of body fluids away from the head.Semenov YS, Melnikov IS, Luzhnov PV, Dyachenko AI. Oscillations of hemodynamic parameters induced by negative pressure breathing in healthy humans. Aerosp Med Hum Perform. 2024; 95(6):297-304.
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Goto A, Kambayashi R, Hagiwara-Nagasawa M, Izumi-Nakaseko H, Takei Y, Kawai S, Matsumoto A, Lurie KG, Sugiyama A. Impact of head-up tilt on expiratory negative airway pressure ventilation-induced cardiovascular hemodynamics in the halothane-anesthetized intact microminipigs. Heart Vessels 2022; 37:1808-1815. [DOI: 10.1007/s00380-022-02068-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 03/31/2022] [Indexed: 11/28/2022]
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Hansen AB, Lawley JS, Rickards CA, Howden EJ, Sarma S, Cornwell WK, Amin SB, Mugele H, Marume K, Possnig C, Whitworth LA, Williams MA, Levine BD. Reducing intracranial pressure by reducing central venous pressure: assessment of potential countermeasures to spaceflight-associated neuro-ocular syndrome. J Appl Physiol (1985) 2020; 130:283-289. [PMID: 33270516 DOI: 10.1152/japplphysiol.00786.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Spaceflight-associated neuro-ocular syndrome (SANS) involves unilateral or bilateral optic disc edema, widening of the optic nerve sheath, and posterior globe flattening. Owing to posterior globe flattening, it is hypothesized that microgravity causes a disproportionate change in intracranial pressure (ICP) relative to intraocular pressure. Countermeasures capable of reducing ICP include thigh cuffs and breathing against inspiratory resistance. Owing to the coupling of central venous pressure (CVP) and intracranial pressure, we hypothesized that both ICP and CVP will be reduced during both countermeasures. In four male participants (32 ± 13 yr) who were previously implanted with Ommaya reservoirs for treatment of unrelated clinical conditions, ICP was measured invasively through these ports. Subjects were healthy at the time of testing. CVP was measured invasively by a peripherally inserted central catheter. Participants breathed through an impedance threshold device (ITD, -7 cmH2O) to generate negative intrathoracic pressure for 5 min, and subsequently, wore bilateral thigh cuffs inflated to 30 mmHg for 2 min. Breathing through an ITD reduced both CVP (6 ± 2 vs. 3 ± 1 mmHg; P = 0.02) and ICP (16 ± 3 vs. 12 ± 1 mmHg; P = 0.04) compared to baseline, a result that was not observed during the free breathing condition (CVP, 6 ± 2 vs. 6 ± 2 mmHg, P = 0.87; ICP, 15 ± 3 vs. 15 ± 4 mmHg, P = 0.68). Inflation of the thigh cuffs to 30 mmHg caused no meaningful reduction in CVP in all four individuals (5 ± 4 vs. 5 ± 4 mmHg; P = 0.1), coincident with minimal reduction in ICP (15 ± 3 vs. 14 ± 4 mmHg; P = 0.13). The application of inspiratory resistance breathing resulted in reductions in both ICP and CVP, likely due to intrathoracic unloading.NEW & NOTEWORTHY Spaceflight causes pathological changes in the eye that may be due to the absence of gravitational unloading of intracranial pressure (ICP) under microgravity conditions commonly referred to as spaceflight-associated neuro-ocular syndrome (SANS), whereby countermeasures aimed at lowering ICP are necessary. These data show that impedance threshold breathing acutely reduces ICP via a reduction in central venous pressure (CVP). Whereas, acute thigh cuff inflation, a popular known spaceflight-associated countermeasure, had little effect on ICP and CVP.
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Affiliation(s)
- Alexander B Hansen
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Justin S Lawley
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria.,Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, Texas.,University of Texas Southwestern Medical Center, Dallas, Texas
| | - Caroline A Rickards
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Erin J Howden
- The Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Satyam Sarma
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, Texas.,University of Texas Southwestern Medical Center, Dallas, Texas
| | - William K Cornwell
- Division of Cardiology, Department of Internal Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Sachin B Amin
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Hendrik Mugele
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Kyohei Marume
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Carmen Possnig
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | | | - Michael A Williams
- Departments of Neurology and Neurological Surgery, University of Washington School of Medicine, Seattle, Washington
| | - Benjamin D Levine
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, Texas.,University of Texas Southwestern Medical Center, Dallas, Texas
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Impact of Altered Airway Pressure on Intracranial Pressure, Perfusion, and Oxygenation: A Narrative Review. Crit Care Med 2019; 47:254-263. [PMID: 30653472 DOI: 10.1097/ccm.0000000000003558] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES A narrative review of the pathophysiology linking altered airway pressure and intracranial pressure and cerebral oxygenation. DATA SOURCES Online search of PubMed and manual review of articles (laboratory and patient studies) of the altered airway pressure on intracranial pressure, cerebral perfusion, or cerebral oxygenation. STUDY SELECTION Randomized trials, observational and physiologic studies. DATA EXTRACTION Our group determined by consensus which resources would best inform this review. DATA SYNTHESIS In the normal brain, positive-pressure ventilation does not significantly alter intracranial pressure, cerebral oxygenation, or perfusion. In injured brains, the impact of airway pressure on intracranial pressure is variable and determined by several factors; a cerebral venous Starling resistor explains much of the variability. Negative-pressure ventilation can improve cerebral perfusion and oxygenation and reduce intracranial pressure in experimental models, but data are limited, and mechanisms and clinical benefit remain uncertain. CONCLUSIONS The effects of airway pressure and ventilation on cerebral perfusion and oxygenation are increasingly understood, especially in the setting of brain injury. In the face of competing mechanisms and priorities, multimodal monitoring and individualized titration will increasingly be required to optimize care.
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Winklewski PJ, Wolf J, Gruszecki M, Wszedybyl-Winklewska M, Narkiewicz K. Current understanding of the effects of inspiratory resistance on the interactions between systemic blood pressure, cerebral perfusion, intracranial pressure, and cerebrospinal fluid dynamics. J Appl Physiol (1985) 2019; 127:1206-1214. [DOI: 10.1152/japplphysiol.00058.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Negative intrathoracic pressure (nITP) is generated by the respiratory muscles during inspiration to overcome inspiratory resistance, thus enabling lung ventilation. Recently developed noninvasive techniques have made it possible to assess the effects of nITP in real time in several physiological aspects such as systemic blood pressure (BP), intracranial pressure (ICP), and cerebral blood flow (CBF). It has been shown that nITP from 0 to −20 cmH2O elevates BP and diminishes ICP, which facilitates brain perfusion. The effects of nITP from −20 to −40 cmH2O on BP, ICP, and CBF remain largely unrecognized, yet even nITP at −40 cmH2O may facilitate CBF by diminishing ICP. Importantly, nITP from −20 to −40 cmH2O has been documented in adults in commonly encountered obstructive sleep apnea, which justifies research in this area. Recent revelations about interactions between ICP and BP have opened up new fields of research in physiological regulation and the pathophysiology of common diseases, such as hypertension, brain injury, and respiratory disorders. A better understanding of these interactions may translate directly into new therapies in various fields of clinical medicine.
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Affiliation(s)
- Pawel J. Winklewski
- Department of Human Physiology, Medical University of Gdansk, Gdansk, Poland
- Department of Clinical Anatomy and Physiology, Pomeranian University of Slupsk, Slupsk, Poland
| | - Jacek Wolf
- Department of Hypertension and Diabetology, Medical University of Gdansk, Gdansk, Poland
| | - Marcin Gruszecki
- Department of Radiology Informatics and Statistics, Medical University of Gdansk, Gdansk, Poland
| | | | - Krzysztof Narkiewicz
- Department of Hypertension and Diabetology, Medical University of Gdansk, Gdansk, Poland
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Favilla CG, Forti RM, Zamzam A, Detre JA, Mullen MT, Yodh AG, Kasner SE, Busch DR, Baker WB, Mesquita RC, Kung D, Messé SR. Perfusion Enhancement with Respiratory Impedance After Stroke (PERI-Stroke). Neurotherapeutics 2019; 16:1296-1303. [PMID: 31140115 PMCID: PMC6985403 DOI: 10.1007/s13311-019-00744-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Intrathoracic pressure influences cardiac output and may affect cerebral blood flow (CBF). We aimed to quantify the cerebral hemodynamic response to intrathoracic pressure reduction in patients with acute ischemic stroke using a noninvasive respiratory impedance (RI) device. We assessed low-level (6 cm H2O) and high-level (12 cm H2O) RI in 17 spontaneously breathing patients within 72 h of anterior circulation acute ischemic stroke. Average age was 65 years, and 35% were female. Frontal lobe tissue perfusion and middle cerebral artery velocity (MCAv) were continuously monitored with optical diffuse correlation spectroscopy (DCS) and transcranial Doppler ultrasound, respectively. High-level RI resulted in a 7% increase in MCAv (p = 0.004). MCAv varied across all studied levels (baseline vs low-level vs high-level, p = 0.006), with a significant test of trend (p = 0.002). Changes were not seen in DCS measured tissue perfusion by nonparametric pairwise comparison. Mixed effects regression analysis identified a small increase in both MCAv (low-level RI: β 2.1, p < 0.001; high-level RI: β 5.0, p < 0.001) and tissue-level flow (low-level RI: β 5.4, p < 0.001; high-level RI: β 5.9, p < 0.001). There was a small increase in mean arterial pressure during low-level and high-level RI, 4% (p = 0.013) and 4% (p = 0.017), respectively. End-tidal CO2 remained stable throughout the protocol. RI was well tolerated. Manipulating intrathoracic pressure via noninvasive RI was safe and produced a small but measurable increase in cerebral perfusion in acute ischemic stroke patients. Future studies are warranted to assess whether RI is feasible and tolerable for prolonged use in hyperacute stroke management.
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Affiliation(s)
- Christopher G Favilla
- Department of Neurology, University of Pennsylvania, Philadelphia, USA.
- Department of Neurology, Hospital of the University of Pennsylvania, 3400 Spruce St, 3 West Gates, Philadelphia, PA, 19104-4283, USA.
| | - Rodrigo M Forti
- Department of Physics & Astronomy, University of Pennsylvania, Philadelphia, USA
- Institute of Physics, University of Campinas, Campinas, 13083-859, Brazil
- Brazilian Institute of Neuroscience and Neurotechnology, Campinas, 13083-888, Brazil
| | - Ahmad Zamzam
- Department of Neurology, University of Pennsylvania, Philadelphia, USA
| | - John A Detre
- Department of Neurology, University of Pennsylvania, Philadelphia, USA
- Department of Radiology, University of Pennsylvania, Philadelphia, USA
| | - Michael T Mullen
- Department of Neurology, University of Pennsylvania, Philadelphia, USA
| | - Arjun G Yodh
- Department of Physics & Astronomy, University of Pennsylvania, Philadelphia, USA
| | - Scott E Kasner
- Department of Neurology, University of Pennsylvania, Philadelphia, USA
| | - David R Busch
- Department of Physics & Astronomy, University of Pennsylvania, Philadelphia, USA
- Department of Anesthesiology & Pain Management, University of Texas Southwestern, Dallas, USA
- Department Neurology & Neurotherapeutics, University of Texas Southwestern, Dallas, USA
| | - Wesley B Baker
- Department of Physics & Astronomy, University of Pennsylvania, Philadelphia, USA
- Department of Neurology, Children's Hospital of Philadelphia, Philadelphia, USA
| | - Rickson C Mesquita
- Institute of Physics, University of Campinas, Campinas, 13083-859, Brazil
- Brazilian Institute of Neuroscience and Neurotechnology, Campinas, 13083-888, Brazil
| | - David Kung
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - Steven R Messé
- Department of Neurology, University of Pennsylvania, Philadelphia, USA
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Riess ML, Balzer C. Mechanical adjuncts for cardiocerebral resuscitation. Expert Rev Med Devices 2019; 16:771-776. [PMID: 31353970 DOI: 10.1080/17434440.2019.1649135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Introduction: Cardiac arrest remains a worldwide health problem with very poor outcome. In the absence of bystander resuscitation, survival rates decrease by 10% per minute of arrest and global ischemia. Even the best manual chest compressions, however, can only produce a fraction of normal cardiac output and blood flow to vital organs. Physiological principles and current evidence for the use of mechanical devices to increase survival and quality of life after cardiac arrest are highlighted in this review article. Areas covered: Mechanical adjuncts such as the Active Compression Decompression device, automated chest compressors and the use of a negative pressure valve (Impedance Threshold Device) can synergistically aid in improving quality of CPR and increasing cardiac output and vital organ perfusion. Expert opinion: The current conclusions that the use of mechanical adjunct devices in a preclinical setting is not recommended or neutral at best, need to be reevaluated, especially with regard to new advanced and promising treatments that require prolonged high-quality CPR during the transport to a hospital to improve the outcome of patients.
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Affiliation(s)
- Matthias L Riess
- Division of Anesthesiology, TVHS VA Medical Center , Nashville , TN , USA.,Departments of Anesthesiology and Pharmacology, Vanderbilt University Medical Center , Nashville , TN , USA
| | - Claudius Balzer
- Department of Anesthesiology, Vanderbilt University Medical Center , Nashville , TN , USA.,Department of Anesthesiology, University of Greifswald , Greifswald , Germany
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8
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Rickards CA. Vive la résistance! The role of inspiratory resistance breathing on cerebral blood flow. Respir Physiol Neurobiol 2019; 265:76-82. [DOI: 10.1016/j.resp.2018.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 08/22/2018] [Accepted: 10/03/2018] [Indexed: 10/28/2022]
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9
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Convertino VA. Mechanisms of inspiration that modulate cardiovascular control: the other side of breathing. J Appl Physiol (1985) 2019; 127:1187-1196. [PMID: 31225967 DOI: 10.1152/japplphysiol.00050.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The objective of this minireview is to describe the physiology and potential clinical benefits derived from inspiration. Recent animal and clinical studies demonstrate that one of the body's natural mechanisms associated with inspiration is to harness the respiratory pump to enhance circulation to vital organs. There is evidence that large reductions in intrathoracic pressure (>20 cmH2O) caused by some inspiration maneuvers (e.g., Mueller maneuver) or pathophysiology (e.g., heart failure, chronic obstructive lung disease) can result in adverse hemodynamic effects. However, the respiratory pump can improve cardiovascular functions when a "sweet spot" for generation of negative intrathoracic pressure during inspiration can be maintained at or less than 10 cmH2O below normal inspiration. These beneficial physiological effects include greater cardiac filling and output, lower intracranial pressure, cardiac baroreflex resetting, greater cerebral blood flow oscillatory patterns, increased vascular pressure gradients, and promoting sustained feedback between sympathetic nerve activity and arterial pressure. In addition to promoting gas exchange, data obtained from numerous animal and human experiments have provided new insights into "the other side of breathing": the modulation of circulation by reduced intrathoracic pressure generated during inspiration. The translation of these physiological relationships form the basis for the development and application of technologies designed to optimize the intrathoracic pump for treatment of clinical conditions associated with hypovolemia including cardiac arrest, orthostatic hypotension, hemorrhagic shock, and traumatic brain injury. Harnessing these fundamental mechanisms that control cardiopulmonary physiology provides opportunities to use inspiration as a potential tool to help treat significant and often life-threatening circulatory disorders.
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Affiliation(s)
- Victor A Convertino
- Battlefield Health & Trauma Center for Human Integrative Physiology, U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, Texas
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10
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Orozco BS, Engebretsen KM, Holger JS, Stellpflug SJ. A Swine Model of Severe Propranolol Toxicity Permitting Direct Measurement of Brain Tissue Oxygenation. J Med Toxicol 2019; 15:178-183. [PMID: 30895518 DOI: 10.1007/s13181-019-00707-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/06/2019] [Accepted: 03/06/2019] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION High-dose insulin (HDI) therapy has been used successfully for beta-blocker toxicity, but needs further study when hypotension persists despite HDI. The objective was to develop a model of propranolol toxicity with persistent hypotension despite HDI and to develop means to measure cerebral oxygen tension (PbrO2). METHODS Eight anesthetized Yorkshire pigs were instrumented with a tracheostomy, Swan-Ganz catheter, arterial catheter, and intra-cerebral pressure and oxygen monitor. Intravenous propranolol was given until the initial point of toxicity (POT); 25% reduction from baseline mean arterial pressure (MAP) × heart rate (HR). At the initial POT, normal saline (NS) bolus and infusion along with HDI infusion were started. The propranolol infusion was titrated up slowly to induce hypotension. Group 2 pigs received a norepinephrine (NE) infusion after a secondary POT defined as a MAP < 50 mmHg. NE was titrated to maintain subsequent MAPs > 50 mmHg. Cardiac output, HR, MAP, PbrO2, and intracranial pressure were then recorded every 5 min until death or 4 h. Systemic vascular resistance, potassium, and glucose were also measured. Surviving pigs were euthanized. RESULTS Two pigs received unique doses for protocol development. One pig developed a tachyarrhythmia prior to protocol, one failed to reach secondary POT, leaving 2 pigs in each group reaching secondary POT. The range of PbrO2 recordings for group 1 was 12.7-48.5 mmHg and 9.2-26.2 mmHg for group 2. CONCLUSION We report a pilot study swine model of propranolol toxicity with hypotension despite HDI, in which physiologic measures including PbrO2 are achieved. Our toxicity model can be used in the future, and the hemodynamic and brain monitoring model may prove important for subsequent research in various contexts.
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Affiliation(s)
| | - Kristin M Engebretsen
- Department of Emergency Medicine, Regions Hospital, 640 Jackson St., St. Paul, MN, 55101, USA
| | - Joel S Holger
- Department of Emergency Medicine, Regions Hospital, 640 Jackson St., St. Paul, MN, 55101, USA
| | - Samuel J Stellpflug
- Department of Emergency Medicine, Regions Hospital, 640 Jackson St., St. Paul, MN, 55101, USA.
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12
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Intrathoracic pressure regulation therapy applied to ventilated patients for treatment of compromised cerebral perfusion from brain injury. J Med Case Rep 2018; 12:178. [PMID: 29941027 PMCID: PMC6020193 DOI: 10.1186/s13256-018-1720-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 05/20/2018] [Indexed: 11/10/2022] Open
Abstract
Background Reducing intrathoracic pressure in the setting of compromised cerebral perfusion due to acute brain injury has been associated with reduced intracranial pressure and enhanced cerebral perfusion pressure and blood flow in animals. Noninvasive active intrathoracic pressure regulation lowers intrathoracic pressure, increases preload, reduces the volume of venous blood and cerebral spinal fluid in the skull, and enhances cerebral blood flow. We examined the feasibility of active intrathoracic pressure regulation therapy in patients with brain injury. We hypothesized that active intrathoracic pressure regulation therapy would be associated with lowered intracranial pressure and increased cerebral perfusion pressure in these patients. Methods At three institutions, active intrathoracic pressure regulation therapy (CirQlator™, ZOLL) was utilized for 2 consecutive hours in five mechanically ventilated patients with brain injury. A 30-minute interval was used to collect baseline data and determine persistence of effects after device use. End-tidal carbon dioxide was controlled by respiratory rate changes during device use. The intracranial pressure, mean arterial pressure, and cerebral perfusion pressure were recorded at 5-minute intervals throughout all three periods of the protocol. Results for each interval are reported as mean and standard deviation. Results Intracranial pressure was decreased in all five patients by an average of 21% during (15 ± 4 mmHg) compared to before active intrathoracic pressure regulation (19 ± 4) (p = 0.005). This effect on intracranial pressure (15 ± 6) was still present in four of the five patients 30 minutes after therapy was discontinued (p = 0.89). As a result, cerebral perfusion pressure was 16% higher during (81 ± 10) compared to before active intrathoracic pressure regulation (70 ± 14) (p = 0.04) and this effect remained present 30 minutes after therapy was discontinued. No adverse events were reported. Conclusions These data support the notion that active intrathoracic pressure regulation, in this limited evaluation, can successfully augment cerebral perfusion by lowering intracranial pressure and increasing mean arterial pressure in patients with mild brain injury. The measured effects were immediate on administration of the therapy and persisted to some degree after the therapy was terminated.
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13
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Metzger A, Mulligan J, Grudic G. Development of a Non-invasive Cerebrovascular Status Algorithm to Estimate Cerebral Perfusion Pressure and Intracranial Pressure in a Porcine Model of Focal Brain Injury. Mil Med 2018; 183:119-123. [PMID: 29635594 DOI: 10.1093/milmed/usx198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 01/16/2018] [Indexed: 11/14/2022] Open
Abstract
Background New tools for diagnosis, monitoring, and treatment of elevated intracranial pressure (ICP) or compromised cerebral perfusion pressure (CPP) are urgently needed to improve outcomes after brain injury. Previous success in applying advanced data analytics to build precision monitors based on large, noisy sensor datasets suggested applying the same approach to monitor cerebrovascular status. In these experiments, a new algorithm was developed to estimate ICP and CPP using the arterial pressure waveform. Methods Sixty-five porcine subjects were subjected to a focal brain injury to simulate a mass lesion with elevated ICP. The arterial pressure waveform and the measured ICP from these subjects during injury and treatment were then utilized to develop and calibrate an ICP and CPP estimation algorithm. These estimation algorithms were then subsequently evaluated on 14 new subjects. Results The root mean square difference between actual ICP and estimated ICP was 2.0961 mmHg. The root mean square difference between the actual CPP and the estimated CPP was 2.6828 mmHg. Conclusion A novel ICP or CPP monitor based on the arterial pressure signal produced a very close approximation to actual measured ICP and CPP and warrants further evaluation.
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Affiliation(s)
- Anja Metzger
- Department of Emergency Medicine, University of Minnesota, 717 Delaware Street SE, Suite 508, Minneapolis, MN 55455.,Zoll Minneapolis, 1905 Cty Rd C West, Roseville, MN 55113
| | - Jane Mulligan
- Flashback Technologies, 1215 Spruce Street, Suite 101, Boulder, CO 80302
| | - Greg Grudic
- Flashback Technologies, 1215 Spruce Street, Suite 101, Boulder, CO 80302
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Ladny JR, Smereka J, Rodríguez-Núñez A, Leung S, Ruetzler K, Szarpak L. Is there any alternative to standard chest compression techniques in infants? A randomized manikin trial of the new "2-thumb-fist" option. Medicine (Baltimore) 2018; 97:e9386. [PMID: 29384839 PMCID: PMC5805411 DOI: 10.1097/md.0000000000009386] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Pediatric cardiac arrest is a fatal emergent condition that is associated with high mortality, permanent neurological injury, and is a socioeconomic burden at both the individual and national levels. The aim of this study was to test in an infant manikin a new chest compression (CC) technique ("2 thumbs-fist" or nTTT) in comparison with standard 2-finger (TFT) and 2-thumb-encircling hands techniques (TTEHT). METHODS This was prospective, randomized, crossover manikin study. Sixty-three nurses who performed a randomized sequence of 2-minute continuous CC with the 3 techniques in random order. Simulated systolic (SBP), diastolic (DBP), mean arterial pressure (MAP), and pulse pressures (PP, SBP-DBP) in mm Hg were measured. RESULTS The nTTT resulted in a higher median SBP value (69 [IQR, 63-74] mm Hg) than TTEHT (41.5 [IQR, 39-42] mm Hg), (P < .001) and TFT (26.5 [IQR, 25.5-29] mm Hg), (P <.001). The simulated median value of DBP was 20 (IQR, 19-20) mm Hg with nTTT, 18 (IQR, 17-19) mm Hg with TTEHT and 23.5 (IQR, 22-25.5) mm Hg with TFT. DBP was significantly higher with TFT than with TTEHT (P <.001), as well as with TTEHT than nTTT (P <.001). Median values of simulated MAP were 37 (IQR, 34.5-38) mm Hg with nTTT, 26 (IQR, 25-26) mm Hg with TTEHT and 24.5 (IQR,23.5-26.5) mm Hg with TFT. A statistically significant difference was noticed between nTTT and TFT (P <.001), nTTT and TTEHT (P <.001), and between TTEHT and TFT (P <.001). Sixty-one subjects (96.8%) preferred the nTTT over the 2 standard methods. CONCLUSIONS The new nTTT technique achieved higher SBP and MAP compared to the standard CC techniques in our infant manikin model. nTTT appears to be a suitable alternative or complementary to the TFT and TTEHT.
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Affiliation(s)
- Jerzy R. Ladny
- Department of Emergency Medicine and Disaster, Medical University Bialystok, Bialystok
| | - Jacek Smereka
- Department of Emergency Medical Service, Wroclaw Medical University, Wroclaw, Poland
| | - Antonio Rodríguez-Núñez
- Clinursid Research Group, School of Nursing, University of Santiago de Compostela
- Institute of Research of Santiago (IDIS)
- Pediatric Emergency and Critical Care Division, Hospital Clínico Universitario de Santiago de Compostela, SERGAS, Santiago de Compostela
- SAMID-II Network, Madrid, Spain
| | - Steve Leung
- Department of General Anesthesiology, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Kurt Ruetzler
- Department of General Anesthesiology, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Lukasz Szarpak
- Department of Emergency Medicine, Medical University of Warsaw, Warsaw, Poland
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Intrathoracic Pressure Regulation Improves Cerebral Perfusion and Cerebral Blood Flow in a Porcine Model of Brain Injury: Erratum. Shock 2017; 48:692. [PMID: 29140888 DOI: 10.1097/shk.0000000000000985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tiba MH, McCracken BM, Ansari S, Belle A, Cummings BC, Rajajee V, Patil PG, Alam HB, Ward KR. Novel Noninvasive Method of Cerebrovascular Blood Volume Assessment Using Brain Bioimpedance. J Neurotrauma 2017; 34:3089-3096. [DOI: 10.1089/neu.2017.5090] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Mohamad H. Tiba
- Department of Emergency Medicine, University of Michigan, Ann Arbor, Michigan
- Department of Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, Michigan
| | - Brendan M. McCracken
- Department of Emergency Medicine, University of Michigan, Ann Arbor, Michigan
- Department of Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, Michigan
| | - Sardar Ansari
- Department of Emergency Medicine, University of Michigan, Ann Arbor, Michigan
- Department of Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, Michigan
| | - Ashwin Belle
- Department of Emergency Medicine, University of Michigan, Ann Arbor, Michigan
- Department of Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, Michigan
| | - Brandon C. Cummings
- Department of Emergency Medicine, University of Michigan, Ann Arbor, Michigan
- Department of Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, Michigan
| | - Venkatakrishna Rajajee
- Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan
- Department of Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, Michigan
| | - Parag G. Patil
- Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan
- Department of Neurology, University of Michigan, Ann Arbor, Michigan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan
- Department of Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, Michigan
| | - Hasan B. Alam
- Department of Surgery, University of Michigan, Ann Arbor, Michigan
- Department of Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, Michigan
| | - Kevin R. Ward
- Department of Emergency Medicine, University of Michigan, Ann Arbor, Michigan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan
- Department of Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, Michigan
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Affiliation(s)
- Matthias L Riess
- Department of Anesthesiology, Vanderbilt University, 1161 21st Avenue South, T4202 MCN, Nashville, TN 37232-2520, USA.,Department of Pharmacology, Vanderbilt University, 2220 Pierce Avenue, Nashville, TN 37232, USA.,Department of Anesthesiology, TVHS VA Medical Center, 1310 24th Avenue South, Nashville, TN 37212, USA
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What's New in Shock Military Supplement 2015? Shock 2015; 44 Suppl 1:1-2. [PMID: 26177015 DOI: 10.1097/shk.0000000000000422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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