Abstract 143: The Modified Shock Index Separates Survivors from Non-Survivors in a Swine Model of Hemorrhagic Shock and Traumatic Brain Injury

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_4) ◽  
Author(s):  
Jenna Mendelson ◽  
Matt Maggio ◽  
Salvatore Aiello ◽  
Jeejabai Radhakrishnan ◽  
Alvin Baetiong ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Heart Rate ◽  
Brain Injury ◽  
Mean Arterial Pressure ◽  
Cardiac Index ◽  
Arterial Pressure ◽  
Hemorrhagic Shock ◽  
Swine Model ◽  
Risk Of Death ◽  
Arterial Blood

The ratio between heart rate and arterial blood pressure during hemorrhagic shock has been shown useful to identify individuals at risk of death. We herein compared the index using the systolic arterial pressure (SI) and using the mean arterial pressure (MSI) along with other measurements including cardiac index and lactate in a swine model of hemorrhagic shock and traumatic brain injury developed to model injury in the battlefield. The parent study was designed to compare three different types of vasopressin agonists with control solution while practicing fluid-restricted resuscitation. The present analysis included 60 experiments focused on the initial 240 minutes with induction of hemorrhagic shock by liver laceration removing approximately 1,000 ml of blood in 30 minutes. Eight animals died during the acute phase and compare to 52 survivors, they had higher (median, IQR) MSI (4.6; 3.3 - 5.4 vs 2.5; 2.0 - 3.1; p < 0.001), SI (2.7; 2.1 - 3.1 vs 1.8; 1.6 - 2.2; p < 0.001), lower cardiac index (2.8; 2.3 - 3.4 vs 3.7; 3.2 - 4.2; p < 0.001), but no differences in lactate levels. Three of the eight non-survivors (37.5%) and 42 of the 52 survivors (80.1%) received a vasopressin analog (p = 0.019). Compared to other measurements of hemodynamic stability, monitoring the ratio between the heart rate and mean arterial pressure is a feasible and practical approach to deploy in various out of hospital settings including the battlefield as well as in civilian trauma. This approach could also guide interventions including the use of vasopressor agents, which our studies demonstrate having a survival effect during acute bleeding caused by hemorrhagic shock.

Abstract WP276: Drag Reducing Polymers Based Resuscitation Fluid Improves Cerebral Microcirculation After Mild Traumatic Brain Injury and Hemorrhagic Shock

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Devon Lara ◽  
Gloria Statom ◽  
Olga A Bragina ◽  
Marina V Kameneva ◽  
Edwin M Nemoto ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Arterial Pressure ◽  
Hemorrhagic Shock ◽  
Hospital Care ◽  
Microvascular Perfusion ◽  
Arterial Hypotension ◽  
Cerebral Microcirculation ◽  
Neuronal Necrosis ◽  
Resuscitation Fluid

Introduction: Hemorrhagic shock (HS), causing arterial hypotension, often occurs after traumatic brain injury (TBI). Current resuscitation fluids do not ameliorate the impaired cerebral microvascular perfusion leading to hypoxia, neuronal death, increased mortality and poor neurological outcome. Nanomolar concentrations of intravascular blood soluble drag reducing polymers (DRP) were shown to increase tissue perfusion and oxygenation and decrease peripheral vascular resistance by rheological modulation of hemodynamics. We hypothesized that the resuscitation fluid with DRP would improve cerebral microcirculation, oxygenation and neuronal recovery after TBI combined with HS (TBI+HS). Methods: Mild TBI was induced in rats by fluid percussion pulse (1.5 ATA, 50 ms duration) followed by induced by phlebotomy arterial hypotension (40 mmHg). Resuscitation fluid (lactated Ringers, LR) with DRP (DRP/LR) or without (LR) was infused to restore mean arterial pressure (MAP) to 60 mmHg for one hour (pre-hospital care), followed by re-infusion of blood to a MAP of 100 mmHg (hospital care). Using in vivo 2-photon laser scanning microscopy over the parietal cortex we monitored changes in microvascular blood flow, tissue oxygenation (NADH) and neuronal necrosis (i.v. propidium Iodide) for 5 hr after TBI+HS. Doppler cortical flow, rectal and cranial temperatures, arterial pressure, blood gases and electrolytes were monitored. Results: TBI+HS compromised brain microvascular flow leading to tissue hypoxia followed by neuronal necrosis. Resuscitation with DRP/LR compared to LR better improved cerebral microvascular perfusion (82 ± 9.7% vs. 62 ± 9.7%, respectively from pre-TBI baseline, p<0.05, n=7), attenuated capillary microtrombi formation and re-recruited collapsed during HS capillaries. Improved microvascular perfusion increased cortical oxygenation reducing hypoxia (77 ± 8.2% vs. 60 ± 10.5%, by DRP-LR vs. LR, respectively from baseline, p<0.05) and decreased neuronal necrosis (21 ± 7.2% vs. 36 ± 7.3%, respectively as a percentage of total neurons, p<0.05). Conclusions: DRP/LR resuscitation fluid is superior in the restoration of the cerebral microcirculation and neuroprotection following TBI + HS compared to volume expansion with LR.

scholarly journals Acute Cardiovascular Effects of Epidural Spinal Cord Stimulation

2007 ◽  
Vol 5;10 (9;5) ◽  
pp. 677-685
Author(s):  
David M. Schultz
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Spinal Cord Stimulation ◽  
Statistical Significance ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Arterial Blood

Background: Several animal studies support the contention that thoracic spinal cord stimulation (SCS) might decrease arterial blood pressure. Objective: To determine if electrical stimulation of the dorsal spinal cord in humans will lower mean arterial pressure (MAP) and heart rate (HR). Design: Case Series Methods: Ten normotensive subjects that were clinically indicated for SCS testing were studied. Two of the 10 patients who underwent testing were excluded from the analysis because they did not respond to the Cold Pressor Test (CPT). Systolic blood pressure, diastolic blood pressure, and heart rate were measured continuously at the wrist (using the Vasotrac device). SCS was administered with quadripolar leads implanted into the epidural space under fluoroscopic guidance. SCS was randomly performed either in the T1-T2 or T5-T6 region of the spinal cord during normal conditions as well as during transient stress induced by CPT. The CPT was conducted by immersing the non-dominant hand in ice-cold water for 2 minutes. Results: There were moderate decreases in MAP and HR during SCS at the T5-T6 region compared to baseline that did not reach statistical significance. However, SCS at the T1-T2 region tended to increase MAP and HR compared to baseline but the change did not reach statistical significance. Arterial blood pressure was transiently elevated by 9.4 ± 3.8 mmHg using CPT during the control period with SCS turned off and also during SCS at either the T1-T2 region or T5-T6 region of the spinal cord (by 9.2 ± 5 mmHg and 10.7 ± 8.4 mmHg, respectively). During SCS at T5-T6, the CPT significantly increased MAP by 5.9±7.1 mmHg compared to control CPT (SCS off). Conclusion: This study demonstrated that SCS at either the T1-T2 or T5-T6 region did not significantly alter MAP or HR compared to baseline (no SCS). However, during transcient stress (elevated sympathetic tone) induced by CPT, there was a significant increase in MAP and moderate decrease in HR during SCS at T5-T6 region, which is not consistent with previous data in the literature. Acute SCS did not result in adverse cardiovascular responses and proved to be safe. Key words: Spinal cord stimulation, mean arterial pressure, heart rate, cold pressor test

Effects of ethanol on limited resuscitation in a model of traumatic brain injury and hemorrhagic shock

2006 ◽  
Vol 105 (6) ◽  
pp. 884-893 ◽  
Author(s):  
Brian J. Zink ◽  
Susan A. Stern ◽  
Brian D. McBeth ◽  
Xu Wang ◽  
Michelle Mertz
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Hemorrhagic Shock ◽  
Tap Water ◽  
Gastrostomy Tube ◽  
Survival Times ◽  
Ethanol Intoxication ◽  
Ethanol Group ◽  
Arterial Blood ◽  
Fluid Percussion Injury

Object Limited resuscitation following uncontrolled hemorrhagic shock (HS) has been associated with improved outcomes in various animal models, although it has not been previously studied in the setting of traumatic brain injury (TBI) and ethanol intoxication. The aim of the present study was to determine the effects of ethanol intoxication in a model of experimental TBI and HS treated with limited resuscitation. Methods After induction of anesthesia and the placement of instruments, swine were subjected to a fluid-percussion injury of 3 atm. Simultaneously, hemorrhage was induced from an arterial catheter via a computerized roller pump to a mean arterial blood pressure (MABP) of 50 mm Hg, at which time uncontrolled hemorrhage was induced by the creation of an aortic tear. When the MABP decreased to 30 mm Hg, limited resuscitation to a MABP of 60 mm Hg was begun. After 60 minutes, animals were aggressively resuscitated to baseline MABP levels. Two groups of animals were studied: those receiving tap water by gastrostomy tube and those receiving ethanol (4 g/kg) by gastrostomy tube. Animals were monitored for 180 minutes after TBI. Hemorrhage volumes were significantly greater in ethanol-infused animals (mean ± standard deviation, 41 ± 34 mm Hg) compared with tap water–infused animals (17 ± 18 mm Hg; p = 0.048). Resuscitation requirements were significantly higher and metabolic parameters significantly worse in the ethanol group. Survival time was also significantly decreased in the animals infused with ethanol (81 ± 60 minutes) compared with those infused with tap water (130 ± 51 minutes; p = 0.035). Conclusions Ethanol intoxication led to increased hemorrhage volume and worsened hemodynamic and metabolic profiles in this model of limited resuscitation after TBI and HS. Ethanol-exposed animals had increased resuscitation requirements and decreased survival times.

Anesthetic effects on hemodynamics of spontaneously hypertensive and Wistar-Kyoto rats

1980 ◽  
Vol 238 (4) ◽  
pp. H539-H544 ◽  
Author(s):  
T. L. Smith ◽  
P. M. Hutchins
Keyword(s):  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Cardiac Index ◽  
Arterial Pressure ◽  
Peripheral Resistance ◽  
Central Hemodynamics ◽  
Spontaneously Hypertensive ◽  
Pentobarbital Sodium ◽  
Anesthetic Agents ◽  
Wistar Kyoto

We studied the effects of three anesthetic agents on the central hemodynamics of spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats instrumented with chronic electromagnetic flow probes and arterial pressure catheters. Cardiovascular alterations due to ether, pentobarbital sodium (PBS; 50 mg/kg), and a 2% chloralose-7.5% urethan mixture (CU; 6 ml/kg) were determined. Ether produced significant elevations in heart rate (HR), cardiac index (CI), stroke volume (SV), and peak aortic flow velocity (PAFV) in SHRs (P less than 0.01) and elevations of HR and CI in WKYs (P less than 0.05). Ether reduced total peripheral resistance (TPR) and mean arterial pressure (MAP) in WKYs and SHRs (P less than 0.01). PBS decreased HR, CI, SV, MAP, PAFV, and minute work (MW) in both WKYs and SHRs (P less than 0.05--P less than 0.001). PBS also lowered TPR in WKYs (P less than 0.05). CU produced effects similar to those of PBS, but did not alter HR or TPR. Central hemodynamics are therefore significantly altered by these anesthetics when compared to those of conscious rats. These agents also have differential effects on the hemodynamics of SHRs and WKYs.

Does Spinal Anesthesia Result in a More Complete Sympathetic Block Than That from Epidural Anesthesia?

1995 ◽  
Vol 82 (4) ◽  
pp. 877-883. ◽  
Author(s):  
Rom A. Stevens ◽  
David Beardsley ◽  
J. Lee White ◽  
Tzu-Cheg Kao ◽  
Rod Gantt ◽  
...  
Keyword(s):  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Cardiac Index ◽  
Arterial Pressure ◽  
Spinal Anesthesia ◽  
Epidural Anesthesia ◽  
Conduction Block ◽  
Plasma Catecholamine ◽  
Sympathetic Block ◽  
Plasma Catecholamine Concentrations

Background Spinal and epidural injection of local anesthetics are used to produce sympathetic block to diagnose and treat certain chronic pain syndromes. It is not clear whether either form of regional anesthesia produces a complete sympathetic block. Spinal anesthesia using tetracaine has been reported to produce a decrease in plasma catecholamine concentrations. This has not been demonstrated for epidural anesthesia in humans with level of anesthesia below C8. One possible explanation is that spinal anesthesia results in a more complete sympathetic block than epidural anesthesia. To examine this question, a cross-over study was performed in young, healthy volunteers. Methods Ten subjects underwent both spinal and epidural anesthesia with lidocaine (plain) on the same day with complete recovery between blocks. By random assignment, spinal anesthesia and epidural anesthesia were induced via lumbar injection. Before and 30 min after local anesthetic injection, a cold pressor test (CPT) was performed. Blood was obtained to determine epinephrine and norepinephrine plasma concentrations at four stages: (1) 20 min after placing peripheral catheters, (2) at the end of a 2-min CPT (before conduction block), (3) 30 min after injection of epidural or spinal lidocaine, and (4) at the end of a second CPT (during anesthesia). Mean arterial pressure, heart rate, noninvasive cardiac index, and analgesia to pin-prick were monitored. Results Neither spinal nor epidural anesthesia changed baseline resting values of catecholamines or any hemodynamic variable, except heart rate, which was slightly decreased during spinal anesthesia. Median level of analgesia was T4 during spinal and T3 during epidural anesthesia. CPT before conduction block reliably increased heart rate, mean arterial pressure, cardiac index, epinephrine, and norepinephrine. Conduction block attenuated the increase in response to CPT only in mean arterial pressure (spinal and epidural) and cardiac index (spinal only). Neither technique blocked the increase in heart rate, norepinephrine, or epinephrine to CPT. Conclusions Spinal anesthesia did not result in a more complete attenuation of the sympathetic response to a CPT than did epidural anesthesia. In response to the CPT, spinal anesthesia blocked the increase in cardiac index, and epidural anesthesia resulted in a decrease in total peripheral resistance compared to the pre-anesthesia state. The differences between the techniques are not significant and are of uncertain clinical implications.

scholarly journals Effect of twelve week training program in blood pressure and heart rate at rest in older hypertensive and normotensive women

2017 ◽  
Vol 1 (1) ◽  
pp. 51
Author(s):  
Teuta Osmani Vllasolli
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Training Program ◽  
Older Women ◽  
Experimental Period ◽  
Dynamic Resistance ◽  
Arterial Blood ◽  
Resistance Exercises

Introduction: Epidemiological studies suggest that non-pharmacological       interventions such as exercise may be beneficial for treatment of hypertension.  However the potential benefits of exercises especially resistance training on arterial blood pressure and resting heart rate in older adults without hypertension remain controversial. Objective: To analyze the effect of twelve weeks of training program on systolic blood pressure (SBP) diastolic blood pressure (DBP) mean arterial    pressure (MAP) and heart rate (HR) in older women with and without hypertension. Methods: Seventeen hypertensive women (HW) and 10 normotensive women (NW) were included in training program selected by pre-exercise evaluation of the     cardiovascular status and other risks factors (smoking dislipidemia and diabetes). Training program three times per week was consisted from10 minutes of stretching exercises; 45 minutes of aerobic endurance (gait) and 10 min with five minutes of   relaxation while two times per week were included dynamic resistance exercises  (involving the major muscle groups) The training sessions of resistance exercises were performed in three sets of 8 to 10 repetition of maximum (RM) with rest    interval between sets and exercises of 90 seconds. These days aerobic exercises last only 30minutes.Hemodynamic parameters at rest were evaluated by auscultatory method (mercury sphygmomanometer) and HR by Pulsioxymeter monitor (Polar) before and after twelve weeks of experimental period. Results: The HW group (age 66.8 آ± 5.4 years) and the NW (65.2 آ± 4.8years). In HW was found a reduction of SBP (-10.6mmHgp <0.01) and DBP (-1.94 p=0.043). Although significant reduction were observed in SBP (- 6.7mmHg p<0.05) of NW group there were no significant reduce in DBP after exercises (p=0.0 32). Mean arterial pressure (MAP) and resting HR also didn’t show important changes. Conclusion: Twelve weeks training program consisted of aerobic exercises and dynamic resistance exercises is shown to be an   effective training in reduction of resting SBP in older women with hypertension and also to promote adaptations in the cardiovascular system of normotensive older women without. Keywords: older women blood pressure hypertension normotension heart rate exercise.

Pressure autoregulation, intracranial pressure, and brain tissue oxygenation in children with severe traumatic brain injury

2009 ◽  
Vol 4 (5) ◽  
pp. 420-428 ◽  
Author(s):  
Anthony A. Figaji ◽  
Eugene Zwane ◽  
A. Graham Fieggen ◽  
Andrew C. Argent ◽  
Peter D. Le Roux ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Blood Flow ◽  
Brain Injury ◽  
Mean Arterial Pressure ◽  
Intracranial Pressure ◽  
Glasgow Coma Scale ◽  
Arterial Pressure ◽  
Clinical Factors ◽  
Severe Tbi ◽  
Pressure Autoregulation

Object Cerebral pressure autoregulation is an important neuroprotective mechanism that stabilizes cerebral blood flow when blood pressure (BP) changes. In this study the authors examined the association between autoregulation and clinical factors, BP, intracranial pressure (ICP), brain tissue oxygen tension (PbtO2), and outcome after pediatric severe traumatic brain injury (TBI). In particular we examined how the status of autoregulation influenced the effect of BP changes on ICP and PbtO2. Methods In this prospective observational study, 52 autoregulation tests were performed in 24 patients with severe TBI. The patients had a mean age of 6.3 ± 3.2 years, and a postresuscitation Glasgow Coma Scale score of 6 (range 3–8). All patients underwent continuous ICP and PbtO2 monitoring, and transcranial Doppler ultrasonography was used to examine the autoregulatory index (ARI) based on blood flow velocity of the middle cerebral artery after increasing mean arterial pressure by 20% of the baseline value. Impaired autoregulation was defined as an ARI < 0.4 and intact autoregulation as an ARI ≥ 0.4. The relationships between autoregulation (measured as both a continuous and dichotomous variable), outcome, and clinical and physiological variables were examined using multiple logistic regression analysis. Results Autoregulation was impaired (ARI < 0.4) in 29% of patients (7 patients). The initial Glasgow Coma Scale score was significantly associated with the ARI (p = 0.02, r = 0.32) but no other clinical factors were associated with autoregulation status. Baseline values at the time of testing for ICP, PbtO2, the ratio of PbtO2/PaO2, mean arterial pressure, and middle cerebral artery blood flow velocity were similar in the patients with impaired or intact autoregulation. There was an inverse relationship between ARI (continuous and dichotomous) with a change in ICP (continuous ARI, p = 0.005; dichotomous ARI, p = 0.02); that is, ICP increased with the BP increase when ARI was low (weak autoregulation). The ARI (continuous and dichotomous) was also inversely associated with a change in PbtO2 (continuous ARI, p = 0.002; dichotomous ARI, p = 0.02). The PbtO2 increased when BP was increased in most patients, even when the ARI was relatively high (stronger autoregulation), but the magnitude of this response was still associated with the ARI. There was no relationship between the ARI and outcome. Conclusions These data demonstrate the influence of the strength of autoregulation on the response of ICP and PbtO2 to BP changes and the variability of this response between individuals. The findings suggest that autoregulation testing may assist clinical decision-making in pediatric severe TBI and help better define optimal BP or cerebral perfusion pressure targets for individual patients.

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