Min Of Compression Research Articles

Sustained Compression with a Pneumatic Cuff on Skeletal Muscles Promotes Muscle Blood Flow and Relieves Muscle Stiffness.

(1) Purpose: This study aimed to examine whether a pneumatic cuff could promote muscle blood flow and improve muscle stiffness by continuously compressing muscles with air pressure in healthy college students. (2) Method: Twenty-one healthy collegiate students participated in this study. The probe of the near-infrared spectrometer was attached to the upper surface of the left gastrocnemius muscle, and a cuff was wrapped around the left lower leg. The cuff was inflated to 200 mmHg. After 10 min, the cuff was deflated, and the patient rested for 10 min. Muscle stiffness and fatigue were assessed before and after the intervention. (3) Results: During 10 min of continuous compression, StO2 continued to decrease until seven min of compression. After 10 min of continuous compression, StO2 was 30.8 ± 10.4%, which was approximately half of 69.2 ± 6.1% at rest. After the release of the pneumatic cuff compression, the StO2 remained higher than that at rest from 1 to 10 min. Muscle hardness was 19.0 ± 8.0 before intervention was 8.7 ± 4.8 after the intervention. Muscle fatigue was 6.6 ± 1.7 cm before the intervention and 4.0 ± 1.6 cm after the intervention. (4) Conclusions: This study suggests that sustained muscle compression using a pneumatic cuff can promote muscle blood flow and improve muscle stiffness and fatigue.

Self-Propelled Dressings Containing Thrombin and Tranexamic Acid Improve Short-Term Survival in a Swine Model of Lethal Junctional Hemorrhage.

Hemorrhage is the leading cause of preventable death in trauma, and hemorrhage from noncompressible junctional anatomic sites is particularly difficult to control. The current standard is QuikClot Combat Gauze packing, which requires 3 min of compression. We have created a novel dressing with calcium carbonate microparticles that can disperse and self-propel upstream against flowing blood. We loaded these microparticles with thrombin and tranexamic acid and tested their efficacy in a swine arterial bleeding model without wound compression. Anesthetized immature female swine received 5 mm femoral arteriotomies to induce severe junctional hemorrhage. Wounds were packed with kaolin-based QuikClot Combat Gauze (KG), propelled thrombin-microparticles with protonated tranexamic acid (PTG), or a non-propelling formulation of the same thrombin-microparticles with non-protonated tranexamic acid (NPTG). Wounds were not compressed after packing. Each animal then received one 15 mL/kg bolus of hydroxyethyl starch solution followed by Lactated Ringer as needed for hypotension (maximum: 100 mL/kg) for up to 3 h. Survival was improved with PTG (3-h survival: 8/8, 100%) compared with KG (3/8, 37.5%) and NPTG (2/8, 25%) (P <0.01). PTG animals maintained lower serum lactate and higher hemoglobin concentrations than NPTG (P <0.05) suggesting PTG decreased severity of subsequent hemorrhagic shock. However, total blood loss, Lactated Ringer infusion volumes, and mean arterial pressures of surviving animals were not different between groups (P >0.05). Thus, in this swine model of junctional arterial hemorrhage, gauze with self-propelled, prothrombotic microparticles improved survival and 2 indicators of hemorrhagic shock when applied without compression, suggesting this capability may enable better treatment of non-compressible junctional wounds.

Thermal and Mechanical Properties of Ultra High Molecular Weight Polyethylene Fiber Reinforced High-Density Polyethylene Homocomposites: Effect of Processing Condition and Nanoclay Addition

A new method to prepare single-polymer high-density (HDPE)-ultra high molecular weight polyethylene (UHMWPE) fiber (PE-PE homocomposites) composed and also PE-PE homocomposites containing HDPE organo montmorillonite clay (OMMT) nanocomposites as a matrix (PE nanohomocomposites) was used. Owing to the major importance of fiber impregnation by the matrix and its effect on the adhesion of matrix/fiber and, consequently, the mechanical properties of the composite, a combination of powder impregnation and film stacking methods, utilizing compression molding, were used for manufacturing the PE-PE homocomposites and PE nanohomocomposites. In addition, PE nanohomocomposites with the matrix containing different amounts of nanoclay were prepared to investigate the effect of the clay on the interfacial and mechanical properties of the PE-PE nanohomocomposites. Several different processing conditions were examined to determine the best conditions for manufacturing of the PE-PE homocomposite and PE nanohomocomposites and it was concluded that 40 bar and 10 min of compression molding resulted in the highest overall mechanical properties. The PE-PE homocomposites and PE-PE nanohomocomposites showed identical trends for the relationship between the effects of processing conditions and mechanical properties. Mechanical results demonstrated that clay platelets could increase the interfacial strength by improving physical entanglements between fiber and matrix through better cocrystallization.

COMPARISON OF AMIODARONE AND LIDOCAINE IN A PROLONGED VENTRICULAR FIBRILLATION CANINE MODEL

ObjectivesThe purpose of this randomised, experimental canine study was to compare the effect of amiodarone and lidocaine on CPR when given simultaneously with adrenaline in a canine model of prolonged...

COMPARISON OF AMIODARONE AND LIDOCAINE IN A PROLONGED VENTRICULAR FIBRILLATION CANINE MODEL

COMPARISON OF AMIODARONE AND LIDOCAINE IN A PROLONGED VENTRICULAR FIBRILLATION CANINE MODEL

First results of radiotherapy after hyperbaric oxygenation with temozolomide for high-grade gliomas.

2048 Background: The outcome of patients with high-grade gliomas remains poor despite modern therapeutic arsenal. The objective of this study was to assess the feasibility and efficacy of radiotherapy (RT) given immediately after hyperbaric oxygenation (HBO) with Stupp protocol. Methods: All patients with histologically confirmed high-grade gliomas from 2008 till 2011 coveraged at GHSR hospital were enrolled. Patients underwent Stupp protocol consisting in 60 Gy RT with a daily dose of 2 Gy for 5 days per week administrated immediately after HBO. Temozolomide (TMZ) was administrated at the daily dose 75 mg/m², 7 days per week followed by 6 cycles of TMZ 150 to 200 mg/m² for 5 days each 28 day-cycle. HBO schedule was approximately 15 min of compression with air, 60 min of 100% oxygen inhalation and 10 min of decompression with oxygen. Results: A total of 21 patients were diagnosed and histologically confirmed high grade gliomas. Five were excluded because of HBO contraindications. Twelve patients (75%) had undergone debulking surgery. The time interval from completion of decompression to start of irradiation was less than 15 minutes (mean 14.25, range 8-18). Twelve patients (75%) received the complete dose of RT and TMZ. HBO was completed for 7 (43.75%). Five (31.25%) were temporarily stopped and 4 (25%) were definitively stopped. One patient (6.25%) suffered from pancytopenia with grade 4 thrombopenia and grade 3 neutropenia. The median follow up was 46.95 weeks (range 5.7-108.3). Nine patients (56.25%) are still alive. Four (25%) have a survival more than 16 months. Conclusions: HBO with Stupp protocol is feasible and promising but requiring a large multicentric study.

The 3:1 is superior to a 15:2 ratio in a newborn manikin model in terms of quality of chest compressions and number of ventilations

BackgroundMost cases of delivery room cardiopulmonary arrest result from an asphyxial process. Experimental evidence supports an important role for ventilation during asphyxial arrest. The optimal compression: ventilation (CV) ratio remains...

Can verbal guidance improve chest compression depth by nurses?

CPR chest compressions are often suboptimal. CPR coaching, such as guiding rate with a metronome, can correct compression and ventilation rates. Measurement and feedback of compressions moderately improve depth but add cost and complexity. We evaluated the effectiveness of a simple vocal prompt on compression depth.Methods: We randomized critical care nurses to perform CPR on an intubated manikin with an AED either with metronome guidance alone (control), or with metronome plus the prompt, “Remember to push hard” at the beginning of each minute (intervention). Each nurse did compressions for a 4-min period, followed by a 2-min rest, and 2 more minutes of compressions.Results: The participants did not differ in mean weight, height, total number of compressions (595 ± 37 vs. 616 ± 46, mean ± standard deviation), or compression rate (99 ± 6 min−1 vs. 103 ± 8 min−1) for control (n = 29) and intervention (n = 19) groups. Compression depth over all 6 min of compressions was 31 ± 9 mm control vs. 33 ± 10 mm intervention. Depth improved most following the 1-min prompt, when the 3-s mean depth increased from 33.8 ± 9.2 mm to 36.6 ± 9.5 mm after the prompt (n = 19, p < 0.005, paired t-test). The number of participants performing any compressions with excessive depth or incomplete release was not different between groups. Overall, 42 of 48 subjects found the metronome useful; 15 of 19 thought “Remember to push hard” was useful.Tabled 1MinuteControlInterventionDelta (mm)95%CI (mm)%diff135.2 ± 8.136.2 ± 9.41.0[−4.1,6.2]3.0%231.8 ± 8.134.4 ± 9.32.7[−2.5,7.8]8.4%329.6 ± 9.432.6 ± 9.23.0[−2.5,8.6]10.3%428.4 ± 9.330.9 ± 10.02.5[−3.2,8.2]8.8%Pause732.6 ± 8.634.6 ± 9.92.0[−3.4,7.4]6.1%829.4 ± 9.330.4 ± 9.41.0[−4.5,6.5]3.4% Open table in a new tab CPR chest compressions are often suboptimal. CPR coaching, such as guiding rate with a metronome, can correct compression and ventilation rates. Measurement and feedback of compressions moderately improve depth but add cost and complexity. We evaluated the effectiveness of a simple vocal prompt on compression depth. Methods: We randomized critical care nurses to perform CPR on an intubated manikin with an AED either with metronome guidance alone (control), or with metronome plus the prompt, “Remember to push hard” at the beginning of each minute (intervention). Each nurse did compressions for a 4-min period, followed by a 2-min rest, and 2 more minutes of compressions. Results: The participants did not differ in mean weight, height, total number of compressions (595 ± 37 vs. 616 ± 46, mean ± standard deviation), or compression rate (99 ± 6 min−1 vs. 103 ± 8 min−1) for control (n = 29) and intervention (n = 19) groups. Compression depth over all 6 min of compressions was 31 ± 9 mm control vs. 33 ± 10 mm intervention. Depth improved most following the 1-min prompt, when the 3-s mean depth increased from 33.8 ± 9.2 mm to 36.6 ± 9.5 mm after the prompt (n = 19, p < 0.005, paired t-test). The number of participants performing any compressions with excessive depth or incomplete release was not different between groups. Overall, 42 of 48 subjects found the metronome useful; 15 of 19 thought “Remember to push hard” was useful.

Does prearrest adrenergic integrity affect pressor response? A comparison of epinephrine and vasopressin in a spontaneous ventricular fibrillation swine model

Objectives Coronary perfusion pressure (CPP) during resuscitation from cardiac arrest has been shown to correlate with return of spontaneous circulation. Adrenergic blockade of beta-1 and alpha-1 receptors is common in the long-term management of ischemic heart disease and congestive heart failure. We sought to compare the CPP response to vasopressin vs. epinephrine in a swine model of cardiac arrest following pre-arrest adrenergic blockade. Methods Eight anesthetized and instrumented swine were administered 0.1 mg epinephrine and arterial pressure and heart rate response were measured. An infusion of labetalol was then initiated and animals periodically challenged with epinephrine until adrenergic blockade was confirmed. The left anterior descending coronary artery was occluded to produce ventricular fibrillation (VF). After 7 min of untreated VF, mechanical chest compressions were initiated. After 1 min of compressions, 1 mg epinephrine was given while CPP was recorded. When CPP values had returned to pre-epinephrine levels, 40 U of bolus vasopressin was given. Differences in CPP (post-vasopressor–pre-vasopressor) were compared within animals for the epinephrine and vasopressin response and with eight, non-adrenergically blocked, historical controls using Bayesian statistics with a non-informative prior. Results The CPP response following epinephrine was 15.1 mmHg lower in adrenergically blocked animals compared to non-adrenergically blocked animals (95% Highest Posterior Density [HPD] 2.9–27.2 mmHg lower). CPP went up 18.4 mmHg more following vasopressin when compared to epinephrine (95% HPD 8.2–29.1 mmHg). The posterior probability of a higher CPP response from vasopressin (vs. epinephrine) in these animals was 0.999. Conclusions Pre-arrest adrenergic blockade blunts the CPP response to epinephrine. Superior augmentation of CPP is attained with vasopressin under these conditions.

The two-thumb is superior to the two-finger method for administering chest compressions in a manikin model of neonatal resuscitation

BackgroundCurrent neonatal guidelines endorse both the two-thumb and the two-finger techniques for performing chest compressions. It remains unclear whether one method is superior to the other in achieving consistent depth.ObjectiveTo...

Spinal cord injury in rats: inability of nimodipine or anti-neutrophil serum to improve spinal cord blood flow or neurologic status.

The role of a calcium-mediated increase in vascular resistance and of vascular damage caused by polymorphonuclear leukocytes (PMNLs) in the development of neurologic deficit and disturbance of spinal cord circulation following spinal cord compression was studied in the rat. Spinal cord injury was induced by 5 min of compression with a load of 35 g on a 2.2 X 5.0 mm compression plate. This caused transient paraparesis. The rats received either the calcium receptor antagonist nimodipine or an anti-rat neutrophil serum (ANS). Nimodipine was infused i.v. for 4 h in an amount of 1.5 micrograms/kg/min starting 60 min after trauma. The number of circulating PMNLs was depleted by intraperitoneal injection of an ANS raised in sheep given 12 h before trauma. This caused a reduction to about 2% of the pre-ANS value. Controls received saline or normal sheep serum. The motor performance was assessed daily on the inclined plane. On day one, the day after injury, the capacity angle had decreased from about 63 degrees preoperatively to close to 32 degrees in the experimental groups. There was then a slow improvement in both the control and experimental groups and on day 4 the capacity angle was close to 43 degrees in all 3 groups. Spinal cord blood flow, as measured with the 14C-iodoantipyrine autoradiography method, was similar in all groups on day 4. As neither the neurologic dysfunction nor the spinal cord blood flow was affected by post-trauma treatment with nimodipine or pretreatment with ANS, the possibility that calcium-mediated vasoconstriction or PMNLs play a role in the development of posttraumatic neurologic disability was not supported by this study.

Opposing effects of anesthetics on pressure tolerance and compression rate effect.

Inert gas narcotics increase intrinsic pressure tolerance (1,000Pc) in CD-1 mice but interfere with development of the protective responses raising seizure thresholds during slower compression (e.g., 60Pc). This secondary narcotic effect can block up to 40% of the total attainable increase in Pc. The narcosis susceptible moiety of this compression rate effect develops early, whereas a narcosis resistant remnant accounts for increase in Pc occurring after 90 min of compression or pressure exposure. Pressure conditioning by multiday pressure exposure entails increases in both 60Pc and 1,000Pc and in virtual annullment of the compression rate effect. The effect can be completely blocked by narcotic gases in the conditioning atmosphere. In addition to blocking part of the compression rate effect the presence of narcotic gases under these conditions can reverse the effects of previously established pressure conditioning. 60Pc regresses much more slowly under these conditions than 1,000Pc. Either reversal rate is much more rapid in air at 1 ATA than at 80 ATA under 0.9 atm N2O. The implications of these data are discussed with regard to evaluation of the hypothesis of antagonism between inert gas narcotics and high pressures and to elaboration of the monoamine hypothesis to account for the modification of the compression rate effect by narcotic gases.