Comparative characteristics of the main sanogenetic mechanisms in large laboratory animals (pigs) with acute blood loss and after infusion of an isotonic colloidal solution based on dextran and an isotonic solution based on polyglucin in conditions of general external cooling

Author(s):  
A.O. Shvetc ◽  
I.A. Shperling ◽  
A.V. Krupin ◽  
P.A. Romanov ◽  
N.N. Matveeva

The experiment was carried out on male pigs, which in the operating room were simulated with acute blood loss (air temperature 23oC). Then the animals were placed in a climatic chamber (minus 50 ° C) for 10 minutes. Then the temperature in the climatic chamber was raised to minus 10 ° C and the introduction of the test solutions to the animals began. It was found that in both groups there were similar indicators of blood pressure. The heart rate and respiratory rate in animals in the group with the experimental solution based on polyglucin derivatives were lower than in the group with the solution based on dextran. Key words: external general cooling, pigs, blood pressure, heart rate, respiratory rate, infusion solution.

Author(s):  
A. V. Krupin ◽  
I. A. Shperling ◽  
P. A. Romanov ◽  
M. I. Shperling

Relevance.High efficiency of hypertonic (hyperosmolar) solutions in acute blood loss is known. However, data on changes in the body, developing as a result of infusion of such drugs (including cooled) in the providing of care after acute blood loss is limited or absent. This fact complicates the development of tactics in their use, especially in emergency situations at low temperatures.Intention.To reveal features of functional and laboratory indicators In experiments on animals as a result of infusion of warm (+22 °С) or the cooled (–3 °С) hypertonic solution based on hydroxyethyl starch and sodium chloride (HyperHAES, further – HHES) at the acute blood loss of 50 % of blood volume (BV).Methodology.Animals (20 male sheep) with modeled blood loss were distributed into 2 experimental and 2 control groups of 5 animals each. Sheep in the 1st experimental group were placed in the heat chamber with temperature –7 °С for 15 min. Then they underwent the intravenous infusion of a cooled HHES at a dose of 4 ml/kg of weight through the jugular vein with a disposable syringe (volume 20 ml) evenly with a speed of 60 ml per minute. After that they were left in the heat chamber until the time of 1 hour in total. Individuals in the 2nd experimental group were injected with an equivalent volume of warm solution during the corresponding periods of the experiment at an external temperature of +22 °C. 1 hour after beginning of the infusion all animals were intravenously injected with colloidal solution based on hydroxyethyl starch (“Voluven”) at an external temperature of +22 °C. During 1 day the dynamics of rectal temperature, arterial pressure, heart rate and respiratory movements, osmolarity of blood plasma and content of osmotically active components, quantitative indicators of red blood were evaluated.Results.Animals at a temperature of +22 °C or at a temperature of –7 °C died in (82 ± 3) min and (70 ± 5) min (p < 0.05) respectively after the start of exfusion. Intravenous fluids (warm or cooled HHES) ensured the survival in 100 % of cases. As a result of blood loss, subsequent infusion of cooled HHES and following presence in the heat chamber, rectal temperature in sheep decreased by 4.9 °C (14.2%, p < 0.05) relative to the initial values. Two and 4 min after infusion of cooled or warm HHES systolic blood pressure increased by 24.9 % (p < 0.05) and 14.9 % (p < 0.05), respectively, and were restored to the normal level during the following 40 min. Infusion of “Voluven” contributed to the stabilization of blood pressure within 1 day after infusion of HHES. Blood loss led to increased heart rate by 2.1 times (p < 0.05), infusion of HHES slightly reduced the severity of tachycardia. Within 10 minutes after the introduction of cooled HHES, dynamics of heart rate was less stable. Infusion of warm or cooled HHES increased osmolarity of blood plasma by 9.5–9.9 % (p < 0.05), which was associated with an increase of sodium and glucose concentrations in blood. Infusion of “Voluven” reduced osmolarity of blood plasma, which became similar to initial values at the end of Day 1 after infusion of HHES. Blood loss, infusion of HHES and “Voluven” decreased quantitative indicators of red blood via removal of red blood cells from the bloodstream, as well as compensatory and post-transfusion hemodilution.Conclusion.The infusion of warm or cold hypertonic saline (HyperHAES) ensures the survival of experimental animals in post-hemorrhagic period. The positive effect of the drug is associated with compensatory haemodilution (including increased osmolarity of blood plasma), as well as with better functioning of the cardiovascular system. Specific cooled HHES effects include an earlier and pronounced rise in blood pressure. Considering changes in functional and laboratory parameters after infusion of warm or cooled HHES, a reliable system should be developed to remove casualties from emergency areas and to take earlier and complete diagnostic and treatment measures.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259559
Author(s):  
Ryan P. Sixtus ◽  
Cholawat Pacharinsak ◽  
Clint L. Gray ◽  
Mary J. Berry ◽  
Rebecca M. Dyson

Background Non-invasive physiological monitoring can induce stress in laboratory animals. Sedation reduces the level of restraint required, thereby improving the validity of physiological signals measured. However, sedatives may alter physiological equilibrium introducing unintended bias and/or, masking the experimental outcomes of interest. We aimed to investigate the cardiorespiratory effects of four short-acting sedatives in juvenile guinea pigs. Method 12 healthy, 38 (26–46) day-old Dunkin Hartley guinea pigs were included in this blinded, randomised, crossover design study. Animals were sedated by intramuscular injection using pre-established minimum effective doses of either alfaxalone (5 mg/kg), diazepam (5 mg/kg), ketamine (30 mg/kg), or midazolam (2 mg/kg) administered in random order with a minimum washout period of 48 hours between agents. Sedative depth, a composite score comprised of five assessment criteria, was observed every 5-min from dosing until arousal. Physiological monitoring of cardiorespiratory status included measures of heart rate, blood pressure, respiratory rate, and peripheral microvascular perfusion. Results Ketamine and alfaxalone were most effective in inducing stable sedation suitable for physiological monitoring, and diazepam less-so. Midazolam was unsuitable due to excessive hypersensitivity. All sedatives significantly increased heart rate above non-sedated control rates (P<0.0001), without altering blood pressure or microvascular perfusion. Alfaxalone and ketamine reduced respiratory rate relative to their control condition (P<0.0001, P = 0.05, respectively), but within normative ranges. Conclusion Ketamine and alfaxalone are the most effective sedatives for inducing short duration, stable sedation with minimal cardiorespiratory depression in guinea pigs, while diazepam is less-so. However, alfaxalone is the most appropriate sedative for longitudinal studies requiring multiple physiological timepoints.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 914.2-914
Author(s):  
S. Boussaid ◽  
M. Ben Majdouba ◽  
S. Jriri ◽  
M. Abbes ◽  
S. Jammali ◽  
...  

Background:Music therapy is based on ancient cross-cultural beliefs that music can have a “healing” effect on mind and body. Research determined that listening to music can increase comfort and relaxation, relieve pain, lower distress, reduce anxiety, improve positive emotions and mood, and decrease psychological symptoms. Music therapy has been used greatly in various medical procedures to reduce associated anxiety and pain. Patients have a high level of anxiety when they are in the hospital, this is the case of patients with rheumatic diseases who consult regularly to have intravenous infusion of biological therapies.Objectives:The purpose of this study was to examine the effectiveness of music therapy on pain, anxiety, and vital signs among patients with chronic inflammatory rheumatic diseases during intravenous infusion of biological drugs.Methods:Fifty patients were divided into two groups: The experimental group G1 (n=25) received drug infusion while lestening to soft music (30 minutes); and the control group G2 (n=25) received only drug infusion. Measures include pain, anxiety, vital signs (blood pressure, heart rate and respiratory rate). The pain was measured using visual analogic scale (VAS). The state-trait anxiety inventory (STAI) was used for measuring anxiety, low anxiety ranges from 20 to 39, the moderate anxiety ranges from 40 to 59, and high anxiety ranges from 60 to 80. Vital signs (systolic blood pressure [SBP], diastolic blood pressure [DBP], heart rate [HR], and respiratory rate [RR]) were measured before, during and immediately after the infusion.Statistical package for social sciences (SPSS) was used for analysis.Results:The mean age in G1 was 44.45 years (26-72) with a sex ratio (M/F) of 0.8. Including the 25 patients, 12 had rheumatoid arthritis, 10 had ankylosing spondylitis and 3 had psoriatic arthritis. The mean disease duration was 8 years. In G2, the mean age was 46 years (25-70) with a sex ratio (M/F) of 0.75, 12 had rheumatoid arthritis, 11 had ankylosing spondylitis and 2 had psoriatic arthritis. The mean disease duration was 7.5 years. The biological drugs used were: Infliximab in 30 cases, Tocilizumab in 12 cases and Rituximab in 8 cases.Before the infusion, the patients of experimental group had a mean VAS of 5/10±3, a mean STAI of 50.62±6.01, a mean SBP of 13.6 cmHg±1.4, a mean DBP of 8.6 cmHg±1, a mean HR of 85±10 and a mean RR of 18±3. While in control group the mean VAS was 5.5±2, the mean STAI was 50.89±5.5, the mean SBP was 13.4±1.2, the mean DBP was 8.8±1.1, the mean HR was 82±8 and the mean RR was 19±2.During the infusion and after music intervention in G1, the mean STAI became 38.35±5 in G1 versus 46.7±5.2 in G2 (p value=0.022), the mean SBP became 12.1±0.5 in G1 versus 13±1 in G2 (p=0.035), the mean DBP became 8.1±0.8 in G1 versus 8.4±0.9 in G2 (p=0.4), the mean HR became 76±9 in G1 versus 78±7 in G2 (p=0.04) and the mean RR became 17.3±2.1 in G1 versus 18.2±1.7 in G2 (p=0.39).This study found a statistically significant decrease in anxiety, systolic blood pressure and heart rate in patients receiving music interventions during biological therapies infusion, but no significant difference were identified in diastolic blood pressure and respiratory rate.Conclusion:The findings provide further evidence to support the use of music therapy to reduce anxiety, and lower systolic blood pressure and heart rate in patients with rheumatic disease during biological therapies infusion.References:[1] Lin, C., Hwang, S., Jiang, P., & Hsiung, N. (2019).Effect of Music Therapy on Pain After Orthopedic Surgery -A Systematic review and Meta-Analysis. Pain Practice.Disclosure of Interests:None declared


2006 ◽  
Vol 75 (1) ◽  
pp. 3-12 ◽  
Author(s):  
J. Mokrý ◽  
T. Remeňová ◽  
K. Javorka

The purpose of the study was to evaluate the changes of respiratory rate, systemic blood pressure and heart rate variability parameters (HRV) during orthostasis in anaesthetized rabbits. Furthermore, these changes were influenced by affecting the renin-angiotensin-aldosterone (RAA) system and autonomic nervous system (ANS) to study the mechanisms participating in activity of spectral frequency bands of HRV in rabbits. Ten adult rabbits (Chinchilla) were anaesthetized by ketamine and flunitrazepam. The systemic blood pressure, tidal volume and respiratory rate were measured. HRV was evaluated by microcomputer system VariaPulse TF3E. The R-R intervals were derived from the electrocardiogram signal from subcutaneous needle electrodes. The evaluation of HRV in very low (VLF; 0.01-0.05 Hz), low (LF; 0.05-0.15 Hz) and high frequency bands (HF; 0.15-2.0 Hz) was made and parameters of frequency and time analysis were calculated. The measurements were made in horizontal (supine) position, in orthostasis (the angle of 60 °) and again in supine position before and after enalapril (0.5 mg/kg b.w.), metipranolol (0.2 mg/kg b.w.), and after subsequent bilateral cervical vagotomy. The orthostasis in anaesthetized rabbits is accompanied by depression of respiratory rate reversed only by vagotomy. Furthermore, decrease of systemic blood pressure, unchanged heart rate and increased characteristics of heart rate variability were found, with predominant increase of spectral power in LF and VLF bands. This elevation can be eliminated only by complete blockade of ANS. Although the participation of ANS or RAA system in modification of individual HRV frequency bands is not as specific as in humans, we confirmed the participation of RAA system in determination of the VLF band.


Author(s):  
Hugo Farne ◽  
Edward Norris-Cervetto ◽  
James Warbrick-Smith

You should ask the nurse: • What the trend is in urine output—has it been gradually decreasing, or suddenly stopped? If the latter, have they checked if the urinary catheter is blocked by flushing it? This is a rapidly reversible cause of poor urinary output. • What the observations are for the patient. Ask for the heart rate, blood pressure, respiratory rate, oxygen saturations, and temperature, so you can get an idea of how unwell the patient is. This will help you prioritize how soon you need to see the patient. Healthy adults have a urine output of about 1 mL/kg/hour. Oliguria refers to a reduced urine output and is defined variously as <400 mL/day, <0.5 mL/kg/hour, or <30 mL/hour. Anuria refers to the complete absence of urine output. Decreased urine output should be taken very seriously as it may be the first (and only) sign of impending acute renal failure. Untreated, patients may die from hyperkalaemia, profound acidosis, or pulmonary oedema due to the kidneys not performing their usual physiological role. Normal urine output requires: • adequate blood supply to the kidneys • functioning kidneys, and • flow of urine from the kidneys, down the ureters, into the bladder, and out via the urethra. Pathology affecting any of these requirements can result in poor urine output, which is why the differential diagnosis for poor urinary output is often classified as shown in Figure 22.1. In practice, as a junior doctor you want to diagnose and treat the prerenal and postrenal causes. If you come to the conclusion that it is a renal cause (by exclusion), call the renal physicians for an expert opinion. This is crucial in determining the diagnosis: • Adequate intake? Remember that an adult of average size will require about 3 L of fluid intake per 24 hours (30–50 mL/kg/day). Febrile patients will require an extra 500 mL for every 1 °C above 37.0 °C to compensate for increased loss of fluids from evaporation and increased respiratory rate.


1989 ◽  
Vol 17 (3) ◽  
pp. 312-319 ◽  
Author(s):  
A. F. Van Leeuwen ◽  
R. G. Evans ◽  
J. Ludbrook

Information has come forward recently from several sources which provides new insights into the mechanisms that underlie the haemodynamic responses to acute blood loss. In unanaesthetised animals and human volunteers there are two distinct phases to these responses. At first, the engagement of baroreflexes results in a progressive rise in sympathetic vasoconstrictor drive and peripheral resistance, and the maintenance of arterial blood pressure at a near-normal level. When about one-third of blood volume has been lost, reflex sympathetic drive is switched off, and peripheral resistance and blood pressure fall abruptly to low levels despite a burst of vasopressin release. Research in conscious animals has now shown that the onset of this decompensatory phase is triggered by a signal from the heart, which activates an endogenous opioid mechanism in the brain. Activation of this mechanism can be prevented by administering a selective δ-receptor antagonist, or selective μ-receptor agonists (including alfentanil). It has not yet been established that this endogenous opioid mechanism is responsible for the decompensatory phase of acute blood loss in man, nor that it can be prevented or reversed by selective opioid agonists or antagonists.


1955 ◽  
Vol 33 (3) ◽  
pp. 436-447 ◽  
Author(s):  
H. G. Downie ◽  
J. A. F. Stevenson

Although the blood pressure is one of the important criteria in the standardization of hemorrhagic shock in the dog, it has rarely been used for this purpose in the rat. A method resembling the reservoir technique developed by Wiggers and Werle (1942) for the dog using blood pressure as the criterion has been modified for use with the rat. Male Sprague-Dawley rats weighing approximately 400 gm. were used. In the standardization of this technique the blood pressure was reduced to 30 mm. Hg in a 10-min. period of hemorrhage and then maintained at this level by subsequent small hemorrhages into the reservoir until reinfusion indicated the beginning of vascular collapse, at which time all the blood in the reservoir was returned. Considering that those animals which lived longer than 48 hr. were survivors, in a series of 27 animals, 21 died and 6 survived—a mortality rate of 78%.During the hypotensive period there was a consistent and steady drop in the respiratory rate and rectal temperature. The heart rate declined initially and tended to recover as the hypotensive period progressed. After reinfusion the blood pressure rose but. did not reach prehemorrhage levels. Hemorrhage into the bowel and convulsions were significant postreinfusion findings.


Author(s):  
Matt Wise ◽  
Paul Frost

Critical illness can be considered to be any disease process which causes physiological instability that leads to disability or death within minutes or hours. Fortunately, physiological instability associated with critical illness is easily detected by perturbations of simple clinical observations such as blood pressure, heart rate, respiratory rate, oxygen saturations, level of consciousness, and urine output. Individual abnormalities in these observations are sensitive for the presence of critical illness but non-specific. Specificity for critical illness improves as the number of abnormal clinical observations increases. Over recent years, a greater appreciation of the importance of deviations in simple clinical observations as a method of detecting critical illness has led to the development of a number of ‘early warning’ or ‘track and trigger’ systems. These systems attribute a score according to the magnitude and number of abnormal observations that are present, and a high score prompts immediate medical review. Although intuitively sensible, the evidence that these systems are effective in ameliorating or preventing critical illness is currently lacking. This chapter looks at the approach to diagnosis of critical illness, including the pitfalls in diagnosis.


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