scholarly journals Total Intravenous Anaesthesia with Ketamine, Medetomidine and Midazolam as Part of a Balanced Anaesthesia Technique in Horses Undergoing Castration

2021 ◽  
Vol 8 (8) ◽  
pp. 142
Author(s):  
Alexandra Cunneen ◽  
Shaun Pratt ◽  
Nigel Perkins ◽  
Margaret McEwen ◽  
Geoffrey Truchetti ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Muscle Relaxation ◽  
Recovery Period ◽  
Blood Gases ◽  
Anaesthetic Technique ◽  
Physiological Variables ◽  
Arterial Partial Pressure ◽  
Arterial Blood ◽  
Anaesthetic Depth

To evaluate the use of ketamine-medetomidine-midazolam total intravenous infusion as part of a balanced anaesthetic technique for surgical castration in horses. Five healthy Standardbred cross colts were premedicated with IV acepromazine (0.01–0.02 mg/kg), medetomidine (7 µg/kg) and methadone (0.1 mg/kg) and anaesthesia induced with IV ketamine (2.2 mg/kg) and midazolam (0.06 mg/kg). Horses were anaesthetised for 40 min with an IV infusion of ketamine (3 mg/kg/h), medetomidine (5 µg/kg/h) and midazolam (0.1 mg/kg/h) while routine surgical castration was performed. Cardiorespiratory variables, arterial blood gases, and anaesthetic depth were assessed at 5 to 10 min intervals. Post-anaesthesia recovery times were recorded, and the quality of the recovery period was assessed. The anaesthetic period and surgical conditions were acceptable with good muscle relaxation and no additional anaesthetic required. The median (range) time from cessation of the infusion to endotracheal tube extubation, head lift and sternal recumbency were 17.2 (7–35) min, 25 (18.9–53) min and 28.1 (23–54) min, respectively. The quality of anaesthetic recovery was good, with horses standing 31.9 (28–61) min after the infusion was ceased. During anaesthesia, physiological variables, presented as a range of median values for each time point were: heart rate 37–44 beats/min, mean arterial pressure 107–119 mmHg, respiratory rate 6–13 breaths/min, arterial partial pressure of oxygen 88–126 mmHg, arterial partial pressure of carbon dioxide 52–57 mmHg and pH 7.36–7.39. In conclusion, the co-administration of midazolam, ketamine and medetomidine as in IV infusion, when used as part of a balanced anaesthetic technique, was suitable for short term anaesthesia in horses undergoing castration.

Measurement of arterial blood gases at the transition from exercise to rest

1983 ◽  
Vol 54 (5) ◽  
pp. 1340-1344 ◽  
Author(s):  
B. M. Lewis
Keyword(s):  
Partial Pressure ◽  
Blood Gases ◽  
Normal Subjects ◽  
Forced Expiratory Volume ◽  
Stair Climbing ◽  
Regulation Of Respiration ◽  
Arterial Blood Gas ◽  
Arterial Partial Pressure ◽  
Arterial Blood ◽  
Two Samples

Arterial blood gas samples obtained 5–20 s after stair-climbing exercise were compared with samples taken during the last 30 s of exercise in 137 subjects. Arterial partial pressure of CO2 (PaCO2) did not change significantly, and in 110 subjects the two samples were within the analytical variation (+/- 2 Torr), supporting the cardiodynamic hypothesis of respiratory regulation. Exceptions to this response were 10 subjects who hyperventilated (PaCO2 less than 34) during exercise and 15 with severe obstruction [forced expiratory volume in 1 s (FEV1) less than 70% forced vital capacity (FVC), and FVC less than 70% of predicted] in whom PaCO2 increased significantly. Overall, arterial partial pressure of O2 (PaO2) increased an average of 3.49 Torr (P less than 0.001). In the two groups in which PaCO2 increased, postexercise PaO2 did not rise. In addition, duration of exercise affected PaO2 response. PaO2 increased significantly more after brief (less than 2 min) periods than after longer (4–6 min) exercise, and this difference increased only when subjects with normal or borderline ventilatory function were analyzed. In 13 subjects in whom a second sample was taken 30–45 s after exercise, the increase in PaO2 was progressive and again the difference between short and long exercise was evident. Regulation of respiration to maintain PaCO2 and changes in O2-CO2 kinetics, leading to an increase in the gas exchange ratio at the exercise-rest transition, are the most likely explanations of these data which establish that the usual response to stopping exercise in normal subjects and most patients is an unchanged PaCO2 and a variable increase in PaO2.

scholarly journals Impact of inspiratory muscle training on diaphragmatic mobility and arterial blood gases in patients undergoing haemodialysis

2021 ◽  
Vol 28 (5) ◽  
pp. 1-8
Author(s):  
Fatma Aboelmagd ◽  
Samah M Ismail
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Partial Pressure ◽  
Physical Function ◽  
Outcome Measures ◽  
Blood Gases ◽  
Daily Routine ◽  
Arterial Blood Gases ◽  
Arterial Partial Pressure ◽  
Arterial Blood

Background/aims Impairment of respiratory muscle function is common in patients with chronic kidney disease undergoing haemodialysis, and is manifested by decreased oxygenation and physical function. The purpose of this study was to analyse the impact of training with incentive spirometer on mobility of the diaphragm, arterial blood gases and functional capacity in patients with chronic kidney disease undergoing haemodialysis. Methods A pre–post research design was implemented. A total of 30 patients undergoing haemodialysis for chronic kidney disease received incentive spirometer training intradialysis three sessions a week for 8 weeks. Outcome measures were the amount of diaphragmatic mobility measured by ultrasonography, the levels of arterial partial pressure of oxygen, arterial partial pressure of carbon dioxide, oxygen saturation percentages and the distance walked in 6 minutes. Results Significant improvement from pre-treatment to post-treatment measurements occurred in all outcome measures, with P<0.05. Conclusions Incentive spirometer training should be recommended to be a part of daily routine of patients with chronic kidney disease who are undergoing haemodialysis to decrease respiratory and physical function impairments.

In Vivo Analysis of Gas Transport in Arterial and Venous Blood of the Sea Lamprey Petromyzon Marinus

1992 ◽  
Vol 169 (1) ◽  
pp. 105-119
Author(s):  
B. L. TUFTS ◽  
B. BAGATTO ◽  
B. CAMERON
Keyword(s):  
Partial Pressure ◽  
Whole Blood ◽  
Venous Blood ◽  
Recovery Period ◽  
Co2 Concentration ◽  
Extracellular Acidosis ◽  
Arterial Blood ◽  
Sea Lampreys ◽  
In Vivo Analysis

Exercise in sea lampreys resulted in a significant decrease in the extracellular pH (pHe) in both arterial and venous blood. At rest, the erythrocyte pH (pHi) of venous blood was significantly greater than the pHi of arterial blood. Despite the considerable extracellular acidosis after exercise, both arterial and venous pHi were maintained throughout the recovery period. In the venous blood, there was a reversal of the pH gradient (ΔpH) across the erythrocyte membrane immediately after exercise. Exercise also resulted in significant reductions in the partial pressure of oxygen and hemoglobin oxygen-carriage and a significant increase in the partial pressure of CO2 in arterial and venous blood. Although the total CO2 concentration of the plasma decreased after exercise, erythrocyte total CO2 concentrations (CCOCO2,i) increased. In venous blood, the CCOCO2,i immediately after exercise was double the resting value. At rest, partitioning of the total CO2 content between plasma and erythrocytes indicated that 16 % and 22 % of the total CO2 could be attributed to the erythrocytes in arterial and venous whole blood, respectively. After exercise, these percentages increased to 25% (arterial) and 38% (venous). Changes in CCOCO2,i accounted for 62% of the arteriovenous difference in whole-blood total CO2 at rest. This increased to 78% immediately after exercise. Thus, unlike other vertebrates, CO2 transport in the lamprey in vivo is largely dependent on erythrocyte CO2-carriage.

scholarly journals Effects of Induced Haemorrahge on Thermoregulation, Blood Constituents and Serum Biochemical Parameters in Pregnant and Non-Pregnant Rabbits (Oryctolagus cuniculus)

2019 ◽  
pp. 1-15
Author(s):  
Khalid A. O. Sukar ◽  
Abdalla M. Abdelatif ◽  
Ahmed O. Alameen
Keyword(s):  
Partial Pressure ◽  
Biochemical Parameters ◽  
Plasma Osmolality ◽  
Blood Gases ◽  
Arterial Oxygen ◽  
Total Blood ◽  
Mortality And Morbidity ◽  
Blood Constituents ◽  
Arterial Blood ◽  
Serum Biochemical

Background and Objectives: Haemorrhage is a leading cause of mortality and morbidity of mother and foetus. Pregnancy is associated with changes which may influence responses to bleeding. This study was designed to examine the influence of controlled haemorrhage and compare thermoregulation and haematological and biochemical parameters in pregnant and nonpregnant rabbits. Materials and Methods: Twelve pregnant and nonpregnant rabbits, 6 in each group, were used in the studies. Both groups of animals were subjected to 20% haemorrhage of total blood volume on gestation day 21. The rectal temperature (Tr), respiratory rate (RR) and heart rate (HR) were monitored for 2 days following bleeding. Blood samples were collected at 24 hrs before induction of bleeding and then after bleeding at 30 min, 24 hrs and 48 hrs. The samples were used for measurements of haematological parameters; coagulation profile, arterial blood gases and serum electrolytes. Results: The general trend indicates lower Tr values in pregnant rabbits at 30 min post-haemorrhage. The values of RR and HR were significantly (P ≤ 0.01) higher in pregnant and nonpregnant animals at 24 hrs post-haemorrhage. The pregnant rabbits showed significant (P<0.05) decrease in platelets count at 24 hrs post-haemorrhage compared to the nonpregnant values. In pregnant rabbits, haemorrhage was associated with significant increase in PT. The activated partial thromboplastin time (APTT) was significantly (P≤ 0.01) prolonged at 24 hrs post-haemorrhage in pregnant and nonpregnant rabbits. The partial pressure of arterial oxygen (PaO2) in pregnant and nonpregnant rabbits was significantly (P≤ 0.01) increased at 24hrs and 48 hrs post-haemorrhage. The partial pressure of arterial carbon dioxide (PaCO2) decreased significantly (P≤0.01) at 30 min post-haemorrhage in pregnant rabbits. There was a slight increase in Na and Ca levels in pregnant rabbits’ post-haemorrhage. Haemorrhage in rabbits was associated with significant decreases in plasma osmolality in pregnant rabbits. Conclusion: Pregnancy induces modifications in some physiological responses to haemorrhage. The information generated could be used in monitoring maternal health during pregnancy and risks of changes associated with haemorrhage in mammals.

Respiratory changes induced by prolonged laryngeal stimulation in awake piglets

1986 ◽  
Vol 61 (3) ◽  
pp. 1018-1024 ◽  
Author(s):  
D. F. Donnelly ◽  
G. G. Haddad
Keyword(s):  
Blood Pressure ◽  
Partial Pressure ◽  
Minute Ventilation ◽  
Young Animal ◽  
Whole Body ◽  
Electrode Placement ◽  
Base Line ◽  
Stimulus Period ◽  
Arterial Partial Pressure ◽  
Arterial Blood

To examine the role of the laryngeal reflex in modulating cardiorespiratory function, we stimulated the superior laryngeal nerves (SLN) bilaterally in unanesthetized, chronically instrumented piglets (n = 10, age 5–14 days). The SLN were placed in cuff electrodes and wires were exteriorized in the neck for stimulation. A cannula placed in the aorta was used for blood pressure recording and arterial blood sampling. During each experiment, 1–2 days after surgery, ventilation was recorded using whole-body plethysmography, and electroencephalogram and electrocardiogram were recorded after acute subcutaneous electrode placement. After base-line recordings, the SLN were electrically stimulated for 1 h. During this period, mean respiratory frequency decreased by 40–75% and apneas of 10–15 s were regularly interspersed between single breaths or clusters of breaths. Periods of breathing were always associated with opening of the eyes and generally with head and body movements, an awakening that occurred every 10–15 s. At 1 h into the stimulus period, minute ventilation had decreased by 57 +/- 7% (mean +/- SE), arterial partial pressure of O2 (PaO2) by 68 +/- 3 Torr, and arterial partial pressure of CO2 (PaCO2) had increased by 19 +/- 2 Torr. Throughout the entire stimulus period, mean blood pressure and average heart rate were maintained within 12% of base line. We suggest that: low-threshold SLN afferents exert primarily respiratory effects and only minor cardiovascular effects; breathing during laryngeal reflex activation is sustained by an arousal system; and the laryngeal reflex does not pose an imminent threat to the unanesthetized, awake, young animal.

Clinical and pathological features of fat embolism with acute respiratory distress syndrome

2007 ◽  
Vol 113 (6) ◽  
pp. 279-285 ◽  
Author(s):  
Shang Jyh Kao ◽  
Diana Yu-Wung Yeh ◽  
Hsing I. Chen
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Partial Pressure ◽  
Alveolar Macrophages ◽  
Distress Syndrome ◽  
Fat Embolism ◽  
Arterial Partial Pressure ◽  
Arterial Blood ◽  
Blood Ph

FES (fat embolism syndrome) is a clinical problem, and, although ARDS (acute respiratory distress syndrome) has been considered as a serious complication of FES, the pathogenesis of ARDS associated with FES remains unclear. In the present study, we investigated the clinical manifestations, and biochemical and pathophysiological changes, in subjects associated with FES and ARDS, to elucidate the possible mechanisms involved in this disorder. A total of eight patients with FES were studied, and arterial blood pH, PaO2 (arterial partial pressure of O2), PaCO2 (arterial partial pressure of CO2), biochemical and pathophysiological data were obtained. These subjects suffered from crash injuries and developed FES associated with ARDS, and each died within 2 h after admission. In the subjects, chest radiography revealed that the lungs were clear on admission, and pulmonary infiltration was observed within 2 h of admission. Arterial blood pH and PaO2 declined, whereas PaCO2 increased. Plasma PLA2 (phospholipase A2), nitrate/nitrite, methylguanidine, TNF-α (tumour necrosis factor-α), IL-1β (interleukin-1β) and IL-10 (interleukin-10) were significantly elevated. Pathological examinations revealed alveolar oedema and haemorrhage with multiple fat droplet depositions and fibrin thrombi. Fat droplets were also found in the arterioles and/or capillaries in the lung, kidney and brain. Immunohistochemical staining identified iNOS (inducible nitric oxide synthase) in alveolar macrophages. In conclusion, our clinical analysis suggests that PLA2, NO, free radicals and pro-inflammatory cytokines are involved in the pathogenesis of ARDS associated with FES. The major source of NO is the alveolar macrophages.

A comparison between medetomidine-ketamine and medetomidine-propofol anaesthesia in rabbits

1997 ◽  
Vol 31 (1) ◽  
pp. 58-69 ◽  
Author(s):  
Ludo J. Hellebrekers ◽  
Evert-Jan W. de Boer ◽  
Michiel A. van Zuylen ◽  
Hans Vosmeer
Keyword(s):  
Muscle Tone ◽  
Arterial Oxygen Tension ◽  
Arterial Oxygen ◽  
Physiological Variables ◽  
Arterial Blood ◽  
Jaw Muscle ◽  
Before And After ◽  
Anaesthetic Depth ◽  
Low Incidence ◽  
High Degree

We investigated the effects of combinations of the α2-agonist medetomidine with either ketamine or propofol for their overall quality of anaesthesia, including the possible concomitant changes in respiratory and circulatory function in New Zealand White rabbits. Medetomidine was administered at 0.35 mg/kg, intramuscularly. Following sedation, ketamine (5 mg/kg) or propofol (2 and 3 mg/kg) were administered intravenously via the ear vein. Data on reflexes (palpebral, corneal, ear-pinch and toe-pinch), jaw muscle tone and physiologic parameters (heart rate, blood pressure, respiration rate, body temperature) were recorded before and after administration of drugs. Intermittent arterial blood sampling was performed at predetermined intervals before and after anaesthesia. The results show that the ear-pinch and toe-pinch reflexes and the jaw muscle tone are reliable indices to determine surgical anaesthetic depth. A surgical level of anaesthesia could be obtained reliably with the combination medetomidine-ketamine and medetomidine-propofol (3 mg/kg) with a duration of 19 min (variation 10 to 40 min, n=6) and 11 min (variation 5 to 15 min, n=6), respectively. Propofol administered at 2 mg/kg did not produce an adequate anaesthetic level. The data from this study demonstrate a high degree of predictability in achieving a fast induction and adequate anaesthetic depth together with a low incidence of untoward side-effects and a zero mortality with the combinations investigated. The data from the medetomidine-ketamine group show that, although adequate anaesthetic depth of medium duration is achieved, the arterial oxygen tension is reduced to hypoxemic levels. With the use of this combination, the supplemental administration of oxygen is advised. With the combination of medetomidine-propofol (3 mg/kg) a short duration anaesthesia of adequate depth was achieved, whereby physiological variables all remained within acceptable ranges. The use of medetomidine-propofol, in combination with the α2-antagonist atipamezole to shorten recovery time, will provide reliable and very versatile anaesthesia in rabbits.

Exhaustive Exercise in "Wild" Atlantic Salmon (Salmo saiar): Acid–Base Regulation and Blood Gas Transport

1991 ◽  
Vol 48 (5) ◽  
pp. 868-874 ◽  
Author(s):  
B. L. Tufts ◽  
Y. Tang ◽  
K. Tufts ◽  
R. G. Boutilier
Keyword(s):  
Atlantic Salmon ◽  
Partial Pressure ◽  
Recovery Period ◽  
Exhaustive Exercise ◽  
Arterial Oxygen ◽  
Blood Gas ◽  
Partial Pressure Of Oxygen ◽  
Acid Base ◽  
Arterial Oxygen Content ◽  
Arterial Partial Pressure

Wild Atlantic salmon (Salmo salar) collected during their spawning migration were transported to the laboratory to investigate effects of exhaustive exercise on acid–base regulation and blood gas transport. Exhaustive exercise resulted in a very large extracellular acidosis which lasted for about 4 h. Blood lactate levels were extremely high and remained significantly elevated for at least 8 h after exercise. The degree of erythrocyte pH regulation was minimal and there was a significant fall in both erythrocyte pH and haemoglobin:oxygen carriage during the recovery period. Together, the significant decrease in erythrocyte pH and a significant reduction in the arterial partial pressure of oxygen resulted in a significant fall in arterial oxygen content immediately after exercise. Thereafter, arterial oxygen content was maintained by a significant increase in hematocrit and an increase in the arterial partial pressure of oxygen. Despite the extremely large lactacidosis in these wild fish, there were no mortalities during the recovery period. However, significant mortality has been reported in studies on domestic salmonids, and this suggests that wild salmonids may be better adapted for exhaustive exercise. This result supports the rationale of a "catch and release" recreational fishery for Atlantic salmon.

Anesthesia for Carbon Dioxide Laser Microsurgery of the Larynx

1981 ◽  
Vol 89 (5) ◽  
pp. 732-737 ◽  
Author(s):  
Chunilal B. Ruder ◽  
Naomi L. Rapheal ◽  
Allan L. Abramson ◽  
Robert M. Oliverio
Keyword(s):  
Carbon Dioxide Laser ◽  
Muscle Relaxation ◽  
Blood Gases ◽  
Operating Conditions ◽  
Jet Ventilation ◽  
Laser Microsurgery ◽  
Arterial Blood ◽  
Surgical Field ◽  
Intravenous General Anesthesia ◽  
Total Compliance

Jet ventilation via the Sanders injector during intravenous general anesthesia provides excellent operative conditions for CO2 laser microsurgery of the larynx. This technique, which includes complete muscle relaxation, is superior to traditional methods of anesthesia because the endotracheal tube is eliminated, thus improving the surgical field and reducing burn hazards owing to ignition of the tube. The laryngoscope has been modified to carry multiple ports into which a 14-gauge needle is inserted and the tip advanced just distal to the vocal cords. This needle is securely attached to the injector and pressure from the oxygen source is adjusted according to the patient's build and total compliance. Satisfactory arterial blood gases, superb operating conditions, safety, and rapid awakening make this the method of choice for most patients.

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