Topic:Blood Gas Analysis
Blood gas analysis in horses involves the measurement of gases and pH levels in blood to assess respiratory and metabolic function. This diagnostic tool provides information on oxygen and carbon dioxide levels, as well as acid-base balance, which are critical for evaluating the respiratory efficiency and metabolic state of equine patients. Blood gas parameters commonly measured include partial pressures of oxygen (PaO2) and carbon dioxide (PaCO2), bicarbonate (HCO3-), and blood pH. These measurements aid in the diagnosis and management of respiratory disorders, metabolic imbalances, and conditions affecting the horse's overall health. This page compiles peer-reviewed research studies and scholarly articles that explore the methodology, interpretation, and clinical applications of blood gas analysis in equine medicine.
Effects of 2 modes of positive pressure ventilation on respiratory mechanics and gas exchange in foals. Continuous positive airway pressure (CPAP) and pressure support ventilation (PSV) can improve respiratory mechanics and gas exchange, but different airway pressures have not been compared in foals. Objective: Assess the effect of different airway pressures during CPAP and PSV have on respiratory function in healthy foals with pharmacologically induced respiratory insufficiency. We hypothesized that increased airway pressures would improve respiratory mechanics and increased positive end-expiratory pressure (PEEP) would be associated with hypercapnia. Methods: Six healthy foals from a universit...
Arterial blood gas tensions during recovery in horses anesthetized with apneustic anesthesia ventilation compared with conventional mechanical ventilation. To compare PaO2 and PaCO2 in horses recovering from general anesthesia maintained with either apneustic anesthesia ventilation (AAV) or conventional mechanical ventilation (CMV). Methods: Randomized, crossover design. Methods: A total of 10 healthy adult horses from a university-owned herd. Methods: Dorsally recumbent horses were anesthetized with isoflurane in oxygen [inspired oxygen fraction = 0.3 initially, with subsequent titration to maintain PaO2 ≥ 85 mmHg (11.3 kPa)] and ventilated with AAV or CMV according to predefined criteria [10 mL kg-1 tidal volume, PaCO2 40-45 mmHg (5.3-6.0 kP...
Effects of total parenteral nutrition associated with glutamine, enteral fluid therapy with or without glutamine, and fluid therapy on the acid-base and electrolyte balance of horses starved after exploratory laparotomy. This study aimed to evaluate the effects of the total parenteral nutrition associated with glutamine, enteral fluid therapy with or without glutamine, and fluid therapy on the acid-base and electrolyte balance of horses starved after exploratory laparotomy. Sixteen healthy male and female adult horses of mixed breed, aged between 4 and 14 years, and having a mean body weight of 248.40 ± 2.28 kg and a body score index of 3-4 (scale of 1-5) were divided into four groups with four animals per group. After an adaptation period of 30 days, they were randomly divided into four experimental groups: ...
Prerace venous blood gases and acid-base values in Standardbred horses: effects of geography, season, prerace furosemide, gender, age, and trainer using big data analytics. A retrospective study was conducted to establish the prerace venous acid-base and blood gas values of Standardbred horses at rest using big data analytics. Methods: Venous blood samples (73,382) were collected during seven racing seasons from 3 regional tracks in the Commonwealth of Pennsylvania. Horses were detained 2 hours prior to race time. Methods: A mixed-effects linear regression model was used for estimating the marginal model adjusted mean (marginal mean) for all major outcomes. The interaction between age and gender, track, and the interaction between month, treatment (furosemide), a...
Effects of detomidine or romifidine during maintenance and recovery from isoflurane anaesthesia in horses. To evaluate the effects of detomidine or romifidine on cardiovascular function, isoflurane requirements and recovery quality in horses undergoing isoflurane anaesthesia. Methods: Prospective, randomized, blinded, clinical study. Methods: A total of 63 healthy horses undergoing elective surgery during general anaesthesia. Methods: Horses were randomly allocated to three groups of 21 animals each. In group R, horses were given romifidine intravenously (IV) for premedication (80 μg kg), maintenance (40 μg kg hour) and before recovery (20 μg kg). In group D2.5, horses were given detomidine IV f...
Effects of intravenous ethyl pyruvate on cardiopulmonary variables and quality of recovery from anesthesia in horses. To determine the effects of intravenous ethyl pyruvate, an anti-inflammatory with putative benefits in horses with endotoxemia, on cardiopulmonary variables during anesthesia and the quality of anesthetic recovery. Methods: Randomized, crossover, blinded experimental design. Methods: A total of six healthy Standardbred geldings, aged 13 ± 3 years and weighing 507 ± 66 kg (mean ± standard deviation). Methods: Horses were anesthetized for approximately 90 minutes on two occasions with a minimum of 2 weeks apart using xylazine for sedation, ketamine and diazepam for induction, and isoflurane i...
Evaluation of the Effects of Doxapram in Combination with Xylazine on Recovery of Horses Isoflurane-Anesthetized. This randomized double-blinded study evaluated the recovery from isoflurane anesthesia in horses receiving doxapram and xylazine. 6 horses were anesthetized 4 times (minimum of 2-week washout period). Anesthesia was performed with xylazine (0.6 mg/kg), ketamine (2.2 mg/kg), midazolam (0.1 mg/kg), and maintained with isoflurane for 90 minutes. At recovery, horses received one of the following randomized treatments: RX: xylazine (0.2 mg/kg), RXD1: xylazine (0.2 mg/kg) and doxapram (0.1 mg/kg), RXD2: xylazine (0.2 mg/kg) and doxapram (0.2 mg/kg), or RS: saline. Recoveries were rope-assisted and e...
Continuous measurement of arterial oxygenation in mechanically ventilated horses. The possibility of accurately and continuously measuring arterial oxygen partial pressure (PaO2 ) in horses may facilitate the management of hypoxaemia during general anaesthesia. Objective: The aim of this study was to evaluate the ability of a novel fibreoptic sensor to measure PaO2 (PaO2Sensor ) continuously and in real time in horses undergoing ventilatory manoeuvres during general anaesthesia. Methods: In vivo experimental study. Methods: Six adult healthy horses were anaesthetised and mechanically ventilated in dorsal recumbency. A fibreoptic sensor was placed in one of the facial arteri...
Effect of different inspired fractions of oxygen on F-shunt and arterial partial pressure of oxygen in isoflurane-anaesthetized and mechanically ventilated Shetland ponies. To determine the effect of fraction of inspired oxygen (FiO) on intrapulmonary shunt fraction as measured by F-shunt in ponies during isoflurane anaesthesia. Methods: Prospective, randomized clinical study. Methods: A group of 23 adult Shetland ponies undergoing a total of 32 anaesthetic procedures. Methods: Ponies were premedicated intravenously (IV) with detomidine (0.01 mg kg) and either morphine (0.1 mg kg) or butorphanol (0.02 mg kg). Anaesthesia was induced with ketamine (2.2 mg kg) and midazolam (0.07 mg kg) administered IV. Ponies were randomly allocated to maintenance of anaesthesia w...
Evaluation of Medetomidine-Ketamine for Immobilization of Feral Horses in Romania. Feral horses are immobilized for a variety of reasons including population control via contraceptives. Although opioid combinations have been successfully used for immobilization of feral horses, there is a need for combinations using drugs that are more readily available and present less of a human health hazard. We evaluated the chemical immobilization with physiological measurements and blood gas analyses of 91 free-ranging feral horses () remotely immobilized with a combination of 30 mg medetomidine and 775 mg ketamine in a single disposable 6 ml dart. During immobilization, heart rate, re...
Selected hematological, biochemical, and acid-base variables of Paso Fino horses living at different altitudes. This study aimed at describing selected hematological, biochemical, and acid-base variables of adult horses living at sea level and comparing them to those living at 5 different altitudes. One hundred and thirty-eight healthy Paso Fino horses > 2 years old were enrolled. Altitudes included the following: altitude A (0 to 50 m above sea level, masl; n = 23), B (1000 to 1050 masl; n = 25), C (1450 masl; n = 30), D (1950 to 2050 masl; n = 30), and E (2950 to 3100 masl; n = 30). A portable blood gas analyzer was used to determine selected biochemical and acid-base variab...
Arterial oxygenation in anesthetized horses placed in a 5-degree reverse Trendelenburg position. Low arterial oxygen is a common complication in anesthetized horses and placing the animal in reverse Trendelenburg (RT) position may treat hypoxemia. The objective of this study was to assess the arterial partial pressure of oxygen (PaO) in horses placed in a 5-degree RT compared to horizontal (H) position. Client-owned healthy horses (n = 60) undergoing elective surgeries were enrolled in a randomized controlled clinical study. Horses were sedated with butorphanol, an α-adrenoceptor agonist, ± acepromazine and induced with ketamine combined with a benzodiazepine, propofol, or guaifenesin...
Peripartum findings and blood gas analysis in newborn foals born after spontaneous or induced parturition. Induction of parturition in horses is still not well accepted due to the potential peripartum complications for mares and newborn foals. We assessed differences after spontaneous and induced parturition with low doses of oxytocin (OX) in 1) incidence of peripartum complications in mares; 2) viability, behavioral, physical, and venous blood gas analyses in foals. In this study 61 mares were included; 45/61 were enrolled in the spontaneous foaling group (SF) and 16/61 in the induced foaling group (IF). In the IF group, when the calcium in mammary secretion reached concentrations of ≥250 ppm, ...
Tramadol Effects on Lameness Score After Inhibition of P-GP by Ivermectin Administration in Horses: Preliminary Results. This study aimed to evaluate the effects and lameness degree in horses administered tramadol after the P-glycoprotein (P-gp) enteric inhibitor ivermectin. Six horses were randomly distributed into three groups, which received two different doses of tramadol by a nasogastric tube: 1Â mg/kg (tramadol group 1(GT1)), 4Â mg/kg (tramadol group 4 (GT4)), and tramadol 1Â mg/kg combined with ivermectin 0.2Â mg/kg PO (ivermectin tramadol group (GT1Â + Ive)), with one-week washout interval. Heart rate (HR), respiratory rate (RR), intestinal motility, body temperature, and the degree of lameness were eval...
Effect of Methadone Combined With Acepromazine or Detomidine on Sedation and Dissociative Anesthesia in Healthy Horses. The aim of this study was to compare the effects of methadone combined with detomidine or acepromazine on the quality of sedation and its influence over dissociative anesthesia in healthy horses. In a crossover design, seven horses were administered with 0.1Â mg/kg methadone and 0.02Â mg/kg detomidine intravenously (group MD) or 0.1Â mg/kg methadone and 0.05Â mg/kg acepromazine intravenously (group MA). Subsequently, anesthesia was induced with a combination of 2.2Â mg/kg ketamine and 0.1Â mg/kg midazolam intravenously. Descriptive scales and footages were used to evaluate the quality of sedat...
Determination of reference intervals for equine arterial blood-gas, acid-base and electrolyte analysis. To establish reference intervals for arterial blood-gas (ABG), acid-base and electrolyte values from a healthy equine population. Methods: Retrospective clinical study. Methods: A total of 139 client-owned, systemically healthy horses, 1 year of age and older, presented for elective surgical procedures. Methods: Blood samples were collected anaerobically from the transverse facial or common carotid artery of horses breathing room air, prior to administration of preanaesthetic medication. Samples were analysed immediately, without correction for body temperature, using an automated bench-top an...
Evaluation of Sevoflurane Anesthesia in Donkeys (Equus asinus) Premedicated With Xylazine and Induced With Thiopental. Sevoflurane is a volatile anesthetic agent that has become popular in the field of large animal anesthesia. The aim of this study was to evaluate the use of sevoflurane in adult healthy donkeys. Six male, adult, healthy donkeys were premedicated with xylazine (1Â mg/kg IV), induced with thiopental (5Â mg/kg IV), and then maintained for 90Â minutes with sevoflurane in 100% oxygen at a flow rate of 6Â L/min with spontaneous breathing. Rectal temperature (RT), respiratory rate, heart rate (HR), oxygen hemoglobin saturation (OHS), and mean arterial blood pressure (MBP) were measured before and 20Â...
Comparison of two portable clinical analyzers to one stationary analyzer for the determination of blood gas partial pressures and blood electrolyte concentrations in horses. Portable blood gas analyzers are used to facilitate diagnosis and treatment of disorders related to disturbances of acid-base and electrolyte balance in the ambulatory care of equine patients. The aim of this study was to determine whether 2 portable analyzers produce results in agreement with a stationary analyzer. Blood samples from 23 horses hospitalized for various medical reasons were included in this prospective study. Blood gas analysis and electrolyte concentrations measured by the portable analyzers VetStat and epoc were compared to those produced by the cobas b 123 analyzer via conco...
Cardiopulmonary effects and recovery characteristics of horses anesthetized with xylazine-ketamine with midazolam or propofol. To evaluate cardiopulmonary and recovery characteristics of horses administered total intravenous anesthesia (TIVA) with xylazine and ketamine combined with midazolam or propofol. Methods: Randomized crossover study. Methods: A group of eight adult horses, aged 7-22 years, weighing 493-740 kg. Methods: Horses were administered xylazine (1 mg kg) intravenously (IV), and anesthesia was induced with ketamine (2.2 mg kg) IV. Anesthesia was maintained for 45 minutes via IV infusion of xylazine (0.016 mg kg minute) and ketamine (0.03 mg kg minute) combined with midazolam at 0.002 mg kg minute (MKX),...
Comparison of desflurane and propofol at equipotent doses in combination with a constant rate infusion of dexmedetomidine on global and peripheral perfusion and oxygenation in horses. OBJECTIVE To determine global and peripheral perfusion and oxygenation during anesthesia with equipotent doses of desflurane and propofol combined with a constant rate infusion of dexmedetomidine in horses. ANIMALS 6 warmblood horses. PROCEDURES Horses were premedicated with dexmedetomidine (3.5 μg•kg, IV). Anesthesia was induced with propofol or ketamine and maintained with desflurane or propofol (complete crossover design) combined with a constant rate infusion of dexmedetomidine (7 μg•kg •h). Microperfusion and oxygenation of the rectal, oral, and esophageal mucosa were measured bef...
Clinical comparison of dexmedetomidine and medetomidine for isoflurane balanced anaesthesia in horses. To compare the effects of two balanced anaesthetic protocols (isoflurane-dexmedetomidine versus medetomidine) on sedation, cardiopulmonary function and recovery in horses. Methods: Prospective, blinded, randomized clinical study. Methods: Sixty healthy adult warm blood horses undergoing elective surgery. Methods: Thirty horses each were sedated with dexmedetomidine 3.5 μg kg (group DEX) or medetomidine 7 μg kg (group MED) intravenously. After assessing and supplementing sedation if necessary, anaesthesia was induced with ketamine/diazepam and maintained with isoflurane in oxygen/air and ...
Effects of dystocia on blood gas parameters, acid-base balance and serum lactate concentration in heavy draft newborn foals. Dystocia is often lethal for neonatal foals; however, its clinicopathological features remain largely unknown. We investigated the effect of dystocia on the foal blood profile. Venous blood samples were collected from 35 foals (5 Percheron and 30 crossbreds between Percheron, Belgian, and Breton heavy draft horses) at 0 hr, 1 hr, 12 hr and 1 day after birth. Dystocia was defined as prolonged labor >30 min with strong fetal traction with or without fetal displacement. The dystocia group (n=13) showed lower mean values for pH (P<0.01), bicarbonate (P<0.01), total carbon dioxide (P<0....
Effects of intravenous terbutaline on heart rate, arterial pressure and blood gases in anesthetized horses breathing air. To investigate the effects of intravenous (IV) administration of terbutaline on PaO, PaCO, pH, heart rate (HR) and arterial pressures in healthy, laterally recumbent horses breathing ambient air under total intravenous anesthesia (TIVA). Methods: Prospective experimental study. Methods: Eight healthy adult horses were enrolled. Six horses, four mares and two geldings weighing 433-624 kg, completed the study. Methods: Horses were sedated with xylazine (1.0 mg kg) IV for placement of arterial and venous catheters. Anesthesia was induced with midazolam (0.1 mg kg) and ketamine (2.2 mg kg) IV and ...
Evaluation of a new handheld point-of-care blood gas analyser using 100 equine blood samples. To determine whether the Enterprise point-of-care blood analysis system (EPOC) produces results in agreement with two other blood gas analysers in regular clinical use (i-STAT and Radiometer ABL77) and to investigate the precision of the new machine when used with equine whole blood. Prospective, randomized, non-blinded, comparative laboratory analyser study. Horses admitted to a university teaching hospital requiring arterial or venous blood gas analysis as part of their routine clinical management. One hundred equine blood samples were run immediately, consecutively and in randomized order o...
Effects of thiopentone on the equine electroencephalogram during anaesthesia with halothane in oxygen. To characterise the effects of thiopentone on the equine electroencephalogram during halothane anaesthesia. Methods: Prospective controlled study. Methods: Eight healthy Welsh mountain pony geldings between 5 and 9 years old and weighing between 270 and 330 kg (mean 301 kg). Methods: Anaesthesia was induced with thiopentone and maintained using halothane in oxygen. End tidal halothane was maintained above 0.75 and below 0.85%. EEG was recorded continuously and a binaural broad band click stimulus was provided throughout the experiment at 6.1224 Hz. An infusion of 500 mg thiopentone was given o...
Aerosolized salbutamol (albuterol) improves PaO2 in hypoxaemic anaesthetized horses – a prospective clinical trial in 81 horses. To compare the arterial pH and blood gas values, heart rate and mean arterial blood pressure, in hypoxaemic anaesthetized horses, before and after treatment, with a salbutamol (albuterol) aerosol. Methods: Eighty-one client-owned horses weighing between 114 and 925 kg. Fifty-seven underwent emergency abdominal surgery and 24 were anaesthetized for elective procedures. Methods: Pre-anaesthetic medication included xylazine, detomidine, butorphanol and morphine, alone or in various combinations. Induction of anaesthesia was achieved with guaifenesin and ketamine, diazepam and ketamine, or guaifen...
An evaluation of apnea or spontaneous ventilation in early recovery following mechanical ventilation in the anesthetized horse. To compare arterial oxygen and carbon dioxide tensions in apneic and spontaneously ventilating horses recovering from anesthesia. Methods: Randomized clinical trial. Methods: Forty-two healthy horses averaging 466 ± 106 kg and 6 ± 5 years of age. Methods: Anesthetized horses undergoing a variety of surgical procedures and receiving positive pressure ventilation (IPPV) were divided into two equal groups. One group was allowed to return to spontaneous ventilation prior to disconnection from the anesthetic circuit (weaned). The other group remained apneic during transport to a recovery stall. A...
Intravenous anaesthesia using detomidine, ketamine and guaiphenesin for laparotomy in pregnant pony mares. Objective To characterize intravenous anaesthesia with detomidine, ketamine and guaiphenesin in pregnant ponies. Animals Twelve pony mares, at 260-320 days gestation undergoing abdominal surgery to implant fetal and maternal vascular catheters. Materials and methods Pre-anaesthetic medication with intravenous (IV) acepromazine (30 µg kg), butorphanol (20 µg kg) and detomidine (10 µg kg) preceded induction of anaesthesia with detomidine (10 µg kg) and ketamine (2 mg kg) IV Maternal arterial blood pressure was measured directly throughout anaesthesia and arterial blood samples were taken at ...
Expression of T helper cell-associated inflammatory mediator mRNAs in cells of bronchoalveolar lavage fluid samples and oxygen concentration in arterial blood samples from healthy horses exposed to hyperbaric oxygen. OBJECTIVE To evaluate the mRNA expression of T helper (Th)1, Th2, and Th17 cell-associated inflammatory mediators in cells of bronchoalveolar lavage fluid samples collected from healthy horses exposed to hyperbaric oxygen (HBO) and to monitor blood oxygen concentration during and following HBO therapy. ANIMALS 8 healthy horses. PROCEDURES In a randomized controlled crossover design study, each horse was exposed (beginning day 1) to 100% oxygen at a maximum of 3 atmospheres absolute (304 kPa) daily for 10 days or ambient air at atmospheric pressure in the HBO chamber for an equivalent amount of...
Efficacy of a portable oxygen concentrator with pulsed delivery for treatment of hypoxemia during equine field anesthesia. Hypoxemia is common during equine field anesthesia. Our hypothesis was that oxygen therapy from a portable oxygen concentrator would increase PaO2 during field anesthesia compared with the breathing of ambient air. Methods: Prospective clinical study. Methods: Fifteen yearling (250 - 400Â kg) horses during field castration. Methods: Horses were maintained in dorsal recumbency during anesthesia with an intravenous infusion of 2000Â mg ketamine and 500Â mg xylazine in 1Â L of 5% guaifenesin. Arterial samples for blood gas analysis were collected immediately post-induction (PI), and at 15 and 30Â...