P.K. Peshin

Bio: P.K. Peshin is an academic researcher from University of Tehran. The author has contributed to research in topics: Sedation & Detomidine. The author has an hindex of 5, co-authored 27 publications receiving 98 citations.

Evaluation of detomidine as a sedative in goats.

Abstract: Intramuscular (i.m.) and intravenous (i.v.) administration of detomidine at doses of 10, 20 and 40 micrograms/kg body mass was evaluated for its sedative and analgesic properties in 15 goats (Capra hircus). The drug produced dose- and route-dependent sedation. The 10 micrograms/kg dose was effective only when administered i.v. There was no observable analgesia at this dose. Higher doses produced effective sedation and moderate analgesia of the body with either route of administration. Severe ataxia and sternal recumbency were seen in all the animals after the dose of 40 micrograms/kg. Other effects of detomidine in these goats included mild to moderate salivation, depressed respiratory rate, decreased rectal temperature, bradycardia and hyperglycaemia. Plasma concentrations of total protein, sodium, potassium and chloride were not affected.

Evaluation of halothane as an anaesthetic in camels (Camelus dromedarius)

Abstract: Summary Halothane as an anaesthetic was evaluated in 12 adult camels, thiopentone being used as an induction agent. In six camels, clinical signs and haematological and blood biochemical changes were investigated while in other six haemodynamic, acid base and blood gas changes were monitored. The dose of thiopentone required to ensure intubation for halothane anaesthesia was 7.25 ± 0.33 mg/kg. A modified technique of tracheal intubation was found to be safe and quick. During halothane administration all anaesthetic effects were predictable. Complete recovery occurred in 39.5 ± 9.8 min after discontinuation of halothane administration. Halothane moderated the thiopentone-induced tachycardia. The mean arterial pressure decreased significantly. There was an increase in the arterial carbon dioxide and venous oxygen tension during halothane anaesthesia and development of hypoxaemia after its discontinuation. The alanine aminotransferase values increased during recovery, while plasma sodium, potassium and calcium decreased. Halothane appears to be safe for camels. However, to avoid hypoxaemia in the immediate post-anaesthetic period, oxygen administration should be continued.

Radiographic visualization of the ruminant upper urinary tract by a double contrast technique

Abstract: The ruminant urinary tract is normally obscured by abdominal viscera, which hampers rediographic investigation by conventional urographic methods. A double contrast technique that uses pneumoperitoneum in conjunction with excretory urography is described. Bolus and infusion urographic techniques were used in sheep and calves. Only the infusion technique was used in cows. The radiographic anatomy of the upper urinary tract in these animals is described. Visualization of the nephrogram and collecting system varied, depending on the method of excretory urography used.

Effects of limb tourniquet ischemia on local and systemic acid-base and blood gases of cattle.

Abstract: Effects of forelimb tourniquet ischemia of 90 minute duration were investigated in six bulls aged two to three years. Studies were also conducted up to 150 minutes after release of the tourniquet. Parameters investigated were pH, PCO2, PO2, oxygen saturation and HCO3. In systemic circulation no variations in different parameters were observed during 90 minutes of ischemia. However, significant increase in arterial and venous pH were observed after 30 and 45 minutes of the release of tourniquet, respectively. These increases were accompanied by an increase in HCO3. In the affected limb, ischemia resulted in severe acidosis with a significant increase in PCO2 and a nonsignificant decrease of HCO3. There was a significant fall in PO2 and oxygen saturation. After release of the tourniquet, limb venous pH increased significantly due to a significant fall in PCO2 and a nonsignificant increase in HCO3. A significant increase in the limb venous PO2 and oxygen saturation post tourniquet was observed up to the end of the experiments. There was evidence of very poor oxygen exchange and utilization up to 150 minutes after release of the tourniquet. These results demonstrated that tourniquet ischemia of 90 minutes duration of the limb of cattle may not be safe.

Clinical evaluation of medetomidine hydrochloride as a sedative and its reversal with atipamizole in camels.

Abstract: Studies were done on six male camels suffering from different surgical ailments (lacerated nostrils, mandibular osteomyelitis developed after mandibular fracture, unilateral mandibular fracture, testicular abscess, maggot wound at punctured sole, removal of sutures after repaired ventral hernia). Medetomidinc hydrochloride (6.0 µg/kg) was administered intravenously and the camels were operated for minor surgical disorders under local anaesthesia. The animals showed the signs of sedation with analgesia. The surgical intervention was carried out without any struggling and discomfort on the part of animals as well as the surgical team members. Immediately after completion of the procedures, atipamezole (30.0 µg/kg) was administered intravenously. All the animals showed uneventful recovery and the camels were on their feet and ready for ambulation within 15.5±0.67 minutes.

Tourniquet release: systemic and metabolic effects.

Abstract: The pneumatic tourniquet produces ischemic changes in limbs. The effects of tourniquet release on systemic blood pressure and metabolic parameters were studied in 11 adult patients undergoing total knee replacement under general anesthesia. Mean arterial pressure (MAP) decreased rapidly after the release of the tourniquet, becoming significant at 3 min and remaining significantly depressed up to 15 min post release. Arterial pH, PaO2, PaCO2, lactate acid, and potassium changed significantly after the release, but normalized within 30 min. These results are notably different from a previous study in a similar patient population undergoing knee replacement under epidural anesthesia. Compared to patients under epidural anesthesia, patients receiving general anesthesia with mechanical ventilation are unable to compensate for the metabolic load caused by the tourniquet release, as the latter group are unable to alter their ventilatory rate. In elderly patients with decreased cardio-pulmonary reserve, this may be of clinical importance.

General Anesthetic Techniques in Ruminants

Abstract: This article reviews the injectable and inhalant techniques used for general anesthesia in cattle, sheep, and goats. Particular attention is given to recently developed injectable and inhalant drugs that are currently available in the United States. Perioperative care, including preoperative preparation and perioperative analgesia, is also addressed.

The role of gravity in the evolution of mammalian blood pressure.

Abstract: Understanding of the factors involved in determining the level of central arterial blood pressure in mammals has been clouded by inappropriate allometric analyses that fail to account for phylogenetic relationships among species, and require pressure to approach 0 as body size decreases. The present study analyses systolic, mean arterial, and diastolic blood pressure in 47 species of mammal with phylogenetically informed techniques applied to two-parameter equations. It also sets nonlinear, three-parameter equations to the data to remove the assumption of the two-parameter power equation that the smallest animals must have negligible blood pressure. These analyses show that blood pressure increases with body size. Nonlinear analyses show that mean blood pressure increases from 93 mmHg in a 10 g mouse to 156 mmHg in a 4 tonne elephant. The scaling exponent of blood pressure is generally lower than, though not significantly different from, the exponent predicted on the basis of the expected scaling of the vertical distance between the head and the heart. This indicates that compensation for the vertical distance above the heart is not perfect and suggests that the pressure required to perfuse the capillaries at the top of the body may decrease in larger species.

Upregulation of collecting duct aquaporin-2 by metabolic acidosis: role of vasopressin.

Abstract: Metabolic acidosis is associated with alteration in fluid and electrolyte reabsorption in a number of nephron segments. However, the effects of metabolic acidosis on urine osmolality and aquaporin-...