Reversed patent ductus arteriosus and multiple congenital malformations in an 8‐day‐old Arabo‐Friesian foal

An 8‐day‐old Arabo‐Friesian filly was presented with signs of severe dyspnoea, tachypnoea, coughing and cyanotic mucous membranes. On auscultation, a bilateral grade V/VI continuous heart murmur and heart rate of 155 beats/min (sinus tachycardia) were detected. Lung ultrasonography revealed pronounced comet tail artefacts indicating lung oedema. Echocardiography showed right ventricular hypertrophy, a 1.2 cm muscular ventricular septal defect with a left‐to‐right shunt, a stenotic bicuspid pulmonary valve and severe mitral and tricuspid valve regurgitation. Tricuspid regurgitation peak velocity indicated a right ventricular systolic pressure of 119 mmHg. The pulmonary artery was severely dilated and a 1 cm diameter patent ductus arteriosus was found. Colour flow Doppler showed systolic ductal flow reversal with right‐to‐left shunting through the ductus. Arterial partial oxygen pressure and saturation were lower in the metatarsal artery (25 mmHg, saturation 52.6%) than in the carotid artery (31 mmHg, saturation 64.3%). Due to the poor prognosis, the foal was subjected to euthanasia and necropsy confirmed the ultrasonographic findings. Patent ductus arteriosus is a rare condition and occurs most frequently in combination with tetralogy and pentalogy of Fallot. A genetic basis for congenital cardiac disease, especially for ventricular septal defects, in Arabians and for aortic rupture and aorto‐pulmonary fistulation in Friesians has been reported. Whether cross‐breeding leads to an increased prevalence is unknown. This is the first case report with echocardiographic visualisation of reversed ductal flow in a neonatal Arabo‐Friesian foal.     

500kV变电站的节能设计

为了降低500kV变电站的能耗，对变电站设备选型设计进行了详细的经济技术比较，选择了损耗较低的AsA主变压器、油浸式并联电抗器和非晶合金变压器，大大减小了变电站的损耗，具有广泛的社会经济效益。     

分流对弯道分流口门分布的影响

弯道水流运动所涉及的物理量较多,边界条件复杂多变,采用 vof 和 k-ε粘度模型模拟各个工况下的弯道分流,并利用室内弯道分流水槽模型试验结果对数值模型进行验证,在模型验证的基础上增加模拟变量和工况,对影响分水口水力特性的主要影响因素分流比和分流角度进行多组模拟。结果表明：在相同的分流比条件下,当分流角为30＆#176;和120＆#176;时的最大流速值较大。     

Hepatic Hepcidin Gene Expression in Dogs with a Congenital Portosystemic Shunt

Background

Microcytic anemia is common in dogs with a congenital portosystemic shunt (cPSS) and typically resolves after surgical attenuation of the anomalous vessel. However, the pathophysiology of the microcytic anemia remains poorly understood. Hepcidin has been a key role in controlling iron transport in both humans and animals and in mediating anemia of inflammatory disease in humans. The role of hepcidin in the development of microcytic anemia in dogs with a cPSS has not been examined.

Hypothesis

To determine whether hepatic hepcidin mRNA expression decreases, while red blood cell count (RBC) and mean corpuscular volume (MCV) increase in dogs after surgical attenuation of a cPSS.

Animals

Eighteen client‐owned dogs with confirmed cPSS undergoing surgical attenuation.

Method

Prospective study. Red blood cell count (RBC) and mean corpuscular volume (MCV), together with hepatic gene expression of hepcidin, were measured in dogs before and after partial attenuation of a cPSS.

Results

There was a significant increase in both RBC (median pre 6.17 × 10¹²/L, median post 7.08 × 10¹²/L, P < .001) and MCV (median pre 61.5fl, median post 65.5fl, P = .006) after partial surgical attenuation of the cPSS. Despite the increase in both measured red blood cell parameters, hepatic gene expression of hepcidin remained unchanged.

Conclusions and Clinical Importance

This study found no evidence that dysregulated production of hepcidin was associated with anemia in dogs with a cPSS.     

cis-Atracurium in dogs with and without porto-systemic shunts

OBJECTIVE: To evaluate the non-depolarizing neuromuscular blocking drug cis-atracurium in dogs with porto-systemic shunts, and to compare it in clinically normal animals. ANIMALS: Thirteen dogs of mixed breed and sex, aged between 3 and 31 months old, weighing 2.2-25.5 kg, with ASA physical status II-IV, and undergoing surgical attenuation of porto-systemic shunt. A control group of 11 bitches of mixed breed, between 8 and 60 months old, and weighing 4.5-41.0 kg, all ASA physical status I, undergoing routine ovarohysterectomy were also studied. MATERIALS AND METHODS: Pre-anaesthetic medication was an opioid analgesic, given either alone or in combination with acepromazine. Following induction of general anaesthesia with intravenous (IV) propofol and oro-tracheal intubation, anaesthesia was maintained using isoflurane in either oxygen or oxygen and nitrous oxide. Ventilation was controlled. The train of four (TOF) technique was used to monitor neuromuscular blockade. An initial dose of 0.1 mg kg(-1)cis-atracurium was given IV and additional doses of 0.03 mg kg(-1)cis-atracurium were administered when at least one twitch of the TOF was present. RESULTS: Except for one dog that was killed during surgery because its anomaly was inoperable, all animals recovered satisfactorily from anaesthesia and surgery. In dogs with porto-systemic shunt, onset of neuromuscular blockade was 3.1 +/- 1.1 minutes (mean +/- SD) and in control dogs was 3.4 +/- 0.7 minutes (not significantly different). Neuromuscular blockade lasted 34 +/- 13 minutes in dogs with porto-systemic shunt and 29 +/- 17 minutes in control dogs (not significantly different). CONCLUSIONS: The presence of porto-systemic shunt did not affect the rate of onset or duration of action of cis-atracurium. CLINICAL RELEVANCE: cis-Atracurium may have a use in veterinary anaesthesia for producing neuromuscular blockade in dogs with hepatic insufficiency, including those with porto-systemic shunt.     

IMAGING DIAGNOSIS—COMPLEX INTRAHEPATIC PORTOSYSTEMIC SHUNT IN A DOG

An unusual form of congenital intrahepatic portosystemic shunt was identified in a 3½-month-old female Labrador Retriever with neurologic signs. Ultrasonography and contrast-enhanced computed tomography were used to characterize the shunt morphology. An unusual, looping right-divisional shunt connected back to the portal vein that formed an ampula in the right-central portion of the liver. An irregularly shaped window-like opening connected the combined right-divisional loop and aneurysmal portal vein, and the caudal vena cava, while this vascular pool gradually fused more cranially. Imaging features of this complex vascular anomaly, which has not been previously reported, are presented.     

HELICAL COMPUTED TOMOGRAPHIC PORTOGRAPHY IN TEN NORMAL DOGS AND TEN DOGS WITH A PORTOSYSTEMIC SHUNT

Contrast enhanced helical computed tomography (CT) of the liver and portal system is routinely performed in human patients. The purpose of this project is to develop a practical protocol for helical CT portography in the dog. Ten clinically normal dogs were initially evaluated to develop a protocol. Using this protocol, ten dogs with confirmed portosystemic shunts (PSS) were then evaluated. Each patient was anesthetized, and a test dose of sodium iothalamate (400 mg I/ml) at 0.55 ml/kg was injected. Serial images were acquired at the level of T12-13 or T13-L1. The time to maximum enhancement of the portal vein was determined. This time period was used as the period between the second injection (2.2 ml/kg) and the start of the helical examination of the cranial abdomen. Delay times for normal dogs ranged from 34.5 s-66.0 s (median: 43.5 s) or 1.41 s/kg-4.12 s/kg (median: 2.09 s/kg). For patients with a PSS, the delay times were 16.5-70.5 s (median: 34.5 s) or 1.47-19.17 s/kg (median: 3.39 s/kg). The aorta, caudal vena cava, portal vein, shunt vessels, and their respective branches were well visualized on the CT images. Clinical case results were surgically confirmed. The surgeons reported that the information gained from the CT portography resulted in a subjective decrease in surgical time and degree of dissection necessary compared with similar surgeries performed without angiographic information. We believe that helical CT portography in the dog will be a useful adjunct in the diagnosis of PSS. The use of helical CT portography may allow clinicians to give clients a more accurate prognosis prior to surgery and will allow patients with lesions that are not surgically correctable to avoid a costly and invasive procedure.     

DIAGNOSIS OF ARTERIOPORTAL FISTULAE IN FOUR DOGS USING COMPUTED TOMOGRAPHIC ANGIOGRAPHY

Arterioportal fistulae are rare congenital anomalies of the hepatic vasculature. Diagnosis is conventionally made by selective angiography or ultrasonography. This report describes use of a dual-phase computed tomographic (CT) angiographic technique to diagnose arterioportal fistulae in four dogs. Advantages of this method include a noninvasive peripheral injection of contrast medium, ability to diagnose multiple acquired extrahepatic shunts, and observation of hemodynamic changes such as hepatofugal blood flow and reduced circulation to the caudal abdomen. The hepatic vasculature including arteries, veins, and portal veins can be completely evaluated. Dual-phase CT angiography is a safe and minimally invasive method of diagnosing arterioportal fistulae in dogs.