A comparison of the hemodynamic and ventilatory effects of abdominal insufflation with helium and carbon dioxide in young swine.

Abdominal CO2 insufflation has been shown to cause hypercarbia, acidemia, and decreased oxygenation in a pediatric animal model. Such metabolic derangements have prompted a search for alternative insufflation gases. This study compares the hemodynamic and ventilatory changes that occur during pneumoperitoneum with CO2 and helium. Four juvenile swine were intubated and given general anesthesia. Minute ventilation was adjusted to obtain a baseline Pco2 of between 32 and 36 mm Hg, and was kept constant for the duration of the experiment. The subjects initially were insufflated with CO2 or helium at a pressure of 10 mm Hg. Peak ventilatory pressure, end-tidal CO2 (ETCO2) arterial pH, Pco2, Po2, and right atrial and inferior vena caval pressures were measured before and during a 1-hour insufflation period. After desufflation, Pco2 and pH were restabilized. The same parameters were then measured during reinsufflation with the alternate gas. CO2 insufflation caused significant decreases in pH, from 7.51 +/- 0.03 to 7.32 +/- 0.06, and Po2 increased from 261 +/- 49 to 189 +/- 33 mm Hg. Pco2 increased from 35.0 +/- 1.4 to 57.9 +/- 6.3 mm Hg. ETCO2 also increased, from 29.0 +/- 2.2 to 47.2 +/- 5.0 mm Hg. Helium insufflation caused pH to decrease from 7.51 +/- 0.01 to 7.42 +/- 0.04. Pco2 increased from 32.8 +/- 0.8 to 43.5 +/- 3.9 mm Hg, and ETCO2 increased from 27.8 +/- 0.5 to 36.8 +/- 3.1 mm Hg. These alterations were significantly less than those with CO2 pneumoperitoneum. Po2 decreased as well-from 266 +/- 30 to 212 +/- 21 mm Hg. During insufflation with both gases, peak ventilatory pressure and right atrial pressure increased significantly. Abdominal insufflation with CO2 or helium causes hypercarbia, acidemia, and increased ETCO2 in this juvenile animal model. These derangements are significantly less with helium. This gas may prove to be the more suitable insufflation agent for pediatric patients.

Fractures of the radius and ulna.

Fractures of the radius and ulna are common in the dog and cat. If treated inappropriately, complications may result. These include delayed union, nonunion, malunion, and growth deformities. ESF is a versatile method of fixation for fractures of the radius and ulna. Types that are applicable range from the simple type I to the complex type III fixator. In general, the more unstable the fracture, the more rigid the assembly must be to counteract fracture forces. There are three basic phases to consider when using ESF: (1) preoperative planning, (2) application of the ESF, and (3) long-term management. A deficiency in any one of these phases can lead to complications and an unsatisfactory clinical outcome. Although ESF can be used on many types of fractures, the technique is especially well suited for open or highly comminuted fractures when internal fixation is not applicable. In these cases, close attention must be paid to the integrity of the soft tissues. In addition, cancellous bone grafts should be placed either at the time of initial repair or in a delayed fashion after adequate vascularity has been established. Staged or complete removal of the ESF should be individualized to each fracture case. In general, staged disassembly or "dynamization" can begin when the bone and fixator begin to function as a composite as determined by radiographs. Complete fixator removal should be considered when the fracture exhibits clinical and radiographic evidences of union.

Spindle cell sarcoma in the kidney of a dog.

A spindle cell sarcoma involving the left kidney was diagnosed in a 14-year-old male Basenji. Radiography and ultrasonography were used to define the extent and location of the mass. Metastatic disease was not detected. An 8 x 5-cm mass, involving the left kidney, was resected by performing nephroureterectomy. Signs of metastasis were not detected at 3 and 6 months after surgery. Shortly after the 6-month examination, the dog was euthanatized because of perceived signs of pain attributable to cervical disk disease. Postmortem examination was not performed. Histologic examination consisted of use of hematoxylin and eosin, Masson trichrome, and van Gieson stains, and 4 immunoperoxidase techniques. On the basis of the histologic findings, the final diagnosis was spindle cell sarcoma, with the 2 most likely possibilities being leiomyosarcoma and fibrosarcoma.

The effects of beveling the margins of articular cartilage defects in immature dogs.

Eight 4 month old crossbred puppies underwent surgery simulating treatment of osteochondritis dissecans. Both humeral heads were exposed by a caudal approach to the shoulder joint. In one, an 8 mm circular, full-thickness cartilage defect was created so that the remnant cartilage margin was perpendicular to the joint surface. In the other, a similar 8 mm defect was created with the chondral margins beveled at approximately 45 degrees. There was no clinical lameness in any of the dogs. At necropsy after 16 weeks, the cartilage defects with beveled edges were significantly larger (11.0 +/- 0.6 mm SD) than those with perpendicular edges (8.0 +/- 0.1 mm SD), because of the beveling (p = 0.0039). Fibrocartilage was present but did not always completely fill the defects. Articular surfaces of the glenoid cavities suffered erosion and fibrillation more frequently opposite beveled defects than opposite defects with vertical walls (p = 0.0312). This was presumably due to the larger apposing defect. It was concluded that the cartilage margins surrounding a chondral defect should not be beveled.

Thrombocytopenia associated with vaccination of a dog with a modified-live paramyxovirus vaccine.

Thrombocytopenia (10,000/mm3), with hematochezia and melena, appeared in a dog 8 days after it was given modified-live canine distemper, virus vaccine and persisted for approximately 5 days. Clinical investigation discounted other possible causes of thrombocytopenia; the condition was considered to be associated with vaccination. The problem spontaneously resolved. The appearance of thrombocytopenia after modified-live canine distemper virus vaccination is not unknown and may assume a severe form. This condition may be mistaken for idiopathic thrombocytopenia of immune origin, and in other instances, it may contribute significantly to surgical risk if concurrent coagulation disorders are present. Administration of levamisole HCl may alleviate the decrease in platelet count in affected animals.

Lipids of normal and osteochondritic cartilage of the immature canine humeral head.

Specimens of cartilage removed from the shoulder joint of dogs with osteochondritis dissecans were compared with the articular-epiphyseal cartilage from the same location of healthy dogs. The pathologic cartilage lost the lamination pattern of articular-epiphyseal cartilage from healthy dogs. Chondrocytes of healthy and pathologic cartilage contained lipid inclusions. However, in pathologic samples, the lipid inclusions were more prominent, particularly in the superficial region of the presumptive articular cartilage. Lipids in the interterritorial matrix of the pathologic cartilage were observed. The pathologic cartilage contained large groups of chondrocytes and areas of mineralization of variable magnitude. Although lipid inclusions were found in the chondrocytes of cartilage of healthy dogs, the increase in magnitude of lipids in the cartilage from dogs with osteochondritis dissecans was considered to result from a metabolic response of the chondrocyte to an altered microenvironment. The loss of sudanophilic lipids in areas of chondrolysis may be used to explain the retardation of osteogenesis of chondrolytic cartilage.