Pulmonary edema following postoperative laryngospasm: case reports and review of the literature.

Pulmonary edema that follows upper airway obstruction may occur in a variety of clinical situations. The predominant mechanism is forced inspiration against a closed or occluded glottis, inducing large intrapleural and transpulmonary pressure gradients favoring the transudation of fluid from the pulmonary capillaries into the interstitium. Postanesthetic laryngospasm has been implicated as the most frequent cause of this syndrome in adults. Risk factors for development of postlaryngospasm pulmonary edema include difficult intubation; nasal, oral, or pharyngeal surgical site; and obesity with obstructive apnea. The syndrome is recognized by development of hypoxia shortly (1-90 min) after a laryngospasm. A chest radiograph will reveal a symmetric bilateral infiltrate with normal heart size. Cardiogenic pulmonary edema and aspiration must be ruled out. Treatment is directed at correction of hypoxia with supplemental oxygen and use of diuretics (furosemide). Occasionally patients may require intubation.

Biomechanical evaluation of new fixation devices for mandibular angle fractures.

This biomechanical study investigated the effectiveness of fixation devices of simulated angle fractures in sheep mandibles. The fractures were stabilized by a Leibinger 8-hole three-dimensional (3-D) plate, a Synthes eight-hole mesh plate, and a Synthes six-hole reconstruction plate with 2.0-mm and 2.4-mm mono- and bicortical screws. Each mandible was tested in bending (class III cantilever model). The bone mineral density of the mandibles was measured by computed tomography scan. The Leibinger 3-D plate showed plate deformation in bending of > 230 N. None of the plates showed failure in the bone/screw interface. The gap and displacement values for the mesh and 3-D plate were comparable to those of the reconstruction plate. These results indicate that a 3-D or mesh plate can be used for fixation of mandibular angle fractures.

Prostaglandin release from rat femurs after implantation of hydroxylapatite and aluminium oxide ceramics.

The bony reaction after implantation of uncemented ceramics is of special interest. Therefore porous and dense hydroxylapatite and aluminium oxide ceramics were implanted in rat femurs. One group received no surgical manipulation and another with a sham procedure where no ceramics were implanted served as controls. After 6 and 10 days the rat femurs were harvested and the release of PGE2 and 6-keto-PGF1 alpha was measured with specific radioimmunoassays. Decrease in the release of PGE2 from day 6 to day 10 was present in all three implants. In contrast, 6-keto-PGF1 alpha increased from day 6 to day 10. Comparing the ceramic types an increase in 6-keto-PGF1 alpha release was seen in the porous hydroxylapatite group. These prostaglandin (PG) release patterns after ceramic implantation are similar to those of fracture healing, but aluminium oxide seems to be inert, while hydroxylapatite, especially the porous type, stimulates 6-keto-PGF1 alpha release.

Five-year follow-up of mandibular reconstruction with hydroxylapatite and the mandibular staple bone plate.

PURPOSE: To evaluate the results of hydroxylapatite augmentation of the mandible followed by placement of the mandibular staple. PATIENTS AND METHODS: Sixty patients 5 or more years postsurgery were evaluated. Patients were followed yearly with clinical and radiographic examinations. RESULTS: The decrease in augmentation height was 2.8 mm (33%) after the first year and only minimal in the following years. The following problems were seen: hyperplastic tissue around posts (eight patients), small dehiscences were seen in the saddle area after 2 years (11 patients), large dehiscences with significant hydroxylapatite loss in five patients. One patient needed a secondary augmentation. CONCLUSION: Prosthetic stabilization and function were excellent throughout the study period and there was a uniformly high degree of patient satisfaction.

Release of prostaglandins from bone and muscle after femoral osteotomy in rats.

In rats after nonstabilized femoral osteotomies, the changes in the release of prostaglandins (PGs) during bone healing (from bone and surrounding muscle tissue) were determined for PGE2, PGF2 alpha, 6-keto-PGF1 alpha, and thromboxane B2. A unilateral osteotomy, with contralateral soft-tissue dissection, was performed. After 4 or 10 days, the rats were killed and soft tissue and femoral bone were incubated, and the release of PGs was measured with specific radioimmunoassays. The release of PGs from rat femurs without previous surgery and from the sham-operated on side did not differ after 180 minutes' incubation. The release of PGE2, 6-keto-PGF1 alpha, and thromboxane-B2 from the osteotomy site was increased for bone on Day 4 and for muscle on Day 10 when compared with the controls. The release of PGF2 alpha from bone and muscle was about the same on both days, but increased as compared with the controls on Day 10 for bone. On Day 10, the other PGs for muscle and bone tissue were decreased as compared with Day 4. The most pronounced release of PGs occurred during the early healing phase after osteotomy; as early as 10 days after surgery, most of the PGs were not increased when compared with the sham-operated on side.

Biomechanical properties of resorbable poly-L-lactide plates and screws: a comparison with traditional systems.

Poly-L-lactide (PLA) plates and screws were tested in vitro in porcine ribs for uniaxial pullout and four-point bending strength. Results were compared to conventional systems (stainless steel and titanium). The biomechanical testing suggests that PLA screws have properties suitable for fixation of sagittal split osteotomies. Poly-L-lactide plates have indications in areas of low stress and noncompressive load.