Impact of Early Urine Specimen Collection on Emergency Department Time to Disposition: A Randomized Controlled Trial.

Background Diagnostic testing in the ED increases the length of stay (LOS). Urinalysis testing is highlighted specifically as a source of delays. We aim to determine whether a triage-initiated urine specimen collection process decreases ED time to disposition (TTD) in ambulatory patients with abdominal pain. Methods This prospective, randomized controlled study was implemented at a Suburban Level One trauma ED with greater than 120,000 annual visits. A convenience sample of patients was recruited. Adult, non-ambulance patients presenting with abdominal pain were eligible. Participants were randomized into experimental and control groups. Patients in the control group provided a urine sample after physician evaluation, if ordered by the provider. Patients in the experimental group were prompted to provide a urine sample in the triage restrooms immediately after screening at the greeter desk. The UA sample was transported to the treatment area and sent to the laboratory after physician evaluation. Results A total of 125 control patients and 124 experimental patients were enrolled. Forty-two patients were excluded because they were unable to provide a urine sample. Patients who had a urinalysis ordered were included in statistical analysis. Final data set included 65 patients in the experimental group and 96 patients in the control group. No significant difference (p=0.5072) in disposition time between subjects in the experimental group (n=65, mean=5:17 [hours:min]) and subjects in the control group (n=96, mean=5:30) was found. Conclusions The triage protocol for urine specimen collection did not significantly reduce ED TTD. Further research in overcrowded EDs with long patient waiting room times may benefit from implementing a triage protocol for urine specimen collection.

Quantitative histomorphometric assessment of regenerate cellularity and bone quality in mandibular distraction osteogenesis after radiation therapy.

BACKGROUND: The use of mandibular distraction osteogenesis (MDO) for tissue replacement after oncologic resection in head and neck cancer could have immense therapeutic ramifications. We have previously demonstrated significantly decreased mechanical and microdensitomeric metrics of our MDO regenerate after 36-Gy radiation. Quantitative histomorphometry, a third metric, would permit objective investigation of the effects of radiation on tissue and cellular composition. Our hypothesis is that radiation-induced cellular depletion and diminution in function impair optimal bone regeneration. METHODS: Five rats received radiation to the left mandible; 5 received none. All animals underwent surgical placement of external fixators, creation of mandibular osteotomies, distraction to a 5.1-mm gap width, and consolidation. Point counting and color thresholding were performed. RESULTS: There was a significant increase in empty lacunae and a corresponding diminution in osteocytes after radiation. Whereas the volume fraction of mineralized, mature bone was not different, that of nonmineralized, immature osteoid was significantly increased in the radiated group compared with that in the nonradiated group. CONCLUSIONS: Our findings confirm our prior 2 metrics. Actually, all 3 diverse metrics--microdensitometry, biomechanical analysis, and histomorphometry--corroborate our hypothesis of cellular depletion and diminution of function as the potential mechanism of radiation-induced attenuation in the distracted regenerate. Furthermore, our findings of tissue and cellular changes in the irradiated regenerate elucidate the pathophysiology of decreased bone quality when amalgamated with our previous results. Therapeutic agents may now be introduced, and their effects on the irradiated regenerate critically measured, so that MDO may be used as a viable reconstructive option in patients with head and neck cancer.

Regenerate healing outcomes in unilateral mandibular distraction osteogenesis using quantitative histomorphometry.

BACKGROUND: The authors' goal was to ascertain regenerate bone-healing metrics using quantitative histomorphometry at a single consolidation period. METHODS: Rats underwent either mandibular distraction osteogenesis (n = 7) or partially reduced fractures (n = 7); their contralateral mandibles were used as controls (n = 11). External fixators were secured and unilateral osteotomies performed, followed by either mandibular distraction osteogenesis (4 days' latency, then 0.3 mm every 12 hours for 8 days; 5.1 mm) or partially reduced fractures (fixed immediately postoperatively; 2.1 mm); both groups underwent 4 weeks of consolidation. After tissue processing, bone volume/tissue volume ratio, osteoid volume/tissue volume ratio, and osteocyte count per high-power field were analyzed by means of quantitative histomorphometry. RESULTS: Contralateral mandibles had statistically greater bone volume/tissue volume ratio and osteocyte count per high-power field compared with both mandibular distraction osteogenesis and partially reduced fractures by almost 50 percent, whereas osteoid volume/tissue volume ratio was statistically greater in both mandibular distraction osteogenesis specimens and partially reduced fractures compared with contralateral mandibles. No statistical difference in bone volume/tissue volume ratio, osteoid volume/tissue volume ratio, or osteocyte count per high-power field was found between mandibular distraction osteogenesis specimens and partially reduced fractures. CONCLUSIONS: The authors' findings demonstrate significantly decreased bone quantity and maturity in mandibular distraction osteogenesis specimens and partially reduced fractures compared with contralateral mandibles using the clinically analogous protocols. If these results are extrapolated clinically, treatment strategies may require modification to ensure reliable, predictable, and improved outcomes.

Analysis of the biomechanical properties of the mandible after unilateral distraction osteogenesis.

BACKGROUND: The purpose of this study was to establish biomechanical outcomes measures to evaluate how mandibular distraction osteogenesis affects the overall quality of bone healing. Strength and functional integrity of the regenerate were determined quantitatively after unilateral mandibular distraction osteogenesis in comparison with the contralateral mandible and a partially reduced fracture. The authors hypothesized that the breaking load, yield, and stiffness of mandibular distraction osteogenesis would be significantly reduced in comparison with both the contralateral mandible and a partially reduced fracture. METHODS: Sprague-Dawley rats underwent mandibular distraction osteogenesis (n = 8) or a partially reduced fracture (n = 6). Distraction was performed using 4 days' latency and then 0.3 mm every 12 hours for 8 days (5.1 mm). Partially reduced fractures had gaps fixed postoperatively at 2.1 mm. Both groups underwent 4 weeks of consolidation. The contralateral mandibles were used as controls (n = 14). Mandibles were tension tested at 0.5 mm/second to failure, and then breaking load, yield, and stiffness were determined. RESULTS: Mandibular distraction osteogenesis had significantly lower breaking load, yield, and stiffness than contralateral mandible, by 40, 30, and 60 percent, respectively. Breaking load was reduced in partially reduced mandibular fractures by 40 percent when compared with distraction osteogenesis. CONCLUSIONS: Using a standard Ilizarov protocol, the biomechanical properties of breaking load, yield, and stiffness in mandibular distraction osteogenesis were significantly lower than those in contralateral mandibles. Surprisingly, the breaking load of mandibular distraction osteogenesis was significantly greater than that of partially reduced mandibular fracture. These verifiable metrics of regenerate integrity can be used to discern optimal outcomes of mandibular distraction osteogenesis, potentially enhancing the clinical applications of this powerful technique.

Biomechanical assessment of regenerate integrity in irradiated mandibular distraction osteogenesis.

BACKGROUND: The role of mandibular distraction osteogenesis for reconstructing mandibular defects following radiation therapy depends on the quality of attenuated bone healing in the regenerate. This study investigated the regenerate properties after radiation therapy using yield and breaking load. The authors hypothesized that both would be significantly reduced in mandibular distraction osteogenesis following radiation therapy compared with mandibular distraction osteogenesis alone. METHODS: Male Sprague-Dawley rats underwent left mandibular fractionated 36-Gy preoperative external beam radiation therapy and then 2 weeks of recovery (n = 7) or no radiation therapy (n = 10) before surgery. External fixators were secured and unilateral osteotomies were created behind the third molar, followed by 4 days of latency and then mandibular distraction osteogenesis: 0.3 mm every 12 hours for 8 days (5.1 mm) and 4 weeks of consolidation. Unoperated controls received no radiation therapy (n = 13). Mandibles were tension tested at 0.5 mm/second to failure, and yield and breaking load were determined. RESULTS: There was a significantly lower breaking load for mandibular distraction osteogenesis following radiation therapy compared with mandibular distraction osteogenesis, alone, but there was no significant difference in yield between the groups. Both groups had significantly lower breaking load and yield when compared with unoperated controls. CONCLUSIONS: The lowered breaking load in mandibular distraction osteogenesis following radiation therapy reflects the reduced biomechanical quality of the regenerate, despite evidence of radiographic union. These data show that radiographic union is not an adequate outcome measure for regenerate healing and support the need to define quantitative bone-healing metrics in mandibular distraction osteogenesis following radiation therapy before implementation in head and neck reconstruction.