Comparison between chloral hydrate and propofol-ketamine as sedation regimens for pediatric auditory brainstem response testing

Introduction The use of diagnostic auditory brainstem response testing under sedation is currently the “gold standard” in infants and young children who are not developmentally capable of completing the test. Objective The aim of the study is to compare a propofol-ketamine regimen to an oral chloral hydrate regimen for sedating children undergoing auditory brainstem response testing. Methods Patients between 4 months and 6 years who required sedation for auditory brainstem response testing were included in this retrospective study. Drugs doses, adverse effects, sedation times, and the effectiveness of the sedative regimens were reviewed. Results 73 patients underwent oral chloral hydrate sedation, while 117 received propofol-ketamine sedation. 12% of the patients in the chloral hydrate group failed to achieve desired sedation level. The average procedure, recovery and total nursing times were significantly lower in the propofol-ketamine group. Propofol-ketamine group experienced higher incidence of transient hypoxemia. Conclusion Both sedation regimens can be successfully used for sedating children undergoing auditory brainstem response testing. While deep sedation using propofol-ketamine regimen offers more efficiency than moderate sedation using chloral hydrate, it does carry a higher incidence of transient hypoxemia, which warrants the use of a highly skilled team trained in pediatric cardio-respiratory monitoring and airway management

Mechanical Evaluation of Fourth-Generation Composite Femur Hybrid Locking Plate Constructs

Locking compression plates are routinely used for open reduction and internal fixation of fractures. Such plates allow for locking or non-locking screw placement in each hole. A combined use of both types of screw application for stabilization of a fracture is commonly applied and referred to as hybrid internal fixation. Locking screws improve the stability of the fixation construct but at the expense of significant additional cost. This study experimentally analyzes various combinations of locking and non-locking screws under simultaneous axial and torsional loading to determine the optimal hybrid locking plate—screw construct in a fourth generation composite femur. Clinically it is necessary to ensure adequate fixation stability in a worse case fracture-bone quality scenario. A locking screw near the fracture gap increased the axial and torsional strength of the locked plate system. Greater removal torque remained in non-locked screws adjacent to locked screws compared to an all non-locking screws control group

Mechanical Evaluation of Fourth-Generation Composite Femur Hybrid Locking Plate Constructs

Locking compression plates are routinely used for open reduction and internal fixation of fractures. Such plates allow for locking or non-locking screw placement in each hole. A combined use of both types of screw application for stabilization of a fracture is commonly applied and referred to as hybrid internal fixation. Locking screws improve the stability of the fixation construct but at the expense of significant additional cost. This study experimentally analyzes various combinations of locking and non-locking screws under simultaneous axial and torsional loading to determine the optimal hybrid locking plate—screw construct in a fourth generation composite femur. Clinically it is necessary to ensure adequate fixation stability in a worse case fracture-bone quality scenario. A locking screw near the fracture gap increased the axial and torsional strength of the locked plate system. Greater removal torque remained in non-locked screws adjacent to locked screws compared to an all non-locking screws control group

The Protective Effect of Locking Screw Placement on Nonlocking Screw Extraction Torque in an Osteoporotic Supracondylar Femur Fracture Model

Objective: To examine the impact of number and position of locking screws in the diaphyseal portion of an osteoporotic distal femoral fracture model with hybrid fixation. Methods: Four groups containing 5 osteoporotic bone models were used with varying combinations of diaphyseal screw fixation: 4 nonlocking screws (control); 1 locking screw adjacent to the osteotomy and 3 nonlocking screws; 1 locking screw in the most proximal screw hole of the plate and 3 nonlocking screws; and 2 locking screws at opposite ends of the diaphyseal fixation with 2 nonlocking screws in between. Fixation in the distal articular segment was identical in all constructs. Testing was performed for 50,000 cycles at 2 Hz using simultaneous axial compression (700 N) and bidirectional torque (±5 Nm) applied along the long axis of the bone. All screws were inserted with 4 Nm of torque. Results: The extraction torque for nonlocking screws in those specimens that had a locking screw nearest the osteotomy was significantly greater than those that did not (P = 0.037). In addition, the 10 constructs with a locking screw nearest the osteotomy had no failures compared with 5 of 10 failures in those without a locking screw in this position (P = 0.033). Conclusions: The placement of a locking screw adjacent to the osteotomy was more beneficial in protecting against failure and maintaining the extraction torque of neighboring proximal nonlocking screws. No benefit in adjacent screw extraction torque was seen with a locking screw proximal in the diaphysis. Two locking screws at opposite ends of the diaphyseal fixation were not superior to a single locking screw adjacent to the osteotomy in failure rates or screw extraction torque