PubMed Health⌕ Search

Biomedical subjects

C G Fisher

Publications and source records attributed to C G Fisher.

8 recordsLinked to original sources

Recognition and management of atlanto-occipital dislocation: improving survival from an often fatal condition.

OBJECTIVE: To provide an overview of atlanto-occipital dislocation and associated occipital condyle fracturcs so as to alert physicians to this rare injury and potentially improve patient outcome. The pertinent anatomy, mechanism of injury, clinical and radiologic evaluation and the management of these rare injuries are discussed in an attempt to alert physicians to this type of injury and to improve outcome. DATA SOURCES: The data were obtained from a MEDLINE search of the English literature from 1966 to 1999 and the experience of 4 spine surgeons at a quaternary care acute spinal cord injury unit. STUDY SELECTION: Detailed anatomic and epidemiologically sound radiology studies were identified and analyzed. Only small retrospective studies or case series were available in the literature. DATA EXTRACTION: Valid anatomic, biomechanical and radiologic evaluation was extracted from studies. Clinical data came from limited studies and expert opinion. DATA SYNTHESIS: Early diagnosis is essential and is facilitated by a detailed clinical examination and strict adherence to an imaging algorithm that includes CT and MRI scanning. When the dislocation is identified, timely gentle reduction and prompt stabilization throuigh nonoperative or operative means is found to optimize patient outcome. CONCLUSIONS: Atlanto-occipital dislocation should be suspected in any patient involved in a high speed motor vehicle or pedestrian collision. Once suspected, proper imaging and appropriate management of these once fatal injuries can improve survival and neurologic outcome.

Atlanto-Occipital Joint↗

Stopping nicotine exposure before surgery. The effect on spinal fusion in a rabbit model.

STUDY DESIGN: A double-blind, prospective, randomized study using a validated rabbit model of intertransverse process fusion. OBJECTIVES: To determine the effect of stopping prolonged nicotine exposure on autogenous bone graft incorporation in a rabbit lumbar spinal fusion model. SUMMARY OF BACKGROUND DATA: There is a growing body of evidence that systemic nicotine impairs healing of spinal fusions and fractures. However, it remains to be determined whether, if nicotine increases the nonunion rate of spinal fusion surgery, stopping nicotine exposure before surgery will negate this inhibitory effect. METHODS: Forty-seven rabbits were divided into two experimental groups and one control group. The two experimental groups were exposed to systemic nicotine for 8 weeks. Nicotine exposure was stopped in one group 1 week before surgery; nicotine exposure was continued in the other group throughout the study. All rabbits underwent an L5-L6 intertransverse process fusion with autogenous iliac crest bone graft. All rabbits were killed 35 days after surgery. Forty rabbits completed the study and underwent radiographic, biomechanical, and histologic testing. RESULTS: Fusion, as determined by a blinded examiner palpating the spine, occurred in 7 of 13 control rabbits, 4 of 13 rabbits that "quit" nicotine, and none of the 14 rabbits exposed to continuous nicotine. There was a statistically significant difference between the control and continuous nicotine (P = 0.0015) and between the discontinued nicotine and continuous nicotine groups (P = 0.025). Biomechanical testing showed no significant differences between groups (P = 0.11). A blinded musculoskeletal pathologist was unable to detect a difference between groups based on histologic analysis. CONCLUSIONS: Chronic nicotine exposure was shown to decrease spinal fusion rates. Discontinuing nicotine before surgery improved fusion rates.

Analysis of Variance↗

Effectiveness of pneumatic leg compression devices for the prevention of thromboembolic disease in orthopaedic trauma patients: a prospective, randomized study of compression alone versus no prophylaxis.

A prospective, randomized clinical trial in 304 orthopaedic trauma patients with hip and pelvic fractures was conducted to investigated the effectiveness of pneumatic sequential leg compression devices (PSLCDs) for the prevention of thromboembolic disease. The control group received no specific form of prophylaxis. Patients were followed by venous Doppler, duplex can, and ventilation perfusion lung scans. The study end-point was documented pulmonary embolism and/or deep vein thrombosis. The incidence of a venous thromboembolic event in the control group was 11% and in the experimental group 4%. This difference was statistically significant (p = 0.02). These patients were also stratified into hip and pelvic fracture groups. In the hip fracture patients, the control group had a thromboembolic event incidence of 12% and the experimental group 4%. This difference was also statistically significant (p = 0.03). In the pelvic fracture group there was a thromboembolic incidence of 11% in the controls, demonstrating this patient population to be at significant risk. In this group, the PSLCDs were not statistically shown to be effective. Pneumatic leg compression devices are effective in reducing the incidence of thromboembolic events in patients with hip fractures.

Adult↗

Neuromuscular blocking effects of succinylcholine in infants and children.

The neuromuscular blocking effects and recovery times following two doses of succinylcholine on a weight basis were evaluated in 16 infants and 16 children. Infants had less profound neuromuscular blockade than children at both 0.5 and 1.0 mg/kg doses. Succinylcholine, 1 mg/kg, in infants produced blockade equal to that produced by 0.5 mg/kg in children; at these equipotent doses there was no statistically significant difference between the times to recover to 10 and 90 per cent neuromuscular transmission in the two groups. However, the rate of recovery from 50 per cent neuromuscular transmission to 90 per cent neuromuscular transmission was 69.1 per cent/min in children, as opposed to 46.4 per cent/min in infants. When dosage was calculated on a surface area basis, there was a linear relationship for infants and children as a single group between the log dose and the times to recover to 50 and 90 per cent neuromuscular transmission. Similarly, there was a linear relationship between the log dose (mg/m2) and the maximum intensity of neuromuscular blockade.

Adult↗