Search PubMed⌕ Search

Biomedical subjects

A I MacKenzie

Publications and source records attributed to A I MacKenzie.

4 recordsLinked to original sources

Craniocervical stabilization using Luque/Hartshill rectangles.

Untreated craniocervical instability is associated with a high morbidity and a significant mortality. Existing methods using bone grafts, interlaminar wires, or acrylic eventually produce stability but require prolonged periods of immobility and have a high failure rate. The ideal method of fixation should provide for permanent correction of deformity and relief of symptoms, with immediate stabilization, at a single procedure. Posterior fixation of the occiput to a stable part of the cervical spine with a molded metal rectangle held in place by interlaminar wires was used to accomplish this. We report 20 patients treated consecutively who have undergone craniocervical fusion by this method using Luque/Hartshill rectangles. Fourteen patients had preexisting atlantoaxial instability and 6 had cord compression, but would become unstable after decompression. All operations were performed under general anesthesia; 9 patients (40%) were awake for intubation/positioning, and 7 patients had a simultaneous decompression. Sixteen patients made an uncomplicated recovery and became mobile 3 days postoperatively. Symptomatic and neurological improvement occurred in 70% of all patients. Neurological complications occurred in 4 patients (20%), reflecting the serious nature of the condition; 2 patients (10%) showed no change. Scrutiny of their presentations and operations failed to identify avoidable risk factors, except faulty wiring techniques. In all patients, permanent stabilization was achieved immediately, facilitating early mobilization with a real chance of improvement, which indicates that the method merits wider application.

Adolescent↗

Anaesthesia and cognitive functioning. Mental function in postoperative day patients at the time of their release.

Day care patients at Law Hospital, who had received either a general or a local anaesthetic in conjunction with minor surgery, were assessed by five tests of mental function before surgery and before discharge from hospital some hours after surgery. These patients did not perform differently from control patients, who were subjected to the same two testing sessions, without intervening surgery or anaesthesia. It was concluded that the day cases were quite capable of normal cognitive functioning at the time of their discharge and that the procedures followed by the hospital for the discharge of day cases are generally adequate.

Adult↗

Ventilator problems caused by humidity in the air supplied from simple compressors.

Relative humidity of air produced by simple compressors used to drive ventilators was measured at different working pressures. At normal working pressures, a relative humidity of 100% was found and condensation occurred, mainly at the high pressure air/oxygen mixer valve. This resulted in blockages and loss of accuracy which could have serious consequences for patients. It was concluded that simple compressors are unsuitable and that medical air must be used.

Air↗